Search Results (31)

Thermal degradation of polydimethylsiloxane (PDMS)-based silicone sealants was investigated using evolved gas analysis (EGA) for rapid temperature screening, combined with multistep pyrolysis gas chromatography with mass spectrometric detection. The identified products were cyclic siloxanes, ranging from hexamethyl cyclotrisiloxane to hexadecamethyl cyclooctasiloxane. Aged and weathered sealants showed distinctly lower siloxane evolution temperatures (450–510 °C) compared to fresh samples (610–710 °C), indicating more facile polymer degradation. This trend was evident in both EGA-MS and Py-GC-MS, with EGA-MS showing a more pronounced effect, suggesting its potential for detecting sealant failure. Notably, the total evolved amounts of specific siloxanes remained nearly constant, suggesting that weathering primarily affects the thermal evolution profiles rather than the overall PDMS structure. The abundance of the three largest-size siloxanes increased (3–7%) with the weathering; in contrast, the changes in the amounts of the most abundant siloxanes were insignificant throughout all samples, regardless of the extent of weathering. These observations suggest that weathering induces changes in details of material structure, e.g., intermolecular interactions, rather than substantial chemical alterations to the PDMS structure. Full article

Mass spectrometry (MS) and coupled gas chromatography-mass spectrometry (GC-MS) are globally recognized as the primary techniques for the analysis of gases or vapors due to their selectivity, sensitivity, accuracy, and reproducibility. When thermal stress is applied, vapors or gases are released as a result of the reactions and changes that occur. The analysis of these gases during the thermally induced reaction is scientifically referred to as evolved gas analysis (EGA), which is essential for confirming the occurrence of the induced reactions. Pyrolyzers, thermobalances, or simple heaters can increase the temperature of the analyzed samples according to a programmed and software-managed ramp, allowing for control over both the heating rate and isothermal stages. The atmosphere can also be varied to simulate pyrolysis or thermo-oxidative processes. This way, each induced reaction generates a unique evolved gas, which can be linked to a theoretically hypothesized mechanism. Mass spectrometry (MS) and coupled gas chromatography–mass spectrometry (GC-MS) are fundamental analytical methods used for on-line thermally induced evolved gas analysis (OLTI-EGA). Full article

e-Games have become increasingly important in supporting the development of children with language delays. However, most existing educational games were not designed using usability guidelines tailored to the specific needs of this group. While various general and game-specific guidelines exist, they often have limitations. Some are too broad, others only address limited features of e-Games, and many fail to consider needs relevant to children with speech and language challenges. Therefore, this paper introduced a new collection of usability guidelines, called eGLD (e-Game for Language Delay), specifically designed for evaluating and improving educational games for children with language delays. The guidelines were created based on Quinones et al.’s methodology, which involves seven stages from the exploratory phase to the refining phase. eGLD consists of 19 guidelines and 131 checklist items that are user-friendly and applicable, addressing diverse features of e-Games for treating language delay in children. To conduct the first validation of eGLD, an experiment was carried out on two popular e-Games, “MITA” and “Speech Blubs”, by comparing the usability issues identified using eGLD with those identified by Nielsen and GUESS (Game User Experience Satisfaction Scale) guidelines. The experiment revealed that eGLD detected a greater number of usability issues, including critical ones, demonstrating its potential effectiveness in assessing and enhancing the usability of e-Games for children with language delay. Based on this validation, the guidelines were refined, and a second round of validation is planned to further ensure their reliability and applicability. Full article

Background: Cognitive control (CC) underpins our ability to maintain task focus, update goals, and flexibly shift between strategies, and it is closely tied to prefrontal cortex (PFC) activity. Electronic gaming (e-gaming), such as the first-person shooter (FPS) genre, is a specialized domain that demands refined CC skills developed over years of practice. Although previous research has demonstrated that PFC hemodynamic activity can effectively evaluate CC in several skilled domains, the impact of prolonged FPS experience on CC and its underlying neural correlates remains unclear. Objectives: In this study, we examined differences in both behavioral performance and PFC hemodynamic responses between 70 novices and 50 experienced FPS gamers (n=120). Methods: We targeted three core CC subdomains—updating, shifting, and inhibition—by employing the Digit–Symbol Substitution Task, Dual Visual Search Task, and Stroop Task, respectively. Functional near-infrared spectroscopy (fNIRS)-based PFC activity was recorded as participants engaged in each task. Results: Experienced gamers showed higher levels of prefrontal neural efficiency for updating and shifting, but minimal differences for inhibitory control. Conclusions: These findings inform neuroergonomic approaches to performance evaluation and may be generalized to other complex, real-world environments that rely on extensive training for skill acquisition. Full article

The polymorphism of the ultraviolet luminescent security ink Orlyum White 520T (N-(2-(4-oxo-4H-benzo[d][3,1]-oxazin-2-yl)phenyl)naphthalene-2-sulfonamide) is revealed, obtaining two new polymorphic forms with enhanced stability. Beyond the known form (lit. mp. 184.8–185.2 °C, Form III, YOCTAO), we succeeded in gaining two new polymorphic forms, Form II and Form I, with higher melting points of 195–196 and 197–198 °C, respectively. Their elemental composition, ¹H and ¹³C NMR spectra have been found to be identical, while their powder XRD patterns and FT-IR spectra are significantly different. Based on the single-crystal structure determination of Form II and redetermination of Form III, we uncover the similarities and differences in their packing arrangement and in their secondary interaction systems, all of which affect the molecular conformations in their crystals. In order to explain their significantly distinguishable melting points, Hirshfeld surface analysis and lattice energy calculations have also been carried out. We have made efforts toward revealing the reproducible conditions under which certain polymorphs are formed. It seems that the solvents or other probable organic contaminations are more likely responsible for the formation, nucleation and growth of crystals of various polymorphic forms, traced by thermogravimetric evolved gas analysis (TG/DTA-EGA-MS). Full article

Quantifying basal area in terms of diameter classes is important for informing forest management decisions. It is commonly derived from stand diameter distributions using field measurements, LiDAR, and a distribution function. This study compares alternative methods for directly estimating basal area in three tree diameter classes that are relevant to timber operations and wildlife habitat planning in southern United States pine forests. Specifically, linear modeling, ensemble linear modeling (ELM) and ensemble general additive modeling (EGAM) were compared. The results showed that the EGAM method provided the highest r-squared values and the lowest RMSE, and the ELM method provided good interpretability and 30 times faster processing than the EGAM method. Both ensemble methods produced a spatially explicit standard error estimate output without additional steps, unlike the single linear model. In general, the estimation results of this study were comparable or improved over prior studies’ estimates of basal area by tree diameter class. Full article

Addressing human trafficking is crucial due to its severe impact on human rights, dignity, and well-being. Serious games refer to digital games that are designed to entertain while also accomplishing at least one additional objective, such as learning or health promotion. Serious games play a significant role in raising awareness, training professionals, fostering empathy, and advocating for policy improvements related to human trafficking. In this study, we systematically examine and assess the current landscape of serious games addressing human trafficking to unveil the existing state, pinpoint gaps, and propose future research avenues. Our investigation encompassed academic publications, gray literature, and commercial games related to human trafficking. Furthermore, we conducted a thorough review of evaluation criteria and heuristics for the comprehensive assessment of serious games. Subsequently, incorporating these evaluation metrics and heuristics, the games were subjected to evaluation by both players and experts. Following a combined qualitative and quantitative analysis, the results were deliberated upon, and their implications were expounded. Five serious games related to human trafficking were identified and evaluated using the SGES and EGameFlow scales, along with both game-specific and serious game heuristics. Player and expert evaluations ranked “(Un)TRAFFICKED” and “Missing” as the best-performing games, while “SAFE Travel” received the lowest ratings. Players generally rated the games higher than experts, particularly in usability, feedback, and goal clarity, although the games scored poorly in audiovisual quality and relevance. Experts highlighted deficiencies in motivation, challenge, and learning outcomes. The lack of personalization and the absence of social gaming elements point to the need for more targeted human trafficking games adapted to different demographics, cultures, and player types. Full article

This article explores the use of olive pit powder (OPP) as a promising resource for enhancing the thermal insulation properties of epoxy mortars. A comprehensive analysis of the chemical and physical characteristics of OPP was conducted, employing analytical techniques including scanning electron microscopy (SEM), thermogravimetric analysis and emitted gas analysis (TG-MS-EGA), and proximal analysis. Experimental samples of epoxy grout were prepared by using different proportions of a conventional inorganic filler, quartz powder, and OPP within an epoxy mortar matrix. As the percentage of OPP in the formulation increased, the microstructure of the samples gradually became more porous and less compact. Consequently, there was a decrease in density with the increase in OPP content. The 28-day compressive strength decreased from 46 MPa to 12.8 MPa, respectively, in the samples containing only quartz (Sample E) and only OPP (Sample A) as a filler. Similarly, flexural strength decreased from 35.2 to 5.3 MPa. The thermal conductivity decreased from 0.3 W/mK in Sample E to 0.11 in Sample A. Therefore, increasing the %wt of OPP improved insulating properties while reducing the mechanical resistance values. This study highlights the potential of OPP as an environmentally friendly and thermally efficient filler for epoxy mortars, thereby promoting sustainable construction practices. Full article

The rise of professional careers in playing sports has been seen in the recent generation. Ranging from traditional sports to recent e-games, it can be seen that student athletes are not only considering these as motivational factors for education, but also as future career paths. This study aims to fill the knowledge gap about the factors influencing college athletes’ aspirations to play professionally. The study examines the complex web of athlete decision-making by utilizing the extended Theory of Planned Behavior (TPB) and analyzing the roles of motivational factors, self-efficacy, affective behavior, and behavioral domains. With the use of structural equation modeling, the study deciphers the intricate links, emphasizing the critical role that attitude plays in affective behavior. It emphasizes how much optimism and self-efficacy shape an athlete’s behavior and subsequent pursuit of professional careers. The current research provides a benchmark for future studies exploring student athletes’ career goals. This research adds understanding to the knowledge gap regarding the complex decision-making procedures of aspiring professional athletes. Both theoretical and practical implications are provided based on the results of the study, which stakeholders and institutions may consider for student athletes wanting to pursue a professional sports career. Full article

The MiniMovers (MM) APP combines motor development theory with creativity expertise and has been designed to provide parents with developmentally appropriate activities to support children’s motor skills. This study investigates how MiniMovers activities enabled parents to support their children’s physical development. Families participated in an 8-week MM programme of activities from the MM APP (Mini, Mighty and Mega levels), with pre- and post-intervention data collected using multiple tools (e.g., motion capture system, force plate, eye-tracking glasses, and videos). Mixed research methods were applied among children (N = 8; aged 21–79 months) and their parents, providing quantitative analysis on children’s performance (running, throwing, jumping, kicking, balancing and catching), as well as qualitative analysis on parents’ attitude and behaviour (two-weekly feedback surveys and interviews). Lab-based measures showed significant improvements in run time, underarm throwing distance, and horizontal jump distance. Test of Gross Motor Development-3 showed a significant gain in running, underarm and overarm throwing, horizontal jump and kicking. Further, developmental stages indicated significant improvements in running, kicking and catching. Parents reported increased enjoyment and knowledge, children’s enjoyment, independence and confidence. This pilot study provides support for the research and development of the MM App and suggests more research into the use of APPs to support home activities among families with young children. Full article

This study aimed to compare the aroma profiles of Sorbara and Spergola grapevine prunings roasted at different temperatures (120, 140, 160, 180, 200, and 240 °C). One potential application of grapevine prunings is their use as infusion chips to enhance and improve the aging processes of alcoholic beverages and vinegars. Aromatic compounds impart unique flavors and contribute to the complexity of the final products. Thermogravimetry–mass spectrometry coupled with evolved gas analysis (TGA-MS-EGA) was conducted to identify the thermal steps at which substantial changes occurred in the wood matrix. Solid-phase microextraction–gas chromatography–mass spectrometry (SPME-GC-MS) was used for the analysis of volatile compounds. Several key volatile compounds were identified, showing variations in their concentrations as a function of cultivar and roasting temperature. Furan derivatives, such as furfural, and phenolic compounds, such as guaiacol and vanillin, were the two main chemical classes of volatile compounds that predominantly defined the aroma of grapevine chips roasted above 180 °C. At lower roasting temperatures, some aldehydes, such as hexanal and terpenes, defined the aroma profiles of the samples. By repurposing waste materials, this application offers a pathway for environmentally conscious viticulture and sustainable practices within the food industry. Full article

Acrylonitrile butadiene styrene (ABS) is a thermoplastic polymer widely used in several everyday life applications; moreover, it is also one of the most employed plastics in contemporary artworks and design objects. In this study, the chemical and thermal properties of an ABS-based polymer and its photo-degradation process were investigated through a multi-analytical approach based on thermal, mass spectrometric and spectroscopic techniques. LEGO^® building blocks were selected for studying the ABS properties. First, the composition of unaged LEGO^® bricks was determined in terms of polymer composition and thermal stability; then, the bricks were subjected to UV–Vis photo-oxidative-accelerated ageing for evaluation of possible degradation processes. The modifications of the chemical and thermal properties were monitored in time by a multi-technique approach aimed at improving the current knowledge of ABS photodegradation, employing pyrolysis online with gas chromatography and evolved gas analysis, coupled with mass spectrometric detection (Py-GC-MS and EGA-MS), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and corroborated by external reflection FT-IR spectroscopy. The multimodal approach provided new evidence on the two-step degradation pathway proposed for ABS, defining molecular markers for polybutadiene oxidation and styrene-acrylonitrile depolymerization. Moreover, the results highlighted the feasibility of correlating accurate compositional and thermal data acquired by bulk techniques with external reflection FT-IR spectroscopy as a non-invasive portable tool to monitor the state of conservation of plastic museum objects in-situ. Full article

Here, seven new double-complex salts, [M¹(NH₃)₆][M²(C₂O₄)₃] (M¹, M² = Co, Rh) and K₃[Rh(NH₃)₆][Rh(C₂O₄)₃]₂∙6H₂O types, are synthesised. The crystal structure and composition of DCS (double-complex salts) are studied by SCXRD, XRD, CHN and IR methods. The complex salts of the [M¹(NH₃)₆][M²(C₂O₄)₃] (M¹, M² = Co, Rh) type can be crystallised both as a crystalline hydrate [M¹(NH₃)₆][M²(C₂O₄)₃]·3H₂O (sp. gr. P-3) and as an anhydrous complex (sp. gr. P-1) depending on the synthesis conditions. The process of [Rh(NH₃)₆][Rh(C₂O₄)₃] formation is significantly dependent on the synthesis temperature. At room temperature, a mixture is formed comprising [Rh(NH₃)₆][Rh(C₂O₄)₃] and K₃[Rh(NH₃)₆][Rh(C₂O₄)₃]₂∙6H₂O, while the [Rh(NH₃)₆][Rh(C₂O₄)₃] target product crystallises at elevated temperatures. The thermal behaviour of double-complex salts is studied by the STA, EGA-MS, IR and XRD methods. The complete decomposition of complex salts in helium and hydrogen atmospheres resulting in metals or Co_xRh_1−x solid solutions is achieved at temperatures of 320–450 °C. Full article

Apricot (AS), peach (PS), and plum shells (PlS) were examined as sustainable aggregates for non-structural lightweight concrete. The extraction of natural resources has a significant environmental impact and is not in line with the Sustainable Development Goals (SDGs) of Agenda 2030. Recycling agri-food waste, such as fruit shells, fully respects circular economy principles and SDGs. The chemical and physical properties of the shells were investigated using scanning electron microscopy (SEM) for microstructure analysis and TG-MS-EGA for thermal stress behavior. Two binding mixtures were used to prepare the concrete samples, one containing lime only (mixture “a”) and one containing both lime and cement (mixture “b”). Lime is a more sustainable building material but it compromises mechanical strength and durability. The performance of lightweight concrete was determined based on the type of aggregate used. PS had a high-water absorption capacity due to numerous micropores, resulting in lower density (1000–1200 kg/m³), compressive strength (1–4 MPa), and thermal conductivity (0.15–0.20 W/mK) of PS concrete. AS concrete showed the opposite trend (1120–1260 kg/m³; 2.8–7.0 MPa; 0.2–0.4 W/mK) due to AS microporosity-free and denser structure. PlS has intermediate characteristics in terms of porosity, density, and water absorption, resulting in concrete with intermediate characteristics (1050–1240 kg/m³; 1.9–5.2 MPa; 0.15–0.3 W/mK). Full article

Among the innovative materials used by 20th-century artists, polyurethane (PUR) has been shown to be highly unstable, and therefore artworks made of it are now in need of careful conservation strategies. This study presents a multi-analytical investigation of PUR foam scenic objects originally made between the 1960s and 1970s during the Italian Arte Viva movement. The main components in the foam and additives were characterized through micro attenuated total reflectance infrared spectroscopy (μ-ATR-FTIR) and pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC/MS). Painted samples were further investigated through μ-FTIR and Raman spectroscopy to define binders and pigments. The use of μ-ATR-FTIR in combination with evolved gas analysis-mass spectrometry (EGA-MS) allowed the variable conditions of the artworks to be assessed and attained some insights into the chemical processes responsible for aging. At the same time, morphological changes due to the degradation phenomena were recorded through optical (OM) and scanning electron microscopy (SEM). The detailed characterization of the PUR foam and painting materials was helpful in attaining some insights into harmful environmental parameters for the artworks, thus informing preventive conservation. Full article