Search Results (45)

This article examines Daoist ritual and meditative practices, primarily developed between the fourth and twelft centuries, as cosmotechniques: methods for engaging, recalibrating, and occasionally overturning the spatial and temporal order. It first outlines the cosmological framework of the pre-Qin and Qin–Han periods, in which space and time were conceived as correlative and qualitative, forming the grounds of Daoist practice. Daoist foundational practices elaborately aligned with this framework but also introduced subtle disruptions that discover the singular space–time for transformation. Through the investigation of bodily cultivation and communal rituals, this study argues for attention to the performative aspect of Daoist practices, aiming to access and enact alternative space–time, and suggesting a dynamic interplay between alignment and disruption. The study further analyzes internal alchemy and visionary practices that engage in radical reversals of natural rhythms—employing fire, dissolution, and systemic negation to reconfigure cosmic flow. As shown here, Daoist practice is not merely contemplative but performative, reconstituting space–time and body. Though not articulated in ecological terms, such practices demonstrate ways of modeling and modulating lifeworlds attuned to the rhythms of nature—pointing to the possibility of reshaping life under unplugged conditions. Full article

In the realm of click-type reactions and their application to bioorthogonal chemistry in living organisms, metal-free [3+2] cycloadditions involving mesoionic rings and strained cycloalkynes have gained increasing attention and potentiality in recent years. While there has been a significant accretion of experimental data, biological assays, and assessments of reaction mechanisms, some pieces of the tale are still missing. For instance, which structural and/or stereoelectronic effects are actually interlocked and which remain unplugged. With the advent of data-driven methods, including machine learning simulations, quantitative estimations of relevant observables and their correlations will explore better the chemical space of these transformations. Here we unveil a series of linear relationships, such as Hammett-type correlations, as well as deviations of linearity, using the case study of phenylsydnone (and its 4-aryl-substituted derivatives) with a highly reactive bicyclo[6.1.0]nonyne carbinol. Through accurate estimation of activation barriers and prediction of rate constants, our findings further increase the significance of integrating strain release and electronic effects in organic reactivity. Moreover, such results could pave the way to use mesoionics cycloadditions as probes for measuring the extent of delocalization-assisted strain release, which can be applied to related reactions involving dipoles and strained rings. Full article

Augmented consumerism has propelled electronic innovation, leading to unprecedented growth in e-waste. Mishandling of e-waste poses environmental and human health hazards that necessitate a review of existing technologies and regulatory frameworks for effective e-waste management. Over the years, advancements in e-waste treatment technologies have addressed challenges uncovered in conventional e-waste treatment methods. This review comprehensively discusses valorization, regulations, and the environmental and health hazards imposed by e-waste mismanagement. The review adopted the novel VIRE framework to justify the research question and followed PRISMA analysis to filter the research basket. This study highlights that progressive policy frameworks are less efficient until inhibiting factors for successful implementation are addressed, especially in developing countries. The informal sector dominates in impeding the successful implementation of e-waste regulations, requiring integration with the formal sector as an initiative to reduce unlawful e-waste handling. Moreover, e-waste holds significant potential for economic value through precious metal recovery. An integrated approach of thermal techniques followed by bioleaching could be a cost-effective alternative for enhanced metal recovery from e-waste. There exists ample opportunity for further advancement in treatment technologies through the integration of discrete techniques, reframing regulatory frameworks to minimize unauthorized processing, and cooperative international agreements for collective action on sustainable e-waste management. Full article

The results of core flooding experiments can guide the formulation of development plans for similar oil reservoirs. However, for cores from heavy oil reservoirs, asphaltene deposition often occurs during flooding due to changes in pressure, temperature, and petroleum composition, affecting the determination of injection parameters. Taking core samples from the Xia 018 well block as the research object, this study determined that the crude oil sample exhibits normal CO₂ sensitivity based on PVT experiments and core flooding results. A corresponding asphaltene precipitation model was established and coupled with core-scale numerical simulation, forming an integrated core-scale numerical simulation method considering asphaltene precipitation. Through orthogonal experimental design, the optimized fracturing production parameters for Well Y were determined as follows: fracturing stage length of 1000 m, CO₂ injection volume of 100 m³ per stage, fluid volume per stage of 1000 m³, proppant volume of 1000 m³, and injection rate of 14 m³/min. Finally, the optimized parameters were applied to simulate a case well, where the asphaltene deposition model combined with pressure nephograms during production provided effective guidance on unplugging timing. Compared with results without using the asphaltene deposition model, cumulative production decreased by 1300 m³ when the model was applied. These findings can provide a reference for the development of similar reservoirs. Full article

Low-frequency electromagnetic fields, induced by alternating current (AC)-based equipment such as transformers, are known to influence the physicochemical properties and function of enzymes, including their catalytic activity. Herein, we have investigated how incubation near a 50 Hz AC autotransformer influences the physicochemical properties of horseradish peroxidase (HRP), by atomic force microscopy (AFM) and spectrophotometry. We found that a half-hour-long incubation of the enzyme above the coil of a loaded autotransformer promoted the adsorption of the monomeric form of HRP on mica, enhancing the number of adsorbed enzyme particles by two orders of magnitude in comparison with the control sample. Most interestingly, the incubation of HRP above the switched-off transformer, which was unplugged from the mains power supply, for the same period of time was also found to cause a disaggregation of the enzyme. Notably, an increase in the activity of HRP against ABTS was observed in both cases. We hope that the interesting effects reported will emphasize the importance of consideration of the influence of low-frequency electromagnetic fields on enzymes in the design of laboratory and industrial equipment intended for operation with enzyme systems. The effects revealed in our study indicate the importance of proper shielding of AC-based transformers in order to avoid the undesirable influence of low-frequency electromagnetic fields induced by these transformers on humans. Full article

This study examined the effectiveness of video self-modeling in teaching unplugged coding skills to children with autism spectrum disorder (ASD). The participants included one female and three male children with ASD, ages 10 to 12, in a multiple-probe design across subjects. The findings demonstrated that video self-modeling successfully facilitated the acquisition of unplugged coding skills for all four students. Additionally, all participants could generalize these skills to a new setting, and for those assessed, the skills were maintained for up to 12 weeks after the intervention. Social validity data collected from participants and their parents indicated positive perceptions of the approach. This study’s results highlight implications for instructional practices and future research. Full article

This study reports on a STEM camp that aimed to engage middle grade students in computational thinking dispositions. Case study methodology and data from observational field notes and participant reflections were used to investigate if and how students engaged in computational thinking dispositions as they engaged in the unplugged LEGO activities. The findings revealed that unplugged structured LEGO activities (a) did not facilitate tolerance for ambiguity, (b) facilitated high persistence on difficult problems, and (c) high and developing willingness to collaborate with others to achieve a common goal. The findings also revealed that unplugged semi-structured LEGO activities (a) facilitated high and developing tolerance for ambiguity, (b) facilitated no evidence of persistence, and (c) increased and developed willingness to collaborate with others to achieve a common goal. The overall findings of this study suggest that when using unplugged, LEGO activities: (a) it is better to use unplugged structured LEGO activities to promote the computational thinking disposition of persistence, (b) it is better to use semi-structured activities to promote tolerance for ambiguity, and (c) it is better to use either or both to promote collaboration with others to achieve a common goal. The study’s findings are significant because it provides an empirical example of how the use of LEGOS as an unplugged activity can be used to facilitate computational thinking dispositions in middle grade students. Having this information is important because it can support STEM educators in modifying and adapting unplugged LEGO activities to develop students’ computational thinking dispositions. Full article

In the era where digital technologies are becoming increasingly prevalent, it is anticipated that a majority of the global population will have at least a basic understanding of informatics. However, empirical evidence suggests that a significant portion of the global population remains digitally illiterate. This phenomenon is particularly pronounced in the case of the senior adult population. In light of the aforementioned challenges, this work integrates Computer Science Unplugged exercises, based on games and recreational activities without the use of computers, and L2T2L, a learning-by-teaching methodology whereby university students learn and then, in turn, teach that learning to other populations in a cascading manner. A case study was conducted in Lima, Peru, with the participation of 140 volunteers from centres for the elderly. Thirty-five students and one teacher from the Universidad Científica del Sur were responsible for initiating the transfer of knowledge from the university to the senior citizens, with the assistance of twelve individuals responsible for their care. The results demonstrate that the participants attained a commendable level of comprehension when attempting to complete all of the assigned tasks. Furthermore, the efficacy of L2T2L is evident in its adaptability and suitability for scenarios beyond those for which it was originally designed. Full article

This study investigates the impact of excessive mobile phone use on young individuals aged 14–35 in Kastoria, Greece. It explores how smartphone addiction affects daily life and social interactions. A survey with 30 closed-ended questions was conducted among 150 respondents from May to August 2019. Data were analyzed using descriptive statistics and chi-square tests, focusing on gender and employment status differences. Most respondents use their phones for over 5 h daily, primarily for social media and communication. Findings reveal high addiction rates, reduced productivity, and disrupted sleep. Women reported more difficulty disconnecting and a greater need for detoxification than men. Students and unemployed individuals showed higher addiction symptoms and negative productivity impacts compared to employed respondents. Excessive mobile phone use among young people poses significant challenges, including addiction and adverse effects on productivity, relationships, and sleep, influenced by gender and employment status. Full article

Coding and computational thinking (CT) are important skills to include in early childhood education. Measuring these vital skills in preschool-age children can be challenging. We modified the TechCheck-PreK assessment, an unplugged measure of CT for 3-to-5-year-old children, to increase reliability and to add foundational coding concepts. We created the Coding Readiness Assessment (CRA) from a subset of nine TechCheck-PreK items and twelve new items that assess additional CT and coding readiness constructs. In an initial feasibility study of the CRA, teachers observed impulsive responses by children. We mitigated this by implementing a brief delay between the appearance of the question and the timeframe in which children could respond. In a subsequent randomized control trial, the CRA was administered 1637 times by Head Start educators. The assessment took an average of 9.8 min to administer. CRA scores were normally distributed and increased on average as a function of age. Girls scored slightly higher than boys, although the difference was not significant when age and race were taken into account. The CRA showed acceptable levels of reliability in terms of internal consistency (α = 0.78) and test–retest reliability (r = 0.65). Results from a 3PL indicate that the CRA has suitable levels of difficulty and skill level discrimination for 3-to-5-year-olds. The 3PL guessing parameter was 0.28, indicating that steps to reduce impulsive responses were successful. We conclude that the CRA has suitable properties for assessing preschool-age children’s CT skills and coding readiness. Full article

The application of wireless power transfer (WPT) technology in power replenishment for drones can help to solve problems such as the frequent manual plugging and unplugging of cables. A wireless power replenishment system for drones based on the transmitter design with multiple annular-sector-shaped coils is proposed in this paper, which improves the misalignment tolerance of couplers, enlarges the drone landing area, and reduces the control requirements of drone landing accuracy further. The general analysis model of the proposed transmitter and the numerical calculation method for mutual inductance between energy transceivers are established. Then, the effect of multiple parameters of the proposed transmitter on the variation in mutual inductance is studied. The misalignment tolerance improvement strategy based on the optimization of multiple parameters of the transmitter is investigated. Finally, an experimental prototype of a wireless power replenishment system for drones based on LCC-S compensation topology is designed to validate the theoretical research. Under the same maximum outer radius of 0.20 m and the same mutual inductance fluctuation rate of 5%, compared to single circular transmitter mode, the maximum offset distance of all directions (360 degrees) in the x-y plane is increased from 0.08 m to 0.12 m. As the receiving side position changes, the maximum receiving power and efficiency are 141.07 W and 93.79%, respectively. At the maximum offset position of 0.12 m, the received power and efficiency are still 132.13 W and 91.25%, respectively. Full article

Computational thinking (CT) can be developed in a multitude of ways. Well-known examples are plugged-in and unplugged applications that focus primarily on the (combined) usage of visual, textual, or tangible modalities. Less obvious are applications where CT development can be established via an auditory modality, to which the importance of creativity is attributed. When reasoning from such a different contextual perspective, it is interesting to investigate whether the self-creation of electronic music influences CT development and what added value can be attributed to creativity. Therefore, a mixed-methods study was conducted on primary school pupils aged 10 to 13 using FL-Studio Mobile^© music-producing software. Quantitative data were obtained using a pre-test–post-test assessment administered via a validated Computational Thinking Test (CTt). Qualitative data were obtained by conducting interviews to ascertain identifiable effects on CT sub-characteristics to determine the influence of creativity and creative thinking and children’s perceptions in this regard. Our results indicate that applying music-making software has measurable effects on CT development, particularly with respect to invoking and using auditory modalities. Notable findings were identified on the CT sub-characteristics “loops”, “conditionals”, “functions”, “nesting”, and “CT tasks required”. Our study shows that producing music using technology stimulates creativity, which seems to be an important parameter for CT development. Differences between girls and boys were observable. Further research on the interaction between CT and creativity, combining different modalities, is recommended. Full article

Offshore oil field loose sandstone reservoirs have high permeability. However, during the water injection process, water injection blockage occurs, causing an increase in injection pressure, making it impossible to continue injecting water on site. Current research mainly focuses on the factors causing water injection blockage, with less attention given to the blockage locations and the pressure increase caused by water injection. There is a lack of research on the change in the law of injection capacity. This paper establishes a simulation experiment for water injection blockage that can accommodate both homogeneous and heterogeneous cores. The experimental core is 1 m long and capable of simulating the blockage conditions in the near-well zone during water injection, thereby analyzing the core blockage position and blockage pressure. The study clarifies the influence of water quality indicators, heterogeneity, and core length on the blockage patterns in reservoirs during water injection. The research findings are as follows: I. The reservoir blockage samples were characterized using scanning electron microscopy (SEM), casting thin sections, and X-ray diffraction (XRD) analysis. The results indicate that the main factors causing blockage are clay, silt, and fine particulate suspensions, with the fine particles mainly consisting of hydrated silicates and alkali metal oxides. The primary cause of blockage in loose sandstone is identified as the mechanism of migration and accumulation of clay, fine rock particles, and suspended matter in the injected water. II. By monitoring pressure and permeability changes in the core flooding experiments, the impact of reservoir heterogeneity on water injection capacity was evaluated. The evaluation results show that the blockage locations and lengths in heterogeneous cores are twice those in homogeneous cores. III. For heterogeneous reservoirs, if the initial permeability at the inlet is lower than in other segments of the core, significant blockage resistance occurs, with the final resistance being 1.27 times that of homogeneous cores. If the initial permeability at the inlet is higher than in other parts, the final blockage resistance is close to that of homogeneous cores. This study provides theoretical support for the analysis of blockage locations and pressures in loose sandstone water injection and offers technical support for the design of unplugging ranges and pressures after blockage in heterogeneous formations. At the same time, it provides a theoretical basis for selecting the direction of acidizing after blockage occurs in loose sandstone. Full article

During the hydraulic fracturing process of coalbed methane (CBM) reservoirs, significant amounts of secondary coal fines are generated due to proppant grinding and crack propagation, which migrate with the fracturing fluid into surrounding fracture systems. To investigate whether coal fines can form plugs to reduce fluid leak-off during the hydraulic fracturing stage, we conducted physical simulation experiments on coal seam plugging and unplugging to demonstrate that coal fines indeed contribute to reducing fluid leak-off during hydraulic fracturing. We also explored the plugging mechanisms of coal fines under different concentrations and particle sizes in fracturing fluids, and revealed the damage law of coal fines of temporary plugging on reservoir permeability. Research results indicate the leak-off volume of fracturing fluids containing coal fines is lower than an order without coal fines, demonstrating a significant effect of coal fines in decreasing fluid leak-off. The temporary plugging rate of coal fines increases with higher concentrations and decreases with larger particle sizes, achieving rates exceeding 90%. The high temporary plugging effect of coal fines results from the superposition of internal and external filter cakes. Under conditions of small particle size and high concentration, the damage to fractures during the fine return process is minimized. Considering the potential damage of coal fines to propping fractures and wellbore, the concentration of coal fines in fracturing fluids should be kept relatively low while ensuring a high temporary plugging effect. Overall, these findings provide crucial insights into optimizing the temporary plugging performance of coal fines during the hydraulic fracturing stage and controlling their behavior during the fracturing fluid flow-back stage, thereby enhancing reservoir fracturing effectiveness and improving CBM production rates. Full article

Computational thinking is recognized as a critical competency in contemporary education, preparing individuals to tackle complex challenges in a digitally pervasive world. In this quasi-experimental design study with pretest and post-test measures, the possibility of developing computational thinking from the field of didactics of mathematics in higher education students was investigated. This was performed via a problem-based learning (PBL) methodology using problem solving in the experimental group or, alternatively, focused on the analysis of solved problems in the control group. After the intervention, the control group experienced a statistically significant improvement in the scores obtained in the post-test measure. Thus, PBL and problem solving did not lead to an improvement in the students’ computational thinking, whereas the analysis of solved problems approach did. Therefore, the results suggested the potential benefits of this latter methodology for teaching computational thinking. Full article