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Turbulence without Walls: Whither the Zeroth Law of Turbulence?
No full textExperimental and numerical studies of incompressible turbulence suggest that the mean dissipation rate of kinetic energy remains constant as the Reynolds number tends to infinity (or the nondimensional viscosity tends to zero). This anomalous behavior is central to many theories of high-Reynolds-number turbulence and has been termed the “zeroth law” for this reason. Here, we report a sequence of direct numerical simulations of incompressible Navier-Stokes in a box with periodic boundary conditions, which indicate the likelihood that the anomaly vanishes at a rate that agrees with the scaling of third moment of absolute velocity increments. Our results suggest that turbulence without solid boundaries or walls may not develop strong enough singularities to sustain the strict version of the zeroth law
Correction to: Georgia and Florida Logging Businesses Persevere Through Pandemic, Rising Costs, and Uncertainty (Forest Science, (2024), 70, 1, (47-56), 10.1093/forsci/fxad050)
No full textIn this article Rafia Rahman at affiliation ‘Michigan Technological University, 1400 Townsend Dr., Houghton, MI 49931, USA’ was missing from the author list
Characterizing Surface Waviness of Aluminum Alloy: An Approach to Minimize Post-Processing in Wire Arc Additive Manufacturing (WAAM) Production
No full textWire Arc Additive Manufacturing (WAAM) offers high deposition rates and cost-effective production of large metal components but suffers from poor surface quality, particularly surface waviness, which increases post-processing requirements and limits industrial adoption. Since waviness directly impacts structural integrity, resource efficiency, and industrial applicability, understanding how process parameters govern this feature is critical for reducing post-processing requirement. This study systematically investigated the influence of voltage, travel speed, and wire feed speed on surface waviness in aluminum alloy walls fabricated by WAAM. A two-level factorial design with 16 experiments was conducted, and surface waviness was quantified using height gauge measurements relative to the expected bead height. Statistical analyses, including ANOVA and multiple linear regression, were applied to evaluate parameter significance. The results revealed that wire feed speed was the most influential parameter, showing a strong positive correlation with waviness due to excess material deposition. Voltage exhibited a weaker, stabilizing effect, with higher values marginally reducing waviness through improved arc stability, while travel speed had negligible influence within the studied range. The regression model achieved an (Formula presented.) 0.389, with validation tests indicating reasonable predictive accuracy. These findings demonstrate that controlling wire feed speed is critical for minimizing waviness, while higher voltage may serve as a secondary stabilizing factor. The study was limited to surface waviness however, future work should consider the role of thermal accumulation, inter-pass temperature, and external disturbances on surface stability. Such insights could enable adaptive parameter control strategies to further reduce post-processing needs and enhance the industrial viability of WAAM
“She’s Everything”: Mattel’s Re-Branded Barbie Vlogger as Can-Do Girl Influencer
No full textIn the Barbie Vlogs series on YouTube, Barbie is a teen influencer with a modern “can-do girl” attitude. She is competent, driven, and embodies confidence and empowerment—she codes, sings, DIYs, and expresses herself through other interests. In her vlogs, Barbie performs aesthetic labor commonly seen in feminine influencers, such as self-expression, authenticity, and vulnerability. Through these Vlogs, Mattel has re-envisioned Barbie to be a more empowering figure for young girls through her limitless capacity, and rebranded Barbie to perform authenticity while speaking directly to young girls and encouraging a specific performance of teen girlhood online that includes aesthetic labor through self-disclosure and self-expression. Based on a feminist content analysis of the Vlogs, this chapter argues that Barbie performs girls’ culture by filming content in her bedroom with the goal of emotionally connecting with friends and viewers and reveals that the ideal, adult-approved contemporary girl culture is competence rather than leisure. Barbie performs aesthetic labor in her leisure time by exuding both inner and outer beauty through her continued dedication to fashion and hobbies (in place of careers) and newfound goal of self-expression. Barbie’s self-disclosure and self-expression practices are reflective of the existing surveillance culture of girls, as well as the adult-mediated empowerment discourse surrounding girlhood. Barbie Vlogger is a corporate influencer directed at little girls, showcasing ideal teen girlhood and limitless capacity without the stereotypical boy-craziness, hysteria, or cattiness, visually influencing girls in how to be an ideal teen girl, too
Mine Planning with Variable Price Input: A Case of Using Mine Planning Software
No full textThe success of a mining project heavily dependent on the accuracy of input parameters used during the mine planning process, particularly commodity price that determines the proportion of ore and waste in the deposit. Conventional mine planning tools typically employ the Lerchs-Grossman (LG) algorithm, which takes fixed commodity price as input to generate ultimate pit limit and pushbacks. This article used an enhanced approach to incorporate commodity prices volatility into the LG algorithm. Initially, gold prices were predicted using the Autoregressive Distributed Lag (ARDL) which was deemed suitable for the chosen commodity from the previous studies. These prices were then integrated into the LG mine planning algorithm on an annual basis to estimate the impact of price volatility on net present value (NPV) when commodity prices are under both upward and downward price trends. Finally, a comparison was made between constant price and variable price approaches using NPV. The results showed that the constant price model underestimated the NPV by approximately 35%, whereas the ARDL-based forecast led to a 27% overestimation relative to the actual price. Conversely, during periods of price decline, the deterministic price model overestimated NPV by nearly 30%, while the ARDL approach yielded an underestimation of only 4%. The results confirm that incorporating price volatility into the mine planning software that employing LG mine planning algorithm is possible and also yields NPV estimates that more close to reality compared to those derived from a constant price assumption
Recent Advances and Future Perspectives in Biomedical Textiles: Smart Polymers, Nanotechnology, and Clinical Applications
No full textBiomedical textiles are one of the rapidly growing technical textiles, driven by advancements in fiber and polymer research, as well as innovations in creating new textile structures that offer innovative healthcare solutions, ranging from wound dressings to implantable devices. This article provides a comprehensive overview of recent advances in biomedical textiles, including the use of advanced polymers (both natural and synthetic), fabrication techniques, applications, and current limitations. Additionally, potential directions for future research are explored to guide the development of the next generation of medical textiles. A bibliometric analysis 2012–2025 reveals rapid growth in publications, peaking in 2022–2023, with notable research trends in innovative polymeric materials, nanotechnology, and regenerative medicine. The use of both natural and artificial fibers, along with smart textiles and advancements made possible by nanotechnology, has led to significant improvements in combating bacteria and delivering drugs. However, gaps persist in biodegradability and clinical translation. The results of this paper benefit researchers, physicians, and business professionals engaged in this dynamic field, helping them understand current trends and emerging opportunities in the field of biomedical textiles
Emerging tools in plant genome editing
No full textPlant genome editing has undergone a transformative shift with the advent of advanced molecular tools, offering unprecedented levels of precision, flexibility and efficiency in modifying genetic material. While classical site-directed nucleases such as ZFNs, TALENs and CRISPR-Cas9 have revolutionized genome engineering by enabling targeted mutagenesis and gene knockouts, the landscape is now rapidly evolving with the emergence of novel systems that go beyond the conventional double strand break (DSB)-mediated approaches. Advanced and recent tools include LEAPER, SATI, RESTORE, RESCUE, ARCUT, SPARDA, helicase-based approaches like HACE and Type IV-A CRISPR system, and transposon-based techniques like TATSI and piggyBac. These tools unlock previously inaccessible avenues of genome and transcriptome modulation. Some of these technologies allow DSB-free editing of DNA, precise base substitutions and RNA editing without altering the genomic DNA, a significant advancement for regulatory approval and for species with complex genomes or limited regeneration capacity. While LEAPER, RESCUE and RESTORE are the new advents in the RNA editing tool, SATI allows DSB-free approach for DNA editing, ARCUT offers less off-target and cleaner DNA repairs and Type IV-A CRISPR system induces gene silencing rather than editing. The transposon-based approaches include TATSI, piggyBac and TnpB, and helicases are used in HACE and Type IV-A CRISPR system. The prokaryotic Argonaute protein is used in SPARDA tool as an endonuclease to edit DNA. The transient and reversible nature of RNA editing tools such as RESTORE and LEAPER introduces a new layer of epigenetics-like control in plant systems, which could be harnessed for tissue-specific and environmentally-responsive trait expression. Simultaneously, innovations like ARCUT and SPARDA utilize chemically-guided editing, minimizing reliance on biological nucleases and reducing off-target risks. Their modularity and programmability are enabling gene function studies, synthetic pathway designs and targeted trait stacking. These advances represent a novel synthesis of genome engineering and systems biology, positioning plant genome editing not just as a tool of modification but as a platform for designing adaptive and intelligent crops, tailored to future environmental and nutritional challenges. Although, many of these recent tools remain to be applied on plant systems, they are proven to be effective elsewhere and hold a great potential to be effective in creating climate-resilient crops
Industrial IoT Automation, Predictive Maintenance, and Smart Manufacturing
No full textThe (IIoT) transformative force is modern driving an unprecedented wave of digitalization and connectivity across sectors of physical machinery with enabled actuators, advanced data analytics, resulting in monitor, exchange, analyze systems, humans, IIoT empowers industries to achieve greater operational efficiency, pre-dictive maintenance, improved product quality, and enhanced safety. Its impact is particularly visible in manufacturing, energy, transportation, healthcare, and supply chain management-industries that historically relied on manual operations and reactive maintenance are now leveraging IIoT to shift toward data- driven, proactive models. One of the most significant contributions of IIoT is in operational efficiency. Through connected devices and smart sensors, organizations gain granular, realtime visibility into every aspect of their operations. Machines can autonomously report performance metrics, detect anomalies, and suggest optimizations, leading to reduced downtime and better resource utilization
Computational Hemodynamic Analysis of Pre-treatment Type A and Type B Aortic Dissections
No full textAortic dissection is a serious vascular condition typically triggered by a tear in the inner layer of the aortic wall. The widespread occurrence of the disease emphasizes the need for standardized treatment and surgical guidelines. There have been improved strategies for surgical intervention and treatment of aortic dissection over the years. However, there remains a gap in monitoring of dissection growth specifically in the pre-surgical period of the disease. Hemodynamic studies based on CFD have shown insightful results regarding false lumen dilatation, aneurysmal growth and thrombus formation in post surgical and endovascular repaired cases. Also, the application of different outlet boundary conditions, in the absence of patient-specific data, can lead to substantial variations in flow dynamics in CFD-based analyses of aortic dissection (AD). In this study, hemodynamic parameters including luminal pressure difference (LPD), time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), relative residence time (RRT), endothelial cell activation potential (ECAP), and the number of combined vortex cores in the false lumen were evaluated under two simulation settings: zero-pressure outlets and pressure waveform outlets. All cases represented pre-treatment stages with variable disease onset times. Morphological characteristics such as maximum false lumen diameter, false lumen volume, and primary and re-entry tear areas were also quantified. Although the parameters did not differ markedly between type A and type B dissections, considerable variations
in flow and pressure parameters were observed between the two boundary condition groups. The relative differences in several key parameters between the two conditions exceeded 100% in most cases (LPD: 144.27%, number of vortex cores: 132.02%, TAWSS: 105.74%). In condition 1 (zero-pressure outlets), the absence of downstream vascular impedance resulted in unrealistically low pressure difference values, whereas condition 2 (pressure waveform outlets) produced higher and more physiologically representative pressures due to the inclusion of pulsatile effects. The altered inflow behavior in condition 2 also led to an increased number of vortex cores in larger false lumens particularly observed in partially thrombosed cases. Additionally, TAWSS values were consistently low across both conditions, suggesting a potential contribution to false lumen thrombus formation and progressive dilatation over time. Overall, the use of zero-pressure outlet conditions can significantly distort flow dynamics and yield hemodynamically unrealistic results in aortic dissection simulations