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Article

28 August 2024

Metallurgical Characteristics of 316L Stainless Steel by Laser Additive Manufacturing

Laser Additive Manufacturing (LAM), an avant-garde technology in manufacturing, harnesses the precision of laser energy to fabricate intricate parts through the meticulous process of melting and subsequently depositing layers of metal powders. Among the esteemed materials employed, 316L stainless steel (316L SS) stands out for its unparalleled corrosion resistance, exceptional high-temperature tolerance, and remarkable creep strength, making it a ubiquitous choice in the aerospace, medical, and nuclear power sectors. LAM has distinguished itself in the fabrication of intricate 316L SS components, yet enhancing the metallurgical bonding strength within these structures remains a pivotal area of ongoing research. This research endeavor delves into the intricate microstructure and mechanical properties that characterize the interface between the LAM-produced 316L SS cladding layer and its substrate, further investigating how varying laser energy densities (E) subtly influence these properties within the additive manufactured components. Remarkably, the interface region exhibits a tensile strength of 615.1 MPa, surpassing that of both the deposited layer and the substrate by 5.4% and 7.4% respectively, underscoring a robust bond between the two layers. This investigation not only sheds light on the unique process capabilities and performance merits of LAM in crafting 316L SS cladding layers but also pioneers novel approaches and conceptual frameworks for bolstering the metallurgical bonding strength of this esteemed material. As such, it constitutes a treasure trove of insights for subsequent research endeavors and practical applications across related disciplines.

Keywords: Laser additive manufacturing; Metallurgical bonding strength; Microstructure; Mechanical properties; 316L stainless steel

Article

28 August 2024

Overcoming SME Legal and Regulatory Challenges and Fostering Sustainable Collaboration and 7PS Engineering in the Digital Age through Integrating the X.0 Wave Theory & SME 5.0 Concept

Technological innovations, education, business and society change quickly and often unpredictably. The fusion of artificial intelligence (AI), machine learning, augmented reality (AR), virtual reality (VR) and augmented reality (XR) opens a new era in which work, production, communication and thought processes are massively transformed. In this context, the challenge arises: How can small and medium-sized enterprises (SMEs) adapt to this accelerated change? This study highlights a path forward and introduces the concept of “SME 5.0” or “Hybrid SME” or “SME of Tomorrow” as a comprehensive solution to address the complexities of the digital age. In this integrated exploration of the X.0 Wave Theory and SME 5.0 Concept, the framework for human civilization’s evolution and technological shifts converges with a practical roadmap for small and medium-sized enterprises (SMEs) navigating the dynamic digital landscape. Acknowledging transformative waves in technology, economics, and societal structures within the X.0 Wave Theory, the study accentuates the ongoing nature of these shifts. It advocates for a long-term perspective, urging policymakers and industry leaders to consider potential future scenarios to devise strategies fostering innovation, competitiveness, and privacy safeguards. Simultaneously, the study introduces SME 5.0 as a holistic solution for SMEs, aligning with the transformative success envisioned by the X.0 Wave Theory. Proposing the Seven Pillars of Sustainability (7PS) framework tailored to SMEs, the concept emphasizes digitalization and sustainable technology. The title, “Harmonizing the X.0 Wave Theory and SME 5.0 Concept”, encapsulates the synergy between theoretical underpinnings and practical solutions. The subtitle, “Fostering Sustainable Collaboration, 7PS Engineering, and Overcoming Legal Challenges in the Digital Age”, provides a glimpse into the study’s focus on practical implications, sustainability, engineering, and legal considerations for SMEs in the rapidly evolving digital era.

Keywords: SME 5.0/Hybrid SMEs or Tomorrow’s SMEs; Sustainable Collaboration; Emerging Technologies; 7PS Sustainable Engineering; Digital Age; SME Legal and Regulatory Challenges; Digitalization; AI; VR; XR; AI; SME; 7PS Model; X.0 Wave/Age theory; i-Sustainability Plus theory

Review

27 August 2024

Strongly Correlated Electrons and High Temperature Superconductivity

It is very important to clarify the mechanism of high-temperature superconductivity in strongly correlated electron systems. The mechanism of superconductivity in high temperature cuprate superconductors has been studied extensively since their discovery. We investigate the properties of correlated electron systems and mechanism of superconductivity by using the optimization quantum variational Monte Carlo method. The many-body wave function is constructed by multiplying by correlation operators of exponential type. We show that d-wave superconducting phase exists in the strongly correlated region where the on-site repulsive interaction is as large as the bandwidth or more than the bandwidth. The d-wave pairing correlation function is shown as a function of lattice sites, showing that the long-range order indeed exists.

Keywords: High-temperature superconductivity; Strongly correlated electron systems; Mechanism of superconductivity; Optimization variational Monte Carlo method; Hubbard model; Phase diagram

Review

27 August 2024

A Novel Comprehensive Program Combining Optimal Medical Treatment with Lifestyle Modification for Type 2 Diabetes

There are more and more individuals with type 2 diabetes (T2D) in the globe. It’s a huge burden of public health and a great challenge in clinical due to a high linkage with atherosclerosis, cardiovascular disease (CVD), stroke, and cancer. However, little is known about a comprehensive program of management and self-management of T2D. This article introduces briefly the current status in T2D and an updated classical standardized comprehensive program which combines optimal medical treatment (OMT) (the glucagon-like peptide-1 receptor agonists, the sodium-glucose cotransporter 2 inhibitors, and the ultralong-acting, once-daily basal insulin) with lifestyle modification, that is, intervention of RT-ABCDEFG (iRT-ABCDEFG) for control and prevention of T2D, and discusses its advantages and prospects. As an effective comprehensive program and strategy for interventions of diabetes, this program can be used as a reversible, right, and routine treatment. Several pivotal goals including less major adverse cardiocerebrovascular events (MACCE) and diabetic complications, less medical costs, longer life expectancy, lower morbidity and mortality, and higher quality of life, will be realized by consistently practicing this program due to early diagnosis, OMT, and lifestyle modification for overall prevention. All in all, since T2D highly links to CVD and cancer, as well as other MACCE, this novel iRT-ABCDEFG program is very helpful in comprehensive management and self-management of T2D and worth recommending for further application and health care of T2D due to better clinical efficacy and cost-effective relationship.

Keywords: iRT-ABCDEFG; Lifestyle; Prevention; Treatment; Type 2 diabetes

Article

26 August 2024

Delivery of Novel Replicating Vectors to Synechococcus sp. PCC 7002 Via Natural Transformation of Plasmid Multimers

In most cyanobacteria, genetic engineering efforts currently rely upon chromosomal integration; a time-consuming process due to their polyploid nature. To enhance strain construction, here we develop and characterize two novel replicating plasmids for use in Synechococcus sp. PCC 7002. Following an initial screen of plasmids comprising seven different origins of replication, two were found capable of replication: one based on the WVO1 broad host range plasmid and the other a shuttle vector derived from pCB2.4 from Synechocystis sp. PCC 6803. These were then used to construct a set of new replicating plasmids, which were shown to be both co-transformable and stably maintained in PCC 7002 at copy numbers between 716 and 0.61.4, respectively. Lastly, we demonstrate the importance of using multimeric plasmids during natural transformation of PCC 7002, with higher order multimers providing a 30-fold increase in transformation efficiency relative to monomeric plasmids. Useful considerations and methods for enhancing multimer content in plasmid samples are also presented.

Keywords: Cyanobacteria; Replicating plasmids; Synechococcus sp. PCC 7002; Plasmid multimers; Transformation

Article

22 August 2024

Erosion Resistance of BaZrO3-Y2O3 Two-Phase Crucibles against Highly Active Ti2Ni Alloys

In this paper, (100-m) BaZrO3-mY2O3 (m = 0, 20, 25, 33, 50, 100) crucibles were prepared, respectively. Then, the effect of crucible composition on the interaction between crucibles and highly active titanium alloys (Ti2Ni) was investigated. The degree of the erosion resistance of crucibles was compared before and after melting as well as the contaminated extent of the alloys. The results show that the two-phase crucibles consisting of BaZr1−xYxO3−δ and Y2O3(ZrO2), could be prepared after adding Y2O3 into the BaZrO3 crucible. As the amount of Y2O3 addition in the crucible was increased, the erosion resistance of the crucible to the alloy melt was gradually improved. The two-phase crucible with 50 wt.% Y2O3 addition exhibited the best erosion resistance with a 7 μm thick erosion layer, which was at the same level compared to the pure Y2O3 crucible (6.5 μm). However, the inclusion contaminants caused by this two-phase crucible were smaller than those of the pure Y2O3 crucible. This study provided a theoretical basis for further research on the preparation of highly stable crucibles for melting highly active titanium alloys.

Keywords: BaZrO3; Y2O3; Crucible; Ti2Ni alloys; Vacuum induction melting

Communication

22 August 2024

Mixed Matrix Membranes Produced from a Fluorinated MOF and Pebax for CO2/H2 Separation

Hydrogen (H2) emerges as a promising clean energy source, but its efficient purification from various sources needs advanced separation technologies. This study explores the use of CO2-selective membranes, especially mixed matrix membranes (MMM) incorporating KAUST-7 metal-organic framework (MOF), for hydrogen purification. The MMM was fabricated with various KAUST-7 content in a polymer matrix (Pebax 1657) and characterized via Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and gas permeation tests. The XRD analysis confirms the incorporation of KAUST-7 into the MMM, while SEM reveals a homogeneous particle distribution at low content (below 10%) but agglomeration at higher ones (above 10%). FTIR confirms good interfacial interactions between the MOF and polymer matrix. TGA results show that the MMM thermal stability slightly decreases with increasing MOF content. Gas permeation results reveal improved CO2 permeability (79%) and CO2/H2 selectivity (19%) for MMM compared to neat Pebax membranes, with an optimal performance observed at 10 wt.% KAUST-7. Beyond this threshold, the performance deteriorates, possibly due to polymer rigidity and MOF agglomeration. Overall, the study highlights the potential of KAUST-7/Pebax MMM for enhanced hydrogen purification.

Keywords: Mixed matrix membrane; Carbon dioxide; Hydrogen; Metal-organic framework; Pebax; KAUST-7; Permeability; Selectivity

Review

22 August 2024

Current Application of Modeling and Cell-Free System for Synthetic Gene Circuit Design

The desire to harness nature’s capability of precise gene expression regulation has motivated the pursuit of synthetic gene circuits. However, designing and building novel synthetic gene circuits with predictable dynamics is nontrivial. To facilitate the design, cell-free systems have emerged as an effective alternative testbed to living biological systems in characterizing and prototyping synthetic gene regulatory networks, given its relative simplicity and designability in terms of cellular contents. Meanwhile, as parameterizing and analyzing first principle-based models can shed light on the required kinetic parameter values, thus the specific regulatory components, for the desired dynamics, coupling mathematical modeling with cell-free experiments has become an effective approach in exploring novel synthetic gene circuits. In this mini-review, we provide an overview of current progress on using deterministic first principle-based mathematical modeling in conjunction with cell-free systems, in designing and characterizing novel gene circuits, as well as the standing challenges and issues with this approach.

Keywords: Cell-free system; Mathematical modeling; Gene circuits; Synthetic biology

Opinion

22 August 2024

Medical Drones for Public Health Emergency Preparedness, Response, and Resilience: Delivering Health for All

Amid a global metacrisis of health, environmental and economic challenges, medical delivery drones (or uncrewed aerial vehicles) offer a promising method to prepare for, and rapidly respond, to future emergencies. This opinion article summarizes the current medical delivery drone landscape, evidence base, and policy implications in the context of public health emergencies, such as pandemics, natural disasters, and humanitarian crises, with a particular emphasis on the region of sub-Saharan Africa. Using a multilateral, international health policy perspective, key challenges and opportunities, such as the development of sustainable funding mechanisms, robust regulatory frameworks, and capacity building, are identified.

Keywords: Medical delivery; Public health; Health policy; Global health; Digital health; Sub-Saharan Africa

Opinion

21 August 2024
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