Prediction of Electron Beam Welding Penetration Depth Using Machine Learning-Enhanced Computational Fluid Dynamics Modelling.

The necessity for precise prediction of penetration depth in the context of electron beam welding (EBW) cannot be overstated. Traditional statistical methodologies, including regression analysis and neural networks, often necessitate a considerable investment of both time and financial resources to produce results that meet acceptable standards. To address these challenges, this study introduces a novel approach for predicting EBW penetration depth that synergistically combines computational fluid dynamics (CFD) modelling with artificial neural networks (ANN). The CFD modelling technique was proven to be highly effective, yielding predictions with an average absolute percentage deviation of around 8%. This level of accuracy is consistent across a linear electron beam (EB) power range spanning from 86 J/mm to 324 J/mm. One of the most compelling advantages of this integrated approach is its efficiency. By leveraging the capabilities of CFD and ANN, the need for extensive and costly preliminary testing is effectively eliminated, thereby reducing both the time and financial outlay typically associated with such predictive modelling. Furthermore, the versatility of this approach is demonstrated by its adaptability to other types of EB machines, made possible through the application of the beam characterisation method outlined in the research. With the implementation of the models introduced in this study, practitioners can exert effective control over the quality of EBW welds. This is achieved by fine-tuning key variables, including but not limited to the beam power, beam radius, and the speed of travel during the welding process.

Automated Interlayer Wall Height Compensation for Wire Based Directed Energy Deposition Additive Manufacturing.

Part quality monitoring and control in wire-based directed energy deposition additive manufacturing (w-DEDAM) processes has been garnering continuous interest from both the academic and industrial sectors. However, maintaining a consistent layer height and ensuring that the wall height aligns closely with the design, as depicted in computer-aided design (CAD) models, pose significant challenges. These challenges arise due to the uncertainties associated with the manufacturing process and the working environment, particularly with extended processing times. To achieve these goals in an industrial scenario, the deposition geometry must be measured with precision and efficiency throughout the part-building process. Moreover, it is essential to comprehend the changes in the interlayer deposition height based on various process parameters. This paper first examines the behaviour of interlayer deposition height when process parameters change within different wall regions, with a particular focus on the transition areas. In addition, this paper explores the potential of geometry monitoring information in implementing interlayer wall height compensation during w-DEDAM part-building. The in-process layer height was monitored using a coherent range-resolved interferometry (RRI) sensor, and the accuracy and efficiency of this measurement were carefully studied. Leveraging this information and understanding of deposition geometry, the control points of the process parameters were identified. Subsequently, appropriate and varied process parameters were applied to each wall region to gradually compensate for wall height. The wall height discrepancies were generally compensated for in two to three layers.

Aptamer-modified atomically precise gold nanoclusters as targeted nanozymes to scavenge reactive oxygen species in white adipocytes.

Oxidative stress caused by excessive reactive oxygen species (ROS) leads to the dysfunction of white adipocytes and white fat, and also promotes triglyceride storage by inhibiting the respiration of adipocytes directly. Nanozymes, as a new generation of artificial enzymes, have exhibited attractive potential in scavenging ROS and treatment of ROS-related diseases. Herein, aptamer-modified atomically precise gold Au25nanoclusters (Apt-Au25NCs), are employed as targeted nanozymes to scavenge ROS in white adipocytes. Our results show that Apt-Au25NCs have high targeting capability toward white adipocytes with low cytotoxicity. Furthermore, Apt-Au25NCs show high superoxide dismutase (SOD)-like and catalase (CAT)-like activity in a concentration-dependent manner, and also good thermal and pH stability compared with natural SOD and CAT. Finally, the efficiency of ROS scavenging by Apt-Au25NCs in white adipocytes is evaluated. This work demonstrates that Apt-Au25NCs, as targeted nanozymes, are efficient in scavenging ROS in white adipocytes, exhibiting promising potential for the treatment of obesity and related diseases.

Aptamer-functionalized AuNCs nanogel for targeted delivery of docosahexaenoic acid to induce browning of white adipocytes.

Obesity, as a global public health concern, causes a series of metabolic disorders and other diseases. Browning of white fat (white adipocytes transforming to beige adipocytes) offers an attractive approach for obesity treatment. In the present study, aptamer-functionalized nanogel of gold nanoclusters (AuNCs), termed Apt-NG, was developed as the targeted delivery vehicle of browning agent docosahexaenoic acid (DHA). Apt-NG has multiple advantages, including nanoscale size, strong autofluorescence, low toxicity, and excellent targeting capability to white adipocytes. After treatment with DHA@Apt-NG, the morphology of lipid droplets changed evidently; meanwhile the triglyceride level decreased while the mitochondrial activity increased. The DHA@Apt-NG treatment effectively up-regulated the mRNA expression levels of Ucp1, Pgc-1α, Pparg, and Prdm16, which play important roles in browning of white adipocytes. This study provides a feasible strategy to achieve efficient browning of white adipocytes based on targeted delivery nanosystems, inspiring a new idea for obesity treatment.

Transforming Industrial Manipulators via Kinesthetic Guidance for Automated Inspection of Complex Geometries.

The increased demand for cost-efficient manufacturing and metrology inspection solutions for complex-shaped components in High-Value Manufacturing (HVM) sectors requires increased production throughput and precision. This drives the integration of automated robotic solutions. However, the current manipulators utilizing traditional programming approaches demand specialized robotic programming knowledge and make it challenging to generate complex paths and adapt easily to unique specifications per component, resulting in an inflexible and cumbersome teaching process. Therefore, this body of work proposes a novel software system to realize kinesthetic guidance for path planning in real-time intervals at 250 Hz, utilizing an external off-the-shelf force-torque (FT) sensor. The proposed work is demonstrated on a 500 mm2 near-net-shaped Wire-Arc Additive Manufacturing (WAAM) complex component with embedded defects by teaching the inspection path for defect detection with a standard industrial robotic manipulator in a collaborative fashion and adaptively generating the kinematics resulting in the uniform coupling of ultrasound inspection. The utilized method proves superior in performance and speed, accelerating the programming time using online and offline approaches by an estimate of 88% to 98%. The proposed work is a unique development, retrofitting current industrial manipulators into collaborative entities, securing human job resources, and achieving flexible production.

Collaborative Robotic Wire + Arc Additive Manufacture and Sensor-Enabled In-Process Ultrasonic Non-Destructive Evaluation.

The demand for cost-efficient manufacturing of complex metal components has driven research for metal Additive Manufacturing (AM) such as Wire + Arc Additive Manufacturing (WAAM). WAAM enables automated, time- and material-efficient manufacturing of metal parts. To strengthen these benefits, the demand for robotically deployed in-process Non-Destructive Evaluation (NDE) has risen, aiming to replace current manually deployed inspection techniques after completion of the part. This work presents a synchronized multi-robot WAAM and NDE cell aiming to achieve (1) defect detection in-process, (2) enable possible in-process repair and (3) prevent costly scrappage or rework of completed defective builds. The deployment of the NDE during a deposition process is achieved through real-time position control of robots based on sensor input. A novel high-temperature capable, dry-coupled phased array ultrasound transducer (PAUT) roller-probe device is used for the NDE inspection. The dry-coupled sensor is tailored for coupling with an as-built high-temperature WAAM surface at an applied force and speed. The demonstration of the novel ultrasound in-process defect detection approach, presented in this paper, was performed on a titanium WAAM straight sample containing an intentionally embedded tungsten tube reflectors with an internal diameter of 1.0 mm. The ultrasound data were acquired after a pre-specified layer, in-process, employing the Full Matrix Capture (FMC) technique for subsequent post-processing using the adaptive Total Focusing Method (TFM) imaging algorithm assisted by a surface reconstruction algorithm based on the Synthetic Aperture Focusing Technique (SAFT). The presented results show a sufficient signal-to-noise ratio. Therefore, a potential for early defect detection is achieved, directly strengthening the benefits of the AM process by enabling a possible in-process repair.

Browning of white adipocytes by gold nanocluster mediated electromagnetic induction heating hyperthermia.

Browning of white adipose tissue (WAT) is becoming an attractive therapeutic target for obesity. Great efforts have been made to develop effective approaches to induce browning. Unfortunately, the current methods suffer from a series of disadvantages, such as low efficiency, unsatisfactory stability, and side effects. Herein, we report a new approach to induce browning of 3T3-L1 white adipocytes based on electromagnetic induction heating (EIH) hyperthermia. In particular, adipocyte-targeting aptamer modified gold nanoclusters (Apt-AuNCs) were employed as the mediators of EIH. Apt-AuNCs had good biocompatibility and excellent targeting performance with white adipocytes. After Apt-AuNCs/EIH treatment, adipocytes with characteristic multilocular and small lipid droplets increased, and the content of triglycerides reduced effectively. Apt-AuNCs/EIH treatment also significantly increased the mitochondrial activity in adipocytes. Meanwhile, the mRNA levels of key genes that are involved in browning, for example UCP1, PRDM16, PPARγ, and PGC-1α, were upregulated. Finally, the induction mechanism of Apt-AuNCs/EIH on browning of white adipocytes was explained by the synergistic effects of EIH hyperthermia and pharmacological action of AuNCs. To the best of our knowledge, this is the first attempt on induction of browning by metal nanocluster-mediated EIH hyperthermia, thus providing an interesting and efficient channel for obesity treatment.