Laser powder bed fusion of Ti-6Al-2Sn-4Zr-6Mo alloy and properties prediction using deep learning approaches

Ti-6Al-2Sn-4Zr-6Mo is one of the most important titanium alloys characterised by its high strength, fatigue, and toughness properties, making it a popular material for aerospace and biomedical applications. However, no studies have been reported on processing this alloy using laser powder bed fusion. In this paper, a deep learning neural network (DLNN) was introduced to rationalise and predict the densification and hardness due to Laser Powder Bed Fusion of Ti-6Al-2Sn-4Zr-6Mo alloy. The process optimisation results showed that near-full densification is achieved in Ti-6Al-2Sn-4Zr-6Mo alloy samples fabricated using an energy density of 77–113 J/mm3. Furthermore, the hardness of the builds was found to increase with increasing the laser energy density. Porosity and the hardness measurements were found to be sensitive to the island size, especially at high-energy-density. Hot isostatic pressing (HIP) was able to eliminate the porosity, increase the hardness, and achieve the desirable α and β phases. The developed model was validated and used to produce process maps. The trained deep learning neural network model showed the highest accuracy with a mean percentage error of 3% and 0.2% for the porosity and hardness. The results showed that deep learning neural networks could be an efficient tool for predicting materials properties using small data

Regulatory natural killer cell expression in atopic childhood asthma

Introduction: Different subsets of natural killer (NK) cells were found to play a role in pathogenesis of allergy. We sought to investigate the expression of regulatory NK cells (CD56+CD16+CD158+) in atopic children with bronchial asthma in order to outline the value of these cells as biomarkers of disease severity and/or control.Methods: A cross sectional controlled study was carried out in the Pediatric Allergy and Immunology Unit, Ain Shams University. The study included 45 atopic children [mean age(SD)= (2.9) years] with bronchial asthma (BA) and/or allergic rhinitis (AR)as well as 40 healthy matched controls. Enrolled subjects underwent complete blood counting and flow cytometric measurement of NK cell (CD16+ CD56+) and regulatory NK cells (CD16+CD56+CD158+).Results: Patients had significantly higher regulatory NK cell percentages [mean (SD)= 41 (52) %] than controls [mean (SD)=15 (7.1)]; p≤0.001. Regulatory NK cell counts and percentages did not vary with the concomitant presence of AR or the degree of asthma control. Regulatory NK cell counts tended to be higher in children with moderate/severe BA compared to those with mild asthma but the difference did not reach statistical significance (U= -1.8, p=0.06). NK cell counts [mean (SD)= 159 (164) cells/μl] and percentages [mean (SD)= 3.7 (3.2) %] were comparable among patients and controls and did not vary with the presence of AR (p= 0.51, 0.95) or with the degree of asthma control. NK cells absolute counts and percentages tended to be higher among patients with moderate/severe compared to mild asthma but the difference did not reach statistical significance.Conclusions: Regulatory NK cells seem to be increased in childhood asthma. We recommend wider scale prospective studies on steroid-naïve subjects involving measurement of cytokines that are secreted by different types of NK cells.Keywords: Natural killer, regulatory, asthma, children, allerg

A novel vision-based multi-functional sensor for normality and position measurements in precise robotic manufacturing

Cobots play an essential role in the fourth industrial revolution and the automation of complex manufacturing processes. However, cobots still face challenges in achieving high precision, which obstructs their usage in precise applications such as the aerospace industry. Nonetheless, advances in perception systems unlock new cobot manufacturing capabilities. This paper presents a novel multi-functional sensor that combines visual and tactile feedback using a single optical sensor, featuring a moving gate mechanism. This work also marks the first integration of Vision-Based Tactile Sensing (VBTS) into a robotic machining end-effector. The sensor provides vision-based tactile perception capabilities for precise normality control and exteroceptive perception for robot localization and positioning. Its performance is experimentally demonstrated in a precise robotic deburring application, where the sensor achieves the high-precision requirements of the aerospace industry with a mean normality error of 0.13° and a mean positioning error of 0.2 mm. These results open a new paradigm for using vision-based sensing for precise robotic manufacturing, which surpasses conventional approaches in terms of precision, weight, size, and cost-effectiveness

Three-dimensional microstructured lattices for oil sensing

Monitoring of environmental contamination, including oil pollution, is important to protect marine ecosystems. A wide range of sensors are used in the petroleum industry to measure various parameters, such as viscosity, pressure, and flow. Here, we create an optical lattice mesh structure that can be used as an oil sensor integrated with optical fiber probing. The principle of operation of the sensor was based on light scattering, where the tested medium acted as a diffuser. Three different mesh-patterned structures were analyzed by optical imaging, light transmission, and scattering in the presence of supercut, diesel, and stroke oil types. The meshes were used as a medium for different types of oils, and the optical diffusion and transmission were studied in the visible spectrum. Angle-resolved measurements were carried out to characterize the light scattering behavior from the mesh structures. Different types of oils were identified on the basis of the optical behavior of the lattice structure. The fabricated mesh structures can be used as a low-cost measurement device in oil sensing

Chip formation and orthogonal cutting optimisation of unidirectional carbon fibre composites

This study presents a thorough experimental investigation utilising the design of experiments and analysis of variance (ANOVA) to examine the impact of machining process parameters on chip formation mechanisms, machining forces, workpiece surface integrity, and damage resulting from the orthogonal cutting of unidirectional CFRP. The study identified the mechanisms behind chip formation and found it to significantly impact the workpiece orientation of fibre and the tool’s cutting angle, resulting in increased fibre bounceback at larger fibre orientation angles and when using smaller rake angle tools. Increasing the depth of cut and fibre orientation angle results in an increased damage depth, while using higher rake angles reduces it. An analytical model based on response surface analysis for predicting machining forces, damage, surface roughness, and bounceback was also developed. The ANOVA results indicate that fibre orientation is the most significant factor in machining CFRP, while cutting speed is insignificant. Increasing fibre orientation angle and depth leads to deeper damage, while larger tool rake angles re-duce damage. Machining workpieces with 0° fibre orientation angle results in the least subsurface damage, and surface roughness is unaffected by the tool rake angle for fibre orientations between 0° to 90° but worsens for angles greater than 90°. Optimisation of cutting parameters were subsequently optimised to improve machined workpiece surface quality and reduce forces. The experimental results showed that negative rake angle and cutting at moderately low speeds (366 mm/min) is the optimal conditions for machining laminates with a fibre angle of θ = 45°. On the other hand, for composite materials with fibre angles of θ = 90° and θ = 135°, it is recommended to use a high positive rake angle and cutting speeds

Small Molecules Targeting Human UDP-GlcNAc 2-Epimerase

Uridine diphosphate N-acetylglucosamine 2-epimerase (GNE) is a key enzyme in the sialic acid biosynthesis pathway. Sialic acids are primarily terminal carbohydrates on glycans and play fundamental roles in health and disease. In search of effective GNE inhibitors not based on a carbohydrate scaffold, we performed a high-throughput screening campaign of 68,640 drug-like small molecules against recombinant GNE using a UDP detection assay. We validated nine of the primary actives with an orthogonal real-time NMR assay and verified their IC50 values in the low micromolar to nanomolar range manually. Stability and solubility studies revealed three compounds for further evaluation. Thermal shift assays, analytical size exclusion, and interferometric scattering microscopy demonstrated that the GNE inhibitors acted on the oligomeric state of the protein. Finally, hydrogen-deuterium exchange mass spectrometry (HDX-MS) revealed which sections of GNE were shifted upon the addition of the inhibitors. In summary, we have identified three small molecules as GNE inhibitors with high potency in vitro, which serve as promising candidates to modulate sialic acid biosynthesis in more complex systems

Ecdysozoan mitogenomics: evidence for a common origin of the legged invertebrates, the Panarthropoda

Ecdysozoa is the recently recognized clade of molting animals that comprises the vast majority of extant animal species and the most important invertebrate model organisms—the fruit fly and the nematode worm. Evolutionary relationships within the ecdysozoans remain, however, unresolved, impairing the correct interpretation of comparative genomic studies. In particular, the affinities of the three Panarthropoda phyla (Arthropoda, Onychophora, and Tardigrada) and the position of Myriapoda within Arthropoda (Mandibulata vs. Myriochelata hypothesis) are among the most contentious issues in animal phylogenetics. To elucidate these relationships, we have determined and analyzed complete or nearly complete mitochondrial genome sequences of two Tardigrada, Hypsibius dujardini and Thulinia sp. (the first genomes to date for this phylum); one Priapulida, Halicryptus spinulosus; and two Onychophora, Peripatoides sp. and Epiperipatus biolleyi; and a partial mitochondrial genome sequence of the Onychophora Euperipatoides kanagrensis. Tardigrada mitochondrial genomes resemble those of the arthropods in term of the gene order and strand asymmetry, whereas Onychophora genomes are characterized by numerous gene order rearrangements and strand asymmetry variations. In addition, Onychophora genomes are extremely enriched in A and T nucleotides, whereas Priapulida and Tardigrada are more balanced. Phylogenetic analyses based on concatenated amino acid coding sequences support a monophyletic origin of the Ecdysozoa and the position of Priapulida as the sister group of a monophyletic Panarthropoda (Tardigrada plus Onychophora plus Arthropoda). The position of Tardigrada is more problematic, most likely because of long branch attraction (LBA). However, experiments designed to reduce LBA suggest that the most likely placement of Tardigrada is as a sister group of Onychophora. The same analyses also recover monophyly of traditionally recognized arthropod lineages such as Arachnida and of the highly debated clade Mandibulata