This study investigates the fatigue degradation and crack propagation in the locking mechanism of PET bottle blow molding machines, focusing on the impact of elliptical cracks on the mechanism’s performance and longevity. The locking mechanism, which plays a vital role in securing the mold during the blow molding process, is subjected to repeated loading, making it susceptible to fatigue damage. Using a combination of finite element analysis (FEA) and experimental methodologies, we examine the stress distribution, deformation, and displacement in the mechanism under operational loads. The study identifies the most stressed component and models the behavior of an elliptical crack located at the center of this component. A stress intensity factor (K) of 3.7553 MPa.mm-0.5 is found, indicating significant risk in the crack region. Fatigue analysis using Goodman’s law predicts a service life of one million cycles with a safety factor of 2.08. These findings highlight the need for targeted design and maintenance strategies to enhance the reliability and durability of PET blow molding machines.

This paper investigates the relationship between the extended spectrum of a bounded linear operator and its group inverse. We also establish a connection between the extended spectrum of the bounded linear operator and that of its Drazin inverse. As part of our analysis, we prove the following equality: σext((BA)D) = σext((AB)D), where (BA)D and (AB)D represent the Drazin inverses of BA and AB, respectively. 2020 Mathematics Subject Classification. 35K15; 35K55; 35K65; 35B40. Key words and phrases. extended spectrum; operator group inverse; Drazin inverse.

III-V-based materials are widely used for multi-junction solar cell applications due to their large band gap, allowing them to absorb a significant amount of light and increase the output power. Among the III-V materials, AlGaAs is a promising candidate for the top cell due to its tunable band gap. However, the growth of AlGaAs often leads to the formation of DX-centers, resulting in low material quality and limiting the reported efficiencies of AlGaAs cells to mostly below 18.7%. Research in this field has primarily focused on single and multi-variable parameter sweep methods to optimize the conversion efficiency of solar cells. While effective, these techniques can be time-consuming, especially when only the final result matters and their accuracy diminishes as the number of layers in the cell increases. To address these challenges, we proposed a metaheuristic method based on Real Coded Genetic Algorithm (RCGA) to optimize the solar cell. By hybridizing MATLAB and Atlas SILVACO, we developed an efficient code. The effectiveness of the utilized modeling framework is evaluated by comparing its predictions to experimental results, revealing a strong correspondence between the two. The obtained results were compared to those achieved using conventional parameter sweep methods. Our optimized solar cell achieved an efficiency of 26.08% under the AM1.5 spectrum. The findings demonstrate that a multi-dimensional optimization using the RCGA approach, combined with the Atlas SILVACO simulator, can be effectively employed to optimize semiconductor devices, offering a more robust alternative to existing methods.

This study presents the development and validation of a hybrid cutting force prediction model for ball end milling of aluminum 7075-T6 alloy. The model combines a mechanistic approach with a specific cutting force coefficient (Ks=850 N/mm²) sourced from experimental literature. Cutting forces in the x, y, and z directions are predicted by integrating differential force components with tool geometry and machining parameters. Experimental validation was performed under dry conditions at a spindle speed of 15,000 rpm. In the x-direction, the simulated force was 162.4 N versus an experimental force of 215.4 N; in the y and z-directions, predicted values (65.2 N and 25.3 N) closely matched experimental forces (74.3 N and 28.2 N), respectively. The corresponding mean absolute errors were 18.2% (x), 4.5% (y), and 3.3% (z). The higher error in the x direction highlights limitations in modeling tangential force dynamics, while the y and z predictions align closely with experimental data. Leveraging the experimentally derived Ks, the proposed model offers a practical tool for optimizing machining processes in the aerospace sector, with potential for further refinement in tangential force modeling.

One of the main factors that adversely affect surface quality, dimensional accuracy, and geometric precision during turning processes is workpiece’s deformation. The manufacturer's optimization of the cutting process is crucial. The goal of this work is to model and optimize workpiece’s deflection using statistical analysis. The tangential and radial cutting forces were observed as a function of the cutting parameters: cutting speed (Vc in m/min), advance (f in mm/rev), cutting depth (ap in mm), workpiece hardness (HB), and tool rake angle (An) using a numerical experimental plan (DOE) based on the Taguchi L32 table and the finite element analysis (FEA) tool (Third Wave AdvantEdge). For every test, the cantilever beam equation is used to determine the workpiece's deflection, which is then examined using the statistical approach based on the controllable parameters through cutting forces and the workpiece's overhang ratio (L/d). Prediction models have been found for the quantity of interest.

The usual use of value stream mapping is studying to improve production lines that are already running. In this study, we used value stream mapping and the PDCA cycle on a production line that is still being finished and not yet operational. This work is important and unique because it uses a proactive approach to improve processes. The used method aims to create a waste-free production chain from the start. This is a big plus because it means avoiding losses with high costs and getting a very efficient production line from the start. The findings demonstrate that lean manufacturing tool (VSM) can be used on current and future production lines, and this strategy enhances production line efficiency from the outset by minimising non-value-added activities and maximising value-added activities.

The undifferentiated nasopharyngeal cancer (NPC) is a multifactorial disease mainly due to Epstein-Barr Virus (EBV) infection. The transmembrane tyrosine kinase 'EphA2' and the protease 'Furin' are implicated in the EBV entry into epithelial cells and other physiological processes. To gain insights into the association of single-nucleotide polymorphisms (SNPs) rs4702 and rs6603883 (FURIN and EPHA2 genes, respectively) with the risk and prognosis of the NPC, the genotypes of 471 individuals (228 cases and 243 controls) were assessed alongside risk cofactors (sex, tobacco, alcohol, occupation, and recurrent Ear, Nose and Throat infections) and prognosis cofactors (Tumor stage, local invasion, lymph node involvement, and metastasis) using multivariable logistic regression. We found that only the rs4702 AG/GG genotypes were statistically significantly associated with a reduced risk of cancer, both in the overall population and in men (approximately 50% reduction). The rs4702 GG genotype was also associated with a low frequency of local tumor invasion in the whole population (OR = 0.382, p = 0.017, co-dominant model, and OR = 0.409, p = 0.02, recessive model), but heterozygous women were associated with a higher lymph node involvement (OR = 3.53, p = 0.031, co-dominant model, and OR = 3.62, p = 0.02, overdominant model). The rs6603883 GG genotype was associated, in the dominant model, with distant metastasis in the whole population (OR = 2.5, p = 0.024), with advanced clinical stage in men (OR = 2.22, p = 0.034), and with advanced clinical stage and distant metastasis in patients under 49 years (OR = 3.13, p = 0.009, and OR = 5.15, p = 0.011, respectively). Additionally, men having the rs6603883 GA genotype were associated with lymph node invasion (OR = 2.22, p = 0.027, overdominant model). Our study is the first to demonstrate that FURIN and EPHA2 germline gene polymorphisms are associated with NPC risk (for rs4702) and prognosis (for both rs4702 and rs6603883), with sex-specific differences. These results need to be replicated and further investigated in other populations.

Let T ∈ B(H) be a bounded linear operator on a Hilbert space H with the polar decomposition T =U|T|. The(f,g)-Aluthge transform of the operator T, denoted by ∆f,g(T), is defined as ∆f,g(T) = f(|T|)Ug(|T|), wheref andg botharenon-negativecontinuousfunctionson[0,∞[suchthatf(x)g(x) = x, for all x ≥ 0. In this paper, firstly, we investigate the relationship between this transform and several classes of operators as quasi-normal, normal, positive, nilpotent and closed range operators. Secondly, we show that under some conditions the (f,g)-Aluthge transform possesses the polar decomposition. Lastly, we provide a characterization of binormal operators from the viewpoint of the polar decomposition and the (f, g)-Aluthge transform. 2020 Mathematics Subject Classification. 47A05; 47B49. Key words and phrases. (f,g)-Aluthge transform; quasinormal operato; Polar decomposition; binormal operators.

Objective The aim of this study was to investigate the distribution and genetic determinants of carbapenemase production and colistin resistance among Acinetobacter baumannii isolates recovered from three health care facilities in the city of Batna, Algeria.

Methods A prospective study was conducted between 2021 and 2022 on 46 Acinetobacter baumannii clinical isolates, which were collected and identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antibiotic susceptibility testing was performed using the disk diffusion method and colistin minimum inhibitory concentrations (MICs) were determined by broth microdilution method. Carbapenemase and colistin resist ance determinants were detected by qPCR.

Results The 46 clinical isolates were mainly from the intensive care unit (52.17%) and the burns unit (17.39%). The strains were collected primarily from pus samples (34.78%) and blood samples (17.39%). Eleven strains were classified as colistin-resistant, with MICs ranging from 4 to 128 μg/mL. The blaOXA-24 gene was detected in 63.04% of the isolates, followed by the blaOXA-23 gene (43.47%). Nine strains were positive for both blaOXA-23-like and blaOXA-24-like genes. The blaNDM gene was detected in eight isolates (17.39%), including two which co-expressed a blaOXA-24 gene. In contrast, all strains were negative for the plasmid-mediated colistin resistance mcr-1 to mcr-5 and mcr-8.

Conclusion Here, we report a high prevalence of carbapenemases-producing A. baumannii isolates in Batna hospi tals. Notably, this study is the first to identify A. baumannii isolates co-producing OXA-24 and NDM carbapenemases and to report the first detection of colistin-resistant A. baumannii co-producing OXA-24 and OXA-23 carbapenemases from a patient in Algeria.

Keywords Acinetobacter baumannii, blaOXA-23, blaOXA-24, blaNDM, Algeri