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

This study defines and analyzes the stability radii of stochastic descriptor systems. We utilize generalized Lyapunov
techniques to establish necessary and sufficient conditions for exponential stability. Additionally, the paper aims
to explore robust stability by characterizing the stability radius through generalized Lyapunov equations. To the best of our knowledge, this research is the first to investigate robust stability using the infinite-dimensional
generalized Lyapunov equation.  

This study evaluates the inhibition mechanisms of CaCO₃ scaling in reverse osmosis using Zn⁺⁺ which has been superficially investigated in RO, with only three papers published. In order to do that a novel experimental approach was used; this approach involved a synthetic calco-carbonic solution, with an initial hardness of 60 °F (240 mg/l Ca++) and saturated with CO₂, The CO₂ leakage through the RO membrane allowed the interfacial pH to increase and, thus, accelerated the scaling occurrence. The condition for CaCO₃ precipitation is the solubility product verification: (Ca⁺⁺)* (CO₃⁼) ≥ K_S. In saturation pH, the CO₃⁼ concentration remained at ppm level; masking the CO₃⁼ ligand by Zn⁺⁺, for scaling prevention, was the main research hypothesis. This approach is very different from conventional kinetic and crystallographic theories. Furthermore, the synthetic solution was desalted in batch mode using various Zn⁺⁺ concentrations (0–1.5 ppm); the results showed a 288 minutes induction time without Zn⁺⁺ and 402 mn with Zn⁺⁺ at 1.5 ppm, the saturation pH increased from 7.33 to 8.18, confirming the Zn⁺⁺ efficiency. Also, the pH–time, conductivity–time, [Ca⁺⁺]–time and turbidity–time plotting allowed scaling detection in the fluid bulk; their comparison showed a good correlation. SEM and EDS spectro were used.

The coupling system of two different sources has always been an important subject of research in the field of electrical grids of any voltage range. In particular, after the connection of the photovoltaic and the public grids, the voltages cannot be distinguished from each other, because after their coupling there is one voltage across the output load. In this article, we take into account the variation of the current when the load varies in order to establish the relationship between the measured current and the output AC voltage, which can be regulated using only the current. For this purpose, we employ two types of controllers, the Proportional-Integral-Derivative (PID) controller and the Artificial Neural Network (ANN) controller,using Matlab/Simulink. Despite the connection of aninverter, which increases the loss rate and the error,the results are encouraging considering that the error rate obtained for the ANN controller, which is 1.49%, is much lower compared to that of the PID controller, which is 2.4%. Based on the results obtained, it can be concluded that the ANN controller is the best choice to perform this simulation.

Our paper focuses on the discovery and analysisof a recently identified three-dimensional chaotic model. Thisresearch presents a remarkable system characterised by its easeof implementation, but which exhibits a more complex dynamicbehaviour, exceeding that of many similar chaotic systems. Byunravelling the underlying mechanisms of this system throughthe analysis of eigenvalues, bifurcation diagrams and Lyapunovexponents, its chaotic behaviour is verified by building anelectronic circuit. The experimental behaviour is in agreementwith the numerical studies. This paper paves the way for furtherexploitation of the unique interplay between simplicity andcomplexity in chaotic systems, promising applications in variousscientific disciplines.

Background

The Triple-Negative Breast Cancer (TNBC) molecular subtyping and target identification based on Immunohistochemistry (IHC) is of considerable worth for routine use. Yet, literature on this topic is limited worldwide and needs to be enriched with data from different populations.

Methods

We assessed the IHC expression of subtyping biomarkers (Cytokeratins 5, 14 and 17, Epidermal Growth Factor Receptor, Claudins 3 and 7, E-cadherin, Vimentin and Androgen receptor) and predictive biomarkers (Tumor-infiltrating lymphocytes (TILs) density, Breast Cancer Antigen 1 (BRCA1) and P53) in a cohort of TNBC patients. Clinicopathologic parameters and overall survival (OS) were investigated as well.

Results

The patients were aged 50.11 ± 12.13y (more than 40y in 76.56% of patients), and 23.44% had a BC family history. They were in a non-advanced stage: 51.6% T2 stage, 56.2% negative lymph node involvement, 76.6% without metastasis and 64.1% grade II Scarff-Bloom-Richardson classification (SBR).

The IHC subtypes were: 53.1% Basal-like1 (BL1), 6.3% Basal-like2 (BL2), 17.2% Mesenchymal (MES), 9.4% Luminal Androgen Receptor (LAR), 4.7% Mixed subtype and 9.4% “Unclassified” type. The LAR subtype involved the youngest patients (40.17 ± 8.68y, p = 0.02). The “Unclassified” subtype expressed the p53 mutated-type pattern more frequently (100%, p = 0.07). The BRCA1 mutated pattern and TILs infiltration were present in (23.44% and 37.5% of patients, respectively).

The OS of the subtypes differed significantly (p = 0.007, log-rank test). The subtypes median OS were, respectively, 15.47 mo. (Unclassified), 18.94 mo. (BL2), 27.23 mo. (MES), 27.28 mo. (Mixed), 30.88 mo. (BL1), and 45.07 mo. (LAR). There was no difference in the OS following age, BRCA1 expression, p53 pattern and TILs density. Though, the OS following the TNM stage was different (p = 0.001). A multivariable Cox proportional hazards regression analysis showed that TNM staging and TNBC subtypes, independently influence the OS (p < 0.001 and p = 0.017, respectively).

Hence, IHC is useful in TNBC subtyping for prognostic purposes and in the identification of therapeutic biomarkers. Further investigation is required to confirm our results and to implement IHC as a routine tool to improve patient’s care.

This study set out to examine the thermo-mechanical behavior of gypsum-protected steel columns (GPSC) exposed to fire, including the cooling phase, through numerical analyses with the aim of better understanding the effect of protection materials and identifying the possibility of delayed failure of GPSC during this critical period. A parametric study has been performed with the SAFIR program using a sequentially decoupled thermal structural analysis. The examined factors are the shape of the columns, the fire intensity, and the thickness of the protection. Gypsum serves as insulation, providing passive protection to prevent the degradation of steel mechanical properties and to mitigate and delay the collapse of steel columns during fire exposure. Different thicknesses of gypsum were considered (1 mm, 3 mm, and 5 mm) in order to analyze the effect of the rate of heat storage on the delayed collapse during and after fire exposure. The simulations were performed considering ISO fire and parametric temperature–time curves, which include a cooling regime that is linear. The findings show that the failure of the GPSC over the period of cooling is a possible event where the protection acts as a cooling retarder, which leads to a delayed collapse. Columns with massive sections and thick layers of protection are the most susceptible to delayed failure. Overall, this paper provides a real assessment of the load capacity in a natural fire situation, and the results highlight the possibility of delayed collapse of GPSC.

The article presents a hybrid controller based on the Incremental Conductance (Inc-Cond) and Interval Type-2 Fuzzy Logic (IT-2FL) algorithms as a Maximum Power Point Tracker (MPPT). The controller employs a three-phase Interleaved Boost Converter (IBC), which operates based on the pulses generated by the MPPT to ensure that the photovoltaic (PV) system operates at or near its Maximum Power Point (MPP). IT-2FL enhances the tracking process by applying rule fuzzification and managing uncertainties in response to significant fluctuations in climatic conditions. The proposed controller demonstrates precise and rapid convergence to the MPP, outperforming the individual application of both component methods, as well as traditional fuzzy logic, even when combined with Inc-Cond. The fault tolerance of the proposed tracker is validated through MATLAB simulations under various operational scenarios, evaluating response time, MPP tracking accuracy, efficiency, and other parameters.

This study explores a novel approach to regulate blood glucose levels in individuals with type I diabetes, employing the widely used model predictive control (MPC) strategy in type 1 diabetes mellitus therapy and clinical trials. The MPC algorithm is implemented based on Magdelaine’s long-term glucose-insulin model, which encompasses real-life characteristics often absent in other prevalent models. The control strategy is evaluated through simulations involving 10 virtual patients from existing literature. The simulations encompass fasting scenarios and a closed-loop control scenario involving three meals. MPC results are compared to those of the “optimal” conventional insulin daily injections therapy (open-loop treatment), especially under “aggressive conditions” including elevated initial blood glucose levels, substantial carbohydrate intake, closely spaced meal times, and incorporating a time delay between plasma glucose concentration and its subcutaneous measurement. The MPC algorithm demonstrated remarkable efficacy in glycemic control for 80% of patients, achieving an average time-in-range percentage exceeding 80% with no hypoglycemic episodes. This aligns with the American Diabetes Association’s recommendation of spending at least 70% of the time in the target range for effective glycemic control and maintaining an average time spent in hypoglycemia of less than 4%. However, the same MPC controller exhibited suboptimal performance for two patients, with an average time spent in hypoglycemia exceeding 8%. These findings underscore the need for individualized adjustments of MPC parameters or alternative control strategies to optimize glycemic management in all patients.

This paper presents a novel strain-based finite element (NSBPE4K) developed for the free vibration analysis of thin plates, both with and without cutouts. The element incorporates three primary degrees-of-freedom per node: a transverse displacement (w) and two normal rotations (θx, θy) about the x and y axes, respectively. The displacement field is formulated based on assumed functions for the strain components, ensuring the compatibility equations are satisfied. The non-conforming element was successfully implemented in the ABAQUS software using the UEL subroutine (user element). Free vibration analysis results demonstrate the exceptional efficiency and accuracy of the new element. The results obtained with the present element excel those obtained with standard ABAQUS elements and other non-conforming elements found in the literature. This superiority is noticeable in free vibration scenarios, demonstrating the effectiveness of the proposed finite element for accurate and reliable simulation of the vibrational behavior of thin plates.

Conductors serve as essential components in various electrical and electronic applications (steel, aircraft, and nuclear industries). Therefore, an accurate evaluation of their electrical parameters, in particular their electrical conductivity (σ), remains critical for assessing their performance in industrial processes. Although numerous eddy current based methods exist for conductivity measurement, this study approaches the problem through inverse problem solving. A novel approach integrating Eddy Current Testing (ECT) with Artificial Neural Networks (ANNs) is proposed to determine electrical conductivity from probe impedance measurements. An experimental setup has been developed that includes a custom-designed bobbin coil probe used in conjunction with metal plate samples (targets) and data acquisition and signal processing systems. To validate the introduced approach, conductivity values predicted by the ANN model were rigorously compared with reference measurements obtained using the four-point Direct Current Potential Drop (DCPD) technique. This comparative analysis demonstrates the robustness and measurement fidelity of the proposed approach.

Solar power plants that incorporate parabolic trough collectors (PTC) to generate solar energy can be regarded as a viable alternative to conventional power plants. To enhance the performance and productivity of these systems, it is imperative to improve the direct steam generation process. This study proposes the implementation of a passive enhancement technique to improve steam production in the PTC absorber, with the aim of optimising the overall size and cost of solar power plants. For this purpose, longitudinal fins have been attached to the inner bottom part of the tube. A numerical investigation was conducted to examine the two-phase flow with vaporisation using the ANSYS Fluent code. The analysis of two-phase flow was carried out via the volume of fluid technique. Additionally, a phase-change model was integrated to elucidate the vaporisation process. The Monte-Carlo ray-tracing approach was employed to identify the irregular distribution of heat flux across the tube. The integration of fins within the absorber tube has been demonstrated to enhance heat transfer and vapor fraction, thereby optimising the thermal performance of the system. Furthermore, the configuration that optimised steam generation was achieved through the utilisation of an absorber tube equipped with two rectangular longitudinal fins, displaying an aspect ratio of 0.5. The optimum thermal performance factor was found to be 1.58, which is reached in the laminar regime. The study's findings indicate a reduction in the overall dimensions of the PTC absorber, leading to a decrease in the size of solar power plants and their associated costs.