Maximum Allowable Research Articles

A comparison of operating room toric placement tools: CALLISTO eye vs. e Wavetec AnalyzOR (CORTCO)

BackgroundTo evaluate procedure times for two cataract planning systems (ZEISS CALLISTO eye and the Wavetec AnalyzOR) in predicting residual astigmatism (prediction error) and other visual outcomes in patients with corneal astigmatism (maximum allowable up to 3.0D) at postoperative month 1.MethodsThis was a prospective, single center, parallel treatment group, bilateral and unilateral, randomized, 1-month study on patients scheduled to undergo routine, small-incision cataract surgery with a toric intraocular lens implantation. Both groups underwent preop measurements with the IOLMaster 700 (Zeiss, Jena, Germany) and surgery with the LenSx device (Alcon). Lens selection in the CALLISTO eye group was based on Zeiss VERACITY Surgery Planner (a web-based tool) and on the Wavetec AnalyzOR component of the ORA system (a real-time intraoperative aberrometer) for those eyes in the ORA group. All procedure and intraoperative times were measured with a stopwatch. Postoperative visual outcomes were evaluated between 1 and 2 months after surgery.ResultsThere were 23 eyes in the CALLISTO group and 28 eyes in the ORA group. The mean surgical time for the CALLISTO group was 28.09 ± 1.72 min compared to 34.41 ± 1.52 min for the ORA group (P = 0.01). Toric lens placement mean time in the CALLISTO group was 2.47 ± 0.34 min compared to 3.88 ± 0.29 min in the ORA group (P = 0.0034). At month 1 postoperatively, the manifest refractive spherical error (MRSE) in the CALLISTO eye group 0.022 ± 0.388 diopters (D) compared to -0.174 ± 0.322 D in the ORA group; these were not statistically different. There was a higher percentage (75%) of eyes with an MRSE within 0.25D in the ORA group compared to the CALLISTO eye group (56.5%); at all other levels outcomes were numerically higher in the CALLISTO eye group.ConclusionsLess surgical time was needed when using the CALLISTO eye than the ORA when performing cataract surgery with toric lens implantation. There were similar visual outcomes between the groups and no statistical differences.

Bandwidth Management with Mikrotik OS Routers Using the Per Connection Queue Method

Services that use the Internet as Business Cafe, Online Games, education, defense and security, online businesses, e-mail service providers, and others will experience barriers in carrying out their activities. Often problems arise in internet service providers are setting up or managing broadband. The implementation of broadband management is aimed at optimizing the bandwidth available to provide broadband guarantees for Internet users, such as network congestion (through traffic) and unstable broadband received by Internet service providers (ISPs). Bandwidth management in Mikrotik with the PCQ (Per Connection Queue) method, basically, uses queue methods for the bandwidth balance used on multiple clients. The main purpose of this method is to automatically and unevenly share bandwidth sharing, with a simple turn-line if only one subscriber actively uses another temporary bandwidth will be in the standby position, then the subscriber can use maximum bandwidth which is available, but if another customer is active, then the maximum bandwidth can be used by both customers who have maximum width / 2, if there are subscribers at the same time active, each will receive the maximum bandwidth allowance / all clients, so will not be a fair wide-ranging distribution for all customers.

The efficiency of portable air cleaners in reducing cross-exposure through respiratory aerosols: Effects of flowrate, location, and unit type

This study evaluates the efficacy of portable air cleaners (PACs) in a controlled climate chamber that simulates an office environment, assessing their impact on respiratory particle transmission between two thermal manikins (representing an infected and an exposed individual) as well as on the noise level in the chamber. The study explores three types of PAC, namely floor-type (PAC1), table (PAC2) and personalized (PAC3) in various locations and operation modes. The particles were generated using an aerosol generator and introduced into the infected manikin's exhalation; the particle concentration at the exposed manikin's breathing zone (BZ) was measured using an aerodynamic particle sizer. The results showed that the PAC2, operating at a flow rate of 97 m³/h, significantly reduced the intake fraction (IF) by over 90 % within the first hour, proving to be the most effective in minimizing cross-exposure risks while maintaining sound levels within the acceptable limits for office rooms. In contrast, PAC3, with a lower flow rate of 13 m³/h, reduced IF by only 21.6 % after 60 min. The result also showed that settings with higher flow rates (higher than 134 m3/h) resulted in noise levels above the maximum allowable for office spaces for all tested PACs. Additionally, prolonged operation did not further decrease IF significantly after reaching optimal reduction levels within 30–60 min, depending on the PAC type and settings. Further, the study showed that strategic placement away from direct alignment with occupants' BZ is recommended to optimize aerosol removal and noise management.

A calculation method for ultimate and allowable loads in high-pressure thick-walled worn casing

Casing wear has become a critical issue in oil and gas drilling, significantly reducing casing burst strength. As exploration and development progress, the number of high-pressure, ultra-deep wells continues to rise, requiring high-strength, thick-walled casings capable of withstanding ultra-high internal pressures. However, research on the strength characteristics of worn high-strength, thick-walled casings under such conditions remains limited. This study fills that gap by quantitatively evaluating worn casings to determine the maximum allowable internal pressure, particularly for high-pressure, thick-walled casings. A systematic analysis of existing methods for calculating the ultimate load of casings is conducted, and a suitable approach for high-grade steel casings is proposed. A parametric finite element model (FEM) of worn casings was developed to assess the impact of various dimensionless structural parameters, including the thickness ratio (Do/t), wear percentage (h/t), wear circle ratio (2ri/Do), and nominal yield strength (Rp0.2), on the ultimate load. The results demonstrate that both wear depth and casing dimensions significantly affect the ultimate load. A new formula is proposed for calculating the ultimate and allowable loads of worn casings based on the results of a finite element analysis. This formula is applicable to high-strength casings of varying wall thicknesses, particularly under ultra-high pressure.

A-150 Extended Pre-Analytical Stability Validation for Coagulation Tests in Brazilian Clinical Laboratory

Abstract Background The transport of samples for coagulation tests is a challenge for clinical laboratories, due to their limited stability and short time for processing according to the manufacturer's recommendations. The objective of this study was to evaluate the possibility of extending the stability of samples collected for Prothrombin Time and Activity (PTA), activated Partial Thromboplastin Time (aPTT) and Fibrinogen tests for up to 10 hours at room temperature, in comparison with the stability described in the literature and by the manufacturer of the reagents (4 hours for aPTT, 8 hours for PTA and Fibrinogen). We verified the acceptability of the samples with a longer period between collection and analysis, including its impact on the clinical management Methods Four tubes of 3.2% sodium citrate from 40 volunteers were analyzed at times of up to 4 h, 6 h, 8 h and 10 h. The results obtained were compared with the dosage performed within 4 hours (recommended by manufacturer) and the Total Error obtained in the analysis of the samples was evaluated. The tubes remained at controlled room temperature of 15 to 25°C and were centrifuged at 1500 g for 15 minutes. Then, the analyses were performed by coagulometric method. Results The results showed safety in the analysis of samples for coagulation tests even within 10 hours after collection at ambient temperature and were within the Maximum Allowable Total Error (Carmen Ricós): 95% of the PTA results (TE 5,3%); 92.2% of aPTT results (TE 4,5%) and 98% of Fibrinogen analyses (TE 13,6%) (Figures 1, 2 and 3). In addition, even the results that exceeded the specified Total Error showed no impact on the clinical decision. Conclusions The study demonstrated that there was no significant loss of stability for the analyses of PTA, aPTT and Fibrinogen performed on samples kept at room temperature within 10 hours after collection. Most of the results showed variation within the specified Total Error and all results showed acceptability from a medical point of view

Histological Based Environmental Monitoring of the Lower Nun River: Using the Histo-morphometry of Kidney, Gills, Liver, and Testes of Coptodon zillii

It is an ecotoxicological study aimed at using chemical and bio-monitoring methods to pollution status of the Lower Nun River (LNR) basin using the histo-morphometry of the Liver, Kidney, Gills, and the Testes of Coptodon zillii. Based on literature review on the environmental burdens of the LNR, the following Target Chemicals (TC) were chosen for the study: Cadmium (Cd), Chromium (Cr), Copper (Cu), Nickel (Ni) and Lead (Pb). The study involved the sampling of water, sediment and feral fish from two stations along the LNR, Peremabiri (PER) and Igbomotoru(IGB) – Experimental sites.Water and sediment samples were analyzed to ascertain the physico-chemical concentrations of potential contaminants, while the harvest fish organs of liver, kidney, gills and testes were subjected to histological study to ascertain the exposure effect. Control fishes were harvested from African Aqua-culture Centre (ARAC) – Reference Site. Analyzed sediment and water values were used to evaluate Environmental Water Quality Index (EWQI) and sediment quality, while the fish organs were analyzes and used for pollution certification and stratification. Study results showed that EWQI of PER was poor (41.9); sediment quality showed that Cr, CU and Pb were above the Maximum Allowable Toxicant Concentration (MATC) for fresh water body. Fish from IGB showed worse lesion prevalence and organ histopathologic Index (Iorg) when compared to PER, with ARAC having the best outcome. The environmental pollution status (EPS) LNR was normal at PER and was slightly polluted at IGB. The study gave credence to the use of histology as a biomarker to assess sublethal effects of environmental stressors, and in determination of the pollution status.

Feasibility of Metrological Traceability Implementation Using the Joint Committee on Traceability in Laboratory Medicine Database Entries Including the Fulfillment of "Fit-for-Purpose" Maximum Allowable Measurement Uncertainty.

In previous publications, the Task Force on Reference Measurement System Implementation proposed a procedural approach combining a critical review of entries available in the Joint Committee on Traceability in Laboratory Medicine (JCTLM) database with a comparison of this information against analytical performance specifications for measurement uncertainty (MU) and applied it to a group of 13 measurands. Here we applied this approach to 17 additional measurands, of which measurements are frequently requested. The aims of the study were (a) to describe the main characteristics for implementing traceability and the potential to fulfill the maximum allowable MU (MAU) at the clinical sample level of certified reference materials and reference measurement procedures listed in the JCTLM database; (b) to discuss limitations and obstacles, if any, to the achievement of the required quality of laboratory measurements; and (c) to provide a gap analysis by highlighting what is still missing in the database. Results were integrated with those obtained in the previous study, therefore offering an overview of where we are and what is still missing in the practical application of the metrological traceability concept to 30 common biochemical tests employed in laboratory medicine. Our analysis shows that for 28 out of 30 measurands, conditions exist to correctly implement metrological traceability to the International System of units and fulfill at least the MAU of the minimum quality level derived according to internationally recommended models. For 2 measurands (serum albumin and chloride), further improvements in MU of higher-order references would be necessary.

LP-48 Derivation of a Maximum Allowable Dose Level (MADL) for Bisphenol S and associated challenges

LP-48 Derivation of a Maximum Allowable Dose Level (MADL) for Bisphenol S and associated challenges

The Long-Term Performance of a High-Density Polyethylene Geomembrane with Non-Parametric Statistic Analysis and Its Contribution to the Sustainable Development Goals

The tailings from gold beneficiation can cause various negative impacts, necessitating measures to prevent their transport and environmental contamination. Geomembranes serve as hydraulic barriers in mining tailings reservoirs, thereby supporting the Sustainable Development Goals (SDGs). To ensure that the geomembrane effectively mitigates environmental impact, it is essential to study its durability when applied in the field. This article examines the long-term performance of an HDPE geomembrane exposed for 7 and 11 years at a gold mining tailing site in Brazil. Samples were exhumed from different locations at the dam, and their properties were evaluated. Non-parametric statistics were employed using the Kernel Density Estimator (KDE). For the 11-year-old geomembranes, the probability of the geomembrane reaching nominal failure in terms of tensile strength was 0.4%. The peel separation values exceeded the maximum allowable by the GRI GM13 standard. Although the geomembranes showed significant antioxidant depletion, suggesting they were close to or had already reached their residual stages, they approached nominal failure based on their stress crack resistance but did not rupture. The environmental analysis indicated no significant contamination in the area, corroborating that the geomembrane is fulfilling its function. The non-parametric methodology proved promising for durability analysis and could be applied to other engineering projects with geosynthetics, thereby adding reliability to decision-making in alignment with sustainable development.

Trajectory control strategy for multi-tool synchronous electrochemical machining of blisk channels

The blisk is a core component of an aero-engine, and electrochemical machining (ECM) is the primary method for its manufacture. Among several ECM methods for blisks, multi-tool synchronous machining is the most efficient and advantageous for machining channels. The allowance distribution of the blank after blisk channel machining directly influences the blade profile accuracy. This paper proposes a trajectory control strategy to homogenize the allowance distribution of the blisk channel in multi-tool ECM. The strategy includes the design of the three-dimensional space motion of the tool and blisk, as well as the regulated feed speed. The structural characteristics of the blisk channel and the principle of ECM allow for designing and optimizing the multi-dimensional trajectory. The electric field simulations elucidate the influence law of the three-axis feed speed on the side gap. An algorithm is adopted to iteratively optimize the speeds for different positions to realize multi-dimensional motion control and allowance homogenization. The proposed trajectory control strategy is applied to ECM experiments for the blisk channel. Compared with the constant feed speed mode, the regulated speed strategy reduces the maximum allowance difference between the convex (CV) profiles by 36.18% and that between the concave (CC) profiles by 37.73%. Subsequently, the one-time ECM of eight blisk channels was successfully realized. The average time for a single channel was 12.5 min, significantly improving the machining efficiency. In conclusion, the proposed method is effective and can be extended for synchronously machining various blisk types with twisted channels.

Effects of reducing copper and zinc supplementation on the performance and mineral status of fattening pigs

Pig manure with high copper (Cu) and zinc (Zn) concentration is applied to the soil, and these trace minerals can accumulate in the topsoil and decrease its fertility. Thus, adjusting concentrations of Cu and Zn in pig diets below current maximum allowance can prevent this risk. Reduction of dietary concentrations of Cu and Zn reduces their faecal excretion since only a small portion is retained in the pig’s body. The aim of this study was to evaluate the effects of reducing concentration of dietary Cu and Zn or withdrawing their supplementation on the performance and mineral status of fattening pigs. Four dietary treatments were compared: a basal diet (WS; withdraw supplementation), with no Cu or Zn supplementation (5 and 29 mg/kg of native Cu and Zn, respectively); intermediate concentration (OINT), supplemented with Cu and Zn oxides to obtain mean dietary concentration of 7.4 and 47.5 mg/kg of Cu and Zn, respectively; and two diets supplemented with oxides (OREG) or sulphates (SREG) at concentration similar to European Union limits (i.e. 25 and 120 mg/kg of total Cu and Zn, respectively), as commonly used on commercial farms. Ninety-six pigs (24.3 ± 3.3 kg BW) were each assigned to one of the four treatments and reared in individual pens for 14 weeks (up to 110.3 ± 8.9 kg BW). Animal performances were measured, and samples of plasma (on day 1 and day 41 of experimentation and at slaughter), bones and the liver (at slaughter) were collected from all pigs. Faecal samples were collected from all pigs every 3 weeks to determine the Cu and Zn excretion. Over the entire experiment, neither the concentration nor the source of Cu and Zn influenced feed intake, BW or the feed conversion ratio. Plasma Cu and Zn concentrations were not influenced by the treatment but increased as the age of the pigs increased. Liver Cu concentration increased (P < 0.05) as dietary concentrations increased (OREG> WS). Neither the concentration nor the source of Cu and Zn influenced bone Cu and Zn concentration or physical bone parameters. However, SREG had a higher maximum load until bone breaking (P < 0.05) than OREG. As expected, faecal excretion of Cu and Zn decreased (P < 0.01) as dietary concentration decreased. Dietary Cu and Zn can be reduced without decreasing the performance or mineral status of pigs, and these results should be validated on commercial farms that have more challenging health conditions.

Optimization of handoff for joint uplink base station association and power control with max‐min fairness in NOMA small‐cell networks

SummaryThe handoff rate and load balancing are two important issues that have a great impact on the spectrum and energy efficiency in the small‐cell networks (SCN). This paper investigates the handoff optimization in SCN with power‐domain non‐orthogonal multiple access (NOMA) that uses successive interference cancelation (SIC), considering the fairness among base stations (BSs). We study the joint base station association and power control problem by considering the motion of mobile users (MUs) and load balancing in the SCNs. Under the maximum allowable transmit power and minimum average‐rate constraints, two optimization problems are formulated using the number of associated MUs, the number of handoffs, and the transmit power of all MUs. The total power consumption minimization and the system‐wide and handoff utility maximization problems are combined into a single‐stage optimization problem through the weighted‐sum method. We solve the formulated problem using a game theory‐based algorithm and primal decomposition theory. The simulation results show that our proposed algorithm can significantly reduce the frequent handoffs and bring a fair power‐controlled BS association in SCN.

Do lead (Pb) content of lipsticks expose a health risk to children? A risk assessment study.

Lead (Pb) content in lipsticks and potential life-long exposure of which might cause severe effects in consumers are an important concern for public. Thus, studies emphasize that lead exposure has no safe levels. From 10 different brands, in total, 25 solid, gloss and creamy lipsticks are deployed from Turkish markets that are also categorized in two different price ranges. In order to evaluate the blood Pb levels in children, the United States Environmental Protection Agency's 'Exposure Uptake Biokinetic Model' is utilized. To assess the health risk of chronic usage both for children and adults, oral daily systemic exposure levels are calculated with the worst-case scenario and are compared with Maximum Allowable Dose Level for lipsticks. For lifetime risk assessment, exposure is assumed to start by age 7, and four different exposure scenarios have been deployed. The mean lead content of lipsticks shows significant statistical differences between the high- and low-priced lipstick groups. Daily level and total risk for lifetime Pb exposure from deployed lipsticks are below the acceptable risk levels but long-worn usage of products with routine monitoring of metal content is crucial for sensitive and unintended exposure groups.

Sampled-data observer design for Linear Kuramoto–Sivashinsky systems with non-local output

The aim of this paper is to provide a novel systematic methodology for the design of sampled-data observers for Linear Kuramoto–Sivashinsky systems (LKS) with non-local outputs. More precisely, we extend the systematic sampled-data observer design approach which is based on the use of an Inter-Sample output predictor to the class of LKS systems. By using a small-gain methodology we provide sufficient conditions ensuring the Input-to-Output Stability property of the estimation errors in the presence of measurement noise. Our Inter-Sample output predictor contains a tuning term which can enlarge significantly the Maximum Allowable Sampling Period.

Water quality aspects from Spanish sites to support managed aquifer recharge (MAR) guidelines not based on maximum allowable concentration standards

Most countries that have technical guidelines or regulations for artificial recharge or managed aquifer recharge (MAR), that include water quality aspects are based on the establishment of standards or Maximum Allowable Concentrations (MACs) to regulate the quality of the water percolated or injected into an aquifer. The number of parameters in these guidelines vary considerably (from 6 in Spain to 156 in the USA) and often apply to all aquifers within administrative boundaries (e.g., national territory), regardless of the nature of the receiving medium, the depth of the water table, and other key factors. Eleven MAR systems in Spain have been studied (eight operational and three experimental, with limited number of data from three sites), characterising both, the recharge water quality and the water resulting from the interaction processes recharge water-soil-unsaturated zone-saturated zone of the aquifer. In all cases, an improved effect on groundwater quality is observed, even though some parameters in the recharge water don’t comply with the standards employed in some European countries, where this article focuses. The article suggests that regulating water quality for MAR through MACs at national level gives room for another alternative approach specific for each site. It might be recommendable to establish local standards at the regional or aquifer-wide level to better reflect the diversity of groundwater occurrence. As per the article, sectoral water authorities could receive more decision-making power on granting permits for MAR based on the quality of the hydrogeological and risk studies for each request. This would help reduce the application of the precautionary principle when in granting permission.

Serviceability of railway slab track foundations with retaining walls under train loading

ABSTRACT Railway retaining wall designs tend to disregard vehicle-induced trackbed deformation control, despite its potential impact on infrastructure serviceability. To fill this gap, this study seeks to develop an improved method to assess the performance of railway gravity retaining walls, specifically focusing on managing slab trackbed deformation. Utilizing a validated 3D numerical model, the research examines the impact of five parameters – wall width, location, inclination, embankment height, and ground-bearing capacity – on trackbed surface displacement (ω) arising from train loading. The multivariate adaptive regression splines (MARS) approach is applied to establish the mathematical relationship between these factors and an assessment indicator for evaluating track foundation serviceability. This indicator is the trackbed surface displacement index (R ω ), signifying the ratio of the maximum allowable to the practical ω value. Results highlight the necessity for comprehensive retaining wall design to ensure R ω ≥1.0, particularly when the wall is near the track, steeply inclined, or supporting a tall embankment.

COMPARATIVE ANALYSIS OF THE ELEMENTAL COMPOSITION OF ORGANS OF PROMISING SPECIES OF THE GENUS IRIS L. (IRIDACEAE)

Plants of the genus Iris L. are promising medicinal raw materials with significant biological and pharmacological activity. The quality of plant raw materials depends on the accumulation and distribution of potentially hazardous chemical elements in the plant body. The aim of this work was a comparative study of the accumulation and transfer of elements through the organs of plants of the genus Iris L. (Iridaceae). The content of As, Cd, Cr, Cu, Mn, Ni, and Pb in different parts of I. orientalis, I. pseudacorus, I. sibirica and I. spuria plants was analyzed by atomic absorption. It has been established that in the absence of soil pollution, irises accumulate arsenic in concentrations exceeding the maximum allowable. The accumulation of chromium in the raw material was also above the maximum allowable concentration for a number of study options. The efficiency of element transfer from the soil to the root system varied significantly (bioaccumulation factor 0.2–4.4). Iris rhizomes absorbed nickel most actively. The assimilation ability of the roots is also clearly expressed in relation to Pb, As, Cr, Cu, Mn. Depending on the element, accumulation in leaves is species-specific. The carrying capacity of the peduncle is most pronounced in I. sibirica, the barrier capacity is most pronounced in I. orientalis. Various types of translocation of elements in organs were revealed: acropetal, uniform, basipetal. All studied species are characterized by acropetal distribution of Pb (translocation factor &gt;1) and uniform distribution of Mn. The location of Cd may vary depending on the species. Cu is concentrated in the roots (I. orientalis, I. sibirica, I. spuria) or evenly distributed (I. pseudacorus). The revealed patterns of accumulation and distribution of elements in the organs of plants of the genus Iris make it possible to carry out a prognostic assessment of the quality of raw materials to obtain safe products.

ВЛИЯНИЕ НЕКОТОРЫХ ЗАГРЯЗНЯЮЩИХ ВЕЩЕСТВ НА НЕКТОБЕНТИЧЕСКИХ РАКООБРАЗНЫХ

Background. Ingress of pollutants in water bodies, both direct and from the catchment area, is constantly increasing. It creates an escalating threat to aquatic ecosystems and humans as consumers of water and aquatic biological resources, which contributes to the relevance of the monitoring and regulation of water pollution. This work is aimed at the evaluation of the effect of various toxic substances and pollutants on the survival of the amphipod Hyalella azteca in a chronic experiment. Methods. This study has been carried out according to the standard toxicological methods. Results. This paper presents the data on the influence of pollutants of various nature (sodium hydrogen phosphate, sodium sulfate, zinc complex of 2-Phosphono-1,2,4-butanetricarboxylic acid, dimethyl sulfide) on the Hyalella azteca Saussure, 1858 crustaceans. Hyalella azteca have found a wide application in biotesting; however, these crustaceans are not used in the system of fisheries regulation in Russia. The maximum allowable and threshold concentrations of the investigated substances in the aquatic environment have been established for Hyalella azteca using the experimental approach. The maximum allowable concentration (MAC) of sodium hydrogen phosphate in the phosphorus equivalent was 1.0 mg/L, its threshold concentration was 2.5 mg/L; the MAC of sodium sulfate in the sulfate anion equivalent was 750 mg/L, its threshold concentration was more than 750 mg/L; the MAC of the zinc complex of 2-Phosphono-1, 2,4-butanetricarboxylic acid was 10 mg/L, its threshold concentration was 100 mg/L; the MAC of dimethyl sulfide was 10 mg/L, its threshold concentration was 20 mg/L. Conclusion. The amphipods H. azteca are moderately sensitive to pollutants. Among all investigated substances, the most toxic for H. azteca was sodium hydrogen phosphate.

Determining Maximum Allowable Current of an RBS Using a Directed Graph Model and Greedy Algorithm

Reconfigurable battery systems (RBSs) provide a promising alternative to traditional battery systems due to their flexible and dynamically changeable topological structures that can be adapted to different battery charging and discharging strategies. A critical system parameter known as the maximum allowable current (MAC) is pivotal to RBS operation. This parameter is instrumental in maintaining the current of each individual battery within a safe range and serves as a guiding indicator for the system’s reconfiguration, ensuring its safety and reliability. This paper proposes a method for calculating the MAC of an arbitrary RBS using a greedy algorithm in conjunction with a directed graph model of the RBS. Using the shortest path of the battery, the greedy algorithm transforms the exhaustion of the switch states in the brute-force algorithm or variable search without utilizing structures in the heuristic algorithms in the combination of the shortest paths. The directed graph model, based on an equivalent circuit, provides a specific method for calculating the MAC of a given structure. The proposed method is validated using 2 previously published RBS structures and an additional one with a more complex structure. The results are the same as those from the brute-force algorithm, but the proposed method substantially improves the computational efficiency, being theoretically N s 2 N s − N b log 10 N b times faster than the brute-force algorithm for an RBS with N b batteries and N s switches. Another advantage of the proposed method is its ability to calculate the MAC of RBSs with arbitrary structures and variable batteries, even in scenarios with random isolated batteries.

Improving Press Bending Production Quality through Finite Element Simulation: Integration CAD and CAE Approach

Efficient operations and output of outstanding quality distinguish superior manufacturing sectors. The manufacturing process production of bending sheet metal is a form of fabrication in the industry of manufacture in which the plate is bent using punches and dies to the angle of the work design. Product quality is influenced by plate material selection, which includes thickness, type, dimensions, and material. Because no prior research has concentrated on this methodology, this research aims to determine V-bending capacity limits utilizing the press bending method. The inquiry employed finite element analysis (FEA), along with Solidworks was the tool of choice to develop drawings of design and simulations. The ASTM E290 standard guides this study. The software in this package may combine CAD (Computer-Aided Design) and CAE (Computer-Aided Engineering) without requiring extra design applications. This study tested SPCC and SPHC plate materials with five thickness variations. The findings embrace the number of failure risks associated with press bending exhibited on the von Mises stress diagram, which is directly proportional to showing the thickness limit of each material type throughout the bending process. The study's findings lay the groundwork for improving manufacturing quality by lowering the number of faulty goods produced by trial and error. Because the maximum allowable die width is 12 mm, the thickness limit of the press bending process is 2 mm. However, due to the greater intensity of the SPCC material, it has a reduced defect rate compared to SPHC material.