Replacement Parts Research Articles

An uncertainty-aware deep learning ensemble approach for effective cutting tool predictive maintenance decision-making

Abstract As the manufacturing sector increasingly emphasizes production efficiency and product quality, predicting cutting tool remaining useful life (RUL) and conducting failure analysis become essential for ensuring continuity and reducing costs. However, the uncertainties in the tool wear process complicate accurate predictions and decision-making. This paper introduces a predictive maintenance decision-making approach using an ensemble model of convolutional neural network and bidirectional long short-term memory quantile regression (CNN-BiLSTMQR), enhanced by an attention mechanism and kernel density estimation (KDE). Firstly, signals related to tool wear are collected from various sensors, and a convolutional neural network (CNN) captures spatial features and local patterns in the data. These features are then input into a bidirectional long short-term memory (BiLSTM) network, which integrates a temporal attention mechanism and quantile regression (QR) to predict RULs at multiple quantiles. Subsequently, KDE generates the probability density distribution of the tool RULs. Finally, the costs and time associated with maintenance decisions are assessed to derive cost functions for tool replacement and ordering. By minimizing the two functions, the optimal timing for tool replacement and spare parts procurement is identified. Validation with a publicly available tool wear prediction dataset demonstrates that the proposed method effectively reduces maintenance costs while ensuring the safe and reliable operation of tools.

Comparison of the effectiveness of blacklight blue lamp and wood lamp in the screening of tinea capitis

Background: Tinea capitis is a common fungal infection of the scalp in children. Most cases are caused by Microsporum canis or Trichophyton mentagrophyte. Wood lamps screen for tinea capitis by detecting green-yellow fluorescence produced by tryptophan metabolites. Because wood lamps are expensive and replacement parts are difficult to find during maintenance, we have developed a blacklight blue lamp device with a similar wavelength that is cheaper than wood lamps. Objective: To evaluate the BLB lamp device for screening tinea capitis by determining the sensitivity, specificity, and accuracy compared to fungus culture (gold standard). Materials and methods: One hundred seventy-five patients with suspected tinea capitis were tested using KOH examination, fungal culture, a Wood lamp, and a blacklight blue lamp device. The research data obtained will be used to analyze the sensitivity, specificity, and accuracy of the blacklight blue lamp device by comparing it using various methods. Results: The analysis assessed the sensitivity, specificity, and accuracy of the blacklight blue lamp device, Wood lamp, and KOH preparation when comparing fungal culture as the standard method for diagnosing tinea capitis. The sensitivity was 99.39%, 100%, and 100%, specificity was 100%, 90.91%, and 100%, and accuracy was 99.43%, 99.43%, and 100%, respectively. The p-value for the three methods’ differences was 0.723 for sensitivity, 0.735 for specificity, and 0.676 for accuracy. These results show that the differences between the two methods’ sensitivity, specificity, and accuracy were not statistically significant. Conclusion: The blacklight blue lamp device effectively screened tinea capitis with a sensitivity, specificity, and accuracy that were not significantly different from the wood lamp. It may be an inexpensive tool used as a substitute in the health service system.

Legal and Operational Analysis of Compensation for Spare Part Replacement in Car Rental Services Perspective Wahbah Zuhaili

Legal and Operational Analysis of Compensation for Spare Part Replacement in Car Rental Services Perspective Wahbah Zuhaili

Multi-source information fusion based fault diagnosis for complex electromechanical equipment considering replacement parts

Multi-source information fusion based fault diagnosis for complex electromechanical equipment considering replacement parts

Design and mechanical analysis of bushings made from TPU using additive manufacturing and the finite element method

The study focused on analyzing the mechanical behavior of a front suspension fork bushing for an all-terrain vehicle (ATV), manufactured using Thermoplastic Polyurethane (TPU) through additive manufacturing, specifically 3D printing. This technology enables the creation of customized designs, reduces production time, and minimizes material waste. TPU, an elastomer with remarkable physical and mechanical properties, was evaluated as a potential substitute for natural rubber, which is the primary material traditionally used for bushings in the automotive industry, especially in the production of tires, hoses, and seals. The analysis was conducted through CAD modeling and finite element simulations, subjecting the bushing to torsional and shear stresses typical of vehicular suspension systems. The results indicated that TPU could serve as a replacement material for the established requirements. Given that replacement parts are not always acquired in a timely manner, the study focuses on providing a viable alternative for the automotive industry.

Comparison of Efficacy between Thai-Made Replacement Parts (Smart Litho Plus) and Standard Electromagnetic Shock Wave Systems for Renal Stone Treatment

Comparison of Efficacy between Thai-Made Replacement Parts (Smart Litho Plus) and Standard Electromagnetic Shock Wave Systems for Renal Stone Treatment

The Power of 3D Printing

Once limited to industrial prototyping, additive manufacturing has evolved significantly to become a vital asset to the pumps industry, enabling the rapid production and replacement of precise, obsolete and custom component parts

Joint Optimization of Preventive Replacement and Spare Part Ordering for Single‐Unit Systems With Mixed Inspections

ABSTRACTThis paper introduces a unified policy for preventive replacement and spare parts ordering for systems whose degradation follows a gamma process. It considers types of orders, each with variable lead times, and employs a combined inspection approach that integrates sequential and opportunistic inspections to monitor the system condition. The proposed policy coordinates the scheduling of spare parts orders, preventive replacements, and inspections based on the current state of the system. To assess its performance, the renewal reward theorem is used to calculate the average cost rate, the average availability, and the mean time to the first failure. The objective is to minimize the average cost rate, achieved through a grid search algorithm that identifies the optimal inspection and ordering policy. The effectiveness of the proposed policy is further validated by comparing its performance with three other policies in existing research works.

On the Growth of Small Cracks in 2024‐T3 and Boeing Space, Intelligence and Weapon Systems AM LPBF Scalmalloy®

ABSTRACTThe desire to use additively manufactured (AM) parts to ensure the availability of military aircraft, and to build limited‐life unmanned aerial vehicles (drones), coupled with the United States Air Force (USAF) approach to the airworthiness certification of AM parts has focused attention on durability analysis/assessment, and hence on the growth of small cracks in AM parts. Previous studies have shown that laser powder fusion built (LPBF) Scalmalloy® has: i) A yield stress and an ultimate strength that are greater than that of AA2024‐T3 and comparable to that of AA7075‐T6; ii) A resistance to crack growth that is better than that of AA7075‐T6 and comparable to that of AA2024‐T3. However, since the ability to predict the durability of a part is essential for its airworthiness certification, the present paper illustrates how to perform a linear elastic fracture mechanics (LEFM)‐based durability assessment of Boeing Space, Intelligence and Weapon System (BSIWS) LPBF Scalmalloy®. The durability study includes specimens with both machined surfaces and surfaces left in the as‐built condition. As a result, it would appear that BISWS AM LPBF Scalmalloy® is an ideal candidate for building limited‐life AM replacement parts for fixed and rotary wing aircraft and drones.

Environmental and Economic Impact on Scenario-Based Automotive Part Replacement: Case Study of Constant Velocity (CV) Joint Replacement in Korea

The objective of this study is to comprehensively evaluate the environmental and economic impacts of remanufactured constant velocity (CV) joints using a newly proposed framework for automotive parts replacement. This framework utilizes actual vehicle sales data to accurately estimate the demand for CV joint replacements. Specific parameters are established to calculate this demand, enabling a quantitative assessment of both environmental and economic impacts associated with remanufacturing CV joints and other automotive parts. Additionally, sensitivity analyses are conducted to explore the relationship between environmental benefits and economic outcomes, particularly focusing on the preferences for remanufactured parts and their profitability. The results indicate that increasing the proportion of remanufactured CV joints significantly benefits the environment by reducing CO2 emissions, raw material usage, and energy consumption. However, this shift also leads to a decrease in total profits within the CV joint replacement market. To address this trade-off, the study suggests that financial incentives, such as subsidies or tax benefits, are necessary to support the remanufacturing industry and facilitate market expansion. These findings provide valuable insights for policymakers aiming to promote sustainable manufacturing practices through effective subsidy policies.

Design and Finite Element Analysis of a Thin Cross-Section Soft Continuum Manipulator

Soft continuum robots and manipulators (SCRaMs) are mechanisms having elongated bodies. Most SCRaMs employ a thick cross-section body which constrains their maximum bending ability. This paper presents the design of a soft continuum manipulator employing a thin body cross-section. The manipulator’s modular design consists of three sections to facilitate maintenance and parts replacement. The manipulator’s critical components were tested through finite element analysis (FEA) to validate their performance under stress during operation. The results indicated a maximum stress value of 5.35 e+06 N/m2, representing 14.5% of the intended fabrication material’s tensile strength (ABS), and the maximum deformation displacement was only 0.74 mm. The presented design and testing results pave the way for the development and use of the manipulator for future applications.

‘Are you pregnant? If not, why not?’: artificial reproductive technology and the trauma of infertility

The article scrutinises Rohini S. Rajagopal’s work, what’s a lemon squeezer doing in my vagina (2021), to illustrate the escalating medicalisation of infertile bodies. In a cultural context where reproductive...

Interventions implemented to remediate mold identified in Neonatal Intensive Care Unit (NICU) incubators, 2022 to 2023

Neonatal Intensive Care Units (NICUs) utilize incubators to sustain core temperatures associated with transepidermial water loss. High relative humidity in incubators provide an environment for fungi to grow. In August 2022, mold was identified growing in eleven (85%) NICU incubators. A team assembled to address mold in incubators. The environment was addressed as a possible source of contamination by consulting an environmental specialist. The air handler, ducts, and environment were terminally cleaned. Specimens were collected from the contaminated incubators and the manufacturer reviewed cleaning practices. Experimental trials were conducted using the incubators to replicate mold growth after interventions. The environmental consultant approved when the space could be reoccupied. Incubators introduced to the clean environment did not grow mold. Various fungi and/or yeast were identified in the contaminated incubators. Opportunities to improve cleaning and replacement of parts were identified by the manufacturer. September 2022-February 2023, seven experimental trials were completed after cleaning the incubators. Four (36%) of the eleven contaminated incubators were placed back in use due to no fungal growth. No patient illnesses occurred. The interventions implemented stopped ongoing contamination of incubators and use of previously contaminated incubators.

Study on the influence of sediment erosion of Francis turbine runner under different water heads

Abstract The average measured sediment concentration of the river section where Wanjiazhai Hydropower Station is located over the years is 5.7kg/m 3, The maximum measured sediment concentration reaches 37.6kg/m 3, The erosion of the flow components of hydraulic turbines caused by sand containing water flow is becoming increasingly severe, coupled with the frequent impact of load changes during peak shaving operation, the problems exposed during the operation of hydraulic turbines are becoming more prominent, which affects the stable operation of the units. This article uses numerical simulation and experimental testing to study the sediment wear characteristics and hydraulic performance of the water turbine at Wanjiazhai Hydropower Station. Research has revealed the effects of working head on impeller wear. The increase in working head will exacerbate the impact wear on the main channel wall of the unit. The surface of water turbine blades is the main wear area, and the high-speed impact of particles causes an increase in the wall wear rate. The probability of particles coming into contact with the wall at the outlet increases, resulting in rapid wear at this point. The increase in head will intensify the wear intensity of the unit surface, and the flow velocity in the gap indicates that the local high-speed jet in the gap is the main cause of gap wear. Therefore, in order to ensure the efficient anti-wear performance of the water turbine, multiple factors need to be comprehensively considered to cope with sediment wear of the water turbine, including regular cleaning, optimized structural design, use of wear-resistant materials, replacement of worn parts, and optimization of operating parameters. These measures help to reduce the damage of sediment wear to water turbines and extend their service life.

Influence of Printing Parameters to optimize mechanical properties in additive manufacturing – A Review

Abstract Additive manufacturing (3D printing) is a revolutionary technology with widespread applications among various industries. It is a cost effective and fast prototyping technology of 20th century, the parts produced by 3D printing are not only used for pre-production samples but also for replacement of functional parts in various applications. Various methods of 3D printing technologies viz., Fused Deposition, Resin printing etc., are available, however Fused Deposition Modelling (FDM) technique is very popular since it is promising and cost effective. There are two major aspects needs to be considered in preparing a sample from 3D printing, i.e., selection of material and printing parameter. With the advancement of material technology from time to time, the efficient and quality products that are produced with this technology. The present study explores the impact of various parameters that affect mechanical properties of 3D printed Polylactic Acid (PLA) in horizontal orientation.

A Study of the Influence of Thermoactivated Natural Zeolite on the Hydration of White Cement Mortars.

One trend in the development of building materials is the partial or complete replacement of traditional materials that have a high carbon footprint with eco-friendly ecological raw materials and ingredients. In the present work, the influence of replacing cement with 10 wt% thermally activated natural zeolite on the structural and physical-mechanical characteristics of cured mortars based on white Portland cement and river sand was investigated. The phase compositions were determined by wavelength dispersive X-ray fluorescence (WD-XRF) analysis, X-ray powder diffraction (PXRD), diffuse reflectance infrared Fourier transformed spectroscopy (DRIFTS), and scanning electron microscopy (SEM), as well as thermogravimetric analysis simultaneously with differential scanning calorimetry (TG/DTG-DSC). The results show that the incorporation of zeolite increases the amount of pores accessible with mercury intrusion porosimetry by about 40%, but the measured strengths are also higher by over 13%. When these samples were aged in an aqueous environment from day 28 to day 120, the amount of pores decreased by about 10% and the compressive strength increased by nearly 15%, respectively. The microstructural analysis carried out proves that these results are due to hydration with a low content of crystal water and the realization of pozzolanic reactions that last over time. Replacing some of the white cement with thermally activated natural zeolite results in the formation of a greater variety of crystals, including new crystalline CSH and CSAH phases that allow better intergrowth and interlocking. The results of the investigations allow us to present a plausible reaction mechanism of pozzolanic reactions and of the formation of new crystal hydrate phases. This gives grounds to claim that the replacement of part of the cement with zeolite improves the corrosion resistance of the investigated building solutions against aggressive weathering.

Development of an automated system for the purification of alkanolamine solutions

The alkanolamine solutions used in natural gas purification processes are inevitably degraded over time. This occurs due to accumulation of reaction products from the reactions with carbon dioxide, hydrogen sulphide, oxygen and other impurities present in the gas streams, as well as from thermal degradation. The degradation of solutions leads to the formation of thermostable compounds that not only reduce absorption efficiency, but also increase corrosive activity. Furthermore, part of the amine turns into a bound state and becomes ballast. The necessity of purification of alkanolamine solutions is becoming more and more urgent since the cost of maintaining efficient operation of gas treatment plants grows, and environmental safety requirements increase. Purification of solutions makes it possible to prolong their service life, reduce the cost of purchasing new reagents and reduce the negative impact on the equipment. In this work the method of anion-exchange technology of purification is used. Unlike vacuum distillation and electrodialysis, the considered technology does not require significant energy costs for generation and maintenance of vacuum, and heating of solutions, it can be easily integrated into the existing production process without any significant changes in the infrastructure. The described problem is relevant for Kazakhstan oil refineries, two of which use methyldiethanolamine, and one of which uses diethanolamine, and the existing practice of maintaining the operability of the systems is based on periodic replacement of part of the solution with pure amine. The development of automated systems for purification of such solutions makes it possible to significantly improve process control, minimise manual labour, and improve the overall economic efficiency of production.

ЧИННИКИ ТА ІНСТРУМЕНТИ ЗБЕРЕЖЕННЯ І ПІДТРИМКИ БІЗНЕСУ В УМОВАХ ВІЙНИ: ФІНАНСОВІ ТА СТРАХОВІ АСПЕКТИ

The article considers the aspects of ensuring the viability of economic entities in the critically difficult conditions of a full-scale war. As stated, in world practice, the fact of the functioning of the national economy of a country under military aggression, and even more so the preservation of the viability of economic agents, is considered paradoxical a priori. However, this has been a common practice for Ukraine for three years. The purpose of the study is to identify the factors and justify the tools of the state and corporate policy of preserving and supporting Ukrainian business in the conditions of war with the use of financial and insurance means for such purposes. Threats to the financial security of domestic economic entities in war conditions were determined by such components of security as credit, insurance, monetary, budgetary and tax, investment and fund security. Based on the same components, a policy toolkit for supporting domestic business in wartime conditions was developed, in particular in the sense of financial and insurance aspects of regulation. It was established that in the conditions of a full-scale war, the following became the dominant threats to the financial security of domestic business entities: freezing of investment projects, loss of foreign investment, destruction of facilities (investment component of financial security of enterprises); complication of attracting financial and credit resources, growth of external and internal debt, difficulty of attracting credit funds (credit component); devaluation of the national monetary unit, slowdown in the circulation of funds, difficulties in settlements with counterparties (monetary component); increase in the level of tax liabilities, decrease in the level of budget investment, delays in calculations (budget and tax component); problems of securities issuance, a decrease in the level of dividend distribution, the decline of the country’s stock system (stock component); aggravation of the problems of insurance of military risks, increase in the cost of insurance services, actualization of the problems of internal and self-insurance (insurance component). Policy instruments for strengthening the financial security of business in wartime conditions have been defined. This is the diversification of sources of investment formation, consideration of investment options abroad, however, for the production of products in the domestic market; activation of cooperation programs between enterprises to replace credit resources, optimization of internal and external debt, replacement of part of operations in foreign currency, formation of insurance and reserve funds, "decomposition" of business into separate components, detinization and legalization of business, proactive state policy in this area, use of public investment instruments, improvement of conditions for purchasing OVDP bonds, diversification of state securities, active investment policy of enterprises, improvement of war risk insurance instruments, active involvement of foreign companies to the domestic insurance market.

High speed vibration compensation using magnetic fiducials via NIMBLE

Additive manufacturing (AM) technology, specifically 3D printing, holds great promise for in-orbit manufacturing. In-space printing can significantly reduce the mass, cost, and risk of long-term space exploration by enabling replacement parts to be made as needed and reducing dependence on Earth. However, printing in a zero-gravity environment poses challenges due to the absence of a rigid ground for the print platform, which can result in vibrational and rotational forces that may impact printing integrity. To address this issue, this paper proposes a novel linear magnetic position tracking algorithm, named Navigation Integrating Magnets By Linear Estimation (NIMBLE), for dynamic vibration compensation during 3D printing of truss structures in space. Compared to the most commonly used nonlinear optimization method, the NIMBLE algorithm is more than two orders of magnitude faster. With only a single 3-axis magnet sensor and a small NdFeB magnet, the NIMBLE algorithm provides a simple and easily implemented tracking solution for in-orbit 3D printing.

ДОСРОЧНОЕ ОСВОБОЖДЕНИЕ ОСУЖДЕННОГО ОТ ОТБЫВАНИЯ НАКАЗАНИЯ В ЭКСТРЕМАЛЬНЫХ УСЛОВИЯХ: НЕКОТОРЫЕ ПРОБЛЕМЫ РЕГУЛИРОВАНИЯ

Based on the analysis of the provisions of the Federal Constitutional Law «On the State of Emergency», the Criminal Code of the Russian Federation, the Penal Code of the Russian Federation and other normative legal acts, a number of shortcomings in the regulation of parole, replacement of the unserved part of the punishment with a milder one and release from punishment due to the illness of the convicted person, accepted by the court in extreme conditions, that is, when natural disasters occur or a state of emergency or martial law is imposed. The article focuses on a number of issues: suspension of the convict’s right to apply for early release, leaving the possibility of such treatment with the administration of the institution or body executing the punishment; attribution of the convict’s participation in emergency rescue and other urgent work to the criteria for parole or replacement of the unserved part of the punishment with a milder one; imputation of post-penitentiary responsibilities related to the elimination of the consequences of extreme conditions; etc.