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14 pages, 780 KiB  
Article
Effects of Cool Water Supply on Laying Performance, Egg Quality, Rectal Temperature and Stress Hormones in Heat-Stressed Laying Hens in Open-Type Laying Houses
by Chan-Ho Kim, Woo-Do Lee, Se-Jin Lim, Ka-Young Yang and Jung-Hwan Jeon
Animals 2025, 15(11), 1635; https://doi.org/10.3390/ani15111635 - 2 Jun 2025
Viewed by 637
Abstract
We used an animal welfare-certified open-type layer farm and analyzed the egg production, egg quality, rectal temperature, and yolk corticosterone levels of laying hens supplied with cool water during the summer season (avg. 33 ± 3.89 °C). A total of 5750 Hy-Line Brown [...] Read more.
We used an animal welfare-certified open-type layer farm and analyzed the egg production, egg quality, rectal temperature, and yolk corticosterone levels of laying hens supplied with cool water during the summer season (avg. 33 ± 3.89 °C). A total of 5750 Hy-Line Brown laying hens at 53 weeks of age were used, and two treatment groups were established: a control group (2900 hens) and a cool water treatment group (2850 hens). The water temperature of the control group was 25.3 ± 0.8 °C and the cool water was 20.1 ± 0.3 °C; all other environment parameters (lighting, ventilation, temperature, feed, etc.) were the same. The experiment was conducted for a total of 9 weeks (between July and September 2024), and during this period, the temperature–humidity index (THI) inside the breeding facility averaged 85.21, which corresponds to the cool water supply range (80 < THI < 90). As a result, the cool water treatment group maintained high productivity and showed low mortality (p < 0.05). In addition, hens provided with cool water showed high eggshell strength and low yolk corticosterone levels (p < 0.05). The core finding of this study is that the supply of cool water in summer is effective in maintaining the productivity and egg quality of laying hens and reducing HS. This is significant in that it suggests it is possible to manage laying hens in summer in a simple way, and it can also be used as basic data for designing future studies, such as using a combination of natural products including vitamins and minerals. Full article
(This article belongs to the Special Issue Heat Stress Management in Poultry)
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29 pages, 3906 KiB  
Article
Efficiency-Based Modeling of Aeronautical Proton Exchange Membrane Fuel Cell Systems for Integrated Simulation Framework Applications
by Paolo Aliberti, Marco Minneci, Marco Sorrentino, Fabrizio Cuomo and Carmine Musto
Energies 2025, 18(4), 999; https://doi.org/10.3390/en18040999 - 19 Feb 2025
Cited by 4 | Viewed by 789
Abstract
Proton exchange membrane fuel cell system (PEMFCS)-based battery-hybridized turboprop regional aircraft emerge as a promising solution to the urgency of reducing the environmental impact of such airplanes. The development of integrated simulation frameworks consisting of versatile and easily adaptable models and control strategies [...] Read more.
Proton exchange membrane fuel cell system (PEMFCS)-based battery-hybridized turboprop regional aircraft emerge as a promising solution to the urgency of reducing the environmental impact of such airplanes. The development of integrated simulation frameworks consisting of versatile and easily adaptable models and control strategies is deemed highly strategic to guarantee proper component sizing and in-flight, onboard energy management. This need is here addressed via a novel efficiency-driven PEMFCS model and a degradation-aware battery-PEMFCS unit specification-independent control algorithm. The proposed model simplifies stack voltage and current estimation while maintaining accuracy so as to support, in conjunction with the afore-introduced versatile control strategy, the development of architectures appropriate for subsequent fully integrated (i.e., at the entire aircraft design level) simulation frameworks. The model also allows assessing the balance of plant impact on the fuel cell system’s net power, as well as the heat generated by the stack and related cooling demand. Finally, the multi-stack configuration meeting the DC bus line 270 V constraint, as currently assumed by the aviation industry, is determined. Full article
(This article belongs to the Section D: Energy Storage and Application)
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15 pages, 5550 KiB  
Article
Microstructure of Neutron-Irradiated Al3Hf-Al Thermal Neutron Absorber Materials
by Donna Post Guillen, Janelle Wharry, Yu Lu, Michael Wu, Jeremy Sharapov and Matthew Anderson
Materials 2025, 18(4), 833; https://doi.org/10.3390/ma18040833 - 14 Feb 2025
Cited by 1 | Viewed by 1097
Abstract
A thermal neutron-absorbing metal matrix composite (MMC) comprised of Al3Hf particles in an aluminum matrix was developed to filter out thermal neutrons and create a fast flux environment for material testing in a mixed-spectrum nuclear reactor. Intermetallic Al3Hf particles [...] Read more.
A thermal neutron-absorbing metal matrix composite (MMC) comprised of Al3Hf particles in an aluminum matrix was developed to filter out thermal neutrons and create a fast flux environment for material testing in a mixed-spectrum nuclear reactor. Intermetallic Al3Hf particles capture thermal neutrons and are embedded in a highly conductive aluminum matrix that provides conductive cooling of the heat generated due to thermal neutron capture by the hafnium. These Al3Hf-Al MMCs were fabricated using powder metallurgy via hot pressing. The specimens were neutron-irradiated to between 1.12 and 5.38 dpa and temperatures ranging from 286 °C to 400 °C. The post-irradiation examination included microstructure characterization using transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy. This study reports the microstructural observations of four irradiated samples and one unirradiated control sample. All the samples showed the presence of oxide at the particle–matrix interface. The irradiated specimens revealed needle-like structures that extended from the surface of the Al3Hf particles into the Al matrix. An automated segmentation tool was implemented based on a YOLO11 computer vision-based approach to identify dislocation lines and loops in TEM images of the irradiated Al-Al3Hf MMCs. This work provides insight into the microstructural stability of Al3Hf-Al MMCs under irradiation, supporting their consideration as a novel neutron absorber that enables advanced spectral tailoring. Full article
(This article belongs to the Special Issue Advanced Characterization Techniques on Nuclear Fuels and Materials)
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14 pages, 3783 KiB  
Article
Modeling and Estimation of the Pitch Angle for a Levitating Cart in a UAV Magnetic Catapult Under Stationary Conditions
by Edyta Ładyżyńska-Kozdraś, Bartosz Czaja, Sławomir Czubaj, Jan Tracz, Anna Sibilska-Mroziewicz and Leszek Baranowski
Electronics 2025, 14(1), 44; https://doi.org/10.3390/electronics14010044 - 26 Dec 2024
Viewed by 801
Abstract
The paper presents a method for modeling and estimating the orientation of a launch cart in the magnetic suspension system of an innovative UAV catapult. The catapult consists of stationary tracks lined with neodymium magnets, generating a trough-shaped magnetic field. The cart levitates [...] Read more.
The paper presents a method for modeling and estimating the orientation of a launch cart in the magnetic suspension system of an innovative UAV catapult. The catapult consists of stationary tracks lined with neodymium magnets, generating a trough-shaped magnetic field. The cart levitates above the tracks, supported by four containers housing high-temperature YBCO superconductors cooled with liquid nitrogen. The Meissner effect, characterized by the expulsion of magnetic fields from superconductors, ensures stable hovering of the cart. The main research challenge was to determine the cart’s orientation relative to the tracks, with a focus on the pitch angle, which is critical for collision-free operation and system efficiency. A dedicated measurement stand equipped with Hall sensors and Time-of-Flight (ToF) distance sensors was developed. Hall sensors mounted on the cart’s supports captured magnetic field data at specific points. To model the tracks, the CRISP-DM (Cross Industry Standard Process for Data Mining) methodology was employed—a structured framework consisting of six stages; from problem understanding and data preparation to model evaluation and deployment. This approach guided the analysis of data-driven models and facilitated accurate pitch angle estimation. Evaluation metrics, including mean squared error (MSE), were used to identify and select the optimal models. The final model achieved an MSE of 0.084°, demonstrating its effectiveness for precise orientation control. Full article
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20 pages, 8284 KiB  
Article
Development of a Low-Cost Automated Demand Response Controller for Home Energy Management
by Yu-Chi Wu, Chao-Shu Chang and Wei-Han Li
Appl. Sci. 2024, 14(23), 11434; https://doi.org/10.3390/app142311434 - 9 Dec 2024
Viewed by 1303
Abstract
This research focuses on developing a low-cost automated demand response controller (DRC) with OpenADR 2.0a capability to enable existing infrared-controlled (IR-controlled) air conditioners (ACs) in homes and buildings to participate in automated demand response programs (ADRPs). The DRC consists of four modules: a [...] Read more.
This research focuses on developing a low-cost automated demand response controller (DRC) with OpenADR 2.0a capability to enable existing infrared-controlled (IR-controlled) air conditioners (ACs) in homes and buildings to participate in automated demand response programs (ADRPs). The DRC consists of four modules: a smart socket module, an infrared module, a temperature sensor, and a voltage/current module. It can receive, analyze, and respond to demand response (DR) events and perform necessary demand and energy control strategies via IR. Power line communication (PLC) is used for communication without additional wiring. The system is tested under two conditions: participating in ADRPs via OpenADR and not participating in ADRPs. An 8.8% load reduction is observed with different temperature settings when not participating in ADRPs, and energy reductions of 21% to 46% are achieved using various cooling/fanning duty cycles in ADRPs. The proposed system can be integrated with any DR algorithm to meet demand management requirements under the OpenADR program, contributing to significant demand reductions. Full article
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14 pages, 2329 KiB  
Article
PSO-FDM (Particle Swarm Optimization-Finite Difference Method)-Based Simulation Model of Temperature and Velocity of Full-Scale Continuous Annealing Furnace
by Yang Liu, Qiang Guo, Tieheng Yuan, Yingrui Han, Chao Liu and Wenquan Sun
Metals 2024, 14(11), 1204; https://doi.org/10.3390/met14111204 - 23 Oct 2024
Viewed by 1044
Abstract
Improving the accuracy of the temperature field prediction model for continuous annealing line strips and enhancing the model’s adaptability to full-size strips are key technical challenges in continuous annealing lines. This paper developed a continuous annealing temperature prediction model based on a variable [...] Read more.
Improving the accuracy of the temperature field prediction model for continuous annealing line strips and enhancing the model’s adaptability to full-size strips are key technical challenges in continuous annealing lines. This paper developed a continuous annealing temperature prediction model based on a variable step-size strategy for the heating section, even-heat section, slow-cooling section, and fast-cooling section of the continuous annealing line. To improve the prediction accuracy for different strip sizes, the PSO optimization algorithm was employed to determine the optimal heat transfer coefficient for each strip size. Additionally, due to the limited production of certain strip gauges, providing insufficient data for optimization, this study introduces a combined file approach to address gauge vacancies. The experimental results indicate that the optimized model with variable step size can control the absolute prediction error to less than 4 °C, improving prediction accuracy by 61.9% and prediction speed by 26.8% compared to the traditional equal-step prediction model. This study verified that the merger method is effective for addressing side gauge vacancies, while the proposed method is suitable for resolving middle gauge vacancies. The main technical contribution of this study is the establishment of a high-precision prediction model for continuous annealing temperature of variable step length strips, ensuring high temperature control accuracy for full-gauge strips when passing through the continuous annealing production line. Full article
(This article belongs to the Section Metal Casting, Forming and Heat Treatment)
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27 pages, 5811 KiB  
Article
Advanced Study: Improving the Quality of Cooling Water Towers’ Conductivity Using a Fuzzy PID Control Model
by You-Shyang Chen, Ying-Hsun Hung, Mike Yau-Jung Lee, Jieh-Ren Chang, Chien-Ku Lin and Tai-Wen Wang
Mathematics 2024, 12(20), 3296; https://doi.org/10.3390/math12203296 - 21 Oct 2024
Cited by 2 | Viewed by 1789
Abstract
Cooling water towers are commonly used in industrial and commercial applications. Industrial sites frequently have harsh environments, with certain characteristics such as poor air quality, close proximity to the ocean, large quantities of dust, or water supplies with a high mineral content. In [...] Read more.
Cooling water towers are commonly used in industrial and commercial applications. Industrial sites frequently have harsh environments, with certain characteristics such as poor air quality, close proximity to the ocean, large quantities of dust, or water supplies with a high mineral content. In such environments, the quality of electrical conductivity in the cooling water towers can be significantly negatively affected. Once minerals (e.g., calcium and magnesium) form in the water, conductivity becomes too high, and cooling water towers can become easily clogged in a short time; this leads to a situation in which the cooling water host cannot be cooled, causing it to crash. This is a serious situation because manufacturing processes are then completely shut down, and production yield is thus severely reduced. To solve these problems, in this study, we develop a practical designation for a photovoltaic industry company called Company-L. Three control methods are proposed: the motor control method, the PID control method, and the fuzzy PID control method. These approaches are proposed as solutions for successfully controlling the forced replenishment and drainage of cooling water towers and controlling the opening of proportional control valves for water release; this will further dilute the electrical conductivity and control it, bringing it to 300 µS/cm. In the experimental processes, we first used practical data from Company-L for our case study. Second, from the experimental results of the proposed model for the motor control method, we can see that if electrical conductivity is out of control and the conductivity value exceeds 1000 µS/cm, the communication software LINE v8.5.0 (accessible via smartphone) displays a notification that the water quality of the cooling water towers requires attention. Third, although the PID control method is shown to have errors within an acceptable range, the proportional (P) controller must be precisely controlled; this control method has not yet reached this precise control in the present study. Finally, the fuzzy PID control method was found to have the greatest effect, with the lowest level of errors and the most accurate control. In conclusion, the present study proposes solutions to reduce the risk of ice-water host machines crashing; the solutions use fuzzy logic and can be used to ensure the smooth operation of manufacturing processes in industries. Practically, this study contributes an applicable technical innovation: the use of the fuzzy PID control model to control cooling water towers in industrial applications. Concurrently, we present a three-tier monitoring checkpoint that contributes to the PID control method. Full article
(This article belongs to the Special Issue Fuzzy Applications in Industrial Engineering, 3rd Edition)
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16 pages, 2211 KiB  
Article
Multiple Localization Analysis of the Major QTL—sfw 2.2 for Controlling Single Fruit Weight Traits in Melon Based on SLAF Sequencing
by Yi Cai, Di Wang, Ye Che, Ling Wang, Fan Zhang, Tai Liu and Yunyan Sheng
Genes 2024, 15(9), 1138; https://doi.org/10.3390/genes15091138 - 28 Aug 2024
Cited by 1 | Viewed by 1199
Abstract
Cucumis melo is an annual dicotyledonous trailing herb. It is fruity, cool, and refreshing to eat and is widely loved by consumers worldwide. The single fruit weight is an important factor affecting the yield, and thus the income and economic benefits, of melon [...] Read more.
Cucumis melo is an annual dicotyledonous trailing herb. It is fruity, cool, and refreshing to eat and is widely loved by consumers worldwide. The single fruit weight is an important factor affecting the yield, and thus the income and economic benefits, of melon crops. In this study, to identify the main QTLs (quantitative trait locus) controlling the single fruit weight of melon and thereby identify candidate genes controlling this trait, specific-locus amplified fragment sequencing (SLAF) analysis was performed on the offspring of female 1244 plants crossed with male MS-5 plants. A total of 115 individual plants in the melon F2 population were analyzed to construct a genetic linkage map with a total map distance of 1383.88 cM by the group in the early stages of the project, which was divided into 12 linkage groups with a total of 10,596 SLAF markers spaced at an average genetic distance of 0.13 cM. A total of six QTLs controlling single fruit weight (sfw loci) were detected. Seven pairs of markers with polymorphisms were obtained by screening candidate intervals from the SLAF data. The primary QTL sfw2.2 was further studied in 300 F2:3 family lines grown in 2020 and 2021, respectively, a positioning sfw2.2 between the markers CY Indel 11 and CY Indel 16, between 18,568,142 and 18,704,724 on chromosome 2. This interval contained 136.58 kb and included three genes with functional annotations, MELO3C029673, MELO3C029669, and MELO3C029674. Gene expression information for different fruit development stages was obtained from 1244 and MS-5 fruits on the 15d, 25d, and 35d after pollination, and qRT-PCR (quantitative reverse transcription–PCR) indicated that the expression of the MELO3C029669 gene significantly differed between the parents during the three periods. The gene sequences between the parents of MELO3C029669 were analyzed and compared, a base mutation was found to occur in the intronic interval between the parents of the gene, from A-G. Phylogenetic evolutionary tree analysis revealed that the candidate gene MELO3C029669 is most closely related to Pisum sativum Fimbrin-5 variant 2 and most distantly related to Cucumis melo var. makuwa. Therefore, it was hypothesized that MELO3C029669 is the primary major locus controlling single fruit weight in melon. These results not only provide a theoretical basis for further studies to find genes with functions in melon single fruit weight but also lay the foundation for accelerating breakthroughs and innovations in melon breeding. Full article
(This article belongs to the Section Plant Genetics and Genomics)
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20 pages, 4918 KiB  
Article
Influence of Extrusion Parameters on the Mechanical Properties of Slow Crystallizing Carbon Fiber-Reinforced PAEK in Large Format Additive Manufacturing
by Patrick Consul, Matthias Feuchtgruber, Bernhard Bauer and Klaus Drechsler
Polymers 2024, 16(16), 2364; https://doi.org/10.3390/polym16162364 - 21 Aug 2024
Cited by 3 | Viewed by 1503
Abstract
Additive Manufacturing (AM) enables the automated production of complex geometries with low waste and lead time, notably through Material Extrusion (MEX). This study explores Large Format Additive Manufacturing (LFAM) with carbon fiber-reinforced polyaryletherketones (PAEK), particularly a slow crystallizing grade by Victrex. The research [...] Read more.
Additive Manufacturing (AM) enables the automated production of complex geometries with low waste and lead time, notably through Material Extrusion (MEX). This study explores Large Format Additive Manufacturing (LFAM) with carbon fiber-reinforced polyaryletherketones (PAEK), particularly a slow crystallizing grade by Victrex. The research investigates how extrusion parameters affect the mechanical properties of the printed parts. Key parameters include line width, layer height, layer time, and extrusion temperature, analyzed through a series of controlled experiments. Thermal history during printing, including cooling rates and substrate temperatures, was monitored using thermocouples and infrared cameras. The crystallization behavior of PAEK was replicated in a Differential Scanning Calorimetry (DSC) setup. Mechanical properties were evaluated using three-point bending tests to analyze the impact of thermal conditions at the deposition interface on interlayer bonding and overall part strength. The study suggests aggregated metrics, enthalpy deposition rate and shear rate under the nozzle, that should be maximized to enhance mechanical performance. The findings show that the common practice of setting fixed layer times falls short of ensuring repeatable part quality. Full article
(This article belongs to the Topic Advanced Composites Manufacturing and Plastics Processing)
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12 pages, 1519 KiB  
Article
Effects of Different Diluents and Freezing Methods on Cryopreservation of Hu Ram Semen
by Liuming Zhang, Xuyang Wang, Caiyu Jiang, Tariq Sohail, Yuxuan Sun, Xiaomei Sun, Jian Wang and Yongjun Li
Vet. Sci. 2024, 11(6), 251; https://doi.org/10.3390/vetsci11060251 - 3 Jun 2024
Cited by 3 | Viewed by 2225
Abstract
The purpose of this study was to investigate the effects of different diluents and freezing methods on the quality of thawed sperm after cryopreservation and find an inexpensive and practical method for freezing Hu ram semen for use in inseminations under farm conditions. [...] Read more.
The purpose of this study was to investigate the effects of different diluents and freezing methods on the quality of thawed sperm after cryopreservation and find an inexpensive and practical method for freezing Hu ram semen for use in inseminations under farm conditions. Ejaculates were collected from five Hu rams. In experiment I, ejaculates were diluted with eight different freezing diluents (basic diluents A, B, C, D, E, F, G, and H). After dilution and cooling, the samples were loaded into 0.25 mL straws and frozen using the liquid nitrogen fumigation method. In experiment II, diluent C was used as the basic diluent and the semen was frozen using liquid nitrogen fumigation and two program-controlled cooling methods. For analysis, frozen samples were evaluated in terms of motility parameters (total motility (TM), progressive motility (PM)), biokinetic characteristics (straight-line velocity (VSL), average path velocity (VAP), curvilinear velocity (VCL), amplitude of lateral head displacement (ALH), wobble movement coefficient (WOB), average motion degree (MAD)), reactive oxygen species (ROS) level, and membrane and acrosome integrity. In experiment I, diluent C had higher TM, PM, and acrosome and membrane integrity and lower ROS compared to other extenders (p < 0.05) except diluent A. Diluent C exhibited higher (p < 0.05) VCL, VAP, ALH, WOB, and MAD compared to diluents B, D, E, and F. In experiment II, TM and all biokinetic characteristics did not show significant differences (p > 0.05) amongst the three freezing methods. Liquid nitrogen fumigation resulted in higher (p < 0.05) PM, membrane integrity, acrosome integrity, and lower ROS level compared to the program. In conclusion, the thawed semen diluted with diluent C had higher quality compared to other diluents. The liquid nitrogen fumigation demonstrated superior semen cryopreservation effects compared to the program-controlled cooling method using diluent C. Full article
(This article belongs to the Special Issue Advances in Animal Sperm Conservation Techniques for Better Fertility)
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19 pages, 7225 KiB  
Article
Exploring the Dynamics of Land Surface Temperature in Jordan’s Local Climate Zones: A Comprehensive Assessment through Landsat Entire Archive and Google Earth Engine
by Khaled Hazaymeh, Mohammad Zeitoun, Ali Almagbile and Areej Al Refaee
Atmosphere 2024, 15(3), 318; https://doi.org/10.3390/atmos15030318 - 4 Mar 2024
Cited by 1 | Viewed by 1896
Abstract
This study aimed to analyze the trend in land surface temperature (LST) over time using the entire archive of the available cloud-free Landsat images from 1986 to 2022 for Jordan and its nine local climate zones (LCZs). Two primary datasets were used (i) [...] Read more.
This study aimed to analyze the trend in land surface temperature (LST) over time using the entire archive of the available cloud-free Landsat images from 1986 to 2022 for Jordan and its nine local climate zones (LCZs). Two primary datasets were used (i) Landsat-5; -8 imagery, and (ii) map of LCZs of Jordan. All LST images were clipped, preprocessed, and checked for cloud contamination and bad pixels using the quality control bands. Then, time-series of monthly LST images were generated through compositing and mosaicking processes using cloud computing functions and Java scripts in Google Earth Engine (GEE). The Mann–Kendall (MK) test and Sen’s slope estimator (SSE) were used to detect and quantify the magnitude of LST trends. Results showed a warming trend in the maximum LST values for all LCZs while there was annual fluctuation in the trend line of the minimum LST values in the nine zones. The monthly average LST values showed a consistent upward trajectory, indicating a warming condition, but with variations in the magnitude. The annual rate of change in LST for the LCZs showed that the three Saharan zones are experiencing the highest rate of increase at 0.0184 K/year for Saharan Mediterranean Warm (SMW), 0.0185 K/year for Saharan Mediterranean Cool (SMC), and 0.0169 K/year for Saharan Mediterranean very Warm (SMvW), indicating rapid warming in these regions. The three arid zones came in the middle, with values of 0.0156 K/year for Arid Mediterranean Warm (AMW), 0.0151 for Arid Mediterranean very Warm (AMvW), and 0.0139 for Arid Mediterranean Cool (AMC), suggesting a slower warming trend. The two semi-arid zones and the sub-humid zone showed lower values at 0.0138, 0.0127, and 0.0117 K/year for the Semi-arid Mediterranean Cool (SaMC), Semi-arid Mediterranean Warm (SaMW) zones, and Semi-humid Mediterranean (ShM) zones, respectively, suggesting the lowest rate of change compared to other zones. These findings would provide an overall understanding of LST change and its impact in Jordan’s LCZs for sustainable development and water resources demand and management. Full article
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25 pages, 16651 KiB  
Article
Analysis of the Uniformity of Mechanical Properties along the Length of Wire Rod Designed for Further Cold Plastic Working Processes for Selected Parameters of Thermoplastic Processing
by Konrad Błażej Laber
Materials 2024, 17(4), 905; https://doi.org/10.3390/ma17040905 - 15 Feb 2024
Cited by 1 | Viewed by 1772
Abstract
This study presents the results of research, the aim of which was to analyze the uniformity of the distribution of selected mechanical properties along the length of a 5.5 mm diameter wire rod of 20MnB4 steel for specific thermoplastic processing parameters. The scope [...] Read more.
This study presents the results of research, the aim of which was to analyze the uniformity of the distribution of selected mechanical properties along the length of a 5.5 mm diameter wire rod of 20MnB4 steel for specific thermoplastic processing parameters. The scope of the study included, inter alia, metallographic analyses, microhardness tests, thermovision investigations, and tests of the wire rod mechanical properties (yield strength, ultimate tensile strength, elongation, relative reduction in area at fracture), along with their statistical analysis, for three technological variants of the rolling process differing by rolling temperature in the final stage of the rolling process (Reducing Sizing Mill rolling block [RSM]) and by cooling rate using STELMOR® cooling process. The obtained results led to the conclusion that the analyzed rolling process is characterized by a certain disparity of the analyzed mechanical properties along the length of the wire rod, which, however, retains a certain stability. This disparateness is caused by a number of factors. One of them, which ultimately determines the properties of the finished wire rod, is the process of controlled cooling in the STELMOR® line. Despite technological advances concerning technical solutions (among them, increasing the roller track speed in particular sections), it is currently not possible to completely eliminate the temperature difference along the length of the wire rod caused by the contact of individual coils with each other. From this point of view, for the analyzed thermoplastic processing parameters, there is no significant impact by the production process parameters on the quality of the finished steel product. Whereas, while comparing the mechanical properties and microstructure of the wire rod produced in the different technological combinations, it was found that the wire rod rolled in an RSM block at 850 °C and cooled after the rolling process on a roller conveyor at 10 °C/s had the best set of mechanical properties and the smallest microstructure variations. The wire rod produced in this way had the required level of plasticity reserve, which enables further deformation of the given type of steel in compression tests with a relative plastic strain of 75%. The uniformity of mechanical properties along the length of wire rods designed for further cold plastic working processes is an important problem. This is an important issue, given that wire rods made from 20MnB4 steel are an input material for further cold plastic working processes, e.g., for the drawing processes or the production of nails. Full article
(This article belongs to the Special Issue Metalworking Processes: Theoretical and Experimental Study)
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25 pages, 9757 KiB  
Article
Redesign of a Disc-on-Disc Computer Numerical Control Tribometer for a Wide-Range and Shudder-Resistant Operation
by Matija Hoić, Mario Hrgetić, Nenad Kranjčević, Joško Deur and Andreas Tissot
Machines 2024, 12(1), 14; https://doi.org/10.3390/machines12010014 - 26 Dec 2023
Cited by 1 | Viewed by 1809
Abstract
The paper presents a redesign of the custom disc-on-disc-type tribometer intended for the experimental characterization of the friction and wear of automotive dry clutch friction lining. The redesign is aimed at expanding the operating range at which the machine is not sensitive to [...] Read more.
The paper presents a redesign of the custom disc-on-disc-type tribometer intended for the experimental characterization of the friction and wear of automotive dry clutch friction lining. The redesign is aimed at expanding the operating range at which the machine is not sensitive to shudder vibrations. This is achieved through a set of hardware and software upgrade measures. First, the natural frequency of the normal load-generation linear axis of the machine is increased by enlarging its bending stiffness and reducing the suspended mass. The former is realized by replacing the single, two-axial force/torque piezoelectric sensor with a set of three three-axial piezoelectric force sensors, adding a set of stiff linear guides, and reducing the lengths of the cantilevers of lateral forces acting on the linear axis guide system. The latter is accomplished by reducing the overall dimensions of the cooling disc and redesigning the thermal insulation components. The shudder sensitivity resistance is further reduced through individual normal force-readings-based adjustment of parallelism between friction contact surfaces and the increase in the stiffness of eccentrically positioned water-cooling pipes. Finally, the stability of the coefficient of friction and, consequently, the wear process are boosted by adjusting the control routines to minimize the circumferential and/or radial temperature gradients. These adjustments include the introduction of a clutch lock-up interval at the end of the clutch closing cycle, a minimum cooling delay inserted between two closing cycles, and maximum normal force demand of the clutch torque controller. The performance gain of the upgraded tribometer is demonstrated through a study of the dry clutch friction plate static wear experimental characterization for a wide range of operating conditions. Full article
(This article belongs to the Special Issue Advances in Vehicle Brake and Clutch Systems)
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17 pages, 13330 KiB  
Article
Investigation of the Dislocation Density of NiCr Coatings Prepared Using PVD–LMM Technology
by Guoqing Song, Wentian Wei, Bincai Shuai, Botao Liu and Yong Chen
Materials 2023, 16(22), 7234; https://doi.org/10.3390/ma16227234 - 20 Nov 2023
Viewed by 1622
Abstract
Micron-sized coatings prepared using physical vapor deposition (PVD) technology can peel off in extreme environments because of their low adhesion. Laser micro-melting (LMM) technology can improve the properties of the fabricated integrated material due to its metallurgical combinations. However, the microstructural changes induced [...] Read more.
Micron-sized coatings prepared using physical vapor deposition (PVD) technology can peel off in extreme environments because of their low adhesion. Laser micro-melting (LMM) technology can improve the properties of the fabricated integrated material due to its metallurgical combinations. However, the microstructural changes induced by the high-energy laser beam during the LMM process have not been investigated. In this study, we used the PVD–LMM technique to prepare NiCr coatings with a controlled thickness. The microstructural changes in the NiCr alloy coatings during melting and cooling crystallization were analyzed using molecular dynamics simulations. The simulation results demonstrated that the transition range of the atoms in the LMM process fluctuated synchronously with the temperature, and the hexagonal close-packed (HCP) structure increased. After the cooling crystallization, the perfect dislocations of the face-centered cubic (FCC) structure decreased significantly. The dislocation lines were mainly 1/6 <112> imperfect dislocations, and the dislocation density increased by 107.7%. The dislocations in the twinning region were affected by the twin boundaries and slip surfaces. They were plugged in their vicinity, resulting in a considerably higher dislocation density than in the other regions, and the material hardness increased significantly. This new technique may be important for the technological improvement of protective coatings on Zr alloy surfaces. Full article
(This article belongs to the Special Issue Advanced Materials Processing for Engineering Applications)
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23 pages, 15007 KiB  
Article
Effect of High Temperature and Thermal Cycle of 4043 Al Alloy Manufactured through Continuous Casting Direct Rolling
by Bo-Chin Huang and Fei-Yi Hung
Materials 2023, 16(22), 7176; https://doi.org/10.3390/ma16227176 - 15 Nov 2023
Cited by 6 | Viewed by 2025
Abstract
CCDR 4043 Al alloys are an outstanding candidate for producing mechanical components for automotive or aircraft engines. Two experimental environments—sustained high temperature and repeated heating–cooling—were simulated in the laboratory to replicate the actual operating conditions of engine components. This research investigated the microstructural [...] Read more.
CCDR 4043 Al alloys are an outstanding candidate for producing mechanical components for automotive or aircraft engines. Two experimental environments—sustained high temperature and repeated heating–cooling—were simulated in the laboratory to replicate the actual operating conditions of engine components. This research investigated the microstructural evolution, mechanical properties, and fracture characteristics of the 4043 Al alloy manufactured through the continuous casting direct rolling (CCDR) process under different post-processing conditions. The CCDR process combines continuous casting, billet heating, and subsequent continuous rolling in a single equipment of production line, enabling the mass production of Al alloy in a cost-effective and energy-efficient manner. In the present work, the 4043 alloy was subjected to two environmental conditions: a sustained high-temperature environment (control group) and a cyclic heating–cooling environment (experimental group). The maximum temperature was set to 200 °C in the experiment. The experimental results show that, in a sustained high temperature working environment, the strength and elongation of the CCDR 4043 Al alloy tend to be stable. The overall effect involves the Al matrix softening and the spheroidization of eutectic Si caused by prolonged exposure to high temperature. This can enhance its ductility while retaining a certain level of mechanical strength. Comparatively, in the working environment of cyclic heating–cooling (thermal cycle), the direction of Si diffusion was different in each cycle, thus leading to the formation of an irregular Ai–Si eutectic structure containing precipitated Si particles of different sizes. The two compositions of Al and Si with very different thermal expansion coefficients may induce defects at the sharp points of Si particles under repeated heating–cooling, thereby reducing the strength and ductility of the material. The results of this work can confirm that the fracture behavior of 4043 Al alloys is obviously controlled by the morphology of the precipitated eutectic Si. In addition, CCDR 4043 Al alloys are not suitable to be used in working environments with a thermal cycle. In practical applications, it is necessary to add traces of special elements or to employ other methods to achieve the purpose of spheroidizing the precipitated eutectic Si and Al–Fe–Si phases to avoid the deterioration of strength and ductility under cyclic heating. To date, no other literature has explored the changes in the microstructure and mechanical properties of CCDR 4043 Al alloys across various time scales under the aforementioned working environments. In summary, the findings provide valuable insights into the effect of thermal conditions on the properties and behavior of CCDR 4043 Al alloys, offering potential applications for it in various engineering fields, such as the automotive and aerospace industries. Full article
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