Thermal Oxidative Aging and Service Life Prediction of Commercial Ethylene-Propylene-Diene Monomer Spacer Damping Composites for High-Voltage Transmission Lines.

The aging behavior and life prediction of rubber composites are crucial for ensuring high-voltage transmission line safety. In this study, commercially available ethylene-propylene-diene monomer (EPDM) spacer composites were chosen and investigated to elucidate the structure and performance changes under various aging conditions. The results showed an increased C=O peak intensity with increasing aging time, suggesting intensified oxidation of ethylene and propylene units. Furthermore, the surface morphology of commercial EPDM composites displayed increased roughness and aggregation after aging. Furthermore, hardness, modulus at 100% elongation, and tensile strength of commercial EPDM composites exhibited a general increase, while elongation at break decreased. Additionally, the damping performance decreased significantly after aging, with a 20.6% reduction in loss factor (20 °C) after aging at 100 °C for 672 h. With increasing aging time and temperature, the compression set gradually rose due to the irreversible movement of the rubber chains under stress. A life prediction model was developed based on a compression set to estimate the lifetime of rubber composites for spacer bars. The results showed that the product's life was 8.4 years at 20 °C. Therefore, the establishment of a life prediction model for rubber composites can provide valuable technical support for spacer product services.

Solid-state fermentation using wheat bran to produce glucose syrup and functional cereal bars.

Wheat bran is one of the most abundant by-products from grain milling, which can be used as substrate for solid-state fermentation (SSF) to obtain enzymes able to convert this agro-industrial waste into glucose syrup, which in turn can be applied for the production of different food products. The present study aimed to determine centesimal composition of wheat bran, obtain enzymatic extract that converts wheat bran into wheat glucose syrup (WGS), produce rice flakes cereal bars (RFCB), and evaluate their nutritional composition and the presence of functional compounds, as well as their antioxidant potential. Determination of centesimal composition of wheat bran demonstrated its nutritional potential. Enzymatic extract was obtained and it converted wheat bran into WGS, which were applied to rice flakes producing RFCB. These cereal bars proved to be a source of dietary fiber (1.8 g) and soluble protein (7.2 g) while RCFB produced with corn glucose syrup did not present these nutritional components. In addition, RFCB produced with WGS showed polyphenolic compounds, among them flavonoids, which exhibited antioxidant activity by DPPH and ABTS radical scavenging (47.46% and 711.89 µM Trolox Equivalent/g, respectively), and iron ion reduction (71.70 µM Trolox equivalent/g). Final product showed a decrease in caloric value and sodium content. Therefore, the present study showed that the bioprocess of SSF yields a nutritional, ecological, and functional food product, which might be of great interest for food industry, adding nutritional and functional value to a well-stablished product.

Comparison of Fracture Behavior in Single-Edge Notched Beams Reinforced with Steel Bars or CFRP Bars.

To explore and compare the failure modes, deformation behaviors, and load-bearing capacities of single-edge notched (SEN) beams strengthened with carbon fiber-reinforced polymer (CFRP) and steel bars, static and dynamic three-point bending tests on both types of concrete beams have been carried out in this study. During the static tests, the electro-hydraulic servo machine served as a loading device to apply pressure to CFRP beams and reinforced concrete (RC) beams. During the impact experiments, different impact velocities were imparted by adjusting the drop hammer's height. Thus, information regarding crack propagation, energy absorption, and deformation was obtained. The results from the static tests showed that the RC beams predominantly experienced shear failure. In contrast, the CFRP beams primarily exhibited bending-shear failure, attributed to the relatively weaker bond strength between the bars and the concrete. Impact tests were conducted at three different velocities in this study. As the impact velocity increased, both types of concrete beams transitioned from bending failure to bending-shear failure. At the lowest velocity, the difference in energy absorption between beams reinforced with different materials was insignificant during the bending process. However, at the highest velocity, CFRP beams absorbed less energy than RC beams. The study of structures' impact failure modes and their mechanical characteristics offers valuable references for the anti-collision design and protection of structures.

Intake of Snacks and Sweets in a National Study of Built and Social Environments: The REasons for Geographic And Racial Differences in Stroke Study.

BACKGROUND: Few national studies across the United States' rural-urban continuum examine neighborhood effects on snacks and sweets intake among adults. OBJECTIVE: This study examines associations of urbanicity/rurality-tailored measures of food store availability and neighborhood socioeconomic status (NSES) with the intake of snacks and sweets in a national sample of middle and older age adults. METHODS: This cross-sectional study used food frequency questionnaire data collected in the REasons for Geographic And Racial Differences in Stroke study (N=21,204). What We Eat in America food group categorizations guided outcome classification into one main category (total snacks and sweets) and four subcategories (savory snacks and crackers; sweet bakery products; candy and desserts; nutrition bars and low-fat snacks and sweets). NSES and food store availability were determined using geographic information systems. Food store availability was characterized as geographic access to primary food stores (e.g., supermarkets, supercenters, and select food retailers) in urbanicity/rurality-tailored neighborhood-based buffers. Multiple linear regression was used to predict each outcome. RESULTS: Living in neighborhoods with a high density of primary food stores was associated with 8.6%, 9.5%, and 5.8% lower intake of total snacks and sweets, sweet bakery products, and candy and desserts, respectively. Living in the highest NSES quartile was associated with 11.3%, 5.8%, and 18.9% lower intake of total snacks and sweets, savory snacks and crackers, and sweet bakery products, respectively. Depending on primary food store availability, higher household income was associated with significantly greater intake of nutrition bars and low-fat snacks and sweets. Living in a USDA-defined food desert was not associated with intake. CONCLUSIONS: In a geographically diverse sample of middle and older age US adults, living in neighborhoods with no primary food stores or neighborhoods of low SES was associated with higher intake of total snacks and sweets and subgroups of snacks and sweets.

Malondialdehyde levels and bioaccessibility in healthy diet bars: A gastrointestinal digestion model.

Malondialdehyde (MDA), which is composed when n-6 and n-3 PUFAs are peroxidized, has been utilized as an indicator of lipid peroxidation and has been considered neurotoxic, cytotoxic, and mutagenic. This study aimed to determine the bioaccessibility level of MDA in diet bars sold as healthy snacks in the market using in vitro gastrointestinal digestive model. In our study, 28 different diet bar samples were bought from markets in Istanbul. MDA contents of the products were determined by the HPLC-FLD method. The investigation showed that diet bars had an average MDA concentration of 116.25 µg/100 g before digestion, while the average MDA concentration was 90.50 µg/100 g after in vitro digestion. In line with these data, the average MDA bioaccessibility of 28 diet bar samples was calculated as 77.3%. For this reason, more studies are needed to understand the relationship between both the MDA content and the reaction and nutritional components.

Inclusion of reeling wastewater-derived sericin peptides in high-protein nutrition bars for antihardening and storage stability.

The utilization of agroindustrial wastes to enrich food protein resources and the exploration of their broader applications are crucial for addressing the food crisis and achieving sustainable development goals. In this study, reeling wastewater-derived sericin was hydrolyzed using papain and trypsin to prepare sericin peptide (SRP) and was used as an antihardening ingredient of high-protein nutrition bars (HPNBs). The mechanism of the antihardening effect of SRP was elucidated by investigating the content of advanced glycation end products and protein oxidation products (carbonyl and free sulfhydryl), and the molecular weight change of HPNBs during storage before and after the addition of SRP. Our results confirmed the fortification of HPNBs with SRP, which is beneficial for the promotion and expansion of sericin applications in the food industry, with positive implications for the rational utilization of protein resources and the enrichment of food protein sources.

Study on the Bonding Performance of BFRP Bars with Seawater Sand Concrete.

A total of 66 sets of pullout specimens were prepared to investigate the bonding properties of basalt fiber-reinforced polymer reinforcement (hereinafter referred to as BFRP) with seawater sand concrete (hereinafter referred to as SSC). The volume dosages of mono-doped glass fibers and mono-doped polypropylene fibers were 0.1%, 0.2%, and 0.3%; the total volume dosage was set to be constant at 0.3%; and the doping ratios of the hybrid fibers were 1:2, 1:1, and 2:1. The effect on the bonding performance of BFRP reinforcement with SSC was studied on the condition of the diameter D of the BFRP reinforcement being 12 mm; the bond length of SSC being 3D, 5D, and 7D; and the surface characteristics of the reinforcement being sandblasted and threaded. The research showed that due to internal cracks in the matrix, salt crystals in the pores, chloride salts with high brittleness and expansion, as well as sulfate corrosion products such as "Frederick salts" in SSC, the concrete became brittle, resulting in more brittle splitting failures during the pullout test. Doped fibers can increase the ductility effect of concrete, but the bonding effect between the threaded fiber reinforcement and the SSC was not as good as that of the sandblasting group. When the bond length was 5D, the bonding effect between the BFRP reinforcement and SSC was the best, and the bonding performance of the experimental group with doped fibers was better than that of the threaded group. Finally, by combining the ascending segment of the Malvar model with the descending segment of the improved BPE model, a constitutive relationship model suitable for the bond-slip curve between BFRP reinforcement and SSC was fitted, which laid a theoretical foundation for future research on SSC.

Application of Composite Bars in Wooden, Full-Scale, Innovative Engineering Products-Experimental and Numerical Study.

The commercialization of modular timber products as cost-effective and lightweight components has resulted in innovative engineering products, e.g., glued laminated timber, laminated veneer lumber, I-beams, cross-laminated timber and solid timber joined with wedge joints. With the passage of time, timber structures can deteriorate, or new structural elements are required to increase the stiffness or load-bearing capacity in newly built structures, e.g., lintels over large-scale glazing or garages, or to reduce cross-sectional dimensions or save costly timber material while still achieving low weight. It is in such cases that repair or correct reinforcement is required. In this experimental and numerical study, the static performance of flexural timber beams reinforced with prestressed basalt BFRP, glass GFRP and hybrid glass-basalt fiber bars is shown. The experimental tests resulted in an increase in the load-carrying capacity of BFRP (44%), GFRP (33%) and hybrid bars (43%) and an increase in the stiffness of BFRP (28%), GFRP (24%) and hybrid bars (25%). In addition to this, glued laminated timber beams reinforced with prestressed basalt rods subjected to biological degradation, 7 years of weathering and prolonged exposure to various environmental conditions were examined, and an increase in the load-bearing capacity of 27% and an increase in stiffness of 28% were obtained. In addition, full-size laminated timber beams reinforced with prestressed basalt bars were investigated in the field as an exploratory test under fire conditions at elevated temperatures, and the effect of the physical-mechanical properties during the fire was examined via an analysis of these properties after the fire. In addition, a satisfactory correlation of the numerical simulations with the experimental studies was obtained. The differences were between 1.1% and 5.5%. The concordance was due to the fact that, in this study, the Young, Poisson and shear moduli were determined for all quality classes of sawn timber. Only a significant difference resulted in the numerical analysis for the beams exposed to fire under fire conditions. The experimental, theoretical and numerical analyses in this research were exploratory and will be expanded as directions for future research.

Nutritional, Textural, and Sensory Attributes of Protein Bars Formulated with Mycoproteins.

Research accumulated over the past decades has shown that mycoprotein could serve as a healthy and safe alternative protein source, offering a viable substitute for animal- and plant-derived proteins. This study evaluated the impact of substituting whey protein with fungal-derived mycoprotein at different levels (10%, 20%, and 30%) on the quality of high-protein nutrition bars (HPNBs). It focused on nutritional content, textural changes over storage, and sensory properties. Initially, all bars displayed similar hardness, but storage time significantly affected textural properties. In the early storage period (0-5 days), hardness increased at a modest rate of 0.206 N/day to 0.403 N/day. This rate dramatically escalated from 1.13 N/day to 1.36 N/day after 5 days, indicating a substantial textural deterioration over time. Bars with lower mycoprotein levels (10%) exhibited slower hardening rates compared with those with higher substitution levels (20% and 30%), pointing to a correlation between mycoprotein content and increased bar hardness during storage. Protein digestibility was assessed through in vitro gastric and intestinal phases. Bars with no or low-to-medium levels of mycoprotein substitution (PB00, PB10, and PB20) showed significantly higher digestibility (40.3~43.8%) compared with those with the highest mycoprotein content (PB30, 32.9%). However, digestibility rates for all mycoprotein-enriched bars were lower than those observed for whey-protein-only bars (PB00, 84.5%), especially by the end of the intestinal digestion phase. The introduction of mycoprotein enriched the bars' dietary fiber content and improved their odor, attributing a fresh mushroom-like smell. These findings suggest that modest levels of mycoprotein can enhance nutritional value and maintain sensory quality, although higher substitution levels adversely affect texture and protein digestibility. This study underscores the potential of mycoprotein as a functional ingredient in HPNBs, balancing nutritional enhancement with sensory acceptability, while also highlighting the challenges of textural deterioration and reduced protein digestibility at higher substitution levels.

Patient outcomes and complications following various maxillomandibular fixation techniques: A systematic review and meta-analysis.

PURPOSE: Currently, there are several methods of achieving maxillomandibular fixation (MMF), each with its unique operative considerations and subsequent patient outcomes and complications. In this study, we reviewed the literature to evaluate and compare all MMF methods. METHODS: A systematic review of all MMF types was conducted and post-operative outcome data were analyzed and compared among the different types. Conventional Erich arch bars were compared to hybrid arch bars, MMF screws, and eyelet interdental wiring. A random-effects meta-analysis was used to determine the mean differences, and 95% confidence intervals (CIs) with a statistical significance of P < 0.05. RESULTS: Among the 4234 articles identified, 24 were included, and 17 were meta-analyzed. Time to achieve MMF (-43.38 min; 95% CI, -58.20 to -28.56; P < 0.001), total operative time (-30.33 min; 95% CI, -61.05 to 0.39; P = 0.05), incidence of wire puncture injuries and glove perforations (0.11; 95% CI, 0.04 to 0.30; P < 0.001), and incidence of poor oral hygiene (0.08; 95% CI, 0.02 to 0.28; P < 0.001) were lower for alternative MMF interventions compared to those of the conventional Erich arch bars. CONCLUSIONS: Alternative MMF methods required shorter operative time to achieve MMF and demonstrated other increased efficiencies of practice such as shorter total operative time and decreased glove perforations, when compared to conventional Erich arch bars. If a patient is a candidate for MMF, the presented alternative MMF techniques should be considered depending on the clinical context and availability of institutional resources.

Assessing the cadmium content of cacao crops in Arauca, Colombia.

The district of Arauca is the second-largest producer of cacao in Colombia. However, despite its quality, it faces issues for export due to levels of cadmium (Cd) higher than the regulatory thresholds. A central question is how it may impact agricultural performance in the presence of Cd in cacao and chocolates. This study quantified Cd in cacao plantations from Arauca. Thus, 180 farms were assessed in the municipalities of Arauquita, Fortul, Saravena, and Tame. Five sample types (soil, irrigation channel sediment, soil litter, cacao seeds, and chocolates) were assessed for Cd. As a technological innovation, the new MXRF technology was used for Cd in chocolates. The sequence of Cd content was soil litter > chocolate > soils > cacao seeds > irrigation-channel sediment. A gradient north-south of Cd content in soil was observed, where highest content was found in farms near the Arauca River, and lower farther away. In irrigation channel sediment, Cd levels averaged 0.07 mg kg-1. The Cd content in cacao seeds was 0.78 mg kg-1 on average. Cd content in chocolates was above the threshold (1.10 mg kg-1 on average, including several cacao mass percentages). These artisanal chocolate bars produced by single farms were near the limit of Cd set by the European Union (up to 0.8 mg kg-1). Therefore, mixing beans from different farms could reduce their Cd content. The present study underscores the complexity of Cd distribution, emphasizing the importance of integrating soil, crop, and landscape features in managing and mitigating Cd levels in cacao.

Structural performance of FRP composite bars reinforced rubberized concrete compressive members: Tests and numerical modeling.

Waste tyre rubber has become an environmental and health concern that needs to be sustainably managed to avoid fire hazards and save natural resources. This research work aims to study the structural behavior of glass fiber reinforced polymer (glass-FRP) reinforced rubberized concrete (GRC) compressive elements under monotonic axial compression loads. Nine GRC circular compressive elements with different axial and crosswise reinforcement ratios were fabricated. All the elements were 300 mm in diameter and 1200 mm in height. A 3D nonlinear finite element equation (FEM) was suggested for the GRC compressive elements using a commercial package ABAQUS. A parametric study has been done to examine the effect of various parameters of GRC elements. The test outcomes revealed that the ductility of GRC elements ameliorated with the lessening in the spaces of glass-FRP ties. The addition of rubberized concrete improved the ductility of GRC elements. The damage to GRC elements occurred due to the vertical cracking along the height of the elements. The estimates of FEM were in close agreement with the test outcomes. The suggested empirical equation depending on the 600 test elements, which considered the lateral confinement effect of FRP ties, presented higher accuracy than previous equations.

Development and Rapid Sensory Descriptive Characterization of Cereal Bars Made with Brazilian Licuri Nut (Syagrus coronata).

Licuri (Syagrus coronata) is an oilseed fruit common in the Brazilian caatinga and cerrado biomes. This fruit has high socioeconomic importance in the regions where it grows, being incorporated into exported animal feed and also into gastronomic preparations. Cereal bars are ready-to-eat highly consumed products with increased demand, commonly made with cereals and oilseeds such as licuri. In this sense, the incorporation of licuri in cereal bars may increase its socioeconomic value and expand its potential use. Thus, the objective of the study was to analyze acceptance and describe the sensory characteristics of cereal bars incorporated with licuri nuts. This study was conducted in four stages: (1) development of samples; (2) chemical composition analysis; (3) sensory analysis; and (4) statistical analysis. Cereal bars with licuri presented proportionally lower carbohydrate and protein content as the incorporation of licuri nut increased. However, the dietary fiber content increased. Further, 122 untrained panelists participated in the analysis. The results showed that samples with all proportions of incorporation of licuri nuts were acceptable. Furthermore, the sensory descriptors related to the presence of licuri were positively associated with product acceptance. In this way, this study demonstrates yet another possibility for use of the fruit, increasing its socioeconomic potential.

Development and Characterization of High-Energy Protein Bars with Enhanced Antioxidant, Chemical, Nutritional, Physical, and Sensory Properties.

Protein-rich energy bars are known as an excellent nutritional supplement for athletes that help to build and repair connective tissues. The study is, therefore, aimed at developing high-protein bars using lupine seeds, wheat germ, and selected dried fruits including raisins, dates, apricots, and cranberries. Different formulations (F1, F2, F3, and F4) were performed at different ratios of ingredients to produce high-protein bars and compared them with a control bar made of whey-protein concentrate and oat flakes. For this purpose, a proximate analysis, total phenol content, total flavonoid content, DPPH radical scavenging activity, water content, nutritional, and sensory analysis was performed to evaluate the results. The proximate analysis of the produced protein bars showed a significantly higher protein content (22 ± 2) and total phenolic activity (57 ± 33) in formulation group 4 as compared to the other groups. Furthermore, the least water activity content was found in formulation group 1 (1 ± 0.0) when compared with the control group (1 ± 0.0). The results from the sensory evaluation revealed that T3 had the highest average scores in overall consumer acceptability. Our study found that total phenolic, flavonoid, and fiber content were significantly higher in the prepared protein bars indicating prospective health benefits when compared to the control group. Overall, the study demonstrates that high-protein bars using functional ingredients like dried fruit can provide enriched nutritionally valuable food options for consumers.

Validation and refinement of the "Airman Comprehensive Assessment": Evaluating competency proficiencies of enlisted members.

Beyond proficiency on occupationally specific tasks, the U.S. Air Force expects members to develop proficiency on institutionally valued "soft skill" competencies (e.g., Teamwork, Communication, and Initiative) throughout their careers. As such, all E1-E6 members are annually evaluated using Behaviorally Anchored Rating Scales (BARS) designed to measure such competencies. Despite mandated use, these Airman Comprehensive Assessment (ACA) scales previously have not been empirically evaluated. To address this gap, we surveyed Air Force supervisors, using a criterion-related sampling methodology to validate the behavioral anchors for each scale. Supervisors identified two subordinates of the same rank/career field who they viewed as having (a) high potential for future success in an Air Force career or, alternately, (b) lower potential for future career success and rated each subordinate on the individual behaviors that comprise the 12 scales. ACA items were intermixed with scale items previously identified as distinguishing top performers in civilian organizations. Results demonstrate scale reliability and generally validate the ACA competency scales as stronger differentiators of supervisor-rated career potential than competency scales developed for civilian organizations. We provide recommendations for re-calibration of scale anchors based on the relative percentage of high vs. low potential members that demonstrate each behavior, and suggest changes to improve correspondence between measured competency proficiency and supervisor-rated career potential.

Usefulness of one-arm motorized gait device for chronic hemiplegic stroke survivors.

BACKGROUND: After stroke, gait training is a key component of rehabilitation, and most individuals use a variety of walking aids depending on their physical condition and environment. OBJECTIVE: This study aimed to investigate the potential effect of a one-arm motorized gait device for gait assist of chronic hemiplegic stroke survivors through comparison with traditional gait devices (parallel bar and hemi-walker). METHODS: This study was conducted on 14 chronic hemiplegic stroke survivors. The participants were asked to walk under three conditions using different gait devices, and their gait parameters during walking were collected and analyzed. The first condition involved walking on parallel bars; second condition, walking using hemi-walkers; and third condition, walking using one-arm motorized gait devices. With the use of a gait analysis system, the spatio-temporal gait parameters in each condition were collected, such as gait velocity, cadence, step length, stride length, single support time, and double support time. RESULTS: In the results by repeated-measures ANOVA or the Friedman test, a significant difference was found in the gait parameters among all three conditions (p< 0.05). The post-hoc test showed a significant change in the spatio-temporal gait parameters (especially, velocity, cadence and affected side single and double support time) when one-arm motorized gait device were used compared with parallel bars and hemi-walkers (p< 0.05). CONCLUSION: The results of this study suggest that one-arm motorized gait devices developed for hemiplegic stroke survivors may be more effective potentially than parallel bars and hemi-walkers in gait assistance of chronic hemiplegic stroke survivors.

Multisensory Spatial Analysis and NDT Active Magnetic Method for Quick Area Testing of Reinforced Concrete Structures.

This paper aims to present multisensory spatial analysis (MSA). The method was designed for the quick, simultaneous identification of concrete cover thickness h, rebar diameter, and alloys of reinforcement in large areas of reinforced concrete (RC) structures, which is a complex and unsolved issue. The main idea is to divide one complex problem into three simple-to-solve and based on separate premises tasks. In the transducers designed with the MSA, sensors are arranged spatially. This arrangement identifies each RC parameter separately based on the different waveforms/attributes. The method consists of three steps. All steps are described in the paper and supported by simulations and statistical analysis of the measurement. The tests were carried out using an Anisotropic Magneto-resistance (AMR) sensor. The AMR sensors can measure strong DC magnetic fields and can be combined in spatial transducers because of their small size. The selection of the sensor was extensively justified in the introduction section. The spatial transducer and the identification's simplicity can allow for high accuracy in the real-time area testing of all three parameters. The risk of misclassification of discrete parameters was strongly reduced, and the h parameter can be identified with millimeter accuracy.

Evaluation of the P-Δ (P-Delta) effect in columns and frames using the two-cycle method based on the solution of the beam-column differential equation.

P-Delta is a nonlinear phenomenon that results from the consideration of axial loads acting on the deformed configuration of a member of the structure, usually a beam-column. This effect is especially significant in slender members, which can undergo large transversal displacements which tend to increase the bending moment caused by an axial load P acting upon them. The P-delta effect can be computed through a geometrically nonlinear analysis, usually employing the Finite Element Method, which subdivides each bar of the frame in finite segments known as elements. Since discretization (subdivision) and the use of iterative schemes (like Newton-Raphson) are sometimes undesirable, especially for students, avoiding it can be didactically interesting. This work proposes the use of a new approach to perform a simplified nonlinear analysis using the two-cycle method and a tangent stiffness matrix obtained directly from the homogeneous solution of the problem's (beam-column) differential equation. The proposed approach is compared to the results obtained by the traditional two-cycle method which uses geometric and elastic stiffness matrices based on cubic (Hermitian) polynomials and a P-Delta approximation using the pseudo (fictitious) lateral load method.

Experimental and Theoretical Studies of the Thermal Contact Conductance for Bundles of Round Steel Bars.

The paper presents investigations devoted to the analysis of the thermal contact conduction in a bundle of round steel bars. The phenomenon can be expressed quantitatively with the use of thermal contact conductance (hct). The starting points for the presented analysis were the results of the experimental measurements of the effective thermal conductivity. The measurements were performed for samples of a medium in the form of flat packed beds of bars with three different arrangements: staggered, in-line, and crossed and four bar diameters: 10, 20, 30, and 40 mm. Next, a mathematical model was developed, thanks to which the values of the hct coefficient were calculated for the analyzed cases. This approach consists in analyzing thermal resistances in the medium model, which is defined with an elementary cell. It was established that the value of the hct coefficient in the temperature range of 50-600 °C changes within the range of 50-175 W/(m2·K), and it decreases with an increase in the bar diameter. The final effect of the present study was to develop generalized approximation equations describing changes in thermal contact conductance in the heated bar bundle simultaneously in the temperature and bar diameter function.

Effect of the Rolling Process on the Properties of the Mg/Al Bimetallic Bars Obtained by the Explosive Welding Method.

This study aims to analyze the influence of the rolling process on the microstructure and corrosion properties of the Mg/Al bimetallic bars obtained by the explosive welding method. The bars investigated were rolled using two different types of rolling: classical rolling (Variant I) and modified rolling (Variant II). Two different temperatures (300 °C and 400 °C) for each of the variables were applied as well. In this study, rods with an aluminum plating layer constituting 16.8% of the cross-sectional area and an average thickness of about 0.93 mm were investigated. Based on the revealed results, it was found that after the rolling process, the material shows clearly lower values of both icor and current in the passive range. In the joint zone of Mg/Al rods rolled at 400 °C, Al3Mg2 and Mg17Al12 intermetallic phases are distinguished, localized next to the Mg core, and characterized by columnar, coarser grains. In the transition zone closer to the Al layer, only the Al3Mg2 phase is revealed, characterized by a refined, small grain size.