Shear Force Research Articles

Effects of shear on the lateral torsional buckling of singly-symmetric I-beams

This paper presents an investigation on the negative effects of shear on the lateral torsional buckling (LTB) of singly-symmetric I-shaped beams due to web distortion associated with shear. Results from a parametric FEA study including eigenvalue buckling analyses and large-displacement analyses were utilized considering both stiffened and unstiffened webs to consider the impact of shear on the LTB resistance. Moment gradients caused by constant shear and a shear gradient were considered. The FEA solutions demonstrate that shear can significantly reduce the lateral-torsional buckling resistance. The FEA results were used to develop design equations that account for the reduction in the LTB capacity from shear. The solutions were compared with conventional methods proposed by Winter to account for the effects of web distortion on girders with slender webs. Results from the study show that (i) the average flange area should be used to account for the effects of shear of singly-symmetric beams; (ii) post-buckling strength has limited impact on the shear effects with regards to the LTB resistance; and, (iii) compared to Winter's approach, the proposed method can capture the variation of the moment reduction factor with the shear force in the unbraced length, and is able to predict moment resistances with reasonable accuracy compared to refined FEA solutions using both eigenvalue analysis and large-displacement analysis. Design examples are provided to demonstrate the calculation procedure.

Analysis of the Effects of Microwave Combined Induction Heating on Steamed Pork with Rice Powder.

This study investigates the application of microwave combined induction heating (MCIH) to steam ready-to-eat pork with rice powder, emphasizing the advantages of rapid and uniform heating. The experimental setup included a mixture of 180 g pork strips, 30 g rice powder, and 10 g water in a CPET tray using MCIH with 1080 W microwave (MW) and 130 °C induction heating (IH) for 150 s. The results showed a quick temperature increase rate of 0.56 °C/s that achieved pasteurization against a variety of pathogenic bacteria, such as Listeria monocytogenes, but not Clostridium botulinum, by lethality calculation. Compared to typical electric cooker steaming, MCIH significantly shortened cooking time (8.6 times faster). To address rice starch gelatinization, two-stage heating techniques to steam pork with rice powder were MCIH: 150 s, and then IH: 60 s (MW1), and MCIH: 180 s, and then IH: 30 s (MW2), with no significant differences seen in color or the nine-point taste scale between treatment groups. MCIH groups had smaller shear forces than control. After MCIH cooking, no microbial counts were detected in the MW1 and MW2 groups initially, and the pork with rice powder had a shelf life of 14 days at 4 °C based on aerobic plate count assay.

Exploration of Microencapsulation of Arginine in Carnauba Wax (Copernicia prunifera) and Its Dietary Effect on the Quality of Beef.

The objective of this exploratory study was to assess if microencapsulated arginine influences the physicochemical quality of beef. The study included three genetic groups: Angus, Hereford, and Angus × Hereford crossbreed. Two encapsulation systems were used with carnauba wax, at ratios of 3:1 and 2:1, carnauba wax:core (arginine), respectively. A control treatment was also included with no arginine addition. Encapsulated arginine with a 3:1 ratio increased redness by 19.66 at 28 d aged beef compared to the control and 2:1 ratio with values of 18.55 and 16.77, respectively (p = 0.01). Encapsulated arginine at a 3:1 ratio showed the lowest meat shear force values with 24.32 N at 28 d of ageing (p < 0.001). The Angus breed also had a low value of 24.02 N (p < 0.001). Finally, the highest values of intramuscular fat were observed with the inclusion of arginine in a 3:1 ratio. The fat value reached 2.12% with a 3:1 ratio (p = 0.002), while in the Angus breed it was 1.59%. The addition of carnauba wax-encapsulated arginine can improve meat quality. It enhances red color, tenderness, and marbling in bovine meat.

Rosa roxburghii tratt residue as an alternative feed for improving growth, blood metabolites, rumen fermentation, and slaughter performance in Hu sheep.

The utilization of agro-industrial by-products, such as fruit residues, presents a promising strategy for providing alternative feed to ruminants amidst rising prices and limited availability of traditional roughage. In this study, we investigated the effects of Rosa roxburghii tratt residue, a local fruit residue in Guizhou province of China, on the growth, blood metabolites, rumen fermentation, and slaughter performance of Hu sheep. Ninety-six sheep were randomly divided into four groups, namely control, treatment 1, treatment 2, and treatment 3, and fed diets containing 0, 10, 20, and 30% Rosa roxburghii Tratt residue, respectively. Feeding varying levels of Rosa roxburghii Tratt residue showed no significant differences in dry matter intake, average daily gain, or the ratio of dry matter intake to average daily gain. However, sheep in the group fed with 30% Rosa roxburghii Tratt residue showed the highest gross profit. Plasma albumin content was lower in groups fed with Rosa roxburghii Tratt residue-containing diets compared to the control group (p < 0.05). Additionally, diet treatment 3 decreased plasma creatinine levels compared to control and treatment 1 (p < 0.05). Sheep in treatment 2 and treatment 3 exhibited higher plasma high-density lipoprotein level than control and treatment 1 (p < 0.05), as well as increased total cholesterol levels compared to control (p < 0.05). There were no significant differences in other plasma metabolites. Rumen pH, N-NH3, volatile fatty acids, and methane levels did not differ significantly among the four groups. However, feeding diets treatment 2 and treatment 3 resulted in decreased water holding capacity and increased shear force compared to control and treatment 1 (p < 0.05). Furthermore, pH, red chromaticity (a*), yellowness index (b*), and luminance (L*) were unaffected among the four groups of sheep. In conclusion, the inclusion of up to 30% Rosa roxburghii Tratt residue had no adverse effects on growth performance, allowing for feed cost savings without impacting rumen fermentation parameters. Rosa roxburghii tratt residue also showed benefits in improving plasma protein efficiency and enhancing lipid metabolism, albeit with limited effects on meat quality. Considering its affordability, Rosa roxburghii Tratt residue presents a practical choice for low-cost diets, ensuring economic returns.

Meta-analysis to predict the effects of probiotics on meat quality of broiler.

The demand for chicken meat has surged globally due to its status as a primary protein source in human diets. However, ensuring high-quality meat products has become an increasingly important subject to consumers. In this study, 21 articles from PubMed and Web of Science databases published between 2005 and 2023 were examined to assess the influence of probiotic supplementation on broiler meat quality. The meta-analysis revealed significant findings across various meat quality parameters. Specifically, probiotics were found to significantly affect meat colour parameters, including redness, yellowness, and lightness, in both breast and thigh meat samples. Moreover, significant differences were observed in parameters such as water-holding capacity (p < 0.001), cook loss (p = 0.047), and shear force (p = 0.025) between control and probiotic groups. However, it's essential to note the considerable heterogeneity among the studies, emphasising the need for a cautious interpretation of the results. Despite this variability, the study underscores the potential of probiotics to positively influence broiler meat quality, highlighting avenues for further research and standardisation in poultry production practices. These findings also contribute to a better understanding of probiotics' role in improving meat quality and meeting consumer preferences for nutritious and high-quality poultry products.

Lateral soil-pile interaction of large-diameter rigid monopiles supporting OWTs in clay: Insights and an enhanced theoretical model

The application of large-diameter rigid monopiles is a growing trend in offshore wind turbine projects. Among the various models used to simulate the lateral response of these monopiles, the {‘p−y’+‘MR−θR’} model has emerged as an effective choice. However, this model has certain limitations, such as its inability to capture the rotation flow mechanism above the pile rotation center and its neglect of vertical friction at soil-pile interface. To address these limitations and enhance our understanding of soil-pile interaction mechanisms for large-diameter rigid monopiles, we develop a modified {‘p−y’+‘MR−θR’+‘ms−θR’} model that accurately captures all three components of soil-pile interaction. This improved model expands the upper range dominated by the concentrated rotation spring to include depths where shear force on the pile section approaches zero, and incorporates distributed moment resistance from vertical shaft friction into consideration. We present several validation cases that demonstrate its superiority over previous methods such as API method and {‘p−y’+‘MR−θR’} method. Additionally, through parametric analysis based on our proposed method, we investigate how pile diameter and eccentricity influence internal mechanisms of soil-pile interaction. Our findings reveal that vertical friction at the soil-pile interface plays a significant role in large-diameter cases while rotation flow mechanism dominates in situations with large-eccentricity. Furthermore, we provide a concise empirical expression for estimating lateral bearing capacity of large-diameter rigid monopiles at serviceability limit state which can be conveniently applied during preliminary design stages in practical engineering.

Stress modulation strategies in Kluyveromyces marxianus: Unravelling the effects of shear force and aeration for enhanced specific ergosterol production

AbstractErgosterol, as a precursor for synthesising useful molecules like vitamin D2, possesses significant physiological functions in both fungal and human systems. In fungi, ergosterol plays a crucial role in stress responses. In contrast to Saccharomyces cerevisiae yeast, the changes in specific ergosterol content of Kluyveromyces marxianus under various stress conditions are less known. This study investigated how ergosterol content changes in response to different stress factors. Carbon to nitrogen (C/N) ratio was examined using experimental design. The effects of aeration and shear force beside constant overall volumetric mass transfer coefficient (KLa) were examined. Cell growth and specific ergosterol content were investigated using ethanol stress during a two-stage fermentation. Based on the results, contradictory settings regarding C/N ratio and shear force were found to be favourable for cell growth and specific ergosterol content. However, increased aeration consistently elevated specific ergosterol content and favoured cell growth as well (2.5-fold and 1.5-fold, respectively). In K. marxianus fermentations, higher ergosterol yield can be achieved through a two-stage fermentation (138.9 mg L−1 compared to 52.9 mg L−1), where the first stage provides favourable conditions for cell growth, and the second stage involves stress (beneficial for ergosterol production) conditions. Conclusions drawn from the two-stage fermentation results suggest that early transitioning of cell growth to the second phase will not result higher adaption and specific ergosterol content compared to the transition at the end of exponential growth phase.

A novel stick-slip piezoelectric actuator is developed based on a parallelogram flexible drive mechanism to minimize shear force

A piezoelectric actuator utilizing a parallelogram flexible mechanism is proposed. This actuator harnesses the parasitic motion generated by a parallelogram driven by a piezoelectric element. It differs from existing actuation mechanisms based on a similar principle in that the piezoelectric stack is positioned on the outside of the parallelogram flexible mechanism, thus protecting it from shear forces. Finite element simulations and experiments confirm this. The analysis was conducted using theoretical analysis and finite element simulation. The optimal drive angle for the parallelogram flexible mechanism was determined through finite element simulation. Additionally, a prototype actuator and an experimental measurement system were developed to assess the operational performance of the proposed piezoelectric actuator. When the driving frequency is 475 Hz and the locking force is 5 N, the motion of the actuator achieves a maximum speed of 5.65 mm s−1 and a maximum horizontal load of up to 113 g; when the input frequency is 1 Hz and the input minimum starting voltage is 8 V, the minimum displacement resolution is 30 nm. A comparative analysis of experimental results, theoretical calculations, and finite element simulation results demonstrates the feasibility of the structural design.

Different rheological behaviors of reinforced poly(methylvinylsiloxane) by mesoporous and spherical silica microparticles

To elucidate the mechanism underlying the high performance of mesoporous silica aerogel microparticle (SAG) in reinforcing polymers, the hydrodynamic effect and reinforcement effect of SAG microparticle in Poly-methylvinylsiloxane (PMVS) were investigated. For comparison, regular spherical silica particles (SS) with a comparable particle size and smooth surface were also incorporated into the study as a contrasting filler. It was found that SAG tended to form aggregates with high aspect ratio (shape factor f values between 16-20) and highly branched backbone structures (x = 1.95). However, these aggregates are more loosely packed (df = 1.7) and easily break into smaller flocs under the influence of shear forces. The load-bearing mechanism of the spatial network formed by these aggregates as nodes was akin to physical gels controlled by bond-bending forces (BBFs), with a scaling exponent of G*r with φe-φc of ν = 3.84, close to the theoretical value of the BBFs model. In contrast, the SS particles formed more compact aggregates (f value approximately 1.6) in PMVS, with load-bearing characteristics of the spatial network formed by them closer to chemical gels controlled by central forces (CFs). The scaling exponent of G*r with φe-φc for SS/PMVS was found to be ν = 2.15, close to the theoretical value of the CFs model.

Harnessing oriented arrangement of collagen fibers by 3D printing for enhancing mechanical and osteogenic properties of mineralized collagen scaffolds

As the structural basis of connective and load-bearing tissues, collagen fibers with orientation play an important role in the mechanical properties and physiological and biochemical functions of the tissues, but viable methods for preparing scaffolds with highly oriented collagenous structure still need to be further studied. In this study, pure collagen was used as printing ink to 3D printing. Harnessing oriented collagen fiber structure by 3D printing for promoting mechanical and osteogenic properties of scaffolds. The scaffolds with different printed angles and thicknesses were prepared to fit the bone defect site and realize personalized customization. The orientation assembly of collagen fibers was promoted by shear force action of 3D printing, the regular arrangement of collagen fibers and stabilization of fiber structure were promoted by pH adjustment and glutaraldehyde cross-linking, and the collagen fibers were mineralized by cyclic mineralization method. The microscopic morphology of fiber arrangement in the scaffolds were investigated by scanning electron microscopy. Results demonstrated that collagen fibers were changed from non-oriented to oriented after 3D printing. And the tensile modulus of the scaffolds with oriented collagen fibers was nine times higher than that of the scaffolds with non-oriented fibers. Moreover, the effects of oriented collagen fibers on the proliferation, differentiation and mineralization of MC3T3-E1 cells were studied by CCK-8 assay, live/dead cell staining, alkaline phosphatase activity test, and Alizarin red staining. The results indicated that cell proliferation, differentiation and mineralization were significantly promoted by oriented collagen fibers, and the cells proliferated directionally in the direction of the fibers. Taken together, mineralized collagen fiber scaffolds with oriented collagen fibers have great potential in bone tissue engineering applications.

Effect of the addition of black garlic on the quality parameters of jerked beef meat with pork.

The objective of this work was to evaluate the effects of the replacement of nitrite by natural antioxidants from black garlic (BG) on the quality parameters of jerked beef meat with pork for 60 days. Four formulations were prepared: control, 0.02% of sodium nitrite in brine curing, w/v (CON); 1.5% BG in brine curing, w/v (ASU); 1.5% BG in dry curing, w/w (ASS); and 1.5% of BG in the brine curing, w/v and 1.5% of BG in dry curing, w/w (ASUS). Nutritional composition, pH, water activity, shear force, fatty acid profile, color, and oxidative stability of the formulations were analyzed. The addition of BG did not affect the nutritional composition, pH, water activity, shear force, and fatty acid profile. On the other hand, it resulted in lower weight loss after centrifugation and lower values of L* and a*. TBARS values from the 30th day of storage were lower in the ASUS formulation, while carbonyl compounds at all times were lower than in the CON formulation. Results suggest that BG was an efficient alternative to nitrite in controlling protein oxidation during storage. Thus, the use of pork for the manufacture of jerked beef can be an alternative, and black garlic can be applied as a natural additive to the replacement of nitrite. In addition, black garlic was efficient in improving the oxidative stability of the jerked beef meat with pork.

Effect of distillers yeast in feed on texture, fatty acid profile and antioxidant properties of breast muscle of broiler chickens

This research aimed to assess the impact of replacing a partially of post-extraction soybean meal in the diet with varying amounts of distillers yeast (3, 6 and 9%) on the composition and quality in the pectoral muscles of broiler chickens. Findings revealed that cockerels fed with 3% yeast exhibited elevated oleic acid levels and reduced n-6 fatty acids compared to those fed with 6% and 9% yeast. Furthermore, chickens consuming 3% yeast displayed higher antioxidant capacity (ABTS) and decreased levels of linoleic acid and its ratio to α-linolenic acid compared to the 9% yeast group. Moreover, muscles from cockerels on the 3% yeast diet and the control group demonstratedhigher shear force, lower n-6/n-3 ratio and lipid peroxidation rate (TBARS) than those on the 9% yeast regimen. Conversely, cockerels on the 9% yeast diet exhibited reduced gumminess and ferric reducing antioxidant power (FRAP) compared to the control group. The study highlights yeast’s role in altering broiler chicken meat’s fatty acid profile, texture, and antioxidant properties.

On the Shear Force Redistribution in Composite Steel and Concrete Beams with Web Openings

As far as research into the field of composite steel and concrete beams with web openings has shown, the initiation of a complex stress state due to the introduction of web openings is, unfortunately, inevitable. As a logical consequence, estimation of the resistance becomes complex as well. Aiming to provide a more convenient approach, especially for evaluation of the bending resistance to the Vierendeel effect with the presence of high shear forces, a marked simplification with respect to quantification of the shear force redistribution between T-sections is presented. This novel approach stands on strong fundamentals of experimental evidence and parametric finite element (FE) investigation. Concretely, within the experimental part of this investigation, the load response of four composite beam samples was recorded and profoundly analyzed. Subsequently, a detailed FE analysis in the software ANSYS 2024 R1 (ANSYS Inc., Canonsburg, PA, USA), exploiting its parametric design language (APDL), was conducted. Finally, concise data compilation and their comprehensible interpretation were enabled by employing the software MATLAB 2024a (The MathWorks, Inc., Natick, MA, USA). In view of this treatment, a cornerstone for successive assessment of the obtained data was laid. Attempting to identify the key factors influencing the shear force proportion between the tees, integration of the shear stresses along the vertical sections with regular spacing along the FE beam models was conducted. By virtue of this concept, not only the magnitudes of the shear forces for the tees were obtained but also the leading importance of the opening depth was demonstrated. Furthermore, a complete picture of the shear force behavior along the composite perforated beams was derived. On this basis, a novel method representing a simpler and more accurate form of estimation of the shear force proportion for T-sections was proposed.

Numerical modeling of the heat and mass transfer of rarefied gas flows in a double-sided oscillatory lid-driven cavity

In micro/nano research and engineering applications, internal flows of rarefied gas in confined geometries with moving parts are of great interest. The rarefied gaseous flows in an oscillating lid-driven cavity are investigated numerically in this work, taking into account both the parallel and antiparallel motion of the driving walls. The discrete unified gas kinetic scheme (DUGKS) is applied to the evolution of the flow and temperature fields. The Shakhov collision model is incorporated into DUGKS to account for flows of non-unit Prandtl numbers. The validity of the Shakhov-DUGKS is confirmed in both single-sided oscillating and steady lid-driven cavity flows. The effects of gas compressibility, rarefaction, and lid oscillation frequency on the mass and heat transport are then thoroughly examined. The corresponding parameter spaces of the Mach, Knudsen and Stokes numbers are 0.16 ≤ Ma ≤ 1.2, 0.075 ≤ Kn ≤ 10 and 0.5 ≤ St ≤ 5, respectively. The shear force and Nusselt number Nu on the cavity walls, as well as the velocity, temperature, and heat flux lines in the cavity, are measured and analyzed. The results suggest that the anti-Fourier heat transfer phenomenon might also occur in the rarefied double-sided oscillating cavity flow. Nu is prone to non-simple harmonic oscillation in its evolution. Furthermore, in the parallel motion as opposed to the anti-parallel motion, the left wall experiences a greater intensity of heat transmission. Compressibility, expansion cooling, and viscous heating compete to provide the complicated flow and heat transfer characteristics found in cavities.

Shear force effect of the dry process on cathode contact coverage in all-solid-state batteries

The state-of-the-art all-solid-state batteries have emerged as an alternative to the traditional flammable lithium-ion batteries, offering higher energy density and safety. Nevertheless, insufficient intimate contact at electrode-electrolyte surface limits their stability and electrochemical performance, hindering the commercialization of all-solid-state batteries. Herein, we conduct a systematic investigation into the effects of shear force in the dry electrode process by comparing binder-free hand-mixed pellets, wet-processed electrodes, and dry-processed electrodes. Through digitally processed images, we quantify a critical factor, ‘coverage’, the percentage of electrolyte-covered surface area of the active materials. The coverage of dry electrodes was significantly higher (67.2%) than those of pellets (30.6%) and wet electrodes (33.3%), enabling superior rate capability and cyclability. A physics-based electrochemical model highlights the effects of solid diffusion by elucidating the impact of coverage on active material utilization under various current densities. These results underscore the pivotal role of the electrode fabrication process, with the focus on the critical factor of coverage.

Optimizing growth and antioxidant function in heat-stressed broilers with vitamin C and betaine supplementation.

This study investigates the potential of vitamin C (VC) and/or betaine (Bet) to enhance growth performance, regulate serum metabolism, and bolster antioxidant function aiming to mitigate the impact of heat stress (HS) on broilers. Two hundred Ross 308 broilers at 28 days of age were randomly assigned to five groups. The control group, housed at 24 ± 1℃, was fed a basal diet. High-temperature treatment groups, housed at 32 ± 1℃, received a basal diet with 0 (HS group), 250mg/kg VC (HSVC group), 1000mg/kg Bet (HSBe group), and 250mg/kg VC + 1000mg/kg Bet (HSVCBe group). On day 42, assessments were made on growth performance, muscle quality, serum biochemistry, and antioxidant function. Results revealed that HS significantly lowered (P < 0.05) average daily feed intake (ADFI), the degree of redness (a*) in muscles, and serum total superoxide dismutase (T-SOD) level. It also reduced (P < 0.01) average daily gain (ADG), and serum total antioxidant capacity (T-AOC) level, while increasing (P < 0.05) shear force, serum direct bilirubin (D-BIL), uric acid (UA), and malondialdehyde (MDA) levels compared with the control group. Dietary supplementation of VC and Bet, either alone or in combination, significantly decreased shear force and serum UA level, while increasing ADG and serum T-AOC, T-SOD level compared with the HS group (P < 0.05). In conclusion, the addition of VC and/or Bet to the diet proves effective in enhancing the growth performance of HS-exposed broilers through the positive regulation of serum chemical metabolism and the alleviation of oxidative damage.

Bioinspired Zwitterionic Nanowires with Simultaneous Biofouling Reduction and Release.

Marine biofouling is a complex and dynamic process that significantly increases the carbon emissions from the maritime industry by increasing drag losses. However, there are no existing non-toxic marine paints that can achieve both effective fouling reduction and efficient fouling release. Inspired by antifouling strategies in nature, herein, a superoleophobic zwitterionic nanowire coating with a nanostructured hydration layer is introduced, which exhibits simultaneous fouling reduction and release performance. The zwitterionic nanowires demonstrate >25% improvement in fouling reduction compared to state-of-the-art antifouling nanostructures, and four times higher fouling-release compared to conventional zwitterionic coatings. Fouling release is successfully achieved under a wall shear force that is four orders of magnitude lower than regular water jet cleaning. The mechanism of this simultaneous fouling reduction and release behavior is explored, and it is found that a combination of 1) a mechanical biocidal effect from the nanowire geometry, and 2) low interfacial adhesion resulting from the nanostructured hydration layer, are the major contributing factors. These findings provide insights into the design of nanostructured coatings with simultaneous fouling reduction and release. The newly established synthesis procedure for the zwitterionic nanowires opens new pathways for implementation as antifouling coatings in the maritime industry and biomedical devices.

An Equalized Flow Velocity Strategy for Perovskite Colloidal Particles in Flexible Perovskite Solar Cells.

The non-uniform distribution of colloidal particles in perovskite precursor results in an imbalanced response to the shear force during flexible printing process. Herein, it is observed that the continuous disordered migration occurring in perovskite inks significantly contributes to the enlargement of colloidal particles size and diminishes the crystallization activity of the inks. Therefore, a molecular encapsulation architecture by glycerol monostearate to mitigate colloidal particles collisions in the precursor ink, while simultaneously homogenizing the size distribution of perovskite colloids to minimize their diffusion disparities, is devised. The utilization of colloidal particles with a molecular encapsulation structure enables the achievement of uniform deposition during the printing process, thereby effectively balancing the crystallization rate and phase transition in the film and facilitating homogeneous crystallization of perovskite films. The large-area flexible perovskite device (1.01 cm2 and 100 cm2) fabricated through printing processes, achieves an efficiency of 24.45% and 15.87%, respectively, and manifests superior environmental stability, maintaining an initial efficiency of 91% after being stored in atmospheric ambiences for 150 days (unencapsulated). This work demonstrates that the dynamic evolution process of colloidal particles in both the precursor ink and printing process represents a crucial stride toward achieving uniform crystallization of perovskite films.

Comparative Study of the Tribocorrosion Performance of NiTiNOL60 in Acidic, Alkaline, and Saline Environments

AbstractIn order to enhance the durability of tribological interfaces, an investigation into the synergistic effects of sliding wear, corrosion, and their interactions is crucial. This study focuses on understanding the deformation mechanisms of NiTiNOL60, a nickel-rich nickel-titanium alloy, during sliding against Al2O3 in different corrosive environments, including acidic, alkaline, and saline mediums. The pH of the environments is found to play a significant role in the tribocorrosion process, leading to electromechanically induced transformations and various wear patterns. Plastic deformations are observed on the wear track surfaces, particularly in the severe and mild wear regimes. In an alkaline environment, depassivation of the oxide layer triggers oxidational wear, with the depassivation rate dependent on factors like contact pressure, sliding velocity, and passive film properties. The wear volume is highest in saline environments, with contributions from mechanical wear, corrosion, and third-body abrasion. Grain deformations occur in the alkaline environment due to shear forces, while in the acidic medium, corrosion accelerates mild wear involving abrasion and delamination. The findings provide insights into wear mechanisms and localized corrosion, highlighting the influence of H+ and OH− groups (pH values) on corrosive wear and crack propagation.

Modified Scalp Replantation for Total Scalp Avulsion: Scalp-Shifting Technique.

Scalp replantation is the best treatment for scalp avulsion due to its functional and esthetic benefits. Regular scalp replantation requires only unilateral or bilateral superficial temporal vascular anastomosis. However, shear force always damages vessels in severe scalp avulsions. Short, superficial temporal vessels (STVs) make tension-free anastomosis challenging. The objective of this article is to improve the regular scalp replantation technique. When the STVs are short, tension-free anastomosis, and cosmetic symmetry can be achieved without vein grafts or vascular replacement. This study retrospectively reviewed 18 patients with scalp avulsion, of which 10 underwent scalp-shifting replantation, and 8 underwent regular scalp replantation with direct anastomosis of the STVs. Postoperatively, the authors, assessed whether there was a significant difference in the percentage of scalp survival and in the facial symmetry of patients between the 2 methods. The percentages of scalp survival and facial symmetry were good after surgeries using both methods, and no significant differences were observed. The authors use scalp-shifting replantation to create tension-free anastomoses in cases where scalp avulsion injuries have left the superficial temporal arteries too short. This technique ensures facial symmetry, scalp reimplantation survival, and equally excellent results in function and esthetics.