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This paper aims to study the corrosion resistance and interfacial bonding properties of the silver zinc-rich coating/substrate system and silicone zinc-rich coating/substrate system. The actual working state of the system in marine environment was simulated by the coupled effects of corrosion and pre-stretching. Scanning electron microscope (SEM) with an energy dispersive X-ray spectrometer (EDS) was used in corrosion test to analyze the surface morphology and corrosion products. Meanwhile, the degradation degree of the corrosion resistance was investigated based on the electrochemical impedance spectroscopy (EIS) and water absorption rate. Three-point bending test and tensile test combined with digital image correlation (DIC) were performed to evaluate the interfacial bonding properties of these two systems based on the elastic modulus and critical cracking strain. Results show that the dense accumulation of aluminum and zinc powders makes the silver zinc-rich coating have higher corrosion resistance compared to the silicone zinc-rich coating. The combined effects of corrosion and pre-stretching on the fracture toughness of silicone zinc-rich coating are larger than that of the silver zinc-rich coating. The interfacial bonding properties of the coating/substrate systems gradually degrade as the pre-stretching load approaches the critical cracking load of the coating. [ABSTRACT FROM AUTHOR]

Background: Aphis gossypii Glover (Hemiptera: Aphididae) is an economically important polyphagous pest species infesting many agricultural and horticultural crops causing severe yield losses. In order to develop biopesticides for the management of aphids in an environmentally safe manner, 6 indigenous entomopathogenic fungi Simplicillium subtropicum were isolated from soils of Tamil Nadu and their pathogenicity was tested against A. gossypii under laboratory conditions after characterization. Results: Phenotypic and molecular characterization was performed for all the isolates for species identification. Results of the pathogenicity test showed that the isolate S6 (PP446637) performed well among other isolates causing 58.33% mortality on 7 days after treatment (DAT) @ 1 × 108 spores/ml. The LC50 and LT50 values were found to be 2.36 × 107 spores/ml at 7 DAT and 160.20 h @ 1 × 108 spores/ml, respectively. SEM images of A. gossypii treated with the isolate S6 (PP446637) revealed that initial phase of infection, i.e., adhesion, formation of germ tube and appressoria starts within 24 h post-infection (hpi), hyphal development and penetration of cuticle occurred within 48 hpi and extrusion of mycelium and conidiogenesis occurred within 72 hpi. Conclusion: This study reveals the entomopathogenic potential of indigenous S. subtropicum isolates against A. gossypii and suggests their use for the eco-friendly management of aphids. [ABSTRACT FROM AUTHOR]

• Investigating Bipolaris maydis interaction with maize genotypes revealed varying levels of resistance and susceptibility. • Scanning electron microscopy showed stomatal pattern variations, correlating with mycelium invasion and symptom severity. • ABA quantification during infection showed lower ABA levels in resistant varieties, linked to a balanced defense response. • Resistant variety S-2022-11356 showed multiple mechanisms: physical barriers, reduced mycelium, unique stomata, and lower ABA levels. • Findings are significant for breeding programs and managing foliar diseases, emphasizing strategies for enhanced maize resistance. Bipolaris maydis is a prominent pathogen causing maydis leaf blight disease (MLB) in warm, humid regions worldwide. Structural components of plants, particularly stomata, play a crucial role in defending against pathogen invasion. In this study, we conducted a comprehensive investigation of stomatal interactions at the histopathological and molecular levels in various cultivated maize genotypes from Punjab state of India. Bipolaris maydis was isolated, purified, and inoculated onto six maize genotypes. Leaf samples were collected 48 h post-inoculation, representing the disease phase. Stomatal aperture bioassays and scanning electron microscopy (SEM) were performed on infected and non-infected samples. SEM analysis revealed distinct morphological variations, including stomatal aperture patterns and MLB pathogen invasion routes through stomata. Stomatal diameter varied among genotypes, and mycelium presence on the leaf surface was observed, with varying degrees of invasion through stomata. Genotypes exhibiting greater field symptom visibility displayed higher mycelium abundance and invasion. Additionally, high-performance liquid chromatography (HPLC) was employed to quantify abscisic acid (ABA) content in maize leaves during the Bipolaris maydis -maize interaction. This analysis aimed to elucidate the relationship between ABA and biotic stress, shedding light on its role in defense responses against the pathogen. Overall, our study enhances the understanding of stomatal interactions, surface morphology, and ABA dynamics in maize- Bipolaris maydis interactions. These findings have implications for breeding programs seeking to develop resistant maize varieties and contribute to the overall management of MLB disease. These findings provide valuable insights for future breeding programs targeting resistance against maize pathogens. [ABSTRACT FROM AUTHOR]

This study addresses the growing need for sustainable construction materials by investigating the mechanical properties and behavior of palm fiber-reinforced cementitious composite (FRCC), a potential eco-friendly alternative to synthetic fiber reinforcements. Despite the promise of natural fibers in enhancing the mechanical performance of composites, challenges remain in optimizing fiber distribution, fiber–composite bonding mechanism, and its balance to matrix strength. To address these challenges, this study conducted extensive experimental programs using palm fiber as reinforcement, focusing on understanding the fiber–matrix interaction, determining the pullout load–slip relationship, and modeling fiber bridging behavior. The experimental program included density calculations and scanning electron microscope (SEM) analysis to examine the surface morphology and diameter of the fibers. Single fiber pullout tests were performed under varying conditions to assess the pullout load, slip behavior, and failure modes of the palm fiber, and a relationship between the pullout load and slip with the embedded length of the palm fiber was constructed. A trilinear model was developed to describe the pullout load–slip behavior of single fibers, and a corresponding palm-FRCC bridging model was constructed using the results from these tests. Section analysis was conducted to assess the adaptability of the modeled bridging law calculations, and the analysis result of the bending moment–curvature relationship shows a good agreement with the experimental results obtained from the four-point bending test of palm-FRCC. These findings demonstrate the potential of palm fibers in improving the mechanical performance of FRCC and contribute to the broader understanding of natural fiber reinforcement in cementitious composites. [ABSTRACT FROM AUTHOR]

Background: Our research is the first to explore the ultrastructural features of the lingual papillary system of Arab Zebu cattle, highlighting their Chadian environmental adaptations. Results: There were two types of papillary systems: gustatory (fungiform and circumvallate) and mechanical (filiform, conical, and lentiform). The dorsal surface of the apex and rostral parts of the body had well-developed filiform papillae, whereas the tip's surface had mucosal folds, tubercles, and few filiform papillae. The torus lingua's dorsal surface displayed few lentiform papillae, while two conical papillae subtypes and numerous circumvallate papillae were present on its lateral surfaces. A slight median ridge on the dorsal surface of the body had not been described previously. Six filiform papillae subtypes were identified: long and rod-like on the tip; tongue-like and elongated on the lateral area of the apex and body; transient conical and leaf-like on the median line. The accessory processes were: one pair (on long, tongue-like, and transient conical), two pairs (on leaf-like and elongated), and four pairs on the large conical papillae. The two fungiform papillae subtypes were surrounded by a groove and had taste pores (3–5 on the oval and 5–9 on the round papillae). The U-shaped annular bad were observed around the ovoid circumvallate papillae, and the circular bad were observed around the round ones. The circumvallate had taste pores (8–14 on the round's dorsal and lateral surfaces and 6–10 on the ovoid's lateral surface). Conclusion: The papillary system's regional divergence was specialized for its harsh and semi-harsh diet. [ABSTRACT FROM AUTHOR]

The world race in scientific research in the fields of petroleum and how petroleum is transported to another place has inspired our scientific curiosity to research the welding bead of petroleum pipelines. This paper is an experimental examination of the response to the effect of heat treatments on the mechanical and microstructure properties of welded API X70 steel. Our study investigates how heat treatments altered the microstructure and mechanical properties of the fusion zone (FZ) in welded pipe steel of grade API X70. It shows microstructures achieved after one heat treatment at 550℃ for 1h, 2h, 3h, 4h and 5h. A metallographic test by the optical microscope and the scanning electron microscope (SEM) as well as the analysis of the samples by X-ray diffraction (XRD) and the measurement of the hardness test was applied to all the samples prepared. The results revealed that the isothermal heat treatment caused grain growth and coarsening reactions in the weld zone and the hardness of weld joints decreased were the main transformations after increasing the temperature of the heat treatment. [ABSTRACT FROM AUTHOR]

The main objective of this paper is to investigate the impact splitting tensile property and microstructure characteristics of steel fiber recycled aggregate concrete (SFRAC) based on the split Hopkinson pressure bar (SHPB) and scanning electron microscope (SEM). The effects of fiber content, strain rate, and recycled aggregate replacement ratio on the mechanical parameters (static and dynamic splitting tensile strength, peak strain and ultimate strain, peak toughness and ultimate toughness) were analyzed. Then the microstructure characteristics of SFRAC at different interfaces were observed via SEM, and energy spectrum analysis of the interface transition zone (ITZ) was carried out. The results show that SFRAC is a strain-rate sensitive material whose mechanical properties are affected by the strain rate and improved with its increase. It is also found that steel fibers play a role in improving dynamic splitting tensile strength and toughness, and the optimal fiber content is about 1.0%. However, increasing the recycled aggregate replacement ratio will weaken the good effect of steel fibers on the mechanical properties. Furthermore, it can be seen by means of SEM that the fracture area of steel fiber is mostly pulled out. Also, there are more cracks and pores in the cement paste of recycled aggregate concrete (RAC) compared with normal concrete (NC), and the hydration products in the ITZ are significantly decreased. With the incorporation of steel fibers, the calcium content of the ITZ can be reduced. [ABSTRACT FROM AUTHOR]

Abstract Background Aphis gossypii Glover (Hemiptera: Aphididae) is an economically important polyphagous pest species infesting many agricultural and horticultural crops causing severe yield losses. In order to develop biopesticides for the management of aphids in an environmentally safe manner, 6 indigenous entomopathogenic fungi Simplicillium subtropicum were isolated from soils of Tamil Nadu and their pathogenicity was tested against A. gossypii under laboratory conditions after characterization. Results Phenotypic and molecular characterization was performed for all the isolates for species identification. Results of the pathogenicity test showed that the isolate S6 (PP446637) performed well among other isolates causing 58.33% mortality on 7 days after treatment (DAT) @ 1 × 108 spores/ml. The LC50 and LT50 values were found to be 2.36 × 107 spores/ml at 7 DAT and 160.20 h @ 1 × 108 spores/ml, respectively. SEM images of A. gossypii treated with the isolate S6 (PP446637) revealed that initial phase of infection, i.e., adhesion, formation of germ tube and appressoria starts within 24 h post-infection (hpi), hyphal development and penetration of cuticle occurred within 48 hpi and extrusion of mycelium and conidiogenesis occurred within 72 hpi. Conclusion This study reveals the entomopathogenic potential of indigenous S. subtropicum isolates against A. gossypii and suggests their use for the eco-friendly management of aphids.

Abstract Background Our research is the first to explore the ultrastructural features of the lingual papillary system of Arab Zebu cattle, highlighting their Chadian environmental adaptations. Results There were two types of papillary systems: gustatory (fungiform and circumvallate) and mechanical (filiform, conical, and lentiform). The dorsal surface of the apex and rostral parts of the body had well-developed filiform papillae, whereas the tip’s surface had mucosal folds, tubercles, and few filiform papillae. The torus lingua’s dorsal surface displayed few lentiform papillae, while two conical papillae subtypes and numerous circumvallate papillae were present on its lateral surfaces. A slight median ridge on the dorsal surface of the body had not been described previously. Six filiform papillae subtypes were identified: long and rod-like on the tip; tongue-like and elongated on the lateral area of the apex and body; transient conical and leaf-like on the median line. The accessory processes were: one pair (on long, tongue-like, and transient conical), two pairs (on leaf-like and elongated), and four pairs on the large conical papillae. The two fungiform papillae subtypes were surrounded by a groove and had taste pores (3–5 on the oval and 5–9 on the round papillae). The U-shaped annular bad were observed around the ovoid circumvallate papillae, and the circular bad were observed around the round ones. The circumvallate had taste pores (8–14 on the round’s dorsal and lateral surfaces and 6–10 on the ovoid’s lateral surface). Conclusion The papillary system’s regional divergence was specialized for its harsh and semi-harsh diet.

Abstract Visual examination of the surface topography, in conjunction with the other sensors, may confirm the existence of chatter. Online chatter detection during real machining operations is possible with the use of sensors, and the presence of noise in their output and restricted bandwidth are the major drawbacks of these sensors. Productivity drops and manufacturing costs go up when there is a lot of chatter in the machining process. In the present paper, an integrated spindle tool system is modeled using finite element method with Timoshenko beam theory including rotational and shear deformation effects. To maximize the average stable depth of cut in an end milling process while simultaneously minimizing the chatter vibration levels, real time and offline strategies have been investigated. Machining experiments performed on Al6061-alloy specimens provide an empirical confirmation of the stability boundaries. The surface topography methods such as scanning electron microscope (SEM) and optical microscope images along with vibration levels are considered, to identify chatter marks under various machining conditions, which helps to assure cutting process stability. Stability lobe diagrams are plotted with these derived conditions and observed at an incremental level in the axial depths of the cut. The methodology shown in this paper improves the machining stability of the end milling with the reduction in the tool tip vibrations.

Visual examination of the surface topography, in conjunction with the other sensors, may confirm the existence of chatter. Online chatter detection during real machining operations is possible with the use of sensors, and the presence of noise in their output and restricted bandwidth are the major drawbacks of these sensors. Productivity drops and manufacturing costs go up when there is a lot of chatter in the machining process. In the present paper, an integrated spindle tool system is modeled using finite element method with Timoshenko beam theory including rotational and shear deformation effects. To maximize the average stable depth of cut in an end milling process while simultaneously minimizing the chatter vibration levels, real time and offline strategies have been investigated. Machining experiments performed on Al6061-alloy specimens provide an empirical confirmation of the stability boundaries. The surface topography methods such as scanning electron microscope (SEM) and optical microscope images along with vibration levels are considered, to identify chatter marks under various machining conditions, which helps to assure cutting process stability. Stability lobe diagrams are plotted with these derived conditions and observed at an incremental level in the axial depths of the cut. The methodology shown in this paper improves the machining stability of the end milling with the reduction in the tool tip vibrations. [ABSTRACT FROM AUTHOR]

In present study mass loss behaviour of base metal and heat-treated API X70 pipeline steel in different environments such as fresh water, sea water and sodium thiosulphate medium were observed for 50 days. Corrosion is the main failure in pipeline steel which need to be reduced with the use of suitable heat treatment process. In present study two heat treatment such as HT-1 900 °C (2 hour) with tempering at 450 °C (4 hour) and HT-2 800 °C (2 hour) with tempering at 450 °C (4 hour) was used. Mechanical, microstructure and corrosion rate of HT-1 and HT-2 specimen in different environments were observed. Maximum corrosion rate (0.306 mm/y) in fresh water while minimum corrosion rate (0.181 mm/y) in sodium thiosulphate medium was observed for base metal. Maximum corrosion rate (0.224 mm/y) in sodium thiosulphate while minimum corrosion rate (0.106 mm/y) in fresh water medium was observed for HT-1 specimen. For HT-2 specimen, Maximum corrosion rate (0.192 mm/y) in sea water while minimum corrosion rate (0.099 mm/y) in fresh water medium was observed. For HT-2 specimen, maximum average hardness of (30.3 HRC) in sea water while minimum average hardness of (28 HRC) of base metal was observed. In fresh water also HT-2 specimen, maximum average hardness is (26.3 HRC) while minimum average hardness of (24.6 HRC) of base metal was observed. After that maximum average hardness of base metal (26.6 HRC) in sodium thiosulphate while minimum average hardness of (21 HRC) of HT-2 specimen was observed. [ABSTRACT FROM AUTHOR]

Background: Escalating global plastic production, expected to reach 34,000 million tons by 2050, poses a significant threat to human and environmental well-being, particularly in aquatic ecosystems. Microplastics (MP) and nanoplastics (NP), which originate from the degradation of plastics, are of concern due to their potential bioaccumulation and uptake of pollutants. This study addresses identification methods and focuses on insect meal, a raw material for aquaculture feed. Methods: By using different techniques, the study was able to detect MP and NP in insect meal samples. Chemical digestion with KOH at 60 °C efficiently removed organic matter without affecting the synthetic polymer polyethylene (PE). Filtration, confocal Raman microscopy, SEM, and TEM were used for comprehensive analysis, and integrity tests on PE films were performed using Raman and FTIR spectroscopy. The results showed the presence of PE microplastic particles in the insect meal, which was confirmed by correlative Raman and SEM mapping on a positively charged surface. In addition, the increased resolution of the Raman microscope identified submicrometric PE NP (800 nm). Transmission electron microscopy (TEM) with energy-dispersive X-ray spectroscopy (EDX) confirmed plastic-like structures in the insect meal, highlighting the presence of PE plastics characterized by irregular shapes and some agglomeration. The higher carbon concentration in the EDX analysis supported the plastic nature, which was also confirmed by Raman spectroscopy. Conclusions: The study provides a robust method for the detection of MP and NP in insect meal and provides valuable insight into the possible presence of plastics in insect-based aquafeeds. The combination of different analytical methods increases the reliability of the results and sets the stage for future investigations that could focus on the quantification of NP and the assessment of their potential environmental impact. [ABSTRACT FROM AUTHOR]

When the first concrete was poured in 1949 for the Hungry Horse Dam (Montana, USA), pozzolan cements had already been used in several major North American dams, including Grand Coulee on the Columbia River (diatomaceous earth explored but ultimately not used), Friant on the San Joaquin River and Altus on the North Fork Red River (pumicite) and Bonneville on the Columbia River and Davis on the Colorado River (calcined clay). But Hungry Horse Dam stands out as the first dam constructed using coal combustion fly ash. Utilising 2.4 million cubic metres of concrete, the dam is located on the South Fork Flathead River, one of the tributaries feeding one of the nation's major waterways, the Columbia River, and closely related to the adjacent Glacier National Park. In this respect, Hungry Horse is directly connected to two momentous periods in modern history – the massive adoption in the 1950s of coal as fuel for power plants, and the ongoing threats to fresh water supply and the rapid retreat of alpine glaciers due to global warming. Two concrete cores from this dam, one with fly ash and one without fly ash, are examined microscopically to explore the long‐term suppression of alkali‐aggregate reaction by fly ash. The core without fly ash exhibits clear evidence of alkali‐aggregate reaction, manifested by sandstone coarse aggregate particles with darkened reaction rims. Sandstone coarse aggregate particles of the same lithology in the core with fly ash are without signs of alkali‐aggregate reaction. A detailed examination of the darkened rims indicates that alkali‐silica reaction products fill the narrow gaps between adjacent sand grains in the sandstone. This alkali‐silica gel infilling allows for optical continuity between adjacent sand grains and is responsible for the classic darkened rim associated with the alkali‐aggregate reaction. [ABSTRACT FROM AUTHOR]

In recent times, with rapid development in the construction sector, the use of enormous amounts of materials is required for the production of concrete. Fire penetrates concrete, leading to chemical contamination, small cracks, and lightening. These effects can significantly change the properties of concrete's structure, reduce its strength and durability, and also change the behavior of the structure and lead to effects on the environment. An attempt was made to study the effects of elevated temperature on the mechanical characteristics of self-compacting concrete (SCC) with by-products including fly ash as a partial replacement for cement and waste copper slag as a partial replacement for fine aggregate at 0%, 10%, 20%, 30%, 40%, 50%, 60%, and 70%. The SCC specimens were subjected to elevated temperatures ranging from 200, 400, 600, and 800 °C, respectively, for a steady-state of two hours in a digital muffle furnace. The residual compressive strength, mass loss, ultrasonic pulse velocity, and residual density along with a visual inspection of cracks and color changes were observed. In this study, with over 400 °C temperatures, surface fractures appeared. The residual compressive strength (R-CMS) of all the individual temperatures of the SCC-WCS% mixes exhibited a gain in strength range from 31 to 34 MPa at 400 °C, 26 to 35 MPa at 600 °C, and 22.5 MPa to 33.5 MPa at 800 °C, respectively. Microstructural analysis of SCC-WCS% mixtures subjected to elevated ambient temperatures is carried out with a scanning electron microscope (SEM) and X-ray diffraction (XRD). [ABSTRACT FROM AUTHOR]

Previous research has individually demonstrated the successful waste recycling of Municipal Incineration Bottom Ash (MIBA) and Electric Arc Furnace Slag (EAFS) for tile making. This study explored a new frontier of combining both MIBA and EAFS to produce quality floor and wall tiles. EAFS was introduced to reinforce strength and address the quality issues associated with MIBA tiles. Tile samples were formulated with different combinations of MIBA, EAFS, and clay, subjected to various kiln firing temperatures. Findings indicated that the inclusion of EAFS led to enhanced tile water absorption and bending strength, particularly at a firing temperature of 1150℃. The integration of EAFS played a pivotal role in consolidating tile structure, mitigating gas release, and reducing internal porosity during crystallization phase. Through the utilization of 30% MIBA and 3% EAFS, tiles that conform to class Ib standards were successfully manufactured. Additionally, the study highlighted that the addition of 9% EAFS alone could elevate the tiles to meet class Ia standards if no MIBA was added. [ABSTRACT FROM AUTHOR]

Abstract Most vegetable crops are severely affected by the uptake of heavy metals from the soil. Heavy metals in vegetable bodies generate reactive oxygen species (ROS) that unbalance the antioxidant defense system. This study was initiated to determine the physiological and biochemical characteristics of spinach plants grown on soil contaminated with heavy metals and responding to Bacillus cereus and Bacillus aerius were isolated from soil contaminated with heavy metals. Heavy metal contamination led to a significant reduction in seed germination, seedling biomass, protein, and total nitrogen content of spinach plants grown in contaminated soils compared to control soils. In contrast, a significant increase in the content of metallothioneins and antioxidant enzymes was observed. Plants inoculated with B. cereus and B. aerius significantly reduced the oxidative stress induced by heavy metals by improving seed germination (%), seedling growth, nitrogen, and protein content. The content of metallothioneins and the activities of antioxidant enzymes were reduced in spinach plants grown from seeds inoculated with bacterial strains. In addition, plants inoculated with, B. cereus and B. aerius showed greater stomata opening than plants grown on soil contaminated with heavy metals, whose stomata were almost closed. These results suggested that both bacterial strains enhanced plant growth by reducing oxidative stress caused by metals.

Legumes are consumed in various foods, and people frequently expect desirable characteristics from them, such as low cooking times, which minimizes the time and energy required for consuming legumes. Here, we aimed to investigate the activation energy and water adsorption behavior of different combinations of temperatures and times by soaking and cooking adzuki beans. Soaking at 30 °C produced a high-water adsorption balance rate of 98.99 %. Soaking reduced the gelatinization of adzuki bean starch. Furthermore, scanning electron microscopy revealed that, after crushing and filtering separated cotyledon cells, called “bean paste”, the process of soaking and cooking could significantly impact the process and quality of the bean paste. Alternatively, it could maintain a high yield by decreasing bean damage and tissue cracking during cooking. Hence, the results might be used to minimize the processing time, save energy, and improve the product quality of adzuki beans.

In order to study the effects of molding process on the macroscopic performances of cement stabilized gravel, based on two kinds of gradation of skeleton compaction and suspension compaction, eight kinds of cement stabilized gravel were prepared by four kinds of processes: static compaction molding with forced mixing, vibratory compaction with forced mixing, static compaction molding with vibratory mixing, and vibratory compaction with vibratory mixing. Furthermore, the macro-performances of cement stabilized gravel were investigated by adopting the 7 d unconfined compression test, the 28 d single-axis penetration test, the 7 d warming shrinkage test, and the 7 d drying shrinkage test. The underlying microscopic mechanism of the macroscopic property variation of the cement stabilized gravel was analyzed by combining with the microscopic means of scanning electron microscope. The results show that the mechanical properties of cement stabilized gravel with skeleton dense grading under vibration mixing and vibration compaction process are optimal, and its 7 d unconfined compressive strength and 28 d uniaxial compression modulus are improved by 169. 5% and 97. 2%, respectively, compared with that of forced mixing and static compression molding. The vibration mixing vibration compaction techniques can improve the macro performance of cement stabilized crushed stone in terms of promoted the cement hydration product generation, perfect structure, and elevated overall uniformity. [ABSTRACT FROM AUTHOR]

Most vegetable crops are severely affected by the uptake of heavy metals from the soil. Heavy metals in vegetable bodies generate reactive oxygen species (ROS) that unbalance the antioxidant defense system. This study was initiated to determine the physiological and biochemical characteristics of spinach plants grown on soil contaminated with heavy metals and responding to Bacillus cereus and Bacillus aerius were isolated from soil contaminated with heavy metals. Heavy metal contamination led to a significant reduction in seed germination, seedling biomass, protein, and total nitrogen content of spinach plants grown in contaminated soils compared to control soils. In contrast, a significant increase in the content of metallothioneins and antioxidant enzymes was observed. Plants inoculated with B. cereus and B. aerius significantly reduced the oxidative stress induced by heavy metals by improving seed germination (%), seedling growth, nitrogen, and protein content. The content of metallothioneins and the activities of antioxidant enzymes were reduced in spinach plants grown from seeds inoculated with bacterial strains. In addition, plants inoculated with, B. cereus and B. aerius showed greater stomata opening than plants grown on soil contaminated with heavy metals, whose stomata were almost closed. These results suggested that both bacterial strains enhanced plant growth by reducing oxidative stress caused by metals. [ABSTRACT FROM AUTHOR]

The MCrAlY bonding layer alloy was prepared by vacuum melting, and the alloy composition was NiCoCrAlY and NiCoCrAlYHfTa. The high-temperature cyclic oxidation experiment was carried out in air at 1050∘C until it failed. The results show that Hf and Ta have a significant influence on the oxidation resistance of the alloy. The doped specimens have longer oxidation lifetimes compared to the undoped samples. The study also found that the Hf would diffuse out and combine with O to form HfO2 in the thermally grown oxide (TGO) layer, which would improve the adhesion and reduce the wrinkles of the oxide layer. Ta in the doped specimens hinders the diffusion of Al and reduces the oxidation rate, while improving the thermal mismatch. Therefore, the specimens doped with both Hf and Ta have the highest oxidation lifetimes, though the oxidation lifetime was 10 times longer than that of the undoped specimens. It is indicated that the doping of Hf and Ta is an important method to improve the oxidation lifetime of thermal barrier coatings (TBCs). [ABSTRACT FROM AUTHOR]

This paper presents research about a mixture design method of pavement concrete coblending rubber and fiber into ordinary concrete. Mechanical-based tests regarding the compressive strength, elastic modulus, splitting tensile strength, flexural strength, and four-point bending stiffness were conducted to evaluate the flexural toughness of concrete, and a slab-based three-point bending test was designed to evaluate the bending toughness improvement of the road pavement concrete slab. The results indicated that with the increase in single rubber content, the compressive strength and elastic modulus of concrete decreased continuously. The rubber concrete specimen remained relatively complete in appearance during destruction, showing the satisfied ductile failure characteristics to pavement usage with the optimal rubber content of 10%. After adding basalt fiber (BF) or polypropylene fiber (PPF), with the increase of fiber content, the bending stiffness of concrete decreased, the corresponding deflection of peak load increased continuously, and the bending deformation capacity of concrete could be significantly enhanced. Compared with the reference group, when the rubber content is 10%, and basalt fiber content is 0.5%–2%, the equivalent initial bending strength of fiber-reinforced rubber concrete is increased by 105.4%–164.4%. In general, BF is better than PPF in improving the toughness of rubber concrete, and the optimal dosage of BF is 1% of concrete volume in this test. When loaded to the limit load, the deflection of the basalt fiber–reinforced rubber concrete slab in the middle of the bottom span was about four times higher than that of the benchmark concrete slab, the bending deformation capacity and toughness of the basalt fiber–reinforced rubber cement concrete slab have been greatly improved. From the test results, the mixture design method of flexible pavement cement concrete based on rubber and fiber coblending was proposed, which contributes to the development of flexible materials for concrete pavement. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the lateral crashworthiness performance of thin-walled circular glass fiber-reinforced epoxy (GFRE) tubes filled with various silicon carbide (SiC) nanoparticles weight percent (wt.%). The wet wrapping hand layup process was used to create GFRE tubes that were filled with 1, 2, 3, and 4 wt.% of SiC. For the laterally loaded tubes, the crushing load and absorbed energy versus displacement responses were displayed. In addition, deformation histories were monitored. As part of the crashworthiness analysis, the energy absorbed (EA) and specific absorbed energy (SEA) were evaluated. Two parameters of the Weibull distribution were working to evaluate the experimental results statistically. Overall research exposed that up to 2 wt.% of SiC, both EA and SEA are improved; after that, a visible reduction is observed. [ABSTRACT FROM AUTHOR]

Multielectrode arrays for interfacing with neurons are of great interest for a wide range of medical applications. However, current electrodes cause damage over time. Ultra small carbon fibers help to address issues but controlling the electrode site geometry is difficult. Here we propose a methodology to create small, pointed fiber electrodes (SPFe). We compare the SPFe to previously made blowtorched fibers in characterization. The SPFe result in small site sizes $(105.4 \pm 20.8~\mu \text{m}^{{2}})$ with consistently sharp points (20.8 ± 7.64°). Additionally, these electrodes were able to record and/or stimulate neurons multiple animal models including rat cortex, mouse retina, Aplysia ganglia and octopus axial cord. In rat cortex, these electrodes recorded significantly higher peak amplitudes than the traditional blowtorched fibers. These SPFe may be applicable to a wide range of applications requiring a highly specific interface with individual neurons.

In this study, silver nanoparticles (AgNPs) were synthesized in an environmentally friendly manner using plant extracts from Luisia tristis. The formation of the nanoparticles was confirmed by a reddish-brown colour change and further characterized using ultraviolet–visible (UV–Vis), Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM), and transmission electron microscope (TEM) techniques. The average size of the particles was found to be 16–48 nm. The antimicrobial activity of the AgNPs was evaluated against harmful bacteria and compared to the commonly used antibiotic ciprofloxacin. The AgNPs were found to be highly effective, with a 24 mm zone of inhibition against Escherichia coli, and more effective than ciprofloxacin. Additionally, a minimum inhibitory concentration assay was performed with a concentration of 100 mg/mL of AgNPs, which were found to effectively inhibit the growth of selected pathogens. Overall, the study demonstrates the potential for using plant-derived AgNPs as a natural and eco-friendly alternative for antimicrobial and antioxidant applications. This method is a fast, cost-effective way to generate silver nanoparticles at room temperature and may be useful in creating environmentally friendly antibacterial solutions for biomedical applications.

AbstractBiodegradation of used engine oil (UEO) that pollutes the environment is attracting increasing attention. The aim of this study was to characterize the adsorption of used engine oil (UEO) and the immobilization of UEO biodegraders in Ochrobacterium intermedium LMG 3301 and Ochrobacterium intermedium LMG 3301 plus Bacillus paramycoides MCCC1A04098 (BC) using alginate-attapulgite-calcium carbonate (AAC). Twenty AAC beads were tested separately in 20 mL of soil water extract (SWE) and hexane containing 1% UEO for their adsorptive capacities of UEO in 50-mL capped flasks. The results showed that the UEO removal efficiency (%RE) was bead-number dependent, recording a maximum of 83 ± 0.32% in SWE, and 11.50 ± 0.52% in hexane correlating with the highest number of AAC-granules (20 beads). The 1st order kinetics in SWE showed a UEO adsorption rate, K1 (h−1), of 0.11–0.15 h−1 correlating with 20 AAC-granules and 1, 2, 3 and 4% (w/v) UEO. The intra-particle diffusion kinetic model suggested that intra-diffusion was the main mode of mass transfer in AAC granules. The microscopic study and 2,3,5-triphenyltetrazolium chloride (TTC) positive stain showed that bacteria grew well in AAC. This result demonstrates that this matrix can be applied in the formulation of novel adsorptive granular formulas for bioremediation of UEO.

This study addresses the growing need for sustainable construction materials by investigating the mechanical properties and behavior of palm fiber-reinforced cementitious composite (FRCC), a potential eco-friendly alternative to synthetic fiber reinforcements. Despite the promise of natural fibers in enhancing the mechanical performance of composites, challenges remain in optimizing fiber distribution, fiber–composite bonding mechanism, and its balance to matrix strength. To address these challenges, this study conducted extensive experimental programs using palm fiber as reinforcement, focusing on understanding the fiber–matrix interaction, determining the pullout load–slip relationship, and modeling fiber bridging behavior. The experimental program included density calculations and scanning electron microscope (SEM) analysis to examine the surface morphology and diameter of the fibers. Single fiber pullout tests were performed under varying conditions to assess the pullout load, slip behavior, and failure modes of the palm fiber, and a relationship between the pullout load and slip with the embedded length of the palm fiber was constructed. A trilinear model was developed to describe the pullout load–slip behavior of single fibers, and a corresponding palm-FRCC bridging model was constructed using the results from these tests. Section analysis was conducted to assess the adaptability of the modeled bridging law calculations, and the analysis result of the bending moment–curvature relationship shows a good agreement with the experimental results obtained from the four-point bending test of palm-FRCC. These findings demonstrate the potential of palm fibers in improving the mechanical performance of FRCC and contribute to the broader understanding of natural fiber reinforcement in cementitious composites.

Metal-matrix composites (MMCs) and hybrid metal-matrix composites (HMMCs) are novel materials that possess distinctive mechanical characteristics, making them well-suited for industrial applications. This research implements an experimental study of the mechanical properties of HMMCs, where weight percentages (2, 3, and 4 wt. %) of zirconium dioxide (ZrO2) and graphite powder (Gr) are used as reinforcements and the aluminum alloy 7475 (AA7475) is used as a matrix. In this investigation, the stir casting method was used to prepare the composite by using AA7475 alloy with pre-heated reinforced particles of ZrO2 and graphite with various reinforcement weight percentages. Among these combinations, AA with 4 wt. % ZrO2 and 2 wt.% Gr showed enhanced mechanical properties. The mechanical properties of the ultimate tensile strength, yield strength, and hardness were evaluated. A Scanning Electron Microscope analysis was conducted to study the reinforcement distribution in the matrix. The input parameters for wire-cut electrical discharge machining (WCEDM) are pulse-on time (TON), pulse peak current (IP), and flushing pressure (PF). The material removal rate and surface roughness are the output responses. Determining the ideal set of process parameters in WCEDM for HMMC also involved the use of the Taguchi design technique known as the L9 orthogonal array. The peak current for the MRR and flushing pressure for the SR are the most prominent parameters. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles (AgNPs) were synthesized in an environmentally friendly manner using plant extracts from Luisia tristis. The formation of the nanoparticles was confirmed by a reddishbrown colour change and further characterized using ultraviolet-visible (UV-Vis), Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM), and transmission electron microscope (TEM) techniques. The average size of the particles was found to be 16-48 nm. The antimicrobial activity of the AgNPs was evaluated against harmful bacteria and compared to the commonly used antibiotic ciprofloxacin. The AgNPs were found to be highly effective, with a 24 mm zone of inhibition against Escherichia coli, and more effective than ciprofloxacin. Additionally, a minimum inhibitory concentration assay was performed with a concentration of 100 mg/mL of AgNPs, which were found to effectively inhibit the growth of selected pathogens. Overall, the study demonstrates the potential for using plant-derived AgNPs as a natural and eco-friendly alternative for antimicrobial and antioxidant applications. This method is a fast, cost-effective way to generate silver nanoparticles at room temperature and may be useful in creating environmentally friendly antibacterial solutions for biomedical applications. [ABSTRACT FROM AUTHOR]

Essential oils have proven to possess great potential in the field of biomedicine due to their ability to effectively eradicate a diverse range of pathogenic microbes. In this study, the antimicrobial activity of ylang-ylang essential oil (YY-EO) was screened against twelve multidrug-resistant pathogens. The YY-EO was effective up to 536 μg/ml, with the highest inhibition zone in case of S. aureus MMCC21 and Escherichia coli MMCC24. The least effect on both Bacillus cereus MMCC11 and Klebsiella pneumonia MMCC16. The major components of the essential oil were identified using GC–MS analysis. Different gamma irradiation doses against the YY-EO were evaluated as a tool of natural decontamination. Moreover, the antimicrobial assay after irradiation proved no significant changes regarding the antimicrobial activity before and after irradiation of EO at the applied dose. The minimum inhibitory concentration (MIC) for the EO against the tested pathogens was detected. The possible morphological changes in some of the bacterial and yeast cells at the recognized MIC and 2MIC were detected using the scanning electron microscope (SEM). Results revealed a notable change in terms of both the microbial cell population and the morphology of the tested bacterial and yeast cells. The cytotoxicity of ylang-ylang EO was evaluated against normal skin tissue culture and showed a potential cytotoxic effect at concentrated doses. These results refer to the importance of YY-EO as a natural antimicrobial agent and the possible application of YY-EO as a surface decontaminant, but they also draw attention to the importance of the EO concentration used in different applications to avoid possible toxic effects. [ABSTRACT FROM AUTHOR]

This work focuses on the synthesis of Iron – Copper with reduced graphene oxide (Fe-Cu/rGO) nanocomposites by chemical co-precipitation method and their characterizations by Scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transforms infrared (FTIR), Raman spectroscopy, UV visible spectroscopy and Energy dispersive X-ray (EDX) spectroscopy to investigate the morphology, structural, chemical bonding, optical characteristic and compositional study respectively. Within the Fe-Cu/rGO nanocomposites, the iron concentration ranged from 0 to 100 wt%, while the copper content changed reversibly from 100 to 0 wt% in a step of 20 wt%. SEM images reveal a connective network of grains that varies from 256 nm to 350 nm. The estimated crystallite size ranges from 15.2 nm to 71.3 nm. The micro-strain of Fe-Cu/rGO is altered from 0.00066 to 0.00347. Metal-Oxide (M-O) chemical bond is found shifting to a higher frequency with the addition of iron concentration indicating the increase in backing oxygen and carbon bonding with metal. The carbon defect parameter, ID/IG varied from 1.86 to 1.95 indicating microstructural modification and graphene cluster size decreases with the increase of copper content. The Tauc band gap decreased from 2.68 to 2.14 eV with increased copper content.

The fern genus Microlepia is a natural fern group, while large morphological differences of this genus lead to some classification controversies. The leaf epidermal micromorphology of 18 species (include 3 varieties) of Microlepia was observed and compared under light microscope (LM) and scanning electron microscope (SEM). Hairs were on the veins of the upper and lower epidermis. The form of epidermal cells was irregular, with the anticlinal walls sinuous or sinuate. The stomatal apparatus of all species were restricted to abaxial epidermises and generally could be described as polocytic and axillocytic type, and copolocytic, coaxillocytic, aisocytic and anomotetracytic type only appears in a few species. The similarity of the micromorphological characteristics of leaf epidermis support that the genus Microlepia is a monophyletic group in Dentaedtiaceae. The hairs characteristics between veins of the leaves support that M. calvescens, M. marginata var. villosa and M. marginata var. bipinnata should be treated as a variety of M. marginata. Under SEM, the cuticle of the upper epidermis was mostly ridged, and most of them had filiform ornamentation. The characteristics of leaf cuticle ornamentation were correlated with pinnate compound leaves. The inner margin of the outer stomatal rim was often smooth, sinuous or odontoid. “T” sharp, upright outer stomatal rims occurred in most species, and outer stomatal ledge was mostly depressed. The differences among the leaf micromorphology of these species were shown, which provides references for the classification, evolution and system location of Microlepia.

Abstract Purpose To evaluate collagen scaffolds (CS) in terms of their in vitro resorption behavior, surface structure, swelling behavior, and mechanical properties in physiologically simulated environments, compared with porcine native connective tissue. Materials and methods Three test materials—one porcine collagen matrix (p-CM), two acellular dermal matrices (porcine = p-ADM, allogenic = a-ADM)—and porcine native connective tissue (p-CTG) as a control material were examined for resorption in four solutions using a high-precision scale. The solutions were artificial saliva (AS) and simulated body fluid (SBF), both with and without collagenase (0.5 U/ml at 37 °C). In addition, the surface structures of CS were analyzed using a scanning electron microscope (SEM) before and after exposure to AS or SBF. The swelling behavior of CS was evaluated by measuring volume change and liquid absorption capacity in phosphate-buffered saline (PBS). Finally, the mechanical properties of CS and p-CTG were investigated using cyclic compression testing in PBS. Results Solutions containing collagenase demonstrated high resorption rates with significant differences (p a-ADM > p-ADM. P-CM exhibited higher elastic properties than p-ADM, whereas a-ADM, like p-CTG, were barely compressible and lost structural integrity under increasing pressure. Conclusions and clinical implications Collagen scaffolds vary significantly in their physical properties, such as resorption and swelling behavior and elastic properties, depending on their microstructure and composition. When clinically applied, these differences should be taken into consideration to achieve the desired outcomes. Graphical Abstract

In recent times, with rapid development in the construction sector, the use of enormous amounts of materials is required for the production of concrete. Fire penetrates concrete, leading to chemical contamination, small cracks, and lightening. These effects can significantly change the properties of concrete’s structure, reduce its strength and durability, and also change the behavior of the structure and lead to effects on the environment. An attempt was made to study the effects of elevated temperature on the mechanical characteristics of self-compacting concrete (SCC) with by-products including fly ash as a partial replacement for cement and waste copper slag as a partial replacement for fine aggregate at 0%, 10%, 20%, 30%, 40%, 50%, 60%, and 70%. The SCC specimens were subjected to elevated temperatures ranging from 200, 400, 600, and 800 °C, respectively, for a steady-state of two hours in a digital muffle furnace. The residual compressive strength, mass loss, ultrasonic pulse velocity, and residual density along with a visual inspection of cracks and color changes were observed. In this study, with over 400 °C temperatures, surface fractures appeared. The residual compressive strength (R-CMS) of all the individual temperatures of the SCC-WCS% mixes exhibited a gain in strength range from 31 to 34 MPa at 400 °C, 26 to 35 MPa at 600 °C, and 22.5 MPa to 33.5 MPa at 800 °C, respectively. Microstructural analysis of SCC-WCS% mixtures subjected to elevated ambient temperatures is carried out with a scanning electron microscope (SEM) and X-ray diffraction (XRD).

In the human oral cavity, Streptococcus mutans is often observed and is a major contributor to tooth decay. Increased S. mutans levels may be linked to progressively more severe forms of periodontal disease because root exposure in people with periodontitis increases caries rates. Hence, a new potential antibacterial compound needs to be searched to combat this pathogenic bacterium. The butterfly pea, or Clitoria ternatea is an ornamental plant that has been reported to exhibit antibacterial properties against several bacteria. Thus, the goal of this investigation was to determine how well C. ternatea aqueous (CTA) extract inhibited S. mutans. The disk diffusion assay was performed to access the antibacterial properties of the CTA extract. The efficiency of the extract against the test bacterium was then determined through MIC/MBC determinations and a time-kill study. Meanwhile, the toxicity of the extract was tested using a brine shrimp lethality assay (BSLA). The CTA extract demonstrated substantial antibacterial activity against the test bacterium at a concentration of 200 mg/ml, with a diameter of the inhibition zone of 13.4±0.4 mm, according to the disc diffusion assay. The aqueous extract’s MIC and MBC values were found to be 100 and 400 g/mL, respectively. Time-kill analysis revealed the CTA extract exerted a strong bactericidal effect on S. mutans and this activity was dose-dependent. A scanning electron microscope (SEM) exhibited the bacterial cells experienced severe damage after being exposed to CTA extract including formation cavities, irregular shape, and crumpled cells. Thus, the present study suggested the potential of CTA extract as an antibacterial agent against oral cavity bacteria and can be used in the formulation of natural mouthwash due to no toxicity effect.

Rubberized steel fiber reinforced recycled aggregate concrete (RSRAC) is an environmental-friendly building material produced from waste concrete and tires. However, the evolution of fracture behavior in RSRAC under flexural loads still remains unknown, and the individual as well as the coupling effects of recycled aggregate (RA), crumb rubber, and steel fiber are also unclear. In this paper, four groups of specimens with different contents of RA, crumb rubber, and steel fiber were prepared, and a series of four-point bending tests were conducted. The loading process was monitored by acoustic emission (AE) in real-time, and the fracture behavior was then analyzed through AE signals using multiple statistical methods including Ib-value method, cumulative energy analysis, intensity analysis, K-means clustering and RA-AF analysis. Scanning electron microscope (SEM) was also employed to give explanations in microscale. Results show that the fracture process of RSRAC can be divided into micro-crack stage, main collapse stage, and residual stage. A fluctuation greater than 0.06 in Ib-value could be regarded as a criterion for this division. AE counts, cumulative AE energy as well as cluster analysis are also effective in judging the sub-stages. The dominant failure mode in micro-crack stage and residual stage is tensile crack, and shear cracks mainly occur in the main collapse stage. SEM investigation has revealed that the shear cracks in the main collapse stage mainly come from the shear failure of acicular crystals or micro-chimeras at the interface. For effects of different materials, it is found that rubber can reduce the brittleness and improve the ductility of the concrete, but will lower the strength properties. Steel fiber can increase the brittleness of the fracture behavior and reduce the ductility, but is favorable to strength. While RA can increase the brittleness and is harmful to both ductility and strength. The coexistence of rubber and steel fiber can significantly shorten the residual stage. The work is expected to provide a deeper understanding on the properties of RSRAC.

Purpose: To evaluate collagen scaffolds (CS) in terms of their in vitro resorption behavior, surface structure, swelling behavior, and mechanical properties in physiologically simulated environments, compared with porcine native connective tissue. Materials and methods: Three test materials—one porcine collagen matrix (p-CM), two acellular dermal matrices (porcine = p-ADM, allogenic = a-ADM)—and porcine native connective tissue (p-CTG) as a control material were examined for resorption in four solutions using a high-precision scale. The solutions were artificial saliva (AS) and simulated body fluid (SBF), both with and without collagenase (0.5 U/ml at 37 °C). In addition, the surface structures of CS were analyzed using a scanning electron microscope (SEM) before and after exposure to AS or SBF. The swelling behavior of CS was evaluated by measuring volume change and liquid absorption capacity in phosphate-buffered saline (PBS). Finally, the mechanical properties of CS and p-CTG were investigated using cyclic compression testing in PBS. Results: Solutions containing collagenase demonstrated high resorption rates with significant differences (p < 0.04) between the tested materials after 4 h, 8 h and 24 h, ranging from 54.1 to 100% after 24 h. SEM images revealed cross-linked collagen structures in all untreated specimens. Unlike a-ADM, the scaffolds of p-CM and p-ADM displayed a flake-like structure. The swelling ratio and fluid absorption capacity per area ranged from 13.4 to 25.5% among the test materials and showed following pattern: p-CM > a-ADM > p-ADM. P-CM exhibited higher elastic properties than p-ADM, whereas a-ADM, like p-CTG, were barely compressible and lost structural integrity under increasing pressure. Conclusions and clinical implications: Collagen scaffolds vary significantly in their physical properties, such as resorption and swelling behavior and elastic properties, depending on their microstructure and composition. When clinically applied, these differences should be taken into consideration to achieve the desired outcomes. [ABSTRACT FROM AUTHOR]

In order to analyze the axial compressive properties of ultra-high-toughness cementitious composite (UHTCC)-confined recycled aggregate concrete (RAC), a batch of UHTCC-confined RAC components was designed and manufactured according to the requirements of GB/T50081-2002 specifications. After analyzing the surface failure phenomenon, load-displacement curves, scanning electron microscope (SEM), and parameter analysis of the specimen, the result shows that UHTCC-confined RAC is an effective confinement method, which can effectively improve the mechanical properties and control the degree of surface failure of RAC structures. Compared with the unconfined specimen, the maximum peak load of the UHTCC confinement layer with a thickness of 10 mm and 20 mm increased by 44.61% and 79.27%, respectively, meeting the requirements of engineering practice. Different fiber mixing amounts have different effects on improving the mechanical performance of RAC structural. The specific rule was steel fiber (SF) > polyvinyl alcohol fiber (PVAF) > polyvinyl alcohol fiber (PEF) > no fiber mixture, and the SF improves the axial compression properties of UHTCC most significantly. When there are strict requirements for improving the mechanical properties of the structure, SF should be added to UHTCC. On the contrary, PVAF should be added to UHTCC. [ABSTRACT FROM AUTHOR]

Inconel alloy has been a solution to diverse fields where automobile industry, aircraft, nuclear reactor are the foremost and major applicants of Inconel alloy. But the aim is precise manufacturing in minimum time. Inconel is known for its hard to machine characteristic. This paper illustrates the machining effect on Inconel 601 in EDM. Electrode discharge machining with its ability to machine hard conductive metals is the most recognized and suitable nonconventional machine for the purpose. Experiments with four level of variation and five parameters, (that is, OCV, peak current, pulse on time, duty factor and flushing pressure) have been conducted in 16 different combinations under L16 orthogonal array. Metal removal rate (MRR), surface roughness ( R a ), surface crack density (SCD), and white layer thickness (WLT) have been calculated herein. Surface roughness has been depicted with the help of Taylor Hobson materialize finishing tester. The view of the fact that conventional Taguchi technique cannot be used to solve the multiple response optimization problem independently, so TOPSIS method has been used in this paper to convert multiple responses into an aggregated performance index (called closeness coefficient C i + ) which has been optimized finally by the Taguchi technique. In this, MRR and Ra have been optimized by using the TOPSIS technique and it is found that by using optimal setting i.e. A4B1C2D1E 2 , MRR will be higher while Ra will be lower. Moreover, micro-graphical studies have been conducted to analyze various surface irregularities (SCD and WLT) of EDMed Inconel 601. SCD and WLT have been investigated with respect to optimal settings (A4B1C2D1E2) and obituary settings run no. 10 (A3B2C4D3E1) and better results have been obtained in optimal settings as compared to obituary settings. [ABSTRACT FROM AUTHOR]

In practice, assessing the mechanical behavior of seawater sea sand concrete under severe environmental conditions is urgently needed to evaluate the service life of the prepared concrete. In this paper, the influence of carbonation on the mechanical properties, especially the stress–strain relationship of seawater and sea sand concrete (SSC), sea sand concrete (SC), and ordinary concrete (OC), were investigated by experimental and theoretical means. The microstructural analysis revealed that SSC and SC have higher CO2 sequestration than OC. Although the compressive strength of all concrete specimens increased during the carbonation time, the net increase of compressive strength (excluding cement hydration) contributed by the carbonation of SSC and SC was less than that of OC. The stress–strain curves' ascending branches of the three types were roughly similar; for the descending branch, the slope of SSC and SC became steeper compared with OC after carbonation. The results also revealed that the brittleness of SSC and SC increased orderly with the extension of carbonation time. Finally, an empirical expression for the stress–strain relationship of SSC and SC considering the effect of carbonation was proposed, which provides an analytical base for concrete structure design and practical application for marine infrastructures. [ABSTRACT FROM AUTHOR]

This work demonstrates an approach towards the understanding of multi-scale and open-circuit localised electrochemical processes of AA2024-T3 in the presence and absence of an environmentally friendly rare-earth inhibitor; cerium diphenyl phosphate (Ce(dpp)3). At high temporal resolution, a wire bean electrode (WBE) made from 100 identical AA2024-T3 wires revealed sudden increases in galvanic anodic and cathodic activities immediately after dosing of 50 and 100 ppm of the inhibitor and an overall suppression of macro-scale activities by increasing the inhibitor concentration to 200 ppm, suggesting it as a fast-screening tool for inhibitors and measuring inhibition efficiency. At high spatial resolutions, scanning probe electrochemical techniques confirmed local activation of corroding microstructures on individual AA2024-T3 wires similarly by dosing the inhibitor up to 100 ppm. In agreement with WBE findings, the effective shutdown of both anodic and cathodic activities occurred after increasing the inhibitor concentration to 200 ppm confirming the optimal concentration of the Ce(dpp)3 and the mixed mode inhibition mechanism of this selected inhibitor on AA2024-T3. [ABSTRACT FROM AUTHOR]

The effectiveness of a corrosion repair technique consisting of laser cleaning and cold spraying was investigated. The effect of laser pulse frequency on the removal of surface corrosion on steel specimens was analyzed. Subsequently, a zinc coating was cold-sprayed on specimens cleaned of surface corrosion using conventional disc grinder and laser methods. Furthermore, salt spray tests were conducted to compare the corrosion protection performance of the zinc coating on these specimens. The results showed that laser cleaning can effectively remove surface corrosion and that a laser pulse frequency of 15 kHz is more effective than that of 40 kHz for removing the surface oxide layer. A comparison of cold-sprayed zinc coatings on laser-cleaned and non-treated specimens indicated that surface oxidation during laser treatment may negatively affect zinc deposition efficiency. The zinc coating on the laser-cleaned specimen was more than twice as thick as that on the conventionally cleaned specimen, and the coating--specimen interface maintained good adhesion after a 168 h salt spray test. Although no corrosion was observed in both steel specimens after the salt spray test, cracking of the remaining corroded areas on the substrate and delamination of the coating occurred in the conventionally cleaned specimen. [ABSTRACT FROM AUTHOR]

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