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Tungsten carbides are important materials used in ceramic cements, machining tools, catalysts, sensors, and for hydrogen generation. Bulk W–C structures are highly complex; fundamental fully carburized WC and semi-carburized W 2 C are accompanied by structural transitions depending on the composition and temperature. The relationship between the structures, compositions, and temperatures is summarized in the W–C phase diagram. However, the high-temperature, stable, and single-crystalline nanoparticles related to the WC 1-x and W 2 C phases formed via energetic reactions accompanied by rapid cooling rates are not easy to determine considering the bulk phase diagram, and lead to fundamental questions regarding the origin of the nanophases. In this study, we propose a draft for the W–C nanophase diagram composed of the surface and gas-phase WC, WC 1-x , and W 2 C nanophases according to the composition and temperature. The model undergoes the process of a vapor–nanoliquid–nanophase starting from the gas-phase nucleation induced by an extremely high-temperature electrical explosion. In addition, the high-temperature reactivity and quenched nanophase, including its unique nanostructure, are related to the post-melt rheology, physical morphology, and steric hindrance of the solid matrix during an electrical explosion. [ABSTRACT FROM AUTHOR]

The API K55 grade steel is widely utilized in seamless pipes for oil and gas exploration, especially as casing pipes for wellbores. Traditionally, this steel is processed using hot rolling followed by quenching and tempering to achieve the desired dimensional and microstructural characteristics, balancing high strength with ductility. This article introduces an alternative method to attaining the required tensile properties for API K55 grade steel by employing a biphasic microstructure (ferrite/martensite) achieved through quenching post‐intercritical austenitizing heat treatment to high‐strength‐low‐alloy steel. Thermodynamic simulations and dilatometric experiments revealed that increasing the austenitizing temperature enhances austenite formation, decreasing significantly its carbon content, which facilitates martensitic transformation and increases the Ms and Mf temperatures. A complete phase transformation mapping was presented, highlighting how the austenitizing temperature influences martensitic transformation kinetics during the quenching heat treatment. It was concluded that austenitizing at 750 °C, followed by quenching and short tempering at 650 °C, produced a biphasic microstructure with 30% ferrite and 70% martensite, providing a favorable balance between mechanical strength and ductility that meets the API K55 grade requirements, surpassing traditional methods in the industry. [ABSTRACT FROM AUTHOR]

When a suitable balance of hardness, strength, and toughness is required in civil engineering and construction, wear-resistant medium carbon steels are frequently utilized. The ability to resist plastic deformation brought on by stress or abrasion is measured by hardness. High hardness materials are typically more brittle and prone to fracture but also stronger and more resistant to corrosion. A double-quenching procedure was used in the current investigation and contrasted with the traditional single-quenching process. Additionally, a variety of cooling media are used during quenching treatments. The results demonstrate that distilled water is the most effective cooling medium to cool the models in the heat treatment of medium carbon steels because it is free of salts, suspended particles, and metal contaminants. The results show that the hardness increased following the first quenching and tempering by 37.5% above the hardness value predicted by the original model, and it increased once more following the second quenching and tempering by 10% over the hardness value following the first heat-treatment. The previous austenite grain limits and the high-angle beam limits are the main factors that give a share in to the increased hardness, and the main elements that affect how effectively they function are the high slip transmission factor and the high spacing angle between slip levels. [ABSTRACT FROM AUTHOR]

In this paper, enhancing the tribological characteristics of novel cast metallic materials—hybrid multi-component cast irons—by applying a strengthening heat treatment is described. The experimental materials were the cast alloys of a nominal composition (5 wt.% W, 5 wt.% Mo, 5 wt.% V, 10 wt.% Cr, 2.5 wt.% Ti, Fe is a balance) supplemented with 0.3–1.1 wt.% C and 1.5–2.5 wt.% B (total of nine alloys). The heat treatment was oil-quenching followed by 200 °C tempering. The quench temperature (QT) varied in the range of 900–1200 °C, with a step of 50 °C (with a 2-h holding at QT). The correlation of the QT with microstructure and properties was estimated using microstructure/worn surface characterization, differential scanning calorimetry, hardness measurement, and three-body-abrasive wear testing (using Al2O3 particles). The as-cast alloys had a multi-phase structure consisting of primary and/or eutectic borocarbide M2(B,C)5, carboborides M(C,B), M7(C,B)3, M3(C,B), and the matrix (ferrite, martensite, pearlite/bainite) in different combinations and volume fractions. Generally, the increase in the quenching temperature resulted in a gradual increase in hardness (maximally to 66–67 HRC) and a decrease in the wear rate in most alloys. This was due to the change in the phase-structure state of the alloys under quenching, namely, the secondary carboboride precipitation, and replacing ferrite and pearlite/bainite with martensite. The wear rate was found to be inversely proportional to bulk hardness. The maximum wear resistance was attributed to QT = 1150–1200 °C, when the wear rate of the alloys was lowered by three to six times as compared to the as-cast state. With the QT increase, the difference in the wear rate of the alloys decreased by three times. The highest abrasive resistance was attributed to the alloys with 1.1 wt.% C, which had a 2.36–3.20 times lower wear rate as compared with that of the reference alloy (13 wt.% Cr cast iron, hardness of 66 HRC). The effects of carbon and boron on hardness and wear behavior are analyzed using the regression models developed according to the factorial design procedure. The wear mechanisms are discussed based on worn surface characterization. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering (17264073) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The process of glass transition during the quenching in the domain with the cold wall has been numerically simulated. We have implemented the temperature-dependent form of the previously proposed theoretical model, which combined the heat transfer in the domain and the gauge theory of glass transition, assuming the presence of topologically stable distortions (disclinations) in the forming solid. The competition between crystallization (formation of polycrystalline structure) and the formation of the amorphous disordered phase has been shown. At the relatively slow cooling rates corresponding to the formation of the crystalline phase, we observed a columnar to equiaxed transition qualitatively similar to the observed in many metallic alloys. The moving front followed the equilibrium isotherm corresponding to the equilibrium temperature of transition in the disclinations subsystem, although front drag resulted in the effect of kinetic undercooling and the emergence of the maximum velocity of the crystallization front. High thermal conductivity values associated with the substantial heat flux lead to the bulk amorphous state. The dynamics of the coarsening of the primary amorphous structure depended on the annealing temperature. [ABSTRACT FROM AUTHOR]

A single-photon avalanche diode (SPAD) is a photon-counting sensor renowned for its exceptional single-photon sensitivity. One significant feature of SPADs is their non-linear response to light, making them ideal for high-dynamic range imaging applications. In SPAD imaging, the photon detection mode, which depends on the quenching method employed, is crucial for optimizing image quality and dynamic range. This paper examines the free-running and gating imaging modes, evaluating their impacts on photon capture and saturation limits. Given that the number of incident photons follows a Poisson distribution, we introduce an innovative imaging-quenching model based on statistical mathematics. We designed and fabricated two SPAD imaging sensors using 180 nm CMOS technology. Image processing and evaluation were conducted using a mapping method. Our results show that in low-light conditions, the gating mode surpasses the free-running mode in the signal-to-noise ratio (SNR). However, the free-running mode exhibits a saturation limit of more than an order of magnitude higher than that of the gating mode, demonstrating its superior capability to handle a broader range of light intensities. This paper provides a thorough analysis of the differences between the two imaging methods, incorporating the theoretical mathematical model, circuit characteristics, and computed imaging quality. [ABSTRACT FROM AUTHOR]

Copyright of Bearing is the property of Bearing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The low-carbon steel revealed the presence of ferrite-pearlite and ferrite-martensite microstructures after being subjected to different thermomechanical routes. These routes involved two distinct stages: 1) reheating hot-rolled steel at 1473 K, followed by cooling via step quenching, intermediate quenching, and furnace cooling, and 2) cold rolling and subsequently annealing at 873 K for 2 and 8 h. The quenching schedules finally developed a ferrite-martensite structure with different martensitic morphology, whereas furnace cooling promotes a ferrite-pearlite structure. The prolonged annealing assists in carbide precipitation from deformed ferrite-martensite microstructure while pre-existing carbides coarsen after 8 h of annealing in furnace-cooled specimens. The sudden phase disintegration contributes to the changes in the recrystallized kinetics and evolution of precipitates, tailoring the final grain size. Additionally, the development of textures after cold rolling and annealing is studied through the emergence of α and γ fiber in BCC phase. Finally, detailed microscopic technique has been employed to correlate the overall tensile response of the investigated samples with their interrelated microstructures. [ABSTRACT FROM AUTHOR]

This paper addresses the combustion of ammonium perchlorate (AP) near adiabatic conditions at high pressures and higher initial temperatures. The AP pellets were coated with a thin layer of silica grease to simulate the near adiabatic condition. The experiments were performed at initial temperatures of 30 and 70 °C in the pressure range of 2.5–30 MPa for coated and bare pellets. The bare pellets were found to exhibit mesa burning as reported in the literature. However, the coated pellets did not exhibit mesa burning. The burn rates of coated AP pellets increased linearly for the entire pressure range of 2.5–30 MPa with 0.64 pressure index. Further, the experiments were carried out for the first time at an initial temperature of 90 °C for 14–30 MPa pressure range, wherein, AP combustion did not display any characteristics of mesa burning (pressure index of 0.33). The surface morphology of quenched samples of both bare and coated pellets of AP were studied, by quenching (rapid depressurization technique) pellets at 6, 12, and 18 MPa pressures. The surface structure of quenched samples for near adiabatic conditions was similar for all three pressures. However, for bare pellets the changes in surface structure were observed with change in pressure, similar to the literature. Mesa burning was found to be an effect of convective heat loss from the periphery of the pellets and it was not observed when heat loss was reduced or initial temperature was higher than the critical initial temperature. [ABSTRACT FROM AUTHOR]

Self‐healing materials that integrate excellent mechanical properties and high healing efficiency meet the requirements of flexible electronic sensors for mechanical flexibility and reliability. In the field of wearable devices, they are of great significance for improving the stability of the equipment and reducing the frequency of replacement. However, the high strength of materials often limits their self‐healing ability. When damage occurs, it will hinder the microstructural adjustment and fluidity of the material at the damaged site, thus negatively affecting the activation and execution of the self‐healing mechanism. In this study, a strength‐toughness and room‐temperature self‐healing triboelectric material is prepared by the dynamic nanoconfinement effect and the quenching effect of ethanol (referred to as the DNCQ strategy). The quenching effect of ethanol improves the aggregation of nanocluster phase, and the constructed nanoconfined network skillfully balances the contradiction between mechanical properties and self‐healing ability. The obtained triboelectric material has high tensile strength (27.1 MPa), toughness (97.9 MJ m−3), and excellent healing efficiency (88.6%). The self‐powered pressure distribution sensing array based on triboelectric materials can accurately reflect the pressure distribution of the object, which has potential application prospects in the field of wearable devices. [ABSTRACT FROM AUTHOR]

CsPbX 3 (X = Cl/Br, Br, Br/I, I) perovskite quantum dots (QDs) glasses have enormous application potential in the field of long wavelength pass (short wavelength cutoff) filters. In this work, the CsPbX 3 (X = Cl/Br, Br, Br/I, I) QDs doped with Se4+ were prepared in the borogermanate glass matrix. To quench strong exciton emission of QDs, the CsPbX 3 (X = Cl/Br, Br, Br/I, I) perovskite QDs glasses were doped with Se4+ at different concentrations of 0, 0.05 %, 0.1 % and 0.2 %, respectively. The nanocrystal structure, transmittance, optical density, photoluminescence (PL), PL excitation and PL decay have been investigated. The working wavelength of filters has been extended to wide range from 440 nm to 650 nm. The samples have large optical density in cutoff region, excellent steepness in the transition region, and high transmittance in transmission region. As Se4+ concentration increases, the PL intensity is quenched and the PL lifetime is decreased obviously for CsPbX 3 QDs glasses, whereas the absorption and transmittance characteristics for filters are less affected. The quenching mechanism is attributed to nonradiative recombination by deep energy level traps. The Se4+ doped CsPbX 3 QDs glasses can meet requirements for the long wavelength pass filters. [ABSTRACT FROM AUTHOR]

The process of transition from the liquid to the solid state during the uniform quenching is described by a combination of two theoretical approaches: the phase field method and the gauge theory, which suggests the phase transition in the subsystem of topologically stable distortions. Using the stochastic partial differential equations we numerically simulate competition between the processes of crystallization and vitrification during the rapid cooling of the melt. A glass order parameter which is suitable for the characterization of transition to the glassy state has been proposed. At low cooling rates, the domain freezes into the crystalline structure with defects, and its glass order parameter is orders of magnitude less than that for the vitrified state obtained by rapid quenching. Proposed method improves and extends the theoretical description of glass transition, qualitatively represents the basic kinetic properties of the process and demonstrates sensitivity of resulting microstructures to the quenching rate. [ABSTRACT FROM AUTHOR]

Initially, a brief historical review related to the discovery of iron is made. Studies of artifacts such as tools blades and weapons from more than 1000 years BC, allowed us to conclude that the knowledge already existed to increase the hardness of metals, both due to the increase in carbon content and sudden cooling from high temperatures (a process called tempering or hardening). This suggests that there was a considerable degree of sophistication on the part of these early blacksmiths. Next, the basics of materials theory and formation of the crystalline structure of iron- carbide iron (Fe-Fe3C) based on the phase diagram are presented. Modernly, materials science has shown that increasing temperature changes the atomic structure of ferrite (pure iron with BCC structure) to austenite (FCC), which allows the inclusion of other elements, such as carbon, for example. The quenching process, on the other hand, abruptly changes the atomic structure from austenite to martensite (BCT), keeping the carbon attached to the final structure, giving the new material a significant increase in hardness. Although the context of the article is, at first glance, historical, the controlled heat treatment of steel is essential for the modern world and is used to ensure that it has the desired properties in industry in general. [ABSTRACT FROM AUTHOR]

Sodium bismuth titanate‐based materials are expected to be an alternative candidate to lead‐based ceramic materials due to their excellent electrical properties. However, the low depolarization temperature (Td) limits their practical application. In this work, the phase structure evolution and microstructure of 0.9(0.4Na1/2Bi1/2TiO3–0.6BiFeO3)–0.1BaTiO3: xZnO (x = 0.01, 0.03, 0.05, and 0.07) (abbreviated as 100xZnO) composite ceramics are investigated, and their piezoelectric properties are improved by combination of constructing 0–3 type composites and quenching treatment technology. The addition of ZnO can increase both Td and d33 because ZnO can enhance the lattice distortion of rhombohedral phase and lead to the increase in ferroelectric order. Specifically, the optimum composition x = 0.03 obtains the d33 value of 106 pC/N (25°C), which retains 84% of the value at room temperature up to 240°C. And the quenching technology further enhances the ferroelectric order and increases Td, which is up to 280°C for x = 0.03. [ABSTRACT FROM AUTHOR]

Solid solution strengthened ferritic ductile iron proves to have a better ratio of tensile strength to elongation than conventional ductile iron grades. This applies up to a maximum silicon content of 4.3 wt%, beyond which it leads to an abrupt decrease in ultimate tensile strength and elongation at fracture. During solidification of high silicon ductile iron, negative segregation of silicon occurs, and the highest silicon concentration is observed near the graphite nodules. This high silicon concentration leads to long-range ordering of iron and silicon, and this ordering results in formation of superstructures like BCC_B2 and D03. The presence of super structures restricts the mobility of dislocations and leads to abrupt fracture of the material. This research focuses on the investigation of silicon homogenization by the addition of aluminium and heat treatments to avoid the formation of brittle iron–silicon superstructure. Thermodynamic–kinetic simulations as well as experimental investigations, including variation in alloy composition and quenching, are performed. The results provide a promising understanding to control the micro-segregation of silicon in ductile cast iron based on heat treatments and alloy composition. [ABSTRACT FROM AUTHOR]

Biochar is one of the most important carbon-rich minerals with a porous structure in the carbon sequestration, immobilization of metal and organic contaminants, as well as soil fertility improvement. However, its large-scale use is very limited in the agriculture and environment, due to the high cost of production and transportation from agricultural biowaste to plant. In this study, a new technology was explored to directly convert from agricultural biowaste to biochar in the field. The local applications had significantly reduced the costs of biochar. Inspired by nature, biochar production was also proposed in the field, where only agricultural biowaste, water, and fire were required for biomass carbonization and charcoal formation; Specifically, Litchi branches sourced from subtropical regions were utilized as feedstock to explore an on-site production of biochar. Soil (Ferralsols) slurry was applied as a coating and quenching agent to create an oxygen-limited environment during fire-water coupled carbonization of the feedstock. This self-limiting oxidation approach was used to minimize the expenses of production, transportation, and utilization. Biochar that was produced with soil slurry coating and quenching also displayed the highest carbon content (83.5%) and carbon capture capacity (83.9%), exceeding unconverted biomass and biochar produced without coating by 16.7% and 37.8%, respectively. The burning process of Litchi branches was divided into three stages: 1) Surface was charred immediately but with an unburned core; 2) Surface was grayed out, while the core was in a self-ignition state with high temperature and limited oxygen, and the dark red char fell to the ground; and 3) The dark red char gradually burned out to be ash. Spraying water on the dark red char was used to prevent the occurrence of the 3rd stage, thus favoring the formation of biochar instead of ash. Furthermore, the soil coating likely acted as a barrier, thus reducing carbon monoxide or carbon dioxide release during combustion. Additionally, the soil integration was facilitated to form the mineral-carbon composite for the carbon capture. Scanning electron microscopy and energy spectroscopy analysis show that the regular structure of the carbon skeleton was observed after coating and quenching the iron-aluminum slurry. The iron-aluminum minerals were also loaded on the surface. A novel approach to carbonization accelerated a paradigm shift in biochar production from a sophisticated stationary facility to a simple way for practical use in the field. Low cost greatly contributed to the agricultural and environmental application of biochar. The economically viable combination of fire and soil (Ferralsols) slurry coupled carbonization can be expected to provide valuable insights for biochar adoption and carbon neutrality. In conclusion, the readily available agricultural residues and soil-based coatings can be integrated to mitigate the environmental impact of biochar production, in order to enhance the efficacy as a carbon capture. These findings can offer significant implications for the broader adoption of biochar as a sustainable solution, in order to promote climate and soil health. [ABSTRACT FROM AUTHOR]

In this study, an environmentally sustainable fluorimetric method for determination of Vonoprazan fumarate (VON) in dosage forms using nanoprobes consisting of nitrogen and sulfur co‐doped carbon quantum dots (N, S‐CQDs). The N, S‐CQDs were prepared through a microwave‐assisted method in 30 s. The resulting N, S‐CQDs were characterized using transmission electron microscopy (TEM), high‐resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), and X‐ray photoelectron spectroscopy (XPS). They exhibit fluorescence emission at 460 nm after excitation at 385 nm with a high quantum yield (60%). The analytical approach for VON determination relies on the quenching effect exerted by VON on the native fluorescence intensity of CQDs. The quenching mechanism was investigated using Stern–Volmer plots. The proposed method demonstrates linearity across a concentration range 10–80 μM (4.6–36.8 μg/mL) with corresponding limits of detection and quantitation calculated as 2.17 μM (0.99 μg/mL) and 6.58 μM (3.02 μg/mL), respectively. The method has been effectively utilized for the determination of VON in the pharmaceutical samples. Statistical comparison with reported RP‐HPLC has been performed to verify the accuracy and precision of the developed method. The environmental sustainability of the developed method has been thoroughly examined through various greenness metrics. [ABSTRACT FROM AUTHOR]

Mefenamic acid, renowned for its analgesic properties, stands as a reliable choice for alleviating mild to moderate pain. However, its versatility extends beyond pain relief, with ongoing research unveiling its promising therapeutic potential across diverse domains. A straightforward, environmentally friendly, and sensitive spectrofluorometric technique has been developed for the precise quantification of the analgesic medication, mefenamic acid. This method relies on the immediate reduction of fluorescence emitted by a probe upon interaction with varying concentrations of the drug. The fluorescent probe utilized, N‐phenyl‐1‐naphthylamine (NPNA), was synthesized in a single step, and the fluorescence intensities were measured at 480 nm using synchronous fluorescence spectroscopy with a wavelength difference of 200 nm. Temperature variations and lifetime studies indicated that the quenching process was static. The calibration curve exhibited linearity within the concentration range of 0.50–9.00 μg/mL, with a detection limit of 60.00 ng/mL. Various experimental parameters affecting the quenching process were meticulously examined and optimized. The proposed technique was successfully applied to determine mefenamic acid in pharmaceutical formulations, plasma, and urine, yielding excellent recoveries ranging from 98% to 100.5%. The greenness of the developed method was evaluated using three metrics: the Analytical Eco‐scale, AGREE, and the Green Analytical Procedure Index. [ABSTRACT FROM AUTHOR]

Copyright of Iron Steel Vanadium Titanium is the property of Iron Steel Vanadium Titanium Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effects of quenching and tempering temperatures on the microstructure and mechanical properties of super martensitic stainless steel (SMSS) 00Cr13Ni5Mo were studied. The SMSS after heat treatment is composed of martensite (α phase) and a small amount of austenite. When the quenching temperature is 930 °C, with the increase of tempering temperature, the enrichment of Ni in martensite leads to the formation of reverse austenite, the content of martensite phase decreases from 84.9 % to 80.0 %, and the average grain size increases from 23.23 μm to 27.07 μm. When tempering at 580 °C, the content of martensite phase decreases from 80.0 % to 83.7 % with the increase of quenching temperature. The average grain size increased from 25.23 μm to 35.01 μm. When the quenching temperature is 930 °C, the hardness and yield strength of SMSS decrease, and the hardness and yield strength are the highest at 530 °C, which are 275 HV and 873 MPa. The plasticity increases first and then decreases, and the plasticity is the best at 580 °C. The elongation and reduction of area were 22.87% and 71.41%. These changes in mechanical properties are mainly related to the content of martensite and reversed austenite in the microstructure. The tensile strength and elongation of SMSS under different process conditions were compared. The results show that when the quenching temperature is 930 °C and the tempering temperature is 580 °C, the comprehensive performance of SMSS is the best, reaching 18700 MPa•%. This value is 31% higher than that of forgings. Finally, the formation mechanism of reversed austenite was discussed, and the strengthening model of SMSS 00Cr13Ni5Mo was established.

The process of glass transition during the quenching in the domain with the cold wall has been numerically simulated. We have implemented the temperature-dependent form of the previously proposed theoretical model, which combined the heat transfer in the domain and the gauge theory of glass transition, assuming the presence of topologically stable distortions (disclinations) in the forming solid. The competition between crystallization (formation of polycrystalline structure) and the formation of the amorphous disordered phase has been shown. At the relatively slow cooling rates corresponding to the formation of the crystalline phase, we observed a columnar to equiaxed transition qualitatively similar to the observed in many metallic alloys. The moving front followed the equilibrium isotherm corresponding to the equilibrium temperature of transition in the disclinations subsystem, although front drag resulted in the effect of kinetic undercooling and the emergence of the maximum velocity of the crystallization front. High thermal conductivity values associated with the substantial heat flux lead to the bulk amorphous state. The dynamics of the coarsening of the primary amorphous structure depended on the annealing temperature.

AbstractAcute respiratory distress syndrome (ARDS) is a complication of pulmonary disease that produces life-threatening hypoxaemia. Despite ventilation and hyperoxic therapies, undetected hypoxia can manifest in capillary beds leading to multi-organ failure. Ox66™ is an ingestible, solid-state form of oxygen designed to supplement oxygen deficits. Twenty-four anaesthetized rats underwent a two-hit model of respiratory distress (ARDS), where a single dose (5 mg/kg) of lipopolysaccharide (LPS) was given intratracheally, and then the respiratory tidal volume was reduced by 40%. After 60 min, animals were randomized to receive Ox66™, or normal saline (NS; vehicle control) via gavage or supplemental inspired oxygen (40% FiO2). A second gavage was administered at 120 min. Cardiovascular function and blood oximetry/chemistry were measured alongside the peripheral spinotrapezius muscle’s interstitial oxygenation (PISFO2). ARDS reduced mean arterial pressure (MAP) and PISFO2 compared to baseline (BL) for all treatment groups. Treatment with Ox66 or NS did not improve MAP, but 40% FiO2 caused a rapid return to BL. PISFO2 improved after treatment with Ox66™ and 40% FiO2 and remained elevated for both groups against NS until study conclusion. Both oxygen treatments also suppressed the inflammatory response to LPS, suggesting that Ox66™ can deliver therapeutically-impactful levels of oxygen in situations of pulmonary dysfunction.

In this paper, we addressed a coupled electromagnetic and thermal field problem in an induction heating process. The paper presents the results obtained through numerical simulation of the electromagnetic field coupled with the thermal field in electromagnetic induction heating systems. The modeling results largely depend on the accuracy of the material properties data and their variation with temperature.

AISI 1045, Medium-carbon steel is commonly used as machining components like bulldozer bushings and widely used in construction equipment such as hammerheads. Hence, it needs good hardness and impact resistance. The methods to achieve these properties are through a heat treatment process called quenching and tempering. This research analyzed the effects of various austenitizing holding times during the quenching and tempering process on the microstructure, hardness, and impact strength of AISI 1045 steel. The procedure involved quenching the steel at a temperature of 850°C with austenitizing holding times of 5, 15, and 25 minutes, followed by rapid cooling using ice water. Subsequently, tempering was performed at 500°C with a holding time of 15 minutes, followed by air cooling. The research showed that all three test specimens exhibited bainite and martensite phases. The hardness of the steel increased after undergoing the quenching and tempering process, with the highest hardness value obtained at a 5-minute austenitizing holding time, measuring 32.37 HRC. Additionally, there was an increase in impact strength after the quenching and tempering process. Tobe found the highest impact strength value observed at with a 25-minute austenitizing holding time at 27.39 J/cm².

The new ligand 3,3′‐bis(((2‐(3,6,9‐triaza‐1(2,6)‐pyridinacyclodecaphane‐6‐yl)ethyl)amino)methyl)‐[1,1′‐biphenyl]‐2,2′‐diol (L) has been synthesized and characterized. It contains two pyridinacyclophane macrocycles spaced by a 2,2’‐biphenol moiety. The acid‐base behaviour of L as well as its binding properties towards Zn2+ ion have been investigated. This work is inserted in the field of fluorescent ditopic receptors, formed by two polyamines spaced by a aromatic fragments. This ligand represents a new example of a peculiar case of polyamine fluorescent receptor in which the interaction with Zn2+ is translated into a deactivation of the emission. Enough data to describe and explain this unusual behaviour was obtained through potentiometric, UV‐Vis, fluorescence and NMR titrations as well as theoretical calculations. This studies have shown that the metal cation is indirectly affecting the emission favouring a conformation in which the fluorophore is at stacking distance from the electron poor pyridine moieties. This gives rise to an oxidative photoinduced electron transfer from the excited state of the fluorophore to the electron‐poor Zn2+ coordined pyridine. [ABSTRACT FROM AUTHOR]

Geometric distortion is a common occurrence in the manufacturing of fragile structures, especially in thin-walled parts. Current numerical prediction approaches in determining the extent of distortion are limited by the availability of extensive test data and the absence of specific identification of driving factor/s for distortion. To address the issue, this study proposes an innovative method to develop the hypothesis for identifying the critical contributing factors for distortion and a novel finite element based framework is developed for validating the hypothesis. The framework is implemented on a experimental non-prismatic industrial part and the results support the proposition that quenching is the most significant contributor to distortion in thin-walled parts made from Haynes 282 alloy. The framework/model provides valuable insights into the significant contributions of quenching induced thermal gradients and the material state towards part distortion. It is adaptable for predicting distortion in thin-walled geometries made of Haynes 282, overcoming the limitations of current numerical prediction methods. [ABSTRACT FROM AUTHOR]

To achieve the necessary mechanical properties and high corrosion resistance, heat treatment is based on a significant alteration in the microstructure of metals and alloys. The metal is heated above a critical temperature during heat treatment processes. Several methods, such as quenching and cooling in various media, followed by tempering and other heat treatment operations, can be used to achieve this. Steel can be made more malleable by annealing, which also increases ductility and improves corrosion resistance. In this study, thirty medium carbon steel specimens were used, which were split into different groups, various heat treatments were applied. First quenching, first tempering, second quenching, and second tempering were among the heat treatment procedures used, and cooling media made of distilled water were used at various temperatures. After that, the corrosion rate in these specimens was looked at, and the results were compared to the corrosion rate in the base specimen. The results show that repeated heat treatment of the metal generally lowers the rate of corrosion in the metal, particularly when distilled water is used for the cooling process after the two tempering stages at a temperature of almost absolute zero. The findings show that the second sample had the lowest corrosion rate of all the samples. When compared to the corrosion rate in the basic sample, the corrosion rate in this sample decreased by about 92.9%. [ABSTRACT FROM AUTHOR]

In this paper, we study the quenching phenomenon related to the ω-diffusion equation on graphs with a potential and a singular source ut(x, t) = Δωu(x, t) + b(x)(1 - u(x, t))-p, where Δω is called the discrete weighted Laplacian operator. Under some appropriate hypotheses, we prove the existence and uniqueness of the local solution via Banach fixed point theorem. We also show that the solution of the problem quenches in a finite time and that the time-derivative blows up at the quenching time. Moreover, we estimate the quenching time and the quenching rate. Finally, we verify our results through some numerical examples. [ABSTRACT FROM AUTHOR]

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The influence of additives on the decomposition and combustion characteristics of electrically controlled solid propellants was investigated through small scale experiments. Carbon black and aluminum additives were explored in a polyethylene oxide, lithium perchlorate propellant. Additives were used to improve the voltage response and their impact on ignition and combustion was characterized. The data showed that conductive additives can mitigate the loss of solid phase conductivity through solvent evaporation and that ignition delay decreases with higher voltage and solid phase conductivity. Steady‐state combustion experiments showed that electrical decomposition of the propellants proceeded more rapidly than a purely thermal stimulus illustrating the importance of electrochemistry in ECSP combustion. The combined effects of pressure and voltage on combustion rates were summarized in Saint‐Robert's burn relations. The regression rates increased with both applied voltage and pressure. The pressure deflagration limit of propellants with the carbon black additive was significantly reduced compared to a neat PEO/LP propellant, whereas the addition of 10 % aluminum did not affect the pressure deflagration limit. [ABSTRACT FROM AUTHOR]

The existence of warfarin is beneficial for health, but its increase in the human body causes toxicity and increases the risk of bleeding. This research focuses on introducing a facile and safe fluorescence sensor for warfarin detection in biological samples. The synthesis of the fluorescence sensor probe was easily performed with doping metal ions of the Pt to CdTe quantum dots. The morphological and optical properties of the synthesized Pt:CdTe quantum dots were characterized by FT-IR, TEM, and EDX. The interaction patterns of warfarin with CdTe QDs were investigated by the quantum chemical method and compared with experimental results. The proposed quantum dots exhibited a blue luminescence with a 28.8% quantum yield. Pt:CdTe QDs were used as the fluorescence probe to assay warfarin. This procedure is based on the "off" fluorescence of quantum dots in the presence of different concentrations of warfarin. Under optimal conditions, the fluorescence sensor probe could detect the concentration of warfarin with a wide linear range of 0.1–100 μM and a detection limit (S/N = 3) of 0.05 µM. Results of sample analysis by fluorescent nanoprobe displayed that this probe could be the potential alternative tool for warfarin detection in biological samples. [ABSTRACT FROM AUTHOR]

A novel flameless operating mode is introduced, which improves the response of a multiple flame photometric detector (mFPD). The mFPD normally has analyte travel through 4 'worker' flames in series before entering a final 'analytical' flame where its emission is monitored. Here, it is found that when the analytical flame is not ignited, background luminescence is reduced over 30 times and the strong analyte chemiluminescence of the worker flames can be made to extend a large distance (~ 10 flame widths) into the analytical flame region where it is detected. This occurs for phosphorous (HPO*), quadratic sulfur (S2*), and linear sulfur (HSO*) emission. Conversely, carbon emission resides inside the worker flames and yields a small negative signal. As a result, very good selectivity over carbon is observed, and improved minimum detectable limits (MDL) of 4 pg S/s (S2*) and 0.3 pg P/s (HPO*) are obtained, which are up to 20 times lower than previous values reported for the mFPD. Further, linear sulfur (HSO*) yields an MDL of 6 pg S/s, which is over 3 times lower than values reported for other FPDs. Due to the worker flames present in this mode, other benefits of regular mFPD operation are maintained, like uniform analyte response and large quenching resistance. In application, a trace benzothiophene analyte is readily detected within a concentrated diesel fuel matrix in the flameless mFPD mode, while no response is observed in the conventional FPD mode. Results indicate that this flameless operating mode is advantageous for sulfur and phosphorous analysis. [ABSTRACT FROM AUTHOR]

The emission of highly polarized light by organic light‐emitting diodes (OLEDs) is crucial for various applications; however, achieving such emission requires the use of polarizers, which reduce the device efficiency and durability. In this study, ultrahigh‐polarized light with a polarization ratio (PR) of 407:1 is achieved via the rapid thermal quenching (RTQ) of OLEDs. Poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) films, molybdenum disulfide (MoS2) nanosheets, and tungsten disulfide (WS2) nanosheets are applied as hole transport layers and surface‐alignment layers through surface treatment, including rubbing and/or ion‐beam exposure to align the molecules of the emissive materials, namely, {poly(9,9‐dioctylfluorene‐alt‐benzothiadiazole) (F8BT). Quenching is performed at 240 °C, at which F8BT has a nematic liquid crystal (NLC) phase with high molecular ordering. Upon quenching, the high molecular ordering of the NLC‐phased emissive layer instantaneously froze via RTQ, leading to the emission of highly polarized light. Consequently, the PEDOT:PSS‐, MoS2‐, and WS2‐based OLEDs exhibit ultrahigh PRs of 407:1, 349:1, and 328:1, respectively, for photoluminescence at a 540 nm peak wavelength. In contrast, for electroluminescence, the PEDOT:PSS‐based OLED exhibits a high PR of 395:1. This result is the best reported to date and is comparable to the PRs generated by polarizers, indicating that quenching can be utilized for the development of ultrahigh‐polarized light‐emitting devices. [ABSTRACT FROM AUTHOR]

Borophene is a relatively unexplored two-dimensional (2D) layered material known for its high carrier mobility and robustness. Being the lightest 2D layered material, borophene quantum dots (BQDs) with small lateral dimensions have triggered a surge of interest in the material research community due to their distinct electronic and optical properties. In this work, we have carried out a contamination-free liquid-phase exfoliation of crystalline boron chunks to synthesize ultrasmall crystalline BQDs of sizes ∼4.1 and ∼9.2 nm. The BQDs are few-layered in nature, as confirmed by atomic force microscopy. The as-synthesized BQDs exhibit extraordinary visible photoluminescence (PL) with a high PL quantum yield (∼40%), and the emission wavelength is independent of the excitation wavelength, unlike many other 2D quantum dots. The PL spectrum could be deconvoluted with four peaks, which are marginally size-dependent. The selective coordination of different metal ions (Fe3+, Cu2+, Ag+, Zn2+, K+, Pb2+, Mg2+, Na+, Ni2+, Hg2+, Mn2+, Ce4+, and Fe2+) with the BQDs has been studied systematically through PL and density functional theory (DFT) analyses. Interestingly, the BQDs show a high PL quenching ratio (>90%) and ultralow limit of detection (∼5 nM) through PL in the presence of Fe3+ ions. The proposed sensor is successfully implemented, for the first time, for the sensitive detection of Fe3+ ions at the nanomolar level, and the sensing mechanism, including selectivity, is explored in detail using DFT calculation and phenomenological modeling of the experimental data to account for the sensing quantitatively over a wide dynamic range. Our results indicate that BQDs hold great potential for developing highly sensitive gas, molecular, bio-, and optoelectronic sensors in the future. [ABSTRACT FROM AUTHOR]

Defect-free thin-walled samples were built using wire arc additive manufacturing (WAAM) combined with the "coldArc" deposition technique by feeding a Ti-6Al-4V welding wire and using two deposition strategies, namely with and without the welding torch weaving. The microstructures formed in these samples were examined in relation to mechanical characteristics. The arc torch weaving at 1 Hz allowed us to interfere with the epitaxial growth of the β-Ti columnar grains and, thus, obtain them a lower aspect ratio. Upon cooling, the α/α′+β structure was formed inside the former β-Ti grains, and this structure proved to be more uniform as compared to that of the samples built without the weaving. The subtransus quenching of the samples in water did not have any effect on the structure and properties of samples built with the arc torch weaving, whereas a more uniform grain structure was formed in the sample built without weaving. Quenching resulted also in a reduction in the relative elongation by 30% in both cases. [ABSTRACT FROM AUTHOR]

Bulk samples of Tris (8-hydroxyquinoline) aluminium (Alq3) were prepared using wet synthesis method followed by annealing at 50 °C, 100 °C, 150 °C and 200 °C for 2 h. X ray diffraction pattern showed the formation of Alq3 crystal which is constituted of Al atom, anions of 8-hydroxyquinoline (8-Hq) and porous Al2O3–Al(OH)3. structure. The spectra of FTIR (Fourier-transform infrared) reveals that annealing Alq3 at 50 °C reduces the C=C peak to negligible but reappears when annealed at 150 °C. FESEM on as-prepared Alq3 shows hexagonal rod shaped stacked structures which on annealing at 50 °C changes to tetragonal agglomerated grains along with appearance of oval and circular shaped pores on it. From fluorescence spectroscopy it is found that the peak intensity changes non-monotonically with annealing temperatures followed by red shift and blue shift of peak maximum at 150 °C and 200 °C respectively. The temperature dependent change in the properties are mainly attributed to the onset of hydrolysis in Alq3 and change in the electronic transition levels. [ABSTRACT FROM AUTHOR]

Interaction of neutral and charged lipophilic beta-blocker drug, propranolol (PPL) with biomimicking nanocavities formed by micelles bearing same and opposite charges namely, cationic cetyltrimethylammonium bromide (CTAB), a surface-active ionic liquid 1-hexadecyl-3-methylimidazolium chloride (HDMIC) and anionic sodium dodecyl sulphate (SDS) have been investigated using fluorescence and absorption spectroscopic techniques. Binding of PPL to SDS at pH < pKa is characterised by biphasic interactions with decrease in fluorescence intensity at lower concentrations and subsequent increase post micellization. All the surfactants show significant interactions with the neutral drug molecule at pH > pKa, which is evident from the strongest binding constant ( K b ) values at pH 10.4. Results of quenching studies indicate that the location of drug molecule is determined by its charge, which is influenced by both pH and charge on micelle surface. For PPL-CTAB and PPL-HDMIC systems, quenching was strongest at pH 10.4, moderate at pH 7.4 and was absent at pH 3.5. However, the PPL-SDS system displayed similar K SV values at all pH conditions, suggesting that the probe is at the same position regardless of pH. Non-covalent interactions, which play crucial role in biological systems, are similarly the primary driving force governing the interaction between PPL and surfactant micelles. [ABSTRACT FROM AUTHOR]

5,10,15,20-tetramethoxyphenylporphyrinatotin (IV) (SnTMPP) was synthesised. SnTMPP exhibited Soret band at 432 nm and emission peaks at 629 and 682 nm. The fluorescence intensity of SnTMPP was quenched in the presence of guanine linearly in the range 4 × 10–9 M to 7.2 × 10–8 M and the quenching response was found to be stable even in the presence of other nucleosides such as adenine, cytosine, uracil, thymine, alanine, aspartic acid and ascorbic acid. The detection limit was found to be 0.17 nM and the mechanism behind the decrease in the fluorescence intensity of SnTMPP in the presence of guanine is due to dynamic quenching, which was confirmed by cyclic voltammetric studies and life time studies. The CV studies illustrates the possibilty for an electron transfer between the guanine and the electron deficient metal core of SnTMPP. [ABSTRACT FROM AUTHOR]

The reuse of gutter oil has always been a sensitive social issue. In the heat treatment industry, engineers have also been troubled by the need to move away from dependence on petroleum derivatives for cleaner production. While vegetable oils appear to be a viable alternative, the higher cost and poor thermal and oxidative stability limit their use in the heat treatment industry. The use of gutter oil as a quenchant raw material not only makes the quenchant cost effective but also environmentally friendly. In this study, the cooling performance of fatty acid methyl ester prepared from gutter oil was evaluated and compared with soybean oil and mineral oil. Firstly, fatty acid methyl ester was obtained by esterification and transesterification of gutter oil to reduce the free fatty acid content and make it suitable for quenching and heat treatment. The experiments were carried out using an Inconel 600 standard probe according to ISO 9950. The cooling behavior of the quenching media was tested at oil bath temperatures of 40 °C, 60 °C, and 80 °C. Quenching was carried out using AISI 4340 to obtain Vickers microhardness distributions on cross-sections of heat-treated specimens and residual stresses were determined by x-ray diffraction for all test materials. The fatty acid methyl ester used for analysis produced a hardening depth equivalent to that of commercial mineral oil when quenching the AISI 4340 alloy steel. And the test results achieved cooling properties and quenching intensity comparable to mineral oil. This indicates that fatty acid methyl ester prepared from gutter oil has the potential to replace mineral oil. [ABSTRACT FROM AUTHOR]

Fluorescence imaging is an invaluable tool to investigate biomolecular dynamics, mechanics, and interactions in aqueous environments. Two‐dimensional materials offer large‐area, atomically smooth surfaces for wide‐field biomolecule imaging. Despite the success of graphene for on‐chip biosensing and biomolecule manipulation, its strong fluorescence‐quenching properties pose a challenge for biomolecular investigations that are based on direct optical readouts. Here, we employ few‐layer hexagonal boron nitride (hBN) as a precisely tailorable fluorescence spacer between labelled lipid membranes and graphene substrates. By stacking high‐quality hBN crystals in the 10–20 nm thickness range on monolayer graphene, we observe distance‐dependent fluorescence intensity variations. Remarkably, with hBN spacers as thin as 20 nm, the fluorescence intensity is comparable to bare SiO2/Si substrates, while the intensity was reduced to 60 % and 80 % with ~10 nm and ~16 nm hBN thicknesses respectively. We confirm that pre‐determined hBN thicknesses can be employed to control the non‐radiative energy transfer properties of graphene, with fluorescence quenching following a d−4 distance‐dependent behaviour. This seamless integration of electronically active and dielectric van der Waals materials into vertical heterostructures enables multifunctional platforms addressing the manipulation, localization, and visualization of biomolecules for fundamental biophysics and biosensing applications. [ABSTRACT FROM AUTHOR]