Equivalent Circle Diameter Research Articles

Numerical and experimental investigation on the operating characteristics of fan-shaped pulse detonation combustor

The internal flow channel of a turbine engine is typically annular. When circular pulse detonation combustors (PDCs) are installed in this channel, there is a problem with low section utilization rates. To solve this problem, a single-tube fan-shaped PDC test system was developed. The effects of ignition distance on the operating characteristics of the fan-shaped PDC using air and gasoline under different frequencies were studied through both experiment and 3-D numerical simulation. Numerical simulation was also used to investigate the formation and propagation characteristics of detonation waves. The results show that the fan-shaped PDC can operate stably at frequencies ranging from 5 to 25 Hz when the ignition distance is either 2.30 or 2.70 times the equivalent circle diameter from the thrust wall, and it is found to be better to ignite at a distance of 2.30 times the equivalent circle diameter. The blockage ratio of the lower arc surface is larger than that of the other surfaces. This results in more intense collision and reflection. A larger local high pressure area forms near the lower arc surface, which is conducive to the formation of detonation waves. However, the larger blockage ratio makes the flow loss larger, which weakens the intensity of the pressure waves near the lower arc surface. The detonation waves in the fan-shaped PDC travel closer to the upper arc surfaces.

In vitro comparison of the leakage of carbon dioxide and iodine contrast media in a bleeding model

BackgroundWe aimed to compare the hydrodynamic values of carbon dioxide (CO2) and iodine contrast media for bleeding detection using an in vitro model.Materials and methodsWe created a bleeding model with large and small wounds in simulated blood vessels. We connected a syringe to the bleeding model and the blood pressure transducer, filling the circuit with CO2 and iodine contrast media. The syringe’s piston was pressed, and the flow rate and intravascular pressure of the CO2 and iodine contrast media leaking from the bleeding model were measured. We compared each leaked contrast medium’s volume, sphere-equivalent diameter, and sphere-equivalent area. These values were analyzed to compare the visibility of the leakage objectively.ResultsAt a constant flow rate, the intravascular pressure required for the model to leak was lower for the CO2 than that for the iodine contrast medium. The CO2 contrast medium leakage volume, equivalent circle diameter, and equivalent circle area were greater than those of the iodine one. These values indicate higher CO2 visibility during fluoroscopy.ConclusionsIn the bleeding model, a CO2 contrast medium may be more prone to leakage than the iodine one in large and small wounds. Regarding visibility, a CO2 contrast medium may be more likely to detect leakage than an iodine one.

Metallographic Etching of Al–Mg–Zn–(Cu) Crossover Alloys

Various alloys demand customized etchants due to their diverse chemical compositions, particularly in the realm of aluminum alloys. Consequently, in this study, a technique is proposed for metallographic visualization of small grain structures within Al–Mg–Zn–(Cu) crossover alloys. In this method, a thermal pretreatment combined with an etching process is relied on. In the study, it is primarily sought to comprehend how grain‐boundary precipitation affects etchability, addressing the complexities of characterizing these alloys. The demonstrated approach facilitates the swift assessment of grain sizes <10 μm using light optical microscopy. Exploring the etchability of Al–Mg–Zn–(Cu) crossover alloys across a standard heat‐treatment pathway identifies the optimal treatment and suitable etchant for grain visualization. Through process refinement, a reduction in processing time is achieved by employing a single‐step preheat treatment lasting 20 min at 180 °C post solution annealing. Transmission electron microscope analysis reveals continuous occupancy of the grain boundary with T‐phase as the key factor influencing the alloy's etchability. Grain size assessment involves line intercept counting and equivalent circle diameter measurement for precise characterization.

Wear performance of FeCuMoTiV high entropy alloy coatings by laser cladding

FeCuMoTiV high-entropy alloy coatings were prepared on the surface of aluminum matrix composites using the laser cladding technique. The physical phase composition of the coating, the hardness of each physical phase, and the friction and wear behavior of the coating were studied in detail. The results show that: From the XRD and TEM analysis, the coating’s physical phases, BCC1(MoV) and BCC2(TiFe), are coherent. From the EBSD analysis, the grains of the coating have no obvious selective orientation, and the average equivalent circle diameter is 26.44 μm. Nanomechanical tests showed that the average hardness of the BCC1 phase in the coating was 7831.2 N mm−2, which provided the coating with excellent abrasion resistance. The average coefficient of friction of the coating showed a tendency to decrease and then increase with the increase of time, and it floated in the range of 0.3 ± 0.05. The coating forms a structure containing Fe2O3, MoO3, CuO, and TiO2 mixed oxide ‘glaze layer’ on the wear surface, which provides good lubrication. Combined with SEM analysis, the wear mechanism of the coating is a mixture of abrasive wear, oxidative wear, adhesive wear, and fatigue wear.

Characteristics of VE/HXLPE wear particle morphology: A comparative analysis with UHMWPE in an in vitro artificial tibial insert simulation test

Particle generation from artificial knee prostheses is a leading cause of artificial joint failures. Vitamin E stabilized highly cross-linked polyethylene (VE/HXLPE) is known for its antioxidant properties and minimal wear characteristics. However, research on the wear behavior of VE/HXLPE is limited. This study aims to compare wear debris from VE/HXLPE with the conventional material Ultra High Molecular Weight Polyethylene (UHMWPE) under identical in vitro test conditions. Specifically, Principal Component Analysis (PCA) was employed to morphologically categorize particles, resulting in four distinct groups for VE/HXLPE and five for UHMWPE. Notably, 68 % of VE/HXLPE particles exhibited small-sized spheroidal morphology, while UHMWPE mainly produced elongated bioactive particles. Key particle attributes were then assessed, including 'equivalent circle diameter (ECD)', 'aspect ratio (AR)', and 'roundness (R) ', and presented as frequency distributions. The morphological analysis revealed that VE/HXLPE particles displayed various shapes, such as spheroidal, flakes, bulks, rods, and fibrils, and their formation mechanism was discussed. Additionally, the Functional Biological Activity (FBA) of VE/HXLPE wear particles was calculated. The results demonstrated differences in particle sizes, shape distributions, and bioactivity between VE/HXLPE and UHMWPE, which indicates that VE/HXLPE particles had a lower likelihood of inducing osteolysis. This study holds promise for gaining deeper insights into the mechanical properties and the potential for bioactivity in VE/HXLPE as an artificial joint material.

Scanning electron microscopy analysis of non-metallic inclusions for making steels with superior mechanical properties

The objective of this novel research was to further understand the type, size and areal distribution of the non-metallic inclusions in bearing steels by applying state-of-the-art scanning electron microscopy (SEM) analysis in order to develop steels with superior properties. Ten samples were taken from bearing steel grade 52100 and analysed by SEM. It was concluded that SEM allows deeper understanding regarding the type, morphology, size, and distribution of the non-metallic inclusions by covering larger sample areas and accurate automatic energy dispersive X-ray microanalysis of the inclusions. While most of the non-metallic inclusions had an equivalent circle diameter (ECD) smaller than 20 µm, the main type of inclusions with ECDs larger than 20 µm were calcium aluminates. As the higher sulphur will tend to create sulphide type of inclusions and the lower sulphur will shift the inclusions towards calcium aluminate oxide types, it is recommended to keep the sulphur content at amounts above threshold that calcium aluminates appear.

CELLULOSE NANOCRYSTAL-INCORPORATED CO-PROCESSED EXCIPIENT IN TABLET FORMULATION

The objective of the current work is to develop a new co-processed excipient based on cellulose nanocrystals and investigate its pharmaceutical excipient properties. Cellulose nanocrystals were isolated from the pseudostem of Musa balbisiana, following TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy)-mediated oxidation, and then co-processed with potato starch by the wet granulation method. Physicochemical properties, including the flow property, consolidation characteristics and rate of consolidation, were investigated, and a Kawakita plot was also generated. The compressibility, compactibility and tabletability of the novel excipient were determined. The equivalent circle diameter of the excipient particle was calculated as 4.09±0.90 μm, exhibiting a fair to passable flow property. The mean yield pressure from the Heckel plot was found to be 82.64 MPa, indicating its ability to undergo plastic deformation at relatively lower compression pressures. When compared to sodium starch glycolate, a standard tablet disintegrant, the cellulose nanocrystal-based co-processed excipient produced better dissolution of the model drug paracetamol.

Laboratory investigation on the single particle crushing strength of carbonate gravel incorporating size and shape effects

Particle strength is one of the critical factors that causes the degradation of the mechanical behaviour of crushable soil. Because of the complexity of particle shape, its effect on particle strength has not been completely understood. In this study, single particle crushing tests were performed on carbonate gravel particles with three size fractions (i.e. 5–10 mm, 10–15 mm and 15–20 mm) and three shapes (i.e. blocky, rodlike and flaky), using a PartAn3D Maxi large particle size and shape analyser to obtain the shape characteristics of the particles. The determination of crushing strength for particles with complex shapes was discussed, and it was found that it is appropriate to use the area equivalent circle diameter to obtain the crushing strength. The influence of particle size and shape parameters, including the elongation index, flatness index, intercept sphericity, circularity and convexity, on the crushing strength were identified, and an index termed the form factor considering dimensions in three directions was proposed to describe the effect of particle shape. Based on this form factor, a probabilistic model was established to predict the distribution of crushing strength of carbonate gravel particles with various sizes and shapes. The proposed model could be used in the discrete-element method to consider the influence of shape in addition when evaluating particle breakage.

Deciphering the quantitative relationships between age-induced hierarchical microstructure characteristics and tensile properties of Ti20C alloy

Hierarchical microstructure (HM) shows excellent comprehensive properties, but the relationship between mechanical properties and HM characteristics is not clear. In this work, seven HMs of Ti20C were tailored by aging treatments, containing equiaxed α (αep), lamellar α of micron and submicron scale (αlp-i, αlp-ii) and transformed βt (with nano-scale precipitated phases ω/αs in β). Different combinations of strength and plasticity were achieved. It was found that, the different phase interfaces hindered dislocation transferring, and ω/αs phase restricted dislocation movements in βt, which resulted in strength improvement. Moreover, HM was quantitatively characterized, then the relationship between HM characteristics and yield strength (Rp0.2), elongation after fracture (A) was precisely deciphered by referring to Hall-Petch formula and mixing law. It was found that the influence of βt, αlp-ii, αep and αlp-i on Rp0.2 decreased orderly. The decrease in the thickness of αlp-ii and increase in the volume fraction (VF) of βt, αlp-ii, were the most effective methods to improve Rp0.2. For A, the VF of βt was negatively correlated with it, but the equivalent circle diameter (ECD) of αep and the thickness of αlp-i, αlp-ii were positively correlated with it. Specifically, αep and αlp-ii had a higher contribution to plasticity than αlp-i, and the increase in the ECD (or thickness) and VF of αep and αlp-ii was most beneficial to improve plasticity.

The dynamic recrystallization behavior of the Ti-5.5Mo-7.2Al-4.5Zr-2.6Sn-2.1Cr titanium alloy during hot rolling based on macro-meso multiscale crystal plasticity finite element approach

The understanding of dynamic recrystallization under complex thermo-mechanical coupling is still a technical challenge. Therefore, in this work, combining the Johnson-Mehl-Avrami-Kolmogorov recrystallization grain model, a macro-meso multiscale crystal plasticity finite element approach was innovatively proposed. The isothermal hot compression test was performed to obtain the true stress-strain curves of Ti-5.5Mo-7.2Al-4.5Zr-2.6Sn-2.1Cr titanium alloy (strain rates: 0.001 s−1, 0.01 s−1, 0.1 s−1, 1 s−1, and 10 s−1; temperatures: 650 ℃, 700 ℃, 750 ℃, 800 ℃, and 850 ℃). Afterward, corresponding fitted parameters can be used to update the volume fraction and size of recrystallized grains of each sub-step. The macro simulation results showed that the surface layer had prominent strain partitioning and lower equivalent stress after hot rolling (thickness reduction: 60 %). For the region of interest, the calculated volume fraction and equivalent circle diameter of recrystallized grains were 2.45% and ∼1 µm, respectively, which were in good agreement with the experimental results.

Investigation of the Quartz Distribution in Electro-Porcelain Materials

Analysis of the microstructure of electro-porcelain is important to better understand its influence on mechanical, electrical and aging behavior. The microstructures of two electro-porcelain materials with low and high quartz contents were analyzed with respect to the distribution of quartz. Using an adequate evaluation of EDS (energy dispersive spectroscopy) mapping data, a reproducible analysis of the size distribution and quantity of quartz was achieved. The method allows the analysis of large areas (12.5 mm2). Therefore, the probability of occurrence for a few large quartz grains could be determined. Independent of the overall amount of quartz in the materials, a wide distribution of the grain size was observed. The size of the large detected quartz grains in both materials was very similar. Around the large quartz particles, microcrack systems with lengths of several 100 µm were observed. They are linearly correlated with the equivalent circle diameter of the quartz grains. The evaluation of the cracks allowed us to determine the critical size below which no cracks around the quartz particles are formed. This size is approximately 10 µm.

Liquefaction Mitigation Analysis Using Vertical Drain

Liquefaction in semi-permeable soils such as fine sands occurs when the required time to transfer the pore water pressure into the form of effective stress is longer than the increased time of pore water pressure. Therefore, liquefaction mitigation needs to be done to speed up the air pressure flow time during an earthquake such as using vertical drains in this study. The data used here are adopted from previous studies that have been taken from a field test in Air Tawar, Padang. The results showed there is liquefaction potential based on soil data processing. The equivalent circle diameter value for the vertical drain is 1.2 m or a radial equivalent value of 0.6 m. Based on the analysis, the 60% pore water pressure dissipation within 20 seconds was obtained at a distance of 0.291 m in the radial direction. From the data above, it can be obtained that the vertical drain is capable of dissipating 60% of water pressure within 20 seconds to avoid liquefaction within the soil mass. Then it can be concluded that the application of vertical drain at a certain distance and depth can mitigate liquefaction in soil layers.

Experimental Study on the Reduction Effect of Pit Texture on Disassembly Damage for Interference Fit

After remanufacturing disassembly, several kinds of friction damages can be found on the mating surface of interference fit. These damages should be repaired and the cost is closely related to the severity of damages. Inspired by the excellent performance of surface texture in wear reduction, 5 shapes of pit array textures are added to the specimens’ surface to study their reduction effect of disassembly damage for interference fit. The results of disassembly experiments show that the order of influence of texture parameters on disassembly damage is as follows: equivalent circle diameter of single texture, texture shape and texture surface density. The influence of equivalent circle diameter of single texture and texture shape are obviously more significant than that of texture surface density. The circular texture with a surface density of 30% and a diameter of 100 μm shows an excellent disassembly damage reduction effect because of its perfect ability of abrasive particle collection. And the probability of disassembly damage formation and evolution is also relatively small on this kind of textured surface. Besides, the load-carrying capacity of interference fit with the excellent texture is confirmed by load-carrying capacity experiments. The results show that the load-carrying capacity of the excellent texture surface is increased about 40% compared with that of without texture. This research provides a potential approach to reduce disassembly damage for interference fit.

A study of dispersion of gunshot residue from a frequently used Serbian ammunition cal. 7.65 mm to support selected aspects of casework in North Macedonia

The subject of this research was the inorganic gunshot residue component collected from shooting patterns obtained on woven cotton cloth using a Pietro Beretta model 70 pistol, cal. 7.65 mm and Serbian ammunition for the following muzzle-to-target distances: 25, 50, 75, 100 and 125 cm. For each distance, three rounds of shooting were performed. Particles were lifted within a 10 cm radius of the projectile entrance and automatically analyzed using a scanning electron microscope coupled with an energy dispersion X-ray spectrometry. The obtained data on the populations of particles were analyzed taking into account their numbers, chemical classes and sizes. The results showed an apparent maximum incidence within all particles containing barium at about 50 cm distance. Also, lead particles revealed a distinct behaviour, being dominant at a 25 cm distance, falling below the other chemical classes, and finally becoming dominant again at 125 cm. The analysis of the frequency of occurrence of particles sorted according to their sizes confirmed that the small particle population is the largest, and their distribution in function of the equivalent circle diameter is exponential-like. The obtained results provided knowledge on the distribution of particles in the vicinity of the tested firearm and ammunition cal. 7.65 mm which generally corroborates with similarly studied GSR distributions obtained for the use of pistols cal. 9 mm. This information, together with the examinations of gunshot damages and other types of residues such as soot or unburned propellant grains may support qualitative inferences on shooting distance estimation, especially in cases, when the firearm and cartridges are not available to perform test shooting. In such cases even roughly estimated shooting distance can be helpful, e.g. for confirming or excluding the possibility of self-inflicted injuries or suicide and infer on the mutual position of the shooting stage actors. An example of casework that illustrates intermediate shooting distance estimation is presented.

Effects of floating ice on the flow drag of a circular cylinder with finite length

In present paper, free surface is covered with artificial ice of uniform size. Effects of characteristic sizes of ice, i.e. DL/D = 0.28, 0.56 and 1.08 (DL is diameter of equivalent circle of ice block section and D cylinder diameter), local coverage ratio n and cylinder draught H on drag of ice-water flows around finite length circular cylinder are investigated experimentally. Two hydrodynamic states when Froude number Fr=0.50 in subcritical and Fr=0.99 in supercritical are selected, where Fr=V/gD, V is towing speed and g gravitational acceleration. When Fr=0.99, wave-making increases drag coefficient by 0.1–0.2. For DL/D = 0.56 and 1.08, cross-correlation coefficient between n and drag coefficient exceeds 0.85. Higher n results in greater drag. With H/D increasing from 0.4 to 2.0, momentum transferred from water pushed by cylinder to ice increases, making relative velocity between ice and cylinder decrease and collision contribution to total drag be reduced. While DL/D = 0.28, ice blocks follow water flow closely due to small inertia, making collision between cylinder and ice blocks weak and drag caused by collision insignificant. Also ice-water mixture is more like single phase flow of higher viscosity than water, with drag coefficient almost not affected by draught.

Generation of Nano/Microplastics for Immunological Assessments

This study aimed to develop a method to generate nano/microplastics (NPs/MPs), whose morphology and constituents are clarified for various biological tests. NPs/MPs were generated using a pin-on-disc machine, where a pin made of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), or polyethylene terephthalate (PET) was pressed onto a quartz glass disc. Relative motion between the pin and disc was then applied in a saline solution. An ultraviolet lamp (UV-B) was used to irradiate the frictional surfaces through a quartz glass disc to investigate the degradation of the plastic materials. A microtextured glass surface was used to induce fatigue failure of plastic materials and adjust the crack propagation of plastic materials. UV degradation was confirmed for all the plastic materials and UV irradiation increased the equivalent circle diameter (D) of PE, PVC, and PET but decreased the equivalent circle diameter (D) of PP. However, it was thought that UV irradiation did not affect the aspect ratio (R) and complexity (C) of all plastic materials. The physical degradation mechanism of using the microtextured glass surface may increase the generation of NPs/MPs, and the surface profile of microtextured glass may adjust the crack propagation of plastic material surfaces. Notably, almost all the NPs/MPs generated were fragment-shaped. The NPs/MPs were compared to the particles found in the environment or generated by milling, cutting or chemical degradation in vitro. It was concluded that the fragment-shaped NPs/MPs were similar to the particles found in the environment or generated by milling in vitro, through visual inspection, aspect ratios, and complexity. As the presence of NPs/MPs in the human body can pose a serious health risk, a microchamber device capable of both quantitative and time-dependent assessments of inflammatory cytokine (TNF-α) secretion from human monocyte-derived macrophages (HMDMs) was proposed. The microchamber was constructed with a height of 200 μm and a diameter of 15 mm. This configuration enabled the NPs/MPs to pass near the HMDM, which is important in the phagocytosis of NPs/MPs and contributes to quantitative assessment. Although approximately the same morphological aspects of NPs/MPs were administered, the secretion of TNF-α differed depending on the plastic material.

Hall-Petch Strengthening by Grain Boundaries and Annealing Twin Boundaries in Non-Equiatomic Ni2FeCr Medium-Entropy Alloy

A novel Co-free non-equiatomic Ni2FeCr medium-entropy alloy (MEA) was designed, and the Hall–Petch strengthening by grain boundaries and annealing twin boundaries was investigated. For this purpose, the alloy was prepared by cold rolling and recrystallization at 873–1323 K for 40 min–6 h. Annealing at different temperatures revealed that Ni2CrFe alloy forms a stable face-centered cubic (FCC) solid solution. Mean grain sizes (excluding annealing twin boundaries) and mean crystallite sizes (including both grain and annealing twin boundaries) were determined using the linear intercept method and the equivalent circle diameter in electron back-scattered diffraction (EBSD) soft. Tensile tests at 293 K indicated that the Hall-Petch slopes of grain sizes and crystallite sizes are 673 and 544 MPa μm1/2, respectively, and this contribution was then subtracted from the overall strength to calculate the intrinsic uniaxial lattice strength (90 MPa). Additionally, tensile tests, performed between 293 K and 873 K, revealed that the Ni2CrFe MEA has a stronger resistance to softening at high temperatures. Transmission electron microscopy of deformed specimens revealed the formation of dislocation pile-ups at annealing twin boundaries, indicating that it is also an obstacle to dislocation slip. Furthermore, the thickening of the annealing twin boundary after deformation was observed and illustrated by the interaction between different dislocations and annealing twin boundaries.

Wear Analysis of Tibial Inserts Made of Highly Cross-Linked Polyethylene Supplemented with Dodecyl Gallate before and after Accelerated Aging.

The wear of the tibial insert is one of the primary factors leading to the failure of total knee arthroplasty. As materials age, their wear performance often degrades. Supplementing highly cross-linked polyethylene (HXLPE) with dodecyl gallate (DG) can improve the oxidation stability of tibial inserts for use in total knee arthroplasty (TKA). This study aimed to evaluate the wear resistance of HXLPE supplemented with DG (HXLPE-DG) tibial inserts before and after accelerated aging. HXLPE-DG tibial inserts were subjected to wear testing of up to 5 million loading cycles according to ISO 14243, and the resulting wear particles were analyzed according to ISO 17853. The wear rate, number, size, and shape of the wear particles were analyzed. The average wear rate of the unaged samples was 4.39 ± 0.75 mg/million cycles and was 3.22 ± 1.49 mg/million cycles for the aged samples. The unaged tibial inserts generated about 2.80 × 107 particles/mL following the wear test, but this was considerably lower for the aged samples at about 1.35 × 107 particles/mL. The average equivalent circle diameter (ECD) of the wear particles from the unaged samples was 0.13 μm (max: 0.80 μm; min: 0.04 μm), and it was 0.14 μm (max: 0.66 μm; min: 0.06 μm) from the aged samples. Moreover, 22.1% of the wear particles from the unaged samples had an aspect ratio (AR) of >4 (slender shape), while this was 15.4% for the aged samples. HXLPE-DG improves the wear performance of the material over time. HXLPE-DG is a novel material that has been demonstrated to have antiaging properties and high wear resistance, making it a promising candidate for use in TKA. Nevertheless, the results are preliminary and will be clarified in further studies.

Slag optimization to control CaO increase in inclusions during vacuum degassing of high carbon chromium-bearing steel

ABSTRACT The impacts of slag composition on the CaO content in inclusions during vacuum degassing(VD) treatment are presented. Industrial trials and thermodynamic calculations are used to test, analyze and identify proper optimization method. After optimization, the CaO content of inclusions after VD treatment decreases from 11.3mass% to 7.4mass%. Furthermore, the quantity of CaO containing inclusions in hot-rolled bar decreases from 146 to 41 as well. It is found that the ideal kinetic conditions and the evaporation of Ca during VD process combined trigger and are expected to further enhance the reaction between Al in liquid steel and CaO in slag. Some of the Ca generated from slag will further react with the inclusions which leads to the increase of CaO content in inclusions and equivalent circle diameter of the inclusions. The mathematical correlations among the components of slag in equilibrium with that of liquid steel is obtained by thermodynamic calculations.

Evaluation of different alloying concepts to trace non-metallic inclusions by adding rare earths on a laboratory scale

ABSTRACT Different alloying concepts to trace deoxidation products, mainly aluminium oxides, using rare earth elements (REEs), were tested on the laboratory scale by melting trials with a high-frequency remelting furnace. Lanthanum and Cerium, which belong to the group of light REEs, were used for these experiments. The formed multiphase inclusions were characterized by scanning electron microscopy with energy dispersive spectroscopy. Concerning the higher atomic numbers of REEs, traced non-metallic inclusions (NMIs) seem brighter than the steel matrix compared to deoxidation products. REE-traced aluminium oxides showed a primarily heterogeneous and almost globular morphology. The mean equivalent circle diameter of REE-containing NMIs is for all trials similar and is about 2 µm. The experimental results pointed out that the recovery rates of the various alloying concepts differ only slightly. In contrast, the values mainly depend on the surface-to-volume ratio and the amount of oxygen in the melt.