Distribution Of Inclusions Research Articles

Electrochemical methods to discriminate technology and provenance of Apulian red‐figured pottery. II: EIS

AbstractElectrochemical impedance spectroscopy (EIS) was applied to a set of microsamples of Apulian red‐figured pottery coming from the archaeological sites of Altamura, Arpi, Conversano, Monte Sannace, Taranto, and Pella. EIS data using Fe (CN)63−/Fe (CN)64− as a redox probe yields information on the roughness, porosity, shape, and size distribution of inclusions in the clay body. Impedance parameters after equivalent circuit modeling permit the discrimination of manufacturing in Apulian and Attic modes as well as the characterization of the different archaeological sites.

Effects of thermocapillary convection and shear flow on the distribution of inclusions in half-floating zones

The distribution of inclusions plays a critical role in the performance of crystalline silicon, which is an important raw material for solar panels and semiconductors. To describe the formation of the aggregated inclusions, a three-phase gas–liquid-solid system was designed, in which the gas and liquid phases interact directly through the free surface, and the inclusions interact with them in the liquid. It is worth noting that the inclusions and gas phase did not interact directly. In the gas and liquid phases, the finite volume method was used to solve the Naiver-Stokes equations, and the CLSVOF method was used to track the free surface deformation. The motion of the inclusions was tracked using the Lagrange method. The inclusions and fluid were coupled in two ways: energy and momentum exchange. The numerical results show that the spatial distributions of the inclusion volumetric concentration, number density, and characteristic radius have some features of the recirculation zone. The closer to the center of the liquid bridge, the lower the density of inclusions. When the direction of the shear flow is opposite to that of the thermocapillary convection, this phenomenon is more obvious. This indicates that the crystal quality in the middle region is higher when various parameters are appropriate.

Neutron Tomography Studies of Two Lamprophyre Dike Samples: 3D Data Analysis for the Characterization of Rock Fabric

The rock fabric of two lamprophyre dike samples from the Koy-Tash granitoid intrusion (Koy-Tash, Jizzakh region, Uzbekistan) has been studied, using the neutron tomography method. We have performed virtual segmentation of the reconstructed 3D model of the tabular igneous intrusion and the corresponding determination of dike margins orientation. Spatial distributions of inclusions in the dike volume, as well as further analysis of size distributions and shape orientations of inclusions, have been obtained. The observed shape preferred orientations of inclusions as evidence of the magma flow-related fabric. The obtained structural data have been discussed in the frame of the models of rigid particle motion and the straining of vesicles in a moving viscous fluid.

Prediction on the three-dimensional spatial distribution of the number density of inclusions on the entire cross section of a steel continuous casting slab

In the current study, the LES turbulent model, heat transfer, solidification, species transport model, and discrete phase model (DPM) were coupled to investigate the three-dimensional transient flow, temperature, solidification, segregation, and inclusion transport during the slab continuous casting (CC) process. The number, size, and spatial distribution of inclusions on the entire cross section of the CC slab were successfully predicted using the coupled full solidification model, DPM, and capture criteria at the solidification front. The improved capture criteria that considering the primary dendrite arm spacing (PDAS), different forces acting on inclusions, and the critical capture speed, successfully eliminated the banded distribution characteristics of inclusions under the simple capture criterion. The prediction results were in good agreement with the detection results. Four accumulation zones of inclusions along the thickness of the CC slab were predicted, including the 1/4 thickness and 3/4 thickness from the loose side, and the layer beneath the surface of the CC slab. Two accumulation zones near the layer beneath the surface of the CC slab were issued from the double roll flow pattern in the CC strand. The probability of inclusions contacting the solidification front in the upper recirculation zone increased, increasing the entrapment rate. The accumulation zones near the 1/4 thickness and 3/4 thickness from the loose side were corresponded to the peak value of the Marangoni force on inclusions at the 1/4 thickness and 3/4 thickness from the loose side. The Marangoni force increased the probability of inclusions being pushed to the solidification front. In addition, the accumulation near the 1/4 thickness from the loose side became more severe as the diameter of the inclusions increased due to the buoyancy.

Grassroot Engagement in Local Economic Development: A Case Study of eThekwini Metropolitan Municipality

This paper explores the best mechanisms that should be adopted and implemented to ensure successful implementation of Local Economic Development (LED) through a multi stakeholder engagement process. The municipalities should not only provide services and encouragement of socio-economic growth but they should also enhance the multi-stakeholder engagement in society to improve the livelihoods of communities. Local Economic Development (LED) as a global phenomenon seeks to create employment, reduce poverty and promote inclusive and equitable distribution of wealth for local communities. However, LED initiatives are characterised as a failure when they do nothing to alleviate the high rate of poverty, unemployment, and illiteracy. This study sought to explore the nature of multiple stakeholders engagement in the implementation of LED projects in eThekwini Municipality. Using a sequential mixed method research, the study mixed both quantitative and qualitative techniques. Findings revealed a high level of multi-engagement among those politically affiliated or the elite while people at the grass-root are not well engaged. Another reported problem was the top-down approach and pseudo-participation of other stakeholders, particularly, the "have nots" in the society. These findings should be useful to local government stakeholders as well as to policymakers by involving all sectors of the society in order to encourage the sustainable provision of services to communities and to stimulate socio-economic growth. This study revealed the need to enhance public participation and the need to move away from 'tokenist' approaches reported in the study. These findings also suggest the need for future scholarly investigation.

Beneficiation properties of ash-and-slag dumps

Purpose. Development of a mathematical model for the indices of TPP ash-and-slag waste separation in closed flotation circuit when applying recleaning operations of enriched product. Methodology. The methods for calculating separation indices using the separation characteristics of separation processes and calculating the indices of the release of valuable mineral using statistical relationships between the particle size of the inclusion, ash content and particle size distribution function were used. Findings. Separation characteristics of rough and recleaning flotation operations were preliminarily determined experimentally, relations that allow calculating the indices of the release of coal particles in ash-and-slag dumps were defined, based on which the functions of particle distribution by their content of valuable mineral fractional composition were found. The separation characteristics of the connections of the separation blocks, including several operations of cleaning of the enriched froth product, were determined. Calculations to determine the quantitative and qualitative separation indices were performed. Originality. Analytical relationships to determine the indices of the release of coal inclusions in the process of material from ash-and-slag dumps grinding were obtained. Practical value. The established dependencies make it possible to justify the required grinding coarseness to achieve the specified parameters of the enrichment process based on the values of the beneficiation properties of ash-and-slag dumps.

Influence of Non-Metallic Inclusions on Local Deformation and Damage Behavior of Modified 16MnCrS5 Steel

This work investigates a ferrite matrix with multiple non-metallic inclusions to evaluate their influence on the global and local deformation and damage behavior of modified 16MnCrS5 steel. For this purpose, appropriate specimens are prepared and polished. The EBSD technique is used to record local phase and orientation data, then analyze and identify the size and type of inclusions present in the material. The EBSD data are then used to run full phase crystal plasticity simulations using DAMASK-calibrated material model parameters. The qualitative and quantitative analysis of these full phase simulations provides a detailed insight into how the distribution of non-metallic inclusions within the ferrite matrix affects the local stress, strain, and damage behavior. In situ tensile tests are carried out on specially prepared miniature dog-bone-shaped notched specimens in ZEISS Gemini 450 scanning electron microscope with a Kammrath and Weiss tensile test stage. By adopting an optimized scheme, tensile tests are carried out, and local images around one large and several small MnS inclusions are taken at incremental strain values. These images are then processed using VEDDAC, a digital image correlation-based microstrain measurement tool. The damage initiation around several inclusions is recorded during the in situ tensile tests, and damage initiation, propagation, and strain localization are analyzed. The experimental results validate the simulation outcomes, providing deeper insight into the experimentally observed trends.

Characteristics of Mineralization-Forming Fluid and Metallogenic Mechanism for the Mianhuakeng Uranium Deposit in South China: Constraints from In Situ Geochemical Signatures and Sulfur Isotopes of Syn-Mineralization Pyrite and Pitchblende

The Mianhuakeng deposit is the most representative granite-related hydrothermal vein-type uranium deposit in South China; however, the characteristics of the mineralization-forming fluid and metallogenic mechanism are still less constrained. To address the scientific problems above, we investigated the trace element chemistry and sulfur isotope compositions in syn-mineralization pyrite and pitchblende from the Mianhuakeng uranium deposit. The trace element chemistry shows that the mineralization in the Mianhuakeng deposit belongs to an intermediate-to-low temperature hydrothermal system, which is consistent with the homogenization temperature distribution of fluid inclusions. Redox-sensitive elements (such as Co and Se) in syn-mineralization pyrite suggest a reductive nature of the mineralization-forming fluids. The fractionation between light and heavy REE in pitchblende from the Mianhuakeng deposit is most similar to those from the Changjiang pluton. The pronounced negative Eu anomaly is coincident with mineralization-bearing granites. The δ34S values of syn-mineralization pyrite range from −10.2 to −1.4‰, which is higher than those values of pyrite from granites near the studied area and lower than the δ34S values of pyrite from diabase in the ore district. The REE signatures of pitchblende and sulfur isotope composition of syn-mineralization pyrite suggest that the major U source for the Mianhuakeng deposit is most likely the Changjiang pluton, probably accompanied by the incorporation of mantle-derived fluids. The circulations of CO2-rich hydrothermal fluids leached uranium from granite source rocks, especially from the Changjiang pluton. The change of physicochemical conditions of the mineralization-forming fluid resulted in the deposition of the uranium minerals in favorable structural traps to form the hydrothermal vein-type Mianhuakeng uranium deposit.

Oriented Magnetite Inclusions in Plagioclase: Implications for the Anisotropy of Magnetic Remanence

AbstractMicron to sub‐micron sized ferromagnetic inclusions in rock forming silicate minerals may give rise to particularly stable remanent magnetizations. When a population of inclusions have a preferred crystallographic or shape orientation in a rock, the recorded paleomagnetic direction and intensity may be biased by magnetic anisotropy. To better understand this effect, we investigated plagioclase grains from oceanic gabbro dredged from the Mid‐Atlantic Ridge at 11°–17°N. The plagioclase grains contain abundant needle and lath shaped magnetite inclusions aligned along specific directions of the plagioclase lattice. Electron back scatter diffraction and anisotropy of magnetic remanence measurements are used to correlate the orientation distribution of the magnetite inclusions in the host plagioclase that contains multiple twin types (Manebach, Carlsbad, Albite, and Pericline) with the bulk magnetic anisotropy of the inclusion‐host assembly. In non‐modified plagioclase, the anisotropy ellipsoid of magnetic remanence has oblate shapes that parallels the plagioclase (010) plane. It is suggested that recrystallization of magnetite inclusions during hydrothermal overprint shifts the relative abundance of the inclusions pertaining to the different orientation classes. We show that the maximum axis of the anisotropy ellipsoid of magnetic remanence parallels the plagioclase [001] direction, which in turn controls the recorded remanent magnetization direction. Our results are relevant for paleointensity and paleodirection determinations and for the interpretation of magnetic fabrics.

Characterization of the morphological evolution of MnS inclusions in free-cutting steel during heating

The size, morphology and distribution of MnS inclusions in the sulfur bearing free-cutting steel are the key factors to determine the performance of the free-cutting steel. It is thus important to accurately characterize and control the morphology of the MnS inclusions in the steel. The morphology of MnS inclusions are complex during rolling due to their good plasticity. Additionally, the morphology of the MnS inclusions would change during heating due to the decomposition and mass transfer of the Mn and S in the steel matrix. The traditional metallographic for characterizing the MnS inclusions on the cross-sections only reveal the local characteristics of the inclusions and results in misunderstanding of the real morphologies. In this study, the three-dimensional (3D) morphology of the MnS inclusions in the sulfur bearing free-cutting steels is characterized by using the X-ray Micro-CT in the beamline of BL13W1 at Shanghai Synchrotron Radiation Facility (SSRF). The stereology and morphological evolution of the MnS inclusion during heating are characterized and analyzed based the 3D observation. The number of MnS inclusions increased more than twice, the length of the inclusion with sizes less than 9 μm increased from 25.79% to 71.28%. The anisotropy index was reduce from 2.30 to 1.04 due to the spheroidization of the MnS inclusions during heating. The mechanism of the morphological evolution of the MnS inclusions is discussed on basis of the local chemical potential of the MnS caused by the variation of the curvature on the surface of the inclusions.

Composition of Organosilicate Coatings High-Temperature Breakdown Products and Their Distribution in the Weld

The construction assembly and the repair of steel constructions painted with protective coatings are often carried out using arc welding. During the welding process, the coating in the weld zone is degrading. The protective coatings breakdown products are involved in the pore and non-metallic inclusion formation in the weld, the composition and distribution study of which makes it possible to analyze the reactions occurring during the welding. In this study, welding beads were deposited on the coated sheet surface by MAG welding. The distribution of inclusions (the average diameter and the relative content) along with the porosity in different bead zones were investigated by optical and scanning electron microscopy and digital image processing, and the chemical composition of inclusions was determined using energy-dispersive X-ray spectroscopy. The amount of diffusible hydrogen in the deposited metal was estimated with the vacuum method. In this work, four organosilicate coatings grades, differing in their purpose and heat resistance, were used, and their effect on the weld was studied.

Self-consistent description of the halo nature of 31Ne with continuum and pairing correlations

Background: A relativistic structure model has previously been used to predict a halo structure for 31Ne (Zhang et al 2014 Phys. Lett. B 730 30), consistent with halo signatures from measured reaction cross sections of Ne isotopes bombarding Carbon targets. However, previous attempts to calculate those cross sections with reaction models were missing contributions from resonances and pairing correlations in their structure input. Purpose: Use a reaction model with our relativistic fully microscopic structure model input to predict these cross sections and momentum distributions and analyze for possible halo signatures. Methods: Structure input for exotic Ne isotopes were obtained via the analytical continuation of the coupling constant (ACCC) method based on the relativistic mean field (RMF) theory with Bardeen–Cooper–Schrieffer (BCS) pairing approximation, the RAB approach. Total reaction cross sections, one-neutron removal cross sections, and momentum distributions of breakup reaction products were calculated with a Glauber model using our relativistic structure input. Results: Our predictions of total reaction and one-neutron removal cross sections of 31Ne on a Carbon target were significantly enhanced compared with those of neighboring Neon isotopes, agreeing with measurements at 240 MeV/nucleon and consistent with a single neutron halo. Furthermore, our calculations of the inclusive longitudinal momentum distribution of the 30Ne and valence neutron residues from the 31Ne breakup reaction indicate a dilute density distribution in coordinate space, another halo signature. Conclusions: We give a full description of the halo nature of 31Ne that includes a self-consistent use of pairing and continuum contributions that makes predictions consistent with reaction cross section measurements. This approach can be utilized to determine the halo structure of other exotic nuclei.

Three-dimensional observation of GEMS grains: Their high-temperature condensation origin

GEMS (Glass with Embedded Metal and Sulfides) grains found in interplanetary dust particles are considered one of the most primitive materials in the Solar System, yet questions remain on how they formed. It has been suggested that GEMS grains are products of radiation processing and amorphization of sulfide and silicate mineral grains in the interstellar medium. Alternatively, GEMS grains are proposed to be disequilibrium condensation products in late-stage protosolar disks. We examined the 3D distributions of elements and inclusions within GEMS grains using TEM (transmission electron microscopic)-tomography to better constrain their possible formation processes. We found some core–shell particles composed of metals and amorphous silicates and observed a binary distribution of Mg/Si in amorphous silicates of GEMS grains. These properties are highly similar to the features of experimental condensation products. Furthermore, the location of sulfides only on the surface of GEMS and their larger sizes than metals are also consistent with the condensation experiments, where sulfides formed by sulfidation of metal grains with S-bearing gas species. Textures showing aggregation and possible coalescence of primary grains were also observed. Therefore, we conclude that GEMS grains are condensates from gas at high temperatures and some of them were aggregated.

Effect of Al2O3 in Refining Slag on the Cleanliness and Fatigue Property of Ultra-low-carbon Automotive Steel

The influence of Al2O3 content in refining slag on the cleanliness and fatigue property of ultra-low-carbon (ULC) automotive steel were investigated based on the industrial experiments. The inclusion-adsorption capacity of the refining slag was calculated and the total [O] (T.O) content of ULC automotive steel was measured. The number density, size distribution and morphology of inclusions were analyzed and their effects on the cleanliness and fatigue property of ultra-low-carbon (ULC) automotive steel were investigated. The results showed that as the Al2O3 content in refining slag increased from 19.92% to 39.73%, the inclusion-adsorption capacity of ULC automotive steel decreased from 210.30 down to 57.12, and the fatigue life from 1.4x104 down to 0.9x104 cycles, while the T.O content of steel increased from 12 up to18 ppm and the inclusion number density from 4 up to 9 per mm2.

Non-metallic inclusions in a superalloy during refining through cold crucible levitation melting process

Oxide and nitride inclusions in a Ni-based superalloy during the cold crucible levitation melting (CCLM) process were investigated towards a better understanding for the removal of inclusions from the metal. The number, morphology, size distribution and spatial distribution of inclusions were characterized using an automated scanning electron microscopy with energy-dispersive X-ray spectroscopy. Inclusions in the alloy were efficiently agglomerated and removed by floating during CCLM process. Inclusion clusters as big as 30-400 ?m were observed. Oxide clusters were efficiently floated during pouring process. The removal ratios of oxides were about 21% without pouring and 62% with pouring, respectively. Additionally, CCLM promotes the separation of oxides from nitrides. The effect of CCLM on the removal of nitride inclusions is not such evident compared with oxides. The mechanism of inclusion removal during CCLM was clarified.

Production of strange particles in jets and underlying events in pp collisions at √S = 13 TeV with ALICE

The production of strange KS0, Λ and multi-strange (Ξ± and Ω±) particles in jets and the underlying event in pp collisions at √S = 13 TeV has been studied with ALICE at the LHC. The pT-differential density of the particles produced in a jet is compared to the inclusive distribution. The corresponding (Λ + Λ¯)/2KS0 and (Ξ− + Ξ¯+)/(Λ + Λ¯) ratios in jets as a function of pT are also reported in this work. The pT-differential density distribution of hadrons associated with jets decreases slower than the one reported for inclusive particle production. The ratios measured in jets show a clear difference when compared to the inclusive ones at the intermediate pT range. The results provide an opportunity to test the strange and multi-strange particle production mechanisms with hard scattering.

The effect of different deoxidation processes on the inclusions characteristics in cold drawn tubing steel

ABSTRACT The non-metallic inclusions of cold-drawn tubing steel with different deoxidation processes were carried out in this study. The morphologies, compositions and size distribution of oxide inclusions in two heats were obtained by FE-SEM&EDS. The evolution of inclusion types in SM/AC process and SMA/C process were compared. In addition, it was summarized that the removed inclusion of SM/AC process was relatively more at LF station, while the removed inclusion of SMA/C process was mainly at VD station, which is closely related to the calcium treatment intensity at VD station. Moreover, kinetic model calculations of inclusion behaviour were carried out. Taking molten steel-slag-inclusion-refractory four-phase equilibrium into account, and considering the aggregation, floatation, remove and modification of inclusion. The results can well explain the existence of inclusions in the actual production process and can guide the removal of inclusions in different deoxidation processes and to know the removal limits.

Calculated-experimental model of distribution of non-metallic inclusions in the metal of welds by sizes

The Paton Welding Journal, 2021, №12. International Scientific-Technical and Production Journal «The Paton Welding Journal» «The Paton Welding Journal» has been published monthly since 2000 in English, ISSN 0957-798X. «The Paton Welding Journal» is a cover-to-cover English translation of the «Avtomaticheskaya Svarka» (Automatic Welding) journal. The «Avtomaticheskaya Svarka» journal has been published monthly since 1948 in Russian, ISSN 005-111X.

Technology penetration and human development nexus in middle-income countries: the synergy effect of inclusive resources distribution

ABSTRACT This paper intends to examine how interactions between equal distribution of resources and the information and communication technology (ICT) influence inclusive human development (inequality-adjusted human development) for 81 countries from middle-income countries within the period 2005–2017. We use a double-censored Tobit regression as it accounts for the dependent variable with a limited range. It exhibits the behavior that is consistent with the method of estimation. We employ the instrumental variable (IV) for the independent variables of interest to deal with simultaneity or reverse causality due to endogeneity. In light of established findings for this study, we conclude that equal distribution of public goods such as technologies could play a critical role in promoting inclusive human development. Supplementary policy repercussions are highlighted.

Influence of batch-to-batch material variations on grindability of a medium‑carbon steel

This study addresses the influence of material variations on the grindability of crankshaft steel. Most previous studies on the effect of material microstructure on grindability involve comparisons of significantly different steel grades. This study, in contrast, is focused on batch-to-batch grindability variations for one steel grade, a scenario frequently occurring in industry where batches from different steel makers are fed into a production line. For this purpose, a batch made of recycled steel and a batch made of ore-based steel were compared with regards to microstructure and grindability under identical grinding and dressing conditions. Although both batches met the same material specifications, microstructural variations were identified in terms of grain size and micro-constituents (inclusions, carbonitrides). While specific grinding energy, residual stress and full-width at half-maximum profiles of ground surfaces were the same for both batches, the recycled batch showed different and unfavorable variation in wheel wear and Barkhausen noise (BN) response. Larger fractions of oxide inclusions and larger grain sizes (affected by carbonitrides) were present in the recycled batch, which were the likely reasons for the differences in wheel wear and BN response, respectively. These findings may aid grindability improvement by steel-grade adjustments, e.g. modification of the distribution and type of inclusions and/or amount of elements forming carbonitrides. Furthermore, the results highlight the importance of understanding and controlling material microstructure, as existing in-line quality by BN control may not always be able to correctly indicate surface integrity, which could lead to misinterpretations (e.g. false part-rejection on the assumption of grinding burn).