Grains In Bulk Research Articles

Influence of rice husk dosage on PM emissions during the co-firing of coal with refuse derived fuel

A self-designed drop tube furnace (DTF) was constructed to investigate the particulate matter (PM) emissions generated from blending 0–30 wt% refuse derived fuel (RDF) and 0–20 wt% rice husks (RH) with bituminous coal during co-firing. The physiochemical characteristics of PM were determined using XRD, XRF, and SEM-EDS, and the creation of the liquid components at varying temperatures was investigated using theoretical thermodynamic calculations based on fuel composition and combustion atmospheres. The results demonstrated that blending 0–30 wt% RDF with coal did not result in significant PM emissions. PM0.5 and PM2.5 yields declined by 31.5% and 39.5%, respectively, with the addition of 20 wt% RH. By solely adding RDF, more Ca-Al-Si and K/Ca-Si formed viscous surfaces or particle bodies that could capture Ca/K vapor released from the volatiles of RDF in the gas bulk. Si-rich and Al-Si species from coal were consumed and transformed into Na/K-Ca-Al-Si to enhance the production of the liquid phase by the abundant Si in the volatiles of RH. Two possible paths of mineral transformations during co-firing were discussed to prove that alkali metals and alkaline earth metals preferentially condensed on Si-rich and Al-Si species to form liquid substances and capture the vapor and grains in the gas bulk, rather than combining with nonmetallic elements to generate precursors for PM generation via the evaporation–condensation mechanism. This study contributes to the search for an efficient pathway to realize simultaneous waste utilization and greenhouse gas reduction.

Real‐time detection of Fusarium infection in moving corn grains using YOLOv5 object detection algorithm

AbstractReal‐time inspection and removal of individual Fusarium head blight (FHB) infected corn grains from the processing lines has been a challenging issue due to the bulk handling and smaller kernel size. In this study, four different variants (small(s), medium(m), nano(n), and large(l)) of You Only Look Once (YOLO) version 5 object detection technique were trained for the detection of Fusarium infection in a moving monolayer of touching and non‐touching corn grains. The YOLOv5 object detection models were evaluated for their performance in detecting FHB infection in individual corn grains. A heterogeneous dataset containing images and video frames of healthy and FHB infected corn grains in different illuminations was utilized. The mean average precision calculated at Intersection over Union threshold of .5 (mAP@50) was 99%, 98%, 95%, and 96% for YOLOv5‐s, YOLOv5‐m, YOLOv5‐n, and YOLOv5‐l models, respectively. The detection speed in videos was 3.9, 1.6, 9.8, and .8 frames per second for YOLOv5‐s, m, n, and l models, respectively. For non‐touching grains, all four variants of the YOLOv5 model showed 100% precision, but for touching grains, all variants showed false negatives in detection of FHB infection, especially on overlapping kernels. The recall values were found to be 98%, 99%, 96%, and 97% for YOLOv5‐s, m, n, and l models, respectively. The best combination of mAP, detection speed, and lower false negatives was achieved by the YOLOv5‐m model. YOLOv5‐m has the potential for use in real‐time detection of Fusarium infection in corn grains apart from lag time in videos.Practical ApplicationThe developed video analysis technique based on YOLOv5 object detection method will be beneficial for the accurate identification of Fusarium infected corn grains in bulk handling facilities. The individual FHB infected grains could be detected on processing lines and could be used for real‐time inspection replacing the random sampling techniques currently used, thereby preventing the entry of Fusarium mycotoxins in the food chain. For non touching corn grains, all the YOLOv5 model variants showed a 100% precision in identifying the healthy and FHB infected grains. For touching grains, YOLOv5‐m model showed the best combination of mAP, detection speed, and lower false negatives proving appropriate for inspection on moving conveyor belts. The nano model with the lightweight architecture installed in portable devices can be used for immediate detection of FHB infection without lag time.

Synthesis of c-axis textured CaKFe4As4 superconducting bulk via spark plasma texturing technique

Grain alignment is a key factor that determines the performance of a superconducting bulk. In this study, the spark plasma texturing (SPT) technique was used to fabricate a CaKFe4As4 superconducting bulk. X-ray diffraction and electron backscatter diffraction revealed that the c-axes of the CaKFe4As4 grains in the SPT bulk are aligned, demonstrating that the SPT technique is effective in achieving c-axis texture. In addition, chemical composition analysis showed that oxide impurities, which affect the grain boundary characteristics that determine the inter-grain critical current density (Jc), are randomly distributed in the SPT bulk. Magnetization measurements showed high Jc values of the SPT bulk, reaching 127 kA cm−2 and 26 kA cm−2 at 4.2 K under a self-field and magnetic field of 5 T, respectively. These results suggest that the SPT technique is a promising approach for obtaining a high-performance superconducting bulk material for high-field applications.

Effects of the addition of RPF and woody biomass on PM emissions during co-firing with coal

Two Cl-free refuse plastic and paper fuels (RPFs) produced by hydrothermal treatment with Ca(OH)2, as well as two biomasses, were co-fired with bituminous coal in a lab-scale drop tube furnace (DTF). The results indicate that the addition of biomass and RPF partially reduced the emission of SO2, which can readily cause corrosion, deposition and pollution. For the biomass co-firing, the particulate matter (PM) emissions from the black pellet (BP) series were 5.0% higher than those from the white pellet (WP) series because more sticky particles were formed with the increment of Ca-Al-Si and K-Al-Si, which absorbed alkali vapor and fine grains in the gas bulk to inhibit the PM emissions. For RPF, the major origins of sticky particles turned into Ca-Al-Si and Ca-K-Al-Si, the proportion of which was dramatically higher than that from the biomass, resulting in a stiffer suppression of PM formation. In general, the promotion of Ca from additives conversely restrained its transformation into PMs during both biomass and RPF co-firing. It can be concluded that the co-firing of RPF with bituminous coal provides an alternative approach to simultaneously control the emissions of greenhouse gases, gaseous pollutants and PM while remediating plastic waste.

Surface mechanical attrition treatment of additively manufactured 316L stainless steel yields gradient nanostructure with superior strength and ductility

Surface severe plastic deformation (S2PD) of additively manufactured/three-dimensional (3D) printed metallic parts is gaining increased attention as a post-manufacturing operation to enhance the material performance in a wide variety of applications. Surface mechanical attrition treatment (SMAT) is an S2PD technique that can yield a nanostructured surface layer induced by compressive stresses and work hardening. In the present study, SMAT was performed on 316L (austenitic) stainless steel (SS) processed by selective laser melting (SLM), and the consequent effects on mechanical response were investigated. The underlying mechanisms of microstructural evolution leading to the formation of nanocrystalline grains resulting from SMAT in SLM 316L SS are elucidated. The interactions between twins and deformation bands act as potential sites for impeding the movement of dislocations, which in turn leads to the formation of stacking faults, twinning, and occasionally transform to a different crystal structure. Twin-twin and/or twin-deformation band intersections sub-divide the matrix grains into smaller cells or low-angle disoriented blocks, which result in the formation of low-angle grain boundaries and finally in nanocrystallization at the surface. The size of nanocrystalline grains increases progressively with depth from the surface to micrometer size grains in bulk. The gradient nanostructure in the additively manufactured alloy after SMAT imparts an unusual combination of strength and ductility that markedly exceeds that of conventional, bulk nanostructured, or even high-performance 316L SS (containing nanoscale deformation twins embedded in submicron-sized austenitic grains obtained by dynamic plastic deformation processes). Analytical models revealed that strengthening results from a combination of grain boundaries and dislocations. The results of the present investigation pave the way for engineering high-performance SS for a variety of engineering applications.

Microstructure and shear behavior of Sn58Bi/Cu solder joint enhanced by SnAgCuBiNi bump

In order to improve the mechanical behavior of the low-temperature [Formula: see text] (SnBi) lead-free solder joint, the [Formula: see text] (SACBN) solder ball with the diameter of 400 [Formula: see text]m was pre-soldered on Cu to obtain the SnBi/SACBN/Cu composite joint. The microstructure and shear behavior of the solder joints were investigated. Experimental results indicate that SnBi solder is well bonded on the SACBN bump due to the elemental diffusion and dissolution between the molten SnBi and solid SACBN bump during the soldering process. The addition of the SACBN bump shows a significant effect on the formation and growth of the [Formula: see text]-Sn grains in the SnBi bulk. Compared with the SnBi/Cu joint, the SnBi bulk in the composite joint shows enlarged [Formula: see text]-Sn dendritic grains. Meanwhile, the interfacial intermetallic compound (IMC) layer transforms from Cu6Sn5 into (Cu, Ni)6Sn5. Among these three solder joints, the shear strength of the SACBN/Cu joint is the highest, reaching 86.7 MPa. The shear strength of the SnBi/Cu solder joint is enhanced by the SACBN bump from 68.2 MPa to 75.2 MPa. Additionally, the addition of the SACBN bump shows a positive effect on suppressing the brittleness of the SnBi/Cu solder joint.

Microstructure, hardness, and shear behavior of Sn3.0Ag0.5Cu–Sn58Bi composite solder joint

In this study, Sn3.0Ag0.5Cu-Sn58Bi (SAC-SnBi) composite solder joint was obtained by two-step soldering process. The microstructure, hardness, and shear performance of the composite solder joint were investigated in comparison with the eutectic Sn58Bi (SnBi) and SnAgCu (SAC) solder joints. Experimental results showed that the SAC-SnBi had similar intermetallic compound (IMC) morphology and thickness with the SAC solder joints. Compared with the eutectic SnBi solder, the large Bi-rich matrix transforms into tiny Bi-rich grains in the SAC-SnBi solder bulk. Tiny Bi-rich grains, Cu6Sn5, and Ag3Sn distribute uniformly in the composite solder bulk. As the SnBi bulk melts into the SAC solder during the second soldering process, the formation and growth of large β-Sn dendritic in SAC solder is suppressed in the composite solder. Therefore, the SAC-SnBi composite joint shows higher hardness and shear strength than the other two.

Carbon contents design and characterization of gradient cemented carbonitrides with nano-TiN addition

Gradient cemented carbonitrides with brittle cubic phase depleted in the surface layer were prepared in the paper. This gradient material is believed to be a promising composite used as the substrate of a coated insert for machining operation. The formation of gradient layers stems from nitrogen decomposition. In this paper, nano-TiN was introduced as a nitrogen supplier, and besides it functioned as a grain growth inhibitor of (Ti,W)C cubic phase. The microstructure, fracture morphology, mechanical and magnetic properties of the gradient cemented carbonitrides with carbon contents from 6.04wt% to 6.34wt% were investigated systematically. The results show that lattice parameters of (Ti,W)C in the transit zone increase due to more Ti solid solution when the gradient layer thickens. (Ti,W)C grains in the inner bulk are refined effectively by nano-TiN. Intergranular fracture along WC grain, transgranular fracture of (Ti,W)C grains, and the tearing of binder are found in the bulk of the gradient cemented carbonitride. When cracks encounter the gradient layer, they grow from new origins and a macroscopic boundary is formed between the gradient layer and the bulk. The transverse rupture strength is promoted with the carbon contents increased, and its stability is also increased. Additionally, the microhardness of the gradient cemented carbonitride is correlated closely with the Ti and Co distribution.

Características nutricionais e perdas no processo fermentativo de silagens de milho, colhidas em diferentes estádios reprodutivos com diferentes processamentos de grãos

The aim of this study was evaluate the harvest of corn plant in different reproductive stages and different processing grain about losses and nutritive value of silages. Significant differences in the stage of harvest showed up in lower (P <0.05) for dry matter (26.70% against 34.78%) and higher values for contents of mineral matter (4.35 % against 3.87%), acid detergent fiber (32.63% vs. 23.36%) and neutral detergent fiber (52.06% against 42.07%) in the level of harvest dough (R3 ) compared to the level of hard grain (R5), respectively. High dry matter losses were found at stage R3, which are the dimensions of 14.59% and 20.06% respectively to silages with and without grain processor, significantly different (P> 0.05) results found for the R5 stage, which had an average loss of around 5.77%, demonstrating that silage harvested at R5 stage, allow greater dry matter recovery and hence greater savings for the farmer. Regarding the parameter of losses of crude protein, there were no significant differences for the effects of isolated or associated stages of harvesting and processing of grain in corn silage. Large differences can be perceived as the loss of neutral detergent fiber and loss of acid detergent fiber silage, justified by the increase in the levels of acid detergent fiber in the average share of 22.96% in the silage harvested at stage R3 and reduction in their concentration with an average of 4.60% for the R5 stage. No significant differences were observed (P <0.05) for the particle size as the different treatments, only significance being observed as the participation of whole grains in bulk, this ranging on average from 2.59% to 10.27% dry matter, respectively for stage R3 and R4-R5. In general, silage maize plant reproductive stage R5 provided smaller losses nutritious silage storage and greater accumulation of grains in bulk when compared to R3 stage.

Improvement of Critical Current Density in YBa2Cu3O7-δ Superconductor with Nano TiO2 Addition

The optimization of flux line pinning in superconductors is one of the most efficient ways to improve the transport properties of these materials. In this work, we have examined the effectiveness of an insulating nano particle inclusion in a type II superconductor as a pinning center with a size close to the coherence length, ξ. We report on measurements of the superconducting properties of YBa2Cu3O7-δ bulk superconductors with different weight % of nano particles of TiO2 contents (x = 0–3wt %) prepared by the modified combustion route. The microstructure of bulk YBCO added with nano particles was characterized by scanning electron microscopy. Sub-micron, randomly oriented particles of this phase were found to form around grain boundaries and within YBCO grains in bulk sintered pellets. It is observed that the critical current density is higher by a factor of 3 and the Jc–B behavior is remarkably improved in samples with nano additions. However, the superconductor transition temperature (Tc) slightly decreases from 92K to 90.5K. The flux pinning force is enhanced by 8 times that of pure YBCO sample. Thus these nano particles are effective flux pinning centers and enhance the transport critical current density at liquid nitrogen temperature for an applied magnetic field. The experimental results suggest that the added nano-sized TiO2 particle may have high pinning efficiency at a temperature around 77K.

Synthesis of Mg2Si for thermoelectric applications using magnesium alloy and spark plasma sintering

Magnesium silicide was synthesized through a solid-state reaction at 400°C between chips of commercially pure Mg or AZ31 magnesium alloy and silicon fine powders. The use of alloy AZ31 allows Al to be introduced as a dopant. The synthesized silicide powders were consolidated by spark plasma sintering at 750°C. X-ray diffraction and scanning electron microscopy were used to confirm the phase purity and structural evolution from powder to bulk material. The crystalline grains in the Mg2Si bulk were identical to the raw Si powder in size. The Al impurity increased the electrical conductivity of Mg2Si while the Seebeck coefficient was lowered. The thermal conductivities were almost the same for Mg2Si and doped Mg2Si. The optimal thermoelectric figure of merit (ZT) was 0.58 at 844K in the n-type Al-doped Mg2Si material. Inductively coupled plasma emission spectroscopy was employed to determine the concentration of Al dopant.

Nanorod Self-Assembly in High Jc YBa₂Cu₃O₇-x Films with Ru-Based Double Perovskites.

Many second phase additions to YBa2Cu3O7−x (YBCO) films, in particular those that self-assemble into aligned nanorod and nanoparticle structures, enhance performance in self and applied fields. Of particular interest for additions are Ba-containing perovskites that are compatible with YBCO. In this report, we discuss the addition of Ba2YRuO6 to bulk and thick-film YBCO. Sub-micron, randomly oriented particles of this phase were found to form around grain boundaries and within YBCO grains in bulk sintered pellets. Within the limits of EDS, no Ru substitution into the YBCO was observed. Thick YBCO films were grown by pulsed laser deposition from a target consisting of YBa2Cu3Oy with 5 and 2.5 mole percent additions of Ba2YRuO6 and Y2O3, respectively. Films with enhanced in-field performance contained aligned, self-assembled Ba2YRuO6 nanorods and strained Y2O3 nanoparticle layers. A 0.9 µm thick film was found to have a self-field critical current density (Jc) of 5.1 MA/cm2 with minimum Jc(Θ, H=1T) of 0.75 MA/cm2. Conversely, Jc characteristics were similar to YBCO films without additions when these secondary phases formed as large, disordered phases within the film. A 2.3 µm thick film with such a distribution of secondary phases was found to have reduced self-field Jc values of 3.4 MA/cm2 at 75.5 K and Jc(min, Θ, 1T) of 0.4 MA/cm2.

MECHANICAL PROPERTIES OF WHEAT GRAINS

Mechanical properties of three new varieties of Egyptian wheat grains Giza-168, Sakha-93 and Banisuif-1 were investigated at different levels of moisture content ranged between 8 to 19 % w.b. Mechanical tests including bulk and particle compression (stress-strain), particle shear and particle hardness were conducted to obtain grains properties. Statistical analysis was performed to obtain the regression coefficient between the studied properties and the moisture content of grains. Mechanical properties included hardness (kg), shear stress (MPa), initial elasticity modulus (MPa) for grains in bulk and in particle, elasticity modulus (MPa) for grains in bulk and in particle, maximum stress(MPa), bioyield point and breakage energy (kJ/m3).

Equal Channel Angular Pressing of Al Alloy AA2219

Severe plastic deformation processes (SPD) are gaining importance as advanced materials processing techniques and hold immense potential in obtaining ultra fine-grained high strength materials. Among the SPD techniques, Equal channel angular pressing (ECAP) has its own merits to produce materials with ultra fine grains in bulk with better mechanical properties. The material deforms with high level of plastic strain inside the channel resulting in grain refinement of the output material with improvement in mechanical properties. A very viable die configuration was conceptualized and die was made with 1200 channel angle. Processing of 25 mm dia. of Al alloy AA2219 at room temperature was successfully carried out and grain refinement was observed. The mechanism of grain refinement has been studied using optical and transmission electron microscopy (TEM). It was observed that low energy dislocation structure (LEDS) forms concurrently with sub-grain structure due to dislocation rearrangements, which provide stability to the evolving sub-grain structure. Dislocation mobility is hindered by the presence of precipitates and / or intermetallic dispersoids present in the matrix and results in presence of dislocations in grain interiors. The pile up of dislocations at intermetallic dispersoids was confirmed from the dark field TEM micrographs. Present paper describes the experimental procedure and followed to attain severe plastic deformation through ECAP. Increase in hardness as well as refinement in the grain size after 5-passes have been discussed in light of extensive optical and TEM. The mechanisms of grain refinement to achieve nano-grained structure and strengthening accrued from the grain refinement through ECAP has been discussed.

Study of k and LiNbO<sub>3</sub> addition on the final properties of the relaxor pmn processed by powder blend

PMN ceramic relaxor has been investigated by several researchers and many aspects of this material, like powder morphology, phase decomposition, weight loss during sintering process, densification, between others, still are investigated. PMN powder preparation has been shown more efficient when synthesized by columbite route, however lead addition stage for the PMN powder synthesis remains problematical. Therefore, this work proposes a new association of methodologies, using columbite route and the hydroxide precipitation method. Through use of the powder mixture technique, which permitted to obtain good green and sintered densities, was possible to observe K + y Li + dopants reduce weight loss in sintering process and change significantly the dielectric properties. Addition of LiNbO 3 seeds in conformation stage, which react in a distinct way as a function of the particle size, promotes the formation of differenced grains in the ceramic bulk. Consequently, very different dielectrics properties from conventional PMN ceramic were obtained.

A study of morphology and texture of LPCVD germanium-silicon films

In this work, LPCVD Germanium-Silicon films were deposited on thermally oxidised silicon wafers using a horizontal LPCVD system, at a deposition temperature in the range between 430 and 480 °C and total pressure between 5 and 200 Pa. Pure GeH4 and SiH4 gases were used as precursors. Morphology and texture of the GexSi1-x (X=0.3-0.6) films were investigated versus deposition parameters. It has been shown that at the deposition temperature of 430 °C and total pressure of 20 Pa the grain size varied between 40 and 80 nm for a <100-nm thick poly-Ge0.6Si0.4 film, and the root-mean-square surface roughness did not exceed 2.5 nm. A decrease of the Germanium content from 60 to 40 atomic percent caused an increase of both the grain size and surface roughness due to nucleation matters. The polycrystalline layers mainly contained (110)- and (111)-oriented grains with its ratio depending on both deposition pressure and film thickness. The appearance of the big grains and roughening of the surface was also observed with increasing film thickness. Rising the total pressure above a certain level (100-200 Pa) caused an enhanced formation of the amorphous phase and appearance of randomly situated surface convexities. Reducing the total pressure below 10 Pa led to roughening of the surface, probably due to a dominance of (111)-oriented grains in the film bulk at such a low pressure.

Behavior Under High Pressure of Wheat Grains in Bulk

Behavior Under High Pressure of Wheat Grains in Bulk