Coarse Grinding Research Articles

Effect of grinding method and extent of pelleting of broiler diets on performance, feeding behaviour and digestive tract functionality

ABSTRACT 1. An experiment was carried out to examine if a heterogeneous diet consisting of pellets and coarse cereal particles would result in a similar feed intake to pelleted-only diets. It also considered whether coarser particles entering the gizzard would encourage the development of the gizzard and thus improve digestive tract functionality. Maize and wheat were hammer milled through a 3 mm screen after coarse grinding using either one of the two screens with a novel pattern. Three pellet-only diets were produced based on three grinding sizes. Additionally, four diets were produced by separating coarse cereal particles from moderately coarse particles by sieving either once or twice, pelleting the remainder and finally mixing these into a complete heterogeneous diet. 2. No difference in performance between birds fed the three pelleted-only diets was observed. However, heterogeneous diets resulted in a lower feed intake (FI) and weight gain (WG) than pelleted-only diets (p < 0.05). The dietary treatments neither affected the feed conversion ratio nor ileal digestibility of starch and protein (p > 0.05). As expected, feeding a heterogeneous diets increased (p < 0.05) the relative weight of the gizzard and its contents. Approximately 50% of the particles in the small intestine were between 0.15 mm and 0.36 mm in diameter, with more fine particles observed when the pelleted-only diets containing coarsely ground cereals were fed, confirming the capacity of the gizzard to finely grind feed. 3. Sieving of the diet remaining in the feeder during 4 h of feeding two of the heterogeneous diets showed that the particles > 2.8 mm disappeared first (p < 0.05), showing the birds’ preference for larger particles when offered heterogeneous diets. Although the birds were able to handle the coarse microstructure of the diets without any negative effects, the reduced performance in the case of heterogeneous diets might have been related to feed intake issues and particle selection, resulting in an imbalance in nutrient intake.

A distinctive material removal mechanism in the diamond grinding of (0001)-oriented single crystal gallium nitride and its implications in substrate manufacturing of brittle materials

Single crystal gallium nitride (GaN) substrates are highly demanded for fabricating advanced optoelectronic devices. It is thus essential to develop high efficiency machining technologies for this difficult-to-machine material, which in turn necessitates a thorough understanding of its deformation mechanism. In this study, the deformation and removal characteristics of (0001)-oriented single crystal GaN involved in diamond grinding were systematically investigated. The material removal exhibited a brittle mode when using relatively coarse diamond abrasives of 2000 in mesh size, while ductile removal was achieved when diamond abrasives of 6000 in mesh size were utilized. A novel peeling phenomenon was observed along (0001) lattice plane (c-plane) in the coarse grinding, as the crystal has a hexagonal crystal structure with c-planes serving as the preferable slip/cracking planes. Peeling observed in material removal agrees well with the findings that lateral planar defects were prone to initiate in nanoscratching in comparison to nanoindentation in the ductile regime, indicating that the effect of tangential grinding force is significant. The application of Molecular dynamics (MD) simulations, employing smaller indentation/scratching models, provided additional confirmation of the crucial role played by lateral force in initiating planar defects on c-planes. Furthermore, larger-scale MD scratching models substantiated the occurrence of peeling in the deformation process on c-plane, a finding corroborated by scratching experiments conducted in the brittle regime. Conversely, such peeling is absent on m- and a- planes. Complementary to the simulations, specifically designed grinding experiments were conducted to empirically demonstrate that peeling phenomena were intensified with elevated rotational wheel speeds. This enhancement was attributed to the increased tangential grinding force associated with higher speeds. These findings contribute to a comprehensive understanding of the intricate relationship between rotational wheel speed, tangential grinding force, and the observed peeling mechanisms in the context of single crystal GaN machining.

Optimization of crude rotenone oil extraction from birbira plant (Milletia ferruginea) seed by Soxhlet and maceration methods

The extraction of active compounds from plant materials is one of the most critical processes in the commercial development of natural products for pharmaceutical, herbicide or pesticide production. The focus of this study was extraction of crude rotenone oil (CRO) from Birbira plant (Milletia ferruginea) seed. The extraction was done using maceration anda Soxhlet extractor using organic solvents, such as ethanol, hexane, and chloroform. For the efficient extraction of crude rotenone oil from Birbira plant seed the effect of parameters, such as extraction method, solvent type, extraction time and size of crushed Birbira seed were investigated. Based on the experimental results obtained Soxhlet extraction method was more efficient (41.6% CRO yield) compared to the maceration extraction method (25.1 % CRO yield). The extraction results for both Soxhlet and maceration methods indicated that chloroform is more efficient compared to ethanol and hexane solvents. On the other hand, the effects of crashed seed size and extraction time on the % CRO yield were also investigated. The results showed that medium size (0.1–0.35 mm) for both Soxhlet and maceration extraction was the optimum size leading to the highest % CRO yield compared to fine and coarse ground seed size. The highest % CRO yield was obtained during 4 to 5 h of Soxhlet extraction and 25 to 30 h of maceration extraction method. Therefore, the Soxhlet extraction method is the fastest and efficient method for the extraction of CRO from plant materials. The characterization of Birbira seed powder and CRO was done with FTIR and Rheology test equipment. The FTIR result revealed that CRO is composed of aliphatic, olefin, polyphenol and alcohol functional groups, in which polyphenol functional groups are the most essential flavonoid components available in crude rotenone oil.

HYPREZ Wafering Solutions: A Novel Approach of SiC Wafering Solution

A novel approach for processing SiC wafers has been developed to grind then polish 150 and 200mm SiC wafers without lapping. The purpose of this work was to optimize the processing of SiC wafers sliced from boules to finished epi-ready wafers by grinding and chemical-mechanical polishing (CMP). Diamond vitrified wheels were used for coarse and fine grinding to correct the irregular shape of SiC wafers before reducing surface roughness by CMP. 4H-SiC wafers were sliced by diamond embedded/slurry wire saw and laser split techniques. Incoming wafer condition was seen to affect coarse grinding wheel performance depending on incoming surface roughness and shape. Wheel characteristics, including abrasive size, abrasive concentration, and bond structure, were adjusted to improve grinding efficiency based on incoming conditions. Coarse grinding wheels were able to reduce wafer total thickness variation to 3-5um and average surface roughness to 20-30nm (Ra). Fine grinding wheels were optimized to reduce total thickness variation (TTV) below 2um and surface roughness to 1-2nm Ra and peak-to-valley height of 20-30nm (Rt). Coarse and fine wafering time was less than 30 minutes total to remove 50 microns on both Si and C-face per wafer. Surface damage from grinding was removed after one hour of polishing each wafer by CMP, achieving surface roughness of 0.4nm Ra and 5-7nm Rt. The benefit of optimizing coarse and fine grinding of 150 and 200mm SiC wafers is demonstrated by producing flat wafers, which reduced overall processing time to prepare an epi-ready condition by CMP.

Study of Prefabricated Crack Propagation on Monocrystalline Silicon Surfaces for Grinding Damage Analysis.

Crack generation and propagation are critical aspects of grinding processes for hard and brittle materials. Despite extensive research, the impact of residual cracks from coarse grinding on the cracks generated during fine grinding remains unexplored. This study aims to bridge this gap by examining the propagation law of existing cracks under indentation using the extended finite element method. The results reveal that prefabricated cracks with depths less than the crack depth produced on an undamaged surface tend to extend further without surpassing the latter. Conversely, deeper prefabricated cracks do not exhibit significant expansion. A novel method combining indentation and prefabricated cracks with fracture strength tests is proposed to determine crack propagation. Silicon wafers with varying damaged surfaces are analyzed, and changes in fracture strength, measured by the ball-on-ring method, are utilized to determine crack propagation. The experimental results confirm the proposed crack evolution law, validated by damage assessments across different grinding processes, which is suitable for crack damage. The findings demonstrate that residual cracks from coarse grinding are negligible in predicting the maximum crack depth during fine grinding. This research provides a crucial foundation for optimizing the wafer thinning process in 3D stacked chip manufacturing, establishing that changes in fracture strength are a reliable indicator of crack propagation feasibility.

Shrimp Digestive Bacteria Performance for Shrimp Waste Chitin Extraction

Generally, chitin is isolated chemically. An environmentally friendly alternative to chitin extraction is enzymatic extraction. The research aims to determine the effectiveness and optimum conditions for enzymatic chitin extraction of shrimp waste (heads, shells, and tails) using lactic acid bacteria (LAB) and proteolytic bacteria from the shrimp's digestive tract (faeces and intestines). The research stages were isolation, enrichment, and determining shrimp digestion's bacterial colonies, microscopic identification of shrimp digestive bacteria, and determining the effectiveness and optimal conditions for shrimp waste's chitin isolation. Aerobic and Anaerobic Total Plate Count (TPC), LAB, and proteolytic bacteria from shrimp's digestive tract per gram of sample were respectively 5.52 and 5.59 log CFU; 4.76 and 4.56 log CFU; 6.46 and 6.20 log CFU. Microscopic morphology shows that LAB and proteolytic bacteria of shrimp digestive are gram-positive as cocci or rods. The deproteinization value of shrimp waste reached 31%, especially for treatment with a pH of 5.0–7.0 (during proteolytic bacteria fermentation) and pre-treatment of boiling, drying and coarse grinding of shrimp waste (PP2) before extraction. However, the demineralization value of shrimp waste is only 4.5% (PP1) and 3% (PP2), with LAB as the primary fermentation agent because proteolytic bacteria have been unable to reduce the mineral content in shrimp waste further.

Sensory assessment of Gayo Arabica coffee using various cold brew tools

Currently, there is a rapid increase in the cold brew method for coffee, favored by connoisseurs, especially Arabica coffee. This technique uses room temperature water, usually between 4–25°C, and is carried out through the stage of immersing coffee grounds with a coarse grind size in water at an extraction time of 8–24 hours. Therefore, this research aims to conduct a sensory assessment of Gayo Arabica coffee with a cold brew approach to a product with the best taste through a decision-making system using the Fuzzy Simple Additive Weighting (FSAW) method. A total of 5 samples of Gayo Arabica coffee were postharvest processed using the Honey method, which was brewed with various cold brew tools such as Asobu, French Press, Tygo Breeze, Toddy, and Eva Solo. The results showed that the level of product acceptance was different for each alternative product based on various cold brewing tools. The highest ratings of various cold drink alternatives were Asobu 0.974 (rank 1), Toddy 0.913 (rank 2), TygoBreeze 0.872 (rank 3), French Press 0.847 (rank 4), and Eva Solo 0.784 (rank 5). This showed that the FSAW method can easily be used to determine the best alternative for each Gayo Arabica coffee brewing with various cold brew tools.

Scaling use of the rust fungus Puccinia punctiformis for biological control of Canada thistle (Cirsium arvense (L.) Scop.): First report on a U.S. statewide effort

Canada thistle (Cirsium arvense (L.) Scop., CT) is one of the worst weeds threatening temperate regions of the world. A host-specific rust fungus, Puccinia punctiformis (F. Strauss) Rohl., is known to cause systemic disease of CT, ultimately killing individuals and reducing stand densities. In 2013, it was demonstrated that fall inoculation of rosettes with coarsely ground leaves bearing P. punctiformis telia can successfully initiate epiphytotics. In the same year, a cooperative project between the Colorado Department of Agriculture and United States Department of Agriculture was initiated, in which CT patches across the state of Colorado (USA) were inoculated and tracked over subsequent years for changes in stem density. Here, we report our findings from 8 years (2014–2021) of monitoring effort. At most sites (N = 87), CT stem densities declined, from a mean (±SE) of 87.9 (±6.5) stems to 44.7 (±4.2). These declines however were spatially-autocorrelated, and likely attributable to local growing conditions, as mean annual daily maximum temperature and standard deviation of elevation, as well as climatic conditions around the times of both treatment and monitoring, were found to be important predictors of CT decline. Further, we observed that the amount of inoculum deployed, timing since last release, and method in which it was spread locally at a site were also associated with the magnitude of CT stem decline. These results are indicative of the value of P. punctiformis as a CT biological control agent.

The effect of increasing the level of oat hulls, extent of grinding and their interaction on the performance, gizzard characteristics and gut health of broiler chickens fed oat-based pelleted diets

The effect of ratio of oats with hulls (OWH) to dehulled oats (DO), extent of grinding, and their interaction on the performance, gizzard characteristics and intestinal health of broilers chickens were studied in this experiment. A total of 2860 one-day-old male broilers were allocated to 130 floor pens bedded with wood shavings and fed a starter diet until day 10. On day 11, the birds were randomly distributed among ten dietary treatments (13 replicates each), consisting of five oat-based pelleted diets with different proportion of OWH and DO, and with main ingredients either finely- (2 mm) or coarsely-ground (6 mm). Half of a batch of oats was thoroughly dehulled and half kept as is. The content of hulls (OH) in the DO and OWH was 1 and 224 g/kg, respectively. Using different OWH:DO ratios, the diets were formulated to contain 0, 29.5, 65.0, 96.0 and 114.0 g/kg OH. The ratio of ingredients to DO, and apparent metabolisable energy to protein (AME:CP) were kept constant for all diets. Birds and feed were weighed on day 11 and at termination on day 32. Increasing OH level did not affect weight gain (WG) from 11 to 32 days, but increased FCR linearly (P < 0.001). Although FI was not affected by the extent of grinding, FCR was significantly improved with fine grinding. Birds fed diets with highest OH level had a lower AME:WG compared to those given diets with DO only. Coarse grinding significantly increased gizzard dry matter (DM) weight which also increased linearly (P < 0.001) with increasing OH level. Coarse grinding as well as increasing OH level significantly improved gizzard and pancreas relative weights and decreased gizzard contents pH. Excreta DM contents and litter score were significantly improved with increasing OH level. Coarse grinding tended to (P = 0.069) reduce total eubacteria density in the ileum only at the highest OH level and tended to (P = 0.080) reduce Lactobacillus spp. density compared to fine grinding. Increasing OH level had no impact on caecal short chain fatty acids or lactic acid production, but it decreased indole concentration linearly (P = 0.026). Coarse grinding tended to increase (P = 0.053) caecal propionic acid production. Importantly, broiler chickens were able to handle an OWH-based diet and still maintained a similar WG compared to diets with DO only. A larger gizzard holding capacity and a faster passage of excess OH may explain the ability to increase FI in response to high OH dilution. The positive effect of OH on performance was more obvious when finely ground, but coarse components in the diets induce beneficial effects on intestinal microbiota.

Forage sources in total mixed rations early in life influence performance, metabolites, and behavior of dairy calves

The objective of this study was to evaluate effects of forage inclusion and sources on performance, metabolism, and feeding behavior of dairy calves. Forty-eight Holstein calves were blocked and randomly assigned to 1 of 4 dietary treatments according to sex, and body weight (BW) at 28 d of life to determine the effects of feeding forage sources (ensiled and dry), with different quality on performance, metabolites, and behavior. Treatments consisted of a no-forage coarsely ground starter (CON); or total mixed ration containing 7.5% on DM basis of Tifton hay of either medium quality (MH) or low quality (LH); or 10% on DM basis of corn silage (CS). During the first 28 d of life, all calves received 3 L of whole milk twice daily, a commercial pelleted starter and no forage, and water ad libitum. After that, the solid diet was changed to the respective dietary treatments. Calves were gradually weaned from 52 to 56 d of age, and followed for 14 d post-weaning. Individual solid feed and milk intakes were recorded daily, and BW and metabolic indicators of intermediate metabolism were recorded weekly. Behavior was recorded, and the analysis was conducted on wk 7 (preweaning) and 10 (post-weaning). Solid feed intake increased at wk 7 and 8 when MH, LH, and CS were included in TMR; the same results were observed post-weaning. The diets did not affect the average daily gain and body weight, but the feed efficiency increased with the CON diet. The β-hydroxybutyrate concentration was greater in calves receiving TMR containing forage than CON diet. Furthermore, calves supplemented with forage had a greater rumination time. In conclusion, all forage sources included in the TMR showed feed intake and behavior benefits, reinforcing the need for fiber from forage in pre- and post-weaning diets.

Эффективность применения ферментных препаратов при водной экстракции фенольных веществ из листьев зеленого чая

A study was conducted to obtain green tea extract using enzyme preparations of various substrate specificities. In the experiments, we used crushed green tea leaves of the Greenfield Flying Dragon variety with different degrees of grinding: coarse grinding, which included particles with a size of 56.4% passing through a Ø 1 mm sieve, and fine grinding, which included particles with a size of 100% passing through a Ø 1 mm sieve and 75% passing through a Ø 0.25 mm sieve. It was found that the yield of phenolic substances from coarse and fine grinding differs slightly but depends on the hydromodule. To obtain aqueous extracts of green tea with a high content of phenolic substances, it is recommended to use a hydro modulus of 1:20. To assess the effectiveness of enzyme preparations on the yield of phenolic substances, enzyme preparations of different substrate specificity were used: cellulolytic action – CelloLux-A, Viscoferm; proteolytic action – Vegazym M, Fructozym P6-L, Fructozym BE, Fructozym MA, Fructozym Press, Pectinex Ultro; proteolytic action – Protosubtilin G3x, Destizym Protocid Extra. The effectiveness of the enzyme preparation was assessed relative to the control sample (without adding the enzyme preparation) and expressed in %. As a result, it was found that of all the analyzed enzyme preparations, CelloLux-A has the greatest effect on the yield of phenolic substances and increases the yield of phenolic substances by 40–96%. To determine the optimal modes for the extraction of phenolic substances: temperature, duration, and dose of application of CelloLux-A, the method used a full factorial experiment (FFE 23) and the "steep" ascent method. As a result, a mode for obtaining green tea extract was determined that ensures the concentration of phenolic substances in the extract in the amount of 988 mg/dm3: temperature 60°C, duration – 1 hour, dose of CelloLux-A – 0.09% by weight of green tea leaves. Green tea leaf extract can be used by many sectors of the food industry as a source of biologically active substances in the production of functional foods and drinks.

The Bran and Grain Grinding Level Affect the Tensile Characteristics of Bioplastics Derived from Wholegrain Wheat Flours.

The mechanical performance of thermoplastic bulk samples obtained by plasticizing wheat flours differing in grain hardness, alveographic parameters, absence or presence of bran, and grinding level was assessed. Grains of four bread wheat (Triticum aestivum L.) cultivars (Altamira, Aubusson, Blasco, and Bologna) were milled with the aim of producing single-cultivar refined flour (R), or wholegrain flour with fine (F) or coarse (C) grinding. The flours were plasticized, injection molded and tested for tensile properties. The results confirmed that the presence of bran increased the strength (σ) and reduced the elongation at break (ε) of thermoplastics obtained from the flours of each cultivar. The grinding level had an effect, since σ was higher and ε was lower in F than in C samples. SEM analysis of samples revealed that the bran and its texture affected the exposure of starch granules to plasticizer. Composting experiments also revealed that the formulations are able to disintegrate within 21 days with a mass loss rate higher in plastics from F than C flours, while germination tests carried out with cress seeds indicated that it takes two months before the compost loses its phytotoxic effects. Overall, the refining and bran particle size of wheat flours, besides their gluten composition and baking properties, represent novel choice factors to be considered when tailoring the manufacturing of plastic materials for selected requirements and uses.

Effect of different surface and heat treatments on the surface roughness, crystallography, and phase composition of high translucency zirconia for monolithic restorations

Statement of problemHigh translucency zirconia (HTZ) has gained popularity as an esthetic computer-aided design and computer-aided manufacturing (CAD-CAM) material for monolithic restorations. A detailed comparison between different common surface and heat treatments with a non-treated HTZ control to explain the behavior of the material under stress is lacking. PurposeThe purpose of this in vitro study was to evaluate the effect of different surface and heat treatments on the surface roughness parameters (SRPs), topography, crystallography, and phase composition of HTZ used for monolithic restorations. Material and methodsNinety Ø11.9×1.18-mm HTZ disks (Prettau Anterior) were milled, sintered, and distributed into 9 groups (n=10); 8 experimental (coarse diamond grinding GC, fine diamond grinding GF, fine diamond grinding and 3-step polishing kit GF+P1, fine diamond grinding and 3-step polishing kit and diamond paste GF+P1+DP, fine diamond grinding and 2-step polishing kit GF+P2, fine diamond grinding and GF+Gl, fine diamond grinding and 3-step polishing and glazing GF+P1+Gl, airborne-particle abrasion with 50-µm alumina), and a control group (C, as-sintered). SRPs (AveSa, AveSv, AveSz) and 3-dimensional (3D) images were obtained using a noncontact 3D-optic-profilometer. The crystal structure was determined with scanning electron microscopy. Phase composition was analyzed by X-ray diffraction (XRD). Surface roughness parameters data were statistically analyzed by 1-way ANOVA and the Tukey HSD test (α=.05). ResultsThe applied surface and heat treatment resulted in significantly different SRP mean values (P<.001) with different topographies. GC had the highest AveSa, AveSv, and AveSz mean values (0.95, 8.8, 17.4 µm, respectively) with significant microcracks. GF had significantly lower SRP with finer microcracks. GF+P1 had a significantly smoother surface, but GF+P2 resulted in SRP comparable with the GF group. GF+P1+DP had the smoothest homogenous surface (mean Sa: 0.08 µm). GF+P1 and GF+GL were equally effective, while GF+P1+GL was not superior. Airborne-particle abrasion produced a low Sa mean value (0.11 µm) with relatively high Sv and Sz mean values (5.9, 9.2 µm, respectively) and microcracks. A monoclinic phase was detected in all groups. All experimental groups had broadened XRD-peaks with lower intensity, suggesting the presence of the rhombohedral phase. ConclusionsThe different surface and heat treatments altered the HTZ crystals and their surface roughness with distinct topographies. Cubic crystal changes take place under stress as shown by the scanning electron microscope and the XRD diffraction pattern and may transform to the rhombohedral phase.

Modeling of the Aqueous Solubility of N-butyl-N-methyl-1-phenylpyrrolo[1,2-a] pyrazine-3-carboxamide: From Micronization to Creation of Amorphous-Crystalline Composites with a Polymer.

N-butyl-N-methyl-1-phenylpyrrole[1,2-a] pyrazine-3-carboxamide (GML-3) is a potential candidate for combination drug therapy due to its anxiolytic and antidepressant activity. The anxiolytic activity of GML-3 is comparable to diazepam. The antidepressant activity of GML-3 is comparable to amitriptyline. GML-3 is an 18 kDa mitochondrial translocator protein (TSPO) ligand and is devoid of most of the side effects of diazepam, which makes the research on the creation of drugs based on it promising. However, its low water solubility and tendency to agglomerate prevented its release. This research aimed to study the effect of dry grinding, the rapid expansion of a supercritical solution (RESS), and the eutectic mixture (composite) of GML-3 with polyvinylpyrrolidone (PVP) on the particle size, dissolution rate, and lattice retention of GML-3. The use of supercritical CO2 in the RESS method was promising in terms of particle size reduction, resulting in a reduction in the particle size of GML-3 to 20-40 nm with a 430-fold increase in dissolution rate. However, in addition to particle size reduction after RESS, GML-3 began to show signs of a polymorphism phenomenon, which was also studied in this article. It was found that coarse grinding reduced particle size by a factor of 2 but did not significantly affect solubility or crystal structure. Co-milling with the polymer made it possible to level the effect of the appearance of a residual electrostatic charge on the particles, as in the case of grinding, and the increased solubility in the resulting mechanical mixtures of GML-3 with the polymer may also indicate the dissolving properties of polymers (an increase in 400-800 times). The best result in terms of GML-3 solubility was demonstrated by the resulting GML-3:PVP composite at a ratio of 1:4, which made it possible to achieve a solubility of about 80% active pharmaceutical ingredient (API) within an hour with an increase in the dissolution rate by 1600 times. Thus, the creation of composites is the most effective method for improving the solubility of GML-3, superior to micronization.

Building a model of the impact grinding mechanism in a tumbling mill based on data visualization

A mathematical model was built based on data visualization for the impact grinding mechanism in a tumbling mill, which is mainly implemented during coarse grinding. The determination of impulse interaction parameters is problematic due to the difficulty of modeling and the complexity of hardware analysis of the behavior of intramill loading. Conceptually, it was envisaged to identify the relative dynamic parameters of the impact action as components of the model, which are criteria for the similarity of the loading movement and the grinding process. Impact power was taken as an analog of grinding performance. The initial characteristic of the impact was considered to be the averaged vertical component of the speed of loading movement in the flight zone at the boundary of contact with the shear layer. The formalization of the model revealed the effect on the performance of the mass fraction of the flight zone and the reversibility of loading. The method of numerical modeling was applied, based on experimental visualization of the behavior of granular loading in the cross section of a rotating chamber. The influence of the rotation speed on the performance at a chamber filling degree of 0.45 and a relative particle size of a milling load of 0.0104 was estimated by experimental simulation. The maximum productivity value was found at the relative speed of rotation ψω=1–1.05. A rational condition for impact grinding at ψω=0.75–0.9 has been established. The test proved the effectiveness of using visualization to evaluate dynamic loading interaction analogs. Verification of modeling results was implemented by comparison with the data of the technical standard. The use of similarity criteria unifies approaches to modeling different mechanisms of destruction. The model built makes it possible to predict the rational parameters of the grinding processes by impact, crushing, and abrasion

Analysis of the energy laws of material destruction

The number of parameters that determine the process of destruction of materials in the crushing chamber is significant and difficult to describe by known mathematical laws. Most of the theories that describe the energy consumption of the destruction process are based on empirical indicators and are not supported by the theoretical foundations of the process. The paper provides an analysis of the latest research in the field of material destruction processes, on the basis of which it was established that modern methods of determining the energy of material destruction differ significantly from each other, are based on different energy hypotheses, both according to accepted assumptions and according to the obtained results. Thus, the lack of a generally accepted model of the grinding process and a single method of determining the energy consumption of the process of destruction of materials by crushing machines is the problem that needs to be solved. For this purpose, an analysis of the main classical laws of destruction of materials in the crushing chamber was carried out. Almost all classical laws are described by the use of proportionality coefficients, which take into account the physical properties of the material, friction costs in the machine nodes, heat losses, the amount of material in the crushing chamber and other parameters that affect the destruction process. This leads to the difficulty of determining the influence of individual parameters on the destruction process, in addition, the coefficients themselves do not have a calculation method and in most cases are determined experimentally. Bond's law has the largest number of variations. In which the work index parameter is used as a proportionality factor. However, the parameter of the Bond work index has a wide range of changes, as well as a large number of methods for its calculation. In general, the dependence itself describes well the processes between the zones of fine crushing and coarse grinding. In the work, the limits of the change of the proportionality coefficients for various energy laws were established for the corresponding destruction conditions. The wide limits of the change of the coefficients testify to the significant stochasticity of the process itself, and do not allow a true description of the picture of destruction. One of the options for the intensification of the destruction process is the application of a shock load. The paper considers the dependence for determining the energy consumption during the dynamic destruction of rocks, which makes it possible to assess the advantages and disadvantages of static destruction. The main parameters that have an impact on dynamic destruction are the speed of load application and the geometry of the surface of the working tool. Based on the analysis, it was established that a large number of parameters that influence the crushing process of machines for the production of building materials greatly complicate the creation of a single theory of destruction at this stage of human development. The further development of research on destruction processes in crushing machines is seen in the creation of a stochastic model for describing the kinetics of the destruction process, which will take into account the peculiarities of the destruction process at the micro and macro levels.

Effects of corn grain processing and protein source on calf performance, rumen fermentation, and blood metabolites

The objective of this study was to investigate the effects of the interaction between corn grain processing and protein source on feed intake, growth performance, rumen fermentation, and blood metabolites of dairy calves. Seventy-two 3-day-old Holstein calves with an initial weight of 39.1 ± 3.24 kg were randomly assigned (n = 12 calves (6 male and 6 female) per treatment) to a 2 × 3 factorial arrangement of treatments with the factors of physical form of the corn grain [coarsely ground (CG) and steam-flaked (SF)] and protein type [canola meal (CAN), canola meal + soybean meal (CASY), and soybean meal (SOY)] were assigned. The study showed a significant correlation between corn grain processing method and protein source on calf performance, including starter feed intake, total dry matter intake (DMI), body weight, average daily gain (ADG), and feed efficiency (FE). The CG-CAN and SF-SOY treatments resulted in the highest feed intake and DMI in the post-weaning and total period, respectively. Interestingly, corn processing did not affect feed intake, ADG, and FE, but the highest ADG was observed at SF-SOY and CG-CAN. In addition, the interaction between corn processing method and protein source improved FE in calves fed CG-CAN and SF-SOY during the preweaning period and throughout the period. Although skeletal growth parameters were unchanged, calves fed SOY and CASY had greater body length and withers height than calves fed CAN during the preweaning period. Rumen fermentation parameters were also not affected by the treatments, except that calves fed CAN had a higher molar proportion of acetate than calves fed SOY and CASY. Corn grain processing and protein source did not affect glucose, blood urea nitrogen (BUN), or β-hydroxybutyrate (BHB) concentrations, except for the highest blood glucose level observed in the CAN treatment and the highest BUN level observed in the preweaned calves fed SOY. However, a two-way interaction was observed for BHB concentration, suggesting that ground corn grain resulted in higher BHB concentration during the preweaning and postweaning periods than steam-flaked corn. In summary, it is recommended to incorporate canola meal with ground corn or soybean meal with steam-flaked corn in calf starters to enhance calf growth.

Effect of Particle Size of Silage of Flint Corn Grain on Dairy Cows Fed Tropical Pasture: Performance, Intake, Ruminal Fermentation, and Digestibility.

The particle size (PS) of reconstituted corn (REC) can affect the grinding rate and starch digestibility in dairy cows. We evaluated the effect of the PS of REC ensiled for 40 days on the pasture dry matter intake (DMI), lactation performance, total tract digestibility, and ruminal fermentation of grazing dairy cows. The treatments were coarse REC (CO, 1694 µm), fine REC (FI, 1364 µm), or finely ground (GC, 366 µm) flint corn (68% vitreousness) at 29.6 ± 1.4% of diet DM (mean ± SD). Eighteen dairy cows (mean milk yield 21.3 kg/d) were split into three groups by production level and were assigned within each group to a sequence of treatments in 3 × 3 Latin squares of 21-day periods. Cows were individually fed a constant amount of whole-plant corn silage 3 ×/d (2.7 kg DM/d) and corn treatments and soybean meal according to their group. There was no significant interaction between treatment and the production level. Cows fed FI had a lower DMI (16.7 vs. 18.1 kg/d) than those fed GC, and both did not differ from CO (17.7 kg/d). There was no treatment effect on milk yield (mean: 19.2 kg/d). Cows fed CO had the lowest total tract digestibility of starch (86.3 vs. 92.3% of intake) and the highest fecal starch concentration (7.0 vs. 4.0% of DM). The NDF digestibility was lower for GC-fed cows than CO- and FI-fed cows. Plasma glucose was higher in cows fed FI and CO (75.0 mg/dL) than those fed GC (70.8 mg/dL). Ruminal volatile fatty acids and the pH did not differ. Fine grinding of REC increased the feed efficiency relative to CO and GC. Coarse grinding of REC ensiled for 40 days reduced the total tract starch digestibility relative to FI and GC.

Processing methods of flint corn and protein supplement in forage-free diets for feedlot lambs.

Diets without forage increase the productivity in less time and favor greater practicality and better quality carcass. The corn grain is mostly used associated with pellets but processing these ingredients can bring benefits. The present study evaluated the effect of diets without forage based on whole or coarse ground corn associated with pelleted or ground protein supplement on performance, eating behavior, carcass characteristics, and ruminal morphology of feedlot lambs. Thirty-five Dorper × Santa Inês lambs were used, with 23.85 ± 3.88 kg of initial body weight and 88 ± 9 days old. The experimental design was in a randomized complete block, defined by body weight and age. The experimental diets were control (CONT), containing 90% of concentrate and 10% of forage (coastcross hay), and 4 diets without forage: WC+P, 70% whole flint corn and 30% pelleted protein supplement; WC+G, 70% whole flint corn and 30% ground protein supplement; GC+P, 70% ground flint corn and 30% pelleted protein supplement; and GC+G, 70% ground flint corn and 30% ground protein supplement. There was an interaction between treatments and experimental periods for DMI in kg/day (P = 0.01) and g/kg of BW0.75 (P < 0.01; Table 3). For the DMI in kg/day, no significant differences were observed between the treatments in any of the experimental periods. However, for DMI expressed in g/kg of BW0.75, the animals fed WC+P had lower DMI than the animals on the CONT (P < 0.01) only in the first period. The ADG, FBW, and FE were not affected by the treatments. Compared to CONT, forage-free diets decreased ingestion time (min/day) and rumination and chewing (min/day and min/g of dry matter). There was no effect of treatments for any of the carcass traits evaluated. The diets did not cause lesions suggestive of ruminitis. Forage-free diets containing whole or ground corn associated with pelleted or ground protein supplement can be used successfully for feedlot lambs; they provide proper performance and carcass characteristics, without harming the animal's health.

A Fast Ground Segmentation Method of LiDAR Point Cloud From Coarse-to-Fine

Light detection and ranging (LiDAR) has become an indispensable sensor for autonomous vehicles due to its unique properties. Segmentation of raw point cloud is a fundamental step in the perception processing pipeline, which is critical to the safe driving of autonomous vehicles. However, some existing methods are prone to over-segmentation, insufficient segmentation, or poor real-time performance in the process of point cloud segmentation. Therefore, we propose a coarse-to-fine segmentation strategy to balance segmentation accuracy and speed. The ground segmentation includes applying robust locally weighted regression (RLWR) to the nonuniformly divided bins of polar grids in concentric model to achieve coarse ground segmentation. The processing results are mapped to a range image, and the improved range image convolution method is used to refine the ground segmentation. We evaluate the proposed method on two public datasets, and the precision, recall, and harmonic mean of the ground segmentation are all above 93%, which is sufficient to demonstrate the robustness of our method. Using the segmentation strategy from coarse to fine, the average processing time per frame of the SemanticKITTI dataset and the Nagoya dataset are 39.49 and 42.63 ms, respectively, with an average of 41.06 ms, which can meet the real-time requirements of autonomous driving.