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Granite edge finishing through grinding is a common process in the granite processing industry, crucial for achieving the final desired shape and edge quality of products. This study focuses on the granite industry, specifically delving into the significance of grinding and polishing for improving aesthetics and extending material longevity. The experimental design entails a comprehensive factorial experiment plan involving two workpiece materials (white and black granite samples) and two cutting tool edge shapes (chamfer and concave), each with two grit sizes: G150 and G600. The cutting conditions varied and consisted of variations in spindle speeds (1500, 2500, 3500 rpm), feed rates (500, 1000, 1500 mm/min), and lubrication modes (wet/dry). The results uncover intricate relationships among these parameters and part quality, underscoring the pivotal role of tool geometry in achieving superior surface finishes and in controlling the cutting forces. These findings contribute to a nuanced understanding of the dynamic interplay between tool characteristics, material properties, and machining conditions within the granite industry.

Flavonoids are phenolic compounds involved in defense mechanisms against black pod disease (BPD). Crossing between Forastero and Trinitario-resistant cocoa genotypes usually produce resistant progenies with high contents of bioactive components. This study aims at analyzing flavan-3-ol and flavonol content in the defense against P. megakarya in T. cacao genotypes for their potential selection as markers of partial resistance to BPD. Assessment of necrosis development and biochemical markers of stress (total polyphenols (TPP), total flavonoids (TF), and condensed tannins (CT)) through spectrophotometric methods of 19 genotypes identified eight hybrids that contained higher amounts (P˂0.05) of bioactive components than the better parent T79/467. The necrosis length revealed to be negatively correlated with metabolite concentrations (P < 0.05). Flavan-3-ols and flavonols were analyzed by normal phase (NP) and reverse phase (RP) HPLC–DAD-ESI (-)-MS/MS. Among the best genotypes, flavan-3-ol monomers (( +)-catechin, (-)-epicatechin), derived procyanidins (especially B2 and four of its isomers, C1, and one pentamer), and flavonols (quercetin, quercetin-3-O-arabinoside, quercetin-3-O-glucoside, quercetin-3-O-rhamnoglucoside, and one isomer) were evidenced both in healthy and infected leaves. Analyzed metabolites increase following infection, but infection does not trigger the synthesis of new compounds. The order of accumulation of biomolecules is as follows: (-)-epicatechin (196%), procyanidin C1 (184%), pentamers (140%), procyanidin B2 (135%), quercetin (80%), quercetin derivatives (57–69%), and ( +)-catechin (57%). Yet their accumulation after infection revealed to be genotype-dependent. This breeding approach is designed to select partial resistant cocoa genotypes against BPD evidenced useful biomarkers in hybrids with high flavonoid content.

Particles emitted during manufacturing processes such as polishing can represent a serious danger for the environment and for occupational safety. The formation mechanisms responsible for these dust emissions include chip formation, friction at the tool/workpiece and chip/tool interfaces, shearing and cutting. These mechanisms thus depend on workpiece and tool properties, as well as the polishing conditions. In the case of granite polishing, particle emissions during polishing can contain chemical compounds such as silica, which represent harmful health risks for the worker. It is therefore important to characterize the particles emitted and to search for possible interactions between the particles (size and composition) and the machining conditions in order to find ways of reducing emissions at the source. In this study, an investigation was undertaken to characterize the particles emitted during granite polishing as a function of polishing conditions, type of granite, and abrasive grit sizes used. Scanning electron microscopy (SEM) was employed for particle mor- phology characterization and particle grain size and chemical composition were evaluated using X-ray diffraction (XRD) and energy dispersive X-ray (EDX) techniques, respectively. Results show that the influence of polishing speed and feed rate on particle emission depends mainly on the granite type used, providing useful information for controlling the polishing procedure, and thereby dust emission.

Edge-finishing of granites by grinding is a process frequently used in the granite processing industry to generate the final desired shape and edge quality of products. However, this process releases significant amounts of fine and ultrafine particles (FPs and UFPs) containing crystalline silica. When inhaled, this dust can cause silicosis disease and threaten the health and safety of workers. The purpose of this study is to optimize the process by decreasing the concentrations of dust generated while also maintaining the required surface finish. Experimental tests were planned and performed on granite samples using a full factorial design. Two cutting tool edge shapes were studied (chamfer and concave) using G150 and G600 grit size tools, at various spindle speeds (1500, 2500, 3500 rpm), feed rates (500, 1000, 1500 mm/min) and lubrication flow rates (20, 40, 60 mL/min). The findings show that the particle emissions as well as the surface finish depend on the tool shape, its grit size, and the machining and lubrication parameters used. Higher MQL flow rates led to better finished surface quality and lower concentrations of fine dust. Polishing with flood lubrication reduces the maximum number concentration of FPs corresponding to particles smaller than 1 µm diameter by about 85% as compared to dry polishing and produced the best surface finish. Polishing with lubrication in MQL mode at 60 mL/min led to the production of part with Ra-value comparable with that obtained in flood lubrication condition