The size and distribution of abrasive particles have a significant influence on the effectiveness of the cutting process by the high-speed abrasive water jet (AWJ). The paper deal with the abrasive materials disintegration intensity in AWJ cutting during the creation of the abrasive jet. An evaluation of the abrasive materials grabbed after forming in the cutting head was carried out and its grain distribution was evaluated. Used here the arithmetic, geometric and logarithmic method of moments and Folk and Ward method. The influence of abrasive concentration of abrasive materials as alluvial garnet, recycled garnet, corundum, and olivine on grain distribution was studied. A recovery analysis was also carried out and the recycling coefficient for each tested abrasive material was determined.

Corundum-rich (up to 55 vol.%) felsic dykes formed by albite, ±K-feldspar, ±hercynite and ±biotite-siderophyllite cut the lower crustal rocks exposed in the Ivrea-Verbano Zone (NW Italy). Zircon is an abundant accessory mineral and its investigation through LA-ICP-(MC)MS has allowed to directly constrain the timing of emplacement, as well as petrology and geochemistry of parental melts. Zircons are characterised by very large concentration in REE, Th, U, Nb and Ta, and negative Eu anomaly. U–Pb analysis points to Norian emplacement ages (223±7 Ma and 224±6 Ma), whereas large positive εHf(t) values (+13 on average) indicate a derivation from depleted to mildly enriched mantle source. The mantle signature and the corundum oversaturation were preserved thanks to limited crustal contamination of the host, HT refractory granulites and mafic intrusives. According to the geochemical data and to the evidence of the development of violent explosions into the conduits, it is proposed that dykes segregated from peraluminous melts produced by exsolution processes affecting volatile-rich differentiates during alkaline magmatism. This work provides robust evidence about the transition of the geochemical affinity of Southern Alps magmatism from orogenic-like to anorogenic during Norian, linked to a regional uprising of the asthenosphere and change of tectonic regime.

The possibility of making precious stones from radioactive waste is being considered. Vitrified and cemented radioactive waste (RW) is considered as an artificial rock belonging to aluminosilicates and calcites. Two methods are proposed for the manufacture of radioactive gemstones from RW and their subsequent storage with the possibility of sale, resale, inheritance, and so on. That is, RW is considered as real estate in which capital can be invested. After decontamination in hundreds and thousands of years, it will be of scientific, historical, jewelry interest.

Nonporous corundum powder, known as an abrasive material in the industry, was functionalized covalently with protein binders to isolate and enrich specific proteins from complex matrices. The materials based on corundum were characterized by TEM, ESEM, BET, DLS, and zeta potential measurements. The strong Al-O-P bonds between the corundum surface and amino phosphonic acids are used to introduce functional groups for further conjugations. The common crosslinker glutaraldehyde was compared with a hyperbranched polyglycerol (PG) of around 10 kDa. The latter is oxidized with periodate to generate aldehyde groups that can covalently react with the amines of the surface and the amino groups from the protein via a reductive amination process. The amount of bound protein was quantified via aromatic amino acid analysis (AAAA). This work shows that oxidized polyglycerol can be used as an alternative to glutaraldehyde. With polyglycerol, more of the model protein bovine serum albumin (BSA) could be attached to the surface under the same conditions, and lower nonspecific binding (NSB) was observed. As a proof of concept, IgG was extracted with protein A from crude human plasma. The purity of the product was examined by SDS-PAGE. A binding capacity of 1.8 mg IgG per g of corundum powder was achieved. The advantages of corundum are the very low price, extremely high physical and chemical stability, pressure resistance, favorable binding kinetics, and flexible application.

Immobilized metal affinity chromatography (IMAC) is a popular and valuable method for the affinity purification of polyhistidine-tagged recombinant proteins. However, it often shows practical limitations, which might require cumbersome optimizations, additional polishing, and enrichment steps. Here, we present functionalized corundum particles for the efficient, economical, and fast purification of recombinant proteins in a column-free format. The corundum surface is first derivatized with the amino silane APTES, then EDTA dianhydride, and subsequently loaded with nickel ions. The Kaiser test, well-known in solid-phase peptide synthesis, was used to monitor amino silanization and the reaction with EDTA dianhydride. In addition, ICP-MS was performed to quantify the metal-binding capacity. His-tagged protein A/G (PAG), mixed with bovine serum albumin (BSA), was used as a test system. The PAG binding capacity was around 3 mg protein per gram of corundum. Cytoplasm obtained from different E. coli strains was examined as an example of a complex matrix. The imidazole concentration was varied in the loading and washing buffers. As expected, higher imidazole concentrations during loading are usually beneficial when higher purities are desired. Even when higher sample volumes, such as one liter, were used, recombinant protein down to a concentration of 1 µg/mL could be isolated selectively. Comparing the corundum material with standard Ni-NTA agarose beads indicated higher purities of proteins isolated using corundum. His6-MBP-mSA2, a fusion protein consisting of monomeric streptavidin and maltose-binding protein in the cytoplasm of E. coli, was purified successfully. To show that this method is also suitable for mammalian cell culture supernatants, purification of the SARS-CoV-2-S-RBD His8 expressed in human Expi293F cells was performed. The material cost of the nickel-loaded corundum material (without regeneration) is estimated to be less than 30 cents for 1 gram of functionalized support or 10 cents per milligram of isolated protein. Another advantage of the novel system is the corundum particles' extremely high physical and chemical stability. The new material should be applicable in small laboratories and large-scale industrial applications. In summary, we could show that this new material is an efficient, robust, and cost-effective purification platform for the purification of His-tagged proteins, even in challenging, complex matrices and large sample volumes of low product concentration.