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The primary advantage of the high energy ball milling (HEBM) process is its ability to synthesize a homogeneous mixture with submicron (up to nanoscale) particle size. This approach is a viable process for particle size reduction and grain refinement of magnetic powders, which affects their domain structure and by extension the resulting magnetic properties. In this research, we designed a 9-ball milling experiment by keeping the rotational speed constant at 300rpm and varying the ball-to-powder ratio of 5:1, 8:1, and 10:1 for 6hrs, lOhrs, and 14hrs milling times. The strontium ferrite magnetic powders subjected to HEBM were analyzed for crystallite size and behavior via XRD, particle size reduction via SEM/ImageJ software/originLabPro, and magnetic performance via powder-based VSM measurement. The magnetic performance of the ball-milled strontium ferrite powders shows a good combination of appreciable increment in the S-values (a ratio of the remanence to saturation magnetization) and a considerable decline in coercivity (<10% decrease) at 6hrs of milling duration. The particle size obtained at 6hr-8:1BPR is 0.59 µm with about 44% reduction from the 1.05 µm particle size of the unmilled strontium ferrites, which is within the reported single-domain particle critical size (0.5 µm - 0.65 µm). The particle size reduction of 0.59 µm at 6hr-8: lBPR would be beneficial in enabling strong interfacial bonding when the ball­milled strontium ferrite powders are used in polymer-bonded magnets. 

This method for extracting protein from ground coral samples is based on the Bradford assay for the colorimetric detection and quantification of total protein (Bradford, 1976) and is compared to a known standard dilution of bovine serum albumin (BSA). Pierce Inc. and Bio-Rad have developed the reagents and standards necessary for completing the extraction. There are five parts to quantifying total soluble protein in ground corals: 1) grind and sub-sample the coral and store at -80 °C until ready to extract, 2) solubilize protein via cell disruption [detergent lysis and freeze-thaw lysis], 3) separate the dissolved protein from tissue and skeletal particles, 4) quantify the protein concentration via Bradford microassay procedure, and 5) standardize the protein concentration to ashfree dry weight (AFDW). This method was originally developed by Rowan McLachlan with the assistance of Jamie Price and Kerri Dobson and with the guidance of Dr. Noah Weisleder and Andréa Grottoli at The Ohio State University. This protocol was written by Rowan McLachlan and reviewed by all co-authors. dx.doi.org/10.17504/protocols.io.bdc8i2zw