There are several methods for measuring the particle size distribution of the comminuted minerals, but the most used in situ analysis methods are sieving and microscopic analysis due to the particle size characteristics. This paper presents the improved method of the microscopic image analysis to improve the accuracy estimating the particle size distribution of comminuted minerals. The image processing methods we used are microscopic image stitching, individual particle segmentation with watershed and deep learning and individual particle weight estimation with shape factor. We experimented with three samples, namely ferruginous quartzite, coal and magnetite, for estimation of the particle size distribution, and confirmed to improve the accuracy estimation through comparison with sieving test.

The magnetocaloric effect of the mixed manganites La_0.7Ca\(_{{0.3-x}}\)Sr_xMnO₃ (x = 0.05, 0.07, and 0.10) prepared by sol–gel method have been investigated. Using Hamad’s phenomenological model, we have estimated the important magnetocaloric properties such as the magnetic entropy change and the relative cooling power. Our work shows that Curie temperature and the relative cooling power of La_0.7Ca\(_{{0.3-x}}\)Sr_xMnO₃ manganites increase with increasing Sr content, while maximum magnetic entropy change decrease slightly. Tunable Curie temperature and considerable magnetocaloric effect in these manganites are advantageous for applications in sub-room and near-room-temperature magnetic refrigeration.