Abstract: The present invention relates to a method for preparing magnetite nanoparticles from low-grade iron ore using solvent extraction and magnetite nanoparticles prepared by the same. According to the method for magnetite nanoparticles from low-grade iron ore of the present invention, it is possible to prepare high-purity magnetite nanoparticles having a purity of 99% or higher by solvent extraction using low-grade iron ore as a starting material, and thus it is possible to reduce the processing cost and the amount of energy used, thus supplying a high-efficiency magnetite nanoparticle adsorbent, which can be industrially applied to wastewater treatment or desalination plant, in large quantities at low cost. In particular, it is possible to effectively treat livestock wastewater, heavy metal wastewater, oil discharged into rivers, etc. at low cost, thus significantly contributing to the prevention of environmental pollution.

Abstract: Disclosed are an apparatus and a method of measuring porosity and permeability of a carbon dioxide underground storage medium. Both of the porosity and the permeability are measured in the state that the confining pressure is applied once. The variation characteristic in the porosity and the permeability of the core sample according to the salt precipitation occurring when supercritical carbon dioxide is injected is continuously measured. The apparatus includes a holder receiving a core sample, a pressure pump applying a confining pressure to the core sample, a gas chamber storing gas and supplying supply the stored gas to the core sample, first to third pressure gauges measuring an internal pressure of the gas chamber and front and rear portions of the holder, and a gas flow meter measuring a flow rate of gas.

Abstract: Provided are embodiments of a section marking apparatus and method for dividing a geological survey site into one or more sections. In some embodiments, the section marking apparatus includes a case part, a fixing shaft part, a section marking part, and a driving pin part. The fixing shaft part is accommodated in the case part. The section marking part is coupled to the fixing shaft part, received in the case part, and has a marker string configured to be extracted to the outside of the case part. The driving pin part is coupled to the fixing shaft part and configured to be driven into a ground surface to secure the section marking apparatus to the ground surface. Accordingly, the section marking apparatus can be used to divide a site when the ground is flat or when the ground is uneven and/or has a slope.

Abstract: A ring shear apparatus for measuring a shear strength of soil samples. The ring shear apparatus considering a wall-slip effect including: an upper ring for forming a first accommodation portion having a ring shape in which soil samples are accommodated; a lower ring for forming a second accommodation portion that corresponds to the first accommodation portion of the upper ring and has a ring shape in which soil samples are accommodated, closely attached to a lower portion of the upper ring and rotatably installed relative to the upper ring; a rotating unit for rotating the lower ring relative to the upper ring; and a shear strength measuring sensor combined with the upper ring and for measuring a shear strength of the soil samples, wherein a plurality of protrusions that protrudes from the lower ring is formed on an inner circumferential surface of the lower ring along a circumferential direction of the lower ring in order to prevent the soil samples from being slid when the lower ring is rotated.