The study of soil carried out from oil palm plantation soils at Garuda sakti street, Tapung, Kampar, Riau has been implemented since November 2019 to March 2020. This study aims to determine magnetic susceptibility, mass susceptibility, magnetic degree and to identify soil compositions and the content of heavy metals in the soils and to analyse the influence of content of heavy metals to the magnetic susceptibility. The samples were taken about one hundred points, then the samples were dried, cleaned, mashed and sifted. Magnetic susceptibility was measured using the Probe Magnetic Pasco PS-2162. Magnetic particles were separated from samples using the NdFeB magnet and identification of soil composition and the content of heavy metals were carried out using the XRF. The result shows that the value of magnetic susceptibility, mass susceptibility, magnetic degree are fluctuated and the compositon of the soils are Mg, Al, Si, P, K, Fe, Ca, Ti, V, Cr, Mn, Ni, Zn  S, Cl, Co, Cu, Ga, Ge, As, Br, Rb, Sr, Y, Zr, Nb, Ag, Eu, Re and Pb and proved that soil has been contaminated by heavy metals such as V, Cr, Al, Fe, Ti and Sr from the soils until increase the Magnetic susceptibility of that soils.

Research on the Analysis of Magnetic Properties and Content Identification of kampar River Sand Riau Province has been carried out. Sand samples taken in the Kampar River were then taken to  University of Riau instrumentation and magnetization laboratory to dry first, after which magnetic mineral separation was carried out using an Iron Sand Separator (ISS) . The next sample was measured its magnetic induction value using 2500 winding solenoids with currents (200, 400, 600, 800, 1000) mA with a fixed distance of 1 mm. The results showed that the magnetic susceptibility value for sand samples at point C was the highest value followed by the location of point B and point A with successive values of 13,767.96 x , 8,508.48 x  , and 8.008.10 x , and this value is included in the anti-ferromagnetic ilminite (FeTiO3) interval with a range of values (220-380000) x ,  . The results of the mass susceptibility value for the concentrate show that sand at the location of point C is the highest value followed by locations of points B and A with values of 13,969.70 x . 9,482.71 x .  and 6,441.25 x ., and this value is included in the inter ferromagnetic FeTiO3 ilminite interval with a range of values (46-8000 ) x .. X-Ray Fluorescence (XRF) test results for the Fe element have increased after ISS. Sand which is at point B has a greater percentage, followed by the locations of points A and C with values respectively 17.265%, 11.386% and 10.952%.

The magnetic susceptibility and heavy metal content of oil palm plantations soil has been determined. The magnetic particles of the soil were separated from non-magnetic particles using neodymium iron boron (NdFeB) magnet. The magnetic induction of the soil was measured using Pasco Probe PS-2162. The magnetic susceptibility value on the surface of the oil palm plantation soil varies between (685.99 to 1081.96) × 10 −5. This value is higher than the reference soil magnetic susceptibility that is 457.30 × 10 −5. The magnetic susceptibility values decrease as soil depth increases and at a depth of 40 cm the magnetic susceptibility value is close to the value of reference soil magnetic susceptibility. The X-Ray Fluorescence Spectroscopy (XRF) test result showed that the plantation soil has been contaminated with Cr, Fe, Ti, Sr, and V, this is in accordance with the magnetic susceptibility value of the plantation soil surface which is higher than that of the reference soil.

Receipt of radiation doses in patients by CT scan media really contributed to the radio diagnostic field. So far, volume Computed Tomography Dose Index (CTDIvol) and Dose Length Product (DLP) are the dose parameters used as a prescription of the dose to the patients from the examination process on the CT scan. However, these parameters have the disadvantage that they only describe the dose output from the device without regard to patient size. Size Specific Dose Estimate (SSDE) is a dose correction based on patient size and an effective dose is the dose value that arises due to differences in biological sensitivity values. Calculation of SSDE values and total effective doses were carried out in this study from data of patients who had undergone an abdominal CT scan examination. Patient radiation dose data were obtained from documents collected from the Radiology Department at the Prima Pekanbaru hospital. The data was obtained from examination results of Toshiba Asterion Multi (CTB 400 tube) CT scan of the abdomen of 20 patients. The data analysis shows that the average value of SSDE for male and female patients are 19.64 mGy and 17.4 mGy and the average total effective dose for male and female patients are 12.63 mSv and 9.16 mSv. These data indicate that the level of radiation dose received by patients is below the threshold that has been evaluated based on BAPETEN provisions.

Modification of iron oxide nanoparticles by doping with transition metals has been intensively reported and many applications have been proven. Magnetic and structural properties, and the catalytic activity of undoped and manganese doped iron oxide nanoparticles for degradation of methylene blue have been studied. Preparation of undoped and manganese doped iron oxide nanoparticles was done by ball milling method using Logas natural sand as raw materials. The magnetic properties of the samples were determined using vibration sample magnetometer (VSM). A detailed analysis of the loop hysteresis reveals a reduction of saturation magnetization of the samples towards higher manganese-doping concentration (wt.%). The reduction in magnetization from 13.25 to 11.67 emu/g and enhanced the coercivity on manganese-doped samples from 224.35 to 352.18 Oe are observed to produce an improvement in the catalytic activity for manganese doped iron oxide nanoparticles compared to undoped samples. Catalytic activity of undoped and manganese doped iron oxide nanoparticles in the degradation of methylene blue was studied through ultraviolet visible spectroscopy (UV-Vis). Manganese doped iron oxide nanoparticles exhibit better catalytic activity for degrading methylene blue (88.880%) compared to that for undoped iron oxide nanopartices (81.805%) for 300 minutes reaction time.