Journal of Innovation and Technology

The Effect of Matos Soil Stabilizer on Mechanical Properties of Soil Stabilized with Cement

Herlambang Adjie Wibowo — 2024-12-27

Analysis of PM2.5 Level Related to Vehicle Activities in Campus Parking Lot

Achmad Yahya Teguh Panuju — 2024-12-27

The number of vehicle usage, especially motorcycles, in Indonesia has significantly increased in the past 10 years, particularly among young people. This has had an impact on the declining air quality in public places, including on campus grounds. PM_2.5, as one of the hazardous pollutants to health, needs to be given special attention regarding its dispersion concentration in areas heavily frequented by the public, such as parking lots on campus. This study analyzes the level of PM_2.5 concentration in the campus parking lots at Universitas Lampung, with the aim of observing the pattern of PM_2.5 pollution in the campus area, considering the increasing number of motorcycles entering the campus every year. The measurement of PM_2.5 levels was conducted using a light scattering sensor in two parking lots with different microenvironments, and then its correlation with motorcycle activities at each location was analyzed using simple regression. Based on statistical analysis, it was found that the differences in microenvironments affect PM_2.5 levels significantly. The number of motorcycle activities also has a positive correlation with the level of PM_2.5, where the average PM_2.5 concentration recorded has exceeded the threshold set by the government, which is 15 µg/m³ per day. However, the effect of the microenvironment in this study is stronger than the number of vehicles. Therefore, in the future, appropriate policies and strategies are needed to reduce PM_2.5 concentrations in public areas, especially on campuses, to prevent the associated risks of the pollution.

The Effect of Sintering Temperature on The Adhesion Quality of Hydroxyapatite on Porous Tantalum for Cancellous Bone Implant Application

Rizal Adi Saputra — 2024-12-27

Porous tantalum has been recently recognized as a conventional orthopedic implant for bone substitute applications besides stainless steel, cobalt-chromium, titanium, and other metallic alloys. Porous tantalum has excellent mechanical and osseointegration properties similar to cancellous bone structure. To optimize the utilization, the dip coating technique was applied to coat porous tantalum with hydroxyapatite (HA). X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques investigate the coating characterization. HA is a bioceramic material that used for bone substitutes due to its chemical and structural similarity to bone minerals. Coated porous tantalum requires the sintering process of porous tantalum to adhere to HA. During the sintering process, various temperatures (650°C, 750°C, 850°C, 950°C, and 1100°C) were used to determine the optimum temperature for porous tantalum coated with HA. The heating rate is 1°C/1 min and the holding time is 60 minutes. The result shows that the optimum temperature of HA-coated porous tantalum is at 850°C. The morphology structure of the HA-coated porous tantalum shows that the adhesion between porous tantalum and HA is in good condition. The element in the HA-coated porous tantalum shows that the existence of HA is high.

Utilization of Spent Bleaching Earth Waste in Soil-Lime Stabilization for Road Body Foundation Layers Based on Index Properties

Syarif Razhik Ghazali — 2024-12-27

Spent Bleaching Earth (SBE) is a mixed material between bleaching earth and organic compounds derived from bleached crude oil. In addition, spent bleaching earth still contains a component of phosphoric acid. This phosphoric acid comes from the degumming process which is brought to the bleaching process by oil. According to Government Regulation Number 22/21 concerning Implementation of Environmental Management and Protection, this spent bleaching earth is classified as non-B3 waste depth. Chemical stabilization is by mixing chemicals into the soil material which causes a chemical reaction to occur between the mixing material and the soil which will produce new materials that have better quality. From the results of the physical properties experiment, it was found that the mixture with the optimum value for soil-lime stabilization was 10% SBE.

Comparison Study Between the Experimental and Finite Element Analysis (FEA) on a Static Load of Magnesium AZ31B as Biodegradable Bone Plate Material

M Arif Wicaksono — 2024-10-31

Biomaterials is an advanced material engineering technology that is used to help heal bone fractures or fractures. Currently, many biomaterials use materials such as titanium alloy, stainless steel, platinum, and chromium, but these materials cannot be degraded naturally so a second operation must be carried out to remove the installed biomaterial. Biomaterials are temporary in nature so when the bone returns to its original state, the biomaterial must be surgically removed. Research was conducted to obtain a design with a material that can be naturally degraded without causing toxicity. Magnesium AZ31B is a recommended candidate as a base material for degradable bone implants. Magnesium AZ31B material, it is expected to reduce or minimize the surgical removal of implant biomaterials. Bone plate geometry use plate bone dimension 150mm x 15mm x 3mm with variation 10 hole parallel and zigzag as well as with a bolt bone dimensions long 40 mm with pitch 1mm diameter 5mm. Test bending was conducted with ASTM E290-14 showing that on plate bone hole parallel with burden maximum 33,419 KN with a deformation maximum of 30.89 mm whereas for plate bone hole zig zag with the burden maximum 32,863 KN with deformation maximum big as 29.97 mm. From the study experimental that plate bone hole parallel have nature mechanic more tall compared with plate bone hole zig Zag although with the difference which is not significant. Whereas on simulation FEA plate bone hole parallel with burden 33,419 KN get results total deformation as big as 31,481 mm with von Mises stress 15,337 MPa, then for plate bone hole zig Zag with burden 32,863 KN with total deformation 32.466 mm and von Mises stress as big as 33,948 MPa. In testing by experiment and simulation FEA plate bone hole parallel get difference around 0.591 mm or 0.94% whereas for plate bone hole zig Zag in testing by experiment and simulation get difference around 2,893 mm or 4.60%.