This paper presents flexural and tensile properties of sugar palm (Arenga pinnata) fibres-reinforced polyester composites study. The fibres were treated by alkaline solution with 5% NaOH solution for 2 hours of soaking time. The composites were prepared with different orientations of fibres (i.e. 0° + 45°, 0° + 90°, 45° + 90°, and 45° + (-45°)), while the ratio between Arenga pinnata fibres and polyester is 30 percent volume. Hand lay-up method was employed to produce the specimens. ASTM D-790 03 and ASTM D-3039 standard were employed to characterize the specimens in good sequent. As the result, the specimen with 45°+90° orientation generated maximum important values both in flexural strength (24.03 MPa) and modulus (4.01 GPa), tensile strength (23.84 MPa) and modulus elasticity (0.97 GPa). This is due to palm fibres as reinforcement that forms an angle of 90 ° or increasingly upright to the load crossing field (load of bending) and tensile load giving the effect of maximum reinforcement compared to other fibres orientations.

This work implicates the synthesis of biochar-hematite nanocomposite from bamboo sawdust and its photodegradation characteristic for remazol brilliant blue. The nanocomposite was prepared through a one-step pyrolysis process in a tubular furnace under a flow of nitrogen and impregnation using FeSO4.7H2O and FeCl3.6H2O. The physicochemical properties were characterized by x-ray diffraction and Fourier transform infrared spectroscopy, which confirmed that hematite was successfully identified on the surface of the nanocomposite. The results also show that the nanocomposite is suitable for photodegradation application. The decolorization of remazol brilliant blue is suitable with the Langmuir isotherm model and pseudo-second-order kinetic model. At pH = 1, initial concentration = 200 mg/L, contact time = 60 minute and nanocomposite dosage 0.4 g/L, the decolorization efficiency reached 96.9%.

At the smallest scale, hydropower or pico-hydro can be produced by utilizing water flow at the piping system. This paper discusses about the performance of a water bulb-turbine in a water piping water system using the Computational Fluid Dynamic (CFD) method. This study aims to analyze the effect of flow rate and speed on the efficiency of water bulb-turbine using Solidworks Flow Simulation 2016. The propeller turbine design used in this study has 4 blades and a blade angle of 200, and the static bulb using with a ratio of 0.6 to the pipe diameter. The parameter in flow rate applied in this study is between 7 and 13 L/s and for speed parameter between 100 and 1700 rpm. The final result of this study indicates that the efficiency of the water bulb-turbine is a directly proportional increase of flow rate and the highest efficiency reaches at flow rate 13 L/s and 1300 rpm.

The purpose of this study is to synthesize and characterize of iron sand from the south coastal area of Purworejo, Central Java. Iron sand was mechanically filtered using permanent magnets 35 times. The filtered iron sand was characterized using x-ray diffraction (XRD) to determine the compound contained therein and his physical characteristics. The filtered iron sand was heated at temperatures of 800 ° C and 900 ° C for 5 hours in the furnace and after it was cold and followed by XRD testing. Based on the x-ray diffraction pattern, a single phase Fe2 O3 as a permanent magnet base can be formed after a 900 ° C heating process for 5 hours.

Pressure vessel is a container that has been used to contain a pressurized fluids, either oil, gas, or other chemical fluids. It is widely used for the oil, gas and other chemical based industries. Nowadays, finite element analysis is commonly used to reduce the high cost of testing a pressure vessel before manufacturing process. However, further validation is needed to ensure the results of the simulation and safety of the pressure vessels. In this study, theory of distortion energy is used as the tools of validation based on materials properties and behavior. And finally to ascertain wether the pressure vessel is possible for production or a refinement for safety is needed. The results of the study shown that theory of distortion energy can be used as validation tool for finite element analysis on a pressure vessels, however it cannot ensure the safety. Therefore other validation methods are needed to ascertain the safety of the pressure vessel discussed in this report. The cost analysis shown that failure theory combined with other calculation methods can save costs in pressure vessel testing, although some fairly expensive tests cannot be avoided.

Biopolymers are utilized extensively in the medical field. The production of biodegradable bone screws for bone implants utilizing biopolymer materials is one of the advances developments. Polylactic acid (PLA) is a biopolymer frequently employed in medicinal applications. Using 3D printing, this research was done to create a biodegradable bone screw derived from PLA. The 3D printing process was chosen to reduce the cost and duration of bone repair. A nozzle temperature of 210oC and a bed temperature of 60oC are utilized in the production of biodegradable PLA screws. The torque test, fracture analysis, density test, and biodegradation test were utilized to characterize biodegradable bone screws. The results of this study will be compared with commercial biodegradable bone screws (BIOSURE HA). The findings of torsion tests indicate that commercially biodegradable bone screws have superior clamping quality than PLA-based biodegradable bone screws. The degradation rate of commercial biodegradable bone screws is greater than that of PLA-based biodegradable bone screws. In addition, commercial bone screws are denser than PLA-based biodegradable bone screws.

The purpose of this study is to determine the tensile and flexural strength of Arenga pinnata fibres-epoxy as composite material. The Arenga pinnata fibres were soaked in 5 % NaOH solution for 2 hours. The specimens of the composite were prepared with different orientations Arenga pinnata fibres (i.e. 0° + 0°, 0° + 45°, 0° + 90°, and 45° + 90°). The Arenga pinnata fibres were mixed with epoxy and hardener also at the fibres volume percentage of 40%. The hand lay-up (HLU) process in this experiment was to produce a specimen test. The dimension of the specimen test for the tensile and flexural test was adapted from the ASTM D-3039 and ASTM D-7090 03 respectively. Results from the tensile test and flexural test of Arenga pinnata fibres reinforced epoxy composite, show the orientation 0° + 0° has the maximum of tensile and flexural strength, which are the value of tensile and flexural strength are 77.385 MPa and 76.38 MPa respectively. The tensile test shows that the fibres orientation parallel to the tensile force will give a maximum strengthening effect. The bending test shows that the orientation of the fibres across the compression force will produce maximum flexural strength.

Chitosan has been broadly utilized in bone scaffold production because of its antibacterial qualities, low toxicity, biodegradability, biocompatibility, and ability to aid regeneration processes in wound healing. In this work, chitosan was produced from crab shell waste through demineralization, deproteination, and deacetylation, utilizing HCl 1:7 (v/v), NaOH 3%, 1:10 (v/w), and NaOH 50%. The aim of this study is to examine the deacetylation temperature’s impact towards the crystallinity index, chemical bond, degree of deacetylation, and morphology of chitosan synthesized. The deacetylation procedure was conducted for eight hours at temperatures of 100°C, 120°C, and 140°C. The synthesized chitosan was evaluated by utilizing XRD, FTIR, and SEM methods. According to the findings of this investigation, deacetylation at a temperature of 140 °C produced the highest degree of deacetylation, resulting in the highest quality chitosan. In addition, compared to other obtained chitosans, the shape of this result of synthesis is homogenous. At a deacetylation temperature of 140°C, the amounts of deacetylation degree, and crystallinity index of the chitosan were, in order, 81%, and 44%.