Journal of Mechanical Engineering

Akurasi Dimensi Komponen Multi-material Hasil Manufaktur Digital Light Processing (DLP) 3D Printing

2024-03-15T23:35:22+07:00

Workpieces resulting from 3D printing manufacturing which were initially only for rapid prototyping purposes, are now used for final products. In its development, a method is needed that can accommodate the creation of multi-material structures because there are complex structures that require hard materials and elastic materials in one part at once. Multi-material manufacturing with a laminate structure in DLP 3D printing can be done by changing the resin material periodically as needed. One important aspect in multi-material 3D printing manufacturing is dimensional accuracy. In this research, the accuracy of multi-material specimen layer thickness from DLP 3D printer manufacturing was studied. The specimens were manufactured with a uniform CAD design, but with varying numbers of material layer pairs. The thickness of each layer of the specimen is measured. From the measurement results, it is known that there is an error in the thickness of each specimen due to the bottom layer phenomenon and the influence of the penetration range of UV light in the DLP 3D printing technique due to differences in the color density of the resin material and the concentration of the photoinitiator.

Analisis Pengaruh Suhu Panel Surya Terhadap Output Panel Performance

2024-03-15T23:35:29+07:00

The main obstacle that greatly affects solar power output systems is the low conversion efficiency of solar panels, which is greatly influenced by their operating temperature. Failure to consider solar panel temperature increases the financial risks of installing the installation system. In this research, the output performance of solar panels was examined in outdoor conditions. All data was measured and recorded from 09.00 to 17.00, over 30 minute intervals. Panel temperature measurements were carried out using a Ditec C355 infrared thermometer. And then compared with using Pvsyst software. The output power of a solar panel is highly dependent on the solar radiation that falls on its surface. The amount of incoming sunlight is much higher during the hours from 11.00 to 13.00, which can be determined as the peak of the sun during the day. So it can be concluded that the ideal climate for setting up a large solar installation system is a cool and sunny climate.

Analisis Ukuran Partikel Nanosilica Pada Proses Alkali Fusion Silica Scaling Geotermal Dieng Menggunakan KOH

2024-03-15T23:35:35+07:00

One of the characteristics of the Dieng geothermal field is the high silica content in the production fluid which causes the appearance of silica scaling. The presence of silica scaling inhibits the energy extraction process and becomes waste that disturbs the environment. The silica scaling can be utilized as a nanosilica product for use as a reinforcing filler. Nano-sized powder is expected to improve the mechanical properties of a product with denser results. This research aims to synthesize nanosilica from geothermal scaling silica using the alkali fusion method. Nanosilica is obtained by reacting alkali KOH with silica scaling which has been reduced in size using ball milling. The fusion process is carried out using heat treatment at varying temperatures of 400, 450 and 500ºC. The fusion results were dissolved in distilled water for titration using 2M HCl with stirring using a magnetic stirrer until gelation was formed which was dried into silica nanoparticles. Characterization of the size of nanosilica powder using the Particle Size Analyzer (PSA) obtained the smallest size data at a fusion temperature of 400ºC with the size tending to increase as the fusion temperature increased, where these results were in line with the analysis of nanosilica images from Transmission Electron Microscopy (TEM) testing using ImageJ software. Compound analysis using Fourier Transform Infra-Red (FTIR) shows the presence of characteristic silica bonds. The results of X-Ray Diffraction (XRD) do not show sharp peaks so the compound has an amorphous phase.

Sintesis dan Karakterisasi Nanosilika dari Limbah Silica Scaling PLTP Dieng Melalui Metode Alkali Fusion NaOH

2024-03-15T23:35:14+07:00

Silica scaling is the main problem that arises in the operation of geothermal power plants (PLTP) in Dieng. Silica scaling can disrupt electricity production and cause a buildup of waste in the environment. Silica scaling has a high silica (SiO2) content so it has the potential to be used as a value-added material, namely nanosilica. One method to obtain nanosilica is alkali fusion. This research aims to obtain nanosilica from silica scaling waste from PLTP Dieng using the alkali fusion method as well as knowing the characteristics of the nanosilica produced. The alkali fusion process is carried out using NaOH as an alkali source. Then mixing silica scaling powder and NaOH at varying temperatures of 600°C, 650°C and 700°C to produce nanosilica. The resulting nanosilica was then characterized to confirm the success of the synthesis process in producing nanosilica particles. The characterization carried out included x-ray diffraction (XRD) to characterize crystallinity, Fourier transform infrared (FTIR) to characterize functional groups, transmission electron microscope (TEM) and particle size analyzer (PSA) to determine particle size. The results of this research showed that amorphous nanosilica was successfully synthesized from silica scaling using the NaOH alkali fusion method. It was found from the results of TEM and PSA characterization that the smallest particle size was produced at a fusion temperature of 650°C. Furthermore, FTIR data also confirms the existence of functional groups at wave numbers identical to silica.

Eksplorasi Energi Biogas di PT. Biro Teknik Sinar Baru

2024-03-15T23:35:42+07:00

Energy sources originating from fossil fuels such as petroleum, coal and others cause environmental damage and increase greenhouse gases. Cow dung is a renewable energy source that is rarely used but has many benefits after being produced into biogas which can be used as electricity and gas. The advantages of using livestock manure into biogas include renewable energy, biogas can reduce environmental pollution and reduce greenhouse emissions. In this research, we studied biogas energy exploration at PT Bureau Teknik Sinar Baru. A comparative study of the potential of biogas and LPG from several aspects, namely duration, volume of use, CO gas, and cost, has been carried out with the aim of evaluating the advantages and limitations of each of these energy sources. Based on the test results, biogas is 14 minutes faster, more economical 0.05 liters, and the CO gas produced is 0.20% - 0.33% smaller than LPG for boiling 5 liters of water. In conclusion, this study shows that biogas has the potential to be a cheaper, environmentally friendly and sustainable alternative energy source compared to LPG.

Pengembangan Acetylated Cellulose Nanofibers dari Microcrystalline Cellulose: Studi Perubahan Gugus Fungsi dan Indeks Kristalinitas melalui Asetilasi dan Nanofibrilasi

2024-03-15T23:35:20+07:00

Cellulose nanofiber (CNF) has promising potential as a reinforcement in polymer matrix nanocomposites. CNF is polar or hydrophilic due to having many hydroxyl groups. When CNF particles are combined with a non-polar polymer matrix, the CNF is difficult to distribute evenly and tends to agglomerate due to differences in polarity so that the strengthening effect of CNF is limited. To overcome this problem, it is necessary to chemically modify the CNF surface. Acetylation is one of the most widely used CNF surface modification methods to increase the compatibility between a non-polar polymer matrix and CNF. Through the acetylation process, some of the hydroxyl groups of CNF are replaced with acetyl groups which are hydrophobic. Furthermore, the CNF resulting from the acetylation process is known as acetylated CNF (acetylated cellulose nanofibers or ACNF). The acetylation process is carried out by first mixing microcrystalline cellulose (MCC) particles into 75 mL of acetic anhydride solution. Next, the mixture was stirred using a high-speed blender for 30 minutes for the MCC nanofibrillation process to occur. In this research, the influence of acetylation and nanofibrillation processes on the characteristics of ACNF was studied through studying chemical structure changes using ATR-FTIR and crystallinity index using XRD. The results of the ATR-FTIR analysis show that there are 3 new peaks in the ACNF spectrum, namely at 1720, 1369 and 1203 cm-1, which proves that there is a change in the structure of cellulose after being given acetylation treatment. The results of XRD show that surface treatment of acetylation and nanofibrillation with a high-speed blender increases the ACNF crystallinity index value by 82.53%. Overall, the resulting ACNF has great potential as a reinforcement for polymer matrix nanocomposites.

Analisis Pengaruh Banjir Rob Terhadap Kualitas Air Tanah Di Kawasan Pesisir Selatan Puger Kabupaten Jember

2024-03-15T23:35:25+07:00

The potential benefits of a beach for the surrounding community are numerous, including increasing the tourism sector and supporting the economy of local residents. Apart from this potential, there is also the potential for disasters, one of which is ROB flooding. Recently there was a tidal flood that hit the southern coast, causing seawater to enter residential areas and damage various public facilities in the Puger coastal area. The aim of this research is to identify the influence of tidal floods that occurred in the southern coastal area of Puger, on groundwater quality, in terms of water quality in accordance with the quality standards of Minister of Health Regulation No. 2 of 2023 concerning Implementing Regulations of Government Regulation Number 66 of 2014 concerning Environmental Health. The method used is descriptive qualitative conservation data and sampling at three locations by conducting laboratory tests. From this research, it can be concluded that there is a decline in the quality of groundwater in the affected area which includes three observation locations. Where the TDS parameter is still below the quality standard of <300 mg/L, while for salinity and e-coli each has a value greater than the established quality standard. In this study, both parameters had <0% with values for sampling 1 (2 per cent) sampling 2 (0.9 per cent) and sampling 3 (0.5 per cent ), for salinity and <0 CFU/100ml for e-coli content with values for sampling 1 (50 CFU/100ml), sampling 2 (70 CFU/100ml) and sampling 3 (100 CFU/100ml). The ROB floods that occur in coastal areas result in the quality of groundwater becoming polluted and it must be treated first before it can be used by local communities.

Pengaruh Dimensi Saluran Buang dan Sudut Kipas Generator Terhadap Kinerja Perangkat Oscillating Water Column

2024-03-15T23:35:32+07:00

This research aims to investigate the potential for optimizing ocean wave energy conversion using an Oscillating Water Column (OWC) device by focusing on the influence of variations in exhaust duct diameter and generator fan angle. Electrical energy, as a major need in Indonesia, demands exploration of renewable energy sources as an alternative to fossil fuels. Experiments were carried out by varying the exhaust duct diameter (5.5 cm, 4.5 cm, 3.5 cm) and generator fan angle (20°, 25°, 30°). The research results show that there is a significant influence of these two variables on OWC performance. The results of wind speed measurements show that with an exhaust channel dimension of 5 cm, the wind speed at an angle of 45° reaches 2.24 m/s, while at angles of 35° and 40° it is 0 m/s. In the same dimensions, increasing the exhaust duct dimensions increases the wind speed, with a dimension of 15 cm providing optimal results at all fan angles. Measuring the fan RPM in the exhaust duct dimensions (5 cm, 10 cm, 15 cm) shows that in the dimensions 5 cm and 15 cm, the fan RPM is 0 at an angle of 35°. Increasing exhaust duct dimensions, especially the 10 cm and 15 cm dimensions, provides a significant increase in RPM at 40° and 45° angles. The 15 cm dimension provides the best performance, especially at 45° angles. Voltage measurements at three angles (35°, 40°, 45°) with varying exhaust channel dimensions show that at dimensions of 5 cm and 15 cm, the voltage is 0 V at an angle of 35°. Increasing the fan angle, especially in the 10 cm and 15 cm dimensions, provides increased voltage. Dimensions 10 cm, at an angle of 45°, reaches the highest voltage of 24.68 V.

Karakteristik Semburan Bahan Bakar Aviation Gasoline dengan Nozzle Pesawat Cessna 172S

2024-03-15T23:35:38+07:00

Avgas fuel is fuel from aviation engines, namely piston engine type aircraft, where the spray of this fuel is very influential on the life of a piston type aircraft engine. The characteristics of avgas fuel bursts, namely the distance, temperature and shape of the spray, are rarely studied in Indonesia, so with using experimental and varied data collection techniques, we obtained the characteristic results of the avgas type fuel spray and its mixture, where the mixture of 20% ethanol with a distance of 21 cm at a pressure of 3 bar is the lowest point of the fuel mixture spray temperature, namely reaching 15oC, the effect of The mixture of fuel with ethanol means spots on the walls and combustion chamber due to the mixture of alcohol containing water so that traces and water spots can become crust on the combustion chamber.

Pengaruh Bentuk Permukaan Piston Rata (Flat) Dan Piston Cembung (Dome) Terhadap Performa Dan Emisi Gas Buang Pada Mesin Sport 200cc

2024-03-15T23:35:17+07:00

The aim of this research is to determine the effect of engine performance (torque and power), as well as exhaust emissions after replacing the piston. Tests were carried out on a 200CC engine with flat piston specifications with a diameter of 65.0 mm and replaced with a convex piston with a diameter of 65.0 mm using pertalite fuel. The research results obtained by replacing the convex piston (dome) caused the volume of the combustion chamber to decrease resulting in increased torque and power. There was an increase in torque of 0.02607 ft-lbs and an increase in power of 41.95384 HP, then the compression ratio increased by 0.5%. In exhaust gas emissions containing CO, HC, O2, CO2 using a gas analyzer with the results of research on flat pistons and dome pistons, it can be seen that emissions from convex pistons (dome) have increased compared to flat pistons. with the highest increase in stationary of 6.17% in CO emission content due to incomplete combustion residue, which means that the type of piston has a significant influence on exhaust gas emissions. Then the exhaust gas emission test results also show an increase in the O2 emission content on the flat piston at RPM 5000 with a value of 4.24% due to the mixture of oxygen and fuel being more perfect, but on the convex piston (dome) there is a significant increase Compared to a flat piston only at RPM 6500 with a value of 4.53% in O2 emission content. The HC and CO2 emissions content shows unstable or changing values. Apart from that, variations in engine speed also affect the exhaust emissions produced.