KAJIAN EKSPERIMENTAL PENGARUH CAMPURAN ETANOL DAN PERTAMAX TERHADAP KONSUMSI BAHAN BAKAR MOTOR INJEKSI 125CC

Abstract: Experimental Study of the Effect of a Mixture of Ethanol and Pertamax on Fuel Consumption of a 125cc Injection Motorcycle. Currently the need for petroleum is quite high. This is because transportation and industry still rely on petroleum as the main fuel. Ethanol has similar properties to Pertamax fuel which can be applied to every vehicle, especially two-wheeled vehicles. The aim of this research is to find out how the addition of ethanol to Pertamax fuel affects the amount of fuel consumed by injection motorbikes. The mixture percentages that will be tested are E10+P90, E20+P80, and E30+P70 respectively, and then the consumption results are compared with tests using pure Pertamax (E0+P100). The test results show that the use of Ethanol-Pertamax mixed fuel can be reduced when the percentage of the ethanol mixture is below 50%. Where the lowest fuel consumption is the E30+P70 mixture at 16.4% compared to pure Pertamax consumption

ANALISIS KEKERASAN SAMBUNGAN LAS MIG BAJA KARBON RENDAH DENGAN BERBAGAI VARIASI KAMPUH

Along with technological developments, the use of metals such as steel cannot be separated from the welding process. Where welded joints have advantages in the form of lightweight construction, able to withstand high loads, and are more economical. One of the factors that must be considered in producing a good welded joint is the weld camp. Welding camp are used to accommodate filler material on the metal, so that the determination of the type of camp is based on the needs of the construction being built. The purpose of this study was to analyze the hardness of low carbon steel MIG welded joints with various variations of camp and welding temperature. The test material used was ST 37 low carbon steel with a thickness of 6 mm and a width of 100 mm. Tests were carried out to compare the weld joint hardness values with the application of V, I, and K seams on each welding electric current of 130 A, 150 A, and 170 A. The test results showed that in all types of seams, the higher the welding electric current. Applied, the greater the hardness value of the welded joint obtained. The highest hardness value was obtained at a welding current of 170 A with a V camp of 89.8 N/mm2

KAJIAN KOMPUTASI DAN EKSPERIMENTAL PENGARUH KONTROL AKTIF TERHADAP HAMBATAN AERODINAMIKA MODEL KENDARAAN

Abstrak: Kajian Komputasi dan Eksperimental Pengaruh Kontrol Aktif terhadap HambatanAerodinamika Model Kendaraan. Dinamika aliran udara sangat dipengaruhi oleh pembentukan separasi di sekitar bodi kendaraan. Separasi aliran menjadi pemicu perbedaan tekanan yang signifikan antara sisi depan dan belakang sehingga muncul efek tarikan ke arah belakang sebagai kontributor utama besarnya hambatan aerodinamika yang diterima kendaraan. Penelitian ini fokus pada kajian hambatan aerodinamika dengan memperhatikan karakteristik pola aliran yang terbentuk dan distribusi tekanan pada dinding belakang model kendaraan melalui metode simulasi komputasi dan eksperimental laboratorium. Kontrol aktif tiupan ditempatkan pada sisi atas dinding belakang Ahmed model dan diatur pada kecepatan 1.5 m/s. Hasilnya menunjukkan bahwa penggunaan kontrol aktif tiupan pada sisi belakang mampu menunda separasi, meningkatkan koefisien tekanan, dan mengurangi hambatan aerodinamika model kendaraan.   Abstract: Computational and Experimental Studies of the Effect of Active Control on Aerodynamic Drag of Vehicle Models. The dynamics of air flow is strongly influenced by the formation of separations around the vehicle body. The flow separation triggers a significant pressure difference between the front and rear sides so that a rearward pull effect appears as the main contributor to the amount of aerodynamic drag received by the vehicle. This research focuses on the study of aerodynamic resistance by paying attention to the characteristics of the flow pattern formed and the pressure distribution on the rear wall of the vehicle model through computational simulation methods and laboratory experiments. The blowing active control is located on the upper side of the back wall of the Ahmed model and is set at a speed of 1.5 m/s. The results show that the use of blowing active control on the rear side is able to delay separation, increase the pressure coefficient, and reduce the aerodynamic drag of the vehicle model

Pengaruh pendinginan fluida udara terhadap kinerja fotovoltaik dengan variasi laju aliran udara

This research aims to evaluate the influence of using air as a coolant on photovoltaic module's power output and electrical efficiency. Fossil energy, as the primary energy source today, has limited supply and presents challenges in meeting future energy demands. In an effort to address this issue, we conducted tests by implementing an air cooling system using a blower at the bottom of the photovoltaic module. The tests were conducted with varying air flow rates, and the results indicate that the use of air cooling can enhance the power output and efficiency of the photovoltaic module. The average power output increased by 31.66 Watts with an efficiency of 3.52%. However, when the air flow rate increased by 1.5 m/s, there was an average power decrease of 28.9 Watts and an efficiency decrease of 3.22%. These findings demonstrate that air velocity affects the temperature, power output, and efficiency of the photovoltaic module

KAJIAN PENGARUH KONTROL ALIRAN TERHADAP KOEFISIEN HAMBAT MODEL KENDARAAN

The characteristics of the airflow that is formed around the vehicle body affects the value of the resistance acting on the vehicle. When it reaches the rear edge of the vehicle, the flow undergoes a process of separation. So modification of the vehicle body design that is able to reduce the separation is urgently needed. Flow engineering around the vehicle body can be obtained by modifying the shape which is considered more aerodynamic. Meanwhile, flow engineering can also be obtained through the application of an active control system in areas that are considered to have the potential to initiate flow eddies on the rear side of the vehicle and have a major influence on the formation of flow separation. This research aims to examine the impact of the application of flow control blowing technique on the resistance of the modeled vehicle. The geometric angle of the front wall is determined to be 35°. The research uses a numerical computational approach with a standard k-epsilon as a turbulence model. The upstream velocity applied is 13.9 m/s, while the blowing velocity is set at 0.5 m/s. The research results prove that the application of blowing flow control has succeeded in minimizing the formation of wake structures and has the effect of delaying separation and has succeeded in reducing the aerodynamic drag coefficient to 9.3187%

EFEKTIVITAS KOMUNIKASI KLINIK AGRIBISNIS DALAM MENDUKUNG KEGIATAN PENANGKARAN BENIH PADI SAWAH DI KECAMATAN WONOSARI

The effectiveness of agribusiness clinic communication is a success in achieving the goal of agribusiness discipline of agribusiness by looking at the level of knowledge and attitude change from farmers after communication. This study aims to analyze the factors that influence the effectiveness of agribusiness clinic communication in supporting the breeding of paddy field seeds in Wonosari District, to know the communication process in agribusiness clinic service, and to know the effectiveness of agribusiness clinic communication in supporting the breeding activity of paddy paddy seeds in kecamatan wonosari. The research method used in this research is survey with data analysis using binary logistic regression. The results of this study show the influence of the accuracy of media extension on communication effectiveness. Communication process at the time of planning, execution, evaluation of activity sah walks well, and communication that happened at agribusiness clinic in support of breeding activity of paddy rice seedlings good enough but not yet effective. This is indicated by the level of knowledge of farmers about seed breeding activities of rice paddy is quite good and there are still farmers who have not responded well the existence of this agribisnis clinic. agribusiness clinic is actually very useful for them in supporting the breeding activities of rice paddy seeds in Wonosari District but the communication process that occurs in it should still be improved

EFEK PENERAPAN KONTROL AKTIF BLOWING TERHADAP TARIKAN AERODINAMIKA MODEL KENDARAAN

Vehicle stability when driving is an issue that needs attention because it relates to comfort in driving and the effectiveness of fuel consumption. This is caused by the large aerodynamic drag force of the vehicle due to the structure of the air flow which flows regularly and experiences separation when it reaches the rear end point of the vehicle. This separation of the flows causes significant negative pressure on the rear window due to the return flow which does not follow the shape of the vehicle body. The purpose of this study was to analyze the effect of implementing active control of blowing type flow on vehicle models on aerodynamic drag. This study applies a numerical computational method with a modified Ahmed body model as the main object of research. The active blowing control is placed at the rear end of the model which is considered the initial separation area. Blowing speed was varied 0.2 m/s, 0.8 m/s, 1.5 m/s, and 2.0 m/s and was tested at an upstream speed of 16.7 m/s. Research results indicate that the application of active blowing control has succeeded in providing a delay in separation effect, reducing turbulence and reducing aerodynamic drag by 8-9%

ANALISIS PENGARUH VARIASI SUDUT KEMIRINGAN TERHADAP OPTIMASI DAYA PANEL SURYA

Abstrak: Analisis Pengaruh Variasi Sudut Kemiringan Terhadap Optimasi Daya Panel Surya. Di Gorontalo suhu atau temperature udara yang tinggi yang dapat mempengaruhi kinerja pada panel surya. Suhu udara di Gorontalo pada siang hari dapat menembus angka diatas 34°C dibandingkan suhu optimal operasi dari panel surya sendiri adalah 25°C. Rumusan masalah dalam penelitian ini adalah apakah ada pengaruh perubahan sudut sel surya terhadap intensitas cahaya. Sedangkan Tujuan dari penelitian ini adalah upaya mengoptimalkan output tegangan, arus dan daya pada sel surya agar lebih maksimal. Salah satu metode pengoptimalan sel surya adalah dengan memvariasikan sudut kemiringan panel surya 9˚, 12˚ dan 15˚. Metode pada penelitian ini dengan melakukan pengukuran besaran intensitas cahaya matahari, arus dan tegangan dengan menggunakan panel surya 50 WP, pengukuran tersebut dilakukan selama 9 hari. Hasil analisis pada penelitian ini adalah persentase peningkatan daya sebesar 43.85 Watt pada sudut kemiringan 15˚, sedangkan daya output mengalami penurunan pada sudut kemiringan 12˚ dan 9 ˚ yaitu 41.70 Watt dan 39.43 Watt. Secara keseluruhan perubahan arah sudut sel surya berpengaruh terhadap intensitas cahaya matahari yang berakibat pada kuat lemahnya tegangan yang diterima panel sel surya. Semakin besar intensitas cahaya yang diterima, maka semakin besar pula tegangan yang dihasilkan panel surya. Kata kunci: sel surya; intensitas cahaya; sudut azimuth; daya Abstrack: Analysis of the Effect of Tilt Angle Variations on Solar Panel Power Optimization. In Gorontalo the temperature or air temperature is high which can affect the performance of the solar panels. The air temperature in Gorontalo during the day can reach above 34°C compared to the optimal operating temperature of the solar panels themselves which is 25°C. The formulation of the problem in this study is whether there is an effect of changing the angle of the solar cell on the light intensity. While the purpose of this research is an effort to optimize the output voltage, current and power in solar cells to be more leverage. One method of optimizing solar cells is by varying the angle of inclination of the solar panels to 9˚, 12˚ and 15˚. The method in this study is to measure the intensity of sunlight, current and voltage using a 50 WP solar panel, the measurements were carried out for 9 days. The results of the analysis in this study are the percentage increase in power of 43.85 Watt at an angle of 15˚, while the output power decreases at an angle of 12˚ and 9˚, namely 41.70 Watt and 39.43 Watt. Overall changes in the direction of the solar cell angle affect the intensity of sunlight which results in the strength and weakness of the voltage received by the solar cell panel. The greater the intensity of light received, the greater the voltage generated by the solar panel. Kata kunci: solar cell; intensity of light; azimuth angle; powe