Portal Jurnal Politeknik Negeri Semarang
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Performance Characteristics of Savonius Wind Turbines With Variations Air Gaps in Supporting the Development of Renewable Energy
Get PDFTo overcome the occurrence of an energy crisis in the future, an innovation / invention of energy that is environmentally friendly and energy sources will not run out in the future. Energy sources that are environmentally friendly and their potential when developed is very large, one of which is energy sources derived from wind energy. This study aims to determine the effect of wind speed on the performance of wind turbines. To find out the performance characteristics of wind turbines with variations in air gaps. The research method begins with the design / design of the wind turbine, then continues the manufacturing stage, the assembling and installation stage, the testing of tools and analysis, the tests carried out include testing the performance characteristics of the wind turbine. The parameters measured in this study are rotation, torque as well as calculating the kinetic power produced, TSR and CP. The test results conducted showed that the 200 mm air gap Savonius wind turbine with a value of CP = 0.02480-0.15658 had optimum work at low wind speeds (4 m / s). Meanwhile, the 170 mm airborne Savonius wind turbine with a value of CP = 0.00593-0.14668 has optimum work at high wind speeds (8 m / s to 9 m / s). Keywords- wind turbine savonius, air gap, coefficent of power
Solar Cell Outdoor Bench Design In Open Public Space For Gadged Charging Station
Get PDFAbstract””The increase in electrical energy is increasing along with the needs of rapidly developing technology. However electricity technology also produces negative impacts such as air and noise pollution caused by power plants. Electrical energy generation is still mostly generated from fossil fuels. A solution that can overcome this problem is to switch to more environmentally friendly electricity technology, such as solar panels. This solar powet plant can be used as an option as a charging energy source in a smart furniture. This research aims to make Solar Cell Powered Outdoor Charging Bench technology. This bench has several important components, namely: Solar Panel, Solar Charging Controller (SSC), inverter, and battery. This Outdoor Bench is placed in an open place such as a park, Public Open Space and so on which will be used as a charging place for cellphones or laptops. The way this bench works starts with the absorption of solar heat by solar panels on the roof of the bench which is converted into low-voltage electrical energy, then this energy is stored in a dry battery (battery) through SSC, low-voltage electricity is converted through an inverter, and this inverter channels electricity to the socket, so that the charging bench can be used properly
Language Register in Pak Joko Widodo”™s Speech Text on Independece Day 2017
Get PDFAbstract Pak Joko Widodo”™s Speech Text on Independence Day 2017 has concerned many aspects such as ideology, politics, economics, socio-culture, religion, and defense and security system. All Indonesian People then think that this is popular as the concept of ”˜Wawasan Nusantara”; i.e. the concept of how to build this country physically and non-physically. This of course comprises certain patterns of both written expressions and spoken expressions. The written expressions are the text written as the preparation of the speech; while the spoken expressions are the text delivered as the speech on Independence Day 2017. The discussion of these expressions then covers the three dimensions of language register i.e. field, tenor, and mode. Field concerns with social activity taking place, for example; foot ball, cooking, stamp collecting, studying Australian history, ideology, politics, economics, socio-culture, religion, defence and security system etc.; tenor concerns with the relationships between participants; this relationships can be described in terms of power (equal or unequal status), contact (how often you have contact with the person to whom you are speaking or writing), or affect (attitudes and feelings towards topics and participants), the relationships that exist between participants or the audience for whom a text is written, have a considerable impact on language that is used; and mode concerns with what channel of linguistic communication; and also relates to cohesive ties operating in spoken or written texts. Key-words: speech text, language register, field, tenor, and mode
THE EFFECT OF RETURN ON ASSETS (ROA), DEBT TO ASSETS (DAR), EARNINGS PER SHARE (EPS), GROWTH, AND SIZE ON COMPANY VALUE IN MANUFACTURING COMPANIES
Get PDFThis study aims to obtain empirical evidence of the effect of return on assets, debt to assets, earnings per share, growth and size on firm value. This study uses quantitative secondary data with purposive sampling method and multiple linear regression analysis, the total sample in this study is 30 manufacturing companies listed on the Indonesia Stock Exchange in 2017-2019. The results of this study indicate that return on assets and debt to assets have a significant effect on firm value. Meanwhile, earnings per share, growth and size have no significant effect on firm value
PRESTASI PENGHEMATAN ENERGI LISTRIK DENGAN TINDAKAN HABITUS PADA RUMAH TINGGAL MAHASISWA TINGKAT TIGA TEKNIK LISTRIK POLINES
Get PDFHarga jual listrik di Indonesia cukup dinamis karena pemerintah melakukan kebijakan pengetatan subsidi listrik. Masyarakat perlu hemat dalam penggunaan energi listrik. Sikap hemat listrik dapat dimulai sejak di lingkungan rumah tangga. Program penghematan listrik untuk kegiatan harian di rumah tinggal mahasiswa tingkat tiga Teknik Listrik Polines telah dilaksanakan. Hasil evaluasi menunjukkan tingkat prestasi hemat energi listrik sebanyak 90 % rumah keluarga mahasiswa berhasil menerapkan program manajemen energi listrik dan dapat menghemat listrik rerata 18 % per-bulan. Sedangkan sebanyak 10 % mahasiswa tingkat tiga Teknik Listrik Polines belum dapat menghemat listrik di rumah keluarga mahasiswa dan keborosan rerata 7,5 % per-bulan. Ada peluang hemat listrik di rumah keluarga mahasiswa setiap bulan sebanyak rerata Rp.32.497,-/bulan atau Rp.389.967,- /tahun.Electricity tariffs in Indonesia are an adaptable prices because the government has implemented a policy of tightening electricity subsidies. People need to be efficient in the use of electrical energy. The attitude of saving electricity can be started in the household environment. The electricity saving program for daily activities in the residences of third-year students of Electrical Engineering at the Semarang State Polytechnic has been implemented. The results of the evaluation show that 90% of student family homes have successfully implemented an electrical energy management program and can save electricity an average of 18% per month. Meanwhile, as many as 10% of third-level students of Electrical Engineering at the Semarang State Polytechnic have not been able to save electricity in the student's family home and the average waste is 7.5% per month. There is an opportunity to save electricity at the student's family home every month on average Rp.32,497,-/month or Rp.389,967,-/year
Pemanfaatan Biogas sebagai Sumber Energi Penghasil Energi Pendinginan, Energi Listrik dan Energi Pemanasan - Studi Fisibilitas
Get PDFWalaupun menjadi salah satu sumber polusi yang cukup tinggi, penggunaan bahan bakar fosil sebagai sumber energi masih menjadi yang dominan jika dibandingkan dengan jenis sumber energi yang lain. Selain itu, permasalahan yang terjadi saat ini adalah produksi bahan bakar fosil tidak sebanding dengan permintaan yang terus meningkat. Guna menurunkan dampak negatif dari penggunaan bahan bakar fosil, penggunaan energi yang ramah lingkungan terus dikembangkan, salah satunya adalah yang digunakan pada penelitian saat ini, yaitu pemanfaatan biogas sebagai sumber energi pendinginan, energi listrik dan energi pemanasan atau yang dikenal dengan trigeneration energy. Metoda yang digunakan adalah dengan cara memanaskan fluida dengan bahan bakar biogas, lalu fluida panas dialirkan ke sistem refrigerasi sistem absorpsi dan sistem pembangkit listrik TEG (thermoelectric generator). Berdasarkan hasil perhitungan, pemanasan fluida menggunakan biogas membutuhkan energi sebesar 615 watt. Kemudian besaran energi ini digunakan untuk sistem pendingin absorpsi dan TEG yaitu berturut-turut 70 dan 397 watt. Sisa energi sebesar 148 watt dapat digunakan untuk energi pemanasan. Ketika energi pemanasan tidak digunakan, maka energi dari fluida panas (615 watt) dapat seluruhnya digunakan atau di maksimalkan untuk pembangkitan energi pendinginan dan energi listrik. Keywords:
Analisa Pengaruh Waktu Inisiasi Pembakaran Terhadap Karakteristik Arang Tempurung Kelapa Menggunakan Alat Tungku Minim Asap dengan Sistem Konsentrasi Asap
Get PDFProses pembuatan arang secara tradisional menghasilkan rendemen yang rendah dan kandungan air yang tinggi sehingga harus dijemur dibawah panas matahari. Sebagian besar proses pembuatan arang dengan cara tradisional dilakukan dengan cara membakar secara langsung tempurung kelapa dan untuk memadamkannya menggunakan air. Tujuan dari penelitian ini adalah mendesain drum kiln dan mensimulasikan aliran panas dari dapur pemanas menggunakan software SOLIDWORKS. Pada penelitian ini juga dipelajari pengaruh waktu inisasi pembakaran tempurung kelapa pada temperatur pemanasan 450 oC terhadap rendemen arang tempurung kelapa dari waktu 2-5 jam pembakaran dan membandingkan dengan cara konvensional. Hasil penelitian menunjukkan, waktu inisiasi optimum diperoleh pada 2 jam proses yang menghasilkan rendemen sebesar 60%. Selanjutnya, proses pembakaran konvensional hanya mengasilkan rendemen 30% dengan waktu proses lebih lama yaitu 7 jam. Peningkatan lama pemanasan menurunkan kadar air dan kadar abu pada arang. Proses pembakaran dengan tungku arang minim asap dengan sistem konsentrasi asap lebih baik dibandingkan pembakaran konvensional. Kualitas arang yang dihasilkan dari pembakaran tungku minim asap dengan sistem konsentrasi asap lebih baik dibanding dengan cara tradisional. Hasil simulasi aliran panas dengan SOLIDWORKS diperoleh karakteristik aliran panas turbulen pada bagian dalam drum kiln dan bagian atas penutup luar
Analisis Kegagalan Poros Track Roller Bearing pada Mesin Pembelah Bambu
Get PDFSplitting merupakan salah satu tahapan proses produksi bambu laminasi. Splitting dilakukan dengan mesin pembelah bambu untuk mengubah batang bambu menjadi bilah-bilah bambu. Dalam proses splitting, komponen booster bergerak maju-mundur di sepanjang rel untuk mendorong bambu yang terletak pada bagian penopang sampai ujung bambu bertumbukan dengan pisau pembelah sehingga batang bambu terbelah menjadi bilah-bilah (bamboo strips). Pada mesin pembelah bambu terdapat track roller bearing yang berfungsi sebagai guide roller. Salah satu komponen penting dalam rangkaian track roller bearing adalah poros. Kasus kegagalan komponen berupa patahnya poros track roller bearing telah dijumpai pada mesin pembelah bambu yang terdapat di sentra kerajinan bambu, Rosse Bambu Yogyakarta. Kerusakan komponen mesin tentu menghambat berjalannya proses produksi bambu laminasi, oleh sebab itu dilakukan analisis kegagalan dalam penelitian ini dengan tujuan untuk mengetahui faktor penyebab kegagalan yang dialami oleh poros track roller bearing pada mesin pembelah bambu sekaligus sebagai upaya antisipasi untuk menghindari terjadinya kasus kegagalan yang serupa. Analisis kegagalan dilakukan dengan melakukan pengujian komposisi kimia material dengan metode Atomic Emission Spectroscopy (AES), pengamatan visual dan pengamatan skala makro terhadap permukaan patahan yang terbentuk, pengujian metalografi untuk mengetahui struktur mikro material poros track roller bearing yang patah, dan pengujian kekerasan Vickers. Permukaan patahan poros tampak terang dan berbentuk granular menunjukkan karakteristik patah getas. Hasil analisis menunjukkan bahwa material poros terbuat dari baja karbon tinggi AISI 1080 yang telah menerima perlakuan quenching dengan nilai kekerasan material sebesar 311,59 HV sehingga material bersifat keras dan getas. Sifat tersebut mengakibatkan poros tidak mampu menahan beban kejut yang diterima saat proses pembelahan bambu berlangsung. Kesimpulan yang diperoleh yaitu kegagalan yang terjadi disebabkan oleh faktor pemilihan material dan perlakuan panas yang dilakukan tidak sesuai untuk aplikasi poros track roller bearing pada mesin pembelah bambu
Rekayasa dan Pembuatan Mesin Pencacah Sampah Organik Dual Function Untuk Mendukung Sistem Konversi Limbah Organik menjadi Biogas
Get PDFIn recent years, domestic carbage become a serious problem since not all waste is managed properly. The organic waste has a potential as a feedstock for biogas production. Before the fermentation process of biogas production, it is necessary to enumerate organic waste with the help of a multi-function chopper. In the present work, dual function machine (chopping and milling process) is designed and fabricated. The machine is driven with a 5.5 HP gasoline engine with a two-way transmission system connecting to each process. The first line transmission system on the chopping with a pulley size of 2 inch diameter, two grooves mounted on the motor and a 3 inch pulley mounted on the chopper axis with a rotation speed of 2400 rpm. The second line transmission system on the milling uses a 12 inch diameter pulley with a rotation of 600 rpm. The test results show that the capacity of the machine was 60 kg/h with 1 cm chopping size
Study of solar power plants as an aerator driver based on the Internet of Things (IoT)
Get PDFThe use of solar power plants is now developing, for example aerator drives with the Internet of Things. The purpose of designing aerators with the Internet of Things is to utilize programming instructions that each command can generate interaction with fellow devices and connect automatically without user intervention, even remotely. This research method begins with the study of literature, manufacture, installation of components, as an analysis carried out testing and data collection. The results of the tests conducted on day 5 include, the best solar radiation intensity power of 886.786 W/m2, the power produced by solar cells of 473.099 W and aerator power of 75.843 W, solar panel efficiency of 14.749%. and PLTS system efficiency of 4.275%. In this test, it was found that the addition of aeration can increase oxygen concentration and pH value of water. Keywords- Aerator, PLTS, Performance