SISTEM KONTROL SUDUT PITCH BILAH TURBIN ANGIN MENGGUNAKAN LOGIKA FUZZY UNTUK VARIABLE SPEED VERTICAL AXIS WIND TURBINE (VAWT)

VAWT (Vertical Axis Wind Turbine) is a turbine that has an upright mechanical structure with its blades rotating toward a perpendicular z-axis. Based on the experimental results, it is found that there is a relationship between the rotational speed of turbine that rotates generator with the output voltage and power. Thus, it is necessary to control the wind turbine speed so it can rotate according to the set point to be achieved. The contribution of this research is the development of a Fuzzy logic-based control system to control the speed of VAWT turbine where the speed of turbine is used as feedback. To design a Fuzzy rule base, the characteristics of the wind turbine’s response to wind speed are investigated first. Then Fuzzy logic-based controller is created and implemented. To test the effectiveness of the Fuzzy controller made, the implementation is carried out on a VAWT turbine while the simulation is applied to PMSG model using wind turbine through Simulink/Matlab. Based on simulation and experiment results, the performance of the control system using Integral Absolute Error (IAE) for each turbine speed set point value (35, 45, 85, and 100 RPM), it is found that for a small set point value, the IAE value will be larger than higher setpoints. The percentage of the average IAE value for the simulation is 10.25% higher than the experiment. It further shows that the control turbine speed at low speeds is relatively more difficult than at higher speeds.Turbin angin sumbu vertikal atau VAWT (Vertical Axis Wind Turbine) merupakan turbin angin yang memiliki struktur mekanik tegak ke atas dengan bilah-bilah turbin yang berputar terhadap sumbu-z tegak lurus. Berdasark an hasil eksperimen diperoleh bahwa terdapat hubungan antara kecepatan putaran turbin yang memutar generator dengan keluaran tegangan dan daya yang dihasilkan, sehingga diperlukan upaya mengendalikan kecepatan turbin angin agar dapat berputar sesuai setpoin yang ingin dicapai. Kontribusi dari penelitian ini berupa pengembangan sistem kontrol berbasis logika Fuzzy untuk mengendalikan kecepatan turbin VAWT dengan hanya menggunakan umpan balik berupa kecepatan turbin angin. Hal ini berbeda dengan penelitian sebelumnya dimana kecepatan angin dan keluaran daya dijadikan sebagai umpan balik. Untuk mengetahui karakteristik dari kecepatan turbin dan keluaran tegangan, serta hubungan antara kecepatan turbin dan kecepatan angin dengan variasi sudut pitch bilah, maka pengujian dilakukan dalam skala laboratorium dengan menggunakan blower. Untuk merancang rule base (aturan) Fuzzy, maka karakteristik dari respon turbin angin terhadap kecepatan angin diteliti terlebih dahulu. Kemudian kontroller berbasis logika Fuzzy dibuat dan diimplementasikan. Untuk menguji efektivitas kontroller Fuzzy yang dibuat, maka implementasi dilakukan pada turbin VAWT sedangkan simulasi diterapkan pada model PMSG turbin angin melalui Simulink/Matlab. Berdasarkan hasil pengujian melalui simulasi dan eksperimen dengan mengukur kinerja respon sistem kontrol menggunakan Integral Absolut Error (IAE) untuk masing-masing nilai setpoin kecepatan turbin (35, 45, 85, dan 100 RPM) diperoleh bahwa untuk nilai setpoin kecil maka nilai IAE akan semakin besar dibandingkan setpoin yang lebih tinggi. Persentase nilai rata-rata IAE untuk simulasi adalah 10,25% lebih tinggi dibandingkan dengan eksperimen. Hal ini kemudian menunjukkan bahwa pengendalian kecepatan turbin pada kecepatan rendah relatif lebih sulit dibandingkan dengan kecepatan turbin lebih tinggi

PEMODELAN BATERAI AIR GARAM DAN PENGUJIAN SALINITAS ELEKTROLIT BERBASIS PLC

One of the technologies of this power source is a brine battery. In this study, testing the effect of electrolyte salinity levels on the performance of brine batteries with two different types of electrodes  was carried out, namely using magnesium anodes and aluminum anodes. In its cathode part used inert metal or carbon. Variations are carried out on the electrolyte solution used in the form of brine containing Na and Cl ions as electron conductors as well as reductors. Because the reaction of the brine battery system is relatively complex, a study was conducted in this study to see the effect of electrolyte salinity levels (27, 37, and 47 ppt) on the dc voltage produced. The measured parameters include the value of the dc voltage and the resulting current as well as the change in the salinity level after operating for a certain period of time. Tests were performed on batteries to drain the 0.47Ω resistor load operating for 24 hours non-stop where the parameter measurement setup was performed automatically using a PLC. The values of such parameters are monitored and recorded during 24-hour operation. Based on the results of measurements, the average energy capacity that can be used in Mg electrode cells is 17.6% of the total energy generated from the reaction of battery cells, then the average usable battery capacity on the Al electrode cell is 2.6% of the total energy produced.Baterai adalah bagian dari elektrokimia yang sudah pada kehidupan masyarakat dunia. Isu kerusakan lingkungan merupakan dorongan untuk terus mengembangkan teknologi sumber tenaga yang komponen pendukungnya ramah lingkungan dan mudah didapatkan. Reaksi redoks pada sel yang berisi dua elektroda beda potensial, jika dihubungan dengan elektrolit dan beban sudah mampu membangkitkan tegangan dc. Pada pengujian ini kombinasi elektroda baterai menggunakan anoda logam magnesium dan logam aluminium, sedangkan katoda adalah logam inert atau carbon. Elektrolitnya adalah air garam yang mengandung ion Na dan Cl sebagai penghantar elektron sekaligus air sebagai reduktor. Yang menjadi fokus pengujian adalah tingkat salinitas elektrolitnya, dimana dibagi tiga tingkatan 27 ppt, 37 ppt dan 47 ppt. Parameter baterai adalah perubahan nilai tegangan, arus dan salinitas. Dilakukan masing-masing 3 kali pengujian terhadap masing-masing kombinasi elektroda. Hasilnya untuk elektroda magnesium, untuk salinitas 47 ppt terukur Voc=1,5 V dan Isc=1,52 A; sedangkan 37 ppt terukur Voc=1,454 V dan Isc=0,702 A; kemudian 27 ppt terukur Voc=1,433 V dan Isc = 0,625 A. Kemudian untuk elektroda aluminium untuk salinitas 47 ppt terukur Voc=0,898 V dan Isc=0,197 A; sedangkan 37 ppt terukur Voc=0,798 V dan Isc=0,184 A; kemudian 27 ppt terukur Voc=0,684 V dan Isc=0,125 A. Jadi hipotesa awal penelitian bahwa semakin tinggi tingkat salinitas elektrolit maka tegangan sel baterai ) semakin besar, untuk Voc dan Isc adalah benar. Untuk uji performa sel baterai air garam selama 24 jam dengan diberikan beban Resistor 0,47 Ω, dengan menganalisa perubahan nilai tegangan dan salinitas didapatkan bahwa hipotesa tidak benar

PEMANFAATAN PEMBANGKIT LISTRIK HYBRID DALAM MENDUKUNG ELEKTRIFIKASI DI KAWASAN JAVAN LANGUR CENTRE KOTA BATU JAWA TIMUR

Javan Langur Center (JLC) is a Javan Langur rehabilitation center located approximately 10 km from the center of Batu city, East Java. To support activities at this rehabilitation center, electrical energy is needed, especially to meet the needs of lighting facilities and the operation of a primate baby incubator machine. To date, no electricity distribution network from the State Electricity Company (PLN) has entered the area. To meet these electricity needs, the electricity supply is obtained from a gen-set owned by residents which is approximately 2 km from the JLC. This Community Service Program was carried out between February and August 2020 with activities in the form of the construction of a hybrid power plant to meet the electricity needs of the JLC. The hybrid power plant that is installed is a combination of pico-hydro power plant technology (PLTPH) and solar power plant (PLTS). During the implementation of the program, there were two activity partners who played an active role, namely The Aspinall Foundation Indonesia Program (JLC manager) and the Javan Lutung Conservation Community, with a total of about 10 personnel. The result of this community service program is the installation and operation of a hybrid power generation system, which consists of a 300-watt pico-hydro power plant and a 200-watt peak solar power plant. With this hybrid power plant, the electricity needs in the JLC area for lighting and operating the Lutung baby incubator machine, with a total power of 180 watts, can be met. In addition, to maintain the sustainability of the operation and maintenance of the hybrid power plant, a transfer of knowledge and skills has been carried out to partners, namely The Aspinal Foundation Indonesia Program and the Javan Lutung Conservation Community. --- Javan Langur Center (JLC) adalah pusat rehabilitasi Lutung Jawa yang terletak lebih kurang 10 km dari pusat kota Batu, Jawa Timur. Untuk menunjang kegiatan di pusat rehabilitasi ini, energi listrik sangat dibutuhkan, terutama untuk memenuhi kebutuhan fasilitas penerangan dan pengoperasian mesin inkubator bayi primata. Sampai saat ini, belum ada jaringan distribusi listrik dari Perusahaan Listrik Negara (PLN) yang masuk di kawasan ini. Untuk memenuhi kebutuhan listrik tersebut,  pasokan energi listrik didapatkan dari gen-set milik warga yang jaraknya kurang lebih 2 km dari JLC. Program Pengabdian Kepada Masyarakat ini dilaksanakan antara bulan Pebruari sampai bulan Agustus 2020 dengan kegiatan berupa pembangunan pembangkit listrik hybrid untuk memenuhi kebutuhan listrik di JLC. Pembangkit listrik hybrid yang dipasang merupakan penggabungan teknologi pembangkit listrik tenaga pikohidro (PLTPH) dan pembangkit listrik tenaga surya (PLTS). Selama pelaksanaan program, ada dua mitra kegiatan yang berperan aktif, yakni The Aspinall Foundation Indonesia Program (pengelola JLC) dan Komunitas Konservasi Lutung Jawa, dengan total personel sekitar 10 orang. Hasil program pengabdian kepada masayarakat ini berupa pemasangan dan pengoperasian sistem pembangkit tenaga listrik hybrid, yang terdiri atas pembangkit listrik tenaga piko hidro berkapasitas 300 watt dan pembangkit listrik tenaga surya berkapasitas 200 watt peak. Dengan adanya pembangkit listrik hybrid ini, maka kebutuhan listrik di area JLC untuk penerangan dan pengoperasian mesin inkubator bayi Lutung, dengan total daya 180 watt dapat terpenuhi. Selain itu, untuk menjaga keberlangsungan pengoperasian dan pemeliharaan pembangkit tenaga listrik hybrid tersebut, telah dilakukan transfer pengetahuan dan keterampilan kepada pihak mitra kerja, yakni The Aspinal Foundation Indonesi Program dan Komunitas Konservasi Lutung Jawa

PEMANFAATAN SUMBER DAYA AIR UNTUK PEMBANGKIT LISTRIK TENAGA PIKO HIDRO DI KAWASAN COBAN TARZAN KECAMATAN JABUNG KABUPATEN MALANG

The natural tourist area of ​​Coban Tarzan waterfall, Jabung District, Malang Regency, is ± 25 km from Malang City. Until now, the fulfillment of electricity needs is obtained from generator sets owned by residents. This area has not yet received an electricity supply from the State Electricity Company (PLN). To overcome these problems, one way that can be done is to utilize existing water resources in the area as a source of electrical energy through the application of a pico-hydro power plant system. The purpose of this community service program is to build a pico-hydro power plant in the natural tourist area of ​​the Coban Tarzan waterfall with a generating capacity of 270 watts. This activity starts from April to November 2021. In carrying out this community service program, there are two activity partners, namely the Coban Tarzan Waterfall Natural Tourism Area Manager and the Sukopuro Forest Management Resort (RPH), with 6 personnel. The method used in the community service program includes 2 aspects, namely the physical aspect in the form of the construction of a pico-hydro power plant and the non-physical aspect in the form of transferring knowledge and skills to work partners regarding the operation and maintenance of the power plant. The results of this community service program are installing and operating a pico-hydro power plant with a capacity of 270 watts. With this power plant, the electricity needs in the Coban Tarzan Waterfall Natural Tourism Area can be met with a total power of around 150 watts. For a pico-hydro power plant to operate according to its capacity, it is necessary that the operation and maintenance of system equipment be carried out correctly and on a scheduled basis.  ---  Kawasan wisata alam air terjun Coban Tarzan, Kecamatan Jabung, Kabupaten Malang berjarak ± 25 km dari Kota Malang. Sampai saat ini, pemenuhan kebutuhan listrik didapatkan dari genset (generator set) milik warga dikarenakan kawasan ini belum mendapatkan pasokan listrik dari Perusahaan Listrik Negara (PLN). Untuk mengatasi permasalahan tersebut, salah satu cara yang dapat dilakukan adalah dengan memanfaatkan sumber daya air yang ada di kawasan tersebut sebagai sumber energi listrik melalui penerapan teknologi pembangkit listrik tenaga piko hidro. Tujuan program pengabdian kepada masyarakat ini adalah untuk membangun suatu pembangkit listrik tenaga piko hidro di kawasan wisata alam air terjun Coban Tarzan dengan kapasitas pembangkit sebesar 270 watt. Kegiatan ini dimulai  pada bulan April sampai bulan November 2021. Dalam menjalankan program pengabdian kepada masyarakat ini, terdapat dua mitra kegiatan, yakni Pengelola Kawasan Wisata Alam Air Terjun Coban Tarzan dan Resort Pemangkuan Hutan (RPH) Sukopuro dengan total jumlah personel 6 orang. Metode yang dilakukan dalam program pengabdian kepada masyarakat meliputi 2 aspek, yakni  aspek fisik berupa pembangunan pembangkit listrik tenaga piko hidro dan aspek non fisik berupa transfer pengetahuan dan keterampilan kepada pihak mitra kerja mengenai pengoperasian dan perawatan pembangkit listrik tersebut. Hasil program pengabdian kepada masayarakat ini berupa pemasangan dan pengoperasian pembangkit listrik tenaga piko hidro berkapasitas 270 watt. Dengan adanya pembangkit listrik ini, maka kebutuhan listrik di kawasan Kawasan Wisata Alam Air Terjun Coban Tarzan dapat terpenuhi dengan total daya sekitar 150 watt. Agar pembangkit listrik tenaga piko hidro dapat beroperasi sesuai dengan kapasitasnya, maka perlu pengoperasian dan perawatan terhadap peralatan sistem haruis dilakukan secara benar dan terjadwal

Atomic Mineral Characteristics of Indonesian Osteoporosis by High-Resolution Inductively Coupled Plasma Mass Spectrometry

Clinical research indicates that negative calcium balance is associated with low bone mass, rapid bone loss, and high fracture rates. However, some studies revealed that not only calcium is involved in bone strengthening as risk factor of fracture osteoporosis. Thus, in this report, the difference of metallic and nonmetallic elements in osteoporosis and normal bones was studied by high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). The influence of these elements on bone metabolic processes is also discussed. Inclusion criteria of bone samples consist of postmenopausal woman, trabecular bone fracture, normal and osteoporosis BMD value, and no history of previous disease. The results showed that the concentration of B, Al, S, V, Co, Mo, Te, Ba, La, Ni, As, and Ca/P ratio is higher in osteoporosis than normal. These atomic minerals have negative role to imbalance between bone resorption and bone formation activity. Conversely, concentrations of Na, Mg, P, K, Ca, Cr, Pd, Ag, Mn, Fe, Cu, Zn, Rb, Sr, Pb, and Se are lower in osteoporosis than in normal bones. Among these atoms, known to have important roles in bone structure, we found involvement of atomic mineral and calcium which are considerable to contribute to osteoporotic phenomena

Pengaruh Panel Surya Bentuk Flat dan Flexy Terhadap Daya Pengisian Baterai Sepeda Listrik

ABSTRAK Perkembangan dunia global dan isu emisi nol (zero emmision) telah menjadi blue print energi dari semua negara. Salah satunya adalah terobosan teknologi transportasi yang ramah lingkungan. Dalam beberapa tahun terakhir, teknologi kendaraan listrik telah berkembang pesat. Selain dari desain dan performansi, konsep hybrid panel surya dengan kendaraan listrik juga banyak dilakukan oleh banyak peneliti. Oleh karena itu, penelitian ini bertujuan untuk menganalisis performansi pengisian baterai pada sepeda listrik yang dihasilkan oleh dua bentuk panel surya yang berbeda (flat dan flexy). Metode penelitian true experimental dilakukan dengan monitoring data dari sensor tegangan, arus, dan daya listrik yang dihasilkan panel surya. Sedangkan radiasi matahari diukur dengan solar power meter. Daya listrik yang dihasilkan panel surya digunakan untuk pengisian baterai sepeda listrik. Hasil penelitian menunjukkan bahwa pada radiasi matahari maksimum terjadi pada jam 13.00 WIB sebesar 1008 W/m2. Panel surya bentuk flat menghasilkan daya listrik sebesar 58,94 Wh Sedangkan bentuk flexy sebesar 44,87 Wh. Sehingga panel surya bentuk flat lebih effisien dibandingkan dengan flexy untuk pengisian baterai pada sepeda listrik.Kata kunci: panel surya flat, panel surya flexy, daya pengisian, baterai, sepeda listrikABSTRACTThe development of the global world and the issue of zero emissions has become an energy blueprint for all countries. One of them is the breakthrough of environmentally friendly transportation technology. In recent years, electric vehicle technology has developed rapidly. Apart from design and performance, the concept of hybrid solar panels with electric vehicles is also being carried out by many researchers. Therefore, this study aims to analyze the charging performance of electric bicycle batteries produced by two different forms of solar panels (flat PV and flexy PV). The true experimental research method was carried out by monitoring data from sensors of voltage, current, and electric power generated by solar panels. While solar radiation is measured with a solar power meter. The electricity generated by the solar panels is used to charge the electric bicycle battery. The results showed that the maximum solar irradiation occurred at 01.00 pm at 1008 W/m2. Flatform solar panels produce electricity of 58.94 Wh while flexible form 44.87 Wh. Therefore, flat solar panels are more efficient than flexy for charging batteries on electric bicycles.Keywords: solar panel, flat PV, flexy PV, charging power, battery, electric bicycl

A Novel Single-Stage PWM Microinverter Topology Using Two-Power Switches

This paper presents a novel single-stage microinverter topology using only two-power switches. The number of components count are directly proportional to the power losses, weight, cost and complexity of the design. Nowadays, conventional Microinverter without transformer having minimum of six power switches, while only three power switches involved in a Microinverter structure with the presence of a transformer. Thus, this paper proposed a novel Microinverter topology with only two-power switches to convert DC-voltage from Photovoltaic (PV) module to an AC-output. Modes of operation and current flow during each cycle are being explained. Variation of modulation index, irradiance and temperature of the PV module, the switching frequency and harmonic content of the proposed Microinverter are being analysed. A simulated model of Microinverter topology, employed only two power switches with a standard Unipolar Sinusoidal Pulse Width Modulation (SPWM) having 0.85% harmonic percentage; able to inject current to the load; have been successfully built and demonstrated through simulation based on MATLAB/Simulink, thus provide theoretical validation for further researc

Pengembangan Manajemen Produksi dan Pemasaran Usaha Keripik Singkong Di Desa Dongos Kabupaten Jepara

The impact of Covid-19 was felt from various sectors including MSMEs. One of them is Kripik Singkong Lancar Mandiri MSMEs in Dongos Village. The problem faced by partners is the monotony of production and management systems for selling goods. The purpose of this community service is to increase understanding and application of science and technology in society (mechanization, IT, and management) and to increase competitiveness (increasing the quality, quantity, and value of resources). The method of implementing community service includes (1) the preparation stage, the activities carried out are problem identification and data collection; (2) the implementation stage, the activities carried out are the process of training and mentoring; (3) the evaluation stage; and (4) preparation of reports stage. The results of this community service show that there is an increase in understanding and application of science and technology in society (mechanization, IT, and management) and there is an increase in competitiveness (increasing the quality, quantity, and value of resources)

The effects of different ph and salinities on growth rate and carrageenan yield of gracilaria manilaensis

The high demand of seaweed for their polysaccharide namely carrageenan leads to the commercial production of carrageenophytes through mariculture. Based on literatures it is well documented that growth rate and carrageenan yield depend on environmental factors such as salinity, pH, temperatures, light intensity and water movement. In this study, growth rate and carrageenan yield of Gracilaria manilaensis, a red seaweed, was determined at different pH and salinities. G. manilaensis was cultured under laboratory conditions in a 500 mL flask at different salinities (15 psu, 20 psu and 25 psu ) and pH (7.6, 7.8, and 8.0) for 21 days. At the end of experiment, the growth rate was determined followed by carrageenan analysis. From the analysis, growth rate was highest at salinity of 15 psu and pH 7.6 with 1.3 ± 0.2 % day-1.For carrageenan analysis, the seaweed was air dried for about a week until it reached a constant weight. Farmed G. manilaensis was used as control and carrageenan yield was determined from farmed G. manilaensis. It gives yield of 50.2 ± 10.9 %. For carrageenan yield analysis, the highest value was demonstrated at salinity of 25 psu and pH 8.0 with 91.7± 14.4 %. Result shows that carrageenan yields from G. manilaensis under laboratory conditions are higher compared to farmed Gracillaria. This indicates that the quality of G. manilaensis in term of carrageenan content can be optimized under certain growth conditions. This is important as this species has the potential to be commercialized for pharmaceutical and food industries

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection