The development of low viscosity insulating liquids derived from natural esters is conducted in our laboratory. Nine monoesters, i.e., methyl myristate, ethyl myristate, isopropyl myristate, methyl palmitate, ethyl palmitate, isopropyl palmitate, methyl stearate, ethyl stearate, and isopropyl stearate were synthesized from alcohols and saturated fatty acids. Treatments were performed to reduce water and acid contents and improve the oxidation stability of the monoesters. Some fundamental properties, such as breakdown voltage, kinematic viscosity, density, water content, acidity, and oxidation stability, were tested before and after treatments. The results are evaluated based on the international electrotehnical commission (IEC) standard specifications for low-viscosity monoesters derived from natural esters, IEC 62770. Except for the water content, all other properties have good compliance with the standard. The treatments reduced the water content significantly, but the values are still slightly higher than that specified by the standard.

Makalah ini membahas hasil eksperimen terhadap sejumlah parameter Etil ester sebagai minyak isolasi. Tiga macam Etil ester, yaitu Etil miristat, Etil palmitate dan Etil stearate, dibuat melalui reaksi esterifikasi antara Etil alcohol dan asam miristat, asam palmitate dan asam stearat. Sejumlah parameter listrik, fisika dan kimia seperti tegangan tembus, viskositas kinematic, massa jenis, kadar air, angka keasaman dan stabilitas oksidasi diuji dan dibandingkan dengan standar spesifikasi ASTM D 6871. Hasil pengujian menunjukkan bahwa tegangan tembus semua sampel Etil ester lebih tinggi dari nilai minimal yang dipersyaratkan oleh standar. Viskositas kinematic, massa jenis dan angka keasaman semua sampel lebih rendah dari nilai maksimal yang ditolerir oleh standar. Angka peroksida semua sampel, yang digunakan sebagai indikator stabilitas oksidasi, lebih rendah dari minyak mineral. Kadar air merupakan satu-satunya parameter yang masih lebih tinggi dari nilai yang diperbolehkan oleh standar.

To identify the fault, wavelet method is used in solving complex protection problems. This study uses a new approach, namely the wavelet multi resolution analysis method with its application where multi resolution analysis works to analyze signals at different frequencies with the same resolution. In this study, the classification of fault types that occur in the 150 kV transmission line quickly and accurately is carried out using the wavelet multi resolution analysis method. This research is included in applied research and was designed using computer simulation software, namely ATP and MATLAB. The data transmission system used is the Maninjau Hydroelectric Power Plant transmission line to Pauh Limo Substation. The modeled transmission system is given 1-phase to ground, 2-phase to ground, 2- phase, 3-phase and lightning faults. To determine the accuracy of this classification, the fault is varied according to the distance and impedance of the disturbance. From the analysis of the simulation results and calculations, based on the wavelet multi resolution analysis method used in fault classifying, the average value of the approximation coefficient used to classify the type of fault is obtained. Based on the results of the study, it can be said that all types of fault analyzed in this study have met the classification requirements using the wavelet multi resolution analysis method

Sebagian besar masyarakat yang hidup diperkotaan mengalami peningkatan kebutuhan dalam hal pangan. Salah satu kegiatan yang bisa memanfaatkan lahan dan sumber daya di perkotaan adalah urban farming. Salah satu contohnya yaitu Ekowisata Sungkai Green Park di Nagari Lambung Bukit Kecamatan Pauh Padang yang memiliki berbagai macam jenis tanaman yang sangat bermanfaat. Namun disebabkan tanaman yang banyak dan bervariasi, petani mengalami kesusahan dalam hal pemeliharaan tanaman. Kegiatan bertujuan untuk mengklasifikasikan antara gulma dan tanaman, guna mempermudah petani dalam perawatan tanaman. Metode yang akan diterapkan menggunakan machine learning dengan image processing untuk memisahkan gulma dan tanaman yang dapat mengurangi pekerjaan manual secara visual. Analisis gambar mendeteksi secara akurat daerah yang teridentifikasi gulma. Setiap gambar memiliki pola dan distribusi spasial yang berbeda dan mampu dideteksi menggunakan Teknik GLCM. Teknik ini merepresentasikan hubungan antara dua pixel yang bertentangan pada citra. Secara keseluruhan citra diambil menggunakan webcam yang diposisikan vertikal terhadap tanaman sampel pada kondisi low brightness sehingga dapat diproses dengan akurat dalam machine learning. Fitur GLCM ini mampu mengekstrak citra untuk memisahkan gulma dan tanaman dengan menggunakan matriks tekstur dari citra. Output dari matriks berupa parameter mean, skewness, kurtosis, entropy, contrast, dan energy. Parameter tersebut digunakan untuk mendapatkan value pada tanaman sehingga gulma dapat dibedakan dari tanaman. Hasil kegiatan ini dapat memberikan informasi lebih awal kepada petani untuk segera melakukan pemeliharaan tanaman.

To identify the fault, wavelet method is used in solving complex protection problems. This study uses a new approach, namely the wavelet multi resolution analysis method with its application where multi resolution analysis works to analyze signals at different frequencies with the same resolution. In this study, the classification of fault types that occur in the 150 kV transmission line quickly and accurately is carried out using the wavelet multi resolution analysis method. This research is included in applied research and was designed using computer simulation software, namely ATP and MATLAB. The data transmission system used is the Maninjau Hydroelectric Power Plant transmission line to Pauh Limo Substation. The modeled transmission system is given 1-phase to ground, 2-phase to ground, 2- phase, 3-phase and lightning faults. To determine the accuracy of this classification, the fault is varied according to the distance and impedance of the disturbance. From the analysis of the simulation results and calculations, based on the wavelet multi resolution analysis method used in fault classifying, the average value of the approximation coefficient used to classify the type of fault is obtained. Based on the results of the study, it can be said that all types of fault analyzed in this study have met the classification requirements using the wavelet multi resolution analysis method