The economic value of patchouli oil is largely determined by its quality. The research objective was to study the quality of patchouli oil in North Kolaka. Quality analysis based on physical chemical properties of patchouli oil. The quality of patchouli oil (sample 1a and 1b) products from the distillation industry in North Kolaka has fulfilled most of the specifications of SNI quality standards. Patchouli oil (Sample 2), obtained by processing patchouli plant samples from North Kolaka by good and correct postharvest and refining methods, the quality has met all SNI quality specifications. Patchouli oil in North Kolaka has good quality potential and can meet Indonesian patchouli oil quality specifications.

Media pembelajaran sangat penting, terutama untuk mengenalkan dunia industri pada pendidikan kejuruan. Proyek ini bertujuan untuk merancang dan mendemonstrasikan model ruang penyimpanan makanan berbasis programmable logic controller (PLC) untuk meningkatkan pemahaman siswa SMK tentang aplikasi instrumentasi dan automasi di industri. PLC, sebagai perangkat kontrol utama dalam model, dapat mengontrol pintu dan kelembapan ruang penyimpanan. Komponen lain dalam model ini meliputi catu daya, sensor kelembapan, pemanas, kipas, dan pintu. Proyek dilaksanakan dengan penyampaian materi melalui presentasi, praktek pemrograman, dan mengoperasikan PLC secara berkelompok. Peserta diajarkan cara memprogram PLC berbasis diagram tangga menggunakan perangkat lunak Zelio Soft 2. Pemahaman peserta, siswa SMK N 2 Bandar Lampung diukur untuk mengetahui tingkat ketercapaian proyek. Hasil menunjukkan bahwa pemahaman peserta tentang aplikasi instrumentasi dan automasi di industri meningkat rata-rata 64% dari sebelum pelatihan dilaksanakan.   Learning media is very important, mainly to introduce the industrial world in vocational education. The project purposed to design and demonstrate a programmable logic controller (PLC) based food storage room model to increase the comprehension of SMK students about instrumentation and automation applications in industry. PLC, as the main control device in the model, can control the door and the humidity of the storage room. Other components in the model include the power supply, humidity sensor, heater, fan, and door. The project was carried out by delivering material through presentations, practising programming, and operating PLC in groups. Participants were taught how to program a ladder diagram-based PLC using Zelio Soft 2 software. The comprehension of the participants, students of SMK N 2 Bandar Lampung, was measured to determine the level of project achievement. The results revealed that the comprehension of participants about instrumentation and automation applications in the industry increased by an average of 64% from before the training was carried out.

Research on the characterization of gold ore from Babakan Loa sub-district and studies of leaching in cyanide solution has been carried out. This research was conducted to determine the characteristics of gold ore from Babakan Loa and the leaching behavior in cyanide solution. The preparations carried out were crushing and grinding to obtain several size fractions. The ore characterization was carried out through XRD, XRF, SEM-EDX, and wet chemical analysis. XRD analysis results show that the main mineral phases are quartz, hematite, goethite, kaolinite, montmorillonite, and berlinite. The main constituents of the ore were Si (60.96%), Fe (10.71%), K (5.47%), and Al (19.53%). The Au content was 7.8 ppm, and the results of SEM-EDX analysis show that the gold grain size is smaller than 10µm. The leaching process showed that the highest percent gold extraction data of 92.7% was obtained in experiments with 1000 ppm sodium cyanide concentration, 10% solids percent, and 104-149µm grain size. Increasing the percentage of solids and the reduction in grain size led to a decrease in the percentage of gold extraction. The clay content was suspected to be the cause of the ineffectiveness of the leaching process in this study.

Research on the extraction of gold ore from Pesawaran, , Lampung, Indonesia, was carried out using the agitation leaching method in cyanide solution. This study aimed to obtain information on the use of conventional cyanidation methods for extracting gold from the Pesawaran gold ore. The ore preparation was carried out in the form of crushing, grinding and sieving to obtain samples with fraction sizes of -60 + 100 mesh, -100 +150 mesh, -150 + 200 mesh and -200 mesh. The ore characterization was performed using XRD, XRF, SEM-EDX, and wet chemical analysis. The XRD analysis showed that the main mineral phases were silica, hematite, aluminium hydroxide and orthoclase. The major constituents of the ore were Si (53,628%), Fe (15,996%), K (19,744%) and Al (8,045%). The Au content was determined by wet chemical analysis and was found to be 9.67 ppm. The experimental results show that the highest percentage of gold extraction of 83.33% was obtained using sodium cyanide at a concentration of 1000 ppm, a percent solids of 40% and a grain size of 200 mesh. Higher gold extraction was not achieved despite the use of a high cyanide concentration was probably because the remaining gold was not properly liberated. The results of SEM-EDX analysis showed that the gold grain size was <20 µm, while the grinding was performed only to a sieve size of -200 mesh (74 µm).