Hasil Pencarian  ::  Simpan CSV :: Kembali

"Sand control issues in wells can result from improper completion or changes in reservoir properties. Covering all aspects of the topic, this volume shows how methods such as reducing drag forces and mechanical sand bridging can reduce the problems that arise. "

"Kebutuhan pelumas terus meningkat Namun saat ini ketersediaan minyak bumi semakin menipis karena kebutuhan yang terus meningkat. Selain itu, pelumas berbahan dasar minyak bumi memiliki pengaruh negatif terhadap lingkungan karena memiliki sifat yang negatif diantaranya adalah non-renewable, tidak ramah lingkungan dan beracun. Pelumas sintetis merupakan bahan kimia dengan karakteristik lebih baik dibandingkan pelumas mineral dan nabati. Pelumas sintetik terbentuk dari senyawa kimia dengan spesifikasi berkualitas dan dirancang melalui proses sintetik untuk mendapatkan pelumas dengan karakteristik yang spesifik dan sesuai yang diinginkan. Sintesis Pelumas Berbasis Ester dapat dilakukan dengan proses oligomerisasi, esterifikasi dan separasi. Penelitian ini akan menjelaskan mengenai sistem pengendalian proses separasi pada perancangan pabrik Pelumas Berbasis Ester untuk menjaga kestabilan proses produksi pada sebuah pabrik. Pada penelitian ini proses yang akan dikendalikan adalah proses separasi asam n-heptanoat untuk mendaur ulang zat antara yang digunakan untuk memproduksi senyawa Pelumas Berbasis Ester. Pengendalian yang digunakan adalah pengendalian Proporsional Integral (PI) dengan menggunakan metode Ziegler Nichols, Lopez dan Autotuner. Parameter kinerja pengendali yang diperhitungkan menggunakan metode IAE (Integral Absolute Error), ISE (Integral Squared Error) dan ITAE. (Integral of Time Multiplied by Absolute Error). Pada penelitian ini penyetelan pengendalian optimum dicapai dengan menggunakan metode Autotuner dan root mean squared (RMS) terendah didapatkan dengan metode Solver.

---

The need for lubricants continues to increase. However, currently the availability of petroleum is dwindling due to the ever-increasing need. In addition, petroleum-based lubricants have a negative impact on the environment because they have negative properties, including non-renewable, not environmentally friendly and toxic. Synthetic lubricants are chemicals with better characteristics than mineral and vegetable lubricants. Synthetic lubricants are formed from chemical compounds with quality specifications and are designed through a synthetic process to obtain lubricants with specific and desired characteristics. Synthesis of Ester Based Lubricants can be carried out by oligomerization, esterification and separation processes. This study will explain the separation process control system in the design of an Ester-Based Lubricant factory to maintain the stability of the production process in a factory. In this study the process to be controlled is the n-heptanoic acid separation process to recycle the intermediates used to produce Ester-Based Lubricant compounds. The control used is the Integral Proportional (PI) control using the Ziegler Nichols, Lopez and Autotuner methods. The controller performance parameters are calculated using the IAE (Integral Absolute Error), ISE (Integral Squared Error) and ITAE methods. (Integral of Time Multiplied by Absolute Error). In this study the optimum control setting was achieved by using the Autotuner method and the lowest root mean squared (RMS) was obtained by the Solver method."

"Telah dilakukan penelitian tentang jasa ekosistem pengendalian hama serangga oleh burung terhadap bibit tanaman kelapa sawit di FMIPA UI. Tujuan dari penelitian ini adalah untuk menganalisis spesies burung insektivora yang memberikan jasa ekosistem pengendalian hama serangga kepada bibit tanaman kelapa sawit di FMIPA UI. Penelitian dilakukan dengan mengelompokan 10 bibit kelapa sawit menjadi 2 kelompok dengan perlakuan yang berbeda, yaitu perlakuan bird exclosure dan perlakuan kontrol. Setelah itu, dipilih 15 helai daun secara acak pada tiap bibitnya, baik yang sempurna maupun tidak, dan diberikan tanda menggunakan spidol permanen. Tiap daun yang sudah diberi tanda difoto secara digital, dan tingkat herbivora untuk tiap bibit dihitung berdasarkan proporsi rata-rata luas helai daun yang hilang per anak daun per hari. Luas helai daun dihitung dengan perangkat lunak ImageJ. Pengamatan burung dilakukan menggunakan metode point count selama 3 minggu waktu penelitian. Data yang didapat disusun ke dalam tabel, dan dilakukan hitung uji untuk hasil analisis. Analisis perbedaan tingkat herbivori perlakuan bird exclosure dan control dilakukan dengan menggunakan Uji U. Analisis korelasi antara jumlah individu spesies burung dan tingkat herbivori dihitung menggunakan analisis non-parametrik Spearman's Rank. Hasil menunjukkan bahwa ditemukan 6 spesies burung, antara lain Gereja eurasia (Passer montanus), Walet linci (Collocalia linchi), Cucak kutilang (Pycnonotus aurigaster), Nectarinidae, Tekukur biasa (Streptopelia chinensis), serta Cinenen jawa (Orthotomus sepium) dan 2 di antaranya adalah insektivora, yaitu Walet linci (Collocalia linchi) dan Cinenen jawa (Orthotomus sepium) . Tingkat herbivori bibit kelapa sawit kontrol berkisar pada nilai 0,005 sampai 0,303, dan tingkat herbivori pada kelapa sawit bird exclosure berkisar pada nilai 0,013 sampai 0,295. Hasil uji U menunjukkan tidak ada perbedaan nyata antara tingkat herbivori bird exclosure dan kontrol, dan hasil uji korelasi Spearman menunjukkan bahwa tidak ada korelasi kuat antara tingkat herbivori dengan jumlah individu untuk semua spesies burung.

---

A Research about the ecosystem services of controlling insect pests by birds on oil palm seedlings at FMIPA UI has been conducted. The purpose of this research is to analyze insectivore bird species’ that provide insect pest control to oil palm experimental seedlings at FMIPA UI. The research was done by grouping 10 experimental palm oil seeds into 2 groups with different treatments, namely bird exposure treatment and control treatment. After that, 15 leaves were randomly selected from each seedling, whether perfect or not, and marked using a permanent marker. Each tagged leaf was digitally photographed, and the herbivory level for each seedling was calculated based on the average proportion of leaf area lost per leaflet per day. Leaf blade area was calculated using ImageJ software. Bird observations were carried out using the point count method during the 3 weeks of research. The data obtained was arranged into a table, and an unique test was calculated for the results of the analysis. Analysis of the difference of herbivory rate in the bird exclosure treatment was done by using the U Test. Correlation analysis between the number of individual bird species and the level of herbivory was calculated using non-parametric Spearman's Rank analysis. The results showed that 6 species of birds were found, among them are Eurasian tree sparrow (Passer montanus), Cave swiflet (Collocalia linchi), Sooty-headed bulbul (Pycnonotus aurigaster), Nectarinidae, Spotted Dove (Streptopelia chinensis), and Olive-backed tailorbird (Orthotomus sepium) and 2 of them are insectivores, namely Cave swiflet (Collocalia linchi) and Olive-backed tailorbird (Orthotomus sepium). The herbivory level of control oil palm plants ranged from 0.005 to 0.303, and the herbivory level of the bird exposed oil palms ranged from 0.013 to 0.295. The U test results from the research showed that There is no difference between the herbivori rate in bird exclosure and control, and the Spearman correlation test results showed that there was no correlation between the level of herbivory and the number of individuals for all bird species."

"The Encyclopedia of Control collects a broad range of short expository articles that describe the current state of the art in the central topics of control and systems engineering as well as in many of the related fields in which control is an enabling technology. The editors have assembled the most comprehensive reference possible, and this has been greatly facilitated by the publisher’s commitment continuously to publish updates to the articles as they become available in the future. Although control engineering is now a mature discipline, it remains an area in which there is a great deal of research activity, and as new developments in both theory and applications become available, they will be included in the online version of the encyclopedia. A carefully chosen team of leading authorities in the field has written the more than 200 articles that comprise the work. The topics range from basic principles of feedback in servomechanisms to advanced topics such as the control of Boolean networks and evolutionary game theory. Because the content has been selected to reflect both foundational importance as well as subjects that are of current interest to the research and practitioner communities, a broad readership that includes students, application engineers, and research scientists will find material that is of interest."

"This book introduces readers to the navigation, guidance and control technologies involved in single-spacecraft, double-spacecraft, and multiple-spacecraft tasks in elliptical orbits. It comprehensively covers the key technologies of guidance, navigation and control (GNC) system design for spacecraft in elliptical orbits, including the orbit design, formation configuration design and maintenance, autonomous navigation technology and relative navigation technology, as well as autonomous rendezvous technology. The methods that this book introduces are very close to actual practical engineering applications and presented in an accessible style.The book can serve as reference teaching material for senior undergraduates and postgraduates with space navigation related majors, while also providing essential information and guidance for research personnel and engineering technical personnel engaged in the development of GNC systems for spacecraft."