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Abstrak :
The fixed jacket is still the most common offshore structure used for drilling and oil production. The structure consists of tubular members interconnected to form a three-dimensional space frame, which can be categorized into a column structure. The structure usually has four to eight legs that are battered to achieve stability against axial compressive loads and toppling due to wave loads. The configuration of a typical member on the jacket structure has significant influence on buckling and fatigue strength. Horizontal and diagonal braces play an important role in resisting the axial compression and wave load on the global structure. This paper discusses the effect of symmetrical and asymmetrical configuration shapes in buckling and fatigue strength analysis on two types of fixed jacket offshore platforms. The axial compressive and lateral (wave) loads were considered and applied to both structures. The material and dimensions of the two structures were assumed to be constant and homogenous. Crack extension and corrosion were not considered. To assess the buckling and fatigue strength of these structures, due to the symmetrical and asymmetrical configuration shape, the finite element method (FEM) was adopted. Buckling analysis was performed on these structures by taking two-dimensional planes into consideration to obtain the critical buckling load for the local plane; fatigue life analysis was then calculated to produce the fatigue life of those structures. The result obtained by FEM was compared with the analytical solution for the critical buckling load. The stress-strain curve was also applied to show the difference between symmetrical and asymmetrical shapes. For fatigue life analysis, the procedure of the response amplitude operator was applied.

Abstrak :
This article introduces two interconnected approaches to provenance research on anthropological facial plaster-casts taken from living individuals. It focuses on three series of facial casts taken by Dutch anthropologist Johannes Pieter Kleiweg de Zwaan (1875-1971) in the Netherlands East Indies in 1907 and 1910. It suggests that “reading” the facial casts as an archive of faces and an archive of plaster has the potential to reveal information systematically left out in their object biographies. Through this reading process, the colonial networks of control and power asymmetries which made the plaster-casting possible are examined. It seeks out additional information to bring the object closer to the person whose face was appropriated for various colonial ends. This epistemological experiment explores the first steps which can be taken to create a decolonial view of the large anthropological plaster-cast collections in European museums which have been left anonymous for decades.

Abstrak :
Salah satu contoh penerapan energi baru terbarukan EBT yang sedang berkembang adalah Pembangkit Listrik Tenaga Surya PLTS. Berdasarkan data Rencana Usaha Penyediaan Tenaga Listrik (RUPTL) PT PLN (Persero) 2019-2028 disebutkan bahwa potensi energi matahari (surya) di Indonesia sebesar 207.898 MW (4,80 kWh/m2/hari) dan hanya sebesar 78,5 MW kapasitas terpasang di Indonesia. Pada penelitian ini dilakukan studi interkoneksi PLTS 5 MWp dengan jaringan tegangan menengah 20 kV Daerah X sebagai salah satu penerapan energi baru terbarukan di Indonesia. Studi interkoneksi mencakup analisis aliran daya dan analisis gangguan hubung singkat tiga fasa. Pada analisis aliran daya diperoleh hasil bahwa sistem PLTS mampu menyuplai kebutuhan beban pada sistem sebesar 5.000 kW daya aktif. Didapatkan juga bahwa interkoneksi PLTS dengan sistem mengakibatkan kenaikan level tegangan dari setiap bus pada sistem sebesar 0,08-1,41%, serta membuat perubahan persentase pembebanan komponen sebesar 0,01% hingga 93,01%. Hasil analisis gangguan hubung singkat tiga fasa menunjukkan bahwa interkoneksi PLTS dengan sistem memiliki besar nilai arus gangguan hubung singkat sebesar 5,70-7,01 kA, sehingga nilai arus gangguan untuk seluruh bus masih jauh di bawah nilai kapasitas pemutusan arus hubung singkat sistem proteksi yang bernilai 25 kA. Hasil studi interkoneksi yang diperoleh menujukkan bahwa interkoneksi sistem PLTS 5 MWp dengan jaringan tegangan menengah 20 kV Daerah X dapat dilakukan.

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One example of the application of new renewable energy that is currently developing is solar power plant. Based on data from Rencana Usaha Penyediaan Tenaga Listrik (RUPTL) PT PLN (Persero) 2019-2028, it is stated that the potential of solar energy in Indonesia is 207,898 MW (4.80 kWh/m2/ day) and only 78.5 MW of capacity installed in Indonesia. In this study, a 5 MWp solar power plant was interconnected with a 20 kV medium-voltage network of Area X as one of the renewable energy applications in Indonesia. Interconnection studies include power flow analysis and three phase short circuit fault analysis. In the analysis of the power flow results obtained that the Solar Power Plant system is capable of supplying the load requirements to the system of 5,000 kW active power. It was also found that interconnection of solar power plant with the system resulted in an increase in the voltage level of each bus in the system by 0.08 to 1.41%, as well as changing the percentage of component loading by 0.01% -93.01%. The results of the three-phase short circuit fault analysis show that the interconnection of the solar power plant system has a short circuit fault current value of 5.70-7.01 kA, so the fault current value for the whole bus is still far below the value of the short circuit current capacity of the protection systems short circuit worth 25 kA. The results of the interconnection study showed that interconnection of a 5 MWp solar power plant system with a 20 kV medium voltage network Area X can be carried out.

Abstrak :
Energi listrik merupakan sumber energi yang penting bagi kehidupan manusia. Hampir semua sektor kehidupan membutuhkan energi listrik. Saat ini permintaan tenaga listrik terus meningkat disaat yang sama juga masalah baru muncul, yaitu perluasan pembangkit tenaga listrik dan pembangunan saluran transmisi yang sangat terbatas. Oleh karena itu, terjadi pola pembebanan yang dipaksakan pada pembangkit tenaga listrik dan transmisi yang terlampau berat. Pada sistem tegangan yang jauh dari pembangkit cenderung akan mengalami jatuh tegangan yang paling besar. Pada skripsi ini lokasi studi kasusnya di daerah Serpong - Lengkong dikarenakan jarak Transmisi 150 kV ke beban dari pembangkit yang cukup jauh sehingga mengakibatkan jatuh tegangan yang cukup besar. Oleh karenanya, untuk mengatasi jatuh tegangan pada sistem transmisi, dipasang teknologi Flexible AC Transmission System berupa Static Synchronous Compenstor (STATCOM). Ketika dipasang STATCOM di serpong dan lengkong (kapasitas masing-masing peralatan 50 MVA) dengan nilai injeksi sebesar 5 Mvar. Tegangan sistem dari yang sebelumnya 133.18 kV dan 133.98 kV naik menjadi 142.25 kV dan 142.59 kV.

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Electric power is an important energy source for human life. Almost all sectors of life need electrical energy. The current demand for electricity continues to increase while the same issue recently emerged, namely the expansion of power plants and transmission line construction are very limited. Therefore, there is a pattern of loading imposed on power plants and transmission of outrageously heavy. On the system voltage away from the plant are likely to be experiencing the greatest voltage falls. In this thesis the location study his case in the area of Serpong-Lengkong due to the distance to the 150 kV Transmission load from plants far enough so that the resulting fall in voltage. Therefore, to cope with the falling voltage on the transmission system, installed the technology of Flexible AC Transmission System in the form of Static Synchronous Compenstor (STATCOM). When installed in serpong STATCOM and lengkong (capacity of each piece of equipment 50 MVA) with a value of 5 Mvar injection. Voltage system from the previous 133.18 kV and 133.98 kV up to 142.25 kV and 142.59 kV.