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All Journal Bulletin of Scientific Contribution : Geology Indonesian Journal of Applied Sciences IJOG : Indonesian Journal on Geoscience Forum Geografi Sinkron : Jurnal dan Penelitian Teknik Informatika JITK (Jurnal Ilmu Pengetahuan dan Komputer) Buletin Sumber Daya Geologi Jurnal Teknologi Energi JATI (Jurnal Mahasiswa Teknik Informatika) REMIK : Riset dan E-Jurnal Manajemen Informatika Komputer Jurnal Infortech Indonesian Journal on Geoscience Indonesian Journal on Geoscience Journal of Geosciences and Applied Geology Jurnal Vokasi Bisnis Digital, Akuntansi Lembaga Keuangan Syariah dan Usaha Perjalanan Wisata
Adjat Sudradjat
Universitas Padjadjaran
Civil Engineering, Building, Construction & Architecture Computer Science & IT Decision Sciences, Operations Research & Management Earth & Planetary Sciences Economics, Econometrics & Finance Education Energy Engineering Environmental Science Library & Information Science Other

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The Characteristics of Lahar in Merapi Volcano, Central Java as the Indicator of the Explosivity during Holocene Sudradjat, Adjat; Syafri, Ildrem; Paripurno, E. T.
Indonesian Journal on Geoscience Vol 6, No 2 (2011)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1903.942 KB) | DOI: 10.17014/ijog.v6i2.116

Abstract

DOI: 10.17014/ijog.v6i2.116Merapi Volcano in Central Java has been the most active volcano during Holocene time. As a strato volcano, Merapi exhibits alternating volcanic activities of effusive and explosive characters and self destruction. The explosivity index has evolved during the last ten thousand years. The effusive activities were characterized by the occurrence of lava flows, the development of lava dome, and the production of the “nuee ardente d’avalanche” called Merapi type. The explosive stage is frequently accompanied by the occurence of pyroclastic flows. The present investigation is attempted to reveal the relationship between the characteristics of lahar and the evolution of the activity of Merapi Volcano. The quantitative analysis was focused on the size and shape of the lahar components particularly that of pumice as the main indicators in 73 measured stratigraphic columns of lahar deposits. In addition, the main chemical element rim structures of hornblende identified in lahar components indicate the different lahar units. There are five lahar units and five groups of Merapi activities which can be distinguished. It can be concluded that the characteristics of lahar reflect the evolution of the activities in the past. The risk analyses of Merapi Volcano therefore can be enlarged to cover the possible hazard based on the lahar characteristics.
Caldera of Godean, Sleman, Yogyakarta: A Volcanic Geomorphology Review Hartono, Hill Gendoet; Sudradjat, Adjat; Verdiansyah, Okki
Forum Geografi Vol 31, No 1 (2017): July 2017
Publisher : Universitas Muhammadiyah Surakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23917/forgeo.v31i1.2821

Abstract

Godean hills is located approximately 10 km westward from the Yogyakarta City. The landscape of Godean hills and plains is affected by various factors, such as lithology, geological structure, and sub-aerial process. The purpose of this study was to reveal the landscape of Godean. The method consisted of field study, morphological variables assessment, rock sampling, and laboratory analysis. The results of field mapping indicated that the landscape of Godean  is an isolated hill with a steep slope of >40° and an elevation of +231 m a.s.l, passed by the rivers flows from northeast to southwest that disembogue into the west part of Kulon Progo. The morphologhy of Godean hills varies including G. (Gunung/Mountain) So (+173 m amsl), G. Gede (+218 m a.s.l), G. Wungkal (+187 m a.s.l), G. Butak (+154 m a.s.l), and G. Berjo ( + 175 m a.s.l), dominated by the lithology of igneous rock, which is composed of porphyry andesite-microdiorite, pumice lapilli, and quartz rich lapilli-tuff. In addition, most of the igneous rocks have weathered and have been altered to clays, while the deposition from Merapi volcano formed a landscape with an altitude between +100–+150 m a.s.l surrounding Godean hills. Sentolo Formation was found in Kembang, Bantul, which is located approximately ±5km in the south of the study area N93ºE/12º,  while the distribution in the southwest and northeast relatively covers the Godean hills in curve shape. The results of the analysis provide information related with Godean landscape that it is the remains of the volcanic caldera, with various igneous rock types and volcaniclastics deposits, as well as endured the occurrences of hydrothermal alteration and mineralization. Further geophysical research is required to determine the configuration of igneous rocks under the earths surface.
KRITERIA KERUSAKAN AKIBAT PELEDAKAN PADA PEMBUATAN TEROWONGAN CIURUG, TAMBANG EMAS PONGKOR, KABUPATEN BOGOR, PROVINSI JAWA BARAT Suwandhi, Awang; Rosana, Mega Fatimah; Sudradjat, Adjat; Wattimena, Ridho Kresna
Buletin Sumber Daya Geologi Vol 12, No 2 (2017): Buletin Sumber Daya Geologi
Publisher : Buletin Sumber Daya Geologi

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Abstract

Untuk mencapai urat (vein) bijih di lokasi Central pada Level 500 mdpl, Ciurug, dibuat terowongan baru yang dinamakan RU4C-L500 dengan menerapkan teknik peledakan. Terowongan tersebut dirancang berukuran lebar 4 m, tinggi 4 m dan panjang 100 m sampai ke cross-cut menuju urat bijih. Penelitian dilakukan dengan tujuan untuk mendapatkan kriteria kerusakan terowongan yang diakibatkan oleh induksi getaran peledakan yang berpotensi menghasilkan overbreak, sehingga ukuran terowongan menjadi lebih lebar dari rencana semula. Pendekatan Blast Damage Index (BDI) digunakan sebagai metode untuk memperoleh tingkat kerusakan terowongan tersebut. Terowongan menerobos batuan andesit vulkanik yang berdasarkan hasil pengujian memiliki kecepatan rambat gelombang seismik 4157 m/det, densitas 2,37 g/cc dan kuat tarik 8,10 MPa. Batuan tersebut tergolong batuan berkekuatan sedang hingga keras dengan nilai Rock Mass Rating (RMR) antara 58,3 sampai 69,5. Data getaran peledakan diukur dengan menggunakan geofon pada jarak yang aman dari titik ledakan dan menghasilkan Peak Vector Sum (PVS) berkisar antara 2 mm/s sampai 120 mm/s. Hasil pengolahan data getaran menunjukkan, bahwa nilai BDI sebesar 2 yang mengidentifikasi adanya ambrukan terowongan karena induksi getaran peledakan terjadi pada jarak kurang dari 3 m dari titik ledakan. Besar getaran peledakan yang mengambrukan batuan andesit vulkanik tersebut mencapai PVS 1170 mm/s. Pada jarak antara 3,0 m sampai 10 m tidak terjadi kerusakan terowongan yang parah dan dapat direhabilitasi. Kondisi tersebut diidentifikasi oleh nilai BDI 0,5 sampai 1. Kemudian pada jarak di atas 10 m induksi getaran peledakan tidak lagi berpengaruh terhadap kerusakan atau kestabilan dinding terowongan. 
KETERSEDIAAN SUMBER DAYA ENERGI UNTUK PENGEMBANGAN KELISTRIKAN DI SUMATERA SELATAN sudradjat, adjat
185P -3466
Publisher : Agency for the Assessment and Application of Technology

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (341.102 KB)

Abstract

Sumatera Selatan merupakan propinsi yang sangat padat akan sumber energi fosil yang terdiri dari minyak bumi, gas bumi dan batubara, disamping potensi sumber energi hidro yang mampu untuk pembangkitan listrik sampai 405 MW. Permintaaan akan energi listrik dari tahun ketahun terus meningkat dengan pertumbuhan sekitar 9 % setiap tahunnya. Oleh karena itu untuk memenuhi permintaan akan energi listrik maka diperlukan suatu perencanaan penyediaan pembangkit listrik yang memakai teknologi pembangkit listrik yang memanfaatkan sumber energi yang tersedia dan diprioritaskan memakai sumber energi fosil non-minyak. Pada tulisan ini akan dijelaskan jumlah potensi sumber energi fosil dan air di Sumatera Selatan, kebutuhan listrik serta strategi pemenuhan suplai listrik dengan pilihan teknologi pembangkit memakai sumber energi yang tersedia.
Tectonic Control on the Formation of Cleats in the Coal Beds of the Sajau Formation, Berau Basin, Northeast Kalimantan Sudradjat, Adjat; Hamdani, Ahmad Helman
Indonesian Journal on Geoscience Vol 5, No 3 (2018)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (4497.853 KB) | DOI: 10.17014/ijog.5.3.235-250

Abstract

DOI: 10.17014/ijog.5.3.235-250Coal seams of lignite- to subbituminous rank of Pliocene-age from the Sajau Formation of the Berau Basin are characterized by the presence of a natural fracture system, including cleats. Often, these opening-mode fractures consist of two orthogonal sets (face and butt cleats), both almost perpendicular to the bedding. This paper describes the distribution of orientation, spacing, and aperture of cleats formed in the seams of the Sajau Formation. All observations and measurements were conducted at macroscopic, mesoscopic, and microscopic scales. The butt cleat mean orientations are NE-SW and NW-SE, whereas the face cleat mean orientations are NNE-SSW and NE-SE, and the cleat dip is at a high angle of 75° to the north. The angles between the orientations of these cleat sets are nearly 90°; that is, they are orthogonal. The spacing of the macroface cleats is between 9.52 and 14.46 cm (averaging 11.61 cm), while the spacing of the butt cleats is between 2.3 and 11.3 cm (averaging 5.35 cm). The mean aperture is 0.54 mm. In contrast, the mean spacing of the mesoface cleats is 3.09 mm, and the aperture measurements of these cleats range from 0.0478 to 0.0741 mm (averaging 0.0549 mm). The results obtained from outcrops and X-ray CT (computed tomography) scan clearly indicate that the NNE-SSW face cleat orientations are strictly parallel to the elongation of the main tectonic structures in the studied area. Their origin may be explained by their relationship with local tectonic stress (the maximum principal stress, σ1, was horizontal). Partial least square analysis of data collected from cleats and faults in the area indicates that a power law distribution exists between the cleat characteristics (spacing, density, and aperture), and the distance of the faults (R2 = 0.56). Cleat formation in the Sajau Formation was mainly controlled by the mechanical response to tectonic stresses, which generated a unique cleat network in the coal. Based on the SEM photography, it is concluded that the development of microcleats in the Sajau Formation resulted from both endogenic processes and tectonic activities as indicated by the change in the shape of the cleats, from straight line to curved shape and branching (intersection of multiple cleats that form a conical network at the end).
Sedimentation Process of Rambatan Formation in Larangan Brebes, North Serayu Range, Central Java Astuti, Bernadeta Subandini; Isnaniawardhani, Vijaya; Abdurrokhim, Abdurrokhim; Sudradjat, Adjat
Indonesian Journal on Geoscience Vol 6, No 2 (2019)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2520.882 KB) | DOI: 10.17014/ijog.6.2.141-151

Abstract

DOI:10.17014/ijog.6.2.141-151Rambatan Formation in the western part of North Serayu Basin, Brebes, Central Java, comprises generally flysch facies of turbidite sediments deposited in a deep marine environment. This formation is equivalent to Merawu Formation found in the eastern part of the basin and deposited in the environment of tidal flat to subtidal. The turbidite sediments were highly controlled by a rapid downward movement taking place continuously during Early to Late Miocene. The variation of the depositional environment has been the object of this research which aims to understand the sedimentation process of Rambatan Formation in this type locality with a modern turbidite approach. Rambatan Formation was deposited in N13-N19, as a deep marine sediment channel, turbidite, and deep marine tidal zone. The sedimentation was affected by gravity flow and contourite. The sediments on N13-N14 were marked by turbidite sediments until Middle N17. The sediment supply increased on Middle N17, as a sediment filler on a channel marked by contourite mud layer (muddy slump) and debris flow, with sources from the north. The increase of sediment supply was followed by an environmental transformation from a deep marine channel into deep marine tidal area. In N19, the sediments were redeposited as turbidite sediment, starting with debris flow in Middle N18.
MVC Concept in the Development of Information System for Rental Office Utilities Cost Sudradjat, Adjat; Atmaja, Rahdian Kusuma; Ramadan, Rino; Ispandi, Ispandi
REMIK: Riset dan E-Jurnal Manajemen Informatika Komputer Vol. 4 No. 1 (2019): Remik Volume 4 Nomor 1 Oktober 2019
Publisher : Politeknik Ganesha Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (899.381 KB) | DOI: 10.33395/remik.v4i1.10237

Abstract

The calculation of the utilities cost of rental office in an office building that is still processed manually and conventionally is certainly troublesome for the building manager. Data processing by using office applications such as spreadsheets becomes ineffective when the number of tenants is increasing and transaction data coming in continues to grow. It causes stakeholders to often experience delays in obtaining the required reports. The research aims to build an application which can be used easily and able to provide information quickly and accurately in the process of calculating the utilities cost of rental office, which consists of the usage costs of electricity, water and gas. The application is developed by using MySQL database and PHP, HTML, CSS, Jquery as programming languages. It also applies the concept of MVC (Model-View-Controller) to the CodeIgniter framework and using agile method in developing the system. The research resulted in a web-based application of the utilities cost information system that is useful for building managers in the process of recording and calculating utilities cost automatically, so it can produce reports quickly and accurately. The advantage of the web-based application is that it allows stakeholders to obtain the required reports because they can be accessed directly online, so that the use of electricity, water and gas at rental offices can be well controlled.
Perancangan Sistem Pendukung Keputusan Seleksi Jabatan Pada PT. INI Jakarta Yunandar, Rahmat Tri; Sudradjat, Adjat
Sinkron : jurnal dan penelitian teknik informatika Vol. 2 No. 2 (2018): SinkrOn Volume 2 Nomor 2 April 2018
Publisher : Politeknik Ganesha Medan

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Abstract

Subyektifitas dalam pengambilan keputusan pada karyawan untuk ditempatkan atau mendapatkan promosi jabatan tertentu masih menjadi permasalahan dalam proses penilaian karyawan, terlebih jika beberapa karyawan yang diseleksi memiliki kemampuan satu sama lain yang tidak jauh berbeda. Dengan adanya penerapan sistem pendukung keputusan diharapkan akan mengurangi tingkat subyektifitas tersebut. Sebagai alternatif dalam pengambilan keputusan akan dilakukan perhitungan secara komprehensif terhadap seluruh kriteria yang melekat pada diri karyawan, sehingga diharapkan karyawan dengan kemampuan terbaiklah yang akan terpilih. Sistem pendukung keputusan dengan menerapkan analisa gap ditentukan berdasarkan pada data dan norma-norma sumber daya manusia itu sendiri. Dalam proses perhitungan gap tersebut terdapat 3 aspek pendekatan yaitu kapasitas intelektual, sikap kerja dan perilaku sebagai acuan untuk menentukan hasil rekomendasi karyawan yang akan dipilih. Hasil keseluruhan proses penilaian berupa skor ranking karyawan. Skor ranking ini yang menjadi dasar bagi manajemen atau pengambil keputusan untuk menseleksi karyawan yang paling tepat yang akan menempati jabatan tertentu pada instansi atau lembaga tersebut.
Sistem informasi Penjualan baju Batik Berbasis Web pada Toko 10S Pasar Grosir Setono Pekalongan Qomaruddin, Muhammad; Sudradjat, Adjat; Sopandi, Robi
Sinkron : jurnal dan penelitian teknik informatika Vol. 2 No. 2 (2018): SinkrOn Volume 2 Nomor 2 April 2018
Publisher : Politeknik Ganesha Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (571.956 KB)

Abstract

Toko Batik 10s adalah bidang usaha yang bergerak pada penjualan perlengkapan baju batik, dimana ada banyak toko yang juga menjual perlengkapan baju batik oleh karena itu Toko Batik 10s harus mampu untuk membuat peluang bisnisnya tetap ada dan selalu menjadi yang terdepan. Sistem Penjualan online ini meliputi pemakaian situs oleh pelanggan seperti registrasi pelanggan, pembelian dan pemesanan barang, pemberitahuan informasi terbaru. Pengaturan situs oleh admin baik poses pengamanan berbagai data, pengiriman barang, penambahan barang dan transaksi jual beli. Semua hal tersebut digunakan untuk menampung data-data untuk mempermudah proses sistem informasi.
KETERSEDIAAN SUMBER DAYA ENERGI UNTUK PENGEMBANGAN KELISTRIKAN DI SUMATERA SELATAN sudradjat, adjat
185P -3466
Publisher : Agency for the Assessment and Application of Technology

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (341.102 KB)

Abstract

Sumatera Selatan merupakan propinsi yang sangat padat akan sumber energi fosil yang terdiri dari minyak bumi, gas bumi dan batubara, disamping potensi sumber energi hidro yang mampu untuk pembangkitan listrik sampai 405 MW. Permintaaan akan energi listrik dari tahun ketahun terus meningkat dengan pertumbuhan sekitar 9 % setiap tahunnya. Oleh karena itu untuk memenuhi permintaan akan energi listrik maka diperlukan suatu perencanaan penyediaan pembangkit listrik yang memakai teknologi pembangkit listrik yang memanfaatkan sumber energi yang tersedia dan diprioritaskan memakai sumber energi fosil non-minyak. Pada tulisan ini akan dijelaskan jumlah potensi sumber energi fosil dan air di Sumatera Selatan, kebutuhan listrik serta strategi pemenuhan suplai listrik dengan pilihan teknologi pembangkit memakai sumber energi yang tersedia.
Co-Authors Abdurrokhim ⠀ Adhitiawarman, Adhitiawarman Adi Supriyatna Aditia, Nita Ahmad Helman Hamdani, Ahmad Helman Awang Suwandhi Baginda Oloan Lubis Banu Dwi Hanggoro, Dimas Bernadeta Subandini Astuti Dewi Laraswati Dicky Muslim Djajang Sukarna Dony Oscar dwi hartanto E. T. Paripurno Emi Sukiyah Febri Hirnawan Febrianti, Clara Ghofar Taufiq HARIYANTO HARIYANTO Hartono, Hill G. Hendri Hendri Henny Destiana Hill Gendoet Hartono Ildrem Syafri Irmawati Carolina Ishak Komarudin Ispandi Ispandi, Ispandi kurnio, Hananto Mega Fatimah Rosana Mega Fatimah Rosana Mochammad Imron Awalludin Muhamadsyah, Faisal Muhammad Qomaruddin Okki Verdiansyah Rachman Komarudin Rahdian Kusuma Atmaja Rahmat Tri Yunandar Retno Sari Ridho Kresna Wattimena Rino Ramadan Riyandi, Albert robi sopandi Rokhayati, Erna Rosana, Mega Fatimah Setianingsih Setianingsih, Setianingsih Setyo, Joko Sulis Suwandhi, Awang Syaiful Bachri Tutut Sunarminto Vijaya Isnaniawardhani Wina Widiati Yudhicara, Yudhicara