Articles

FLUKTUASI BEDA TEKANAN DARI POLA ALIRAN SLUG AIR-UDARA PADA ALIRAN DUA FASE SEARAH PIPA HORIZONTAL Santoso, Budi; Indarto, Indarto; Deendarlianto, Deendarlianto; W., Thomas S.
ROTASI "JURNAL TEKNIK MESIN" VOLUME 14, NOMOR 2, APRIL 2012
Publisher : ROTASI "JURNAL TEKNIK MESIN"

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Abstract

Karakteristik fluktuasi beda tekanan aliran slug dua fase udara-air diselidiki dalam pipa horisontal dengan panjang 10 m dan diameter dalam 24 mm. Tujuan penelitian ini adalah mengidentifikasi karakteristik dari fluktuasi beda tekanan pola aliran slug menggunakan analisis statistik, probability density function (pdf), autokorelasi dan power spectral density (psd). Sebuah sensor Differential Pressure Tansducer (DPT) dipasang untuk merekam fluktuasi beda tekanan aliran slug. Sinyal beda tekanan dikondisikan oleh pressure amplifier/signal conditioning dan diubah menjadi sinyal digital menggunakan peralatan Analog to Digital Converter (ADC). Karakteristik dari fluktuasi beda tekanan aliran slug sangat dipengaruhi oleh kecepatan superfisial fluida. Perubahan kecepatan superfisial udara dan kecepatan superfisial air dapat dibedakan dengan jelas menggunakan analisis statistik, PDF, autokorelasi dan PSD.
PEMISAHAN ALIRAN KEROSEN-AIR (Pada Variasi Sudut Kemiringan Side Arm vertikal keatas) Puspitasari, Dewi; Indarto, Indarto; Purnomo, Purnomo; Khasani, Khasani
ROTASI "JURNAL TEKNIK MESIN" VOLUME 14, NOMOR 2, APRIL 2012
Publisher : ROTASI "JURNAL TEKNIK MESIN"

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Abstract

Penelitian mengenai pemisahan fase air-kerosen yang melewati T-junction telah dilakukan. Hasil pemisahan fase akan diamati dengan mengubah sudut kemiringan side arm (branch) dimulai dari posisi vertical keatas 90o, ,60o dan 30o dengan radius belokan 15 mm.Untuk mengamati pengaruh sudut kemiringan side arm terhadap pemisahan fase yang dihasilkan maka dibuatlah seksi uji T-junction dengan diameter pipa horisontal 36 mm, diameter side arm 26 mm (rasio diameter 0,7), bahan pipa adalah acrylic dengan variasi water cut 49% - 70%, kecepatan superfisial air 0,20 ~ 0,39 m/s, kecepatan superfisial kerosene 0,15 ~ 0,25 m/s pada tiga variasi hambatan downstream. Berdasarkan data hasil eksperimen dan visualisasi aliran pada seksi uji, hasil pemisahan fase terbaik dicapai pada sudut kemiringan branch 90o dengan tekanan downstream 107843,5 Pa, watercut 49% yang menghasilkan fraksi kerosene di branch Fk = 94,7% dan fraksi air di branch Fw = 3,4% dengan efisiensi pemisahan fase sebesar η = 95%. Kondisi terbaik diatas diperoleh pada Jw = 0,20 m/s, Jk = 0,22 m/s pada pola aliran Three Layer (3L-2).
KARAKTERISTIK DAN PENDEKATAN KINETIKA GLOBAL PADA PIROLISIS LAMBAT SAMPAH KOTA TERSELEKSI Himawanto, Dwi Aries; Indarto, Indarto; Saptoadi, Harwin; Rohmat, Tri Agung
REAKTOR Volume 13, Nomor 3, Juni 2011
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (54.241 KB) | DOI: 10.14710/reaktor.13.3.140-147

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CHARACTERISTICS AND GLOBAL KINETIC APPROACH ON THE SLOW PYROLYSIS OF SELECTED MUNICIPAL WASTE. Municipal Solid Wastes (MSW) has a great potential as a clean renewable feedstock for producing modern energy carriers through thermochemical conversion processes called pyrolysis. However, despite their enormous potential as energy sources, their thermal characteristics are still not well known. In the present study, the pyrolysis characteristics and pyrolysis kinetics of MSW single components (i.e bamboo wastes, banana leaves wastes, wrapping wastes, and styrofoam wastes) and their mixture were investigated. The 20 grams sample were heated in a furnace under nitrogen environment from ambient temperature to 400°C at a heating rate of 10°C/min and held for 30 min. The results of the research showed that bamboo wastes and banana leaves wastes could be catogorized as low stability organics, while wrapping wastes could be catagorized as polymer mixture materials, while styrofoam wastes could be catagorized as plastic materials. The research also revealed that the global kinetic method  could be used to predict the MSW single component activation energy. Sampah kota mempunyai potensi untuk dikembangkan menjadi sumber energi alternatif terbarukan melalui proses pirolisis. Namun demikian, pemahaman mengenai karakteristik termal proses pirolisis dari sampah kota masih belum banyak diketahui. Dalam penelitian ini, dilakukan analisa thermogravimetry dari komponen-komponen tunggal sampah kota yang meliputi sampah bambu, sampah daun, sampah bahan pengemas, dan sampah styrofoam maupun campuran antara komponen-komponen tersebut. Penelitian ini dilakukan untuk mendapatkan karakteristik pirolisis komponen-komponen yang diteliti, meliputi profil proses devolatilisasi dan energi kinetik. Penelitian dilakukan dengan menempatkan sampel seberat 20 gram dalam sebuah tungku dan menaikkan temperatur tungku dengan laju pemanasan 10°C/min. Temperatur akhir sampel dipertahankan pada 400°C  selama 30 menit. Untuk menjamin terjadinya proses pirolisis, maka dialirkan nitrogen dengan laju 100 ml/menit ke dalam reaktor. Hasil penelitian menunjukkan bahwa sampah bambu dan sampah daun pisang dapat dikategorikan kedalam bahan organik dengan kestabila rendah. Sampah bahan pengemas cenderung masuk dalam katagori bahan campuran polimer, sedangkan sampah styrofoam dapat dikategorikan ke dalam material plastik. Hasil penelitian juga menunjukkan bahwa metode kinetika global dapat digunakan untuk memprediksi nilai energi aktivasi dari komponen tunggal sampah kota.
Uji keandlan model sacramento pada DAS Bedadung dan DAS Kloposawit Wahyuningsih, Sri; Novita, Elida; Indarto, Indarto
Jurnal AGROTEKNOLOGI Vol 4, No 1 (2010)
Publisher : Jurnal AGROTEKNOLOGI

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Sacramento model is once of rainfall runoff library (RRL) model which used to measure the flo component that include rainfall, evaporation and discharge.
IDENTIFIKASI DAN KLASIFIKASI PERUNTUKAN LAHAN MENGGUNAKAN CITRA ASTER (Landuse Identification and Classification Using ASTER Multispectral Data) Indarto, Indarto; Faisol, Arif
Media Teknik Sipil Vol 9, No 1 (2009): JANUARI 2009
Publisher : Media Teknik Sipil

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ASTER (Advanced Space borne Thermal Emission and Reflection Radiometer) is classified as new sensor based on the TERRA satellite developed in the recent years. ASTER has been developed to provide image for monitoring environmental phenomenon. ASTER data offer more option for spatial resolution (60m, 30m and 15m) and more spectral resolution that suppose sufficient to capture main nomenclature of land use than usual imagery (e.g.: Landsat TM). This article shows the process of image treatment, classification, and interpretation of ASTER data to classify land use at Sampean Watershed. Two method of classification (supervised and unsupervised) are then compared to obtain the best classification. Methodology comprise of: pre-processing, survey, classification and interpretation. Classification is conducted using un-supervised and supervised methods. The classification results of these two methods are then compared to digital map (peta RBI). Supervised classification identified 7 main features of land use, while un-supervised classification only identified 3 main class of land use. The works show that supervised classification enhances the number of land use features identified and classified.
Experimental Study on the Effect of Initial Temperature on CHF in a Vertical Annulus Narrow Channel with Bilateral Heated Juarsa, M.; Koestoer, RA.; Putra, N.; Indarto, Indarto; Habsari, S.
Atom Indonesia Vol 37, No 2 (2011): August 2011
Publisher : PPIKSN-BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (311.213 KB) | DOI: 10.17146/aij.2011.61

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Study on understanding of the complexities of boiling in the narrow channel which was occured in a severe accident on nuclear power plant has been carried out in experimentally using simulation apparatus in order to achieve the safety management capability. Critical Heat Flux (CHF) is one important parameter to control heat during transient accident. The methodology of research is an experiment using experiment apparatus called HeaTiNG-01 test section with modifications in the outside pipe using stainless steel material as the reactor vessel wall simulation. Experiments were conducted by heating the heated rod as a simulation of debris until the desired initial temperature by bilateral heated. Then water with a saturation temperature in atmospheric was poured gravitationally into the narrow channel. Data acquisition system recorded temperature changes in transient during the cooling process. The transient temperature profile in double heating surface and rewetting point (rewet fronts) was characterized. Experiment was conducted at three initial temperature variations i.e. 650oC, 750oC and 850oC and using channel width 1 mm. Experiment data was used to calculate heat flux then to fitting CHF form boiling curve. The results showed that CHF in outer pipe is higher than heated rod, these conditions explain that more heat is released through the outer pipe, so that the heat control can be done from outside the system to reduce the temperature quickly. The average value of CHF for each vertical position 100 mm and 400 mm at outer pipe are 380 kW/m2 and 733 kW/m2, and then at the heated rod are 250 kW/m2 and 497 kW/m2. Received: 20 November 2010; Revised: 25 July 2011; Accepted: 08 August 2011
The Visualization Study on the Slug Flow Mechanisms of the Air-Water Two-Phase in a 50 mm Horizontal Pipe Dinaryanto, Okto; Hudaya, Akhmad Zidni; Deendarlianto, Deendarlianto; Indarto, Indarto
SENATIK STT Adisutjipto Vol 4 (2018): Transformasi Teknologi untuk Mendukung Ketahanan Nasional [ ISBN 978-602-52742-0-6 ]
Publisher : Sekolah Tinggi Teknologi Adisutjipto

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (560.273 KB) | DOI: 10.28989/senatik.v4i0.171

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The slug flow phenomena are often encountered in various industrial applications such as petroleum, process, and power plant. The presence of slug flow should be avoided as it causes structural damage due to resonance, corrosion and pipes blast. From the view point of multiphase flow, the understanding of the slug initiation mechanism is very important in pipeline design. This research is conducted using horizontal transparent acrylic pipes with diameters of 50 mm with a variation on the superficial velocity of water between 0,1 m/s and 0,77 m/s and superficial velocity of air between 0,31 m/s and 6,2 m/s. In the present experimental study, the slug initiation mechanisms was explained by visual observation by using high speed video cameras. As the results, the slug flow initiation mechanism were clarified. Furthermore, the proposed of flow initiation map was introduced.
Impact of Stakeholder Psychological Empowerment on Project Success Chandra, Herry Pintardi; Indarto, Indarto; Wiguna, I Putu Artama; Kaming, Peter F
IPTEK The Journal for Technology and Science Vol 22, No 2 (2011)
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v22i2.63

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The relationship between psychological empowerment of stakeholders and project success is an important thing that must be known by project manager. This research developed and tested the model to predict how well the impact of stakeholder psychological empowerment on project success. Stakeholder psychological empowerment was defined to have five indicator variables covering intrinsic motivation, opportunity to perform, ability to perform, task behaviors, and contextual behaviors. Meanwhile, project success can be measured by cost performance, time performance, quality performance, profitability, and customer satisfaction. In this study, it was hypothesized that stakeholder psychological empowerment influenced project success. Based on the data obtained from a questionnaire survey carried out to 204 respondents, structural equation modeling (SEM) was used for predicting the performance of project success. It was found that stakeholder psychological empowerment influenced project success, especially on the ability to perform of stakeholders.
MENINGKATKAN KINERJA PEGAWAI NEGERI SIPIL (PNS) MELALUI PENGELOLAAN KECERDASAN DAN SIKAP ETIS Adhinurwanto, Dicky; Indarto, Indarto
Jurnal Riset Ekonomi dan Bisnis Vol 10, No 2 (2017): Agustus 2017
Publisher : Pascasarjana Universitas Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (451.016 KB) | DOI: 10.26623/jreb.v10i2.1135

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Faktual problem yang saat ini sedang dihadapi oleh PNS adalah sorotan negatif akibat kemerosotan mental dan moral yang ditunjukkan dalam melaksanakan tugas pelayanan, mengemukanya praktek KKN (Kolusi, Korupsi dan Nepotisme), menguaknya issue amoral yang telah melibatkan penyelenggara negara, juga terungkap perilaku kekerasan dalam rumah tangga yang dilakukan oleh anggota PNS adalah fakta yang tidak dapat dipungkiri. Mengacu pada temuan faktual problem yang ada maka masalah penelitian yang dirumuskan adalah “Bagaimana meningkatkan sikap etis dan kinerja PNS di lingkungan kantor Setda Provinsi Jawa Tengah?”.Dengan menggunakan data yang diperoleh melalui kuesioner yang disebarkan kepada responden pegawai Biro Umum di Kantor Setda Provinsi Jawa Tengah, penelitian ini menguji pengaruh kecerdasan emosional, kecerdasan intelektual, dan kecerdasan spiritual terhadap sikap etis dan kinerja. Pengujian pengaruh antar variabel dilakukan dengan menggunakan Uji Regresi Berganda.Hasil pengujian regresi berganda menunjukkan bahwa kecerdasan emosional, kecerdasan intelektual, dan kecerdasan spiritual terbukti berpengaruh positif signifikan terhadap sikap etis. Hasil penelitian ini juga menunjukkan bahwa kecerdasan emosional, kecerdasan intelektual, kecerdasan spiritual serta sikap etis terbukti memiliki pengaruh signifikan terhadap kinerja pegawai. Factual problems currently being faced by civil servants is negative spotlight due to mental deterioration and moral demonstrated in carrying out the ministry, collusion, corruption and nepotism, to reveal issue amoral that has involved state officials, also revealed violent behavior in the home the stairs were made by members of civil servants is a fact that can not be denied. Referring to the factual findings of the problems formulated the research problem is "How to improve ethical attitudes and performance of civil servants in the Central Java Provincial Secretariat office?".By using the data obtained through a questionnaire distributed to respondents employee in the Office of General Bureau Secretariat of Central Java province, this study examines the effect of emotional intelligence, intellectual, and spiritual intelligence of the ethical attitude and performance. Testing the influence between variables is done by using multiple regression test.The test results of multiple regression showed that emotional intelligence, intellectual, and spiritual intelligence proved significant positive effect on the ethical attitudes. The results also indicate that emotional intelligence, intellectual, spiritual intelligence and ethical attitude shown to have a significant influence on employee performance.
ANALISIS PENGARUH PROFITABILITAS LIKUIDITAS DAN PERTUMBUHAN PERUSAHAAN TERHADAP KEBIJAKAN UTANG SERTA DAMPAKNYA TERHADAP TARIF PAJAK EFEKTIF Sarwoasih, Sri; Indarto, Indarto
Jurnal Riset Ekonomi dan Bisnis Vol 11, No 1 (2018): April 2018
Publisher : Pascasarjana Universitas Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (740.819 KB) | DOI: 10.26623/jreb.v11i1.1075

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Penelitian ini bertujuan untuk mengetahui pengaruh profitabilitas yang diproksikan dengan return on asset, pengaruh likuiditas yang diproksikan dengan current ratio serta pengaruh pertumbuhan perusahaan yang diproksikan dengan asset growth dan sales growth terhadap effective tax rate dengan debt to equity ratio sebagai variable intervening dan untuk mengetahui pengaruh return on asset dan sales growth secara langsung terhadap effective tax rate. Jenis data yang digunakan berupa data kuantitatif dengan metode purposive sampling, sampel penelitian adalah perusahaan manufaktur yang terdaftar di Bursa Efek Indonesia tahun 2014–2016 sejumlah 108 sampel. Hasil uji hipotesis menyatakan return on asset dan current ratio berpengaruh signifikan terhadap debt to equity ratio, asset growth dan sales growth tidak berpengaruh signifikan terhadap debt to equity ratio, debt to equity ratio, return on asset,  dan  sales growth berpengaruh signifikan terhadap effective tax rate. Hasil sobel test model 1 : debt to equity ratio berhasil memediasi return on asset dan effective tax rate, Model 2 : debt to equity ratio tidak berhasil memediasi sales growth dan effective tax rate.This research aims to determine the effect of profitability proxies by return on assets, the influence of liquidity proxies by current ratio and the influence of the company’s growth proxies by asset growth and sales growth to the effective tax rate to the debt to equity ratio as intervening variable and to know the effect of return on asset and sales growth directly to effective tax rate. The types of data used in the form of quantitative data with using purposive sampling method, the sample research is a manufacturing company listed on the Indonesia Stock Exchange in 2014-2016 with number of samples are 108.             Hypothesis test result : return on asset and current ratio has significant effect to debt to equity ratio, asset growth and sales growth has not significant effect on debt to equity ratio, debt to equity ratio, return on asset and sales growth has a significant effect on effective tax rate. The results of the sobel test model 1: debt to equity ratio succeed in mediating return on assets and effective tax rate, Model 2: debt to equity ratio did not succeed in mediating sales growth and effective tax rate.
Co-Authors Adhinurwanto, Dicky Afisna, Lathifa Putri Agung Priyo Subakti Agus Kirwanto Ahmad Yusron, Ahmad Akhmad Zidni Hudaya Alva Edy Tontowi Anggita Gigih Wahyu Iriawan, Anggita Gigih Wahyu Aprih Santoso, Aprih Ardian Nur Fakrudin Arif Faisol Ash Shiddiq, Dimas Ghufron Ash-Shiddiq, Dimas Ghufron Askin, Askin Askin, Askin Askin, M. Aulia Novitasari Bambang Sri Anggoro Boedi Susanto Budi Santoso Catrawedarma, I Gusti Ngurah Bagus Deendarlianto Deendarlianto Dewi Puspitasari Djoko Santoso Dwi Aries Himawanto Elida Novita Ernanda, Heru Fauzi, Fiqy Hamid Ahmad Harwin Saptoadi Herry Pintardi Chandra Hidayah, Pradita Dewi Hidayat, M. Dian Nurul I Putu Artama Wiguna Idah Andriyani IGN. Bagus Catrawedarma Ika Kartika Kaliwantoro, Nur Khasani Khasani M. Juarsa Mahmuddin Mahmuddin Mandala, Marga Mardyasari, Lucia Hartiningtyas Marsetyawan HNE Soesatyo Mohammad Juffrie, Mohammad Muhardjo Pudjojono, Muhardjo Mulya Juarsa Mustakim Mustakim N. Putra Narulita, Windy Ninin Ismulayati, Ninin Nugroho, Fellando Martino Nurfalitasari, Iftika Okto Dinaryanto Peter F Kaming Prabowo, Oxy Mahendra Pradusuara, Franes Pudjojono, Muharyo Purnomo Purnomo R. DHIMAS DHEWANGGA P, R. DHIMAS RA. Koestoer Rini Dharmastiti Rohman, Isfi roni S. Habsari Sahat, Afro Aransa Samsul Kamal Sarwoasih, Sri Sri Wahyuningsih Sriatun Sriatun Suhardjo Widodo Sukamta Sukamta Sukmana, Damar Tedja Sumarno Sumarno Sumarsono, Agus Suprihatin Suprihatin Tasliman, Tasliman Thomas S. W. Tino Bachtiar, Tino Tri Agung Rohmat Tri Agung Rokhmat, Tri Agung Tris Lailatul Hasanah, Tris Lailatul Triyono, David Wibawa Endra Juwana, Wibawa Endra Widowati, Sri Yuni Wiratni Wiratni, Wiratni Yusuf Kurniawan