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All Journal Jurnal Teknologi Dan Industri Pangan Jurnal Rekayasa Proses Reaktor Prosiding Seminar Nasional Sains Dan Teknologi Fakultas Teknik JURNAL INTEGRASI PROSES Majalah Kulit, Karet, dan Plastik Jurnal Rekayasa Proses JURNAL ILMIAH AGRINECA Jurnal Rekayasa elektrika International Journal of Law, Crime and Justice
Rochmadi Rochmadi
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Aerospace Engineering Agriculture, Biological Sciences & Forestry Chemical Engineering, Chemistry & Bioengineering Computer Science & IT Control & Systems Engineering Education Electrical & Electronics Engineering Energy Engineering Industrial & Manufacturing Engineering Law, Crime, Criminology & Criminal Justice Materials Science & Nanotechnology Social Sciences Other

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OPTIMASI TEKNIK PEMBUATAN TABLET EFFERVESCENT SARI BUAH DENGAN RESPONSE SURFACE METHOD [Optimization of Processing Technique of the Fruit Juice Effervescent Tablet with Response Surface Method] Ansar Ansar; Budi Rahardjo; Zuheid Noor; Rochmadi Rochmadi
Jurnal Teknologi dan Industri Pangan Vol. 20 No. 1 (2009): Jurnal Teknologi dan Industri Pangan
Publisher : Departemen Ilmu dan Teknologi Pangan, IPB Indonesia bekerjasama dengan PATPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (807.186 KB)

Abstract

This research was aimed to study optimization of processing technique of fruit juice effervescent tablet with Response Surface Method (RSM). The research design used was central composite designs with three dependent variables including X1 (compression force), X2 (the citric acid concentration), and X3 (the sodium bicarbonate concentration), where independent variables was hardness and solubility of the tablet. The results of the research showed that the optimum tablets hardness was 40.53 N that reached at treatment compression force of 2339.8 N; the citric acid concentration of 352.82 mg/gr; and the sodium bicarbonate concentration of 561.62 mg/gr. Whereas the solubilitation of 41.99 second was resulted at treatment compression force of 1417.6 N; 334.24 mg/unit weight citric acid; and 593.90 mg/gr sodium bicarbonate. To get tablet characteristic with high hardness but solubilize quickly, was made at 1500 N compression force; the citric acid concentration 350  mg/gr; and the sodium bicarbonate concentration 500 mg/gr.
Biokomposit dari serat rami dan sekresi kutu lak termodifikasi dengan lateks terhidrasi dan tidak terhidrasi Eli Rohaeti; Mujiyono Mujiyono; Rochmadi Rochmadi
Majalah Kulit, Karet, dan Plastik Vol 31, No 1 (2015): Majalah Kulit, Karet, dan Plastik
Publisher : Center for Leather, Rubber, and Plastic Ministry of Industry, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20543/mkkp.v31i1.222

Abstract

Biocomposites are composite materials comprising one or more phases derived from a biological origin. Biocomposite with natural matrix developed more rapidly because they are more environmentally safer. The objective of research was to modify natural matrix from lac insect secretion with adding hydrated latex, to study effect of adding hydrated latex to the functional groups and the intrinsic viscosity of lac insect secretion, and to measure mechanical properties of biocomposite from modified lac insect secretion and ramie fiber. A sulfuric acid solution was used as catalyst in hydration of latex and then natural matrix of lac insect secretion was modified by adding hydrated latex. Biocomposite was prepared by mixing rami fiber and modified  lac insect secretion. It was then pressed with hydraulic press at 150 kgf/cm2 and 150oC for 15 minutes. Biocomposites were characterized using tensile tester according to ASTDM D 638-90 Type IV. The adding of catalyst caused the decreasing of intrinsic viscosity of latex. The adding of hydrated latex to natural matrix caused the increasing of intrinsic viscosity and functional group of matrix. The using 30% of catalyst and adding 10% of hydrated latex produced biocomposite with strength at break of 0.982 MPa, elongation at break of 1.189%, and Young modulus of 0.929 MPa.Keywords: biocomposite, hydration, latex, lac insect secretion, ramie fiber. ABSTRAK Biokomposit merupakan material komposit yang tersusun dari satu atau lebih komponennya berasal dari bahan alam. Biokomposit dari matriks alam berkembang lebih pesat karena lebih aman bagi lingkungan. Tujuan penelitian ini adalah untuk memodifikasi matriks dari sekresi kutu lak dengan penambahan lateks hasil hidrasi, mempelajari pengaruh penambahan lateks hasil hidrasi terhadap gugus fungsi dan viskositas intrinsik matriks, dan untuk mengukur sifat mekanik biokomposit dari matriks hasil modifikasi dengan serat rami. Lateks dihidrasi dengan variasi katalis asam sulfat 10, 20, dan 30% (m/m). Matriks alam dari sekresi kutu lak dimodifikasi dengan penambahan lateks hasil hidrasi sebanyak 5, 10, dan 15% (m/m). Biokomposit dibuat melalui pencampuran sekresi kutu lak hasil modifikasi dengan serat rami dan dipress pada tekanan 150 kgf/cm2 dan suhu 150oC selama 15 menit. Biokomposit dikarakterisasi menggunakan tensile tester sesuai dengan ASTDM D 638-90 tipe IV. Penambahan katalis menurunkan viskositas intrinsik lateks terhidrasi. Penambahan lateks terhidrasi meningkatkan viskositas intrinsik dan gugus fungsi matriks. Biokomposit dari matriks alam sekresi kutu lak termodifikasi lateks terhidrasi dengan penggunaan katalis 30% dan penambahan lateks terhidrasi sebesar 10% mempunyai kuat tarik sebesar 0,982 MPa, elongasi saat putus sebesar 1,189%, dan modulus Young sebesar 0,929 MPa.Kata kunci: biokomposit, hidrasi, lateks, sekresi kutu lak, serat rami.
Kinetika Reaksi Alkyd Resin Termodifikasi Minyak Jagung dengan Asam Phtalat Anhidrat Heri Heriyanto; Rochmadi Rochmadi; Arief Budiman
Jurnal Rekayasa Proses Vol 5, No 1 (2011)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (557.803 KB) | DOI: 10.22146/jrekpros.1892

Abstract

Reaksi esterifikasi anhidrida phtalat dengan monogliserida merupakan reaksi kondensasi membentuk polimer dengan rantai linier. Penelitian ini bertujuan untuk mempelajari kinetika reaksi alkid resin termodifikasi minyak jagung tanpa menggunakan katalis. Proses penelitian ada dua tahap yaitu tahap pertama reaksi alkoholisis dan tahap kedua reaksi esterifikasi. Tahap alkoholisis diawali dengan mereaksikan minyak jagung dan gliserol dengan perbandingan molar 1:2 pada suhu 250°C. Sampel diambil pada selang waktu 30 menit selama 3 jam untuk dianalisis kadar gliserol bebasnya dengan metode iodometri (FBI-AO2-03). Tahap esterifikasi adalah mencampurkan anhidrida phtalat ke dalam reaktor batch dengan perbandingan molar gliserol : anhidrida phtalat 3:2. Sampel dianalisis kadar gugus OH- dengan metode asetat anhidrida. Peubah-ubah yang dipelajari meliputi variasi suhu dari 230°C – 260°C dan variasi perbandingan ekivalen OH/COOH dari 1 – 1,25. Berdasarkan hasil penelitian diambil kesimpulan bahwa minyak jagung dan gliserol dapat dialkoholisis tanpa menggunakan katalis pada kisaran suhu 230°C – 260°C. Pengaruh suhu terhadap konstanta kecepatan reaksi dinyatakan dengan persamaan Arrhenius adalah sebagai berikut : k1=1,4647×104 exp (-8237,7/T) (g/mgek.men) k4=2,1398×109 exp (-14142/T) (g/mgek.men) Kata kunci: alkoholisis, esterifikasi, minyak jagung, gliserol, anhidrida phtalat Esterification of phthalic anhydrate with monoglyceride is a condensation reaction to form a linear chain polymer. The present work aimed at investigating reaction kinetics of alkyd resin modified with corn oil in the absence of catalyst. The work consisted of two steps i.e. alcoholysis and esterification. In the alcoholysis step, corn oil and glycerol were brought into reaction with a molar ratio of 1:2 at 250°C. Every 30 minutes during 3 hour reaction, reaction products were sampled to analyse the remaining free glycerol by iodometry method (FBI-AO2-03). In the esterification step, phthalic anhydrate was put in the batch reactor with a glycerol-phthalic anhydrate molar of 3:2. Samples were taken and the hydroxyl ions were analysed by acetate anhydrate method. The variables investigated in the present work were reaction temperatures varied from 230°C to 260°C and equivalent OH/COOH ratio from 1 to 1.25. Experimental results showed that alcoholysis of corn oil and glycerol could be carried out in a temperature range of 230°C to 260°C without the presence of catalyst. The effect of temperature on the reaction rate constant of monoglyceride and phthalic ester formation could be respectively written in the Arrhenius correlations as follows: k1 = 1.4647.104 exp (-8237.7/T) g/mgeq.min k4 = 2.1398.109 exp (-14142/T) g/mgeq.min Keywords: alcoholysis, esterification, corn oil, glycerol, phthalic anhydrate
Penentuan Tetapan Keseimbangan Penjerapan Pada Sistem Koloid Dengan Metode Ekstrapolasi Grafik H. satriadi; I. M. Bendiyasa; Rochmadi rochmadi
Reaktor Volume 6 No. 2 Desember 2002
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3440.529 KB) | DOI: 10.14710/reaktor.6.2.72-76

Abstract

Percobaan penjerapan pestisida pada sistem koloid air-tanah telah mendapatkan nilai tetapan keseimbangan penjerapan yang selalu berubah dan dipengaruhi perbandingan antara berat penjerap terhadap volum pelarutnya. Hal ini terjadi karena pemisahan antara penjerap dan pelarut sangat sulit dilakukan, dan pelarut selalu masih mengandung butir penjerap. Akibatnya  zat yang terjerap dalam penjerap ikut terbaca ketika menganalisis konsentrasi zat dalam pelarut. Untuk mendapatkan tetapan keseimbangan yang sebenarnya dapat dilakukan dengan modifikasi persamaan keseimbangan dan metode ekstrapolasi secara grafis. Percobaan dilakukan secara batch dengan konsentrasi awal pestisida sumithion 1,1014 ppm, perubahan konsentrasi diamati dengan kromatografi gas yang dilengkapi dengan Flame Photo Detector. Tanah yang digunakan berdiameter  butir 8,066. 10-5 cm, diameter pori 20,443 A, serta mengandung 2,86% bahan organic. Nilai tetapan keseimbangan sebenarnya diperoleh 123,936 ml air/g tanah pada 26,5 0C.Kata kunci : ekstrapolasi grafis, sistem koloid, tetapan keseimbangan penjerapan
PELUANG OLEORESIN JAHE SEBAGAI SUMBER BAHAN BAKU BERKELANJUTAN UNTUK OBAT-OBATAN Jayanudin Jayanudin; Rochmadi Rochmadi; Mohammad Fahrurrozi; Sang Kompiang Wirawan
JURNAL INTEGRASI PROSES VOLUME 8 NOMOR 2 DESEMBER 2019
Publisher : JURNAL INTEGRASI PROSES

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36055/jip.v8i2.6776

Abstract

Jahe oleoresin adalah produk dari rimpang jahe melalui proses ekstraksi menggunakan pelarut organik. Komponen aktif oleoresin jahe adalah sama dengan rimpang jahe seperti gingerol dan zingiberene sementara shogaol diperoleh dari proses dehidrasi selama penyimpanan dan ekstraksi. Bahan aktif seperti gingerol, shogaol, zingiberene dapat digunakan sebagai antioksidan, antiinflamasi, antimikroba, dan antikanker. Jahe oleoresin memiliki potensi besar untuk dikembangkan sebagai bahan baku alami dan berkelanjutan untuk industri farmasi
PENGARUH DOSIS DAN FREKUENSI PEMBERIAN PUPUK UREA TERHADAP PERTUMBUHAN DAN HASIL PETSAI DI BAWAH TEGAKAN SENGON UMUR 1,5 TAHUN ROCHMADI ROCHMADI; HARJANTO HARJANTO; HARYUNI HARYUNI
JURNAL ILMIAH AGRINECA Vol. 6 No. 2 (2006): Jurnal Agrineḉa
Publisher : Fakultas Pertanian, Universitas Tunas Pembangunan Surakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36728/afp.v6i2.225

Abstract

This Research porpose to know the effect of dose and gift frekuensi fertilize the urea and also interaction of both to growth and result of crop petsai (Brassica Pekinensis L) at strightened of sengon ( Paraserianthes Fakataria). Research have been executed at date of 28 March 2006 to 30 May 2006, in Countryside Tumenggungan, Subdistrict of Selomerto of Regency Wonosobo, Province of Central Java with the place height 850 m is above sea level. Research use the factorial method of elementary pattern of RAKL (Random Device of Complete Group) with two treatment factor that is 1) Dose fertilize the urea ( D) consisted of by 3 level : D1 50 kg / ha, D2 = 75 kg / ha, D3 = 100 kg / ha 2) Gift frekuensi fertilize the urea (F) consisted of by 3 level : F1 momentary before planting, F2 = frekuensi plant and after crop old age the two week, F3 = momentary before planting, after crop old age two and four weeks. Result of research show the 1) Dose treatment fertilize the urea have cm effect on very real at high of crop, sum up the leaf plant, fresh heavy of dry brangkasan plant weight and consume the plant 2) treatment of gift frekuensi fertilize to have an effect on very real to fresh weight of crop ready to consumption, heavy run dry the crop ready to consume, but do not have an effect on the reality differ is not real at high of crop, sum up the leaf plant. fresh heavy of brangkasan plant, and dry weight of brangkcisan plant 3) Interaction usher the treatment of dose and its gift frekuensi have an effect on the reality of at high of thy weight and crop of brangkasan plant of but having an effect on is not real to amount of leaf plant, fresh heavy of .fresh brangkasan plant weight and consume the plant 4) fresh Heavy of highest consumption 297,90 g /plant, obtained at combination of D3 F3 ( dose urea 100 kg / ha given momentary before planting, after crop old age two and four weeks). fresh Heavy consume the minimal 94,16 g/ plant obtained at combination of plant D1 F2 ( dose urea 50 kg / ha with the moment gift plant and after crop old age two week).
Kinetika Reaksi Alkyd Resin Termodifikasi Minyak Jagung dengan Asam Phtalat Anhidrat Heri Heriyanto; Rochmadi Rochmadi; Arief Budiman
Jurnal Rekayasa Proses Vol 5, No 1 (2011)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.1892

Abstract

Reaksi esterifikasi anhidrida phtalat dengan monogliserida merupakan reaksi kondensasi membentuk polimer dengan rantai linier. Penelitian ini bertujuan untuk mempelajari kinetika reaksi alkid resin termodifikasi minyak jagung tanpa menggunakan katalis. Proses penelitian ada dua tahap yaitu tahap pertama reaksi alkoholisis dan tahap kedua reaksi esterifikasi. Tahap alkoholisis diawali dengan mereaksikan minyak jagung dan gliserol dengan perbandingan molar 1:2 pada suhu 250°C. Sampel diambil pada selang waktu 30 menit selama 3 jam untuk dianalisis kadar gliserol bebasnya dengan metode iodometri (FBI-AO2-03). Tahap esterifikasi adalah mencampurkan anhidrida phtalat ke dalam reaktor batch dengan perbandingan molar gliserol : anhidrida phtalat 3:2. Sampel dianalisis kadar gugus OH- dengan metode asetat anhidrida. Peubah-ubah yang dipelajari meliputi variasi suhu dari 230°C – 260°C dan variasi perbandingan ekivalen OH/COOH dari 1 – 1,25. Berdasarkan hasil penelitian diambil kesimpulan bahwa minyak jagung dan gliserol dapat dialkoholisis tanpa menggunakan katalis pada kisaran suhu 230°C – 260°C. Pengaruh suhu terhadap konstanta kecepatan reaksi dinyatakan dengan persamaan Arrhenius adalah sebagai berikut : k1=1,4647×104 exp (-8237,7/T) (g/mgek.men) k4=2,1398×109 exp (-14142/T) (g/mgek.men) Kata kunci: alkoholisis, esterifikasi, minyak jagung, gliserol, anhidrida phtalat Esterification of phthalic anhydrate with monoglyceride is a condensation reaction to form a linear chain polymer. The present work aimed at investigating reaction kinetics of alkyd resin modified with corn oil in the absence of catalyst. The work consisted of two steps i.e. alcoholysis and esterification. In the alcoholysis step, corn oil and glycerol were brought into reaction with a molar ratio of 1:2 at 250°C. Every 30 minutes during 3 hour reaction, reaction products were sampled to analyse the remaining free glycerol by iodometry method (FBI-AO2-03). In the esterification step, phthalic anhydrate was put in the batch reactor with a glycerol-phthalic anhydrate molar of 3:2. Samples were taken and the hydroxyl ions were analysed by acetate anhydrate method. The variables investigated in the present work were reaction temperatures varied from 230°C to 260°C and equivalent OH/COOH ratio from 1 to 1.25. Experimental results showed that alcoholysis of corn oil and glycerol could be carried out in a temperature range of 230°C to 260°C without the presence of catalyst. The effect of temperature on the reaction rate constant of monoglyceride and phthalic ester formation could be respectively written in the Arrhenius correlations as follows: k1 = 1.4647.104 exp (-8237.7/T) g/mgeq.min k4 = 2.1398.109 exp (-14142/T) g/mgeq.min Keywords: alcoholysis, esterification, corn oil, glycerol, phthalic anhydrate
Pengujian Karakteristik Limbah Pasir PLTP Dieng Sebagai Bahan Pengisi Isolator Resin Epoksi Silane Abdul Syakur; Tumiran Tumiran; Hamzah Berahim; Rochmadi Rochmadi
Jurnal Rekayasa Elektrika Vol 9, No 4 (2011)
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (680.369 KB)

Abstract

Epoxy resin has been developed as an insulator material on the distribution and transmission line. In its development, the basic composition of DGEBA epoxy resin with MPDA as hardener is hydrophilic. Silane is added to improve the surface properties of materials to be more hydrophobic. To reduce the volume of epoxy resin as base material, silica sand from PLTP Dieng is added as filler. This paper presents the results of research on the effect of adding the composition of silica materials from PLTP Dieng upon silane epoxy resin sample to the value of the dielectric loss factor, contact angle and leakage current. Samples were prepared with a sample size 120mm x 50mm x 5mm. Material is composed of DGEBA, MPDA, silanes and silica with a various composition. Sample codes were 10%, 20%, 30%, 40% and 50%. Contact angle and leakage current were carried out according with IEC 587:1984 standards. Measurement of the dielectric loss factor (Tan ) was carried out at the Laboratory of High Voltage Engineering, PT. PLN (Persero) Electricity RD, Duren Tiga Jakarta, using a measuring instrument series M4100 Insulation Analyzer Instrument. The electrodes used in these measurements have diameter of 2.5 cm and 5 cm. The results showed that the composition of silica materials PLTP Dieng upon silane epoxy resin samples affect the value of dielectric loss factor. Based on the results of the measurement, it is concluded that the higher composition of silica materials, the higher value of dielectric loss factor are. Based on these results, it is suggested that the use of silica as a filler must consider the effect on the value of dielectric loss factor. When the dielectric loss factor is high, then the losses in the dielectric material is also high. 
SINTESIS PENTAERITRITOL ROSIN ESTER DARI GONDORUKEM DAN PENTAERITRITOL MENGGUNAKAN KATALIS ASAM HIPOFOSFOR Zen Adi Laksana; Rochmadi Rochmadi; Hary Sulistyo
Prosiding Sains Nasional dan Teknologi Vol 13, No 1 (2023): PROSIDING SEMINAR NASIONAL SAINS DAN TEKNOLOGI 2023
Publisher : Fakultas Teknik Universitas Wahid Hasyim

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36499/psnst.v13i1.9761

Abstract

Gondorukem yang diperoleh dari sadapan pohon pinus disebut gondorukem non-modifikasi yang memiliki kelemahan mudah teroksidasi oleh oksigen di udara terbuka. Oleh karena itu gondorukem perlu dimodifikasi untuk meningkatkan stabilitas oksidatifnya, salah satunya dengan metode esterifikasi. Pentaeritritol rosin ester merupakan produk turunan gondorukem yang dapat disintesis melalui esterifikasi gondorukem dengan pentaeritritol. Pentaeritritol Rosin Ester memiliki ketahanan air, ketahanan alkali, dan ketahanan oksidasi yang lebih baik  daripada gliserol rosin ester. Penelitian ini bertujuan untk mempelajari pengaruh suhu terhadap sintesis pentaeritritol rosin ester dari gondorukem dan pentaeritritol menggunakan katalis asam hipofosfor. Esterifikasi dilakukan dengan mereaksikan gondorukem dan pentaeritritol dengan rasio 100  : 12,5 dan asam hipofosfor sebanyak 0,2% dari massa gondorukem. Suhu reaksi divariasikan sebesar 260 – 290 °C dengan kecepatan agitasi sebesar 600 rpm. Pengambilan sampel dilakukan selama reaksi berlangsung, kemudian dianalisis angka asamnya menggunakan metode titrasi asam basa untuk menentukan konversi reaksi. Hasil penelitian menunjukkan bahwa semakin tinggi suhu reaksi, semakin tinggi pula konversi yang dicapai dan angka asam produk semakin rendah. Reaksi pada suhu 290 menghasilkan produk dengan konversi tertinggi yaitu sebesar 90,35 % dan angka asam terendah yaitu 17,38 mg KOH g-1. Namun tingginya suhu reaksi menyebabkan warna produk yang semakin gelap yang diindikasi karena meningkatnya laju reaksi dekarboksilasi.
Enhancing Justice Through Responsive Law in Indonesia Rochmadi Rochmadi; Zainal Arifin Hoesein
International Journal of Law, Crime and Justice Vol. 1 No. 4 (2024): December : International Journal of Law, Crime and Justice
Publisher : Asosiasi Penelitian dan Pengajar Ilmu Hukum Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.62951/ijlcj.v1i4.203

Abstract

Responsive law in Indonesia is an approach that aims to adapt the legal system to the dynamics and needs of a growing society. This article analyzes how the application of responsive law can improve justice and the effectiveness of law enforcement in Indonesia. The methodology used in this study includes a qualitative analysis of existing legal policies, in-depth interviews with legal practitioners, and case studies from several regions in Indonesia that apply the principles of responsive law. The results of the study indicate that the application of responsive law is not only able to answer emerging social challenges, but also strengthen the legitimacy of law in the eyes of the community. By integrating the values of justice and local needs in the law-making process, it is hoped that the Indonesian legal system will become more inclusive and responsive to community aspirations. This study recommends the development of more flexible and adaptive legal policies to ensure more equitable justice throughout Indonesia.
Co-Authors Abdul Syakur Ansar Ansar Arief Budiman Budhijanto Budhijanto Budi Rahardjo Eli Rohaeti H. satriadi Hamzah Berahim HARJANTO HARJANTO Hary Sulistyo Haryuni Heri Heriyanto I. M. Bendiyasa Jayanudin Jayanudin Mohammad Fahrurrozi Mujiyono Mujiyono Sang Kompiang Wirawan Tumiran YC. Danarto Zainal Arifin Hoesein Zen Adi Laksana Zuheid Noor