Article Per Year (5 Year)
p-Index From 2021 - 2026
4.447
P-Index
This Author published in this journals
All Journal Jurnal Transportasi Rekayasa Mesin Jurnal Rekayasa Mesin Journal of Energy, Mechanical, Material and Manufacturing Engineering CANTILEVER Jurnal Elemen Prosiding SNITP (Seminar Nasional Inovasi Teknologi Penerbangan) Jurnal Perkeretaapian Indonesia (Indonesian Railway Journal) E-Link: Jurnal Teknik Elektro dan Informatika International Journal of Mechanical Engineering Technologies and Applications (MECHTA) TEKIBA : Jurnal Teknologi dan Pengabdian Masyarakat Prosiding Seminar Nasional Sains Teknologi dan Inovasi Indonesia (Senastindo) Mechanical Engineering for Society and Industry Madiun Spoor : Jurnal Pengabdian Masyarakat Automotive Experiences Eksergi: Jurnal Teknik Energi Jurnal Pengabdian Kepada Masyarakat Semangat Nyata Untuk Mengabdi Journal of Railway Transportation and Technology Berkala Forum Studi Transportasi antar Perguruan Tinggi Jurnal Penelitian Transportasi Darat
Wirawan, Willy Artha
Universitas Negeri Surabaya, Indonesia
Aerospace Engineering Automotive Engineering Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Economics, Econometrics & Finance Electrical & Electronics Engineering Energy Engineering Environmental Science Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering Public Health Social Sciences Transportation Other

Published : 45 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 45 Documents
Search

 1   2   3   4   5 
Rekayasa Material Komposit Blok Rem Kereta Api Menggunakan Pasir Besi Ferro dan Serbuk Karbon Rahma, Muchamat Ardistiya; Apriliani, Nurul Fitria; Wirawan, Willy Artha
Berkala Forum Studi Transportasi antar Perguruan Tinggi Vol. 2 No. 3 (2024): Berkala Forum Studi Transportasi antar Perguruan Tinggi
Publisher : Prodi Teknik Sipil, Fakultas Teknik, Universitas Jember dan Forum Studi Transportasi antar Perguruan Tinggi

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/berkalafstpt.v2i3.1288

Abstract

The metallic and composite brake blocks have characteristics and advantages that need to be considered based on the needs and operational conditions of the railway. This study aims to determine the process of making composite brake blocks with carbon powder, iron sand, and epoxy resin and to understand their characteristics. Three variations of compositions, including 70 grams of epoxy resin + 15 grams of iron sand + 15 grams of carbon powder, 65 grams of epoxy resin + 15 grams of iron sand + 20 grams of carbon powder, and 55 grams of epoxy resin + 15 grams of iron sand + 30-gram carbon powder to produce distinct characteristic and properties. The fabrication of composite brake blocks was carried out using the vacuum infusion method. The tests conducted included hardness testing, wear testing, bending testing, and scanning electron microscope (SEM) analysis. The results ofthe tests showed thatthe hardness was 102.66 HRR, and the bending strength was 5985 N/cm^2, meetingthe standard for railway composite brake blocks. However, the wear test result of 1.81 x 10^-6 mm^2/kgdid not meet the standard value for the wear of railway composite brake blocks. ABSTRAK Blok rem metalik dan komposit memiliki karakteristik dan keunggulan masing – masing yang harus dipertimbangkan berdasarkan kebutuhan dan kondisi operasional kereta api. Penelitian ini bertujuan untuk mengetahui proses pembuatan blok rem komposit dengan serbuk karbon, pasir besi, dan resin epoxy serta untuk mengetahui karakteristiknya. Pada penelitian ini menggunakan 3 variasi komposisi meliputi 70 gram resin epoxy + 15 gram pasir besi + 15 gram serbuk karbon, 65 gram resin epoxy + 15gram pasir besi + 20 gram serbuk karbon, dan 55 gram resin epoxy + 15 gram pasir besi + 30 gram serbuk karbon untuk menghasilkan karakteristik dan sifat yang berbeda. Pembuatan blok rem komposit menggunakan metode vacuum infusion. Pengujian yang dilakukan meliputi pengujian kekerasan, keausan, bending, dan scanning electron microscope (SEM). Hasil dari pengujian menunjukkan bahwakekerasan sebesar 102,66 HRR dan uji bending sebesar 5985 N/??2 memenuhi standar dari blok rem komposit kereta api, tetapi untuk uji keausan sebesar 1,81 x 10-6 mm2/kg tidak memenuhi standar nilaikeausan blok rem komposit kereta api.
Mechanical behavior of glass fiber-epoxy composite laminates for ship hull structures Gunarti, Monika Retno; Prawoto, Agus; Fauzi, Wahyu Nur; Wirawan, Willy Artha
Mechanical Engineering for Society and Industry Vol 4 No 2 (2024)
Publisher : Universitas Muhammadiyah Magelang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31603/mesi.11589

Abstract

Polymer composite is widely used in various structures due to its strength-to-load ratio. Despite the significant benefits, many structures are vulnerable to high-impact loads in practical situations. Therefore, this research aimed to explore the effect of fiber arrangement on the mechanical behavior of glass fiber-epoxy composite laminates. Experiments were conducted on several samples with glass fiber arrays of Chopped Strand Matt (CSM), Woven Rovings (WR), and Woven Cloth (WC). The composite fabrication was molded using the vacuum pressure infusion (VAPRI) method. The mechanical behavior of laminate composite was obtained using a tensile test, tree point bending, shore D hardness, Charrpy impact, fracture observation, and fiber-matrix delamination. The results showed that WR arrangement excelled in various mechanical behaviors, including flexural strength 6992.6 Mpa, Hardnes 75.66 HD, and Impact 0.1789 J/mm. In comparison, the highest tensile strength value was obtained in the WC arrangement of 73.24 Mpa. This research showed that both regular and arranged fiber provided better mechanical properties than random fiber. The incorporation of fiber arrangement could be recommended in the further development of high-performance polymer composite.
ECO – INNOVATIVE CARBURIZING: ENHANCING STEEL ST 37 WITH ALABAN CHARCOAL AND EGGSHELL CATALYSTS Ahmad Robittah; Suprapto, Wahyono; Widodo, Teguh Dwi; Wirawan , Willy Artha; Sabitah, A’yan
International Journal of Mechanical Engineering Technologies and Applications Vol. 6 No. 1 (2025)
Publisher : Mechanical Engineering Department, Engineering Faculty, Brawijaya University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/MECHTA.2025.006.01.13

Abstract

This study examines the enhancement of St 37 steel through an eco-friendly carburization process using Alaban charcoal and eggshell catalyst. The agriculture sector in South Kalimantan, Indonesia, depends largely on metal tools made from low-carbon steel, which need greater hardness and durability. Traditional carburization techniques are costly and often lead to uneven carbon distribution. This research investigates the use of Alaban wood charcoal and local duck eggshell waste as carburizing agents. The experiment involved varying the weight ratio of charcoal to eggshell powder, then carburizing at 950°C for two hours, followed by water quenching. The results indicated a notable increase in surface carbon content, diffusion depth, hardness, and microstructure of St 37 steel. The optimal combination, achieving the highest surface hardness of 947 HV and a carbon diffusion depth of 1.0 mm, was found at an eggshell catalyst concentration of 30%. All samples exhibited a microstructural change to martensite. These results demonstrate the potential of using agricultural waste to enhance steel properties, promoting more sustainable and cost-effective industrial practices.
Pengembangan Keterampilan Las Listrik SMAW Pada Siswa Sekolah Menengah Kejuruan (SMK) Di Workshop Politeknik Penerbangan Surabaya Prayitno, Hadi; Bahrawi, Ahmad; Suyatmo; Wirawan, Willy Artha; Sakti, Gunawan; Pambudiyanto, Nyaris; Wulansari, Ajeng
TEKIBA : Jurnal Teknologi dan Pengabdian Masyarakat Vol. 4 No. 2 (2024): TEKIBA : Jurnal Teknologi dan Pengabdian Masyarakat
Publisher : Fakultas Teknik, Universitas PGRI Banyuwangi

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36526/tekiba.v4i2.4667

Abstract

This study aims to achieve several results that contribute to improving the community's ability regarding welding techniques that are currently in great demand by various industries. The method used is a qualitative method with observation used to understand in depth how SMAW (Shielded Metal Arc Welding) electric welding skills are developed in vocational high school students. The sample in this study was the Community Service Activity Implementation Team for the Development of SMAW Electric Welding Skills for Vocational High School (SMK) Students at the Surabaya Aviation Polytechnic Workshop in the 2024 Fiscal Year consisting of 16 people, the results of the study showed that the Development of SMAW Electric Welding Skills has improved the abilities of students of SMK Penerbangan AAG Yogyakarta, SMK Penerbangan Angkasa Lanud Iswahjudi Magetan, SMK Penerbangan Angkasa Malang, even providing new experiences for students from the Computer and Network Engineering department. Based on the results of the activity, the participants showed significant progress in knowledge and skills. Increasing knowledge and skills through the approach of educational materials and technical training provided, participants in this activity have learned the benefits, placement, procedures and how to use SMAW Electric welding correctly and safely. Almost all participants of this activity agreed that SMAW Electric Welding can help improve skills both in education and industry. Empowerment of Aviation Vocational School students in developing SMAW Electric Welding skills is expected to be applied in various industrial fields by providing several examples of how to use SMAW Electric Welding.
Perancangan Sistem Peringatan Longsor dan Deteksi Pergeseran Tanah Menggunakan Metode Telemetri Sunardi Sunardi; Teguh Arifianto; Anindira Listy Hartisa; Arief Darmawan; Willy Artha Wirawan
Jurnal Penelitian Transportasi Darat Vol. 22 No. 2 (2020): Jurnal Penelitian Transportasi Darat
Publisher : Sekretariat Badan Kebijakan Transportasi, Formerly by Puslitbang Transportasi Laut, Sungai, Danau, dan Penyeberangan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25104/jptd.v22i2.1618

Abstract

ABSTRACTDesign of Landslide Potential Warning System and Land Shifting Using Telemetry Method: According to the 2019 BNBP Performance Report, landslides are the fourth most frequent disaster in Indonesia, so we need a telemetry tool for land shifting. This system consists of ATMega328 Microcontroller, Linear Variable Differential Transformer sensor and rheostat, accelerometer sensor, rain gauge tipping bucket, and HC-12 wireless communication module. Normally, LVDT sensor reads ground shift in the 0-20 mm range, rheostat shifting up to 66 mm, accelerometer sensor reads data less than 20 deg and  rain gauge tipping bucket sensor generates the amount of rainfall below 50 mm/hour which is sent data regularly to user. Warning alarms installed in these prone area will sound if the LVDT sensor reads ground shift>30 mm, rheostat>51 mm, accelerometer sensor reads data more than 45°, and rain gauge tipping bucket sensor reads more than 70 mm/hour. This test produces measurable parameter data so that it can be displayed and provide warning information.Keywords: alarm warning; ATMega 328; land shifting; landslides; telemetry.ABSTRAKMenurut Laporan Kinerja BNBP 2019, tanah longsor merupakan bencana yang sering terjadi urutan keempat di Indonesia, sehingga perlu suatu alat telemetri terhadap pergeseran tanah. Sistem ini terdiri atas Mikrokontroler ATMega328, sensor Linear Variable Differential Transformer dan rheostat, sensor accelerometer, sensor rain gauge tipping bucket, dan modul komunikasi wireless HC-12. Normalnya, sensor LVDT membaca pergeseran tanah pada range 0-20 mm, rheostat mampu melakukan pergeseran hingga 66 mm, sensor accelerometer membaca data kurang dari 20 deg, dan sensor rain gauge tipping bucket menghasilkan jumlah curah hujan dibawah 50 mm/jam yang kemudian data dikirim secara rutin ke user. Alarm peringatan yang terpasang di daerah rawan tersebut akan berbunyi jika sensor LVDT membaca pergeseran tanah >30 mm, rheostat >51 mm, sensor accelerometer membaca data lebih dari 45 derajat, dan sensor rain gauge tipping bucket membaca data lebih dari 70 mm/jam. Pengujian ini menghasilkan data parameter yang terukur sehingga dapat ditampilkan dan memberikan informasi peringatan.Kata Kunci: alarm peringatan; ATMega 328; pergeseran tanah; tanah longsor; telemetri
ECO – INNOVATIVE CARBURIZING: ENHANCING STEEL ST 37 WITH ALABAN CHARCOAL AND EGGSHELL CATALYSTS Ahmad Robittah; Suprapto, Wahyono; Widodo, Teguh Dwi; Wirawan , Willy Artha; Sabitah, A’yan
International Journal of Mechanical Engineering Technologies and Applications Vol. 6 No. 1 (2025)
Publisher : Mechanical Engineering Department, Engineering Faculty, Brawijaya University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/MECHTA.2025.006.01.13

Abstract

This study examines the enhancement of St 37 steel through an eco-friendly carburization process using Alaban charcoal and eggshell catalyst. The agriculture sector in South Kalimantan, Indonesia, depends largely on metal tools made from low-carbon steel, which need greater hardness and durability. Traditional carburization techniques are costly and often lead to uneven carbon distribution. This research investigates the use of Alaban wood charcoal and local duck eggshell waste as carburizing agents. The experiment involved varying the weight ratio of charcoal to eggshell powder, then carburizing at 950°C for two hours, followed by water quenching. The results indicated a notable increase in surface carbon content, diffusion depth, hardness, and microstructure of St 37 steel. The optimal combination, achieving the highest surface hardness of 947 HV and a carbon diffusion depth of 1.0 mm, was found at an eggshell catalyst concentration of 30%. All samples exhibited a microstructural change to martensite. These results demonstrate the potential of using agricultural waste to enhance steel properties, promoting more sustainable and cost-effective industrial practices.
RANCANG BANGUN PEMBANGKIT LISTRIK TENAGA MIKROHIDRO (PLTMH) POLITEKNIK PERKERETAAPIAN INDONESIA MADIUN Akhwan, Akhwan; Gunari, Bambang; Sunardi, Sunardi; Wirawan, Willy Artha
Eksergi Vol. 17 No. 1 (2021): JANUARI 2021
Publisher : Politeknik Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (594.748 KB) | DOI: 10.32497/eksergi.v17i1.2168

Abstract

Rancang bangun pembangkit listrik tenaga mikro hidro (PLTMH) adalah rancangan pembangkit listrik dengan memanfaatkan tenaga air yang bersumber dari saluran tandon air yang berada di Politeknik Perkeretaapian Indonesia Madiun, Jawa Timur. Pada penelitian ini bertujuan untuk membuat rancang bangun sederhana pembangkit mikro hidro yang dilengkapi dengan alternative antara tenaga air (mikrohidro) dan tenaga panas dari matahari (panel surya). Metode penelitian ini menggunakan rancang bangun dengan membuat prototype alat, kemudian dilakukan beberapa parameter penggunaan turbin dan panel surya. Berdasarkan hasil penelitian diperoleh debit air yang tersedia di lokasi sebesar 14 liter/menit. Kemudian dari hasil pengukuran daya pembangkit diketahui bahwa, pembangkit listrik tenaga mikro hidro generator 12 Volt dapat menghasilkan tegangan sebesar 13.18 Volt dengan arus rata-rata sebesar 102.2 mA. Pembangkit listrik tenaga mikro hidro pada generator 80 Volt dapat menghasilkan tegangan 17.27 Volt dengan arus rata-rata 129 mA. Sedangkan alternatif cadangan pembangkit listrik menggunakan panel surya dapat menghasilkan arus sebesar 20.406 Volt dan arus 0.736 A
Investigasi Penambahan Betaine pada Media Quenching Surface Treatment untuk Meningkatkan Nilai Kekerasan Rel Kereta Api UIC R54 Rozaq, Fadli; Wahjono, Hari Boedi; Putra, Rafli Rianzah; Wirawan, Willy Artha; Effendy, Marwan
Jurnal Rekayasa Mesin Vol. 19 No. 1 (2024): Volume 19, Nomor 1, April 2024
Publisher : Mechanical Engineering Department - Semarang State Polytechnic

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32497/jrm.v19i1.4726

Abstract

Penelitian ini bertujuan untuk menginvestigasi tingkat keefektifan penambahan betaine pada media quenching dalam proses surface treatment di rel kereta api tipe UIC R54. Metode yang digunakan pada penelitian ini yaitu diawali dengan perlakuan surface treatment pada rel dibagian permukaannya. Media quenching yang dipakai adalah campuran air dengan betaine dengan perbandingan 65%:35%. Spesimen rel yang sudah mendapat perlakuan selanjutnya dilakukan pengukuran nilai kekerasan permukaan dan pengamatan struktur mikro. Nilai kekerasan raw material rel menunjukan angka 283,52 BHN. Pada spesimen yang telah mendapat perlakuan, nilai kekerasannya menunjukan angka 297,97 BHN. Fasa yang terbentuk pada spesimen raw material rel didominasi oleh pearlite dan ferrite. Untuk fase yang terbentuk pada spesimen yang telah mendapat perlakuan adalah martensite. Kesimpulan dari penelitian ini adalah camputan betaine 35% dengan air 65% sebagai media quenching pada proses surface treatment memberikan hasil yang baik untuk menambah kekerasan permukaan rel.
REVIEW: VARIOUS TREATMENTS NAOH, SEA WATER, FUMIGATION, LIQUID SMOKE TO IMPROVE TENSILE STRENGTH AND SURFACE MORPHOLOGY OF NATURAL FIBER Muslimin, Mukhlis; Wirawan, Willy Artha; Palungan, Musa Bondaris
Jurnal Rekayasa Mesin Vol. 15 No. 2 (2024)
Publisher : Jurusan Teknik Mesin, Fakultas Teknik, Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/jrm.v15i2.1600

Abstract

This article is a literature review of several studies oriented toward the treatment of natural fiber to improve the surface morphology and tensile strength of the fiber. The method used is to review several studies that describe the physical and mechanical properties of natural fiber with different treatments such as immersion of sago fiber in liquid smoke, coconut fiber in NaOH, palm fiber in seawater, and smoking of king pineapple fiber, and banana stem fiber with liquid smoke. The results of the review showed that the treatment was able to increase the tensile strength of sago fiber by 26.77%, coconut fiber by 81.25%, palm fiber by 67.40%, waru bark fiber by 59,97%, coconut fiber with limestone water 34,96 %, king pineapple fiber by 74.45%, and banana stem fiber by 43.78%. The effect of some of these treatments can also change the morphology of the fiber. So, it was concluded that treatment was needed to change the physical properties of the fiber in the form of morphology and mechanical properties in the form of better fiber tensile strength so that the fiber used as a composite reinforcement could improve the mechanical properties of the composite.
ANALISIS PERBANDINGAN LEAN CONCRETE DAN CEMENT TREATED BASE (CTB) SEBAGAI LAPISAN STABILIZED BASE MENGGUNAKAN SOFTWARE FAARFIELD UNTUK PERLUASAN APRON B DI BANDAR UDARA DJALALUDDIN GORONTALO Artha Wirawan, Willy; Rozi, Fahrur; Luqman Afandi, Muhammad
Prosiding SNITP (Seminar Nasional Inovasi Teknologi Penerbangan) Vol. 9 No. 1 (2025): SNITP 2025
Publisher : Politeknik Penerbangan Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Apron B Bandar Udara Djalaluddin Gorontalo merupakan area strategis untuk pergerakan pesawat yang direncanakan diperluas sebesar 38.016 m² untuk mendukung status Embarkasi Haji Penuh (EHP) sehingga harus mampu melayani Pesawat Boeing 777 300ER. Salah satu komponen penting perkerasan kaku adalah lapisan stabilized base, di mana dua material yang umum digunakan yaitu lean concrete dan cement treated base (CTB) harus dievaluasi untuk menentukan opsi yang paling optimal dan efisien dari segi struktur dan ekonomi. Metode yang digunakan dalam penelitian ini adalah metode kuantitatif komparatif, yang dilakukan dengan mengolah data numerik serta membandingkan dua jenis material stabilized base melalui simulasi menggunakan software FAARFIELD. Analisis dilakukan untuk memperoleh hasil perbandingan ketebalan struktur perkerasan, nilai PCN, serta estimasi biaya konstruksi. Hasil analisis menunjukkan bahwa struktur dengan lean concrete memiliki total ketebalan 793 mm dan menghasilkan nilai PCN sebesar 117 R/B/W/T, sedangkan struktur dengan CTB memiliki total ketebalan 795 mm dengan nilai PCN 118 R/B/W/T. Dari sisi biaya, rencana anggaran biaya untuk struktur perkerasan kaku apron B dengan menggunaan lean concrete pada lapisan stabilized base mencapai Rp 96,406,624,950, sedangkan penggunaan CTB lebih ekonomis sebesar Rp 95,350,273,103. Kedua alternatif memenuhi syarat kekuatan struktur (PCN > ACN), namun CTB menawarkan kombinasi terbaik antara performa dan efisiensi biaya untuk lapisan stabilized base Apron B.
Co-Authors ,, Sunardi Achfas Zacoeb Achmad Sholih Zidni Adya Aghastya Adya aghastya Aghastya, Adya Ahmad Bahrawi, Ahmad Ahmad Hamim Suudy Akbar Zulkarnain Akbar Zulkarnain Akhwan Akhwan Akhwan, Akhwan Akwan, Akwan Aldi Wardana Aldri Frinaldi Allan E.W. Rennie Anindira Listy Hartisa Anindito Purnowidodo Arief Darmawan Ary Putra Iswanto Astuti, Septiana Widi A’yan Sabitah Balla Wahyu Budiarto Bambang Junipitoyo Dadang Sanjaya Atmaja Damayanti, Ajeng Tyas Dhina Setyo Oktaria Diah Wulandari Diva Kurnianingtyas Edi Nyoto Setyo Marsusiadi Ekananta, Krisna Pramudya Ependi, Ahmad Fadli Rozaq Fadli Rozaq Fadli Rozaq Fahrur Rozi Fauzi, Wahyu Nur Febri Pandu Wijaya Gembong Edhi Setyawan Gunari, Bambang Gunarti, Monika Retno Hadi Prayitno Handoko Handoko Hari Boedi Wahjono Harus Laksana Guntur Imam Kusyairi Imron, Nanda Ahda Iswanto, Ary Putra Johan Wayan Dika Lailya, Alvi Lutfyani Luqman Afandi, Muhammad Marwan Effendy Moch. Agus Choiron Moch. Agus Choiron Moch. Agus Choiron Mukhlis Muslimin Muslimin, Mukhlis Nanda Ahda Imron Natriya Faisal Rachman Natriya Faisal Rachman Nurul Fitria Apriliani Oki Kurniawan Palungan, Musa Bondaris Pambudi, Ardhenta Sigit Pambudiyanto, Nyaris Pegah Hamedani Pradipta, Andri Prawoto, Agus Puspitasari, Mariana Diah Putra, Rafli Rianzah Rachman, Natriya Faisal Rafli Rianzah Putra Rahma, Muchamat Ardistiya Rezki Putra Ridwan Ridwan Robittah, Ahmad Rosadila Febritasari Royyan Ghozali Rozaq, Fadli Rozaq, Fadli Sabitah, A'yan Sakti, Gunawan Santi Triwijaya Septiana Widi Astuti Setyo Hariyadi Suranto Putro Sigit Tri Wicaksono Sofyan Arief Sofyan Arief Setyabudi Sunardi Sunardi sunardi sunardi Sunardi Sunardi Suprapto Suprapto Suyatmo Teguh Arifianto Teguh Dwi Widodo Wahyono Suprapto Wahyu Tamtomo Adi Wahyu Tamtomo Adi, Wahyu Tamtomo Widodo, Teguh Dwi Wulansari, Ajeng Yudhi Ariadi Yustina Titin Purwantiningsih Zulkarnaen, Akbar Zulkarnain, Akbar