Article Per Year (5 Year)
p-Index From 2020 - 2025
0.92
P-Index
This Author published in this journals
All Journal Journal of Tropical Soils Jurnas Nasional Teknologi dan Sistem Informasi JURNAL NASIONAL TEKNIK ELEKTRO AGRITROPICA : Journal of Agricultural Sciences Jurnal Sains Agro Jurnal Rekayasa elektrika
Darmawan, Darmawan
Andalas University
Agriculture, Biological Sciences & Forestry Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Electrical & Electronics Engineering Energy Engineering Environmental Science

Published : 13 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 13 Documents
Search

 1   2 
Perancangan Sensor Gerak Benda pada Benturan Berlebihan untuk Pengujian Pre-Straining Spring Momentum Exchange Impact Dumper (PSMEID) Dengan Metoda Prediksi Waktu Benturan (Preview) Darmawan, Darmawan; Lovelyson, Lovelyson; Pharmayeni, Pharmayeni
JURNAL NASIONAL TEKNIK ELEKTRO Vol 9, No 3: November 2020
Publisher : Jurusan Teknik Elektro Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (585.031 KB) | DOI: 10.25077/jnte.v9n3.713.2020

Abstract

Vibration that occurs due to excessive impact can damage the construction of an object. Excessive Impact which usually occurs at certain times such as aircraft landing gear collisions with runways that can be fatal if the vibrations produced cannot be controlled properly. One method to reduce vibration caused by excessive impact is called PSMEID (Pre-Straining Momentum Exchange Impact Dumper), which in this case utilizes momentum from a period placed in the main period in which the direction of the style is opposite to the force produced by the collision. In previous studies the PSMEID system was activated shortly after the collision, due to the absence of a sensor mechanism to detect the vibrations and movements of objects that occur. In this case, this research tries to design a sensor system that can detect the movement of objects before an Excessive impact occurs. By knowing the position and condition of the object just before the collision, it can be predicted the time of the collision so that the time of mass release with a spring push that has been stretched (pre-straining) in the opposite direction from the direction of collision gives more optimal results to reduce vibrations from the collision. This study designed various of sensors system consisting of vibration sensors, acceleration sensors and proximity sensors that work in such a way that the PSMEID activation time is close to / equal to the time of the initial collision so that momentum and acceleration can be reduced. In the initial testing this sensor system only involves vibration sensor, where PSMEID can be activated 32 millisecond.Keywords : Excessive Impact, PSMEIDAbstrakGetaran yang terjadi diakibatkan oleh benturan  yang berlebihan (Excessive Impact) dapat merusak kontruksi sebuah benda. Excessive Impact yang biasanya terjadi pada waktu tertentu saja seperti benturan roda pendaratan pesawat dengan landasan pacu yang dapat berakibat fatal jika getaran yang dihasilkan tidak dapat dikontrol dengan baik. Salah satu metoda untuk mereduksi getaran yang diakibatkan dari (Excessive Impact) disebut sebagai PSMEID (Pre-Straining Momentum Exchange Impact Dumper), dimana dalam hal ini memanfaat momentum dari sebuah masa yang ditempatkan pada masa utama yang arah gayanya berlawanan dengan gaya yang dihasilkan oleh benturan. Pada penelitian sebelumnya system PSMEID diaktifkan sesaat setelah terjadinya benturan, karena tidak adanya mekanisme sensor untuk mendeteksi vibbrasi dan pergerakan benda yang terjadi. Maka dalam hal ini, penelitian ini mencoba merancang sistem sensor yang dapat mendeteksi pergerakan benda sebelum terjadinyanya Excessive impact. Dengan mengetahui posisi dan kondisi benda sesaat sebelum terjadi benturan maka dapat diprediksi waktu benturan sehingga waktu pelepasan massa dengan dorongan pegas yang sudah diregangkan (pre-straining) dengan arah yang berlawanan dari arah benturan memberikan hasil yang lebih optimal untuk mereduksi getaran dari benturan yang terjadi. Penelitian ini merancang system multinsensor yang terdiri dari sensor vibrasi, sensor percepatan dan sensor jarak yang bekerja sedekian rupa sehingga waktu aktifasi PSMEID mendekati/sama dengan waktu terjadinya benturan awal sehingga momentum dan percepatan dapat direduksi. Pada pengujian awal system sensor ini hanya melibatkan sensor vibrasi saja, dimana PSMEID mampu diaktifkan 32 ms.Kata Kunci : Excessive Impact, PSMEID
Web-based Monitoring System for Power Electronics Devices on Off-grid Solar Power Generator Luthfi, Amirul; Waldi, Eka Putra; Darmawan, Darmawan; Baharudin, Baharudin; Sunaryo, Budi
JURNAL NASIONAL TEKNIK ELEKTRO Vol 10, No 1: March 2021
Publisher : Jurusan Teknik Elektro Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (310.639 KB) | DOI: 10.25077/jnte.v10n1.851.2021

Abstract

Power electronic devices are the main component of the solar power generation system. This study proposes a web-based monitoring system which presents power electronic performance parameter in a real-time across an internet connection. The investigation takes ACS712 and PZEM-004T for the power converter performance measuring and Arduino Mega 2560 with an ethernet shield for data acquisition and transmission. This paper describes the schematic design of the hardware and also explains the software work-flow and structure. The test and calibration on the sensor's voltage and current to standard digital multi-meter Tektronix DMM4050 show the sensor able to accurately read the converter performance parameter and meet the standard IEC-61724. The functionality test on the web-based information system indicates the designed user interface to present the power electronic performance parameter of the solar power generator.Keywords: Monitoring System, Power Electronics and Solar Power
Analisa Perbandingan Quality of Service Voice Over IP dengan Pengujian Codec Menggunakan Algoritma Low Latency Queuing Darmawan Darmawan; Yayan Syafriyatno
Jurnal Nasional Teknologi dan Sistem Informasi Vol 3, No 2 (2017): Agustus 2017
Publisher : Jurusan Sistem Informasi, Fakultas Teknologi Informasi, Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/TEKNOSI.v3i2.2017.249-254

Abstract

Voice over IP (VoIP) adalah solusi komunikasi suara yang murah karena menggunakan jaringan IP dibanding penggunaan telephone analog yang banyak memakan biaya. Dalam penerapannya, VoIP mengalami permasalahan karena menggunakan teknologi packet switching yang mana penggunaannya bersamaan dengan paket data sehingga timbul delay, jitter, dan packet loss.  Pada penelitian ini, algoritma Low Latency Queuing (LLQ) diterapkan pada router cisco. Algoritma LLQ merupakan gabungan dari algoritma Priority Queuing (PQ) dan Class Based Weight Fair Queuing (CBWFQ) sehingga dapat memprioritaskan paket suara disamping paket data. Algoritma LLQ ini diujikan menggunakan codec GSM FR, G722, dan G711 A-law. Hasil pengujian didapatkan nilai parameter yang tidak jauh berbeda dan memenuhi standar ITU-T.G1010. Nilai delay rata - rata terendah yaitu ketika menggunakan codec G722 sebesar 20,019 ms tetapi G722 memiliki rata - rata jitter yang terbesar yaitu 0,986 ms.  Codec dengan jitter rata – rata terkecil adalah G711 A-law sebesar 0,838 ms. Packet loss untuk semua codec yang diujikan adalah 0%.  Throughput pada paket data terbesar saat menggunakan codec GSM FR yaitu 18,139 kbps. Codec yang direkomendasikan adalah G711 A-law karena lebih stabil dari segi jitter dan codec GSM FR cocok diimplementasikan pada jaringan yang memiliki bandwitdh kecil.
Analisa Link Balancing dan Failover 2 Provider Menggunakan Border Gateway Protocol (BGP) Pada Router Cisco 7606s Darmawan Darmawan; Teguh Imanto
Jurnal Nasional Teknologi dan Sistem Informasi Vol 3, No 3 (2017): Desember 2017
Publisher : Jurusan Sistem Informasi, Fakultas Teknologi Informasi, Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/TEKNOSI.v3i3.2017.326-333

Abstract

Sistem link balancing dan failover merupakan salah satu cara yang dapat digunakan untuk membagi beban traffic dari client pada beberapa koneksi internet, dapat sebagai backup/failover ketika salah satu koneksi internet mengalami gangguan. Pada perancangan sistem ini digunakan 4 buah router, yaitu terdiri dari satu router cisco 7606s yang berfungsi sebagai main gateway yang mengatur sistem failover dan link balancing menuju ke 2 buah router mikrotik RB951G 2HND sebagai jalur kedua ISP dan router mikrotik CCR1036-12G-4S sebagai gateway dari FTP server. Tiap router tersebut memiliki Autonomus System Number yang berbeda yang saling berkomunikasi menggunakan routing Border Gateway Protocol (BGP). Dari hasil pengujian penggunaan link balancing dengan besar bandwidth 10 mb/s, didapatkan throughput 794 KB/s, sedangkan yang tidak menggunakan link balancing dengan bandwidth sebesar 20 mb/s, didapatkan nilai throughput hanya 136 KB/s. Penggunaan link balancing dapat memanfaatkan besar bandwidth yang ada dan meningkatkan throughput, dibandingkan tidak menggunkan link balancing. Pada pengujian delay, menggunakan link balancing hanya delay 1.24 ms, sedangkan tidak menggunakan metode link balancing mencapai 8.19 ms. Nilai latency didapatkan 12 ms untuk menggunakan link balancing sedangkan tidak menggunkan metode link balancing mencapai 1896 ms.
Nitrogen and Phosphorous Movement Characteristic in Terrace Paddy Field Using Cascade Irrigation System in West Sumatra, Indonesia . Darmawan; Syafrimen Yasin; Tsugiyuki Masunaga
JOURNAL OF TROPICAL SOILS Vol 16, No 2: May 2011
Publisher : UNIVERSITY OF LAMPUNG

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5400/jts.2011.v16i2.129-138

Abstract

West Sumatra is one of Indonesian rice bowl. The landscape of this province dominated by mountainous area with beautiful terrace paddy field lied from the middle slope to the lowland. The most common rice cultivation management in this area is application of cascade irrigation system with blanked amount of chemical fertilizer application. This study intends to figure out, whether this kind of paddy field management sustains and friendly to the environment or not. The results showed that cascade irrigation system created some discrepancies in suspended solid (SS), dissolve organic matter (DOM) and the nutrient movement characteristic a long the slope. The SS and DOM load and discharge strongly influenced by land preparation activities, while total and available nitrogen (N) and phosphorous (P) affected by chemical fertilizer application. In the upper part, the amount of chemical fertilizer seemed sufficient, indicated by negative amount of nutrient balance, while lower terrace show some indication of excess nutrient input. To avoid some demerit of cascade irrigation system, chemical fertilizer application should be base on site specific characteristic and taking into account of natural source contribution.Keywords: Cascade irrigation, chemical fertilizer, nutrient balance, terrace paddy field
Changes of Soil Properties on Various Ages of Rubber Trees in Dhamasraya, West Sumatra, Indonesia Syafrimen Yasin; . Adrinal; . Junaidi; Erick Wahyudi; Silvia Herlena; . Darmawan
JOURNAL OF TROPICAL SOILS Vol 15, No 3: September 2010
Publisher : UNIVERSITY OF LAMPUNG

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5400/jts.2010.v15i3.221-227

Abstract

Changes of Soil Properties on Various Ages of Rubber Trees in Dhamasraya, West Sumatra, Indonesia (S Yasin, Adrinal, Junaidi, E Wahyudi, S Herlena and Darmawan): Although rubber has been planted in Indonesia from Holland era, but there is little information about the effect of rubber plantation on the rate of land degradation in Indonesia.  In order to examine the effect of rubber tree (Hevea brasiliansis) ages on land degradation status, a series experiment was done in Dhamasraya district as the main contributor of natural rubber in West Sumatra, Indonesia. Study site divide  into forest (A), crab grass (B), and rubber plantation with ages ranged from 1 (C), 5 (D), 10 (E), 15 (F) and 20 (G) years were selected as study sites and soil samples had been taken from each site, where forest soil  was used as a control. The result proved that the age of rubber tree has strongly affected physical and chemical properties of soil. Organic carbon and total nitrogen content decreased from 3.02%, 2.66%, 1.96%, in site A, B and C, and then increased to 2.33% and 2.49% in site D and E, respectively. This result was opposed with bulk density (BD) value of each site. The highest BD found in site C (1.26 g cm-3), followed by site D, E, B and A with 1.24, 1.14, 1.12 and 0.88 g cm-3, respectively. The similar pattern was also found for selected chemical properties of soil. Soil pH, available phosphorous, exchangeable base cations, cation exchange capacity and base saturation was likely to decrease from 1 to 10 years old plantation and then increased close the natural condition (reflected by forest soil) at 20 years old rubber tree. Since most of plantation was conversed from natural forest, this phenomenon might be because of contribution of organic matter from original condition and addition of fertilizer at the beginning of plantation establishment.
Perancangan Sensor Gerak Benda pada Benturan Berlebihan untuk Pengujian Pre-Straining Spring Momentum Exchange Impact Dumper (PSMEID) Dengan Metoda Prediksi Waktu Benturan (Preview) Darmawan Darmawan; Lovelyson Lovelyson; Pharmayeni Pharmayeni
JURNAL NASIONAL TEKNIK ELEKTRO Vol 9, No 3: November 2020
Publisher : Jurusan Teknik Elektro Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (585.031 KB) | DOI: 10.25077/jnte.v9n3.713.2020

Abstract

Vibration that occurs due to excessive impact can damage the construction of an object. Excessive Impact which usually occurs at certain times such as aircraft landing gear collisions with runways that can be fatal if the vibrations produced cannot be controlled properly. One method to reduce vibration caused by excessive impact is called PSMEID (Pre-Straining Momentum Exchange Impact Dumper), which in this case utilizes momentum from a period placed in the main period in which the direction of the style is opposite to the force produced by the collision. In previous studies the PSMEID system was activated shortly after the collision, due to the absence of a sensor mechanism to detect the vibrations and movements of objects that occur. In this case, this research tries to design a sensor system that can detect the movement of objects before an Excessive impact occurs. By knowing the position and condition of the object just before the collision, it can be predicted the time of the collision so that the time of mass release with a spring push that has been stretched (pre-straining) in the opposite direction from the direction of collision gives more optimal results to reduce vibrations from the collision. This study designed various of sensors system consisting of vibration sensors, acceleration sensors and proximity sensors that work in such a way that the PSMEID activation time is close to / equal to the time of the initial collision so that momentum and acceleration can be reduced. In the initial testing this sensor system only involves vibration sensor, where PSMEID can be activated 32 millisecond.Keywords : Excessive Impact, PSMEIDAbstrakGetaran yang terjadi diakibatkan oleh benturan  yang berlebihan (Excessive Impact) dapat merusak kontruksi sebuah benda. Excessive Impact yang biasanya terjadi pada waktu tertentu saja seperti benturan roda pendaratan pesawat dengan landasan pacu yang dapat berakibat fatal jika getaran yang dihasilkan tidak dapat dikontrol dengan baik. Salah satu metoda untuk mereduksi getaran yang diakibatkan dari (Excessive Impact) disebut sebagai PSMEID (Pre-Straining Momentum Exchange Impact Dumper), dimana dalam hal ini memanfaat momentum dari sebuah masa yang ditempatkan pada masa utama yang arah gayanya berlawanan dengan gaya yang dihasilkan oleh benturan. Pada penelitian sebelumnya system PSMEID diaktifkan sesaat setelah terjadinya benturan, karena tidak adanya mekanisme sensor untuk mendeteksi vibbrasi dan pergerakan benda yang terjadi. Maka dalam hal ini, penelitian ini mencoba merancang sistem sensor yang dapat mendeteksi pergerakan benda sebelum terjadinyanya Excessive impact. Dengan mengetahui posisi dan kondisi benda sesaat sebelum terjadi benturan maka dapat diprediksi waktu benturan sehingga waktu pelepasan massa dengan dorongan pegas yang sudah diregangkan (pre-straining) dengan arah yang berlawanan dari arah benturan memberikan hasil yang lebih optimal untuk mereduksi getaran dari benturan yang terjadi. Penelitian ini merancang system multinsensor yang terdiri dari sensor vibrasi, sensor percepatan dan sensor jarak yang bekerja sedekian rupa sehingga waktu aktifasi PSMEID mendekati/sama dengan waktu terjadinya benturan awal sehingga momentum dan percepatan dapat direduksi. Pada pengujian awal system sensor ini hanya melibatkan sensor vibrasi saja, dimana PSMEID mampu diaktifkan 32 ms.Kata Kunci : Excessive Impact, PSMEID
Web-based Monitoring System for Power Electronics Devices on Off-grid Solar Power Generator Amirul Luthfi; Eka Putra Waldi; Darmawan Darmawan; Baharudin Baharudin; Budi Sunaryo
JURNAL NASIONAL TEKNIK ELEKTRO Vol 10, No 1: March 2021
Publisher : Jurusan Teknik Elektro Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (310.639 KB) | DOI: 10.25077/jnte.v10n1.851.2021

Abstract

Power electronic devices are the main component of the solar power generation system. This study proposes a web-based monitoring system which presents power electronic performance parameter in a real-time across an internet connection. The investigation takes ACS712 and PZEM-004T for the power converter performance measuring and Arduino Mega 2560 with an ethernet shield for data acquisition and transmission. This paper describes the schematic design of the hardware and also explains the software work-flow and structure. The test and calibration on the sensor's voltage and current to standard digital multi-meter Tektronix DMM4050 show the sensor able to accurately read the converter performance parameter and meet the standard IEC-61724. The functionality test on the web-based information system indicates the designed user interface to present the power electronic performance parameter of the solar power generator.Keywords: Monitoring System, Power Electronics and Solar Power
The Properties of Humic Acids Extracted from Four Sources of Organic Matters and Their Ability to Bind Fe2+ at New Established Rice Field . Herviyanti; Teguh Budi Prasetyo; Fachri Ahmad; . Darmawan
JOURNAL OF TROPICAL SOILS Vol 15, No 3: September 2010
Publisher : UNIVERSITY OF LAMPUNG

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5400/jts.2010.v15i3.237-244

Abstract

The Properties of Humic Acids Extracted from Four Sources of Organic Matters and Their Ability to Bind Fe2+ at New Established Rice Field (Herviyanti, TB Prasetyo, F Ahmad and Darmawan):  In order to identify the properties of humic acid extracted from four kinds of organic matters (a peat soil, a stable manure, a compost of rice straw and a municipal waste)  and their potentiality to bind Fe2+  at new established rice field, a series of experiment was done in Soil Laboratory Faculty of Agriculture, Andalas University Padang. First step was characterization of functional groups and other chemical properties of humic acids, and their reaction with Fe2+. The second step was to examine the ability of humic acids to bind Fe2+ solution at new established rice field by conducting incubation experiments.  The experiment used  a completely randomized design with three replications.  The 450 ppm Fe solution was treated with 0, 50, 100, 150, 200, 250, 300, 350, 400, and 450 ppm humic acids and incubated for 24 hours.  While top soil samples taken from Sitiung, West Sumatera were treated with 0,100, 200, 300, and 400 ppm humic acids, flooded with deionized water, and incubated for 6 weeks.  The result showed that   the functional group and other chemical characteristic of humic acid from rice straw compost and peat soil were better than those of manure and municipal waste compost. Functional group of both humic acids was dominated by COO-. High reactivity of the humic acid had been found when humic acids were added to Fe solution with ratio 1 : 1. Use of humic acid extracted from peat soil with the levels from 0 to 100, 200, 300, and 400 ppm decreased the Fe2+ concentration from 1.361 ppm to  910, 860, 831, and 776 ppm, respectively at new established rice field.  While the use of humic acid extracted from  rice straw compost with the same levels as above decreased the Fe2+ concentration  from 1361 to 770, 701, 612, and 600 ppm, respectively, after four weeks of flooding.
Improving Soil Quality by Using Oil Palm Solid Waste Biochar Darmawan Darmawan; Sari Handani; Ikhsanul Adli
AGRITROPICA : Journal of Agricultural Sciences Vol 4, No 1 (2021)
Publisher : Badan Penerbitan Fakultas Pertanian (BPFP)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31186/j.agritropica.4.1.20-29

Abstract

Solid waste and land degradation are two main problem faced by oil palm plantation in mineral soils. In order to get rid of these difficulties, a field experiment has conducted at re-planting stage of oil palm in PT. Tidar Kerinci Agung plantation. The objective of this study is to examine the potentiality of biochar made from empty bunch of oil palm on soil quality. Fifteen plots of 100 square meters were applied with the dose of 0.0, 2.5, 5.0, 7.5 and 10.0 Mg/ha biochar, respectively. The results show the treatment increase soil organic matter, total pore space, water holding capacity and cation exchange capacity. On the other hand, soil bulk density found decrease significantly along with the treatment. These results indicated that application of biochar might be a better choice for sustainable oil palm plantation in mineral soil.
Co-Authors . Adrinal . Junaidi Agustian Agustian Amirul Luthfi, Amirul Baharuddin Abbas, Baharuddin Baharudin Baharudin Budi Sunaryo Eka Putra Waldi Erick Wahyudi Fachri Ahmad Hasnelly Hasnelly Herviyanti Herviyanti Ikhsanul Adli Lovely Son, Lovely Pharmayeni Pharmayeni Pharmayeni Pharmayeni Pharmayeni, Pharmayeni Sari Handani Silvia Herlena Sunaryo, Budi Syafrimen Yasin Teguh Budi Prasetyo Teguh Imanto Tsugiyuki Masunaga Yayan Syafriyatno