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Rekayasa
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  This is an Open Access Journal Open Access journal
ISSN (Print) 0216-9495 - ISSN (Online) 2502-5325
Published by Trunojoyo University Homepage  [5 journals]
  • Studi Gasifikasi Pengembangan Tongkol Jagung dengan Jerami Padi
           Menggunakan Reaktor Downdraft Dengan Dua Masukan Udara Tekan

    • Authors: Ibnu Irawan, Achmad Kusairi Samlawi, Hairil Budiarto
      Pages: 1 - 7
      Abstract: The production of corn and rice produced by farmers in East Java has the potential to cause agricultural waste, therefore corn cobs are waste that requires special processing in order to be used optimally. Agricultural waste corn cobs and rice straw can be converted into gas fuel (Syngas). The purpose of this study was to determine the performance of gasification seen from the temperature distribution and composition of combustible gases such as CO, H2 and CH4. The downdraft gasifier type is used and applies the AR and E.R ratio to the temperature. For the pyrolysis and oxidation regions, the intake air varies (ARpir-oxi) 80%; 70%; and 0% at 14.5 air intake; 19.3; and 24.1 Nm3/hour from E.R 0.3, 0.4, and 0.5. Air intake in the adjust area using a valve. Temperature measurement using the type K thermocouple. The results show that the maximum temperature using ARpir-oks = 80%, the drying zone temperature is 187°C, the pyrolysis zone is 488°C, the oxidation zone is 895°C and the reduction zone is 585°C. Meanwhile, the highest production of CO gas is 20.50% and H2 gas is 14.55% using an ER of 0.4. Meanwhile, CH4 decreased for all ER values using ARpir-oks = 80%.
      PubDate: 2022-04-10
      DOI: 10.21107/rekayasa.v15i1.12895
      Issue No: Vol. 15, No. 1 (2022)
       
  • Rancang Bangun Drone Solar Cell untuk Pengintaian dalam Mendukung Operasi
           Keamanan Laut

    • Authors: Endin Tri Hartanto, Hari Sulistyo, Anang Prasetiya Adi
      Pages: 8 - 14
      Abstract: The development of defense equipment and military technology in the TNI-AL is carried out in order to support the strengthening of the National Defense Strategic Industry (Instranas). Several steps have been taken in the development of defense equipment and military technology in the TNI-AL, namely by carrying out research and development of defense equipment. One of them is conducting research on unmanned aerial vehicles (UAV). The use and development of unmanned aircraft was initially carried out by the military to carry out military and intelligence operations. To carry out reconnaissance functions to support maritime security operations, requiring long endurance, a Solar Cell Drone is designed by utilizing solar energy. Based on the results of the design and testing that have been carried out, the drone is able to fly as long as it gets a supply of solar energy, which is throughout the day with the main load on the propulsion system. The thrust value obtained is 1266.8 watts or the equivalent of 3,998 kg of thrust which is able to fly a drone with a weight of 6.7 kg. The control system developed uses the Pixhawk 4 flight controller and remote control, the data communication system uses Telemetry NRF24L01 2.4 GHz. The results of this design and test can be a pioneer in developing Solar Cell Drones for the independence of the Indonesian Navy's defense equipment in the future.
      PubDate: 2022-04-10
      DOI: 10.21107/rekayasa.v15i1.14101
      Issue No: Vol. 15, No. 1 (2022)
       
  • Studi Eksperimen Biomassa Padat Sebagai Bahan Bakar Alternatif Menggunakan
           Campuran Limbah Pertanian

    • Authors: Rullie Annisa, Sri Wahyuni, Ibnu Irawan, Sayidil Anam
      Pages: 15 - 20
      Abstract: Biomass is one of the agricultural wastes that can be used as a substitute for alternative fuels. The biomass needs to be converted into briquettes first, so that it becomes an environmentally friendly fuel. Corn cobs and rice straw are the most common types of agricultural products found in East Java, therefore the potential for alternative fuels that will be obtained will also be higher. This research aims to determine the characteristics of solid fuels (briquettes) including: calorific value of briquettes, water content of briquettes, ash content of briquettes and drop test on briquettes using a mixture of corn cobs and rice straw. The variation of the mixture between corn cobs and rice straw is 1 kg, where 1 kg of corn cobs and straw using a mixture ratio of 90%:10%, 80%:20%, 70%:30% and 60%:40% using starch adhesive of 0.001 kg. In addition, it uses two pressure variations, namely: A = 2500 kPa and B = 5000 kPa which are used in briquettes. The results of the research on the characteristics of briquettes such as: The highest calorific value using a mixture of 90% corn cobs and 10% rice straw was obtain at 5546.74 cal/gram. The most optimal moisture content using a suppression load of 5000 kPa using a mixture of 90% corn cobs and 10% rice straw obtained a value of 11.30%. The optimal ash content produced also uses a suppression load of 5000 kPa by using a mixture of 90% corn cobs and 10% rice straw to obtain a value of 20.58%. While the drop test on briquettes using a pressing load of 5000 kPa by using a mixture of 60% corn cobs and 40% rice straw obtained a value of 11.10%, a large reduction in particle size when applied from a height.
      PubDate: 2022-04-10
      DOI: 10.21107/rekayasa.v15i1.12905
      Issue No: Vol. 15, No. 1 (2022)
       
  • Aktivitas Antioksidan dan Antibakteri Ekstrak Daun Kersen (Muntingia
           Calabura L) dengan Metode Microwave Assisted Extraction

    • Authors: Siti Mutammimah, Supriyanto Supriyanto, Mohammad Fuad Fauzul Mu’tamar
      Pages: 21 - 28
      Abstract: Kersen (Mutingia calabura) is a wild plant that is not cultivated and not many people know its benefits. So far kersen plants are only used as a shade even though the plant has the potential as an antioxidant and antibacterial. The purpose of this study is to find out the antioxidant and antibakeri activity of kersen leaf extract. The method used for extraction is Microwave Assited Extraction (MAE) with variations in temperature and extraction time. Analysis of antioxidant activity uses the DPPH method by calculating IC50 values while for analysis of antioxidant anctivity using the bland zone method. The results showed that the temperature and time of extraction affect antioxidant and antibacterial activity. The best treatment is obtained from low temperature treatment and extraction time for 7 minutes with IC50 and bland zone values of 44.21 ppm and 11.05 mm respectively.
      PubDate: 2022-04-10
      DOI: 10.21107/rekayasa.v15i1.13229
      Issue No: Vol. 15, No. 1 (2022)
       
  • Efisiensi dan Fouling Factor Sealtube Heat Exchanger Pada Proses
           Pendinginan Refined Bleached Deodorized Palm Oil

    • Authors: Jabosar Ronggur Hamonangan Panjaitan, Nurhasanah Nurhasanah, Laela Febby Atikasari, Ponilawati Ponilawati
      Pages: 29 - 35
      Abstract: Refined Bleached Deodorized Palm Oil (RBDPO) is a product of the crude palm oil (CPO) refining process. RBDPO is one of Indonesia's strategic commodities for low price cooking oil production. The cooking oil processing uses a heat transfer device such as heat exchanger. Heat exchanger sealtube 881X is a tool that used in the heat recovery unit at PT. Tunas Baru Lampung, Tbk refinery plant. Heat exchanger sealtube 881X used to cool refined bleached deodorized palm oil (RBDPO) to 95 – 105oC from the deodorization process by utilizing cooling water. In this research, the efficiency and fouling factor of the heat exchanger sealtube 881X were calculated at PT. Tunas Baru Lampung, Tbk refinery plant. Based on the results, it can be seen that the actual efficiency of Heat exchanger sealtube 881X was between 71-87%. Changes in the value of fouling factor affect the thermal efficiency of the heat exchanger sealtube 881X which from the calculation results, the highest fouling factor value was 0.0017.
      PubDate: 2022-04-10
      DOI: 10.21107/rekayasa.v15i1.13247
      Issue No: Vol. 15, No. 1 (2022)
       
  • Model Gelombang di sekitar Hexagonal Artificial Reef sebagai Submerged
           Breakwater Menggunakan DUALSPHYSICS

    • Authors: Haryo Dwito Armono, Adelbert Manurung, Sujantoko Sujantoko
      Pages: 36 - 45
      Abstract: The functions and uses of artificial reef have evolved from a method of coral reefs restoration to a coastal protection system. Artificial reef can reduce the hydraulic load on the coast to the level required to maintain shoreline balance. Various materials and shape of artificial reefs have been introduced. This paper discussed the wave transmission over hexagonal-shaped artificial reef with 6 holes on each side. The study was conducted using the Smoothed Particle Hydrodynamic (SPH) method integrated in DualSPHysics software to see the effect of gaps between structures with a predetermined configuration to the value of the transmission coefficient (Kt). It was found that the configuration with no gap was able to absorb waves better than the configuration with a gap of 0.15 m and 0.112 m based on the Kt value obtained. In terms of hydrodynamics, it was found that: (1) The increment of the wave steepness, the smaller the Kt value obtained, (2) The larger the wave height, the smaller the Kt value at 0.1 m freeboard depth, while on the freeboard with a depth of 0.2 m and 0.3 m, it was found that the greater the wave height, the greater the Kt value, (3) the increment of the wave period, the Kt were higher, and also (4) the higher the freeboard, the higher the Kt.
      PubDate: 2022-04-10
      DOI: 10.21107/rekayasa.v15i1.13484
      Issue No: Vol. 15, No. 1 (2022)
       
  • Pengaruh Kualitas Layanan Terhadap Kepuasan Pelanggan Perusahaan Daerah
           Air Minum (PDAM) Sumber Pocong Kabupaten Bangkalan

    • Authors: M. Arif Prabowo, Raden Faridz, Burhan Burhan
      Pages: 46 - 52
      Abstract: Clean water is a vital community need that needs special attention. The government needs to provide it adequately as a form of the mandate of the 1945 Constitution. Perusahaan Daerah Air Minum (PDAM), as a representation of the government, becomes an institution that takes on a role in meeting the needs of clean water. The increasing demand for clean water with a rising population needs to be balanced with good service. This research uses a case study in PDAM Sumber Pocong Bangkalan. PDAM Sumber Pocong serves various community needs, including registration, checking water bills, to payment. The assessment of service quality at PDAM Sumber Pocong is expected to be an input to improve the company's performance in the context of service. Customer satisfaction is a measure of service quality performance. This study aims to measure service quality and customer satisfaction of PDAM Sumber Pocong Bangkalan clean water and determine the effect of service quality and customer satisfaction. Three indicators of service quality (reliability, assurance, and facilities) and four customer satisfaction indicators (product quality, price or cost, service, and emotion) proved to be appropriate and relevant measures. Meanwhile, from the path analysis test, the service quality variable has a significant effect on the customer satisfaction variable. 
      PubDate: 2022-04-10
      DOI: 10.21107/rekayasa.v15i1.13539
      Issue No: Vol. 15, No. 1 (2022)
       
  • Unjuk Kerja Performa Turbin Arus Laut Sumbu Vertikal Pada Berbagai Bentuk
           Sudu Unik

    • Authors: Rizki Mendung Ariefianto, Rini Nur Hasanah, Wijono Wijono
      Pages: 53 - 63
      Abstract: Efficiency and self-starting capability performances are the main problems in vertical axis turbines. By purposing improves its performance, vertical axis turbines have been developed with various models. One of the developments of this model is to design the turbine blades into unique shapes. This research aims to determine the performance of some unique blade vertical axis turbines conditioned on the same parameters, especially if applied in a marine environment. Turbines with helical blade (HB), eggbeater-shaped blade (ESB), diamond-shaped blade (DSB), Y-shaped blade (YSB), and arrow-shaped blade (ASB) were investigated based on efficiency and self-starting capability using QBlade software. Good performance symmetrical foils such as NACA 634021 are also applied to each turbine. The simulation results show that from the aspect of efficiency performance, turbine ASB > HB > ESB > DSB > YSB. Meanwhile, in the aspect of self-starting capability performance, the sequence is similar to efficiency performance, based on the two approaches applied. The highest efficiency achieved by the ASB turbine is 0.391 at the lowest tip speed ratio of λ = 4. The ASB turbine also achieves the best self-starting performance, which has a minimum static torque coefficient of 0.00155 and can produce the required power at the lowest marine current speed of 0.806 m/s. This performance brings the ASB turbine to produce a rated power of 52.52 kW, or more than twice the power production of the lowest efficiency turbine and has an average power gain of 3.75 kW per 0.2 m/s.
      PubDate: 2022-04-10
      DOI: 10.21107/rekayasa.v15i1.13572
      Issue No: Vol. 15, No. 1 (2022)
       
  • Analisis Emisi CH4 dan Potensi Energi dari Tempat Pembuangan Akhir (TPA)
           Muara Fajar 2 Kota Pekanbaru

    • Authors: Aryo Sasmita, Jecky Asmura, Betharia Nurmaida
      Pages: 64 - 70
      Abstract: The city of Pekanbaru as an economic center and a destination for urbanization in Riau province has also experienced an increase in population. This is the cause of the increase in the amount of waste that enters the Muara Fajar 2 TPA Pekanbaru City. Solid waste that is stockpiled in the TPA undergoes a degradation process resulting in greenhouse gases in the form of CH4 which contribute to global warming, but have the potential to be utilized as alternative energy. The purpose of this study was to calculate CH4 emissions from landfilling activities at TPA 2 Muara Fajar Pekanbaru City and the potential energy produced. The method for calculating landfill gas emissions uses the IPCC 2019 method. The amount of waste that goes to the TPA in 2011-2020 is obtained from the Pekanbaru City Environment and Forestry Office. The highest estimated values of CH4 gas emissions resulting from landfilling activities at the Muara Fajar 2 TPA Pekanbaru City occurred in 2049 with CH4 emissions of 34,847 Mg/year and CH4 volume of 48,560,479 m3/year. The daily electricity generated is 52,052.84 kWh which can meet the electricity needs of 9,362 households in Pekanbaru City.
      PubDate: 2022-04-10
      DOI: 10.21107/rekayasa.v15i1.13284
      Issue No: Vol. 15, No. 1 (2022)
       
  • Model Aplikasi Structural Equation Modelling (SEM) Untuk Kebijakan
           Profesionalisme Perwira TNI Angkatan Laut

    • Authors: Sukmo Hadi Nugroho, Okol Sri Suharyo, Aang Chrys
      Pages: 71 - 78
      Abstract: The development of the Indonesian Navy's strength is carried out through a strategic planning process manifested in four activity programs, namely (1) the Marine Readiness Support Program; (2) Modernization Program for Alutsista and Non-Alutsista as well as the Development of Facilities and Infrastructure for the National Defense for Marine; (3) Professionalism Enhancement Program for Marine Personnel; (4) Marine Management and Operation Implementation Program. The Indonesian Navy realizes that the main strength of all force-building programs lies in the quality of the human resources (HR) possessed by the Indonesian Navy. However, the existing reality reveals various kinds of problems and obstacles that hinder the process of improving the quality of existing human resources. For this reason, the Indonesian Navy seeks to improve the pattern of training for personnel by issuing policies that spur the performance of the personnel development system within the Indonesian Navy. From these problems, a research or modeling is needed that can represent how the influence of the Indonesian Naval Personnel Development Pattern and Indonesian Navy Policy on Officer Professionalism to create superior navy personnel in line with the Indonesian Navy development program towards the World Maritime Axis. The method used in this research is Structural Equation Modeling (SEM). There are 27 indicators consisting of 5 indicators of Angkatan Laut policy variables, 13 indicators of personnel development variables and 9 indicators of professionalism. The results showed that there was a significant direct influence between the Angkatan Laut policy variables on personnel development, personnel development on professionalism and Angkatan Laut policies on professionalism. In addition, there is an indirect influence between Angkatan Laut policies on professionalism through personnel development as a mediating variable.
      PubDate: 2022-04-10
      DOI: 10.21107/rekayasa.v15i1.13945
      Issue No: Vol. 15, No. 1 (2022)
       
  • Inventory of Pests and Diseases Intensity on 10 Bambara Groundnut (Vigna
           subterranea (L.) Verdc.) Lines in The Dryland of Madura, Indonesia, during
           The Dry Season

    • Authors: Siti Fatimah, Siti Muafalah, Nurholis Nurholis, Achmad Djunaedy
      Pages: 79 - 86
      Abstract: Landraces breeding scheme of bambara groundnut from various regions of Indonesia since 2012 provides several potential lines which are uniform, high yielding and drought-tolerant. Evaluation of resistance to pests and diseases is aimed to select potential lines which are resistant to pests and diseases and potential for development in Madura dry land during the dry season. The present study used descriptive method through field observation technique on 10 selected potential lines of Bambara groundnut. The results showed that there were 5 (five) types of pests and 4 types of diseases found in bambara groundnut crops planted during the dry season in Bangkalan Regency of Madura. The pests attacking more than 25% per plot were aphids, ladybugs and grasshoppers. A symptom of pathogen attacking more than 25% per plot were Bean common mosaic virus and soybean common mosaic virus. The GSG 1.1.1 potential line had the lowest pest attack and the BBL 2.1.1 potential line had the lowest disease incidence.
      PubDate: 2022-04-10
      DOI: 10.21107/rekayasa.v15i1.13988
      Issue No: Vol. 15, No. 1 (2022)
       
  • Rancangan Strategi Menangani Ancaman Perang Hybrida Melalui Patroli
           Maritim di Kawasan Laut China Selatan

    • Authors: Hadi Syafruddin, Judijanto Judijanto
      Pages: 87 - 91
      Abstract: The ever-changing dynamics in the South China Sea are making international relations even hotter, especially Western countries that feel threatened by China's claims to the South China Sea region with its Nine Dash Line. The South China Sea claimed by China is the North Natuna Sea which is included in the territory of the Republic of Indonesia. Lately the disputed countries use a new strategy of hybrid war that has been waged by the Chinese state in making a coercion by demonstrating capability in terms of strength. This problem makes Indonesia whose territory is affected in the North Natuna Sea must quickly anticipate in response to hybrid warfare by firmly declaring itself as a non-claimant states participating in the arena of dispute in an effort to claimant-states (state parties) in seizing rights in the South China Sea creating an unconventional war called hybrid warfare. One strategy using the SWOT method can conclude that in a prominent variable with opportunities where variables of cooperation with foreign countries greatly help realize the game, security and stability of the region in the Natuna Sea. The strategy used by increasing the variable strength (Strong) and opportunity (Opportunity) so as to increase the security and stability of the NKRI region in the Natuna Sea.
      PubDate: 2022-04-10
      DOI: 10.21107/rekayasa.v15i1.14123
      Issue No: Vol. 15, No. 1 (2022)
       
  • Pendugaan Umur Simpan Garam Mandi (Bath Salt) Aroma Serreh Menggunakan
           Metode Accelerated Shelf Life Testing (ASLT)

    • Authors: Meilinda Cendana Putri, Iffan Maflahah, Supriyanto Supriyanto, Dian Farida Asfan
      Pages: 92 - 99
      Abstract: Salt contains compounds of magnesium chloride, magnesium sulfate, magnesium bromide, and other trace compounds. In general, salt is divided into consumption salt and industrial salt. Bath salt is a salt product that dissolves in water and reduces wrinkles on the hands. The constituent components of bath salts are Epsom salt, sodium bicarbonate, SLES, cornstarch, olive oil, citronella oil, and alcohol, the packaging used is glass packaging. Shelf life is done by accelerating the degradation reaction using high temperature storage and simulating the data obtained. The purpose of this study was to determine the quality characteristics of bath salts before and after storage and to determine the shelf life of bath salts with the aroma of lemongrass. This research was conducted at the Quality Analysis Lab of the Agricultural Industrial Technology Study Program, Faculty of Agriculture, Trunojoyo University, Madura from September to October 2021. Shelf life was estimated using the Arrhenius method. Based on research at a temperature of 28, the shelf life of bath salts is 180.86 or 6 months 1 day, while at a temperature of 35 is 85.85 or 2 months 26 days. It is proven by the value of the shelf life which is getting shorter with the higher the storage temperature. An increase in temperature causes a greater rate of reaction
      PubDate: 2022-04-15
      DOI: 10.21107/rekayasa.v15i1.13855
      Issue No: Vol. 15, No. 1 (2022)
       
  • Review Optimalisasi Penggunaan Produk Industri Strategis Nasional untuk
           Mendukung Kesiapan Alutsista TNI AL

    • Authors: Umar Winarno, Desi Prianti, Mohammad Fadli, Moeljadi Moeljadi
      Pages: 100 - 106
      Abstract: The implementation of the main tasks of the Indonesian Navy must be supported by the strength of the defense doctrine, human resources, and the main tools of the Indonesian Navy's reliable weapon system (alutsista). Observing the current condition of the Indonesian Navy, it is still far from the conditions that are expected to be able to carry out its main tasks, especially with the state of readiness of the defense equipment system. The current condition of the TNI AL's strength when compared to the strength of neighboring countries in the ASEAN region is still lagging behind. To be able to improve the readiness of the Indonesian Navy's defense equipment, including optimizing the use of national strategic industrial products to support the readiness of the Indonesian Navy's defense equipment, which has a fairly reliable ability to produce, assist maintenance and repair of defense equipment. The purpose of this paper is to find out and analyze the implementation of the use of national strategic industrial products, the implications for the support of the Indonesian Navy's defense equipment and how the solutions are to support the readiness of the Indonesian Navy's defense equipment in order to increase national security. This writing uses a normative juridical approach through assessing the capabilities of national strategic industries, fulfilling the needs of the Navy's defense equipment, human resources capabilities in technology transfer, budget support and optimizing the use of national strategic industrial products to increase national resilience. The conclusion is that the use of national strategic industrial products has a close relationship in terms of supporting the readiness of the Navy's defense equipment and increasing national security.
      PubDate: 2022-04-22
      DOI: 10.21107/rekayasa.v15i1.11576
      Issue No: Vol. 15, No. 1 (2022)
       
  • Analysis of The Ratio Catalys Promoters BaO/CaO to Methyl Ester Content
           and Yield in Biodiesel Using Electrocatalytic Reactor

    • Authors: Elli Prastyo, Puji Astuti Ibrahim, Dian Farkhatus Solikha
      Pages: 107 - 113
      Abstract: The efficiency of biodiesel production from vegetable oils needs to be developed. The process of transesterification using heterogeneous catalysts has been widely studied to replace the role of homogeneous catalysts. The use of BaO promoters into metal oxides increases the activity of heterogeneous catalysts in transesterification reactions. This study was conducted to provide information about the effect of BaO concentrations that are filtered into calcium oxide (CaO) on the transesterification reaction of tofu pulp oil into methyl ester using electrocatalytic methods. The study was conducted at room temperature with a voltage of 18.5 Volts and a reaction time of 120 minutes. Methanol ratio: tofu oil is used at 10:1 with Tetra Hydro Furan (THF) as a co-solvent. The electrocatalytic process is carried out using graphite electrodes. The research variables are the concentration of BaO promoters used at 2%, 4%, and 8%. The parameter of the test is methyl ester content obtained from the results of transesterification reactions with chromatography gas analysis (GC-MS). In this study, the BaO/CaO catalyst was impregnated by wet method and calcined at 450oC for 180 minutes. From the experiments conducted the highest methyl ester yield was obtained in bao / cao catalyst 2% with a yield of 99.99% and biodiesel yield of 94%.
      PubDate: 2022-04-29
      DOI: 10.21107/rekayasa.v15i1.13761
      Issue No: Vol. 15, No. 1 (2022)
       
 
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