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Leni Mardiana, Nunik Cokrowati, Alis Mukhlis
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 151-157; https://doi.org/10.21107/rekayasa.v15i2.10137

Abstract:
White snapper (Lates calcarifer) is a type of seawater fish that is in great demand by the public. This study aims to determine the 48-hour LC50 value and the effect of using betel leaf extract on the health status of white snapper. This research was conducted in July 2020 which took place at the Sekotong Coastal Aquaculture Development Center (BPBPP), West Lombok Regency, West Nusa Tenggara. This research was conducted using experimental methods. This study used 5 treatments and three replications, to obtain 15 experimental units with doses of 0 ppm, 80 ppm, 90 ppm, 100 ppm and 200 ppm. Data analysis was performed using a linear regression test, namely probit analysis by testing the mortality of tested animals and calculated through statistical data using Microsoft Excel. The higher the betel leaf extract concentration, the higher the number of white snapper seed deaths. This happens because the betel leaf extract contains active antimicrobial compounds, but at high concentrations, it can poison the white snapper seeds. For further research, it is recommended to test the toxicity of betel leaf extract on the mortality of white snapper with variations in water quality. 
Didik Budiyanto, Sri Oetami Madyowati, Achmad Kusyairi
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 137-142; https://doi.org/10.21107/rekayasa.v15i2.14135

Abstract:
Milkfish is one of the fishery commodities that are in great demand by the Indonesian people, where the obstacle to production decline is disease. Therefore, to prevent disease and treat diseases that attack fish, farmers use the antibiotic Chloramphenicol. However, the use of high doses of antibiotics will cause resistance to pathogenic bacteria and the residue left in the fish's body will have a negative impact on human health who consume them such as allergies, toxicity and even cause death in anemia sufferers which can progress to leukemia. This study aims to determine the length of downtime of the antibiotic Chloramphenicol on changes in residual levels in milkfish (Chanos chanos) aged 30 days decreased to a safe limit for consumption. Residual content test using ELISA at 450 nm wave. Based on the results of the study, milkfish fed with a mixture of chloramphenicol antibiotics at a dose of 1 ppm resulted in the highest residual value of 4.6375 ppb in the first week and a decrease in residue to 0.2363 ppb for 5 weeks. The stopping time of chloramphenicol antibiotics on changes in residual levels in milkfish (Chanos chanos) aged 30 days in treatment F (Milkfish fed with a mixture of chloramphenicol at a dose of 1g/kg of feed for a week, then fed without a mixture of chloramphenicol for 5 weeks) resulted in a safe limit for consumption.
Riyan Latifahul Hasanah, Yan Rianto, Dwiza Riana
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 204-214; https://doi.org/10.21107/rekayasa.v15i2.14580

Abstract:
Acne vulgaris or acne is a common inflammatory pilosebaceous condition that affects up to 90% of teenagers, begins during adolescent years, and often persists into adulthood. Acne vulgaris, especially on the face, has a major impact on the emotional, social and psychological health of patients. In treating acne, it is necessary to identify the exact type of acne. The manual method is considered less effective, so it is proposed an automatic method using a computer, which uses image processing techniques. This research was conducted to identify the types of acne on facial acne images. The methods used are K-Means Clustering for segmentation, Gray Level Co-occurrence Matrix (GLCM) for feature extraction, and Extreme Learning Machine (ELM) for classification. The dataset is 100 images and consists of 3 classes, namely Nodules, Papules and Pustules. Testing is done in two stages, namely testing 2 classes (Nodules and Papules), followed by testing 3 classes (Nodules, Papules and Pustules). Testing of 2 classes produces the highest accuracy of 95,24% and testing of 3 classes produces the highest accuracy of 80%.
Halimatus Sa'Diyah, Suhartono Suhartono
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 247-252; https://doi.org/10.21107/rekayasa.v15i2.15130

Abstract:
Characterization is the first step in breeding to obtain information about a plant's character. This study aims to determine the character of the hybrid melon candidate. The research was carried out in the experimental garden of the Agrotechnology Study Program, Trunojoyo University, Madura, from September to December 2021.The research used a randomized block design with treatment using six hybrid melon candidates (G1, G2, G3, G4, G5, and G6) and two comparison varieties (Envy and Action 434) with three replications. The results showed that Candidate G2 had higher values of fruit diameter, flesh thickness, number of seeds, and fruit weight than the two comparison varieties. The highest sugar content value is found in candidate G4, which is 13.80%. Heritability values in the broad sense of quantitative characters ranged from 0.62-0.98, and there were correlations between characters (positive and negative) between the observed characters.
R Dwiki Rachwanto, Saidah Saidah, Amirullah Amirullah
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 182-191; https://doi.org/10.21107/rekayasa.v15i2.13454

Abstract:
Inverters with square waves and sinusoidal output signal waves have different efficiency values. The difference is very visible, especially when the inverter is used to drive an electric device that uses a motor. In a sinusoidal wave type inverter, electricity consumption will be more efficient than the use of a square wave type inverter. This study aims to determine the efficiency value of the square wave and sinusoidal inverter wave output in supplying the load. Square wave and sinusoidal inverters require a controller, the controller uses an Arduino Uno which acts as an SPWM signal generator and a square wave signal is used to drive the MOSFET with push-pulls topology. Based on the results of the inverter test to determine the efficiency, it shows that the inverter with sinusoidal output is 96.40% better, while the inverter with square wave output is only 83.34%, this test is carried out using a 50W LED lamp load.
Muhammad Baharudin Fahmi, , , Harish Wirayuhanto
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 114-120; https://doi.org/10.21107/rekayasa.v15i2.14848

Abstract:
Generally, the purpose of artificial reefs is to rebuild naturally occurring coral reefs that have been destroyed. Without sacrificing the attractiveness of the protected beach, these manmade reefs functioned as new habitats for marine life and protected coasts by reducing wave energy. on the other side man-made artificial reefs can perform as submerged breakwaters, their ability to dampen incoming waves must be investigated. In this paper, the researchers present a new shape in the form of a hexagonal artificial reef. The wave attenuation performance index is calculated using the wave attenuation performance rating. The research focuses on the effect of structural height (h/d) on transmission wave value using a physical testing method on a scale of 1:10 at the wave flume of the Department of Marine Engineering, Sepuluh Nopember Institute of Technology, Surabaya. The test results indicate that the smallest transmission coefficient (KT) was produced on artificial reefs Configuration A-3 with the greatest submerged depth (h/d=0.75). The parameter results indicate that the greater the wave steepness (H/gT2) and the significantly larger the immersion depth (h/d), the better the wave reduction.
Yahya Prasetyo, Marthin Luther, Etwin Ramadhan, Jumino Jumino
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 275-282; https://doi.org/10.21107/rekayasa.v15i2.16420

Abstract:
Along with the development of naval technology, the roles, tasks and functions of the support of the Motorized Transport Battalion (Yon Angmor) have the complexity and dynamics of movement in supporting the implementation of Amphibious Operations, which are very important and have high traffic. In this study, conducted to identify and analyze organizational readiness, readiness in the field of Operations as an element of Satbanmin, and the readiness in the field of Logistics as an element of Satbanmin in the implementation of Amphibious Operations. The results of the measurement using SEM AMOS 23 software from the measurement model of the three variables of operational readiness, organizational readiness and logistical support readiness that affect administrative assistance support, that the operational readiness variable produces the highest value of 0.566. This means that the implementation of the operational readiness of the Yon Angmor in supporting administrative assistance in Amphibious operations can be carried out optimally and according to SOPs, despite having obstacles and problems in organizational readiness. So, to answer the existing problems, the Yon Angmor needs to plan the formation of an organization through organizational validation, as well as calculating risk management in supporting administrative assistance in the implementation of comprehensive amphibious.
Rahmawati Fitria, Henita Rahmayanti, Bagus Sumargo
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 121-128; https://doi.org/10.21107/rekayasa.v15i2.15057

Abstract:
An Ecological drainage becomes an application in this development project in the Kelapa Gading area. The drainage concept that is applied is a drainage system in which rainwater that falls on road surface runoff will flow directly into the water infiltration system and directly fill the ground surface water. Geologically, it can be seen that North Jakarta is an area with a fairly high ground water level (MAT), and has an average MAT elevation of 2 - 2.5 m. This study intends to determine the ability of this ecodrainage to reduce runoff/floods that often occur in areas with a fairly high MAL. What direct benefits can be felt in the use of ecodrainage in these flood-prone areas, thus making the basic reason for applying this ecodrainage. This study uses a dynamic systems approach. In the preparation of the dynamic system model, Powersim Studio Version 10 software will be assisted. The simulation results show that an increase in rainfall every year will provide an increasing flood potential. By using eco-drainage, it is felt that it is not optimal enough to reduce runoff in areas that have high MAT levels. However, this ecodrainage still provides broad sustainability benefits. The quantity of groundwater will slowly be filled up to the aquier layer through this ecodrainage. This step is considered to be able to help prevent the aquifer layer from being exposed and have an impact on the rate of land subsidence so that the potential for flooding will decrease.
Rahmat Alkadri, Basri Mustari, Agung Setiawan
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 199-203; https://doi.org/10.21107/rekayasa.v15i2.14155

Abstract:
The Indonesian Navy is a military force owned by the State of Indonesia.One of the main components of the Indonesian Navy is a warship (KRI).The role of the KRI in the implementation of the peak training of the jaya fleet is to carry out various ship formations which will later be used during operations.This study was conducted to describe the increase in the learning outcomes of Marine Corps AAL cadets on the use of the Bridge Simulator.The type of research used is Pre-experimental with One Group Pretest and Posttest Design.The research subjects were AAL cadets Level III and Level IV Marine Corps.The results of this study indicate the learning outcomes of cadets.Paired t-test data analysis using SPSS 25 for windows showed sig (2 tailed) 0.00 less than 0.05, which means H0 is rejected so that there is a significant increase in learning outcomes.The use of the Bridge Simulator can improve the learning outcomes of Marine Corps AAL cadets.
Eko Yulianto, Tunggul Puliwarna, Jumino Jumino
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 253-259; https://doi.org/10.21107/rekayasa.v15i2.14153

Abstract:
The Indonesian Navy (TNI AL) is required to have a persistently broad Maritime Domain Awareness (MDA). In meeting its MDA demands, apart from using the KRI Radar, the Indonesian Navy needs to be supported by other airborne surveillance sensors and sensing satellites in outer space. For airborne sensors, Puspenerbal has been equipped with a fleet of maritime patrol aircraft  (MPA) based on Casa NC 212-200 MPA and CN 235-220 MPA. However, all of these MPAs have a low detection capacity (<100 Km) and are not equipped with weapons to respond to threats on the surface or under the sea. For this reason, it is necessary to carry out research on the Long Range MPA requirement to support the tasks of the Navy with the aim of providing information and input to the Leaders in making decisions related to the plan to procure weapons and the strategic policies of the Navy to enforce defense and maintain security in the marine area of national jurisdiction. Indonesia This research will use the Analytical Hierarchy Process (AHP) method to determine the choice of maritime reconnaissance aircraft with predetermined criteria with alternative options, namely P-8A Poseidon, SAAB 6000 MPA, Kawasaki P-1, and ATR 72 MPA. The selected alternative was based on a combination of 3 criteria, namely P-8A Poseidon 58.3%, SAAB 6000 MPA 20.4%, Kawasaki P-1 14.4%, and ATR 72 MPA 6.8%. the result of the selection of the Tactical Reconnaissance Maritime Patrol Aircraft is that the P-8A Poseidon is the right alternative to choose. with an Inconsistency value of 0.06. This shows that the calculation of the alternative is still within the inconsistency threshold, which cannot be more than 0.1.
Ahmad Afandi, Dwi Soedianto, Edy Iwan Bangun
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 175-181; https://doi.org/10.21107/rekayasa.v15i2.14154

Abstract:
The Indonesian Air Force is the main combat tool in the use of force to defend the sovereignty and territorial integrity of the Unitary State of the Republic of Indonesia as a unit in order to achieve guarantees for the safety of the nation and state. Indonesia only relies on 33 F-16 AM, BM, C and D aircraft, which are more than 30 years old. Then 16 Sukhoi 27 and 30 aircraft with almost 20 years of age as the main fighter aircraft. The limited number of aircraft spare parts as well as the limited types and number of guided missiles also caused the combat readiness of the F16 and Sukhoi 27 and 30 aircraft to be not optimal. The F5 Tiger fighter has fallen out of service in recent years and there has been no replacement to date. Likewise, the Hawk 100/200 aircraft which are more than 25 years old. the obligation of the Ministry of Defense to plan the purchase of fighter aircraft that will operate until 2030 and 2040. This research will use the Analytical Hierarchy Process (AHP) method to determine the choice of Combat Aircraft with predetermined criteria with the alternative choice of Dassault Rafale fighter aircraft from France, the Su 35 Russian-made and US-made F-15 EX aircraft. The highest data processing results are Dassault Rafale 63.7%, Su 35 20.3% and F-15 EX 16%. The result of the Multirole Combat Aircraft selection is that the Dassaut Rafale is selected. with an Inconsistency value of 0.04. This shows that the alternative calculation is still within the inconsistency threshold, which is <0.1. With the election of Dassault Rafale, it is hoped that the Transfer of Technology with PT. Indonesian Aerospace in order to increase the capability of the Domestic Defense Industry, especially the Air Force. later PT DI will be directly involved in the Maintenance, Repair, and Overhaul (MRO) process, including the preparation of the supporting infrastructure
I Made Budi Wirawan, Syarif Mustika Harinurdi, Achmnad Faisol
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 241-246; https://doi.org/10.21107/rekayasa.v15i2.14334

Abstract:
Submarines of very strategic value in their procurement are directed to realize a deterrence strategy and a balancing strategy with state actors that have the potential to threaten the sovereignty of the Indonesian state. In addition to threats, the procurement of submarines also considers the geographical constellation of Indonesia. The first step in procurement is to make an analysis in terms of selecting alternative submarines, both analysis of information and identification of various important and interrelated requirements regarding data from alternative submarines that will be selected. In this condition, it can be solved by using fuzzy AHP approach. The results obtained from the Fuzzy AHP method are the order of priority for selecting alternative submarines, namely Scorpene Class (0.398), Changbogo Class (0.220), Reis Class (0.191) and Gotland Class (0.191). Where the results of the importance of the main criteria are sequentially starting from the Strategic Requirement (Strareq) criteria of 0.409, Operation Requirement (Opsreq) of 0.318 and Technical Requirement (Techreq) of 0.273.
, Hakam Muzakki, Hoomzah Nur Alisiyah, Raden Apriyanto
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 223-232; https://doi.org/10.21107/rekayasa.v15i2.15494

Abstract:
There are two important aspects of the implementation of this research, namely the technical aspect, which includes the production and analysis of the quality of liquid fertilizer products from fish farming wastewater, and the economic aspect, which includes an economic analysis on an industrial scale. Liquid fertilizer is made from fish farming wastewater obtained from Bangkalan Regency, East Java Province, Indonesia. The process of producing liquid fertilizer from fish farming wastewater includes various processes, from mixing to fermentation. The physical characteristics of liquid fertilizer from fish farming wastewater are in accordance with existing standards. Without the addition of nutrients, liquid fertilizer from fish farming wastewater has nitrogen (N) 1.33%, phosphorus (P) 0.44%, and potassium (K) 0.38%. Although the nutrient content of liquid fertilizer from fish farming wastewater is still below the standard of SNI 02-4958-2006, in industrial-scale production processes, adding nutrients is very necessary. In the economic analysis, all economic parameters are declared feasible and profitable, with an NPV value of Rp. 5,524,899,840, IRR 31,79%, PP 3.15 years and B/C ratio 3.1. This study shows a positive value on the technical and economic aspects. Finally, this research can be used as a reference by academics, government, and entrepreneurs in the technical and economic aspects of producing liquid fertilizer from fish farming wastewater.
Ferdita Syalsabila, Rudi Walujo Prastianto, Daniel Mohammad Rosyid
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 129-136; https://doi.org/10.21107/rekayasa.v15i2.15102

Abstract:
Accelerating marginal field development must consider the economic factor. While the structural strength must remain capable and robust when subjected to environmental loads. To meet the desired objective in design phase, optimization is used. With the rapid growth of computing technology, the optimization method is developed as more advanced and reduced iteration time. However, the structural evaluation of jacket structure is a complex problem. The usual process of structure evaluation is through finite element analysis, and it is still time-consuming. Thus, surrogate models can evaluate the structure, lowering computational time. This study optimizes the jacket structure to get an affordable and robust minimal jacket structure. Sizing optimization will be performed on the jacket's leg and bracing thickness. For single-objective optimization, weight structure is considered the objective function, and multi-objective optimization adds production cost as the second objective function. The surrogate model uses the radial basis function to predict the relation between design variables and ultimate limit strength. The functions generated from the surrogate model will act as behaviour constraints in the optimization process. For consideration, X-type and V-type bracing configurations are compared. Different results were obtained from the single objective and multi-objective optimization process.
Joan Ferdiyanto, I Made Wira Hadi Arsanta, Sadimin Sadimin
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 158-163; https://doi.org/10.21107/rekayasa.v15i2.14152

Abstract:
Indonesian Navy flights as an integral part of the SSAT have several functions, one of which is to provide rapid logistical support. Based on considerations of function and mobilization capabilities, medium-sized military transport aircraft are the main choice in providing rapid logistical support. The advantages of this function and mobility also make military transport aircraft capable of carrying out additional tasks assigned to their guiding squadron, namely the 600 Air Wing Squadron. The additional tasks are Search and Rescue (SAR), Air Medical Evacuation (EMU) and VIP Flights. Currently, there are 11 elements of the NC212-200 aircraft owned by Puspenerbal, with a description of 7 active elements, 4 disposal processes. In 2017, Puspenerbal received the Beechcraft King Air 350i light transport aircraft, but several operational requirements were not met to carry out the main function as an element of fast logistics support provider, so this element was prioritized to carry out additional functions such as VIP flights. The results of the analysis using the Analytic Hierarchy Process (AHP) method with the help of the Expert Choice 11 Application show the weight of the criteria for selecting medium military transport aircraft, namely Navigation and Communication Equipment 46.4%, Short Take-off and Landing (STOL) Ability 31.7 %, Transportability 15.3%, and Flying Ability 6.7% with an Inconsistency value of 0.07. This shows that the calculation of the correspondent is still within the inconsistency threshold, which cannot be more than 0.1. While the order of priority for the alternative types of medium military transport aircraft from high to low is the CN 295 type 80.5% and the Alenia C27J Spartan type 19.5%. Based on this value, it can be seen that the CN 295 Medium Military Transport Aircraft is the right alternative to be chosen.
Agung Hadi Tamari,
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 164-174; https://doi.org/10.21107/rekayasa.v15i2.14444

Abstract:
The performance of a photovoltaic (PV) generator is strongly influenced by the intensity of sunlight hitting the solar module. Thus it takes the position of the solar module which is always perpendicular to the direction of the sun's rays. To overcome this, it is necessary to design and implement a two-axis solar tracker system using a servo motor that is able to dynamically drive a PV generator following the direction of movement of sunlight supplied by an AC power source (PLN). The problem is that if the AC source is disturbed, the motor drive stops working so that the absorption of sunlight is not optimal. The research proposes the design and implementation of a two-axis solar tracker system based on Arduino Nano using a photodiode sensor and automatic transfer switch (ATS). ATS functions if there is a disturbance in the AC source, the system automatically transfers the load power supply to a DC source in the form of a battery or vice versa, so that the tool is still able to work. The photodiode sensor in the Arduino Nano circuit is used because it has better sensitivity to sunlight than the light-dependent resistor (LDR) sensor. The PV generator in this study uses the PV1 and PV2 modules.The results shows that the PV module using a two-axis tracker system with dynamic movement following the movement of the sun's position is able to produce a more significant and more stable average output voltage-than the system without using a tracker both on the static PV module position facing east and west respectively by 12.34% and 10.94%.The sensitivity of the photodiode sensor to sunlight also helps improve the performance of the proposed system so that the PV output voltage in the 09.00-15.00 WIB period, becomes larger and more stable than the system without a solar tracker.
Siti Rohmatin, Kaswan Badami, Gita Pawana
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 260-266; https://doi.org/10.21107/rekayasa.v15i2.15109

Abstract:
One of the obstacles to melon cultivation is the availability of seeds and the high price of melon seeds. This condition causes the need to assemble superior melon varieties with the expected characters. This study aims to form a pure line of melon with certain superior characteristics and can be proposed as a new high-yielding variety in the open-pollinated category. The research was conducted at the Experimental Garden of the Agrotechnology Study Program, Faculty of Agriculture, Trunojoyo University, Madura, from September-December 2022. This study used a randomized block design method. The treatments used were nine pure lines of melon (PK-669, D-162, PK-361, PK-165, PK-114, D-029, D-5089, PK-211, and comparison). Each treatment was repeated three times, and each experimental unit consisted of 12 plants. Research data were analyzed using analysis of variance (ANOVA) and HSD test α = 0.05. The selection advancement was analyzed by comparing character data for each generation. The research showed that the results of the characterization of ten melon lines S0-S4 generation on the characters of fruit length, fruit diameter, flesh thickness, and melon fruit weight showed a decreasing trend in each generation. The S4 generation (9.17 °brix) in the character of the average sugar content there was an increase that was not significantly different from the S3 generation (9.03 °brix), while the number of seeds in each generation had an average value that was not significantly different but occurred an increase in the number of seeds in the S3 (372) and S4 (381) generations. An increase in one generation of the population in the linear regression equation is estimated to reduce the character of fruit length by 0.50 cm, fruit diameter by 0.465 cm, flesh thickness by 0.140 cm, fruit weight by 0.199 Kg, sugar content by 0.752 °brix, and a number of seeds by 5.4.
Pamuharsi Pamuharsi, Untung Purnomo, Istin Marlena Dewi
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 267-274; https://doi.org/10.21107/rekayasa.v15i2.16212

Abstract:
According to the results of the brevet monitoring that has been carried out by the Department of Applied Psychology, the Subdiscipline of Applied Psychology on students of career NCO education and Private Private Career education, it is indicated that at this time the alumni of career NCO education and career Private Enlisted Officers lacked interest in attending education. This brevet can be seen from the number of soldiers who follow the brevet monitoring with the number of registrants when the opportunity is opened to take brevet education. This decline in interest occurred in all brevet education, and one of them was Taifib brevet education. Psychological aspects have a strong influence on interest, therefore researchers feel it is important to conduct research on the psychological aspects of the Marines Self Concept (X1) on interest in attending taifib brevet education and psychological aspects of emotion regulation (X2) on marine soldiers' interest in attending education taifib brevet (Y). The research method used in this study is a quantitative research method using the Classical Assumption Test. The results showed that Self Concept (X1) and emotion regulation (X2) simultaneously had no significant effect on the interest of marines in attending taifib brevet education (Y). attending taifib brevet education that self-concept and emotional regulation only affect 17% of marines' interest in attending taifib brevet education. Meanwhile, 83% of marines' interest in attending taifib brevet education is more influenced by other variables outside the study.
Muhammad Rifqi Hanif, Haryo Dwito Armono
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 192-198; https://doi.org/10.21107/rekayasa.v15i2.15246

Abstract:
In solving the problem of abrasion and also protecting marine ecosystems, it is necessary to come up with an idea, namely a wave energy retaining structure that is also capable of being a habitat for marine biota. Therefore, in this study, artificial coral reefs were tested which are considered capable to solve these problems, plus those which at the same time rehabilitate damaged coral reef ecosystems. The artificial reefs model in this test is a hexagonal type with one layer arrangement. To get the success value (KD) of artificial reefs, it is seen from the percentage of damage caused by the influence of height and wave period. Then the KD value was calculated using the Hudson formula so that it was found that the hexagonal type artificial reefs had a KD value = 1.2.
Adi Bandono, Sukmo Hadi Nugroho, Okol Sri Suharyo
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 215-222; https://doi.org/10.21107/rekayasa.v15i2.15505

Abstract:
The achievement of the vision, mission and also the target of a military institution is strongly influenced by soldiers or personnel who are human resource capital. In terms of human resources or personnel, of course, they have work motivation that must be maintained in order to survive in military organizations. Potential human resources and in accordance with their field of work will support the achievement of the organization if they are utilized optimally. This study aims to find answers about how the influence of organizational culture (X1) and job satisfaction (X2) on the work motivation of military personnel (Y) with work facilities as moderating variables (X3). The scientific method used in this research is survey research using a quantitative approach, the data analysis carried out in this study by analysis using statistical model tests. The results obtained in this study are (a) Organizational culture (X1) has a significant effect on work motivation (Y) in Institutions or Military Organizations, (b) Job satisfaction (X2) has a significant effect on work motivation (Y) in Institutions or Organizations. Military, and (c) Work facilities (X3) have a significant effect on work motivation (Y) in Military Institutions or Organizations. Based on the test results, it is also known that there is an effect of these variables after interacting with the work facilities variable as a moderating variable, the results obtained that have a significant effect on the work motivation of personnel. So it can be concluded that work facilities moderate organizational culture and job satisfaction so that it affects the increase in work motivation in military institutions or organizations.
Mukhamad Su'Udi, Arsetyo Rahardianto, Miatin Alvin Septianasari, Veren Yuliana Saputri, Dwi Setyati, Fuad Bahrul Ulum
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 143-150; https://doi.org/10.21107/rekayasa.v15i2.9799

Abstract:
Sorghum (Sorghum bicolor L. Moench) is a cereal crop that has the potential to be developed in Indonesia as a food, feed and industrial crop. Sorghum is a C4 plant that has the advantage of efficiency in hot and dry environments. Drought stress is one of the most limiting environmental factors for crop productivity worldwide, and can be caused by water deficits in the soil and in the atmosphere. On the decreasing leaf water status, the rate of CO2 assimilation and the conductance of stomata decreased rapidly. The CO2 concentration mechanism is able to saturate C4 photosynthesis under the relatively low intercellular CO2 concentration. In addition, CO2 photorespiration is likely to be repaired before it exits the bundle sheat cells. The effects of non-stomatal factors include reduced activity of photosynthetic enzymes, inhibition of nitrate assimilation, induction of premature aging, and changes in leaf anatomy. Photosynthesis in C4 plants, including sorghum, involves, others, the PEPC and Rubisco enzymes. Drought can also trigger oxidative stress, which is an environmental condition that has increased Reactive Oxygen Species (ROS) due to an over reduction of the photosynthesis process.
Badriyah Badriyah, Achmad Amzeri
Published: 6 August 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 233-240; https://doi.org/10.21107/rekayasa.v15i2.15107

Abstract:
One of the efforts to solve the problem of limited quality melon seeds is to assemble melon varieties with distinctive fruit characters in terms of shape, taste, and color of the flesh. In general, farmers choose meon seeds that have a sweet taste, flesh color, large fruit size, and have a long shelf life. Analysis of quantitative character inheritance is very important in plant breeding programs.This analysis is used to obtain genetic information consisting of the number of genes controlling the character, gene action, genetic diversity, heritability and other genetic information. This study aims to study the inheritance pattern of several quantitative characters in melon crosses. The research design was a randomized block design with eight genotypes as treatment. The results showed that there was a maternal effect on the two crosses of melon plants G1 ((PK-669 x D-612) and G3 ((PK-361 x PK-165) on the characters of fruit diameter, fruit length, fruit weight, and leaf area. Heritability values in a broad sense on all parameters ranged from 0.95-1.00.
Elli Prastyo, Puji Astuti Ibrahim, Dian Farkhatus Solikha
Published: 4 April 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 107-113; https://doi.org/10.21107/rekayasa.v15i1.13761

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%.
, Nurhasanah Nurhasanah, Laela Febby Atikasari, Ponilawati Ponilawati
Published: 4 April 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 29-35; https://doi.org/10.21107/rekayasa.v15i1.13247

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.
Aryo Sasmita, Jecky Asmura, Betharia Nurmaida
Published: 4 April 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 64-70; https://doi.org/10.21107/rekayasa.v15i1.13284

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.
Siti Fatimah, Siti Muafalah, Nurholis Nurholis, Achmad Djunaedy
Published: 4 April 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 79-86; https://doi.org/10.21107/rekayasa.v15i1.13988

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.
Umar Winarno, Desi Prianti, Mohammad Fadli, Moeljadi Moeljadi
Published: 4 April 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 100-106; https://doi.org/10.21107/rekayasa.v15i1.11576

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.
Rullie Annisa, Sri Wahyuni, Ibnu Irawan, Sayidil Anam
Published: 4 April 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 15-20; https://doi.org/10.21107/rekayasa.v15i1.12905

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.
Ibnu Irawan, Achmad Kusairi Samlawi, Hairil Budiarto
Published: 4 April 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 1-7; https://doi.org/10.21107/rekayasa.v15i1.12895

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%.
Sukmo Hadi Nugroho, Okol Sri Suharyo, Aang Chrys
Published: 4 April 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 71-78; https://doi.org/10.21107/rekayasa.v15i1.13945

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.
, Adelbert Manurung, Sujantoko Sujantoko
Published: 4 April 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 36-45; https://doi.org/10.21107/rekayasa.v15i1.13484

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.
Hadi Syafruddin, Judijanto Judijanto
Published: 4 April 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 87-91; https://doi.org/10.21107/rekayasa.v15i1.14123

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.
Rizki Mendung Ariefianto, , Wijono Wijono
Published: 4 April 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 53-63; https://doi.org/10.21107/rekayasa.v15i1.13572

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.
Siti Mutammimah, Supriyanto Supriyanto, Mohammad Fuad Fauzul Mu’Tamar
Published: 4 April 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 21-28; https://doi.org/10.21107/rekayasa.v15i1.13229

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.
Meilinda Cendana Putri, Iffan Maflahah, Supriyanto Supriyanto, Dian Farida Asfan
Published: 4 April 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 92-99; https://doi.org/10.21107/rekayasa.v15i1.13855

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
M. Arif Prabowo, Raden Faridz, Burhan Burhan
Published: 4 April 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 46-52; https://doi.org/10.21107/rekayasa.v15i1.13539

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. 
Endin Tri Hartanto, Hari Sulistyo, Anang Prasetiya Adi
Published: 4 April 2022
Journal: Rekayasa
Rekayasa, Volume 15, pp 8-14; https://doi.org/10.21107/rekayasa.v15i1.14101

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.
Maghfirotur Rohmah, M. Syafiih, Ahmad Hudawi As
Published: 28 December 2021
Journal: Rekayasa
Rekayasa, Volume 14, pp 466-471; https://doi.org/10.21107/rekayasa.v14i3.11384

Harish Wirayuhanto, Haryo Dwito Armono, Asfafur Ridlwan, Try Febrianto
Published: 28 December 2021
Journal: Rekayasa
Rekayasa, Volume 14, pp 367-372; https://doi.org/10.21107/rekayasa.v14i3.12485

Djamilah Arifiyana, Ratih Kusuma Wardani
Published: 28 December 2021
Journal: Rekayasa
Rekayasa, Volume 14, pp 360-366; https://doi.org/10.21107/rekayasa.v14i3.12391

Abstract:
Mas banana (Musa acuminata Colla) peel is a type of household waste as well as agricultural waste whose utilization still needs to be improved. In addition, among various types of heavy metals that are dangerous as contaminants in the environment, cadmium metal is a metal that is very dangerous to health even in very small amounts. Therefore, this study aims to not only utilize the waste of Mas banana peel (Musa acuminata Colla) as a biosorbent, but also to determine the optimum conditions needed to reduce cadmium metal which involves several test parameters, namely stirring time, pH and mass of biosorbent. Variations of stirring time used include 10, 20, 30, 35, and 45 minutes; variations in pH used include 1, 2, 3, 4, and 5, while variations in the mass of biosorbent used include 0.5; 1; 1.5; 2 and 2.5 grams. The results showed that the optimum conditions were obtained at a mixing time of 35 minutes, pH 5, and a mass of 2 grams of biosorbent with a reduction percentage value of 78.45%. This percentage indicates that Mas banana peel can be used as a natural adsorbent for cadmium metal. In addition, the results of the FT-IR analysis of the Mas banana peel biosorbent showed that Mas banana peel has a functional group that plays a role in the heavy metal adsorption process.
Mohammad Zaki Hartawan, Agung Pramono, Fafan Yudho
Published: 28 December 2021
Journal: Rekayasa
Rekayasa, Volume 14, pp 389-392; https://doi.org/10.21107/rekayasa.v14i3.11499

Renny Setiowati, Sundring Pantja Jati, Puji Widodo, Bambang Suharjo
Published: 28 December 2021
Journal: Rekayasa
Rekayasa, Volume 14, pp 328-333; https://doi.org/10.21107/rekayasa.v14i3.12577

Nur Laili Febriyanti, Maulidiansyah Maulidiansyah, Zainal Arifin
Published: 28 December 2021
Journal: Rekayasa
Rekayasa, Volume 14, pp 381-388; https://doi.org/10.21107/rekayasa.v14i3.11385

Youssuf Qardhawi, Nurshofi Ghaffar, Eko Prasetyo, Rudi Hermawan, Erlanda Augupta Pane
Published: 28 December 2021
Journal: Rekayasa
Rekayasa, Volume 14, pp 393-400; https://doi.org/10.21107/rekayasa.v14i3.12230

Dini Sofarini, Siti Aminah, Rina Nur Hidayah, Marissa Septa Hanifa
Published: 28 December 2021
Journal: Rekayasa
Rekayasa, Volume 14, pp 421-430; https://doi.org/10.21107/rekayasa.v14i3.12340

Abstract:
The fish diversity in Barito River is determined by diversity of zooplankton, in relation to the grazing food chain’s concept. One of the problems that occur is the quality of several key parameters in waters are no longer suitable for zooplankton and fish life. The purpose of this research were: (a) analyze the key parameters of water quality at the sampling location (b) determine the relationship between key water quality parameters and zooplankton diversity at the Barito River sampling location. The method used was a purposive sampling survey method and the shanon-wiener method. The results showed that the key parameters that met the PP No. 22/2021 Water Quality Standard for Class 2 River Water Quality.
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