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  Subjects -> SCIENCES: COMPREHENSIVE WORKS (Total: 374 journals)
Showing 201 - 265 of 265 Journals sorted alphabetically
Jurnal MIPA     Open Access  
Jurnal Natural     Open Access  
Jurnal Sains Dasar     Open Access  
Jurnal Teknosains     Open Access  
Jurnal Udayana Mengabdi     Open Access  
Karaelmas Science and Engineering Journal     Open Access  
Karbala International Journal of Modern Science     Open Access  
Kennedy Institute of Ethics Journal     Full-text available via subscription   (Followers: 10)
LOGIKA Jurnal Ilmiah Lemlit Unswagati Cirebon     Open Access  
Logo STI Science, Technology and Innovation     Open Access   (Followers: 1)
Makara Journal of Science     Open Access  
Malawi Journal of Science and Technology     Open Access   (Followers: 6)
Maskana     Open Access  
MethodsX     Open Access   (Followers: 1)
Metode & Forskningsdesign     Open Access  
Mètode Science Studies Journal : Annual Review     Open Access  
Middle East Journal of Science     Open Access  
Middle European Scientific Bulletin     Open Access   (Followers: 4)
Modern Applied Science     Open Access   (Followers: 1)
Momona Ethiopian Journal of Science     Open Access   (Followers: 5)
MUST : Journal of Mathematics Education, Science and Technology     Open Access   (Followers: 4)
Mutis     Open Access  
National Academy Science Letters     Hybrid Journal   (Followers: 3)
National Science Review     Hybrid Journal   (Followers: 1)
Natural Sciences     Open Access  
Natural Sciences Education     Hybrid Journal   (Followers: 2)
Naturen     Full-text available via subscription  
Nepal Journal of Science and Technology     Open Access  
Network Science     Hybrid Journal   (Followers: 4)
New Directions in the Teaching of Physical Sciences     Open Access   (Followers: 2)
Nordic Journal of Science and Technology     Open Access   (Followers: 2)
Nordic Studies in Science Education     Open Access   (Followers: 3)
Nova     Open Access  
Nuncius     Hybrid Journal   (Followers: 2)
OmniScience : A Multi-disciplinary Journal     Full-text available via subscription   (Followers: 1)
Open Conference Proceedings Journal     Open Access  
Open Journal of Applied Sciences     Open Access  
Orbis Cógnita : Revista Científica     Open Access   (Followers: 2)
Patterns     Open Access   (Followers: 9)
PENDIPA : Journal of Science Education     Open Access  
People and Nature     Open Access   (Followers: 4)
Población y Desarrollo - Argonautas y caminantes     Open Access  
Politique et Sociétés     Full-text available via subscription   (Followers: 1)
Portal de la Ciencia     Open Access  
Proceedings of the Indian National Science Academy     Full-text available via subscription   (Followers: 4)
Proceedings of the Linnean Society of New South Wales     Full-text available via subscription   (Followers: 2)
Proceedings of the Royal Society of Queensland, The     Full-text available via subscription  
QScience Connect     Open Access  
Quantum Science and Technology     Hybrid Journal   (Followers: 8)
RAC: Revista Angolana de Ciências     Open Access  
Rafidain Journal of Science     Open Access  
Rehabilitation Research, Policy, and Education     Hybrid Journal   (Followers: 2)
Rekayasa     Open Access   (Followers: 2)
Reportes Científicos de la FaCEN     Open Access  
Reports in Advances of Physical Sciences     Open Access  
Research     Open Access   (Followers: 6)
Research Ideas and Outcomes     Open Access  
Research Integrity and Peer Review     Open Access  
Research Policy : X     Open Access   (Followers: 4)
Respuestas     Open Access  
Reviews in Theoretical Science     Full-text available via subscription  
Revista Bases de la Ciencia     Open Access  
Revista Binacional Brasil - Argentina: Diálogo entre as ciências     Open Access  
Revista Brasileira de Iniciação Científica     Open Access  
Revista Catarinense da Ciência Contábil     Open Access  
Revista Ciencia y Tecnología     Open Access  
Revista Ciência, Tecnologia & Ambiente     Open Access  
Revista Científica de la FAREM     Open Access  
Revista Científica de la Universidad Nacional del Este     Open Access   (Followers: 3)
Revista Cientifica Guillermo de Ockham     Open Access  
Revista Científica y Tecnológica UPSE     Open Access  
Revista Conhecimento Online     Open Access  
Revista Crítica de Ciências Sociais     Open Access  
Revista de Ciencia y Tecnología     Open Access  
Revista de Información Científica     Open Access  
Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales     Open Access  
Revista de la Sociedad Científica del Paraguay     Open Access   (Followers: 1)
Revista de la Universidad del Zulia     Open Access  
Revista Eletrônica Ludus Scientiae     Open Access  
Revista Logos Ciencia & Tecnología     Open Access  
Revista MundoFesc     Open Access  
Revista Politécnica     Open Access  
Revista Saber Digital     Open Access   (Followers: 4)
Revista Sociedad y Economía     Open Access  
Revista Tecnológica     Open Access  
Revista Theoria     Open Access   (Followers: 1)
Revista UNIMAR     Open Access  
Revista UniVap     Open Access  
Revista Vivências em Ensino de Ciências     Open Access   (Followers: 1)
Rihan Journal for Scientific Publishing     Open Access   (Followers: 1)
Royal Society Open Science     Open Access   (Followers: 7)
Ruhuna Journal of Science     Open Access  
Sainstek : Jurnal Sains dan Teknologi     Open Access  
SAINSTIS     Open Access  
Sainteknol : Jurnal Sains dan Teknologi     Open Access  
Sakarya Üniversitesi Fen Bilimleri Enstitüsü Dergisi     Open Access  
Scholedge International Journal of Multidisciplinary & Allied Studies     Open Access  
Sci     Open Access  
Science     Full-text available via subscription   (Followers: 4942)
Science & Diplomacy     Free   (Followers: 3)
Science & Technology Studies     Open Access   (Followers: 3)
Science Advances     Free   (Followers: 42)
Science and Technology     Open Access   (Followers: 2)
Science Diliman     Open Access  
Science Heritage Journal     Open Access  
Science World Journal     Open Access  
Science, Technology and Arts Research Journal     Open Access   (Followers: 1)
ScienceRise     Open Access  
Sciences du jeu     Open Access  
Sciential     Open Access  
Scientific African     Open Access  
Scientific American     Full-text available via subscription   (Followers: 502)
Scientific American Mind     Full-text available via subscription   (Followers: 10)
Scientific Bulletin     Open Access  
Scientific Data     Open Access   (Followers: 6)
Scientific Journal of Mehmet Akif Ersoy University     Open Access  
Scientific Journal of Pure and Applied Sciences     Open Access   (Followers: 1)
Scientific Reports     Open Access   (Followers: 92)
Scientific World     Open Access  
Scientonomy : Journal for the Science of Science     Open Access   (Followers: 1)
Scienze Regionali : Italian Journal of Regional Science     Full-text available via subscription   (Followers: 18)
Selforganizology     Open Access  
Seminário de Iniciação Científica e Seminário Integrado de Ensino, Pesquisa e Extensão     Open Access  
Simbiótica     Open Access  
SINET : Ethiopian Journal of Science     Open Access   (Followers: 5)
Smart Science     Open Access  
South African Journal of Science     Open Access   (Followers: 2)
South American Sciences     Open Access   (Followers: 1)
South East European University Review (SEEU Review)     Open Access   (Followers: 3)
Springer Science Reviews     Hybrid Journal   (Followers: 2)
Studies in Science Education     Hybrid Journal   (Followers: 18)
Sultan Qaboos University Journal for Science     Open Access  
Tanzania Journal of Science     Open Access   (Followers: 4)
TD : The Journal for Transdisciplinary Research in Southern Africa     Open Access  
Technologies     Open Access   (Followers: 1)
TECNOSCIENZA: Italian Journal of Science & Technology Studies     Open Access   (Followers: 2)
Temas y Debates     Open Access  
The Innovation     Open Access   (Followers: 1)
The Scientific World Journal     Open Access  
The Social Studies     Hybrid Journal   (Followers: 3)
The Winnower     Open Access  
Theoria     Open Access   (Followers: 3)
THEORIA : An International Journal for Theory, History and Foundations of Science     Full-text available via subscription   (Followers: 1)
Transactions of Tianjin University     Full-text available via subscription  
Trilogía     Open Access  
TÜBAV Bilim Dergisi     Open Access  
Türk Bilim ve Mühendislik Dergisi     Open Access  
Tydskrif vir Geesteswetenskappe     Open Access  
Uluslararası Bilimsel Araştırmalar Dergisi (IBAD)     Open Access   (Followers: 1)
UNED Research Journal / Cuadernos de Investigación UNED     Open Access  
Uni-pluriversidad     Open Access  
Uniciencia     Open Access  
Universidad, Ciencia y Tecnología     Open Access  
Universitas (León)     Open Access  
Universitas Scientiarum     Open Access  
Unnes Science Education Journal     Open Access  
Vilnius University Proceedings     Open Access  
Walailak Journal of Science and Technology     Open Access  
WikiJournal of Science     Open Access  
World Scientific Research     Open Access  
Zeitschrift für Didaktik der Naturwissenschaften     Hybrid Journal  
Образование и наука     Open Access   (Followers: 1)
Східно-Європейський журнал передових технологій : Eastern-European Journal of Enterprise Technologies     Open Access   (Followers: 3)

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Rekayasa
Number of Followers: 2  

  This is an Open Access Journal Open Access journal
ISSN (Print) 0216-9495 - ISSN (Online) 2502-5325
Published by Trunojoyo University Homepage  [5 journals]
  • Analisis Tekno-Ekonomi Produksi Gula Reduksi dari Biomassa Ampas Tebu
           Melalui Hidrolisis Air Subkritis

    • Authors: Maktum Muharja, Siska Nuri Fadilah, Nur Fadhilah, Rizki Fitria Darmayanti, Arief Widjaja, Achri Isnan Khamil
      Pages: 107 - 116
      Abstract: Subcritical water hydrolysis of bagasse requires energy to convert lignocellulosic biomass into fermentation-ready sugars. Bagasse biomass has the potential to be used as raw material for the production of reducing sugar. This study evaluates the effectiveness of the hydrolysis process using an oven and autoclave through economic and energy analysis. The variables used were hydrolysis time of 20-60 minutes, oven temperature of 110-170°C, and autoclave temperature of 120-130°C. Reduced sugar concentration was obtained from analysis using the DNS (dinitro salicylic acid) method. The results of the analysis show that time and temperature have a significant effect on the yield of reducing sugar. The highest reduced sugar concentration from subcritical water hydrolysis using an oven was 27.4 g/L at 170°C operating conditions for 60 minutes with a total cost of Rp 351,744 and energy requirement of 480 W.h. In hydrolysis using an autoclave, it was obtained at 14.7 g/L at 125°C for 40 minutes with a total cost of IDR 923,079 and energy requirements of 1,936.67. Hydrolysis using an oven is more recommended than autoclaving because it is economical and has lower energy consumption.
      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.17243
      Issue No: Vol. 16, No. 2 (2023)
       
  • Resistance of Klebsiella Sp. Isolated From Chicken and Cages to
           Chloramphenicol

    • Authors: Rahmat Hidayat, Fachriyan Hasmi Pasaribu, Sri Mulatsih, Akhmad Arif Amin
      Pages: 117 - 121
      Abstract: Klebsiella bacteria is one of the normal flora in poultry that has developed antibiotic resistance. This is reinforced by reports of the incidence of resistance by Klebsiella bacteria in various countries which is quite high. This study aimed to identify the presence of Klebsiella sp. bacteria in chickens and cages, as well as their resistance status to chloramphenicol in relation to the Minister of Agriculture Regulation No. 14/2017. The series of identification included culture, macroscopic and microscopic observations, biochemical tests, and fermentation tests. Antibiotic resistance tests using chloramphenicol disks referring to the Kirby Bauer method. The identification results showed 6 positive samples from 60 samples taken from chickens and 2 positive samples from 21 samples taken from cages. Resistance testing of 8 Klebsiella sp. isolates showed 6 sensitive, 1 intermediate and 1 resistant isolates to chloramphenicol. This is an indication that the Minister of Agriculture Regulation No. 14/2017 is quite effective in prohibiting the use of chloramphenicol in chicken farms.
      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.20277
      Issue No: Vol. 16, No. 2 (2023)
       
  • Efek Penambahan Ekstrak Jahe (Zingiber officinale Rosc.) Serta Rasio
           Glukosa dan Fruktosa Pada Sucrose-Free Hard Candy

    • Authors: Supriyanto Supriyanto, Mojiono Mojiono, Meriya Widianti Prastika Dewi
      Pages: 122 - 131
      Abstract: Hard candy is a non-crystalline product with a hard texture, shiny appearance and clear cooked at high temperature (140-150°C). One of the main ingredients in making hard candy is sucrose which can accelerate the growth of Streptococcus mutans bacteria, the main cause of dental caries. Thus, researchers conducted a study making sucrose-free hard candy ginger extract products using fructose and glucose syrup as sugar substitutes (sucrose) which are expected to inhibit the growth of Streptococcus mutans bacteria. The purpose of this study was to determine the effect of the ratio of fructose and glucose on the characteristics of sucrose-free hard candy, ginger extract (Zingiber officinale Rosc.) and find out the best formula in making sucrose-free hard candy, ginger extract (Zingiber officinale Rosc.) based on sensory tests. This research method uses Non-Factorial Complete Randomized Design (RAL). The study parameters include Ph, dissolving time, sensory, RGB color, and antibacterial. The effect of the ratio of fructose and glucose on the characteristics of sucrose-free hard candy ginger extract (Zingiber officinale Rosc.) is that the less fructose added and the more glucose, the higher the Ph of the candy, the longer the soluble time, the brighter color produced and the weaker the inhibitory power. Based on the results of sensory tests, it can be concluded that the best formulation in making sucrose-free hard candy ginger extract (Zingiber officinale Rosc.) is formula 3 with a ratio of glucose and fructose of 80:30 grams.

      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.20158
      Issue No: Vol. 16, No. 2 (2023)
       
  • Analisis Beban Kerja dengan Pendekatan Cardiovascular (CVL) dan Subjective
           Workload Assesment Technique (SWAT) : Studi Kasus Pengemudi Go-Jek

    • Authors: Muhammad Rifqi Hari Nugroho, Akmal Suryadi
      Pages: 132 - 141
      Abstract: Currently the mobility of the population is getting higher and higher which causes congestion and the emergence of demands to move from one place to another by using an online motorcycle taxi. Being an online motorcycle taxi driver is inseparable from physical and mental activities such as driving, controlling vehicles, carrying goods ,waiting for orders, interacting with customers, finding destination addresses, operating online motorcycle taxi applications and others. This makes the workload of online motorcycle taxi riders both physically and mentally even greater. this study aims to determine the physical and mental workload on the Go-Jek driver in the village of tongue Kulon. This research uses a quantitative approach. The population of this study is Go-Jek drivers who are active as a whole in the village of tongue Kulon which amounted to 35 people and a sample of 26 respondents. The results of this study found that the physical workload using the percentage of Cardiovascular Load (CVL) showed that Go-Jek drivers have a physical workload with an average of %CVL of 31%. Then the results of the SWAT method for Go-Jek drivers obtained values in the Effort dimension of 23.69%, then for Time of 64.43%, and for Stress of 11.89%. Then the most influential is the Load Time with an average load value of 64.43%. This means that Gojek drivers significantly feel the burden of time is more dominant in affecting their work.
      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.15897
      Issue No: Vol. 16, No. 2 (2023)
       
  • Respon Air Perasan Ubi Jalar Ungu (Ipomoea Batatas L. Poiret) Pada Pakan
           Terhadap Peningkatan Warna Ikan Komet (Carassius Auratus)

    • Authors: Jaziroh Rizky Wulandari, Sri Oetami Madyowati, Maria Agustini, Achmad Kusyairi
      Pages: 142 - 147
      Abstract: Comet fish (Carassius auratus) is a freshwater ornamental fish which is quite well known among the public. The attractiveness of ornamental fish can be measured by its brilliant color, shape, physical fitness, behavior and state of health or stamina. Purple sweet potato (Ipomoea batatas L. poiret) has high antioxidant compounds, in addition to the anthocyanins present in sweet potatoes, vitamin C, vitamin E, lutein, zeaxanthin, and β-carotene which are carotenoid antioxidant pairs. This study aims to determine the increase in the color of koi fish after being given artificial feed added purple sweet potato. The method used in this study was an experimental method with a completely randomized design consisting of 4 treatments, tested for 30 days. The comet fish used were 2-3 months old and 5-6 cm in size. From the results of the study, the addition of purple sweet potato juice to the feed had an effect on increasing the color of comet fish whereas treatment C with a dose of 50 ml resulted in an increase in comet fish color with the highest average of 28, 53 RGB.
      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.19720
      Issue No: Vol. 16, No. 2 (2023)
       
  • TWO (2) DIMENSIONAL HYDRODYNAMIC MODELING OF SURFACE SEA CURRENTS IN THE
           VILLAGE WATERS OF BINTAN REGENCY

    • Authors: Nur Anisa, Mario Putra Suhana, Harish Wirayuhanto
      Pages: 148 - 155
      Abstract: Information related to ocean currents is not yet available in Berakit Village waters, ocean currents are an important parameter to determine the condition of a waters. An alternative that can be used to determine the condition of ocean currents is to use hydrodynamic modeling. The purpose of the study was to analyze the distribution pattern and characteristics of surface ocean currents. This research was conducted by conducting 2-dimensional hydrodynamic modeling simulating ocean currents for 1 (one) year in December 2020-November 2021 using MIKE 21 software by sampling in 6 (six) different conditions, namely at the highest tide, lowest tide, high tide. towards the ebb and flow of the full moon, the ebb towards the negligible tide, the tide towards the ebb tide and the ebb towards the negligible tide. The model results were validated by the RMSE formula with a value of 2%, the model results were very good, so that they could be used as a reference in providing an overview of the real conditions of the pattern and current distribution at the research location. The movement of ocean currents at the time of the full moon and negligible dominant currents move towards the south of the waters, while at the time of the full tide and negligible the dominant currents move towards the north of the waters. In the north season, the current velocity ranges from 0.00006 m/s-0.125 m/s with the dominant movement towards the north. East monsoon currents move predominantly north and south with speeds ranging from 0.0000003 m/s-0.129 m/s. In the south monsoon the dominant current moves to the north and south at a speed of 0.0000007 m/s-0.13 m/s. in the west season, the dominant current moves to the north and south at a speed of 0.00001 m/s-0.12 m/s. The speed of the dominant ocean currents is greater at high tide compared to low tide, this is due to differences in sea level elevation in the opposite direction of motion. 
      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.17227
      Issue No: Vol. 16, No. 2 (2023)
       
  • Analisis Prediksi Ancaman Militer dan Pemilihan Teknologi Senjata Rudal
           Pada Coastal Defense Concept di Laut Natuna Utara

    • Authors: Wahyu Endriyanto
      Pages: 156 - 163
      Abstract: The military threat in the North Natuna Sea is now becoming more real and can no longer be avoided. This study aims to carry out threat forecasting analysis and selection of missile weapons technology (guided missiles) on the concept of Coastal Defense in the North Natuna Sea. This study uses the Linear Regression method using Excel to predict threats that will continue to occur within the next 5 (five) years. Furthermore, this study also uses the Analytic Hierarchy Process (AHP) method to select the most appropriate missile weapon technology to deal with threats that occur in the North Natuna Sea. The results of the study obtained a Linear Regression equation with the equation Y = 253.952561 + 7.1855428X, it can be explained that if the value is X = 0 then Y = 253.95, then the value of x is 7.186x which has a positive value, meaning the influence of the variable x is positive on variable Y. When X the military budget increases, Y (military strength/defense posture) will also increase. Furthermore, the selection of the best alternative for coastal defense missiles using the AHP method consists of four criteria for range, price, explosive power, and logistical continuity as well as the four best alternative missiles in the world, the results of the analysis selected the 3M-54E missile from Russia with a weight of 41.9 %.   

      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.19731
      Issue No: Vol. 16, No. 2 (2023)
       
  • Integration of Customer Needs in Sativa Mouthwash Design With Quality
           Function Development (QFD) Approach

    • Authors: Lusi Zafriana, Ernie Maduratna Setiawatie
      Pages: 164 - 170
      Abstract: Public awareness of oral-hygiene and health has influenced the increase demand for mouthwash products. To support the green innovation program, a mouthwash made from herbs and halal is needed. Sativa mouthwash is an innovative product using 3% Nigella Sativa extract. The QFD method is used as an evaluation of the productivity of Sativa mouthwash through the preparation of the HoQ matrix. It shows the level of connectedness between Customer and Technical Importance to get priority on the main technical interests that must be carried out immediately by the production company. The results of HoQ matrix calculation shows the highest-ranking attributes of the product is Nigella Sativa content, Raw Material Management, and Halal Label Design. The technical priority to achieve the customer interest attributes is packaging type. This means that the attributes of adding and processing Nigella Sativa ingredients that are right and labelled as halal have unique characteristics that greatly affect the sales productivity of Sativa Mouth Wash products. However, on the attribute of the type of packaging, Sativa Mouth Wash has not yet produced in sachets or small bottles which provide convenience and practicality that is needed by the customers
      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.19950
      Issue No: Vol. 16, No. 2 (2023)
       
  • Strategi Pemasangan Radar Pantai Untuk Identifikasi Potensi Ancaman Laut
           di Wilayah Selatan Pulau Jawa

    • Authors: Provid Ariantoko, Pujo Widodo, Herlina Juri Risma Saragih, Panji Suwarno, Endro Legowo, Moch Yurianto
      Pages: 171 - 178
      Abstract: The conditions of vulnerability and potential security threats in the sea area of the southern part of Java Island and the level of ability of elements operating in the area are still inadequate both in quality and quantity. This thesis uses qualitative research methods. Some of the vulnerabilities that can occur include illegal fishing, smuggling, pollution at sea, illegal crossing, terrorism at sea, and people smuggling. These threats can endanger Indonesia's interests in many aspects such as defense and security, the economy, and territorial sovereignty. Therefore a plan is needed to conceptualize the installation of a coastal radar to improve security in the area. The IMSS (Integrated Maritime Surveillance System) radar, which is already operating in the Malacca Strait area as an empirical example, will develop the coastal radar concept in the southern region of Java Island. With the existence of a coastal radar in the area that functions as an early warning system, it is hoped that all forms of threats and violations can be anticipated very well. The addition of a security element in the sea area of the southern part of Java Island in the form of installing a coastal surveillance radar is very important to implement given that the level of capability of the security elements operating in the area is considered to be insufficient for security in the wider sea area.
      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.19713
      Issue No: Vol. 16, No. 2 (2023)
       
  • Effect of Work Stress, Extrinsic and Intrinsic Motivation on Job
           Satisfaction and Employee Performance

    • Authors: Rensi Pradias Sari, Sukmo Hadi Nugroho
      Pages: 179 - 188
      Abstract: Aspects of human resources is one of the important factors that must be considered in the company. In order for companies to survive in the face of increasingly fierce business competition, management needs to make changes within the company with the aim of being able to further improve employee performance so that it is more optimal. The problem that is often faced by every company is regarding employee performance which tends to decline. One of the factors is the work stress experienced by employees. This study aims to explore the effect of job stress and extrinsic and intrinsic motivation on employee performance through the mediation of job satisfaction at the financing company PT BFI Finance Indonesia Tbk. This study uses data collection methods survey and distribution of questionnaires online, respondents were selected by the method purpose sampling. The sample of this research are employees Head Office working in parts Project Management Office, Asset Management and Human Capital at the staff level with a working period of more than 6 months. Data analysis techniques using Structural Equation Modeling (SEM) with LISREL. The results of this study explain that the variables that influence job satisfaction and employee performance are low levels of stress and intrinsic motivation. There are findings where extrinsic motivation has no positive effect on job satisfaction and employee performance.
      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.19697
      Issue No: Vol. 16, No. 2 (2023)
       
  • Uji Efektivitas Ulat Hongkong (Tenebrio molitor L.) dalam Degradasi Sampah
           Plastik Oriented Polypropylene

    • Authors: Estin Nofiyanti, Rubiansyah Dio Lazuardi, Melly Mellyanawaty, Gatut Ari Wardani
      Pages: 189 - 194
      Abstract: Oriented Polypropylene (OPP) plastic is a thermoplastic polymer that is widely used for the benefit of plastic product packaging in the pharmaceutical, cigarette, shampoo, detergent, textile, food, and beverage industries. OPP plastic has a high coefficient of thermal expansion, is susceptible to UV degradation, has poor resistance to solvents, is difficult to paint due to poor bonding properties, is highly flammable, susceptible to oxidation, and difficult to decompose naturally when it becomes waste. This study aimed to determine the ability of the Hong Kong caterpillar to degrade OPP plastic waste. This research method used a completely randomized design consisting of 4 treatments and 3 replications. The various treatments given were OPP 0.23 g for 120 caterpillars (V0); OPP 0.17 g: Bran 0.23 g for 120 caterpillars (V1); OPP 0.11 g: Bran 0.23 g for 120 caterpillars (V2); and OPP 0.06 g: Bran 0.23 g for 120 caterpillars (V3). The results showed that the feeding of OPP and rice bran affected the degradation rate of OPP plastic. The highest percent degradation value was obtained in the V3 treatment at 50% and the most optimal biodegradation rate occurred in the V1 treatment of 0.02 mg/day.
      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.19321
      Issue No: Vol. 16, No. 2 (2023)
       
  • Analisis Waktu dan Biaya Penyelesaian Proyek Transmisi 150 kV Dengan
           Pendekatan Critical Path Method dan Time Cost Trade Off

    • Authors: Muhamad Eriq Ashari, Haryo Dwito Armono
      Pages: 195 - 203
      Abstract: The construction of the 150 kV Transmission electricity infrastructure by PT PLN (Persero) is an assignment from the Government in order to support electricity growth in Indonesia. Several 150 kV Transmission projects experienced delays in project completion due to inaccurate timing and project completion costs. The construction project of the 150 kV transmission involves engineering, procurement, construction, and commissioning activities, requiring careful calculations of time and costs while considering resources (Man, Material, Machine, and Method). The Critical Path Method (CPM) is used as the deterministic analysis approach for time analysis, while the Time Cost Trade-Off (TCTO) method is employed when there is a potential for project delays, acceleration, or cost overrun. The combination of the CPM and TCTO methods is suitable for project activities that are precisely known, while considering both parallel and serial work. Based on the research results, the 150 kV transmission project has 13 critical paths. The acceleration scheme that significantly impacts time and cost is the acceleration during the construction phase, and changes in all resource variables (Man, Material, Machine, and Method) affect both time and cost. However, a change in a single resource variable, namely Method, may impact time but not necessarily cost.
      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.20501
      Issue No: Vol. 16, No. 2 (2023)
       
  • Pengaruh Suhu Perkerasan Terhadap Umur Perkerasan Lentur Menggunakan
           Metode Analitis

    • Authors: Nola Riwibowo, Fibia Sentauri Cahyaningrum, Taruna Firlian Tama, Friska Amelia
      Pages: 204 - 211
      Abstract: This study will discuss the effect of temperature design with variations in air temperature between 24 ºC and 30 ºC on the life of flexible pavements. The obtained secondary field data was processed using the Nottingham Design Method. Furthermore, the results of the data processing are used to calculate the strain value with the BISAR 3.0 program (Bitumen Stress Analysis in Roads). The strain values resulting from the BISAAR 3.0 program analysis in the form of asphalt mix horizontal tensile strain (εt) and subgrade vertical strain (εz) are used to calculate the life of flexible pavements. The results of the analysis show that when using fatigue crack damage criteria, a temperature increase of 5.8% will cause a decrease in the life of flexible pavement by 0.7% (critical condition) or 0.6% (failed condition). However, when using the criteria for permanent deformation damage, a temperature increase of 5.8% will reduce the life of flexible pavement by 1.5% (critical condition) or 1.0% (failure condition).
      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.19043
      Issue No: Vol. 16, No. 2 (2023)
       
  • Pengendalian Persediaan Bahan Baku Menggunakan Metode Min-Max Stock

    • Authors: Abyan Thariq Fadhilah, Joumil Aidil Saifudin
      Pages: 212 - 218
      Abstract: The problem of planning and controlling inventory is one of the most important things that every company must face. This study aims to determine the description of raw material inventory management using Min-Max Stock at PT Delta Jaya Engineering and to determine the cost of inventory disbursed by using the Min Max Stock method. Data collection is preferred to use primary data from interviews and observations to the company. While the secondary data obtained from the company's historical data. The results of this study found that theoretically shows the minimum and maximum limit value of stock, safety reserve (safety stock), and the level of reorder (Q) is different for each raw material. In addition, by using the policy proposal with the min–max stock method, the cost calculation results show that the costs incurred by the company each year are lower because there are no raw materials that are over stock or out of stock.  
      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.15384
      Issue No: Vol. 16, No. 2 (2023)
       
  • The Implementation of Bantu Warga Apps and Metabase for Spatial Data
           Processing In Surabaya

    • Authors: Alfandino rasyid, Sritrusta Sukaridhoto, Muhammad Agus Zainuddin, Rizqi Putri Nourma Budiarti, Ubaidillah Zuhdi, Agus Imam Sonhaji, Yohanes Yohanie Fridelin Panduman, Luqmanul Hakim Iksan
      Pages: 219 - 225
      Abstract: Civil registration and vital statistics (CRVS) is known as an essential supporting system for effective policy-making and service delivery. Its primary purpose is establishing an individual's legal identity and vital events to ensure all citizens get their rights well. Furthermore, an advanced level of CRVS is equipped with a forecasting system to serve more useful data. This paper discusses the potential benefits and challenges of using Metabase and Bantu Warga as civil ministry support systems. The spatial data visualization system using open-source Metabase ran well and resulted in many visualization geospatial maps like birth, marriage and divorce, education, and employment. The forecasting autoregression model configuration and cumulative sum dataset reach the best error result in 1056618. The other aspects, like the self-isolation management system, civil documents classification system, and OCR system, have a good result.
      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.20509
      Issue No: Vol. 16, No. 2 (2023)
       
  • Studi Komparasi Stabilitas Pipa Bawah Laut dengan DNVGL-RP-F109 dan Elemen
           Hingga

    • Authors: Nafisa Nandalianadhira, Mochammad Fathurridho Hermanto
      Pages: 226 - 234
      Abstract: Deployment under the sea without being excavated or buried is the most effective alternative. The subsea pipeline must be ensured to be stable on the seabed, not experiencing movement when exposed to environmental forces. There are two main things that must be analyzed in the design process and stability analysis of subsea pipelines, hydrodynamic and hydrostatic forces. In the subsea pipeline design process, one of the most important steps is determining the wall thickness. One standard that is widely used is DNVGL-ST-F101. The diameter and thickness of the subsea pipeline are important parameters for determining subsea pipeline stability. The relationship between the forces acting to the subsea pipeline and the resistance of the soil (seabed) has been regulated in DNVGL-RP-F109. In addition, stability calculations can also be performed based on subsea pipeline modeling on the seabed using the finite element method. Based on these two methods, the vertical and lateral stability of the subsea pipeline can be determined. If the subsea pipeline is unstable, it is necessary to add concrete coating. Based on the pipe properties and environmental data, the wall thickness of the subsea pipeline is 18.203 mm. To be able to meet vertical and lateral stability for operating and installation conditions, 41 mm thick concrete coating is required. The greatest hydrodynamic force occurs in operating condition of 165.693 N/m based on DNVGL-RP-F109 and 154.150 N/m based on finite element. The difference of those result is only 6.96%.
      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.18804
      Issue No: Vol. 16, No. 2 (2023)
       
  • Fuzzy Logic dalam Pengontrolan Nilai Intensitas Cahaya LED pada Mini Plant
           Factory Budidaya Tanaman Pak Choy (Brassica Chinensis L.) Hidroponik

    • Authors: Choirul Umam, Fahmi Arief Rahman, Mohammad Syafii, Nurul Hidayat
      Pages: 235 - 242
      Abstract: Ideally, the Pak Choy plant (Brassica Chinensis L) is cultivated with microenvironmental conditions of temperature 150C- 320C, humidity 60% - 80% and the same intensity of sunlight as other vegetable plants, namely in a vegetative vase of 300-400 micromols/m2/second and a period of generative 500-1000 micromols/m2/sec . The challenge of agriculture today is to meet the increasing need for food with limited land and uncertain plant microenvironmental conditions, one solution to this problem is planting using a plant factory system. Fuzzy logic has an effective method for controlling plant factory control systems, due to its flexibility and simple calculations. The purpose of this research is to find the PWM value in the plant factory control system that suits the optimal needs of pak choy vegetable cultivation. There are 4 stages in the research, namely the primary data input of the LED plant factory, Fuzzyfication, Fuzzy Interface System and Defuzzification. Data was taken using a lux meter and there were a total of 56 fuzzy rules and 4 fuzzy rules that did not have a value of 0. The lighting level/light intensity control system based on fuzzy logic was obtained with a PWM (Pulse Width Modulation) value of 872.1662 for a light intensity set point of 8000 Lux.
      PubDate: 2023-08-12
      DOI: 10.21107/rekayasa.v16i2.15347
      Issue No: Vol. 16, No. 2 (2023)
       
  • Identifikasi Kekuatan Butt Joint dan Lap Joint pada Pengelasan Konstruksi
           Kapal

    • Authors: Bagiyo Suwasono, Muhammad Farizal, Nur Yanu Nugroho, Didik Hardianto
      Pages: 243 - 249
      Abstract: The joining of steel in ship construction was carried out through welding technology. One of the joining processes used two types of welded joints, namely butt and lap joints. This study identified the strength of the test material from ASTM A36 steel plates at welded joints by standardizing the tensile test. Experimental activities using a tensile testing machine and simulation activities using SolidWorks. The average tensile test values for butt and lap joints show yield strengths of 288.89 and 200 N/mm2, final strengths of 419.11 and 280 N/mm2, reduction of cross-sectional areas of 49.33 and 43.33%, strain 7% and 18.67%, modulus of elasticity 60.81 and 15 N/mm2. Tensile test simulations for butt and lap joints showed plastic deformation in the weld face, root, toe, and HAZ area. Experimental and simulated difference values for butt joints range from 941.67 to 1,519.67 N/m2, and lap joints range from 1,030 to 4,694 N/m2. The final results show that SMAW welding with the butt joint type has a higher strength value than the lap joint.
      PubDate: 2023-08-13
      DOI: 10.21107/rekayasa.v16i2.19914
      Issue No: Vol. 16, No. 2 (2023)
       
  • Rancang Bangun Mesin Screw Extruder Pencetak Arang Briket

    • Authors: Hadi Santosa, Yuliati Yuliati
      Pages: 250 - 256
      Abstract: Efforts to use renewable energy in a sustainable manner aim to maximize the resources and potential of renewable energy as an alternative energy source and minimize the use of petroleum or fossil energy. One of the alternative energy sources in the form of biomass is bio briquettes. One of the technological stages of making bio briquettes is the process of compaction or densification of the briquette material. Based on this, the purpose of this research is to design a screw extruder machine for bio briquette printing. This tool is designed to be energy efficient, easy to operate and maintain. The research method used is the calculation and analysis of machine elements in the initial design of the tool, the design of materials / materials and the manufacture of bio briquette materials for testing tools in an effort to test the performance and technical specifications of the tool. The result of this research is that there are three stages of the bio briquette printing screw extruder, namely the feed section, compression section and metering section. The technical specifications are that this tool is primarily driven by an electric motor with a rotating speed of 1400 rpm and an electrical power of 2 HP, the V belt used is a trapezoid type A. The screw extruder has an extruder turning torque of 0.055 kg m and an extruder driving power of 0.042 HP. The output of this machine is continuous with a briquette capacity of 200 kg/hour.
      PubDate: 2023-08-13
      DOI: 10.21107/rekayasa.v16i2.14176
      Issue No: Vol. 16, No. 2 (2023)
       
  • Pemakaian Temporary Tower untuk Optimalisasi Penyelesaian Rekonduktoring
           dan Penggantian Tower Saluran Udara Tegangan Tinggi (SUTT) 150 KV

    • Authors: Muhammad Iqbal, Haryo Dwito Armono
      Pages: 257 - 264
      Abstract: The use of temporary towers is a solution to shorten the outage time. Temporary Tower is used as a tool in reconductoring work and tower replacement. The study by calculating the Budget Plan Cost (RAB) and schedule analysis using Microsoft Project Application to determine the comparative duration of time required to complete the reconductoring work and tower replacement between using temporary tower and without temporary tower. From the time schedule created, it will be known which work method uses a shorter duration of time so that it can save or speed up the outage time. This study will produce what kind or type of conductor is appropriate in the context of replacing conductors or reconductoring SUTT 150 kV A - C, resulting in a reconductoring and tower replacement work schedule that is 15 days faster when using a temporary tower and reduces the outage time by about 132 days or about -89%. However, it requires an additional cost of Rp 1,872,217,454, which is still much smaller than the loss due to outages if the work is not done with a temporary tower.
      PubDate: 2023-08-27
      DOI: 10.21107/rekayasa.v16i2.21105
      Issue No: Vol. 16, No. 2 (2023)
       
 
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