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Sistem Ujian Online Essay Kolektif Berbasis Gambar Studi Kasus Kampus PTKI Medan Abdul Azis Rahmansyah; Poltak Evencus Hutajulu
JURNAL MEDIA INFORMATIKA BUDIDARMA Vol 5, No 3 (2021): Juli 2021
Publisher : STMIK Budi Darma

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30865/mib.v5i3.3029

The Covid-19 pandemic is a disaster for all of us, Vocational Education is also affected by the Covid-19 pandemic which forces online lectures, one of which is at the Industrial Chemical Technology Polytechnic (PTKI), in the implementation of the exam at PTKI Medan carried out collectively with questions exam in the form of an essay. There have been many studies on online essay exams but the scope of the discussion is for automatic correction or similarity based on text input. In vocational education, especially PTKI Medan, which has a test that is not limited to text input but there are calculations. Another weakness of text input is that the answers can be more easily copied and pasted by students. This research was carried out for 1 year starting from Odd semester 2020 to Even 2020. The method in developing information systems uses the waterfall model with the stages of needs analysis, system design, coding, implementation and the last stage of system maintenance. From the results of the research in the odd semester of 2020, the researchers used a text-based online essay exam model, but many weaknesses were found, one of which was the ease of students in using answers from the internet which were directly entered into the answer column. At the maintenance stage, the researcher updates the system by changing the image-based exam model, so students must write their answers on paper and then upload the answers to the website. The file upload system can overload the server if it is not controlled, one of the techniques used is to compress image files uploaded by students to the system and the maximum size can be compressed up to 78.48% from 1329 Kb to 286 Kb for this type. png data. In addition, to make it easier for lecturers to check answers, use the ezoom.js feature as a means to view answers in the form of images that are useful for zooming in, zooming out, rotating the answer images. Ezoom.js is a javascript that can be installed on php-based websites

Kajian Pemanfaatan Cangkang Sawit Sebagai Pengganti Solar Industri Pada Sistem Thermal Oil Heater di Pabrik Resin Sari Farah Dina; Poltak Evencus Hutajulu; Taufiq Bin Nur; Justaman Arifin Karo-karo
REACTOR: Journal of Research on Chemistry and Engineering Vol 3, No 2 (2022): Published in December 2022
Publisher : Politeknik ATI Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.52759/reactor.v3i2.58

The National Energy Policy to develop the use of renewable energy has opened up opportunities for industry to develop the use of biomass. A study on the use of palm shells as a substitute for industrial diesel in a thermal oil heating system at a natural rubber resin factory in North Sumatra has been carried out. All information and data on the operation of TOH were obtained through secondary data collection and direct discussions in the field. The secondary data obtained include the type and specification of the heater, the characteristics of the thermal oil (type, flow rate, temperature inlet and outlet of the heater), fuel consumption/hour and the characteristics of palm shells. From the study conducted, it can be concluded that during the process of heating thermal oil which takes place gradually in the TOH system using industrial diesel, it has a heat capacity of 1,500,000 kcal/hour, but the maximum heat that is useful for heating thermal oil is 694,396 kcal/hour with maximum thermal efficiency is 80.69%. Estimated consumption of palm kernel shells required to heat thermal oil on the assumption of 70% thermal efficiency as a substitute for energy supplied by industrial diesel is 237 kg/hour. The savings from this fuel replacement is estimated Rp.3.286.800.000/year.

Pengendalian Kualitas Derajat Pemisahan Hidrolisa Crude Fatty Acid Menggunakan Pendekatan Peta Kendali dan Kapabilitas Proses Emil Salim P. Siregar; Poltak Evencus Hutajulu; Febrianti Sitorus
Journal Warta AKAB Vol 46, No 2 (2022): Warta AKAB
Publisher : Politeknik AKA Bogor

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55075/wa.v46i2.160

Acid Value and Saponification Value are used as parameters to measure Fatty Acid quality in Splitting Triglycerides from vegetable oils by hydrolysis process, Crude Palm Kernel Oil separation process to form Crude Fatty Acid and Glycerin in the Oleochemical Industry and is a reference for achieving the capability separation process in the Splitting Column by Splitting Degree of Hydrolysis method. From the results our study, we found that the tenth data from our test parameters observations are out of control but within specified range. Quality test parameters set for acid value and saponification value are in the range of 250 – 254 and 252–255 mg.KOH.g-1. The results of quality control at 252.411 and 253.55 mg.KOH.g-1 by a range 0.78 and 0.651, respectively for each parameter. The average of two parameters for hydrolysis conversion is 99.54 %, This result meets industry standards to produce good quality Crude Fatty Acid. The process capability value for Crude fatty acid production for parameter acid and saponification value are 1.45 and 1.30 respectively. Both values indicate that the hydrolysis separation process is running very well. The quality control Splitting Degree of Hydrolysis method using a control chart approach and process continuous capability for the resulting product can be used as a consideration in determining the quality of fatty acids and predicting fatty acid composition.

Pengaruh Kuat Arus Pengelasan SMAW Terhadap Kekuatan Tarik dengan Metode Double Joint pada Material Baja Carbon Bukhari Bukhari; Herry Darmadi; Muhammad Iqbal Harapan Muslim Siregar; Poltak Evencus Hutajulu; Dian Kurnia; Noer Akbar Tambunan
JURNAL ILMIAH MOMENTUM Vol 19, No 1 (2023)
Publisher : Universitas Wahid Hasyim

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36499/jim.v19i1.8048

Penelitian ini bertujuan untuk mengetahui pengaruh kuat arus pengelasan terhadap kekuatan tarik hasil pengelasan bahan baja carbon dengan metode SMAW menggunakan elektroda E7018. Dalam penelitian ini juga dilakukan pengujian kuat arus pengelasan dengan beberapa variasi kuat arus yaitu 80A, 100A, 120A, pengujian ini akan diketahui daya tahan material baja carbon yang telah dilakukan pengelasan dan direpresentatifkan pada grafik kuat arus vs tegangan Tarik. pada pengelasan bahan baja carbon dengan metode SMAW menggunakan elektroda E7018 melalui metode Non Destructive Test (NDT) pada penelitian ini didapat hasil pengujian yang paling sesuai dari tiga hasil pengujian yang telah dilakukan yaitu dengan menggunakan arus pengelasan 120 Ampere dengan hasil pengujian tarik sebesar 1,2063 kgf/mm2. Untuk hasil pengujian cacat las dengan metode penetrant maka di peroleh arus yang paling bagus dikarenakan mengalami kecacatan paling sedikit dalam melakukan pengelasan bahan baja carbon yaitu dengan menggunakan arus 120 Ampere. Manfaat dari penelitian ini yaitu diketahuinya arus yang sesuai pada proses pengelasan bahan baja carbon dengan metode SMAW menggunakan elektroda E7018 serta dapat mengetahui kekuatan dan kualitas hasil pengelasan dengan metode Non Destructive Test (NDT) yang terbaik yang mana dengan menggunakan arus 120 Ampere, diketahui terdapat cacat las porositas. porositas yang terjadi dapat berupa cacat pengelasan dengan hasil pengelasan yang berlubang-lubang keci l pada weld metal (logam las) baik berada dipermukaan maupun didalamnya

Karakterisasi Komposit Polimer dengan Matriks Polistirena dan Bahan Pengisi dari Berbagai Limbah Pabrik Kelapa Sawit Hidayani, Tengku Rachmi; Hutajulu, Poltak Evencus; Marbun, New Vita Mey Destty; Pardede, Erwin; Paramitha, Ratih; Nasution, Reni Silvia
REACTOR: Journal of Research on Chemistry and Engineering Vol 5, No 1 (2024): Published in June 2024
Publisher : Politeknik ATI Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.52759/reactor.v5i1.115

The first stage of this research was to make polystyrene grafted with maleic anhydride for making the couping agent with other filling compound. In the second stage, the polystyrene matrix grafted with maleic anhydride was combined with filler material derived from palm oil mill waste using the dry mixing method with an internal mixer. Among several variables tested, the optimum composition of the polymer composite was found to be Polystyrene grafted with maleic anhydride: sludge: boiler ash in a ratio of 60:25:15. This composition exhibited a Young's modulus of 856.752 MPa, a tensile strength of 6.057 MPa, and an elongation at break of 0.775%. Differential Scanning Calorimetry (DSC) testing revealed a glass transition temperature of 403.22°C, a crystallization temperature of 426.39°C, and a cross-linking indication temperature of 478.64°C. Scanning Electron Microscopy (SEM) tests showed an even distribution of the material. Fourier-transform infrared (FT-IR) spectroscopy indicated a decrease in absorption peaks at 3024.94 cm⁻¹ and 3025.15 cm⁻¹, while the polystyrene characteristics at the wave number 1600.57 cm⁻¹ appeared sharper. The sound absorption test results met the ISO 11654:1997 standard for the rating level of sound absorption coefficient in materials, achieving Class D and C sound absorption with an αₙₓ value ranging from 0.328 to 0.793.

The Development of an IoT-Based Palm Solid Waste Counting System for Empty Fruit Bunches in the Palm Oil Industry Siregar, Emil Salim Parhimpunan; Mirnandaulia, Meutia; Hutajulu, Poltak Evencus; Hidayani, Tengku Rachmi; Marbun, New Vita Mey Dessty; Rachmiadji, Irwan; Hikmawan, Oksya; Hariyanto, Hariyanto; Tarigan, Enda Rasilta Br.; Simanjuntak, Andreas Rumata; Falah, Miftahul; Pardede, Erwin; Donda, Donda; Sitepu, Evi Christiani
Jurnal Pengabdian kepada Masyarakat (Indonesian Journal of Community Engagement) Vol 10, No 4 (2024): December
Publisher : Direktorat Pengabdian kepada Masyarakat Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jpkm.93563

The recent application of palm empty fruit bunches as solid waste directly on soil or as organic fertilizer has enhanced palm farms. Moreover, the co-products of this palm oil mill constitute a dependable metric for assessing mill processing performance, specifically regarding quantity and weight. The quantity of palm empty fruit bunches is usually ascertained through manual counting using a hand counter during processing. The imprecision in calculating palm empty fruit bunches is a limitation of this method, as operators sometimes perform erroneous calculations, overlook quantities, and produce contradictory results for mill management. To address this issue, the sector requires enhanced execution of a monitoring and counting system methodology. The aim of this community service project is to create an empty fruit bunches count station using an IoTbased palm solid waste counting system for use in palm mills. The Ministry of Industry - Politeknik Teknologi Kimia Industri (PTKI) Medan will engage in and oversee the advancement of Industry 4.0 within the industrial sector. The initiative was executed at Tanah Gambus Estate in Batubara Regency, North Sumatra. Assistance was provided by a palm mill partner associated with PT. Socfin Indonesia. The implementation of the empty fruit bunches palm oil counting system was conducted efficiently, facilitating optimal operations, real–time online monitoring, uninterrupted functionality exceeding 24 hours daily, swift assessment of the empty fruit bunches volume, immediate identification of traditional counting inaccuracies by operators and management, and its station provides benefits to the palm industry.

ISOLASI DAN INDENTIFIKASI BAKTERI LIPOLITIK PADA GLYCERINE PITCH DARI LIMBAH INDUSTRI OLEOKIMIA Saragih, Gimelliya; Hutajulu, Poltak Evencus; Fernandez, Benny Rio; Wahyuni, Sry; Fadhillah, Dinda Rizka; Abdillah, Abdillah; Fatiah, Rhaudatul
CHEDS: Journal of Chemistry, Education, and Science Vol 8, No 2 (2024)
Publisher : Universitas Islam Sumatera Utara

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30743/cheds.v8i2.10184

Tujuan penelitian ini adalah untuk mengisolasi dan mengidentifikasi bakteri lipolitik pada pitch gliserin limbah industri oleokimia. Sampel pitch gliserin diambil, dimasukkan dan dicampur ke dalam larutan NaCl 98%, kemudian pitch gliserin di dalam bellyer kemudian diusap secara steril ke dalam media Brain Heart Infusion (BHI), kemudian dimasukkan ke dalam inkubator shaker dengan kecepatan 200 rpm dan diinkubasi selama 24 jam, kemudian ditanam pada media agar dengan menggunakan spread plate, kemudian media diinkubasi kembali selama 24 jam pada suhu 370C. Koloni yang tumbuh pada media dihitung jumlah koloni bakterinya, diidentifikasi dengan pewarnaan gram dan uji biokimia. Hasil penelitian menunjukkan rata-rata pertumbuhan koloni bakteri sebesar 24 x 104 CFU/mL, hasil pewarnaan gram menunjukkan gram positif dan adanya aktivitas bakteri lipolitik pada uji biokimia.

Optimasi dan Sintesis Selulosa Dialdehid Berbasis Limbah Tandan Kosong Kelapa Sawit Sitinjak, Elvri Melliaty; Masmur, Indra; Shuwanto, Hardy; Dina, Sari Farah; Hutajulu, Poltak Evencus; Saragih, Gimelliya; Siahaan, Immanuel; Damanik, Fadhila Natania; Doloksaribu, Rahel Argana
Jurnal Teknik Kimia USU Vol. 14 No. 2 (2025): Jurnal Teknik Kimia USU
Publisher : Talenta Publisher (Universitas Sumatera Utara)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jtk.v14i2.20686

Empty Fruit Bunches of Oil Palm (EFB) represent one of the most problematic biomass wastes in Indonesia due to their massive volume, inefficient management, and underutilization of their chemical potential, leading to significant environmental, economic, and technical impacts. The degradation or processing of such large-scale waste generally requires a long period of time. This study focuses on converting the cellulose content in EFB into dialdehyde cellulose (DAC), which can be applied as a wet strength agent. The aim is to reduce EFB waste by isolating cellulose from EFB biomass and subsequently converting it into DAC, which can be utilized as a wet strength additive in paper or tissue products. The oxidation of EFB cellulose into DAC was optimized using sodium periodate (NaIO₄) as the oxidizing agent, with varying reaction times of 3, 6, and 9 hours. The synthesized DAC was qualitatively analyzed using the Fehling’s test and solubility observations, followed by functional group identification via FTIR and morphological characterization using SEM. Among the samples, DAC-6 exhibited the most optimal characteristics, with a degree of oxidation reaching 82.1% and a carbonyl content of 52.8%. FTIR analysis confirmed the presence of carbonyl functional groups in all DAC samples, indicating successful oxidation of hydroxyl groups in cellulose. DAC-6 showed the most prominent carbonyl absorption peak at a wavenumber of 1748 cm⁻¹.

Optimasi dan Sintesis Selulosa Dialdehid Berbasis Limbah Tandan Kosong Kelapa Sawit Sitinjak, Elvri Melliaty; Masmur, Indra; Shuwanto, Hardy; Dina, Sari Farah; Hutajulu, Poltak Evencus; Saragih, Gimelliya; Siahaan, Immanuel; Damanik, Fadhila Natania; Doloksaribu, Rahel Argana
Jurnal Teknik Kimia USU Vol. 14 No. 2 (2025): Jurnal Teknik Kimia USU
Publisher : Talenta Publisher (Universitas Sumatera Utara)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jtk.v14i2.20686

Empty Fruit Bunches of Oil Palm (EFB) represent one of the most problematic biomass wastes in Indonesia due to their massive volume, inefficient management, and underutilization of their chemical potential, leading to significant environmental, economic, and technical impacts. The degradation or processing of such large-scale waste generally requires a long period of time. This study focuses on converting the cellulose content in EFB into dialdehyde cellulose (DAC), which can be applied as a wet strength agent. The aim is to reduce EFB waste by isolating cellulose from EFB biomass and subsequently converting it into DAC, which can be utilized as a wet strength additive in paper or tissue products. The oxidation of EFB cellulose into DAC was optimized using sodium periodate (NaIO₄) as the oxidizing agent, with varying reaction times of 3, 6, and 9 hours. The synthesized DAC was qualitatively analyzed using the Fehling’s test and solubility observations, followed by functional group identification via FTIR and morphological characterization using SEM. Among the samples, DAC-6 exhibited the most optimal characteristics, with a degree of oxidation reaching 82.1% and a carbonyl content of 52.8%. FTIR analysis confirmed the presence of carbonyl functional groups in all DAC samples, indicating successful oxidation of hydroxyl groups in cellulose. DAC-6 showed the most prominent carbonyl absorption peak at a wavenumber of 1748 cm⁻¹.

Karakteristik Komposit Polimer dengan Matriks Polistirena dan Bahan Pengisi dari Berbagar Limbah Pabrik Kelapa Sawit Hidayani, Tengku Rachmi; Hutajulu, Poltak Evencus; Marbun, New Vita Mey Destty; Pardede, Erwin; Paramitha, Ratih; Nasution, Reni Silvia
REACTOR: Journal of Research on Chemistry and Engineering Vol. 5 No. 1 (2024)
Publisher : Politeknik ATI Padang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.52759/reactor.v5i1.115

The first stage of this research was to make polystyrene grafted with maleic anhydride for making the couping agent with other filling compound. In the second stage, the polystyrene matrix grafted with maleic anhydride was combined with filler material derived from palm oil mill waste using the dry mixing method with an internal mixer. Among several variables tested, the optimum composition of the polymer composite was found to be Polystyrene grafted with maleic anhydride: sludge: boiler ash in a ratio of 60:25:15. This composition exhibited a Young's modulus of 856.752 MPa, a tensile strength of 6.057 MPa, and an elongation at break of 0.775%. Differential Scanning Calorimetry (DSC) testing revealed a glass transition temperature of 403.22°C, a crystallization temperature of 426.39°C, and a cross-linking indication temperature of 478.64°C. Scanning Electron Microscopy (SEM) tests showed an even distribution of the material. Fourier-transform infrared (FT-IR) spectroscopy indicated a decrease in absorption peaks at 3024.94 cm⁻¹ and 3025.15 cm⁻¹, while the polystyrene characteristics at the wave number 1600.57 cm⁻¹ appeared sharper. The sound absorption test results met the ISO 11654:1997 standard for the rating level of sound absorption coefficient in materials, achieving Class D and C sound absorption with an αₙₓ value ranging from 0.328 to 0.793.

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