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All Journal Proceedings of Annual International Conference Syiah Kuala University - Life Sciences & Engineering Chapter JURNAL PENELITIAN SAINTIKA Elkawnie Jurnal Kimia Mulawarman Padjadjaran Journal of Dentistry Lantanida Journal Abdimas Talenta : Jurnal Pengabdian Kepada Masyarakat Jurnal Pendidikan Kimia (JPKim) Indonesian Journal of Chemistry Chemistry Indonesian Journal of Chemical Research Jurnal Ilmu Fisika Journal of Saintech Transfer Bioscientia Medicina : Journal of Biomedicine and Translational Research Denta: Jurnal Kedokteran Gigi JOURNAL OF CHEMICAL NATURAL RESOURCES (JCNaR) Jurnal Natural Jurnal Solusi Masyarakat (JSM) Jurnal Akademika Kimia Holistik Jurnal Kesehatan

Saharman Gea

Department Of Chemistry, Faculty Of Mathematics And Natural Sciences, Universitas Sumatera Utara

Author-ID : 268936

Agriculture, Biological Sciences & Forestry Astronomy Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Dentistry Earth & Planetary Sciences Economics, Econometrics & Finance Education Energy Engineering Environmental Science Health Professions Immunology & microbiology Languange, Linguistic, Communication & Media Law, Crime, Criminology & Criminal Justice Materials Science & Nanotechnology Medicine & Pharmacology Neuroscience Nursing Physics Public Health Social Sciences Other

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Karakterisasi Silikon dari Sekam Padi Terdoping dengan Kobalt: Analisis Struktur dan Sifat Magnetoelektrik Kurniawan, Rizky; Andriayani, Andriayani; Gea, Saharman; Kurniawan, Hadi
Jurnal Ilmu Fisika Vol 16 No 2 (2024): September 2024
Publisher : Jurusan Fisika FMIPA Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jif.16.2.97-106.2024

The development of Si-based materials has attracted increasing attention, particularly for application in semiconductors, batteries, sensors, and optical technology. Silicon has abundant availability, high energy storage capacity, and low work potential. However, it faces compatibility challenges due to its low electrical conductivity and extremely small magnetic susceptibility. This research aimed to investigate the influence of Co dopants on the structure, morphology, electrical conductivity, and magnetic susceptibility of silicon. Silicon was synthesized using the magnesiothermic reduction method, and silicon was modified with Co metal dopants at 0.1% and 0.5% concentrations through the impregnation method. XRD analysis results showed that Si, 0.1% Co/Si, and 0.5% Co/Si exhibit silicon diffraction patterns at 2θ = 28.42º; 47.28º; 56.11º; 69.13º; and 76.36º. The morphology of Si and Co/Si revealed a rough, uneven, and porous surface with particles appearing spherical. Electrical conductivity increases with Co concentration: Si = 1223 µS/cm, 0.1% Co/Si= 1376 µS/cm, and 0.5% Co/Si= 1529 µS/cm. Magnetic susceptibility measurements indicated that Si, 0.1% Co/Si, and 0.5% Co/Si are paramagnetic at a range of 1.18 x10-6 to 1.25 x10-5 SI. These characterization results confirmed that the modification with Co dopants can enhance the magnetoelectric properties of silicon.

Briquettes manufacturing: mechanisation of briquette productions at SME santan coco Gea, Saharman; Diana, Diana Alemin Barus; Elisa, Elisa Julianti; Aditia, Aditia Warman
ABDIMAS TALENTA: Jurnal Pengabdian Kepada Masyarakat Vol. 4 No. 2 (2019): ABDIMAS TALENTA: Jurnal Pengabdian Kepada Masyarakat
Publisher : Talenta Publisher

The fabrication of briquettes is required to be introduced extensively to society in order to provide additional economic value for charcoal crafters to increase their income. The SME Santan Coco as partnership enterprise of community service under supervising of Universitas Sumatera Utara has been producing briquettes since 2018 resulted from waste of coconut milk production. However, the methodology of producing briquettes can be considered to be insufficient. The production is started by the addition of charcoal powder with adhesives compounds which is followed manual stirring. The moulding process involves by using a lever utilizing body-weight, which produces two briquettes. The charcoal powder is obtained by manually crushing the charcoal, so that its granular size is not uniform. The briquette production is very slow due to the equipment used produces two briquettes. On the other hand, the preparation of raw materials into the moulding equipment requires longer time, as well as removing the ready-to-use briquette from the mould. The prepared mixture must be printed immediately, so that the adhesive is not dried. The final product fabricated by the partner shows that the granular sizes are different which affects the density parameters, productions volume accounted for 50 kg per day. Therefore, a mechanism of briquette production is proposed and introduced to the partner, which involves from charcoal breaking, mixing and molding briquettes. A charcoal crusher uses a hammer mill system with 12 eyes, equipped with a filter. The mixing of adhesive substances utilizes a ribbon blade mixing system, while the briquette printing is designed with a screw system. After being implemented, a very significant increase in production up to 500 kg of wet briquettes per day with higher density and more uniform as well as neater granular size has been obtained.

Scientific Writing Coaching Class for Teachers in Sibolga City gea, saharman; Aththorick, T. Alief; Lenny, Sovia; Sihombing, Yuan Alfinsyah; Pasaribu, Khatarina Meldawati; Piliang, Averrous Fazlurrahman
ABDIMAS TALENTA: Jurnal Pengabdian Kepada Masyarakat Vol. 6 No. 1 (2021): ABDIMAS TALENTA : Jurnal Pengabdian Kepada Masyarakat
Publisher : Talenta Publisher

Referring to Ministerial Regulation of PAN-RB No. 16 of 2009 on Teacher Functional Status and Credit Score, it is clearly mentioned that one of the key components to apply teacher promotion is scientific writing (KTI). However, in fact, it was found that many teachers were independently constrained, especially in Sibolga City. As a result, the chance to get a higher rank and to be placed would be hampered. In addition, even some teachers are caught up in taking shortcuts by using the third part services to prepare their scientific writing, which of course, are not acceptable in publication ethics and academic values. In line with the results of preliminary observations made by the team, it was noticed that the teachers writing ability can be improved by providing them writing coaching class, including explanations and even training materials that need to be used in scientific writing. This writing coaching class is intended to provide teachers an opportunity to develop their skills, especially skill to write down scientific papers. Writing coaching class will be done by encouraging teachers to compose their ideas, formulating their problems, obtaining references sources, providing consultation rooms, implementing ethics and scientific publishing regulation, and selecting places where scientific papers will be published.

Teacher Upgrading Skill in Preparing Materials and Examination Based on Images in Sibolga City Andriayani, Andriayani; Zuhra, Cut Fatimah; Maghfirah, Awan; Yanti, Maulida; Gea, Saharman; Pasaribu, Khatarina Meldawati; Piliang, Averrous Fazlurrahman
ABDIMAS TALENTA: Jurnal Pengabdian Kepada Masyarakat Vol. 5 No. 2 (2020): ABDIMAS TALENTA : Jurnal Pengabdian Kepada Masyarakat
Publisher : Talenta Publisher

There are 61 primary/ibtidaiyah schools, 18 junior high schools, and 18 senior high schools in the city of Sibolga, which is located in Teluk Tapian Nauli, with a total number of teachers of about 2000. This is in line with the vision of Sibolga city (2016-2021) in order to create a stable, advanced, and successful Sibolga City by producing highly competitive quality human beings in order to create a harmonious, peaceful, secure and unified society. As mentioned above, one of its mission points is to prepare human resources (HR) that have integrity, reliable, competitive, expert in science and technology so that they able to compete in the global job market. As the education stakeholder, Sibolga Education and Culture Official has plan many outstanding work programs such as made a collaboration in partnership with the Universitas Sumatera Utara community service team. As a result, based on field observations and discussions, it was known that one of the obstacle that facing by the teachers in Sibolga is not being able to provide teaching materials and also picture-based examination questions as contained in the question grid. Currently, there are several technology-driven applications that can be used to make images or graphics creating process easier. Two of them are, GeoGebra Classic that used to create graphics and images in mathematics and Chemdraw that used to create structure images that related to chemistry. In addition word optimization training was also conducted to optimize teacher on preparing teaching materials with Ms. word.

Improvement of Research Proposal Writing Skills for PSDKU USU Lecturers in North Nias Gea, Saharman; Rahmawaty; Iskandar Zulkarnain
ABDIMAS TALENTA: Jurnal Pengabdian Kepada Masyarakat Vol. 10 No. 1 (2025): ABDIMAS TALENTA: Jurnal Pengabdian Kepada Masyarakat
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/abdimastalenta.v10i1.20092

The Tridharma of Higher Education mandates that higher education institutions conduct education, research, and community service (Article 1, Clause 9, Law No. 12 of 2012 on Higher Education). Research is a methodical endeavor that adheres to scientific principles and methodologies to collect information, facts, and explanations pertinent to the comprehension and/or examination of a field within science and technology. The USU Abdimas Team's community service is to consistently educate and support academics at PSDKU USU Nias Utara, hence addressing the research aspect of the Tridharma of Higher Education. The given materials are: (1). The resources seek to elucidate research concepts and offer guidance on building a well-structured proposal in accordance with scientific standards and research ethics. Two. The procedure for formulating a suitable proposal grounded in scientific principles and research ethics is addressed in the section. Three. Investigating local potential to be elevated as research topics, and (4). There are techniques for forging links in research initiatives. The aforementioned four materials are considered particularly advantageous for cultivating a research culture among academics at PSDKU USU Nias Utara. This commences with improving their expertise in research planning, hence facilitating the execution of the SDGs point 4 initiative, Quality Education. Quality Education is a fundamental component of the Sustainable Development Goals (SDGs). Due to the time limitations of in-person training, mentoring has transitioned online, with the anticipation that the training participants will generate many high-quality research proposal drafts.

Synthesis and characterization nitrogen-doped carbon dots from candlenut shells using hydrothermal and solvothermal methods Riska, Riska; Marpongahtun, Marpongahtun; Gea, Saharman
Jurnal Pendidikan Kimia Vol. 16 No. 1 (2024): April
Publisher : Pascasarjana Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/jpkim.v16i1.56957

Candlenut shells can be utilized as precursors for Carbon Dots (CDs) since new nanoscale materials have been proven using lignin, cellulose, hemicellulose, and carbon present in candlenut shells. A carbon substance smaller than 10 nm in size, CDs have special optical properties. This research focuses on the synthesis of CDs and Nitrogen Carbon Dot (NCDs) from hazelnut shell using urea passivation agent by hydrothermal and solvothermal methods, to determine the effect of solvent on the emission produced by CDs and NCDs. Hazelnut shell was carbonized at 300°C for 6 hours. The synthesis of CDs and NCDs was carried out at 220°C for 8 hours, then sonicated at 75°C for 30 minutes. The synthesis results were centrifuged at 5000 rpm for 30 minutes, filtered using Whatman No.42 filter paper. Analysis with a 365 nm UV lamp produced bluish green luminescence, brighter luminescence was shown in NCDs by solvothermal method. UV-Vis spectra showed absorbance peaks of 289-309 nm for CDs and 335-350 nm for NCDs. FTIR spectra of CDs and NCDs produced OH, CH, C=C, C=O, C-N, CO, and C-O-C functional groups. Photoluminescence analysis showed emission peaks of CDs and NCDs at 494 nm and 496 nm for hydrothermal method, for solvothermal method at 418 nm and 432 nm. CDs and NCDs with hydrothermal method showed higher intensity than with solvothermal method. The quantum yield values obtained were 11.4226% and 25.7419% and 10.2555% and 11.7473% for hydrothermal and solvothermal methods, respectively. Solvothermal method was effective for the synthesis of CDs and NCDs with brighter luminescence.

Impact of the Concentration Ethylenediamine on Optical Properties of Carbon Dots from Jengkol Peel (Archinendron pauciflorum) Prayugo, Aniza S.; Marpongahtun, Marpongahtun; Gea, Saharman
Jurnal Akademika Kimia Vol. 12 No. 1 (2023)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2023.v12.i1.pp20-25

Carbon dots (CDs) are a new member of fluorescent nano carbons that have attracted attention because of their potential applications derived from their optical, chemical, and electrical properties. CDs from jengkol peel via the solvothermal method at 200 oC for 7 h with the addition of ethylenediamine (EDA) as a heteroatom dopant have been successfully carried out. This study aims to determine the effect of concentration EDA on the optical properties of CDs for the possible reason. The results revealed that the CDs solution has fluorescence properties; that bluish-green glow can be observed under ultraviolet radiation (365 nm). The UV - Vis absorption peaks did not depend on the CDs concentration, but the absorbance intensity decreased with increasing EDA concentration. The best fluorescence properties were possessed by 10 % EDA in CDs which produced λex/λem of 370 nm/518 nm, respectively, with a quantum yield of 42 %. The FTIR spectra of all samples showed that the CDs surface had functional groups such as carboxylic acids, hydroxyl, and amines. The obtained CDs have the potential to be used as heavy metal ion detectors, bioimaging, and antibacterial agents.

Synthesis of Fluorescent Carbon Dots from Soybean Residuals Using Hydrothermal Method Ayu, Dinda G.; Gea, Saharman; Andriayani, Andriayani; Goei, Ronn
Jurnal Akademika Kimia Vol. 12 No. 2 (2023)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2023.v12.i2.pp71-77

Soybean residuals are biowaste composed of carbon chains and amine groups bounded in peptide linkages. The component was identified through FTIR analysis which showed the vibration of the diamide bond (N=C=N) at wave number 2132cm-1. Owing to the existence of these components, soybean has the potential to be used as a precursor to synthesize carbon nano-material, such as Carbon Dots (C - Dots). In this study, the synthesis of C - Dots material from soybean residuals was carried out using the facile hydrothermal method at a temperature of 200 oC for 6 hours. Afterward, the as-synthesized C - Dots were analyzed for their optical property, structure, and morphology. Based on the analysis of the UV - Vis and photoluminescent spectra, C - Dots exhibited absorbance peaks of 292 nm and 301 nm in the UV light region, and fluorescence emission peaks of 468 nm, with blue luminescence characteristics. The observation was supported by the morphological analysis using the HR - TEM, C - Dots exist in a spherical shape with an average particle size of 3.467 nm and a lattice distance of 0.363 nm. Besides, the C - Dots exhibited a good quantum yield of 28.15 %. From the results of the analysis, it is known that the synthesis of C - Dots material has been successfully carried out with particle size < 10 nm.

Study of Provision of Cellulose Nanocrystal Derived From Palm Oil Empty Fruits Bunches (EFB) Marpongahtun; Aulia, Fenny; Gea, Saharman
Journal of Chemical Natural Resources Vol. 3 No. 2 (2021): Journal of Chemical Natural Resources
Publisher : Talenta Publisher

Isolation and characterization of cellulose nanocrystal of alpha-cellulose from Empty Fruit Bunch (EFB) have been performed. Empty Fruit Bunch (EFB) was delignificated with 3.5% HNO3 and NaNO2, precipitated with17.5% NaOH, bleaching process with 10% H2O2. Nanocrystal was obtained through the hydrolysis of alpha-cellulose using 45% H2SO4. Nanocrystal surface structures cellulose was analyzed by Scanning Electron Microscopy (SEM) and the results show that the resulting cellulose Nanocrystal size was 79 nm. Analysis of thermal degradation using Thermal Gravimetric Analysis (TGA) shows that the cellulose nanocrystal was started at 160ÂºC decomposes. It shows the process of cellulose nanocrystal that isolated from alpha-cellulose has occurred.

Co-Authors . Suryati ., Julinawati Abdul Rahman, Syarifah Nur Syed Aditia Warman Aditia, Aditia Warman Agus Haryono Agus Haryono Ahmad Nasir Pulungan Amir Hamzah Siregar, Amir Hamzah Amru Daulay Andriayani APRI H SISWANTO Ariyani, Ariyani Aththorick, T. Alief Averroes Fazlur Rahman Piliang AVERROES FAZLUR RAHMAN PILIANG Ayu, Dinda G. Basuki Wirjosentono BASUKI WIRJOSENTONO Binti Awang, Khalijah Cut Fatimah Zuhra Deddi Prima Putra Dellyansyah Dellyansyah Diana Alemin Barus Diana, Diana Alemin Barus Dwi Indria Cherlina DWI SURYANTO Eddiyanto Eddiyanto EDDYANTO EDDYANTO Elis Anggeria Elisa Putri Elisa, Elisa Julianti Era Yusraini Fachry Wirathama, Syahrinal Anggi Daulay Halimatuddahliana Fenny Aulia Girsang, Ermi Goei, Ronn Grace Nainggolan Hadi Kurniawan, Hadi Hamonangan Nainggolan Harry Agusnar I Putu Mahendra ICHWANA RAMLI Junifa Layla Sihombing LIVER IMAN PUTRA ZAI Lubis, Muhammad Frassetia Lubis, Yuni Aldriani Maghfirah, Awan Mahyuni Harahap Marpongahtun Marpongahtun, Marpongahtun Mutiara Dewi Pangaribuan Nasution, Ismet Danial NONI OKTARI NUR AZIZAH Nurfajriani ., Nurfajriani Nurwijayanti Pai, Woei Wu Larry Pasaribu, Khatarina Meldawati Piliang, Averrous Fazlurrahman Prayugo, Aniza S. Rahayu Rahayu Rahmawaty Resmi Pangaribuan Riska Riska Rizky Kurniawan Rufina Pramudita Sembiring, Beby Karina F. Situmorang, Syafrizal Helmi Slamat Tarigan Sondang Pintauli Sopan Sinamo Sovia Lenny SRI RAHAYU Syafruddin Ilyas Syahrul Humaidi, Syahrul Tarigan, Almina Rospitaria Tarigan, Kerista Thamrin . Tiamina Nasution Vivi Purwandari Vivi Purwandari Wesly Hutabarat, Wesly Yanti, Maulida Yasir Arafat Hutapea yeni absah Yuan Alfinsyah Sihombing

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