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All Journal Jurnal Kimia Mulawarman Abdimas Talenta : Jurnal Pengabdian Kepada Masyarakat Indonesian Journal of Chemistry Edumaspul: Jurnal Pendidikan Journal Economy And Currency Study (JECS) Djtechno: Jurnal Teknologi Informasi JOURNAL OF CHEMICAL NATURAL RESOURCES (JCNaR)

Amir Hamzah Siregar, Amir Hamzah

Department Of Chemistry, Faculty Of Mathematics And Natural Sciences, Universitas Sumatera Utara, Medan, 20155, Indonesia

Author-ID : 565072

Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Economics, Econometrics & Finance Education Languange, Linguistic, Communication & Media Law, Crime, Criminology & Criminal Justice Materials Science & Nanotechnology Social Sciences Other

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Pengaruh Kualitas Produk, Harga, Cita Rasa Dan Promosi Terhadap Kepuasan Konsumen Di Rumah Makan Mbak Siti Amir Hamzah Siregar, Susana, Zuriani Ritonga, Desmawati Hasibuan, Elvina
Journal Economy and Currency Study (JECS) Vol. 3 No. 1 (2021)
Publisher : Pusdikra Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.51178/jecs.v3i1.131

The purpose of this study was to determine the effect of product quality, price, taste and promotion on consumer satisfaction at Mbak Siti's restaurant in Sosopan Village, Kotapinang District, Labuhanbatu Selatan Regency. The sample in this study amounted to 30 people. The analytical method used is descriptive analysis, classical assumption test, multiple linear regression analysis, t test, f test, and coefficient of determination and this data is processed using the IBM SPSS Statistics 21 program. Hypothesis test results show that partially the product (X1) has a positive and significant effect on consumer satisfaction, this can be seen from the tcount value for product quality is tcount 0.009> ttable 2.05954, with a significant value of 0.993 <0.05. Hagra (X2) has a positive and significant effect on consumer satisfaction, this can be seen from the tcount value for price is tcount 2.273> ttable 2.05954, with a significant value of 0.32 <0.05. Taste (X3) has a positive and significant effect on consumer satisfaction, this can be seen from the tcount value for taste is tcount 0.541> ttable 2.05954, with a significant value of 0.593 <0.05. Promotion (X4) has a positive and significant effect on customer satisfaction, this can be seen from the tcount value for promotion is tcount 6.794> ttable 2.05954, with a significant value of 0.000 <0.05. The value of Ftable in the 4: 26 distribution is 2.74, so based on table 4.14 it can be seen that the Fcount value is 36.656> 2.70, and a significant value is 0.000 <0.05, this shows that simultaneously the Independent Variable has a positive and significant effect on the Dependent Variable.

PENGARUH PENAMBAHAN INISIATOR DIKUMIL PEROKSIDA DAN DIVINILBENZENA SEBAGAI CROSLINK PADA KOMPATIBILITAS RASIO CAMPURAN POLIETILENA DAN KARET ALAM SIR 3L Amir Hamzah Siregar
JURNAL KIMIA MULAWARMAN Vol 8 No 1 (2010)
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

Show Abstract | Download Original | Original Source | Check in Google Scholar

The research about the influence of adding initiator dicumyl peroxide and divinylbenzene as crosslink agent on the compatibility blending rasio polyethylene and natural rubber SIR 3L has been carried out. Blending is done in two steps, the first step was without the addition of divinylbenzene, polyethylene/natural rubber SIR 3L/dicumyl peroxide (w/w) 50 g : 50 g : 1phr, 2phr, and 3phr. The second step was by the addition of divinylbenzene, polyethylene/natural rubber SIR 3L/divinylbenzene/dicumyl peroxide (w/w) 50 g : 50 g : 1phr :1phr, 2phr : 1phr, 3phr : 1phr, 1phr : 2 phr, 2phr : 2phr, 3phr : 2phr, 1phr : 3phr, 2phr : 3phr, dan 3phr : 3phr. To determine the quality of yielded composites, the tensile test analysis was done, obtained the increasing concentration without divinylbenzene, maximum at variation of concentration polyethylene/natural rubber SIR 3L/dicumyl peroxide is 2 phr is tensile strength and elasticity was 2.20 kgf/mm2 and 12.29%, and by addition of divinylbenzene obtained the increasing maximum at variation of concentration polyethylene/natural rubber SIR 3L/divinylbenzene/dicumyl peroxide 3phr : 2phr, the tensile strength and elasticity was 3.31 kgf/mm2 and 28.99%. From the SEM analysis result was obtained that the addition of divinylbenzene could improved the composite’s surface so that become more flatten and homogeneous. From the functional group analysis FT-IR showed that the mixture of divinylbenzene and polyethylene/natural rubber SIR 3L/dicumyl peroxide were just physical interaction. Keyword: peroxside, Divinyl benzene, Poly Ethylene, Natural rubber (SIR 3 L) Blending

Preparation of Biodegradable and Low-Cost Lignin-Based PVOH Carbon Fibers Prepared by Electrospinning Amir Hamzah Siregar; Aditia Warman; Mahyuni Harahap; Grace Nainggolan; Dellyansyah Dellyansyah; Saharman Gea
Indonesian Journal of Chemistry Vol 21, No 6 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.66606

A polyvinyl alcohol (PVOH)/lignin nanofiber was prepared by the electrospinning method as a precursor for biodegradable and low-cost carbon fibers. PVOH 15% was dissolved in water, and various concentration of lignin (5, 10, 15, 20, and 25%) was added. The presence of lignin in PVOH solution increased the viscosity and conductivity. From SEM analysis, PVOH solution produced smooth fiber, whereas the addition of lignin produced fibers in bead forms. The presence of lignin above 20% in PVOH did not produce spun-fiber. FTIR analysis confirmed that lignin was able to form hydrogen bonds with PVOH. TGA analysis showed that PVOH/lignin nanofibers had the highest residual mass, i.e., 40% at 600 °C. The morphology of the carbon fibers showed flake forms with many pores and had 58.07% carbon content.

IMPLEMENTASI METODE AGILE DALAM PENGEMBANGAN APLIKASI ABSENSI BERBASIS QRCODE PADA SMP NEGERI 7 PERCUT SEI TUAN Tinambunan, Medi Hermanto; Wahyuni, Sri; Yasir, Amru; Simanjuntak, Marthin Yohannes; Siregar, Amir Hamzah
Djtechno: Jurnal Teknologi Informasi Vol 5, No 2 (2024): Agustus
Publisher : Universitas Dharmawangsa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.46576/djtechno.v5i2.4812

Perkembangan teknologi saat ini sangat cepat, hampir seluruh elemen pekerjaan sudah menggunakan teknologi, hal ini juga yang menjadi perhatian penting oleh kepala sekolah SMP Negeri 7 Percut Sei Tuan, tentunya sangat dibutuhkan sebuah sistem absensi yang dapat memberikan informasi dan rekapitulasi data dengan cepat, saat ini SMP Negeri 7 Percut Sei Tuan hanya menggunakan absensi secara manual, yang dimaksud dengan manual adalah menggunakan cetakan absensi dan melakukan tanda tangan langsung pada cetakan dan guru memanggil nama siswa, hal ini tentunya memakan waktu yang lama serta tidak efisien dalam menjalankan proses belajar mengajar. Berdasarkan informasi yang didapatkan dari wawancara dengan para guru, dibutuhkan waktu sekitar 10 sampai dengan 20 menit hanya untuk melakukan absensi sehingga waktu untuk pembelajaran terpotong cukup banyak. Berdasarkan permasalahan tersebut perlu dilakukan penyelesaian terkait waktu yang lumayan banyak termakan oleh absensi, salah satu cara yang dapat dilakukan adalah dengan membangun sebuah aplikasi dengan menerapkan metode Agile Software Development yang dapat membantu siswa dan guru untuk melakukan absensi dengan cepat, cukup hanya dengan guru mengingatkan kembali siswa untuk melakukan absensi dengan aplikasi absensi berbasis qrcode pada saat pembelajaran berakhir atau sebelum mata pelajaran terakhir selesai. Saat pengujian sistem tentunya sangat membantu para guru dan orangtua dalam melakukan pemantauan kehadiran siswa disekolah, karena fitur aplikasi ini dapat memberikan informasi melalui email ketika siswa melakukan absensi disekolah, sehingga orang tua dapat mengetahui apakah anak mereka sudah hadir disekolah. Berdasarkan hasil pengujian blackbox didapatkan tingkat kepuasan pengguna baik orangtua dan guru sangat terbantu dalam pemantuan absensi serta memberikan penilaian positif.

Exploring the Effect of Ethylenediamine Concentration on the Optical Properties of Carbon Dots Synthesized from Candlenut Shell Biomass Marpongahtun, Marpongahtun; Safhura, Tjut Siti; Siregar, Amir Hamzah
Journal of Chemical Natural Resources Vol. 7 No. 1 (2025): Journal of Chemical Natural Resources (JCNaR)
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jcnar.v7i1.20639

Carbon dots are fluorescent nanomaterials with a size below 10 nm, known for their good optical properties, including fluorescence emission and biocompatibility which are very suitable for various applications, such as bioimaging, sensors and optoelectronics. This research aims to synthesize CDs and NCDs from candlenut shells as a biomass source using the hydrothermal method at 230°C for 6 hours with the addition of ethylenediamine (EDA) as a nitrogen dopant at concentrations of 4%, 8% and 12% (v/v). The study also evaluates the effect of varying EDA concentrations on the optical properties of CDs and NCDs. Based on the results, under 365 nm UV irradiation, all samples showed bluish green fluorescence. The results of UV-Vis analysis showed an absorption peak at a wavelength of 271 nm for CDs and additional absorption peaks at 274 nm and 324 nm for NCDs, corresponding to the π–π* and n–π* transitions, respectively. Increasing EDA concentration is associated with a gradual decrease in the absorption intensity of CDs and NCDs. The photoluminescence results showed the CDs emission peak at 494 nm with a quantum yield (QY) of 18% and the strongest fluorescence at 498 nm for NCDs 8% with the highest QY of 27%. The results of FTIR analysis showed -OH, C=O and C=N functional groups in all samples and additional -NH functional groups in the NCDs, indicating successful nitrogen incorporation.

Shorting And Drying Technology Unit For Improving The Effectiveness Of Black Onion Process Sebayang, Kerista; Siregar, Amir Hamzah; Sianturi, Herty Afrina; Mirsan, Erni
ABDIMAS TALENTA: Jurnal Pengabdian Kepada Masyarakat Vol. 6 No. 1 (2021): ABDIMAS TALENTA : Jurnal Pengabdian Kepada Masyarakat
Publisher : Talenta Publisher

In 2016, the development of Gempar Tunggal Micro Small and Medium Enterprises (MSMEs) that involved in the processing of black onions began. The raw materials are obtained from the Medan City market center, but sometimes it also come from Brebes and Semarang. The goods manufacture that resulted are sold to Aceh, Kalimantan and Sulawesi. However, because it was a home industry, the manufacturing system that was developed still very simple. Therefore, some weakness were identified, in particular the percentage of damaged or defective finished goods reaching 25 percent before its sold, various levels of maturity and work processes and supervision that drained attention and energy. In addition, the cost of using electricity is also high. It was found from the literature study by the Abdimas team of USU that there are 3 parameters that affect the processing of onions, namely garlic which is sensitive to temperature, humidity and exposure period of temperature and humidity. Often, due to the unequal size of the raw onion amount, the maturity of the onions is not homogenous distributed made the bigger the raw material of the onion impacted the faster it will ripen. Another problem that found during manufacturing process is the water vapor was not completely evaporated from the furnace. Basic technology that was developed by Abdimas USU team, namely the manual gravity onion sorting and drying unit was already used by Partners in the production process. As the result, it was successfully reducing broken onions. Lastly, homogenous maturity due to dividing process the onions by scale obtained.

Characterisation of Sheet Masks with the Addition of Kemuning Leaf Extract (Murraya paniculata L.) Rahmadi, Azri; Nasution, Emma Zaidar; Siregar, Amir Hamzah; Hardiyanti, Rini
Edumaspul: Jurnal Pendidikan Vol 7 No 2 (2023): Edumaspul: Jurnal Pendidikan
Publisher : Universitas Muhammadiyah Enrekang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33487/edumaspul.v7i2.6692

Research has been conducted on the use of kemuning leaves (murraya paniculate L.) in making sheet masks with formulations of kemuning leaf extract, chitosan, tapioca flour, and glycerin as facial smoothers. The results of the tensile strength test of sheet masks with preparations show that the tensile strength results of mask preparations without kemuning leaves are greater than the tensile strength using kemuning leaf extract and the results of the FTR test there is an absorption of wavenumber 3272.6 cm-1 -OH or –NH group, absorption at wavenumber 1640 cm-1 shows the presence of a C=O group meaning that in the process of making leaf sheet masks there is no chemical reaction, but only physical interaction. The results of the texture organoleptic test on the F5 sample are more dominantly preferred, the F0 sample is preferred in terms of color, and the F0 sample is preferred in terms of aroma, while in terms of general preference F0 is preferred by panelists. The pH test results on the six samples obtained pH results ranging from 6.12-6.29 categories are still safe to use marked by the pH value of cosmetic products allowed according to SNI ranging between 4.5-8.0. The antibacterial test results in the very strong category. The results of the antioxidant test are very strong and the results of measuring specific gravity show that the addition of kemuning leaf extract does not greatly affect the specific weight of a mask product. So that the use of kemuning leaves as a facial smoother is safe to use and has significant benefits.

Fabrication of Biodegraded Composite from Polypropylene, Polypropylene Grafted Maleic Anhydride, and Chempedak Seed (Artocarpus integer) Starch Nasution, Darwin Yunus; Jumirah; Siregar, Amir Hamzah
Journal of Chemical Natural Resources Vol. 3 No. 2 (2021): Journal of Chemical Natural Resources
Publisher : Talenta Publisher

Fabrication of biodegraded composite from polypropylene, polypropylene grafted maleic anhydride, and chempedak seed (Artocarpus integer) starch has been conducted. The stages were prepared starch of Cempedak seed, grafting process of maleic anhydride on polypropylene, and fabrication of composite with a composition ratio of PP: PP-g-MA: starch of chempedak seed (9.5:0.5:0.1)g, (9.5:0.5:0.2)g, (9.5:0.5:0.3)g, (9.5:0.5:0.4)g, (9.5:0.5:0.5) g, and PP: starch of chempedak seed (10:2)g. The composites obtained were characterized using tensile strength and elongation testing, surface morphology analysis by SEM, analysis in nature with the ability to decompose by biodegradable test, and functional groups analysis by FTIR spectroscopy. The results showed that the biodegradable composites have the best properties in the ratio of PP: PP-g-MA: starch of chempedak seed (9.5:0.5:0.1)g with the test results of tensile strength was 28.743 N/m2, and also the SEM results show that flat surface and improved homogeneity, and strong group interactions as well as having good biodegradable properties.

Characterization of Biodegradable Composites from Polypropylene, Polypropylene Grafted Maleic Anhydride, and Durian Seed Starch Nasution, Darwin Yunus; Fitri, Rizka Meilia; Siregar, Amir Hamzah
Journal of Chemical Natural Resources Vol. 4 No. 1 (2022): Journal of Chemical Natural Resources
Publisher : Talenta Publisher

The characterization of biodegradable composite from durian seed starch that is mixed polypropylene, and polypropylene grafted maleic anhydride has been done. The stages of this preparation were, the first had prepared durian seed starch, the second had the process of grafting maleic anhydride into polypropylene and the third had made of composite with the composition of PP:PP-g-MA: DSS (7:0.5:0.2); (7:0.5:0.3); (7:0.5:0.4); (7:0.5:0.5); (7:0.5:0.6) (w/w). The biodegradable composites obtained were characterized by tensile strength, surface morphology analysis by SEM, differential thermal analysis (DTA), analysis in nature with the ability to decompose biodegradable test, and functional groups analysis by FTIR spectroscopy. The results showed that the biodegradable composites have the best properties in the ratio of PP:PP-g-MA: DSS was (7:0.5:0.5) (w/w) with the test results of tensile stress is 12.556 N/m2, and the elongation is 8.600%, the images on a few flat surfaces and improved homogeneity, temperature change, and strong group interactions as well as having good biodegradable properties.

Utilization of Coconut Shells Activated Charcoal in Making Solid Soap from Used Cooking Oil Siregar, Amir Hamzah; Harahap, Ardina
Journal of Chemical Natural Resources Vol. 5 No. 2 (2023): Journal of Chemical Natural Resources
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32734/jcnar.v5i2.13857

Research on the utilization of coconut shell activated charcoal in making solid soap from used cooking oil by adding variations in the concentration of coconut shell activated charcoal by 3%, 5%, 10% and without purification. So, several parameters can be determined to test the quality of used cooking oil, namely PV, free fatty acid (FFA), color, moisture content, and odor based on SNI 3741: 2013. The parameter value of used cooking oil without purification on PV is 15,1607 mekO2/ kg. FFA, which is 0.8244 mgKOH / g. Water content is 0.1321% b / b. Smell that is not normal. The resulting color is 10.28 red / 87.00 yellow. Value The parameters of the quality of cooking oil produced from the treatment process after the addition of a variation of coconut shell activated charcoal by 10% can reduce the PV of 5.5247 mecO2/kg. FFA which is 0.2817 mgKOH / g. Water content is 0.0798% b / b. The smell becomes normal. The resulting color is 3.40 red / 35.00 yellow. It can be concluded that the concentration of the addition of coconut shell activated charcoal, which is optimal in the processing process, is by adding coconut shell activated charcoal by 10% in used cooking oil to meet the cooking oil quality standards according to SNI 3741: 2013. Solid soap-free fatty acids were not detected in the study of making solid soap from purified cooking oil. The soap solution was pink when the testing process was titrated with KOH solution 0.1 N. This is presumably because the fatty acids in used cooking oil have reacted all with NaOH so that the free fatty acids cannot be measured.

Co-Authors Aditia Warman Darwin Yunus Nasution Dellyansyah Dellyansyah Fitri, Rizka Meilia Grace Nainggolan Harahap, Ardina Jumirah Kerista Sebayang Mahyuni Harahap Marpongahtun, Marpongahtun Medi Hermanto Tinambunan Mirsan, Erni Nasution, Emma Zaidar Rahmadi, Azri Rini Hardiyanti Rokhmayanti, Etika Safhura, Tjut Siti Saharman Gea Sianturi, Herty Afrina Simanjuntak, Marthin Yohannes Sri Wahyuni Yasir, Amru

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