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All Journal JPAP (Jurnal Penelitian Administrasi Publik) (e-Journal) Sainmatika: Jurnal Ilmiah Matematika dan Ilmu Pengetahuan Alam Risalah Fisika Makara Journal of Science
Alfarisa, Suhufa
Department of Physics, Universitas PGRI Palembang, Indonesia
Agriculture, Biological Sciences & Forestry Chemistry Decision Sciences, Operations Research & Management Mathematics Physics Other

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PEMANFAATAN MINYAK PELUMAS BEKAS UNTUK FABRIKASI BOLA KARBON MIKRO MENGGUNAKAN METODE DEPOSISI UAP KIMIA TERMAL Alfarisa, Suhufa; Abu Bakar, Suriani
Sainmatika: Jurnal Ilmiah Matematika dan Ilmu Pengetahuan Alam Sainmatika Volume 13 No. 1 Juni 2016
Publisher : Faculty of Mathematics and Natural Science, Universitas PGRI Palembang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31851/sainmatika.v13i1.961

Abstract

Carbon microspheres (C-mS) were successfully synthesized from used lube oil as the carbon source using thermal chemical vapor deposition method. The nature present of carbon content in used lube oil promoted the growth of C-mS. The oil mixed with 5,33 wt% of ferrocene catalyst was initially heated at 450 °C in the precursor furnace and then transferred into deposition furnace at 900 °C by the flow of argon carrier gas. The collected sample was then analyzed using field emission scanning electron microscope (FESEM) and micro-Raman spectroscopy. The current-voltage (IV) profile of the C-mS was also studied using four-point probe measurement. FESEM and micro-Raman analyses showed the production of high density C-mS with diameter range of 0,57 – 3,14 mm and ID/IG ratio of 0,95. Semiconductor characteristic was observed from IV measurement indicated that the C-mS synthesized from used lube oil has potential to be applied in electronic devices. This study noted that the used lube oil can be used as an economical carbon source to replace the conventional chemical precursor to produce high quality carbon material. On the other hand, it also offered a new utilization of used lube oil which can be harmful to our environment.Keywords: carbon microspheres, used lube oil, chemical vapor depositionABSTRAKBola karbon mikro berhasil disentesis dari minyak pelumas bekas sebagai sebagai sumber karbon menggunakan metode deposisi uap kimia termal. Keberadaan alami dari kandungan karbon di dalam minyak pelumas menyebabkan pertumbuhan bola karbon mikro. Pelumas yang dicampur dengan katalis ferosen dengan konsentrasi 5,33 %b mula-mula dipanaskan pada suhu 450 °C di dalam pemanas prekursor, kemudian ditranfer ke pemanas deposisi ada suhu 900 °C melalui aliran gas argon. Sampel yang terkumpul kemudian dianalisis menggunakan mikroskop elektron emisi medan (FESEM) dan spektroskopi mikro-Raman. Profil arus-tegangan (IV) dari bola karbon mikro juga dipelajari menggunakan pengukuran probe empat titik. Analisis FESEM dan mikro-Raman menunjukkan produksi bola karbon mikro dengan kerapatan tinggi dengan rentang diameter antara 0,57 – 3,14 mm dan rasio ID/IG sebesar 0,95. Karakteristik Schottky teramati dari pengukuran IV yang mengindikasikan bahwa bola karbon mikro yang disintesis dari minyak pelumas bekas memiliki potensi untuk diaplikasikan di dalam piranti elektronik. Kajian ini juga menunjukkan bahwa minyak pelumas bekas bisa dimanfaatkan sebagai sumber karbon ekonomis untuk menggantikan prekursor kimia konvensional untuk menghasilkan material karbon berkualitas tinggi. Di sisi lain, kajian ini juga menawarkan pemanfaatan baru dari minyak pelumas bekas yang bisa berbahaya bagi lingkungan. Kata kunci: bola karbon mikro, minyak pelumas bekas, deposisi uap kimia
Studi Difraksi Sinar-X Struktur Nano Seng Oksida (ZnO) Alfarisa, Suhufa; Rifai, Dwi Ahmad; Toruan, Parmin Lumban
Risalah Fisika Vol 2, No 2 (2018): Risalah Fisika ISSN 2548-9011
Publisher : Physical Society of Indonesia (PSI)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (147.34 KB) | DOI: 10.35895/rf.v2i2.114

Abstract

Abstrak – Kajian terhadap difraksi sinar-X struktur nano ZnO dengan waktu sonikasi yang berbeda telah dilakukan menggunakan metode hidrotermal-sonokimia. Variasi waktu sonikasi yang digunakan dalam kajian ini adalah 0 (tanpa sonikasi), 30, 45, dan 60 menit. Pola difraksi sinar-X diplotkan dan dibandingkan untuk mengetahui struktur, kristalinitas dan kemurnian ZnO yang dihasilkan. Estimasi ukuran kristal ZnO juga dihitung menggunakan persamaan Scherrer. Hasil penelitian menunjukkan bahwa struktur nano ZnO yang disintesis tanpa proses sonikasi memiliki kemurnian kristal yang rendah dengan ukuran kristal yang sedang berkisar dari 22,36 – 32,90 nm. Proses sonikasi telah menyebabkan kristalinitas dan kemurnian ZnO meningkat jadi lebih baik. Namun, memperpanjang waktu sonikasi hingga 45 sampai 60 menit menyebabkan membesarnya ukuran kristal ZnO. Waktu sonikasi yang paling optimal adalah 30 menit dimana mampu menghasilkan ZnO dengan kristalinitas dan kemurnian yang baik dan rentang ukuran kristal ZnO yang lebih kecil antara 22,09 – 21,97 nm.                                                                                   Kata kunci: difraksi sinar-X, struktur nano, ZnO, sonikasi, Scherrer Abstract – Research on the X-ray diffraction study of ZnO nanotructure synthesized at different sonication times has been done using hydrothermal-sonochemical method. Sonication variation times that were used in this study were 0 (without sonication), 30, 45, and 60 minutes. The X-ray diffraction patterns were plotted and compared to understand the structure, crystallinity and purity of the resulted ZnO. The estimated crystallite size of ZnO nanostructure were also calculated using Scherrer equation. The results showed that the ZnO nanostructure synthesized without sonication process has a low crystal purity and a fair crystallite size in the range of 22.36 - 32.90 nm. Sonication process has led to a better crystallinity and purity of ZnO. However, longer sonication times up to 45 to 60 minutes has caused to the larger crystal size of ZnO. The most optimum sonication time was found to be 30 minutes which resulted in a good crstallinity and purity of ZnO and smaller crystallite size in the range of 22.09 – 31.97 nm.Key words: X-ray diffraction, nanostructures, ZnO, sonication, Scherrer
Urgensi Pelaksanaan Pengawasan Kemetrologian Legal Guna Mewujudkan Kabupaten Bangka Selatan Daerah Tertib Ukur Alfarisa, Suhufa
JPAP: Jurnal Penelitian Administrasi Publik Vol 7 No 2 (2021): Jurnal Penelitian Administrasi Publik (JPAP)
Publisher : Universitas 17 Agustus 1945 Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30996/jpap.v7i2.5422

Abstract

Based on the 2014 Regional Autonomy Law, the implementation of legal metrology in the form of calibration, re-calibration and supervision is now the authority of the district/city. This study is expected to provide information related to legal metrology in general and particularly the importance of implementing metrological supervision in the regions. This research was conducted with a qualitative approach with the method of literature review and case studies in Bangka Selatan Regency. The low number of Measuring, Dosing, Weighing Equipment and Their Equipment (UTTP) and Packaged Goods (BDKT) in accordance with the provisions of the legislation is the main factor that causes the importance of this metrological supervision activity to be carried out, in addition to the low level of public understanding or knowledge regarding metrology. legal. In the end, effective metrological monitoring activities can help create an Orderly Measurement Area that is able to provide protection to consumers, especially in trade transactions.
Morphological and Structural Studiesof ZnO Micro-Nanorod Structures Synthesized Using a Low-Cost Hydrothermal Method Alfarisa, Suhufa; Toruan, Parmin Lumban; Atina, Atina; Dwandaru, Wipsar Sunu Brams; Safitri, Rika Noor
Makara Journal of Science
Publisher : UI Scholars Hub

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Abstract

Micro-nanorod structuresof zincoxide (ZnO) have been successfully synthesized via a simple and low-cost hydrothermal method. ZnO solutions with different concentrations of 0.05 and 0.1 M were prepared using zinc nitrate tetrahydrate and hexamethylenetetramine precursors. They were dissolved inaquadesand stirred before the hydrothermal process at 95 °C for 4 hours in an oven. Extensive characterizations using scanning electron microscope (SEM) and X-ray diffraction (XRD) were conductedon ZnO powder samples. SEM results showed that hexagonally shaped ZnO micro-nanorods were formed with diameters ranging from hundreds of nanometers to several micrometers. The ZnO sample synthesized at 0.05 M was observedto have a better surface morphological structurethan the 0.1 M sample. In addition, XRD measurements confirmed that samples exhibited a hexagonal crystal structure of ZnO. Moreover, the calculated crystallite sizes of ZnO using the Debye-Scherrer equation using the full-width half maxima of the XRD peaks were 25.153 nm for the 0.05 M sample and 28.707 nm for the 0.1 M sample. The most prominent growth of ZnO had 101 plane orientation or nonpolara-plane followed by nonpolar 100 m-plane and 002 polar c-plane orientations.This studyoffersa simple andlow-costroute to producehigh-quality ZnO micro-nanorods for use in various electrical and optical devices.
Density Profiles, Energy, and Oscillation Strength of a Quantum Dot in Two Dimensions with a Harmonic Oscillator External Potential using an Orbital-free Energy Functional Based on Thomas–Fermi Theory Alfarisa, Suhufa; Dwandaru, Wipsar Sunu Brams; Darmawan, Denny
Makara Journal of Science
Publisher : UI Scholars Hub

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Abstract

This research aims i) to determine the density profile and calculate the ground state energy of a quantum dot in two dimensions (2D) with a harmonic oscillator potential using orbital-free density functional theory, and ii) to understand the effect of the harmonic oscillator potential strength on the electron density profiles in the quantum dot. This study determines the total energy functional of the quantum dot that is a functional of the density that depends only on spatial variables. The total energy functional consists of three terms. The first term is the kinetic energy functional, which is the Thomas–Fermi approximation in this case. The second term is the external potential. The harmonic oscillator potential is used in this study. The last term is the electron–electron interactions described by the Coulomb interaction. The functional is formally solved to obtain the electron density as a function of spatial variables. This equation cannot be solved analytically, and thus a numerical method is used to determine the profile of the electron density. Using the electron density profiles, the ground state energy of the quantum dot in 2D can be calculated. The ground state energies obtained are 2.464, 22.26, 90.1957, 252.437, and 496.658 au for 2, 6, 12, 20, and 56 electrons, respectively. The highest electron density is localized close to the middle of the quantum dot. The density profiles decrease with the increasing distance, and the lowest density is at the edge of the quantum dot. Generally, increasing the harmonic oscillator potential strength reduces the density profiles around the center of the quantum dot.
Co-Authors Abu Bakar, Suriani Atina - Atina, Atina Denny Darmawan Parmin Lumbantoruan Rifai, Dwi Ahmad Rika Noor Safitri Safitri, Rika Noor Toruan, Parmin Lumban wipsar sunu brams dwandaru Wipsar Sunu Brams Dwandaru Wipsar Sunu Brams Dwandaru