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All Journal Indonesian Physical Review Jurnal Teori dan Aplikasi Fisika Inovasi Fisika Indonesia (IFI) Prosiding Seminar Nasional Unimus

Lydia Rohmawati

Unknown Affiliation

Author-ID : 2523376

Humanities Earth & Planetary Sciences Education Electrical & Electronics Engineering Engineering Health Professions Materials Science & Nanotechnology Nursing Physics Public Health

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Articles

Sintesis Hidroksiapatit dari Tulang Ikan Sapu-Sapu (Hypostomus plecostomus) dengan Metode Presipitasi Sri Maulidiyah Mangkuasih; Lydia Rohmawati
Jurnal Teori dan Aplikasi Fisika Vol 9, No 2 (2021): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v9i2.2818

Abstract. Fish bone contains about 62.31% CaO and 37.46% P2O5 so that it can be used as hydroxyapatite material. This composition is also contained in the bone of the broom fish (Hypostomus plecostomus) which is known from the XRF test. Therefore, the purpose of this study was to determine the phase and functional group of hydroxyapatite from broomstick fish bones. Synthesis of hydroxyapatite from broomstick fish bones using the precipitation method, namely as much as 7 grams of CaO dissolved in 100 ml of distilled water and heated at 90°C then added 100 ml of 0.6 M H3PO4 to obtain a clear solution. Then the solution was added with 1 M NaOH until it reached pH 10, allowed to stand for 24 hours and a precipitate was formed. After that, it was heated at a temperature of 900°C with a holding time variation of 5 hours and 7 hours and then cooled at room temperature. The results of this synthesis were characterized by XRD and FTIR. Based on the XRF results, the broom fish bone has a CaO content of 81.37%. The main phase of hydroxyapatite was formed optimally at a holding time of 7 hours and had a crystal size of 32.39 nm which was calculated based on the Scherrer equation. FTIR results show that hydroxyapatite consists of three main functional groups, namely phosphate , hydroxyl (OH-) and carbonate in the wave range of 4000 cm-1 – 500 cm-1. Thus, in this study, hydroxyapatite from broom fish bones was successfully synthesized. Keywords : Hydroxyapatite, CaO, broom fish bone, Precipitation.

ANALISA STRUKTUR MIKRO BAJA KARBON JIS SCM 415 PADA PROSES PACK CARBURIZING MENGGUNAKAN MEDIA ARANG AKTIF TEMPURUNG KELAPA” RIA DWI IZHYANTI; Nugrahani Primary Putri; Lydia Rohmawati
Inovasi Fisika Indonesia Vol 2 No 1 (2013)
Publisher : Jurusan Fisika FMIPA Universitas Negeri Surabaya

Abstrak Penelitian ini dilakukan untuk menganalisis pengaruh holding time melalui metode carburizing terhadap struktur mikro baja JIS SCM 415 dengan menggunakan media karbon aktif tempurung kelapa. Proses carburizing dilakukan dengan memanaskan spesimen baja pada suhu austenitnya yaitu pada suhu 850oC, 900oC dan 923oC yang kemudian di holding selama 3 jam. Proses carburizing menggunakan media arang tempurung kelapa yang sebelumnya telah diaktivasi secara kimia menggunakan H2SO4 0,5M. Karakterisasi struktur mikro spesimen baja menggunakan mikroskop optik. Hasil pengujian struktur mikro untuk raw material didominasi fasa ferit dan pada spesimen carburizing dengan holding time selama 3 jam pada suhu 923oC didominasi oleh fasa martensit. Kata Kunci : Baja JIS SCM 415, carburizing, struktur mikro. Abstract The study was conducted to analyze the effect of holding time through carburizing method to microstructure JIS SCM 415 steel using coconut shell activated carbon media. Carburizing process carried out by heating the steel specimen at a temperature that is at a temperature of 850oC austenitnya, 900oC and 923oC were then holding for 3 hours. Carburizing process using coconut shell charcoal media previously chemically activated using H2SO4 0,5 M. Characterization of microstructure of steel specimens using an optical microscope. Test results for the raw material microstructure predominantly ferit phase and the carburizing specimen with holding time for 3 hours at a temperature of 923oC dominated by martensite phase. Keywords: Steel JIS SCM 415, carburizing, microstructure.

Pengaruh Variasi Kecepatan Aliran Gas CO2 Terhadap Kemurnian dan Ukuran Kristal Nanokalsit dari Cangkang Kerang Bulu dengan Metode Karbonasi Ika Nurjanah; Nugrahani Primary Putri; Lydia Rohmawati
Inovasi Fisika Indonesia Vol 2 No 3 (2013)
Publisher : Jurusan Fisika FMIPA Universitas Negeri Surabaya

Abstrak Penelitian ini bertujuan untuk memperoleh nanokalsit cangkang kerang dengan metode karbonasi. Kecepatan aliran gas CO2 mempengaruhi pembentukan nanokalsit cangkang kerang. Variabel ini mempengaruhi kandungan dan ukuran kristal kalsit. Cangkang kerang dikalsinasi pada suhu 900˚C selama 5 jam kemudian dilarutkan dalam HCl 10M. Setelah diperoleh larutan CaCl2, untuk memperoleh pH 10 ditambahkan NH4OH. Selanjutnya dilakukan proses karbonasi selama 10 menit dengan kecepatan aliran gas CO2 1,4 liter/menit; 2,8 liter/menit; 3,7 liter/menit; dan 4,7 liter/menit. Selanjutnya dilakukan proses pengendapan selama 36 jam. Hasil proses pengendapan disaring dan dikeringkan pada suhu 90oC selama 24 jam. Melalui pengujian XRD setelah proses karbonasi teridentifikasi sampel mempunyai kandungan kalsit dan vaterit. Kandungan kalsit paling tinggi diperoleh pada kecepatan aliran gas CO2 2,8 liter/menit sebesar 97,54%. Ukuran kristal kalsit minimum sebesar 92,96 nm diperoleh pada kecepatan aliran gas CO2 1,4 liter/menit. Kata Kunci: nanokalsit, kalsinasi, karbonasi, rietveld Abstract This study aimed to obtain nanocalcite shells with carbonation method. Flow velocity of CO2 gas affects the formation nanocalcite shells. This variable affects the content and size of the calcite crystal. Shells calcined at 900 ˚ C for 5 hours and then dissolved in 10M HCl. Having obtained the CaCl2 solution, to obtain pH 10 added NH4OH. Then carbonation for 10 min at a flow velocity of CO2 gas 1.4 liter/min; 2.8 liters/min; 3.7 liters/min, and 4.7 liters/min. Deposition process is then performed for 36 hours. Deposition process results filtered and dried at a temperature of 90oC for 24 hours. Through XRD testing after carbonation process the samples have been identified calcite and vaterite. Content of calcite optimum at flow velocity of CO2 gas 2.8 liters/min at 97.54%. Minimum size of calcite crystals of 92.96 nm at a flow velocity of CO2 gas 1.4 liter/min. Key word: nanocalcite, calcination, carbonation, rietveld

ANALYSIS OF CRYSTALLINE PHASE AND FUNCTIONAL GROUPS OF ZnO FROM PINEAPPLE PEEL EXTRACT Rosalia Santika; Lydia Rohmawati
Indonesian Physical Review Vol. 5 No. 3 (2022)
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/ipr.v5i3.160

The use of pineapple peel has not been paid attention to because of the lack of public knowledge regarding the content and benefits of pineapple skin. However, it can use pineapple skin for herbal drinks and animal feed. Pineapple peel has phytochemical compounds and bioactive compounds such as ZnO. Therefore, this study was conducted to determine ZnO's crystalline phase and the functional group from pineapple peel extract. Synthesis of ZnO from pineapple peel extract used the green synthesis method, with the following steps: pineapple peel was pounded and stirred by heating at 80°C, and then ultrasonicated. The solution was added with NaOH and centrifuged at 4000 rpm. This result is heated at a temperature of 120°C with a 6 and 12 hours holding time. After that, it cooled to room temperature. The results of XRD analysis obtained the optimal ZnO crystalline phase at a holding time of 12 hours according to the pdf cards database (96-210-7060) and nanocrystalline size of 17.55 nm. The FTIR results on the ZnO sample had an absorption peak of 4000-400cm-1 with functional groups O-H alcohol and phenol, -C=C alkene, C=O, C-O, C-N, and Zn-O. It is hoped to be applied later in the medical and industrial fields by obtaining ZnO samples from pineapple peel extract

Aplikasi Nanopartikel Zno dari Limbah Kulit Nanas (Ananas Comosus) untuk Mendukung Ketersediaan Disinfektan SARS Cov- 2 Fitria Tahta Alfina; Nur Anisa Rosyiidah; Riski Ramadani; Yeremia Ajijaya Putra Ritiau; Lydia Rohmawati
Prosiding Seminar Nasional Unimus Vol 5 (2022): Inovasi Riset dan Pengabdian Masyarakat Guna Menunjang Pencapaian Sustainable Developm
Publisher : Universitas Muhammadiyah Semarang

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

Penyebaran virus COVID-19 di Indonesia semakin luas, dimana varian virus tersebut adalah Severe Acute Respiratory Syndrome Coronavirus 2 (SARS CoV-2). Virus ini mampu menginfeksi manusia bahkan menyebabkan kematian. Model penularan dari SARS CoV-2 terdapat dua cara yaitu secarakontak langsung dan tidak langsung. Penularan menjadi berkembang seiring berjalannya waktu, maka perlunya pengendalian penularan SARS CoV-2 untuk mengurangi infeksi. Salah satu senyawa yang dapat digunakan untuk mereduksi virus ini adalah nanopartikel ZnO. Senyawa ini memiliki karakteristik antikanker, biodegradable, biokompatibilitas baik dengan sel manusia dan antibakteri sehingga dapat dimanfaatkan sebagai antiviral SARS CoV-2. Dalam memperoleh ZnO dari kulit nanas digunakan metode green synthesis. Pembuatan ekstraksi kulit nanas dengan cara maserasi menggunakan methanol dan filtrat yang diperoleh sebagai larutan bioaktif dalam sintesis nanopartikel ZnO. Kandungan senyawa ZnO diidentifikasi menggunakan metode molecular docking untuk memprediksi efektifitas disinfektan dengan daya hambat terhadap virus pada protein target SARS-CoV-2 jenis MPro 7ALH. Uji karakterisasi X-Ray Diffraction dan uji in silico dilakukan untuk mengidentifikasi fasa, struktur, serta kualitas kristal sampel serta daya hambat terhadap aktivitas protein reseptor. Hasil analisa XRD memperoleh bahwa memiliki fasa zincite dengan puncak difraksi maksimum berada di sudut 36.33°. Ukuran partikel dapat ditentukan menggunakan formula DebyeScherrer, sehingga diperoleh sebesar 13,45 nm. Pengujian in silico dilakukan agar senyawa ini dapatmenjadi disenfektan untuk SARS CoV-2 melalui interaksi antara ligan-reseptor dengan nilai binding affinity sebesar -6.31 kcal/mol dan inhibitor constant sebesar 23.60 mM.Kata Kunci : kulit nanas, nanopartikel ZnO, disinfektan

Co-Authors Fitria Tahta Alfina Ika Nurjanah Nugrahani Primary Putri Nur Anisa Rosyiidah RIA DWI IZHYANTI Riski Ramadani Rosalia Santika Sri Maulidiyah Mangkuasih Yeremia Ajijaya Putra Ritiau

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