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BACK MATTER SPEKTRA VOLUME 3 ISSUE 2 AUGUST 2018 Back matter spectra第三卷2018年8月2日

Spektra: Jurnal Fisika dan Aplikasinya Pub Date : 2018-08-30 DOI: 10.21009/spektra.032111

Editor Spektra

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FRONT MATTER SPEKTRA VOLUME 3 ISSUE 2 AUGUST 2018 2018年8月2日

Spektra: Jurnal Fisika dan Aplikasinya Pub Date : 2018-08-30 DOI: 10.21009/spektra.03200

Editor Spektra

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UV-VISIBLE OPTICAL ABSORBANCE OF GRAPHENE OXIDE IN COPPER IONIC LIQUID SYNTHESIZED VIA ELECTROCHEMICAL METHOD ASSISTED BY A COPPER COIL 铜线圈辅助下电化学合成的铜离子液体中氧化石墨烯的紫外-可见光吸光度

Spektra: Jurnal Fisika dan Aplikasinya Pub Date : 2018-08-30 DOI: 10.21009/spektra.032.02

W. Dwandaru, Oktiana Lusi Priyani, B. Prakoso, R. I. Wisnuwijaya, I. Santoso

{"title":"UV-VISIBLE OPTICAL ABSORBANCE OF GRAPHENE OXIDE IN COPPER IONIC LIQUID SYNTHESIZED VIA ELECTROCHEMICAL METHOD ASSISTED BY A COPPER COIL","authors":"W. Dwandaru, Oktiana Lusi Priyani, B. Prakoso, R. I. Wisnuwijaya, I. Santoso","doi":"10.21009/spektra.032.02","DOIUrl":"https://doi.org/10.21009/spektra.032.02","url":null,"abstract":"An optical absorbance study using Ultraviolet-Visible (UV-Vis) spectrophotometer device has been conducted on graphene oxide (GO) in copper (Cu) ionic liquid using electrochemical exfoliation combined with a direct current (DC) electrical circuit of copper coil given inside the electrolyte solution. The electrolyte solutions used are sulfuric acid (H2SO4) and chloride acid (HCl). The UV-Vis spectrum of the samples shows absorbance peaks at around 214 nm to 218 nm and shouldering peaks around 245 nm to 249 nm. The first peak corresponds to the existence of copper (Cu) ionic liquid in the solution, whereas the shouldering peak is related to the occurrence of GO material. A comparison between UV-Vis spectral of graphite in dimethylformamide (DMF) and GO in Cu ionic liquid in DMF resulted in the existence of a blue shift which signifies the production of Cu ionic liquid from the Cu coils inside the electrolyte solution. Increasing the concentration of the solution increases the absorbance peaks. Furthermore, raising the number of loops yields in the increase of the absorbance value at the first peaks that show Cu ionic liquid, but tends to decrease the absorbance value of the shouldering peaks of the GO material.","PeriodicalId":117601,"journal":{"name":"Spektra: Jurnal Fisika dan Aplikasinya","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134153521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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MODEL MATERI GELAP DUA FLUIDA STATIS DENGAN TAMBAHAN KONSTANTA KOSMOLOGI 将两种流体静态暗物质与宇宙学额外常数模型

Spektra: Jurnal Fisika dan Aplikasinya Pub Date : 2018-08-21 DOI: 10.21009/SPEKTRA.032.07

Izrul Supriyadi, W. Sawitar, Esmar Budi, Riser Fahdiran

{"title":"MODEL MATERI GELAP DUA FLUIDA STATIS DENGAN TAMBAHAN KONSTANTA KOSMOLOGI","authors":"Izrul Supriyadi, W. Sawitar, Esmar Budi, Riser Fahdiran","doi":"10.21009/SPEKTRA.032.07","DOIUrl":"https://doi.org/10.21009/SPEKTRA.032.07","url":null,"abstract":"Abstrak \u0000Pada persamaan medan gravitasi Einstein terdapat konstanta kosmologi sebagai konstanta alam yang menjelaskan model mengembangnya alam semesta dan yang paling dominan terdapat di jagad raya ini adalah dalam bentuk energi gelap (dark energy). Kami meninjau model objek dua fluida tidak terkopel, seperti layaknya materi gelap (dark matter) atau bintang yang memiliki karakteristik tensor energi-momentum dan kecepatan-4 nya yang berbeda serta bersifat anisotropik, kemudian disatukan sebagai model dua fluida untuk ditinjau persamaan TOV (Tolman-Oppenheimer-Volkoff) dan persamaan geodesiknya dalam menunjukkan sifat gerak dan model dua fluida tersebut. Hasil perhitungan menunjukkan bahwa model ini dapat menjelaskan persamaan potensial efektif dengan tambahan konstanta kosmologi sebagai karakteristik gerak dan kecepatan tangensial partikel uji dalam orbit lingkaran stabil. \u0000Kata-kata kunci: konstanta kosmologi, anisotropik, potensial efektif, kecepatan tangensial. \u0000Abstract \u0000In Einstein's gravitational field equation has been found the cosmological constant as the natural constant that describes the universe's expansion model and the most dominant in the universe is the dark energy form. We review the two objects of fluid models are not coupled, like dark matter or stars which has the different characteristic energy-momentum tensor and four velocities and anisotropic tend, then combined as two-fluid models for TOV (Tolman-Oppenheimer-Volkoff) equation and the geodesic equation to characterize the movement and the two fluid models. The calculation result shows that this model can explain the potential equation with an addition of an effective cosmological constant as the movement characteristic and tangential velocity of a tested particle in a stable circular orbit. \u0000Keywords: cosmological constant, anisotropic, effective potential, tangential velocity.","PeriodicalId":117601,"journal":{"name":"Spektra: Jurnal Fisika dan Aplikasinya","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126065471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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ANALOG COMPUTER FOR STUDYING DIATOMIC MOLECULAR SPECTRA IN TERAHERTZ FREQUENCY 研究太赫兹双原子分子光谱的模拟计算机

Spektra: Jurnal Fisika dan Aplikasinya Pub Date : 2018-08-21 DOI: 10.21009/spektra.032.06

Usman Malik, Muhamad Hamdi, S. Salomo

{"title":"ANALOG COMPUTER FOR STUDYING DIATOMIC MOLECULAR SPECTRA IN TERAHERTZ FREQUENCY","authors":"Usman Malik, Muhamad Hamdi, S. Salomo","doi":"10.21009/spektra.032.06","DOIUrl":"https://doi.org/10.21009/spektra.032.06","url":null,"abstract":"This paper introduces a harmonic oscillator model for rovibronic terahertz spectrum of a model of a rigid diatomic rotor with some control parameters. The model shows a study of rotationally-resolved terahertz band spectra of the vibrational transition in diatomic molecules. THz radiation absorption is used as a closed-form system known as the analog computer dynamics mode. The optical terahertz region spectrum of the diatomic molecule consists of a series of lines. Their separations are not exactly constant. A diatomic molecule is not truly a rigid rotator, because it simultaneously vibrates with a small amplitude. Due to quantized vibrational and rotational energy levels and the selection rules, allowed transitions result in a highly ordered spectrum consisting of a P branch separated by a central gap. Adjacent spectral lines are separated by a spacing of 2B, and since line intensities depend on Boltzmann factor for thermal population and quantum number J, each branch monotonically increases and decreases. As temperature increases, more lines are observed, and line intensities decrease due to the population being spread over more rotational levels. Interactivity research also involves on effects of the fundamental vibrational frequency, rotational constant B and temperature included line width on the observed spectrum.","PeriodicalId":117601,"journal":{"name":"Spektra: Jurnal Fisika dan Aplikasinya","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127900156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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ANALISIS SIFAT OPTIK KLOROFIL PADA EKSTRAK DAUN MENGGUNAKAN UV-VIS SPEKTROMETER SEBAGAI STUDI AWAL APLIKASI DYE SENSITIZER

Spektra: Jurnal Fisika dan Aplikasinya Pub Date : 2018-08-15 DOI: 10.21009/spektra.032.04

Dona Dianisya, Amalia Dini Silmina, N. Purwanto, Isnaeni Isnaeni, I. Sugihartono

{"title":"ANALISIS SIFAT OPTIK KLOROFIL PADA EKSTRAK DAUN MENGGUNAKAN UV-VIS SPEKTROMETER SEBAGAI STUDI AWAL APLIKASI DYE SENSITIZER","authors":"Dona Dianisya, Amalia Dini Silmina, N. Purwanto, Isnaeni Isnaeni, I. Sugihartono","doi":"10.21009/spektra.032.04","DOIUrl":"https://doi.org/10.21009/spektra.032.04","url":null,"abstract":"ABSTRAK \u0000Telah dilakukan studi ekstraksi awal klorofil dari 3 jenis daun yaitu daun bayam (Amarantus), daun pepaya (Carica papaya), dan daun jarak (Ricinus communis). Ekstraksi dilakukan dengan teknik penghancuran menggunakan blender. Pelarut yang digunakan adalah isopropanol, asam asetat, dan DI water. Hasil penyaringan ekstrak daun diperoleh larutan sebayak 75 ml untuk setiap larutan ekstrak klorofil. Uji Ultrasonic Visible memberikan konfirmasi adanya penyerapan di rentang cahaya ultraviolet dan cahaya tampak. Sementara itu, serapan klorofil teramati di rentang cahaya tampak. Apabila dibandingkan serapan UV dan cahaya tampak, pada larutan ekstrak masih mengandung banyak gugus asam dibandingkan klorofil yang di ekstrak. \u0000Kata-kata kunci: daun bayam, daun pepaya, daun jarak, absorbansi, klorofil \u0000ABSTRACT \u0000We studied for chlorophyll extract from 3 leaf types that are spinach leaf (Amarantus), papaya leaf (Carica papaya), and castor leaf (Ricinus communis). The extraction is done by using a blender. The solvents used are isopropanol, acetic acid, and DI water. The result of leaf extract was obtained 75 ml solution for each solution of chlorophyll extract. The Visible Ultrasonic Test confirms absorption in the range of ultraviolet light and visible light. Meanwhile, chlorophyll uptake is observed in the visible light spectrum. When compared to UV absorption and visible light, in the extract solution still contains a lot of acid groups than the chlorophyll extracted. \u0000Keywords: spinach leaf, papaya leaf, Castor leaf, absorbance, chlorophyll.","PeriodicalId":117601,"journal":{"name":"Spektra: Jurnal Fisika dan Aplikasinya","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114448952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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