Jurnal Fisika : Fisika Sains dan Aplikasinya最新文献

{"title":"ANALISIS SIFAT MEKANIK MODIFIKASI KEMIRINGAN MERCU SPILLWAY TIPE OGEE DENGAN STUDI KASUS BENDUNGAN RAKNAMO MENGGUNAKAN METODE ELEMEN HINGGA SOFTWARE ELMER","authors":"San Arnolus Kain, Ali Warsito, Minsyahril Bukit, A. Johannes","doi":"10.35508/fisa.v7i1.3964","DOIUrl":"https://doi.org/10.35508/fisa.v7i1.3964","url":null,"abstract":"Abstrak \u0000 Penelitian tentang analisis sifat mekanik modifikasi kemiringan mercu Spillway Tipe Ogee menggunakan metode elemen hingga software ELMER telah dilakukan. Tujuan penelitian ini adalah menganalisis besar tegangan, regangan dan deformasi pada mercu spillway bendungan tipe ogee dengan metode elemen hingga. Struktur bendungan dimodelkan dengan bantuan software FreeCAD, kemudian perhitungan metode elemen hingga dengan software Elmer dan dilanjutkan analisis dengan software ParaView. Berdasarkan hasil analisis mercu Spillway tipe Ogee dengan modifikasi kemiringan 41.18o, 45o dan 48.36o menunjukkan tegangan maksimum pada kemiringan 41.18o terjadi pada bagian dinding mercu spillway pada arah sumbu z dengan nilai 2.2 x 105 N/m2, sedangkan tegangan maksimum pada kemiringan 45o  dan 48.36o terjadi pada bagian segmen dasar mercu spillway pada arah sumbu xy dengan nilai secara berurutan  2.5 x 105 N/m2 dan 3.0  x 105 N/m2. Regangan yang terjadi pada ketiga modifikasi kemiringan berurutan sebesar 35 x 10-8 , 47.5 x 10-8, dan 65 x 10-8. Deformasi yang terjadi pada ketiga modifikasi berurutan sebesar 1.4 x 10-5 m, 1.9 x 10-5 m dan 2.6x10-5 m. Dari analisis sifat mekanik modifikasi kemiringan mercu Spillway Tipe Ogee dapat disimpulkan bahwa perubahan nilai regangan dan deformasi semakin besar jika kemiringan mercu Spillway bertambah. Sedangkan nilai tegangan maksimum terjadi pada bagian dinding dan bagian segmen dasar mercu  spillway. \u0000 Kata Kunci : Metode Elemen Hingga, Spillway ogee, tegangan, regangan, deformasi. \u0000  \u0000Abstract \u0000 Research on the mechanical properties of the modification of the ogee spillway dam with slope variations has been caried out using the finite element method ELMER software. The purposes of this study were to analyze the magnitude of stress, strain and deformation on the ogee spillway. The structure of the dam was modeled with a FreeCAD software, then the calculation of the finite element method with an Elmer software and the analysis used ParaView software. Based on the analysis of the ogee spillway type with slopes of 41.18o, 45o and 48.36o, the maximum stress at the slope of 41.18o occurs in the wall section of the crest spillway in the z axis direction with a value of 2.2 x 105 N/m2, while the maximum stress at the slope of 45o and 48.36o occurs in the base segment of the crest spillway in the xy axis direction with values of 2.5 x 105 N/m2 and 3.0 x 105 N/m2 respectively. The strains that occurs in the three sequential tilt modifications were 35 x 10-8, 47.5 x 10-8, and 65 x 10-8. The deformation occurs in the three sequential modifications of 1.4 x 10-5 m, 1.9 x 10-5 m and 2.6 x 10-5 m. From the analysis of the mechanical properties of the modification of the crest spillway ogee Type it can be concluded that the change in strain and deformation values is greater if the slopes of the crest spillway increases. While, the maximum stress value occurs in the wall and the base segment of the mercu spillway. \u0000 Keywords : Finite e","PeriodicalId":367071,"journal":{"name":"Jurnal Fisika : Fisika Sains dan Aplikasinya","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130035574","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}

{"title":"ANALISIS KEKUATAN IMPAK KOMPOSIT HYBRID SERAT LONTAR DAN SERAT GELAS UNTUK APLIKASI HELM KENDARAAN BERMOTOR","authors":"Andre Juanda Baru, J. S. Bale, Yeremias M. Pell","doi":"10.35508/fisa.v7i1.5894","DOIUrl":"https://doi.org/10.35508/fisa.v7i1.5894","url":null,"abstract":"The fiber content of lontar fruit can be utilized in a non-metal composite substitute for a more expensive metal composite. Currently, non-metallic materials are widely used as substitutes for metal materials because they have various advantages, namely being lighter in weight, easier to shape, and cheaper. One of these non-metallic materials is fiberglass. The purpose of this study was to determine the effect of alkali treatment on the impact properties of polyester fiber reinforced palm fiber and glass fiber composites, the effect of concentrations of 5%, 10%, and 15% Alkali (NaOH) on the impact properties, and treatment time 0, 2, 4, and 6 hours on Impact properties of polyester composites reinforced with palm fiber and glass fibers. 20% of the test specimens were made according to the ASTMD256-04 standard and tested with an impact tester. The results of the impact test showed that composites with hybrid fibers (palm fiber and glass fiber) as well as composites with palm fiber which were treated with alkali tended to have greater impact properties than those not treated with alkali. Fiber-reinforced composites treated with 15% alkali had the highest average toughness, while the lowest impact toughness was composites with fiber reinforcement treated with 5% alkali. The length of time of treatment had an effect on the impact toughness of the composites.","PeriodicalId":367071,"journal":{"name":"Jurnal Fisika : Fisika Sains dan Aplikasinya","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115295498","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}

{"title":"PEMETAAN DAERAH RAWAN EROSI DENGAN MENNGUNAKAN METODE UNIVERSAL SOIL LOSS EQUATION (USLE) DI KOTA KUPANG","authors":"Elsa Yovanka Neolaka, Jehunias Leonidas Tanesib, Bernandus Bernandus","doi":"10.35508/fisa.v7i1.6081","DOIUrl":"https://doi.org/10.35508/fisa.v7i1.6081","url":null,"abstract":"The research has done about mapping of erosion-prone areas using the USLE method in Kupang city. The purpose of this research is to map erosion-prone areas and determine the potential level of erosion hazard in Kupang city. The parameters used are rain erosivity (R), soil erodibility (K), slope (LS), and land cover (CP). The process of overlaying erosion parameters and calculating the rate of erosion produces erosion hazard map which are categorized into five class, namely very light, light, medium, heavy and very heavy. Very light erosion (<15 tons/ha/year) has the largest area of 104.92 km², light erosion class (15-60 tons/ha/year) with an area of 28.32 km², medium erosion class (60-180 tons/ha/year) with an area of 13.37 km², heavy erosion class (180-480 tons/ha/year) with an area of 2.37 km², and very heavy erosion class (>480 tons/ha/year) has the smallest area of 0.526 km². The level of erosion hazard is very light and light spread throughout the city of Kupang. While the level of medium to very heavy erosion hazard is widely spread in Alak sub-district, especially the villages of Alak, Manutapen, Nunbaun Sabu, Batuplat, Manulai II. In the Maulafa sub-district spread in the villages of Sikumana and Belo. And several points in the villages of Tuak Daun Merah and Liliba, especially in the river area. \u0000 ","PeriodicalId":367071,"journal":{"name":"Jurnal Fisika : Fisika Sains dan Aplikasinya","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121411407","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}

{"title":"UJI COBA METODE PENCITRAAN MULTIMODALITAS ULTRASONOGRAFI DAN FOTOAKUSTIK","authors":"Edo Robby Sanjaya, Jodelin Muninggar, Andreas Setiawan","doi":"10.35508/fisa.v7i1.6680","DOIUrl":"https://doi.org/10.35508/fisa.v7i1.6680","url":null,"abstract":"Ultrasonografi (USG) adalah pembentukan citra suatu objek menggunakan gelombang akustik frekuensi tinggi. Dengan penggunaan akustik ini maka USG tidak dapat digunakan untuk memantau suatu warna organ atau jaringan yang memiliki bentuk dan ukuran yang sama, namun memiliki warna berbeda. Dalam penelitian ini diusulkan pengamatan USG multimode yaitu penggabungan antara USG dan fotoakustik. Proses ini diharapkan dapat meningkatkan fungsi citra USG yang dapat sekaligus membedakan warna obyek. Efek fotoakustik adalah pembentukan gelombang suara akibat penyerapan cahaya termodulasi pada obyek. Percobaan dilakukan dengan mengarahkan sinar laser termodulasi pada suatu titik wadah yang berisikan air. Dalam langkah ini diharapkan interaksi fotoakustik akan menghasilkan gelombang akustik yang dapat dideteksi oleh sensor USG. Hasil percobaan menunjukkan meskipun efek fotoakustik terjadi namun sinyal terlalu lemah untuk dideteksi USG. Oleh sebab itu pada percobaan ini dilakukan juga pengujian dengan sumber akustik eksternal. Dapat diperlihatkan meskipun perubahan cukup kecil gelombang akustik mampu menggangu obyek yang diukur sehingga menghasilkan citra USG yang berbeda. Hasil ini menunjukan potensi pengembangan lebih lanjut metode USG multimode dengan fotoakustik.","PeriodicalId":367071,"journal":{"name":"Jurnal Fisika : Fisika Sains dan Aplikasinya","volume":"149 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133998200","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}

{"title":"KAJIAN PUSTAKA KOMPOSIT LIMBAH PLASTIK SEBAGAI PAVING BLOK PENGHASIL ENERGI BERKELANJUTAN TERINTEGRASI PIEZOELEKTRIK DAN PHOTOVOLTAIC (VIZO)","authors":"Farah Yuki Prasetyawati, M. Yusuf, Alvin Ichwannur Ridho, Afifah Harwanti, Yulianto Agung Rezeki, S. Sarwanto, D. Harjunowibowo, Sri Budiawanti, Suharno Suharno, Yesiana Arimurti, D. Rahardjo","doi":"10.35508/fisa.v7i1.5478","DOIUrl":"https://doi.org/10.35508/fisa.v7i1.5478","url":null,"abstract":"This work aims to improve pedestrian functions, improve the welfare of waste banks and scavengers, and fulfil electricity needs for the surrounding community towards Society 5.0. The method of writing is done with secondary data through the latest literature study. The literature study focused on the development of technology for processing plastic waste, photovoltaic (PV), and piezoelectric (PZT) and their use in road construction. The results of the discussion show the potential of plastic waste as a composite material for paving. Similarly, PV and PZT can be integrated together as a producer of renewable electrical energy. With this innovation, VIZO is expected to be able to reduce plastic waste and provide welfare for the community, scavengers, waste banks, and help local government energy-saving programs.","PeriodicalId":367071,"journal":{"name":"Jurnal Fisika : Fisika Sains dan Aplikasinya","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124551297","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}

{"title":"ANALISIS KINERJA TURBIN SAVONIUS SEBAGAI SUMBER ENERGI ALTERNATIF","authors":"Imanuel Oktovianus Silla, Arifin Sanusi, Yeremias M. Pell","doi":"10.35508/fisa.v7i1.3811","DOIUrl":"https://doi.org/10.35508/fisa.v7i1.3811","url":null,"abstract":"Salah satu energi yang tidak dapat lepas dari kehidupan kita yakni, energi listrik. Sumber energi listrik dapat dikelompokkan menjadi dua yaitu energi yang dapat diperbaharui dan yang tidak dapat diperbaharui. Penggunaan energi alternatif berupa energi yang dapat diperbaharui (terbarukan) perlu dilakukan penelitian untuk pemanfaatan yang lebih luas. Salah satu energi alternatif yang perlu mendapat perhatian yakni energi angin dimana pemanfaatannya memerlukan turbin angin. Turbin angin tipe Savonius merupakan salah satu turbin angin poros vertikal (VAWT) dengan kontruksi sederhana dimana memiliki rotor utama yang berputar secara vertikal dan memiliki kelebihan yang dapat memanfaatkan angin dari semua arah, mampu bekerja pada kecepatan yang rendah, serta tidak memerlukan menara yang terlalu tinggi. Berdasarkan hal tersebut diatas maka dalam penelitian ini dipilih menggunakan turbin angin Savonius dua blade karena membutuhkan putaran yang relatif rendah. Adapun metode yang digunakan dalam penelitian ini adalah melakukan pengukuran langsung terhadap putaran turbin. Tahapan yang dilakukan yaitu mengukur kecepatan angin, torsi turbin, dan tip speed ratio dimana dalam perhitungan dan analisa menggunakan rumus-rumus yang berhubungan dengan Torsi, Koefisien Daya, Koefisien Torsi dan Tip Speed Ratio.Hasil perhitungan dan analisa diperoleh (1) Kecepatan rata-rata angin yang terukur di desa Oenali adalah 8.26 m/s mampu memutar turbin Savonius dengan putaran rata-rata sebesar 654 rpm sehingga menghasilkan Torsi Turbin (Tt) sebesar 0.33 N.m. (2) Koefisien Daya (CP) sebesar 2.8 (%) dengan tip speed ratio sebesar 0.6 (λ). (3) Koefisien Torsi (CT) diperoleh sebesar 8.7 (%), dan Tip Speed Ratio yang diperole sebesar 0.1 (λ).","PeriodicalId":367071,"journal":{"name":"Jurnal Fisika : Fisika Sains dan Aplikasinya","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131166744","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}

{"title":"PEMBUATAN BIOPLASTIK BERBAHAN DASAR PATI JAGUNG DENGAN PENAMBAHAN SERAT SELULOSA DARI LIMBAH KERTAS","authors":"Intan Permata Dewi, A. Johannes, R. K. Pingak, Minsyahril Bukit, H. I. Sutaji","doi":"10.35508/fisa.v6i2.6838","DOIUrl":"https://doi.org/10.35508/fisa.v6i2.6838","url":null,"abstract":" Abstrak \u0000Plastik konvensional yang sering digunakan dalam kehidupan sehari-hari menyebabkan terjadinya penumpukan limbah plastik dan menyebabkan masalah pencemaran lingkungan karena plastik sulit terurai oleh mikroorganisme. Bioplastik merupakan salah satu solusi yang digunakan dalam mengurangi pencemaran lingkungan, sifatnya yang mudah terdegradasi dan terurai oleh mikroorganisme dalam waktu yang cukup singkat membuat plastik tersebut ramah lingkungan. Bahan yang digunakan dalam pembuatan bioplastik pada penelitian ini adalah pati jagung dan serat selulosa yang diekstrak dari kertas bekas menggunakan metode Asetilasi. Tujuan umum dari penelitian ini, adalah untuk mengetahui pengaruh penambahan serat selulosa pada sampel bioplastik dengan gliserol berperan sebagai pemlastis. Analisis bioplastik dilakukan dengan melakukan pengukuran uji kekuatan tarik, uji daya serap air, uji biodegradasi, dan pengamatan struktur menggunakan mikroskop optik. Hasil uji kuat tarik terbaik didapat pada penambahan 2 gram pulp selulosa, dengan nilai kuat tarik sebesar 1,65 MPa dan persentase nilai elongasi sampel 25%. Untuk uji daya serap air dengan persentase terkecil didapat pada penambahan 1 gram pulp dengan nilai 35,48%. Hasil uji biodegradasi terbaik adalah pada penambahan 1 gram dan 2 gram, dengan lama waktu degradasi 13 hari. \u0000  \u0000Abstract \u0000 Conventional plastics which are often used in everyday life cause the accumulation of plastic waste and cause environmental pollution problems because plastics are difficult to decompose by microorganisms. Bioplastic is one of the solutions used in reducing environmental pollution, its nature is easily degraded and decomposed by microorganisms in a fairly short time making the plastic environmentally friendly. The materials used in the manufacture of bioplastics in this study are corn starch and cellulose fibers which are extracted from wasted paper using the acetylation method. The general objective of this study was to determine the effect of adding cellulose fibers to bioplastic samples with glycerol acting as plasticizers. Bioplastic analysis is carried out by measuring the tensile strength test, water absorption test, biodegradation test, and observing the structure using an optical microscope. The best tensile strength test results were obtained in the addition of 2 grams of cellulose pulp, with a tensile strength value of 1.65 MPa and a percentage of the sample's elongation value of 25%. For the water absorption test with the smallest percentage was obtained the addition of 1 gram of pulp with a value of 35.48%. The best biodegradation test results were in the addition of 1 gram and 2 grams, with a degradation time of 13 days. \u0000 ","PeriodicalId":367071,"journal":{"name":"Jurnal Fisika : Fisika Sains dan Aplikasinya","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121075192","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}

{"title":"EFEK SINTESIS SILANE COUPLING AGENT PADA SIFAT FISIS DAN MEKANIS KOMPOSIT SERBUK KENAF","authors":"Delovita Ginting, Reka Nuansa Fitri","doi":"10.35508/fisa.v6i2.6841","DOIUrl":"https://doi.org/10.35508/fisa.v6i2.6841","url":null,"abstract":"Abstrak \u0000 Penelitian ini bertujuan untuk melihat efektivitas perlakuan kimia larutan silane coupling agent terhadap sifat fisis (densitas dan daya serap air) dan sifat mekanis (kuat tarik dan kuat pukul takik) dari komposit serbuk kenaf. Serbuk kenaf dialkalisasi dengam menggunakan NaOH selama 4 jam, kemudian dihaluskan mengunakan greending machine hingga lolos ayakan 50 mesh. Serbuk kenaf yang telah lolos ayakan kemudian diolah secara kimia dengan larutan silane coupling agent.  Variasi konsentrasi larutan silane coupling agent yang digunakan adalah dengan konsentrasi 0%, 10%, 20% dan 30% terhadap massa serbuk kenaf. Serbuk kenaf yang telah disintesis dengan silane coupling agent kemudian dicampur dengan perekat resin epoksi dengan perandingan 30/70 dalam persen berat. Proses kompaksi komposit menggunakan mesin kompaksi Hydrolic Hot Press dengan tekanan 20 Bar pada suhu 125 oC dan waktu penahanan 15 menit. Hasil dari penelitian ini bahwa dengan perlakuan 20% silane coupling agent pada serbuk kenaf efektif meningkatkan sifat fisis dan mekanis komposit. \u0000 Abstract \u0000 This study aims to see the effectiveness of the chemical treatment of silane coupling agent on the physical properties (density and water absorption) and mechanical properties (tensile strength and impact strength) of the kenaf powder composite. Kenaf powder was alkalized using NaOH for 4 hours, then mashed using a grinding machine until it passed a 50 mesh sieve. The kenaf powder that has passed the sieve is then chemically treated with a silane coupling agent solution. Variations in the concentration of the silane coupling agent solution used were 0%, 10%, 20% and 30% of the mass of kenaf powder. Kenaf powder which has been synthesized with a silane coupling agent is then mixed with epoxy resin adhesive with a ratio of 30/70 in weight percent. The composite compaction process uses a Hydrolic Hot Press compacting machine with a pressure of 20 Bar at a temperature of 125 oC and a holding time of 15 minutes. The result of this research is that the treatment with 20% silane coupling agent on kenaf powder is effective in improving the physical and mechanical properties of the composite.","PeriodicalId":367071,"journal":{"name":"Jurnal Fisika : Fisika Sains dan Aplikasinya","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131305727","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}

{"title":"KARAKTERISTIK PERISTIWA PETIR TERKAIT CURAH HUJAN DI WILAYAH MAUMERE NUSA TENGGARA TIMUR","authors":"Riski Basrin, H. I. Sutaji, Apolinaris S. Geru, Jehunias Leonidas Tanesib","doi":"10.35508/fisa.v6i2.6836","DOIUrl":"https://doi.org/10.35508/fisa.v6i2.6836","url":null,"abstract":"Abstrak \u0000 Telah dilakukan penelitian tentang karakteristik peristiwa petir, khususnya jenis Cloud to Gground (CG) terkait curah hujan (CH) di wilayah Nusa Tenggara Timur (NTT). Hasil penelitian menunjukkan bahwa total sambaran petir CG yang terjadi di wilayah Maumere pada periode bulan Desember 2014 sampai November 2019 sebesar 18.194 sambaran dengan sambaran maksimum terjadi pada bulan Nopember sampai April dan sambaran minimum terjadi di bulan Juli sampai Oktober. Untuk curah hujan yang terjadi pada daerah Maumere dan periode tersebut sebesar 4.201 mm dengan pola hujan bertipe monsunal, dimana curah hujan maksimum terjadi di bulan Desember sampai Februari, sedangkan curah hujan minimum terjadi pada bulan Juli sampai Oktober. Peristiwa sambaran petir CG dan curah hujan di wilayah tersebut, umumnya memiliki hubungan yang tidak searah atau tidak kuat namun tergolong pada korelasi sedang. Selain itu, jumlah peristiwa sambaran petir untuk jumlah curah hujan pada setiap tahunnya berbeda yang ditunjukkan dengan nilai perhitungan Rain-Yield per Flash (RPF). Hal ini diduga karena adanya beberapa faktor, seperti perubahan cuaca yang begitu cepat, pergerakan angin yang kencang serta adanya faktor lama penyinaran matahari yang terjadi di wilayah tersebut. \u0000  \u0000Abstract \u0000 Research on the characteristics of lightning events has been carried out, especially the type of cloud to ground (CG) related to rainfall (CH) in the East Nusa Tenggara (NTT) region. The result showed that the total CG lightning strikes that occurred in the Maumere area in the period December 2014 to November 2019 were 18.194 strikes with the maximum strikes occurring from November to April and the minimum incidents occurring from July to October. The rainfall that occurs in these Maumere regions and periods is 4.201 mm with a monsoon-type rain pattern, where the maximum rainfall occurs in December to February, while the minimum rainfall occurs from July to October. The CG lightning strikes events and rainfall in the area, generally have a unidirectional or not strong relationship but are classified as moderate correlation. Also In addition, the number of lightning strikes events for the amount of rainfall in each year is different as indicated by the Rain-Yield per Flash (RPF) calculation value. This is presumably due to several factors, such as rapid weather changes, strong wind movements, and the long time factor of sun exposure in the area.    \u0000 ","PeriodicalId":367071,"journal":{"name":"Jurnal Fisika : Fisika Sains dan Aplikasinya","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125531300","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}

{"title":"KARAKTERISASI CARBON NANODOTS BERBAHAN DASAR LIMBAH IKAN TONGKOL","authors":"Elisabeth Pratidhina, Michael Jurdan, Pearl Abigail Ermanto, J. Prabowo, Johannes Benedictus Vidi Atmanjaya, Maria Margareta Meylinda Bhoki","doi":"10.35508/fisa.v6i2.6842","DOIUrl":"https://doi.org/10.35508/fisa.v6i2.6842","url":null,"abstract":"Abstrak \u0000 Carbon nanodots (CDs) adalah nanomaterial yang memiliki karakteristik dapat memancarkan cahaya setelah menyerap cahaya dengan panjang gelombang yang berbeda. Carbon nanodots (CDs)juga dikenal memiliki sifat optik yang baik, mudah larut dalam air, stabil, memiliki toksisitas rendah, dan dapat disintesis dengan metode sederhana. Carbon nanodots (CDs)dapat dibuat dari limbah biomassa seperti limbah ikan tongkol. Penelitian ini dilakukan untuk melakukan karakterisasicarbonnanodots dari limbah ikan tongkol. Karakterisasicarbon nanodots (CDs)secara berturut-turut dilakukan dengan penjemuran tulang ikan selama 8 hari, pengovenan pada suhu 2000C selama 1 jam, penghancuran dengan grinder, dan pengovenan kembali pada suhu 2500C dengan lama waktu pengovenan 2 jam, 3 jam, dan 4 jam. Penyiapan sampel dilakukan dengan mencampurkan masing-masing 1 gram bubuk hasil pengovenan dengan akuades 50 mL. Campuran kemudian secara berturut-turut diaduk selama 30 menit, didiamkan selama 30 menit, di centrifuge, dan disaring. Sampel kemudian dikarakteristik dengan analisis UV-Vis dan PL untuk menganalisis sifat-sifat optis. Analisis FTIR juga dilakukan untuk mengidentifikasi gugus fungsi. Berdasarkan analisis UV-Vis, semua variasi sampel menunjukkan panjang gelombang puncak absorbsi sekitar 265 nm. Berdasaran analisis PL, sampel menunjukkan intensitas maksimum pada panjang gelombang antara 470-500 nm, sehingga carbon nanodots mengemisikan cahaya berwarna biru ketika disinari dengan senter UV. Gugus fungsi yang tampak dari analisis FTIR adalah C=C, CºC, O-H, dan C=O=C. \u0000  Abstract \u0000Carbon nanodots (CDs) are nanomaterials that have the characteristics of being able to emit light after absorbing light with different wavelengths. Carbon nanodots (CDs) are also known to have good optical properties, are easily soluble in water, are stable, have low toxicity, and can be synthesized by simple methods. Carbon nanodots (CDs) can be made from biomass waste such as tongkol (Euthynnus affinis) waste. This research was conducted to characterize carbon nanodots from tongkol (Euthynnus affinis) waste. The characterization process are drying the fish bones for 8 days, placing in the oven at 2000C for 1 hour, crushing with a grinder, and placing again in the oven at 2500C for 2 hours, 3 hours, and 4 hours. The sample preparation are mixing 1 gram of each powder with 50 mL aqudes, stirring up the mixture for 30 minutes, standing it for 30 minutes, centrifuging, and filtering. The samples were characterized by UV-Vis and PL analysis to analyze their optical characteristics. FTIR analysis also carried out to identify the functional groups. Based on the UV-Vis analyzes, all the different samples showed the peak absorption wavelength around 265 nm. Based on the PL analyzes, the wavelength maximum intensity is between 470 and 500 nm and emitted blue light when irradiated with a UV flashlight. The functional groups shown from FTIR are C=C, CºC, O-H, andC=O=C.","PeriodicalId":367071,"journal":{"name":"Jurnal Fisika : Fisika Sains dan Aplikasinya","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126988353","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}