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Sintesis, Karakterisasi Struktur dan Sifat Optik Nanopartikel Hidroksiapatit/Magnetit

JPSE (Journal of Physical Science and Engineering) Vol 3, No 1 (2018): JPSE (Journal of Physical Science and Engineering)
Publisher : Universitas Negeri Malang

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Abstract

Hydroxyapatite becomes one of the promising biomaterials to be applied in medical fields due to its special performances such as biocompatible and non-toxic. So that it to improve performance of hydroxyapatite, it is necessary to develop the hydroxyapatite by compositing with magnetite. In this work, the hydroxyapatite/magnetite was synthesized using precipitated method and characterized using XRD, FTIR, SEM-EDAX, and UV-Vis spectrometer for investigating the detailed structure, functional group, morphology, and band gap energy of the prepared sample. The results show that the sample has two phases with high purity i.e. hydroxyapatite and magnetite without any impurities. The data analysis using the Scherrer’s equation shows that the hydroxyapatite/magnetite has particle size about 10 nm. Meanwhile, the data analysis using FTIR indicates the presence of atomic bond from both of hydroxyapatite and magnetite. Morphologically, it is seen that the sample has an agglomeration in the nanometric size. Interestingly, the hydroxyapatite/magnetite has a band gap energy of about 3.8 eV which is in the range of the band gap energy of hydroxyapatite and magnetite.

Kontribusi Filler Magnetik Fe3O4 pada Efek Histerisis Magneto-Elastisitas Komposit Ferogel

Jurnal Fisika dan Aplikasinya Vol 9, No 1 (2013)
Publisher : Jurnal Fisika dan Aplikasinya

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Abstract

Ferogel berbasis partikel Fe3O4 yang diperoleh dari bahan dasar pasir besi Tulungagung telah berhasil difabrikasi. Ferogel merupakan komposit hidrogel (campuran polivinil alkohol dan air) dengan filler partikel magnetit Fe3O4 dalam ukuran mikron dan nano. Hasil analisis difraksi sinar-X menunjukkan bahwa partikel magnetik Fe3O4 ukuran mikron dan nano berturut-turut sesuai dengan pola difraksi Fe3O4 yang memiliki no PDF 11-0626 dan no PDF 03-0863. Sedangkan dari hasil karakterisasi SEM dan TEM ukuran mikron partikel Fe3O4 sekitar 1-10 μm dan ukuran nano partikel Fe3O4 sekitar 11-15 nm. Kontribusi filler magnetik Fe3O4 pada komposit ferogel dapat terlihat pada karakterisasi magneto-elastisitasnya. Ketika ferogel dipengaruhi oleh medan magnetik luar yang berubah terhadap fungsi arus listrik, respon gerak ferogel cenderung membentuk pola histerisis dan menyempit seiring berkurangnya konsentrasi. Ferogel dengan filler partikel mikron Fe3O4 lebih sensitif terhadap pengaruh perubahan medan magnet dibandingkan filler partikel nano Fe3O4. Hal ini disebabkan karena magnet remanen partikel mikron Fe3O4 (8,233 emu/gr) lebih besar dibandingkan partikel nano Fe3O4 (7,995 emu/gr). Respon ferogel dalam kajian penelitian ini dapat dikembangkan untuk mensintesa otot buatan dengan pendekatan eksperimen mulai dari yang mirip penggerak pada robot sampai pada penggerak lunak yang lebih canggih.

Pengaruh Pemanasan pada Struktur Kristal dan Sifat Kemagnetan Fe3O4 dari Pasir Besi

Jurnal Fisika dan Aplikasinya Vol 8, No 2 (2012)
Publisher : Jurnal Fisika dan Aplikasinya

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Abstract

Nano partikel magnetit telah disintesis dari pasir besi dengan menggunakan metode kopresitasi pada temperatur ruang dan dipanaskan. Struktur kristal, ukuran partikel dan sifat kemagnetan dikarakterisasi dengan XRD dan VSM. Hasil dari analisis didapatkan magnetit mengalami transisi fasa dan struktur pada temperatur 500C, parameter kisi bernilai (3,34 - 3,38) ˙A, ukuran partikel magnetite bernilai (11,48 - 13,45) nm dan nilai dari magnetik saturasi untuk sampel dengan temperatur sintering 100C dan 400C berturut-turut adalah 35 emu/g dan 65 emu/g.

Penelitian Komparasi Algoritma Klasifikasi Dalam Menentukan Website Palsu

Jurnal Teknologi Informasi, Ilmu Komputer dan Manajemen Vol 1 No 1 (2017)
Publisher : LPPM STMIK Widya Utama

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Abstract

Website counterfeit or phishing website is a crime in the virtual world whose popularity is increasing even in Indonesia until now in 2015. In this study we take on phishing websites dataset from UCI Repository as many as 2546 data by 30 variables used to determine the website is a phising website or not. Having obtained the data, the authors conducted a study to determine the most appropriate algorithms. Determination of the algorithms with comparisons between algorithms classification techniques. Based on some related research and the advantages of the algorithm, the authors took five algorithms to be tested, the algorithm Decission Tree (C4.5), Naive Bayes, KNN, Support Vector Machine and Neural Network. This study using a test of accuracy and AUC as well as different test parametric T-test. In each model, the authors divide the main data into five sections, and on each of the training data validation was done using K-Fold Cross Validation. The results of this study demonstrate that Neural Network algorithm and SVM into the most appropriate algorithm used by the average value of accuracy is 94 and the value AUC 0.9.

Perubahan Model Mental Siswa pada Materi Alat Optik melalui Experiential Learning

Jurnal Pendidikan: Teori, Penelitian, dan Pengembangan Vol 3, No 5: MEI 2018
Publisher : Graduate School of Universitas Negeri Malang

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Abstract

Abstract: The central goal of this research was to characterize the mental models of optical instruments expressed by students. The subject of this study were 35 students of class XI in SMA Negeri 1 Badegan. Mixed method embedded experimental model was conducted to probe the participant’s model mental. Data obtained through interviews and tests. The results reveal that the participants held five categories of mental models of optical instrument. The development of student’s model mental indicated by nearly half held a scientifically compatible model mental during and after studying Physics with Experiential Learning. Abstrak: Tujuan penelitian ini adalah untuk mengetahui model mental siswa SMA pada materi alat optik. Subjek penelitian adalah 35 siswa kelas XI SMA Negeri 1 Badegan. Penelitian menggunakan metode Mixed method embedded experimental model. Data diperoleh melalui tes dan wawancara. Hasil penelitian menunjukkan terdapat lima kategori model mental. Perubahan model mental siswa ditunjukkan dengan hampir setengah siswa di dalam kelas memiliki model mental yang sesuai dengan saintifik selama dan setelah pembelajaran Experiential Learning dilakukan.

Sintesis Kromium Ferit Dari Pasir Pantai dan Karakterisasi Awal Sensor Suhu

JPSE (Journal of Physical Science and Engineering) Vol 3, No 1 (2018): JPSE (Journal of Physical Science and Engineering)
Publisher : Universitas Negeri Malang

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Abstract

Ferrofluids for temperature sensor application become one of the important modern technology applications. Therefore, the development of the beach sand-based ferrofluids for temperature sensor becomes new and essential things for cutting off their production. In this research, the preliminary investigation of the temperature sensor is developed based on the chromium ferrite ferrofluids. The sample in powder and fluid were prepared by coprecipitation-sonochemical technique.   The powder sample which was characterized by XRD has the crystallite size of 10 nm with high purity. The preliminary investigation shows that the chromium ferrite ferrofluid has a good property as a candidate for temperature sensor application showing a good response on the temperature treatment

Investigasi Struktur dan Energi Band Gap Partikel Nano Tio2 Hasil Sintesis Menggunakan Metode Sol-Gel

JPSE (Journal of Physical Science and Engineering) Vol 3, No 1 (2018): JPSE (Journal of Physical Science and Engineering)
Publisher : Universitas Negeri Malang

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Abstract

TiO2 is a semiconductor material that widely applied in various fields due to its superiority both in terms of physical and chemical properties. In this study, the TiO2 nanoparticles was synthesized using sol-gel method. The synthesis of TiO2 nanoparticles was started by reacted TiCl3 with aquades and titrated with ammonium hydroxide and then followed by calcination process at 600 0C for 1.5 hours. The structural characteristics were investigated using XRD. The fungsional groups of the TiO2 nanoparticles were characterized by FTIR. The optical properties of the TiO2 nanoparticles were determined using UV-Vis spectrometer. The morphology of the sample was characterized using SEM. The results show that the TiO2 has structure as anatase phase. The data analysis using the Scherrer’s equation show that the particle crystallite size of is about of 9.77 nm. The energy band gap value of the TiO2 is 3.28 eV. Based on the SEM image, the agglomeration of the sample was formed with the average diameter of particle size of TiO2 is about 92 nm.

KAJIAN STRUKTUR KRISTAL DAN DIELEKTRISITAS NANOPARTIKEL MAGNETITE BERBASIS PASIR BESI DOPING Zn2+ HASIL SINTESIS METODE KOPRESIPITASI

Jurnal Sains Materi Indonesia Vol 13, No 2: FEBRUARI 2012
Publisher : BATAN

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Abstract

KAJIAN STRUKTUR KRISTAL DAN DIELEKTRISITAS NANOPARTIKEL MAGNETITE BERBASIS PASIR BESI DOPING Zn2+ HASIL SINTESIS METODE KOPRESIPITASI. Nanopartikel Fe3O4 berbasis pasir besi doping ion Zn2+ telah berhasil disintesis melalui metode kopresipitasi pada suhu rendah. Bahan-bahan yang digunakan adalah pasir besi sebagai bahan utama, ZnCl2, HCl dan NH4OH. Karakterisasi dilakukan menggunakan X-Ray Flourescence (XRF), X-Ray Diffraction (XRD) dan kapasitansi meter digital AD5822. Hasil uji XRF menunjukkan bahwa komposisi unsur sampel sesuai dengan stoikiometri. Identifikasi fasa menggunakan sotware High Score Plus dan DDView+PDF2 menunjukan bahwa seluruh sampel terbentuk dalam fasa spinel kubik. Hasil analisis refinement menggunakan sofware Reitica menunjukkan semakin banyak doping ion Zn2+ pada Fe3O4, nilai parameter kisi kristal juga meningkat dengan ukuran kristal berorde nanometer. Hal ini sebagai konsekuensi dari pengaruh ukuran jari-jari ion Zn2+ yang menggantikan ion Fe2+. Sementara hasil uji dielekrisitas menunjukkan dengan meningkatnya doping ion Zn2+ pada Fe3O4, nilai dielektrisitasnya juga meningkat. Mekanisme ini adalah fenomena polarisasi ionik sebagai akibat dari menurunnya volume kristal dan jarak antar atom, sehingga momen dipol semakin besar.

PROCEDURAL E-SCAFFOLDING IN IMPROVING STUDENTS’ PHYSICS PROBLEM SOLVING SKILLS

Unnes Science Education Journal Vol 7 No 2 (2018): July 2018
Publisher : Unnes Science Education Journal

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Abstract

The purpose of this study was to design scaffolding that is connected to an ICT system (e-scaffolding) which was implemented with blended learning to improve students’ physics problem solving skills (PSS). The research method used is Borg & Gall research method and the effectiveness test used is T-test in analyzing whether there are differences physics PSS in the experimental and control classes. This article describes scaffolding systems that focus in procedural types which using prompt questions and facts found during the implementation of this product. The results showed that the developed e-scaffolding was appropriate to be used for several examinations after being evaluated by experts and practitioners. In a limited implementation, e-scaffolding has proven not to be out of the social constructivist scope and adapted to the actual abilities of students. At effectiveness test, e-scaffolding is able to connect between students in solving problems both in synchronous and asynchronous collaboration. In addition, e-scaffolding is able to split problem categories that students are experts and beginners, giving shape to performance and increasing students’ physics PSS. So, it can be concluded that e-scaffolding has been successfully developed. Suggestions for further research have been presented in this article.

Peningkatan Ekstraksi Fitur Berbasis Scale Invariant Feature Transform Menggunakan Metode Multiscale Retinex Untuk Meningkatkan Jumlah Keypoint

Jurnal Teknologi Informasi, Ilmu Komputer dan Manajemen Vol 2 No 2 (2018): Vol 2 No 2 (2018)
Publisher : LPPM STMIK Widya Utama

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Abstract

The purpose of this research is to perform the improvement of feature extraction based on SIFT algorithm with MSR preprocessing step to increase the number of keypoint. Often in recognizing the SIFT algorithm pattern is affected by image quality. The better the recognizable image, the more number of keypoints it can get. For that need to do preprocessing stages so that the accuracy produced SIFT higher. In this study the researchers tried to combine SIFT algorithm with Multi-Scale Retinex (MSR) method. The MSR method is used because it has advantages in improving image quality in images that have less illumination (darkness). From the test results using MSE and PSNR the proposed method (MSR) is better than the previous methods. The average test result of number of keypoint without preprocessing is 1083.523, Constrast Stretching is 1093.797, CLAHE is 1105.891 and MSR is 1399.162. From this test it can be concluded that the SIFT combination with the preprocessing stages of Multi-Scale Retinex produces a good number of keypoints compared with other methods and without preprocessing stages.