1,720,970 research outputs found
Pengaruh Perbedaan Tekanan terhadap Proses Pemolingan Bahan Piezoelektrik Pbzr0,52ti0,48o3 dengan Penambahan Polyvinylidine Flouride
No full textIt has been synthesized a piezoelectric ceramic material Plumbum Zirconate
Titanate (PZT) is the material that contains elements PbZr0,52Ti0,48O3. This
research was carried out by grinding, compacting with variations of pressure of
35.150 N/m2 and 49.210 N/m2, and heating at a temperature of 950oC for 4 hours
so-called solid state reaction. After the synthesis process has been done the
characterization materials using X-ray diffractometer (XRD) and Brunauer,
Emmet, Teller (BET). The result of identification using XRD shows that the
synthesis product had a tetragonal crystal structure of perovskite. The good PZT
will be crushed again with the addition of gram PVDF fraction of 1,5% and 2,5%
for PZT pressure of 35.150 N/m2 and 5% for PZT pressure of 49.210 N/m2. Then
proceed with the process of polling with the voltage 4 kV/mm using a high voltage
of source series of TV 14-21 inches. The success of the process of polling proved
by measurements of the piezoelectric constants using d33 meter. The results of the
highest piezoelectric constants obtained from PZT material piezoeletrik 49.210
N/m2 pressure is 61 x 10-12 C/N. The addition of PVDF on PZT reduce
piezoelectric’s constant value.79 HalamanSkripsi Sarjan
Sintesis Bahan Piezoelektrik Ramah Lingkungan Berbasis Bi0,5 Na0,5tio3 Menggunakan Metode Solid State Reaction dengan Penambahan Dopan Ta2o5
No full textThe research on synthesis of BNT piezoelectric material with addition dopant
Ta2O5have been carried out by using solid state reaction method. In this research,
samples were made by using these parameters, 4 hours millings, compaction on
5000 psi, calcination on 200oC and sintering on 950oC for 4 hours. Samples were
performed into four variations by doped 0%, 1.5%, 3%, 4.5%, 6% dan 15% of
Ta2O5. Every sample was characterized by XRD, LCR, and BET. Based on
characterized XRD, LCR, and BET it is obtained that BNT-Ta2O5 have optimals
work method at the moment of adding 3% of Ta2O5.64 HalamanSkripsi Sarjan
Sintesis BaTiO3 dari Campuran Ba(OH)2 dan TiO2 dengan Tambahan PbO
No full textPiezoelectric material can generate electric field in response to applied mechanical stress. Conversely, they can stretch and contract in response to an electric field. This material can be used for many applications such as transducer, microphone, ultrasound, and pressure gauge. Barium titanate is a ferroelectric material with piezoelectric properties that can be synthesized easily. The aim of this study is to synthesis barium titanate from mixture of Ba(OH)2 and TiO2, also observe its optimum temperature and the effect of PbO addition. The method of synthesis was solid-state reaction and sol-gel method, then the products were characterized with x-ray diffraction (XRD). Based on XRD analysis, the optimum temperature for both methods was 800°C. Addition of PbO to BaTiO3 in the solid-state reaction formed a compound with formula of Ba1-xPbxTiO3. The addition has changed diffraction pattern peak at 2θ and strengthened its tetragonal structure. The best result was obtained at x of 0.5 which will form a compound of Ba0.5Pb0.5TiO3
STRUKTUR MIKRO BAHAN PIEZOELEKTRIK BEBAS TIMBAL TITANAT-BARIUM TITANAT KALIUM NATRIUM NIOBATE HASIL SINTESIS DENGAN METODE REAKSI PADAT
Full text linkSTRUKTUR MIKRO BAHAN PIEZOELEKTRIK BEBAS TIMBAL TITANAT-BARIUM TITANAT KALIUM NATRIUM NIOBATE HASIL SINTESIS DENGAN METODE REAKSI PADAT. Telah dilakukan sintesis bahan keramik piezoelektrik Timbal Titanat-Barium Titanat-Kalium Natrium Niobate (BNT-BT-KNN )ramah lingkungan yakni bahan yang tidak mengandung unsur timbal dan merupakan bahan campuran antara bahan keramik Bismuth Natrium Titanat (BNT), Barium Titanat (BT) dan Kalium Natrium Niobate (KNN). Pada penelitian ini telah dilakukan sintesis BNT-BT-KNN dengan metode reaksi padat. Setelah proses sintesis strukturmikro bahan dikarakterisasi menggunakan X-Ray Diffractometer (XRD) dan Scanning Electron Mocroscope (SEM). Bahan BNT-BT-KNN yang disintesis memiliki rumus kimia (0,94-y)BNT-0,06BT-y KNN dengan harga y divariasikan dalam persentase mol sebesar 3 %, 6 % dan 8 %. Bahan campuran dipelet dengan tekanan sebesar 3500 psi dan di sinter pada suhu 1000 oC selama 4 jam. Bentuk pola difraksi BNT-BT-KNN yang terbentuk sama dengan bentuk pola difraksi yang di lakukan oleh peneliti sebelumnya. Dari pola difraksi bahan BNT-BT-KNN yang terbentuk mempunyai struktur kristal tetragonal dan terjadi pergeseran puncak sehingga mengidentifikasikan bahwa terjadi perubahan struktur tetragonal ke struktur rombohedral. Dari hasil SEM terlihat bahwa dengan kenaikan penambahan KNN terlihat bahan semakin berongga dengan ukuran yang semakin kecil dan lebih merata
ANALISIS KUALITATIF DAN KUANTITATIF FASA (Na0,5Bi0,5)TiO3 DENGAN TEKNIK DIFRAKSI SINAR-X MENGGUNAKAN METODE RIETVELD
Full text linkANALISIS KUALITATIF DAN KUANTITATIF FASA (Na0,5Bi0,5)TiO3 DENGAN TEKNIK DIFRAKSI SINAR-X MENGGUNAKAN METODE RIETVELD. Telah dilakukan analisis kualitatif dan kuantitatif fasa (Na0,5Bi0,5)TiO3 (NBT) dengan teknik difraksi sinar-X, metode Rietveld. Cuplikan NBT disintesis dengan metode reaksi padatan. Struktur mikro cuplikan diteliti dengan bantuan mikroskop elektron. Dalam penelitian ini ada enammodel masukan parameter least square, yakni model NBT1, NBT2, NBT3, NBT4, NBT5 dan NBT6. Hasil analisis menunjukkan bahwa model struktur yang paling cocok adalah model NBT3, yakni suatu model struktur dengan NBT terdiri dari dua fasa, yakni fasa tetragonal, grup ruang I4/mcm, No. 140, parameter kisi a = b = 5,485(1)Å, c = 7,772(2)Å, α=β=γ= 90°, fraksi berat 93,44 % dan fasa rombohedral, grup ruang R3c, No. 161-1, parameter kisi a = b = c = 3,908(1)Å, α=β=γ= 90,08(4), fraksi berat 6,56 %. Indeks reliabilitas Rwp =15,91 dan Rp = 11,86. Regangan kisi (ηT ) dan ukuran kristalit (DR) untuk sistem kristal tetragonal, sebesar 0,015 dan 150,00 Å. Sedangkan regangan kisi (ηT) dan ukuran kristalit (DR) untuk sistem kristal rombohedral, sebesar 0,016 dan 142,857 Å. Keberadaan unsur penyusun senyawa NBT di dalam cuplikan, yakni Bi, Na, Ti dan O, dibuktikan dari kurva cacahan hamburan sinar-X karakteristik terhadap energi dispersif. Secara dominan cuplikan NBT berfasa tetragonal ( > 90 %). Terbentuknya fasa rombohedral ( < 7 %) di dalam cuplikan NBT mungkin akibat ukuran butir dan distribusi tekanan di dalam prekursor pada saat pembuatan pelet tidak merata. Sehingga difusi atom-atom Bi, Na dan Ti pada saat proses sinter tidak merata di seluruh cuplikan
KARAKTERISASI PENGARUH DOPAN Mn PADA BAHAN KERAMIK PIEZOELEKTRIK LEAD ZIRCONIUM TITANATE (Pb[ZrxTi1-x]O3)
Full text linkKARAKTERISASI PENGARUH DOPAN Mn PADA BAHAN KERAMIK PIEZOELEKTRIK LEAD ZIRCONIUM TITANATE (Pb[ZrxTi1-x]O3). Telah dilakukan penelitian pembuatan bahan piezoelctrik Lead Zirconium Titanate (PZT) yang diberi bahan dopan Mn. Penambahan bahan dopan ini bertujuan untuk menaikkan sifat pizoelektrisitas dari PZT. Senyawa yang dianalisa pada penelitian ini adalah Pb[Zr0,5Ti0,5-xMnx]O3, dengan harga x (nominal) bernilai 0,05; 0,125; 0,25; 0,35. Hasil analisis menunjukkan bahan dengan dopan Mn ini diperoleh peningkatan suhu curie berkisar antara 15 sampai 35 oC. Namun konstanta dielektrikum menjadi turun dibandingkan dengan PZT murni
PENGARUH PENAMBAHAN BAHAN DOPAN TA2O5 PADA BAHAN PIEZOELEKTRIK RAMAH LINGKUNGAN (K0,5NA0,5)0,96LI0,04NO3 DENGAN MENGGUNAKAN SINTESIS METODE MOLTEN SALT
Full text linkABSTRAKTelah dilakukan penelitian tentang pengaruh penambahan bahan dopan Ta2O5 pada bahan piezoelektrik ramah lingkungan (K0,5Na0,5)0,96Li0,04NbO3(KNLN)dengan metode sintesis molten salt. Dalam penelitian ini dilakukan variasi persentase mol bahan dopan Ta2O5 sebesar 3%, 7%, 10% dan 12%. Sintesis dilakukan dengan parameter penggerusan selama 4 jam, kalsinasi pada suhu 2500C selama 1 jam, dan sintering pada suhu 9200C selama 4 jam. Berdasarkan analisis XRD dapat diidentifikasi bahwa struktur bahan piezoelektrik KNLNT (KNLN + dopan) pada penambahan 3% dan 7% cenderung ortorhombik, sedangkan pada penambahan 10% dan 12% cenderung tetragonal. Pada penambahan 7% mol Ta2O5 terjadinya penurunan nilai c/a yang tajam. Hal ini menunjukkan bahwa pada rentang komposisi inilah daerah motphotropic phase boundary berada. Hasil SEM menunjukkan pada penambahan dopan 3% ukuran partikel adalah 0,0884-0,7869 μm dan penambahan dopan 12% terjadi lonjakan tajam ukuran partikel yaitu sebesar 0,1563-1,5793 μm.AbstractResearch on the effect of the addition of dopant materials Ta2O5 on environmentally friendly piezoelectric materials (K0,5Na0,5)0,96Li0,04NbO3(KNLN) with molten salt synthesis method has been conducted. In this study, the mole percentage dopant materials varied by 3%, 7%, 10% and 12%. Synthesis was conducted with parameters: grinding for 4 hours, temperature calcination at 2500Cfor 1 hour, and sintering at a temperature of 9200C for 4 hours. Based on XRD analysis, it can be identified that the structure of the piezoelectric material KNLNT (KNLN + dopant) on the addition of 3% and 7% tend orthorhombic, while the addition of 10% and 12% tend to tetragonal. In addition of 7 % mol of Ta2O5, the c/a value decrese sharply. This value indicates that motphotropic phase boundary is located in this composition range. The SEM results show that at addition of 3% dopants the particle size is from 0.0884 to 0.7869 μm and at addition of 12% dopant the particle size increase sharply that to 0.15623 until 1.5793 μm.Â
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
