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"Pada penelitian ini telah dilakukan sintesis nanostruktur TiO2 melalui proses sol- gel dengan variasi pengaruh surfaktan, metodologi, waktu kalsinasi dan suhu kalsinasi dari larutan TiOSO4 hasil ekstraksi Ilmenit (FeTiO3) yang merupakan produk sampingan dari proses mineral dressing bijih timah (cassiterit) di pulau Bangka. Karakterisasi XRD dilakukan untuk mengukur besar ukuran kristalit nanostruktur TiO2 yang dihasilkan. Dari hasil perhitungan besar ukuran kristalit diperoleh hasil Sampel P-25 Degussa memiliki ukuran Kristalit 21,08 nm diikuti dengan sampel penambahan surfaktan F127+TEOS 12 nm, penambahan surfaktan Dextrin 9,45 nm, tanpa penambahan surfaktan 5,71 nm, penambahan surfaktan F127 4,95 nm. Setelah itu dilakukan karakterisasi UV-Vis untuk mengetahui Energi Celah pita untuk memastikan nanostruktur TiO2 tersebut merupakan material semikonduktor, hasil yand diperoleh dari perhitungan yang mempunyai energi celah pita tertinggi adalah sampel TEOS 3,8 eV, diikuti oleh sampel Dextrin 3,28 eV, sampel F127 3,2 eV, sampel P-25 Degussa 3,19 dan sampel tanpa surfaktan 3,19 selanjutnya karakterisasi menggunakan PSA untuk mengetahui ukuran dan distribusi partikel sampel dengan ukuran partikel terbesar adalah sampel sampel F127+TEOS yakni 1840 nm diikuti sampel tanpa penambahan surfaktan 858,3 nm, sampel F127 530nm, dan sampel Dextrin 92,8nm. Dan detil struktur dan morfologi diperoleh dari hasil karakterisasi SEM, diperoleh struktur spheroida pada sampel Dextrin dan berukuran nano.

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In this study has been conducted through the synthesis of nanostructured TiO2 sol-gel process with surfactant variation influences, methodology, calcination time and calcination temperature of the extraction solution TiOSO4 ilmenite (FeTiO3) which is a by product of the process mineral ore dressing (cassiterit) on the Bangka Island . XRD characterization performed to measure the size of the resulting TiO2 nanostructured crystallites. From the calculation of the crystallite size of the obtained results Sample P-25 Degussa has Crystallite size of 21.08 nm followed by sample the addition of surfactant F127 + TEOS 12 nm, the addition of surfactant dextrin 9.45 nm, without the addition of surfactant 5,71 nm, the addition of surfactant F127 4.95 nm. After that UV-Vis characterization to determine the energy band gap to ensure nanostructured TiO2 is a semiconductor material, were associated with the results obtained from the calculations that have the highest energy band gap of 3.8 eV is a sample of TEOS, followed by dextrin samples 3.28 eV, sample F127 3.2 eV, sample P-25 Degussa 3.19 and samples without surfactant. further characterization using PSA to determine particle size and distribution of the sample with the largest particle size of a sample is a sample F127 + TEOS followed the 1840 nm sample without the addition of surfactant 858.3 nm, 530nm F127 samples, and samples dextrin 92.8 nm. And the detailed structure and morphology obtained from SEM characterization results, obtained on samples dextrin spheroida structures and nano-sized."

"ABSTRAKA natural-based nanocomposite film consisting of chitosan, montmorillonite (MMT) and cashew nut shell liquid (CNSL) was synthesized. The nanocomposite was prepared by mixing a suspension of clay particles (filler, MMT) with a solution containing chitosan as the macroscopic polymer matrix. In this study, it was proposed that non-ionic long-chain alkylmolecules with possible interact ions with the amine group of chitosan could be used as a plasticizer. As a natu-ral source for these compounds, an extract of CNSL was used. A series of chitosan/MMT com-posite samples containing two different clay contents and a sample with an additional CNSL were prepared. FTIR spectroscopy of the nanocomposite films indicated that, by addition of CNSL, amide groups of the chitosan are probably less attached and have more space for vibration. CNSL seems to provide intermolecular spaces between the chitosan molecules. Atomic force microscopy (AFM) analysis showed that the composite containedparticles measuring 100 nm or less, which confirmed that the nanocomposite had been successfully produced by this method. Addition of CNSL as plasticizer improved the tensile strength by 10% and the elastic modulus by almost 18%. Cell growth was observed on all the nanocomposite samples studied."

"Nanocomposite thin films consisting of titanium oxide, or TiO2, nanoparticles embedded in apolymer matrix represent a new class of potential materials for optoelectronic applications such as optical switches, waveguides, high refractive indices and non-linear optical devices. Among the various processing techniques under development for these nanocomposites, the in situ sol−gel process is known to be versatile as it enables control of the inorganic-organic interaction at various molecular, nanometer, and micrometer scales. However, the sol−gel process has a major limitation, which is the low crystallinity in the resulting TiO2 phase due to relatively low processing temperatures. Therefore, the current research is aimed at investigating the nanostructural evolution of theTiO2 crystallite during the in situ sol−gel process to gain a better understanding of the mechanisms responsible for the largely amorphous nature of TiO2 nanoparticles. For this purpose, two sol−gel parameters, i.e., the hydrolysis ratio (Rw) and pH value of the TiO2 precursor solution were varied. On the basis of XRD and FTIR analyses, it was found that the largely amorphous TiO2 state is related to the fast development of stiff Ti−OH networks during the hydrolysis and condensation stag es of the sol−gel process, and concurrently worsened by the formation of the rigid PMMA matrix upon thermal annealing."

"Nanofluida adalah jenis fluida yang sedang dikembangkan yang memiliki sifat konduktivitas yang lebih tinggi dibandingkan dengan air. Penelitian lebih lanjut diperlukan agar fluida baru ini dapat diaplikasikan secara efektif dan efisien. Tujuan dilakukannya pcnelilian ini adalah mempelajari pengamh penambahan partikel nano pada air terhadap nilai koefisien gesek jika Huida ini dialirkan pada pipa lurus. Penelitian dilakukan dengan cara mengalirkan fluida air dan nanofluida A1103 dcngan menvariasikan kecepatan aliran pada pipa lums berukuran 4 mm, 8 mm, dan 17 mm yang kemudian diukur nilai perbedaan tekanan dan debilnya. Hasil penelitian menunjukkan bahwa nilai koefisien gesek aliran nanofluida A1203 sedikit lebih kecil dibandingkan dengan aliran air pada aliran turbulen.

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Nanofluid is a kind of the fluid that is being developed which has higher conductivity rather than the water. It needs advance research in studying the effects of the adding the nano particle to water, due to the friction coefficient when this fluid flows in straight pipe. This research done by flowing the water and nanofluid A1203 , with variation of flow velocity in different straight pipe which has diameter 4 mm, 8 mm, and I 7 mm then measure the head loss and capacity. The results showed that the friction coefficient of nanofluid al203 flow less than the water at the turbulent flow."

"Sebuah penelitian sistematis telah dilakukan untuk mengetahui penyebab utama rendahnya tingkat kristalinitas nanopartikel titania (TiO2) di dalam nanokomposit TiO2−PMMA hasil proses sol−gel. Dari hasil investigasi diketahui bahwa fasa TiO2 amorfus di dalam nanokomposit disebabkan oleh pembentukan cepat dari jaringan kaku Ti-OH selama tahapan hidrólisis dan kondensasi, yang diperburuk dengan efek perangkap dari matrik PMMA. Sebuah metode kombinasi pra-anil dan pasca-hidrotermal berhasil meningkatkan tingkat kristalinitas fasa TiO2 secara signifikan , dengan tetap mempertahankan integritas matrik polimer di dalam nanokomposit. Analisis evolusi nano struktural TiO2 dalam nanokomposit dilakukan dengan pengujian XRD, spektroskopi FTIR dan TEM. Peningkatan kristalinitas nanopartikel TiO2 meningkatkan sifat-sifat optis linier dan nonlinier lapisan tipis transparan nanokomposit TiO2−PMMA

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A systematic investigation has been conducted to understand the mechanisms responsible for the low nanocrystallinity of TiO2 nanoparticles in sol−gel derived TiO2 −PMMA nanocomposites. On the basis of investigation, it is found that the largely amorphous TiO2 state is caused by the fast development of stiff Ti−OH networks during hydrolysis and condensation, worsened by the PMMA entrapment effect. A combined method involving a pre-annealing and a post -hydrothermal treatment has been successfully devised to enhance TiO2 nanocrystallinity, while maintaining the integrity of polymer matrix. The nanostructural evolution of TiO2 in nanocomposites were carried out with x-ray diffraction, Fourier Transfor Infra-Red (FTIR) spectroscopy and High -Resolution Transmission Microscope (HRTEM). The functional properties of the TiO2−PMMA nanohybrids have been correlated to their nanostructures, where both linear and nonlinear optical responses are shown to increase with the enhancement of TiO2 nanocrystallinity."

"Tujuan penelitian ini adalah melihat pengaruh aplikasi nano filled coating agent terhadap kekuatan tarik diametral semen ionomer kaca yang terkontaminasi saliva buatan. Spesimen direndam didalam aquabides selama 1 jam, 1 hari dan 1 minggu dengan suhu 37oC. Uji analisis statistik menggunakan t test tidak berpasangan.Hasil penelitian didapatkan pada perendaman 1 jam p= 0.051 dan 1 hari p=0,528 (P>0,05), sedangkan pada 1 minggu p=0.030 (p<0,05). Dapat disimpulkan bahwa aplikasi nano filled coating agent pada semen ionomer kaca yang terkontaminasi saliva buatan, sampai 1 hari dapat memberikan perubahan yang tidak bermakna pada nilai kekuatan tarik diametral.

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The purpose of this study is to see the influence of nano-filled coating agent applications for diametral tensile strength of GIC contaminated with artificial saliva. Specimens were stored in aquabides for 1 hour, 1 day and 1 week at 37 °C. Test analysis using non-paired t test.

The results obtained at 1 hour immersion p = 0051 and 1 day p = 0.528 (P> 0.05), whereas at 1 week p = 0030 (p <0.05). It can be concluded that the application of nano-filled coating agent on GIC contaminated with artificial saliva, until one day may provide a non-significant change in DTS values​​."

"Surface Mechanical Attritition Treatment adalah salah satu proses fabrikasi nano materialdengan cara memberikan deformasi mekanis strain-induced pada permukaan material.Penelitian ini memberi perlakuan SMAT pada stainless steel AISI 304 yang merupakanaustenitic stainless steel. Deformasi yang diperlakukan pada permukaan material akanmenghasilkan gradien regangan di seluruh bagian material. Perbedaan regangan dan strainrate mempengaruhi struktur yang terjadi. Semakin tinggi regangan yang diberikan (semakindekat dengan permukaan) menghasilkan butir yang lebih halus hingga skala nanometer. Dansebaliknya, semakin rendah regangan yang dialami maka akan dihasilkan butir yang kasar..Proses SMAT pada baja juga dapat menghasilkan transformasi fasa dari austenit kemartensit. Analisis XRD menunjukkan peningkatan kandungan martensit pada lapisan yangterkena regangan tinggi. Pengamatan TEM menunjukkan transformasi martensit terjadidengan dua mekanisme yaitu dari austenit yang berstruktur kristal FCC () menjadi martensityang berstruktur kristal HCP (ε) dan dari austenit yang berstruktur kristal FCC () menjadimartensit yang berstruktur kristal BCC (α’). Transformasi ini mengikuti arah dan hubungankristalografi Kurdjumov-Sachs (K-S) orientation yaitu 〈1-10〉γ//〈112-0〉ε//〈11-1〉α. Sementarapada bagian yang terkena regangan lebih rendah tetap mengandung fasa austenit.Kombinasi dari butir halus dan kasar serta austenit dan martensit pada material yang samamemungkinkan untuk mendapatkan material yang kuat sekaligus tangguh. Butir halus danfasa martensit pada permukaan akan meningkatkan kekerasan material, sementara butir kasardan fasa austenit pada bagian lebih dalam akan mempertahankan keuletan material.

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Surface Mechanical Attritition Treatment is one of nano material fabrication method which

done by applying strain-induced mechanical deformation on the surface. This research treated

stainless steel AISI 304 which is austenitic stainless steel type, with SMAT. The deformation

cause strain gradient through out the sample. Strain level differences give effect to material

structure. Higher strain which happen closely to the surface region, result in finer grain up to

nano scale, while lower strain cause more coarse grain.

SMAT on stainless steel also could cause phase transformation from austenite to martensite.

XRD analysis showed increase of martensite content on higher strain-affected layer. TEM

observations showed martensite transformation by two mechanism, austenite with FCC

crystal structure () to martensite with HCP crystal structure (ε) and austenite with FCC

crystal structure () to martensite with BCC crystal structure (α’). This transformation are

following crystalographic orientation relationship of Kurdjumov-Sachs (K-S), 〈1-10〉γ//〈112-

0〉ε//〈11-1〉α. While on the other region that less-affected by strain still contain austenite

phase.

Combination of fine grain-coarse grain and austenite-martensite phase on the same material

could result in higher properties material since it could has high strenght and high toughness.

Fine grain and martensite phase on the surface will increase the hardness of material, while

coarse grain and austenite phase on deeper layer will increase the ductility of material."

"Potensi gas hidrogen untuk diimplementasikan sebagai pembawa energi tanpa emisi sangat menjanjikan. Namun ada beberapa kendala yang harus dihadapi dalam pengimplementasiannya, yakni pengembangan teknologi penyimpanan gas hidrogen. Penyimpanan gas hidrogen dalam suatu adsorben karbon nanostruktur seperti carbon nanotube menjadi salah satu pilihan untuk dapat meningkatkan kapasitas penyimpanannya. Namun, banyaknya penelitian eksperimen yang tidak memberikan hasil yang reproducible menyebabkan perlunya ada pengembangan penelitian teoritis adsorpsi gas hidrogen dengan pendekatan termodinamika molekuler. Dengan kalkulasi struktur elektronik ab initio, energi potensial interaksi antar molekul gas hidrogen diestimasi sebesar 0,099 kcal/mol dan antara gas hidrogen dengan carbon nanotube diestimasi sebesar 1,057 - 1,142 kcal/mol. Energi potensial tersebut direpresentasikan ke dalam persamaan nilai parameter potensial klasik sebagai fungsi dari diameter carbon nanotube agar didapatkan model potensial yang paling presisi. Setelah mendapatkan nilai-nilai parameter potensial interaksinya, simulasi dinamika molekuler dilakukan dengan ensemble canonical untuk menganalisa adsorpsi gas hidrogen pada permukaan luar carbon nanotube. Dari hasil pengolahan data simulasi dinamika molekuler, didapatkan bahwa kalor isosterik berkurang dari 1,6 kcal/mol hingga menjadi 0,2 kcal/mol pada kondisi permukaan adsorben jenuh. Hasil ini cukup sesuai dengan hasil penelitian eksperimental literatur lainnya.

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The potency of hydrogen gas to be implemented as energy carrier with zero emission is very promising. Unfortunately, there are still crucial problems on its implementation, one of them is the development of hydrogen storage technology. Storing hydrogen gas on nanostructured carbon adsorbent could be an alternative to improve the storage capacity. However, the fact that there were so many experimental researches that couldn?t provide reproducible results creates a need to develop theoritical research on hydrogen gas adsorption on carbon nanotube using moleculer thermodynamics approach.

Using ab initio electronic structure calculations, The interaction potential energies between hydrogen molecules were estimated to be 0.099 kcal/mol and between hydrogen molecule and the outer surface of carbon nanotube were estimated to be 1.057 - 1.142 kcal/mol. The potential energies then were represented into an equation of potential parameter as a function of carbon nanotube diameterin order to get the most precise interaction potential model. Molecular dynamics simulations were performed on canonical ensemble to analyze hydrogen gas adsorption on outer surface of carbon nanotube.

From our calculations results, the isosteric heat of hydrogen physical adsorption on carbon nanotube were estimated to be 1.6 kcal/mol and decreased to 0.2 kcal/mol on saturated surface condition. This results are acceptable with some previous experimental researches results."

"Nanopartikel hybrid oksida besi/oksida tembaga/oksida seng telah disintesis dengan menggunakan metode sol-gel untuk tiga variasi molar. Seluruh sampel dikarakterisasi dengan spektroskopi X-Ray Diffraction, Field Emission Scanning Electron Microscopy, Vibrating Sample Magnetometer, Energy Dispersive X-Ray, Ultraviolet-visible Reflectance dan Fourier-Transform Infrared. Nanopartikel hybrid yang dihasilkan menunjukkan karakteristik feromagnetik dengan morfologi yang merupakan gabungan spherical-like dari oksida besi dan oksida seng dan clews-like dari oksida tembaga. Keempat unsur penyusunan nanopartikel hybrid hadir dalam bentuk ikatan Zn-O, Fe-O dan Cu-O dengan kehadiran fase dan struktur tunggal dari inverse cubic spinel magnetite, hexagonal wurtzite oksida seng dan monoclinic oksida tembaga. Celah energi nanopartikel hybrid cenderung turun dengan berkurangnya rasio molar oksida seng yang berhubungan dengan peningkatan kuantitas oksida besi dan oksida tembaga. Kondisi optimum aktivitas fotokatalitik nanopartikel hybrid dalam mendegradasi methylene blue dengan pemaparan cahaya ultraviolet diperoleh pada kondisi basa untuk pH 13. Nanopartikel hybrid dengan rasio molar 1:1:5 mampu menghasilkan degradasi maksimum dengan laju degradasi yang lebih tinggi dibandingkan nanopartikel oksida seng. Hole ditemukan sebagai spesies yang berperan aktif dalam aktivitas fotokatalitik nanopartikel hybrid dalam mendegradasi methylene blue.Iron oxide/cuprix oxide/zinc oxide hybrid nanoparticles with three variation of molar ratio have been synthesized using sol-gel methods. All samples were characterized by X-Ray Diffraction, Field Emission Scanning Electron Microscopy, Vibrating Sample Magnetometer, Energy Dispersive X-Ray, Ultraviolet-visible Reflectance and Fourier-Transform Infrared Spectroscopies. The resulting hybrid nanoparticles show ferromagnetic behaviour and have combination of spherical-like of iron oxide and zinc oxide morphologies with clews-like of cuprix oxide morphology. The four elements of the hybrid nanoparticles present in the form of Zn-O, Fe-O and Cu-O bonds and form individual crystal structures and phases of cubic inverse spinel of iron oxide, hexagonal wurtziteof zinc oxide and monoclinic of cuprix oxide. Energy gap of the hybrid nanoparticles tend to shift to lower energy that associates with increasing quantity of iron oxide and cuprix oxide with decreasing zinc oxide molar ratio. Optimum condition for photocatalytic activity of the hybrid nanoparticles in degrading methylene blue under ultraviolet light irradiation is obtained under alkaline conditions for pH 13. Hybrid nanoparticles with a molar ratio of 1:1:5 is able to produce the maximum degradation with higher degradation rate than zinc oxide nanoparticles. Hole found as species that plays an active role in photocatalytic activity of the hybrid nanoparticles to degrade methylene blue."