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"ABSTRAKPada penelitian ini dilaporkan investigasi mengenai efek dari eksposur faset kristal (001) TiO2 anatase terhadap aktivitas fotoelektrokatalitik dari fotoanoda yang terdiri dari film nanokomposit BiVO4/TiO2. Fotoanoda dibuat dengan mendeposisikan nanokomposit di atas permukaan kaca FTO melalui teknik doctor blade. Dalam penelitian ini, empat jenis morfologi TiO2 antase yaitu, nanospindel, nanocube, nanooctahedral, dan nanosheet disintesis melalui metode hidrotermal dengan penambahan directing agent yang berbeda. Selanjutnya, TiO2 hasil sintesis dikarakterisasi dengan menggunakan X-Ray Diffractometer (XRD), Transmission Electron Microscopy (TEM), Brunauer-Emmelt Tellers (BET), dan UV-Vis diffuse reflectance spectra (DRS). Berdasarkan hasil karakterisasi, puncak difraksi menunjukkan karakteristik untuk fase anatase murni dengan eksposure faset kristal (001) untuk nanospindel dan nanocube dan faset kristal (101) untuk nanocube dan nanooctahedral. Selain itu, respon fotoelektrokimia dari fotoanoda juga diukur menggunakan sistem 3 elektroda pada reaktor photocatalytic fuel cell (PFC) dan menghasilkan nilai densitas arus mencapai 0,0386 mA/cm2 untuk nanokomposit BiVO4/TiO2 nanosheet dan 0,0381 mA/cm2 untuk nanokomposit BiVO4/TiO2 nanospindle. Menggunakan sistem PFC ini, degradasi rhodamin B yang diperoleh adalah sebesar 23,15% untuk nanokomposit BiVO4/TiO2 nanosheet dan 30,58% untuk nanokomposit BiVO4/TiO2 nanospindle selama 3 jam reaksi.

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ABSTRACTThis work reports an investigation on the effect of exposing (001) crystal facet of anatase TiO2 to photoelectrocatalytic activity of photoanode composed of TiO2/BiVO4 nanocomposite film. Here, the photoanode was fabricated by depositing the nanocomposite on the surface of FTO via doctor blade technique. In this study, four different types of anatase TiO2 morphologies, i. e. nanospindle, nanocube, nanooctahedra, and nanosheet were synthesized via hydrothermal method in the presence of various directing agents. Furthermore, the as-prepared TiO2 was characterized using X-Ray Diffractometer (XRD), Transmission Electron Microscopy (TEM), Brunauer-Emmelt-Tellers (BET), and UV-Vis diffuse reflectance spectra (DRS). Based on the result, the diffraction peaks revealed characteristic for the pure anatase phase with exposure (001) crystal facet for nanospindle and nanosheet and (101) crystal facet for nanocube and nanooctahedra. Additionally, photoelectrochemical response of the photoanode was also evaluated using a three-electrode system on the photocatalytic fuel cell (PFC) reactor and exhibited a significantly high current density value of 0.0386 mA/cm2 and 0.0381 mA/cm2 for TiO2 nanosheet/BiVO4 and TiO2 nanospindle/BiVO4 nanocomposite. Using this PFC system, the degradation of rhodamine B were obtained 23.15% and 30.58% for TiO2 nanosheet/BiVO4 and TiO2 nanospindle/BiVO4 nanocomposite for 3 hours reaction time. "

"This book combines a model reduction technique with an efficient parametrization scheme for the purpose of solving a class of complex and computationally expensive simulation-based problems involving finite element models. These problems, which have a wide range of important applications in several engineering fields, include reliability analysis, structural dynamic simulation, sensitivity analysis, reliability-based design optimization, Bayesian model validation, uncertainty quantification and propagation, etc. The solution of this type of problems requires a large number of dynamic re-analyses. To cope with this difficulty, a model reduction technique known as substructure coupling for dynamic analysis is considered. While the use of reduced order models alleviates part of the computational effort, their repetitive generation during the simulation processes can be computational expensive due to the substantial computational overhead that arises at the substructure level. In this regard, an efficient finite element model parametrization scheme is considered. When the division of the structural model is guided by such a parametrization scheme, the generation of a small number of reduced order models is sufficient to run the large number of dynamic re-analyses. Thus, a drastic reduction in computational effort is achieved without compromising the accuracy of the results. The capabilities of the developed procedures are demonstrated in a number of simulation-based problems involving uncertainty."

"Studi komputasi adalah studi yang ditentukan dari perhitungan struktur elektronik berupa material, seperti Fe, Ni, dan Co. Struktur kristal berupa material Fe, Ni, dan Co yang dikomputasikan adalah Fe3Ni2 dan Fe6Ni3Co. Struktur Fe6Ni3Co yang didapatkan dengan mengganti Ni pada Fe3Ni2 dengan Co. Studi ini telah dilakukan dengan menggunakan Density Functional Theory (DFT) melalui metode atomistik, optimasi geometri, dan analisis konstanta elastis. Metode atomistik menunjukkan bahwa struktur kristal yang berbentuk tetragonal dan kelompok ruang P4/mmm. Optimasi geometri dilakukan dengan menggunakan energy cutoff sebesar 300 eV terhadap struktur kristal yang berbentuk tetragonal dengan parameter kisi (a, b, c) adalah (10, 10, 1) dalam satuan Å. Analisis konstanta elastis menghasilkan besaran Cij terdiri dari i adalah pola regangan secara masing-masing sebanyak 6 dan j adalah amplitudo sebanyak 6. Cij berguna untuk menentukan konstanta elastis beserta jenisnya, antara lain modulus elastisitas, modulus bulk, modulus geser, kompresibilitas, dan rasio poisson serta berguna untuk menentukan kondisi stabilitas dari Fe3Ni2 dan Fe6Ni3Co.

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Computational studies are studies that are determined from the calculation of the electronic structure of materials, such as Fe, Ni, and Co. The crystal structures in the form of Fe, Ni, and Co materials which are computed are Fe3Ni2 and Fe6Ni3Co. The Fe6Ni3Co structure obtained by replacing Ni in Fe3Ni2 with Co. This study was carried out using Density Functional Theory (DFT) through atomistic method, geometry optimization, and elastic constant analysis. Atomistic method shows that the crystal structure is tetragonal and the space group is P4/mmm. Geometry optimization was carried out using a cutoff energy of 300 eV for a tetragonal crystal structure with lattice parameters (a, b, c) of (10, 10, 1) in Å units. Analysis of the elastic constant produces the amount Cij consist of i is the pattern of strain as many as 6 each and j is the amplitude of 6. Cij is useful for determine the elastic constants and their types, including modulus of elasticity, bulk modulus, shear modulus, compressibility, and poisson’s ratio as well useful to determine the stability conditions of Fe3Ni2 and Fe6Ni3Co."

"This book discusses the main mechanical features of masonry buildings and the peculiarities that affect their structural behaviour. It also examines technical information regarding accidents that have occurred in recent years in the Metropolitan Region of Recife, along with the historical records of these events, followed by indications of the causes for the collapse.The book offers extensive experimental results that make it possible to identify the contribution of several mortar rendering layers to the load capacity of the tested specimens. Lastly, it explores the factors that influenced the load capacity of the tested specimens."

"Sel surya perovskite berbasis timbal menunjukkan efisiensi dan stabilitas yang tinggi dengan metode sintesis mudah dan murah, namun penggunaan timbal sangat dikhawatirkan karena tingkat toksisitas tinggi dan dapat mencemari lingkungan. Baru-baru ini disintesis bismuth perovskite yang stabil, non-toksik dan dapat disintesis dengan metode sederhana pada temperatur rendah namun persen efisiensinya hanya mencapai 0,19%. Berbagai riset membuktikan bahwa titania anatase dengan persen eksposur (001) yang besar mampu meningkatkan arus listrik, tegangan, meningkatkan injeksi elektron dan memperkecil rekombinasi. Sehingga pada penelitian ini, disintesis TiO₂ nanopartikel dengan tingkat pemaparan faset (001) berbeda menggunakan capping agent fluorin dan mendapatkan persentase faset (001) menurut karakterisasi XRD 17% , 18% dan 23% dan menurut karakterisasi raman 12% , 14% dan 25%. Menurut hasil dari karakterisasi dengan UV-DRS seiring dengan penambahan volume HF reflektan dari TiO2 di daerah sinar UV meningkat. Dari hasil perhitungan, didapatkan energi celah pita untuk variasi HF 5 ml, HF 10 ml dan HF 15 ml adalah 3,25 eV; 3,25 eV dan 3,3 eV.

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Lead-based perovskite solar cells exhibit high efficiency and stability with an easy and inexpensive synthesis method, but the use of lead is a great concern because of its high toxicity and pollution. Recently bismuth perovskite with stable, non-toxic and simple synthesis low temperature method has been synthesized but the efficiency is only 0,19%. Various studies have shown that anatase titania with a large percentage of exposure (001) facet can increase electric current, voltage, electron injection and reduce recombination. In this study, TiO₂ nanoparticle were synthesized with different facet (001) exposure using fluorine as capping agents and obtained (001) facet percentage according to XRD characterization of 17%, 18% and 23% and according to raman characterization of 12%, 14% and 25%. According to UV-DRS characterization along with the addition of the volume of HF reflectant from TiO2 in the UV light region increases. From the calculation results, band gap energy for 5 ml HF variation, 10 ml HF and 15 ml HF is 3.25 eV; 3.25 eV and 3.3 eV."