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"Ultra-precision machining is a promising solution for achieving excellent machined surface quality and sophisticated micro/nano-structures that influence the applications of components and devices. Further, given the ultrathin layer of material removed, it is a highly coupled process between cutting tool and material. In this book, scientists in the fields of mechanical engineering and materials science from China, Ukraine, Japan, Singapore present their latest research findings regarding the simulation and experiment of material-oriented ultra-precision machining. Covering various machining methods (cutting, grinding, polishing, ion beam and laser machining) and materials (metal, semiconductor and hard-brittle ceramics), it mainly focuses on the evaluation of the fundamental mechanisms and their implementation in processing optimization for different materials. It is of significant theoretical and practical value for guiding the fabrication of ultra-smooth and functional surfaces using ultra-precision machining."

"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."

"PT Nabisco Foods is a food industry which is facing quality problem, that is product overweight. Overweight percentage existing reaches 5,44 percent meanwhile company?s maximum taret for overweight is only 3 percent. Six Sigma is a comprehensive methodology for quality improvement which is directly eliminating the main special sources of problem with DMAIC (De_firie-MeaszIre-Analyze-improve-Coniro/) approach. Six Sigma concept is aimed to increase process capability, reduce variation between outputs and adjust them with the target.Determining product O with Reguler type as the main focuss, research scope is limited in mixing, forming dan baking area. Then the actual process capability is evaluated by measuring weight and thickness parameter of base cake. For weight parameter, level sigma is 5,04 dan 99,93 percent yield. These metric value indicates that the process capability for weight parameter is quite good. On the other hand, for thickness parameter, level sigma 3,45 and 97,42 percent yield are received which points that improvement focuss on process related to thickness parameter is needed. By analyzing actual process, the root causes with highest risk level are identiiied, one of them is the leak of correlation of temperature between oven zone. The outcome of using Taguchi method is the optimum setting that are I baking time in 6 menit, suhu zone 1,2 dan 3 subsequently 500, 610 and 650 F.For the last phase of Six Sigma., author recommend utilization of control chart form for monitoring process capability continuously with thickness of base cake as the parameter."

"Dalam rangka meningkatkan performa anoda litium titanat, penelitian ini difokuskan pada doping ion Ca2 untuk mensubtitusi ion Li membentuk Li4-xCaxTi5O12 dengan nilai x=0, 0.05, 0.075, dan 0.125 dengan menggunakan metode solid-state. Sumber ion Ca2 adalah CaCO3 yang berasal dari cangkang telur ayam yang sudah dibersihkan, dihaluskan dan dikeringkan. Dopant ini dikarakterisasi untuk mengetahui komponen fasa utama melalui pengujian XRD dan SEM-EDS. Serbuk sampel LTO pristine dan yang didoping dikarakterisasi dengan XRD, SEM-EDS, STA, dan FTIR. dan juga diuji performa elektrokimianya dengan EIS, CV dan CD. Hasil karakterisasi dopant CaCO3 dari cangkang telur menunjukkan komponen fasa utama CaCO3 dengan polimorf calcite, dengan morfologi butiran partikel halus teraglomerasi yang memiliki kemurnian tinggi. Karakterisasi serbuk sampel material anoda menggunakan uji XRD menunjukkan dopant Ca berhasil masuk kedalam struktur spinel LTO, dengan kadar penambahan maksimum x=0.05 dimana penambahan berlebih menghasilkan impuritas CaTiO3. Hasil SEM memperlihatkan semua sampel doping memiliki morfologi yang hampir serupa, partikulat teraglomerasi. Sampel LTO yang didoping ion Ca2 memiliki ukuran partikel yang lebih kecil jika dibandingkan dengan LTO tanpa doping. Peningkatan konduktivitas elektronik terlihat pada sampel yang didoping, dengan nilai hambatan terendah ditunjukkan oleh Li3.875Ca0.125Ti5O12 dengan Rct terendah yaitu 39.5 ?. Li3.875Ca0.125Ti5O12 juga memiliki initial discharge capacity tertinggi dengan nilai 168.2 mAh/g. Akan tetapi pada aplikasi rate tinggi, performa terbaik ditunjukkan oleh Li3.925Ca0.075Ti5O12 dengan kapasitas discharge 30.2 mAh/g pada 12 C, dimana persentasi retensi kapasitasnya sebesar 21.43 dibandingkan dengan kapasitas discharge pada rate 0.2 C.

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In order to improve the performance of Li4Ti5O12 LTO anode, this research was focused on Ca2 ion doping as substitute to Li ion to form Li4 xCaxTi5O12 with values of x 0, 0.05, 0.075, and 0.125 using solid state reaction. The Ca2 ion source was CaCO3 which synthesized from chicken eggshell that has been washed, grounded and dried. The dopant was characterized to determine the main phase component by XRD and SEM EDS. Pristine LTO and Ca doped LTO sample powder was characterized by XRD, SEM EDS, STA, FTIR and was also tested its electrochemical performance by EIS, CV and CD.

The CaCO3 dopant characterization results showed CaCO3 in calcite polymorph as the main phase, with agglomerated fine particulate morphology and high purity. Characterization of LTO sample powder with XRD revealed that dopant Ca successfully enter the structure of LTO spinel, with maximum addition level x 0.05, which excessive addition led to CaTiO3 impurity forming.

SEM result showed all Ca doped LTO have almost similar morphology, which was agglomerated particulate. Ca doped LTO samples have smaller particle size compared to pristine LTO. Electronic conductivity improvement was spotted at all of Ca doped LTO sample, with Li3.875Ca0.125Ti5O12 showed the lowest charge transfer resistance of 39.5 . Li3.875Ca0.125Ti5O12 also had the highest initial discharge capacity of 168.2 mAh g. Nevertheless, in high rate application, the best performance was showed by Li3.925Ca0.075Ti5O12 with discharge capacity of 30.2 mAh g at 12 C, which capacity retention percentage of 21.43 compared to discharge capacity at 0.2 C."