Peranan Fase Amorf Si3n4 Pada Nanokomposit Nc-tin/a-si3n4 Dalam Meningkatkan Kekerasan Dan Stabilitas Termal

The role of Si3N4 amorphous phase in nc-TiN/a-Si3N4 nanocomposites will be shown and compared with polycrystalline ZrN/Ni which has no such amorphous phase (non-composites). The presence of amorphous phase Si3N4 increases the hardness of film as well as the toughness of the bulk nanocomposites under indentation load. It has been observed that nc-TiN/a-Si3N4 nanocomposites films has higher thermal stability than ZrN/Ni polycrystalline films

Pembuatan Paduan (Ti1-xalx)n Dengan Teknik Plasma Cvd Dari Bubuk Alcl3, Gas N2 Dan H2, Serta Larutan Ticl4

    The substitution of Ti atoms by Al atoms in TiN lattice sites to form (Ti1-xAlx)N is clearly demonstrated by the coatings which were deposited on steel substrate and using plasma CVD technique. The presence of Al atoms in TiN lattice site is shown by means of XRD and EDX techniques: lattice parameters decreasing of TiN as the fraction of Al increases (XRD) and precipitation of hexagonal AlN phase (XRD) as the fraction of Al exceeding 0.8 (EDX). The hardness of these coating are just around 30 GPa, which is beyond the values reported in literatures

Prosedur Pengukuran Kekerasan Yang Benar Pada Nanokomposit Nc-tin/a-si3n4

Hardness of nc-TiN/a-Si3N4 nanocomposites which was determined by using two methods of measurements i. e. depth sensing method and remaining plastic indentation area that were magnified by using SEM (Scanning Electron Microscope) lie in the good agreement. The hardness value is not influenced by the biaxial and residual compressive stress. The measurement of the biaxial stress on the substrate shows a very small value of biaxial stress as well as the constant hardness and crystallite size against annealing temperature. Therefore, the reported hardness value here is theintrinsic value that depend on its microstructure properties

Extra-large crystal emulsion detectors for future large-scale experiments

Photographic emulsion is a particle tracking device which features the best spatial resolution among particle detectors. For certain applications, for example muon radiography, large-scale detectors are required. Therefore, a huge surface has to be analyzed by means of automated optical microscopes. An improvement of the readout speed is then a crucial point to make these applications possible and the availability of a new type of photographic emulsions featuring crystals of larger size is a way to pursue this program. This would allow a lower magnification for the microscopes, a consequent larger field of view resulting in a faster data analysis. In this framework, we developed new kinds of emulsion detectors with a crystal size of 600-1000 nm, namely 3-5 times larger than conventional ones, allowing a 25 times faster data readout. The new photographic emulsions have shown a sufficient sensitivity and a good signal to noise ratio. The proposed development opens the way to future large-scale applications of the technology, e.g. 3D imaging of glacier bedrocks or future neutrino experiments.Comment: Version accepted for publication in JINS

Pembuatan Polimer Lateks Emulsi Untuk Peningkatan Cbr Tanah Sub-grade Pada Konstruksi Jalan

Synthesize of emulsion polymer latex for sub-grade CBR improvement in the road construction. Latex polymerfor California Bearing Ratio (CBR) enhancement in sub-grade soil of road building has been prepared by emulsionpolymerizations technique. The prepared polymer then characterize by Fourier Transform Infrared (FTIR). Forapplication purpose, CBR test was done to the compacted polymer added-soil. The CBR test is done also for bothsoaked and unsoaked samples. It is found that our latex polymer is better then other imported latex polymer. For thelatex polymer, which is design to have Temperatur glass (Tg) around 9.8-19.6o, indicating the formation of C=O and -C-O-C- bonds at 1732-1736 cm-1 energy absorption as binder groups. CBR test results show that our latex polymer hasCBR value around 15-18 % compare to the soil without polymer binder

Polycrystalline thin-film transistors fabricated on high-mobility solid-phase-crystallized Ge on glass

Low-temperature formation of Ge thin-film transistors (TFTs) on insulators has been widely investigated to improve the performance of Si large-scale integrated circuits and mobile terminals. Here, we studied the relationship between the electrical properties of polycrystalline Ge and its TFT performance using high-mobility Ge formed on glass using our recently developed solid-phase crystallization technique. The field-effect mobility μFE and on/off currents of the accumulation-mode TFTs directly reflected the Hall hole mobility μHall, hole concentration, and film thickness of Ge. By thinning the 100-nm thick Ge layer with a large grain size (3.7 μm), we achieved a high μHall (190 cm2/Vs) in a 55-nm thick film that was almost thin enough to fully deplete the channel. The TFT using this Ge layer exhibited both high μFE (170 cm2/Vs) and on/off current ratios (∼102). This is the highest μFE among low-temperature (<500 °C) polycrystalline Ge TFTs without minimizing the channel region (<1 μm)

Analytic Tableaux for Simple Type Theory and its First-Order Fragment

We study simple type theory with primitive equality (STT) and its first-order fragment EFO, which restricts equality and quantification to base types but retains lambda abstraction and higher-order variables. As deductive system we employ a cut-free tableau calculus. We consider completeness, compactness, and existence of countable models. We prove these properties for STT with respect to Henkin models and for EFO with respect to standard models. We also show that the tableau system yields a decision procedure for three EFO fragments

Pengaruh Panjang Serat dan Tebal Papan Komposit Polyester Berpenguat Serat Lontar dan Serat Gewang terhadap Kekuatan Bending

ABSTRAK Pengembangan papan serat benar-benar potensial untuk Nusa Tenggara Timur memiliki iklim yang ideal ditumbuhi oleh tanaman berserat, termasuk dibuat pohon dan pohon palmyra yang sebagai bahan bangunan berkualitas spesifik seperti kepadatan, baru, kekuatan dan keawetannya. Penelitian ini dilakukan untuk mendapatkan pengaruh panjang serat dan tebal papan penguat komposit serat polyester palmyra dan serat yang dibuat untuk memaksa lentur. Variasi pada penelitian ini, yaitu panjang serat 1 cm, 2 cm dan 3 cm serta ketebalan spesimen yaitu 0,5 cm, 0,8 cm, 1 cm, dan 1,2 cm dengan fraksi volume 30%, orientasi serat arah sembarangan. Penelitian tentang metode pencetakan komposit adalah menggunakan metode hand lay up. Uji lentur dari spesimen dibuat sesuai dengan standar ASTM D790. Hasil uji kekuatan lentur menunjukkan bahwa spesimen dengan panjang 1 cm dan tebal serat 0,5 cm untuk serat dan serat gewang epigraph memiliki kekuatan lentur terendah MPa 11.12 dan 12.05 MPa. Sedangkan spesimen dengan serat panjang 3 cm dan tebal 1,2 cm untuk serat lontar dan serat gewang memiliki kekuatan lentur tertinggi yaitu 23,33MPa dan 18,21 MPa. Hasil pengujian menunjukkan bahwa serat terus menjadi panjang dan mendapat spesimen lebih tebal sehingga lentur daya bertambah. Hal ini karena panjang serat memiliki struktur yang lebih sempurna, sehingga ikatan antara serat panjang dan matriks memiliki struktur kristal yang tersusun sepanjang serat dan cacat internal yang panjangnya kurang serat. Hasil foto makro menunjukkan bahwa patahan getas dan debonding

High photoresponsivity in a GaAs film synthesized on glass using a pseudo-single-crystal Ge seed layer

Research to synthesize a high-quality GaAs film on an inexpensive substrate has been continuing for decades in the quest to develop a solar cell that achieves both high efficiency and low-cost. Here, we applied a large-grained Ge layer on glass, formed by Al-induced layer exchange, to an epitaxial template for a GaAs film. The GaAs film, grown epitaxially from the Ge seed layer at 520 °C, became a pseudosingle crystal (grain size > 100 μm) with high (111) orientation. Reflecting the large grain size, the internal quantum efficiency reached 70% under a bias voltage of 1.0 V. This value approaches that of a simultaneously formed GaAs film on a single-crystal Ge wafer and is the highest for a GaAs film synthesized on glass at a low temperature. The application of a Ge seed layer formed by layer exchange offers excellent potential to develop high-efficiency thin-film solar cells with III–V compound semiconductors based on low-cost glass substrates.This work was supported financially by the JSPS KAKENHI (No. 17H04918). The authors are grateful to Dr. Y. Tominaga (Hiroshima University) for helpful discussions and Professor N. Usami (Nagoya University) for assistance with the microwave photoconductivity decay measurement. Some experiments were conducted at the International Center for Young Scientists at NIMS and the Nanotechnology Platform at the University of Tsukuba