Dc drift reduction in LiNbO3 optical modulators by decreasing the water content of vacuum evaporation deposited SiO2 buffer layers

1998 ◽  
Vol 37 (10) ◽  
pp. 2855 ◽  
Author(s):  
Masaru Shiroishi
1991 ◽  
Vol 4 (9) ◽  
pp. 473-475 ◽  
Author(s):  
K Imada ◽  
K Yoshiara ◽  
I Kawamata ◽  
F Uchikawa ◽  
S Utsunomiya ◽  
...  

1991 ◽  
Vol 9 (1) ◽  
pp. 92-100 ◽  
Author(s):  
W. Charczenko ◽  
P.S. Weitzman ◽  
H. Klotz ◽  
M. Surette ◽  
J.M. Dunn ◽  
...  

2021 ◽  
Vol 8 (2) ◽  
pp. 34-37
Author(s):  
Anang Lastriyanto ◽  
Silvi Astri Cahyani

Honey that has a moisture content above 22% should be done moisture reduction process. reduction of water content is done so that honey does not undergo fermentation and has a longer shelf life. One of the ways that can be used to reduce water content in honey is evaporation. Evaporation is of converting some of the water content in the material into steam by utilizing temperatures close to the boiling point of water. However, the minor content of honey, such as the diastase enzyme, is very sensitive to high temperatures. Therefore, vacuum evaporation is used so that the process uses a lower temperature to minimize the damage to the diastase enzyme. The research method was carried out in 3 stages, namely sampling, evaporation process, and sample testing. The results of this study indicate that the process of vacuum evaporation and vacuum cooling can change the proximate content of cassava honey to comply with SNI.


Author(s):  
N. Tempel ◽  
M. C. Ledbetter

Carbon films have been a support of choice for high resolution electron microscopy since the introduction of vacuum evaporation of carbon. The desirable qualities of carbon films and methods of producing them has been extensively reviewed. It is difficult to get a high yield of grids by many of these methods, especially if virtually all of the windows must be covered with a tightly bonded, quality film of predictable thickness. We report here a method for producing carbon foils designed to maximize these attributes: 1) coverage of virtually all grid windows, 2) freedom from holes, wrinkles or folds, 3) good adhesion between film and grid, 4) uniformity of film and low noise structure, 5) predictability of film thickness, and 6) reproducibility.Our method utilizes vacuum evaporation of carbon from a fiber onto celloidin film and grid bars, adhesion of the film complex to the grid by carbon-carbon contact, and removal of the celloidin by acetone dissolution. Materials must be of high purity, and cleanliness must be rigorously maintained.


Author(s):  
Joseph D. C. Peng

The relative intensities of the ED spots in a cross-grating pattern can be calculated using N-beam electron diffraction theory. The scattering matrix formulation of N-beam ED theory has been previously applied to imperfect microcrystals of gold containing stacking disorder (coherent twinning) in the (111) crystal plane. In the present experiment an effort has been made to grow single-crystalline, defect-free (111) gold films of a uniform and accurately know thickness using vacuum evaporation techniques. These represent stringent conditions to be met experimentally; however, if a meaningful comparison is to be made between theory and experiment, these factors must be carefully controlled. It is well-known that crystal morphology, perfection, and orientation each have pronounced effects on relative intensities in single crystals.The double evaporation method first suggested by Pashley was employed with some modifications. Oriented silver films of a thickness of about 1500Å were first grown by vacuum evaporation on freshly cleaved mica, with the substrate temperature at 285° C during evaporation with the deposition rate at 500-800Å/sec.


Author(s):  
Paul G. Kotula ◽  
C. Barry Carter

Thin-film reactions in ceramic systems are of increasing importance as materials such as oxide superconductors and ferroelectrics are applied in thin-film form. In fact, reactions have been found to occur during the growth of YBa2Cu3O6+x on ZrO2. Additionally, thin-film reactions have also been intentionally initiated for the production of buffer layers for the subsequent growth of high-Tc superconductor thin films. The problem is that the kinetics of ceramic thin-film reactions are not well understood when the reaction layer is very thin; that is, when the rate-limiting step is a phase-boundary reaction as opposed to diffusion of the reactants through the product layer. In this case, the reaction layer is likely to be laterally non-uniform. In the present study, the measurement of thin reaction-product layers is accomplished by first digitally acquiring backscattered-electron images in a high-resolution field-emission scanning electron microscope (FESEM) followed by image analysis. Furthermore, the problem of measuring such small thicknesses (e.g., 20-500nm) over lengths of interfaces longer than 3mm is addressed.


Author(s):  
Songquan Sun ◽  
Richard D. Leapman

Analyses of ultrathin cryosections are generally performed after freeze-drying because the presence of water renders the specimens highly susceptible to radiation damage. The water content of a subcellular compartment is an important quantity that must be known, for example, to convert the dry weight concentrations of ions to the physiologically more relevant molar concentrations. Water content can be determined indirectly from dark-field mass measurements provided that there is no differential shrinkage between compartments and that there exists a suitable internal standard. The potential advantage of a more direct method for measuring water has led us to explore the use of electron energy loss spectroscopy (EELS) for characterizing biological specimens in their frozen hydrated state.We have obtained preliminary EELS measurements from pure amorphous ice and from cryosectioned frozen protein solutions. The specimens were cryotransfered into a VG-HB501 field-emission STEM equipped with a 666 Gatan parallel-detection spectrometer and analyzed at approximately −160 C.


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