Chemical Transport Deposition of Purified Poly-Si Films from Metallurgical-grade Si Using Subatmospheric-pressure H2 Plasma

2010 ◽  
Vol 1245 ◽  
Author(s):  
Kiyoshi Yasutake ◽  
Hiromasa Ohmi ◽  
Hiroaki Kakiuchi
Keyword(s):  
Infrared Absorption ◽  
Transport Process ◽  
Chemical Transport ◽  
The Other ◽  
Determination Limit ◽  
Subatmospheric Pressure ◽  
Metal Impurities ◽  
Acceptable Range ◽  
Si Films ◽  
Absorption Measurements

AbstractPurified Si film is prepared directly from metallurgical-grade Si (MG-Si) by chemical transport using subatmospheric-pressure H2 plasma. The purification mechanism is based on the selective etching of Si by atomic H. Since most metals are not etched by H, this process is efficient to reduce metal impurities in Si films. It is demonstrated that the concentrations of most metal impurities (Fe, Mn, Ti, Co, Cr, Ni, etc.) in the prepared Si film are in the acceptable range for applying it to solar-grade Si (SOG-Si) material, or below the determination limit of the present measurements. On the other hand B and P atoms, which make volatile hydrogen compounds such as B2H6 and PH3, are difficult to eliminate by the present principle. From the infrared absorption measurements of the etching product produced by the reaction between H2 plasma and MG-Si, it is found that the main etching product is SiH4. Therefore, a remote-type chemical transport process is possible to produce SiH4 gas directly from MG-Si. Combining other purifying principle (such as a pyrolysis filter), this process may have an advantage to eliminate B2H6 and PH3 from the produced SiH4 gas.

Comparative Surface Imaging Study of Multifocal Diffractive Intraocular Lenses

2021 ◽  
Author(s):  
Hyeck Soo Son ◽  
Jung Min Lee ◽  
Ramin Khoramnia ◽  
Chul Young Choi
Keyword(s):  
Imaging Study ◽  
The Other ◽  
Intraocular Lenses ◽  
Optical Surface ◽  
Diffractive Optic ◽  
Atomic Force ◽  
Acceptable Range ◽  
Different Types ◽  
Concentric Pattern

Abstract Purpose To analyse and compare the surface topography and roughness of three different types of diffractive multifocal IOLs. Methods Using scanning electron microscope (SEM, Inspect F, 5.0 KV, maximum magnification up to 20,000) and atomic force microscope (AFM, Park Systems, XE-100, non-contact, area profile comparison, 10 × 10 µm, 40 × 40 µm), the surface quality of the following diffractive IOLs was studied: the AcrySof IQ PanOptix (Alcon, USA), the AT LARA 829MP (Carl Zeiss Meditec, Germany), and Tecnis Symfony (Johnson&Johnson Vision, USA). The measurements were made over three representative areas (central non-diffractive optic, central diffractive optic, and diffractive step) of each IOL. Roughness profile in terms of mean arithmetic roughness (Ra) and root-mean-squared roughness (Rq) values were obtained and compared statistically. Results In SEM examination, all IOLs showed a smooth optical surface without any irregularities at low magnification. At higher magnification, Tecnis Symfony showed unique highly regular, concentric, and lineate structures in the diffractive optic area which could not be seen in the other studied diffractive IOLs. The differences in the measured Ra and Rq values of the Tecnis Symfony were statistically significant compared to the other models (p < 0.05). Conclusion Various different topographical traits were observed in three diffractive multifocal IOLs. The Ra values of all studied IOLs were within an acceptable range. Tecnis Symfony showed statistically significant higher surface Ra values at both central diffractive optic and diffractive step areas. Furthermore, compared to its counterparts, Tecnis Symfony demonstrated highly ordered, concentric pattern in its diffractive surfaces.

High-pressure far-infrared absorption measurements on La1−xCaxMnO3−δ by means of synchrotron radiation

2006 ◽  
Vol 49 (1-2) ◽  
pp. 92-95
Author(s):  
A. Sacchetti ◽  
M. Cestelli Guidi ◽  
E. Arcangeletti ◽  
P. Postorino ◽  
A. Nucara ◽  
...  
Keyword(s):  
High Pressure ◽  
Synchrotron Radiation ◽  
Infrared Absorption ◽  
Far Infrared ◽  
Absorption Measurements

scholarly journals Capacity-related interfacility patient transports: patients affected, wait times involved and associated morbidity

CJEM ◽  
2006 ◽  
Vol 8 (04) ◽  
pp. 262-268 ◽  
Author(s):  
Esther Stolte ◽  
Rod Iwanow ◽  
Christine Hall
Keyword(s):  
Transport Process ◽  
Transitional Care ◽  
Psychiatric Patients ◽  
Wait Time ◽  
The Other ◽  
Health Records ◽  
Lengths Of Stay ◽  
Patient Morbidity ◽  
Canadian City ◽  
Full Capacity

ABSTRACTObjectives:The trend toward operating Canadian hospitals at full capacity necessitates in some settings the transfer of patients from one hospital's emergency department (ED) to another hospital for admission, due to lack of bed availability at the first hospital. Our objectives were to determine how many and which patients are transported, to measure how much time is spent in the peri-transport process and to document any morbidity or mortality associated with these periods of transitional care.Methods:In this retrospective, observational health records review, we obtained health records during February, June and October 2002 for patients evaluated in any 1 of 3 adult EDs from a single Canadian city and subsequently transferred for admission to 1 of the other 2 hospitals. Data included the reason for transport, admitting service, transport process times and administration of key medications (asthma, cardiac, diabetes, analgesic or antibiotics).Results:Five hundred and thirteen records of transported patients were reviewed, and 507 were evaluated. Of those, 372 (73.4%) transfers were capacity-related and 135 (26.6%) were transferred for specialty services. Of the capacity transports, 219 (58.9%) were admissions for psychiatry and 123 (33.1%) for medicine. Median wait time at the first hospital was 6.7 hours, being longest for psychiatric patients. Thirty patients (8.1%) missed 1 or more doses of a key medication in the peri-transport process, and 8 (2.2%) missed 2 or more.Conclusions:Overcrowding of hospitals is a significant problem in many Canadian EDs, resulting in measurable increases in lengths of stay. Transfers arranged to other facilities for admission further prolong lengths of stay. Increased boarding times can result in missed medications, which may increase patient morbidity. Further study is needed to assess the need for capacity transfers and the possible risk to patients associated with periods of transitional care.

Cathodoluminescence of Quartz, Silica and Thin Amorphous SiO2 Layers

1999 ◽  
Vol 560 ◽  
Author(s):  
T. Barfels ◽  
H.-J. Fitting ◽  
A. von Czarnowski
Keyword(s):  
Infrared Absorption ◽  
Structural Models ◽  
Hole Center ◽  
Amorphous Sio2 ◽  
Luminescence Centers ◽  
Oxygen Hole ◽  
Absorption Measurements

ABSTRACTCathodoluminescence and its temperature-dose behaviour of different modifications of SiO2 are presented. The detected luminescence bands are attributed to three optical active luminescence centers: the twofold coordinated silicon center (=Si:), the non-bridging oxygen hole center (NBOHC) and the self-trapped exciton (STE). The experiments are correlated with infrared absorption measurements. Existing structural models are discussed with reference to our results.

REDUCTIVE CLEAVAGE WITH METAL IN LIQUID AMMONIA: I. THE SELECTIVE CLEAVAGE OF THE BENZYLTHIO C—S BOND VERSUS THE BENZYLIDENEDIOXY C—O BOND IN METHYL S-BENZYL-4,6-O-BENZYLIDENE-2-THIO-α-D-ALTROPYRANOSIDES; THE INFLUENCE OF THE COSOLVENT 1,2-DIMETHOXYETHANE ON THE COURSE OF THE REACTION

1966 ◽  
Vol 44 (5) ◽  
pp. 591-602 ◽  
Author(s):  
U. G. Nayak ◽  
R. K. Brown
Keyword(s):  
Infrared Absorption ◽  
Liquid Ammonia ◽  
Reductive Cleavage ◽  
The Other ◽  
Metallic Sodium ◽  
Absorption Bands ◽  
Strong Band ◽  
The One ◽  
Infrared Absorption Bands ◽  
Phenyl Moiety

The improved solubility of methyl S-benzyl-4,6-O-benzylidene-2-thio-α-D-altropyranoside (1) in liquid ammonia diluted with 1,2-dimethoxyethane has permitted the selective cleavage by metallic sodium or lithium of the C—S bond to give methyl 4,6-O-benzylidene-2-thio-α-D-altropyranoside in 70–75% yield. On the other hand, the slight solubility of I in liquid ammonia alone results only in the completely hydrogenolyzed material, methyl 2-thio-α-D-altropyranoside, along with unchanged I.Generally, in liquid ammonia alone, reductive cleavage is rapid (15–20 min) and the benzylidene and benzyl groups are converted largely into toluene accompanied by a small amount of bibenzyl. In liquid ammonia – 1,2-dimethoxyethane mixtures the reaction is much slower (≥ 1.5 h); under these conditions the benzylidene and benzyl groups are converted to a larger extent into bibenzyl, the rest becoming toluene.The two strong infrared absorption bands (in Nujol) in the region of 766 to 778 cm−1 and 706 to 718 cm−1 have been assigned to the phenyl moiety of the benzylidene group, and the one strong band in the region of 702 cm−1 to the phenyl moiety of the S-benzyl group.

Separation of Vitamins D2 and D3 as Isotachysterols D2 and D3 by Gas-Liquid Chromatography

1968 ◽  
Vol 51 (4) ◽  
pp. 834-838
Author(s):  
A J Sheppard ◽  
Denis E Lacroix ◽  
A R Prosser
Keyword(s):  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Infrared Absorption ◽  
Quantitative Measurement ◽  
Acetyl Chloride ◽  
Internal Standard ◽  
The Other ◽  
Gas Liquid Chromatography ◽  
Absorption Data

Abstract A method for the quantitative determination of 0.5—20 μg vitamins D2 and D3 by gas-liquid chromatography is described. Vitamins D2 and D3 are completely isomerized to their respective isotachysterol isomers by acetyl chloride as demonstrated by ultraviolet and infrared absorption data. Dihydrotachysterol D2, isotachysterol D2, and isotachysterol D3 are completely resolved with a 3% JXR on 100-120 mesh Gas Chrom Q column packing. Calibration studies show that each compound exhibited a characteristic dose-response plot. Therefore, one isomer cannot be used as a direct internal standard for the quantitative measurement of the other isomer.

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