Fabrication of Boron Compensated Hydrogenated Amorphous Silicon Films with Significantly Improved Stability Using Plasma Enhanced Chemical Vapor Deposition Technique

1995 ◽  
Vol 377 ◽  
Author(s):  
Mohan K. Bhan
Keyword(s):  
Chemical Vapor ◽  
Short Term ◽  
Term Stability ◽  
Long Term Stability ◽  
Vapor Deposition Technique ◽  
Improved Stability ◽  
Donor Acceptor ◽  
B Doping ◽  
The Stability

ABSTRACTWe have systematically investigated the effects of addition of sub-ppm levels of boron on the stability of a-Si:H films and p-i-n devices, deposited by PE-CVD technique. The films thus produced with appropriate amounts of boron, show a significant improvement in stability, when soaked under both AM 1.5 (short-term) as well as 10×sun (long-term) illumination conditions. The opto-electronic properties of the films are quite respectable It is concluded that boron compensates the native impurities by forming donor-acceptor pairs, which reduces the “fast” defects and hence the initial degradation of the films. It is also speculated that boron may also be improving the short-term stability, by reducing the recombination of light generated electrons and holes, by converting D° into D+ states. The long-term stability appears to get affected by hydrogen dilution which seems to reduce the amount of “slow” defects. As a result of B doping of i-layer, the initial conversion efficiency of the devices decreases. It is presumed that our devices may contain an enhanced level of boron impurity, than expected, making them as worse material and to degrade less.

Investigation of Titanium in Metamict Nb-Ta-Ti Oxides Using the Extended X-Ray Absorption Fine Structure Technique

1981 ◽  
Vol 11 ◽  
Author(s):  
R. B. Greegor ◽  
F. W. Lytle ◽  
R. C. Ewing ◽  
R. F. Haaker
Keyword(s):  
Radiation Effects ◽  
Short Term ◽  
Term Stability ◽  
Long Term Stability ◽  
Ti Oxides ◽  
Considerable Controversy ◽  
Simple Phase ◽  
The Stability ◽  
X Ray Absorption

Recent proposals have suggested that radioactive wastes can be isolated 1 as dilute solid solutions in a crystalline, titanate assemblage. One titanate assemblage, SYNROC, consists of zirconolite (CaZrTi207), perovskite (CaTiO3) and "hollandite" (BaAl2Ti6016) with additional accessory phases. There are two major problems in the evaluation of the long term stability of any crystalline wasteform such as SYNROC: 1) it is difficult to assess the long term stability of materials from short term laboratory experiments that are not necessarily valid simulations of complex geochemical processes, and 2)the corresponding titanate minerals are uncommon, making it difficult to study long term alteration and radiation effects on a significant number of specimens from different localities and geologic environments. There has even been considerable controversy concerning the stability of the reasonably common and simple phase, perovskite (CaTiO3)

Remarks on the stability of temporary cuts

1990 ◽  
Vol 27 (5) ◽  
pp. 687-692 ◽  
Author(s):  
S. Leroueil ◽  
P. La Rochelle ◽  
F. Tavenas ◽  
M. Roy
Keyword(s):  
Undrained Shear Strength ◽  
Short Term ◽  
Overconsolidation Ratio ◽  
Term Stability ◽  
Long Term Stability ◽  
Liquidity Index ◽  
The Stability ◽  
Insight Into ◽  
Undrained Shear

A re-analysis of the observations and data related to the stability of excavations in clays gives a new insight into the problem. It is shown that for clays with a liquidity index greater than 0.4, the short-term stability can be estimated on the basis of the undrained shear strength without applying any correction factor; it is also shown that the long-term stability is lower than the short-term stability by an amount that depends on the overconsolidation ratio of the clay. Finally, experience proving that pore-pressure equilibration is highly variable and difficult to predict, it is recommended to systematically instrument excavations with piezometers. Key words: clay, short-term stability, long-term stability, excavations, pore pressures, overconsolidation ratio.

scholarly journals Stability of a thermophilic TIM-barrel enzyme: indole-3-glycerol phosphate synthase from the thermophilic archaeon Sulfolobus solfataricus*

1997 ◽  
Vol 323 (1) ◽  
pp. 259-264 ◽  
Author(s):  
Giuseppina ANDREOTTI ◽  
M. Vittoria CUBELLIS ◽  
Michela DI PALO ◽  
Dimitrios FESSAS ◽  
Giovanni SANNIA ◽  
...  
Keyword(s):  
Sulfolobus Solfataricus ◽  
Order Kinetic ◽  
Glycerol Phosphate ◽  
Short Term ◽  
Term Stability ◽  
Long Term Stability ◽  
Thermophilic Archaeon ◽  
The Stability ◽  
Phosphate Synthase

The stability and activity of indole-3-glycerol phosphate synthase from Sulfolobus solfataricus were studied as a function of pH and temperature. In this paper we focus on three points: (1) the long-term stability of the protein to irreversible denaturation at high temperature; (2) the short-term stability of the protein to reversible temperature-driven unfolding; and (3) the dependence of its activity on temperature. Results can be summarized as follows: (a) the same first-order kinetic constant (0.020±0.003 min-1) was determined at different pH values (6.5, 8.0 and 9.5) from long-term stability experiments at 80 °C; (b) short-term stability experiments revealed different behaviour in two different pH ranges (6.5-8.0, 8.5-9.5), suggesting that the melting temperature is higher at alkaline than at neutral pH; (c) the dependence of activity on temperature was investigated at pH 7.0 and 9.0, and a discontinuity was observed in the Arrhenius plot of kcat values at pH 9.0. We also investigated the stability in the presence of guanidinium chloride at 20 °C either at pH 7.0 or at pH 9.0, and we present data that indicate that the unfolding mechanism closely approaches a two-state model at pH 7.0 and a more complex mechanism at pH 9.0. Satisfactory fitting of the equilibrium unfolding transition obtained by fluorescence measurements at pH 9.0 required a model that involves a stable intermediate in addition to the native and unfolded forms. At 20 °C the folded conformation is more stable than the unfolded conformation by (14.7±1.2) kJ/mol at pH 7.0 and by (25.5±1.8) kJ/mol at pH 9.0.

scholarly journals A survey of short-term and long-term stability of tube parameters in a mammography unit

2014 ◽  
Vol 29 (4) ◽  
pp. 321-325
Author(s):  
Jovica Praskalo ◽  
Jasna Davidovic ◽  
Biljana Kocic ◽  
Monika Zivkovic ◽  
Svetlana Pejovic
Keyword(s):  
Screening Program ◽  
Short Term ◽  
X Ray ◽  
Term Stability ◽  
Long Term Stability ◽  
Mammography Screening Program ◽  
The Republic ◽  
Set Up ◽  
The Given

In order to set up a successful mammography screening program in the Republic of Srpska, a Siemens Mammomat 1000 X-ray machine was selected for analysis as the said mammography system is widely used in clinical practice. The variations in tube parameters (specific air kerma, high-voltage accuracy and reproducibility, linearity between exposure and dose exposure time) were monitored over a five-year period, from 2008 to 2012. In addition, due to observed daily fluctuations for chosen parameters, a series of measurements were performed three times a day within a single-month period (mainly October 2012). The goal of such an experimental set up is to assess short-term and long-term stability of tube parameters in the given mammography unit and to make a comparison between them. The present paper shows how an early detection of significant parameter fluctuations can help eliminate irregularities and optimize the performance of mammography systems.

scholarly journals Research on the solidification of silt with cement and zeolite as additives

2016 ◽  
Vol 1 (1) ◽  
pp. 35
Author(s):  
Feng Cheng ◽  
Wang Baotian ◽  
Li Shoude
Keyword(s):  
Heavy Metal ◽  
Industrial Pollution ◽  
Unconfined Compressive Strength ◽  
Effective Solution ◽  
Short Term ◽  
Time Saving ◽  
Term Stability ◽  
Long Term Stability ◽  
Environment Problem

Silt solidification is an important method of silt disposal,and it’s proved to be quick effectiveness and time saving and large in capacity.In recent years,the industrial pollution has made the silt in the lake or the sea rich in harmful elements,such as heavy metal and organic matter,etc,which may strongly influence the solidification effect of silt and trigger secondary pollution.The author proposed a kind of choice,which could effectly decrease harmful elements leaching,based on engineering application.The performances of solidification with different ratio of cement and zeolite,such as unconfined compressive strength,compression coefficient,heavy metal fractions,heavy metal short-term stability and long-term stability are systematicly studied.The article confirmed that the addition of the cement and the zeolite increase the strength of the soil and effectly enhance its deformation resistant capability,Further more,they significantly decrease the activity of harmful elements and greatly reduce the threat to the environment,which finds an effective solution to the environment problem.

LONG-TERM STABILITY ANALYSIS OF ACOUSTIC ABSORBING BOUNDARY CONDITIONS

2013 ◽  
Vol 23 (11) ◽  
pp. 2129-2154 ◽  
Author(s):  
HÉLÈNE BARUCQ ◽  
JULIEN DIAZ ◽  
VÉRONIQUE DUPRAT
Keyword(s):  
Stability Analysis ◽  
Boundary Conditions ◽  
Absorbing Boundary Conditions ◽  
Computational Domain ◽  
Acoustic Wave Equation ◽  
Absorbing Boundary ◽  
Term Stability ◽  
Long Term Stability ◽  
The Stability

This work deals with the stability analysis of a one-parameter family of Absorbing Boundary Conditions (ABC) that have been derived for the acoustic wave equation. We tackle the problem of long-term stability of the wave field both at the continuous and the numerical levels. We first define a function of energy and show that it is decreasing in time. Its discrete form is also decreasing under a Courant–Friedrichs–Lewy (CFL) condition that does not depend on the ABC. Moreover, the decay rate of the continuous energy can be determined: it is exponential if the computational domain is star-shaped and this property can be illustrated numerically.

scholarly journals Rational design of MgF2 catalysts with long-term stability for the dehydrofluorination of 1,1-difluoroethane (HFC-152a)

RSC Advances ◽  
2019 ◽  
Vol 9 (41) ◽  
pp. 23744-23751 ◽  
Author(s):  
Haodong Tang ◽  
Mingming Dang ◽  
Yuzhen Li ◽  
Lichun Li ◽  
Wenfeng Han ◽  
...  
Keyword(s):  
Rational Design ◽  
Sol Gel ◽  
Hard Template ◽  
Term Stability ◽  
Long Term Stability ◽  
Improved Stability ◽  
Hfc 152A ◽  
Template Methods

In this study, sol–gel, precipitation and hard-template methods were applied to synthesize MgF2 catalysts with improved stability towards dehydrofluorination of hydrofluorocarbons and MgF2-T catalysts demonstrated superior long-term stability.

scholarly journals Weather fluctuations drive short‐term dynamics and long‐term stability in plant communities: A 25‐year study in a Central European dry grassland

2020 ◽  
Vol 31 (5) ◽  
pp. 711-721 ◽  
Author(s):  
Felícia M. Fischer ◽  
Kryštof Chytrý ◽  
Jakub Těšitel ◽  
Jiří Danihelka ◽  
Milan Chytrý
Keyword(s):  
Plant Communities ◽  
Short Term ◽  
Dry Grassland ◽  
Central European ◽  
Term Stability ◽  
Long Term Stability
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