The stability characterization of the pyrotechnic system. The degradation of the nitrate oxidant in the presence of the magnesium under the accelerated aging conditions

1992 ◽  
Vol 17 (1) ◽  
pp. 10-13 ◽  
Author(s):  
Ines Batinic-Haberle ◽  
Dubravka Barisin ◽  
Ivan Spasojevic ◽  
Zoran Vranic
Keyword(s):  
Accelerated Aging ◽  
Aging Conditions ◽  
Pyrotechnic System ◽  
The Stability

scholarly journals Effect of Sunlight, Moisture, Temperature and Ultraviolet Radiation on the Quality Control Parameters of Ciprofloxacin Tablet Formulation

2016 ◽  
Vol 8 (3) ◽  
pp. 99 ◽  
Author(s):  
Kenneth Ezealisiji ◽  
Angenlina Pepple ◽  
Catherine Stanley
Keyword(s):  
Relative Humidity ◽  
Uv Light ◽  
Physical Stability ◽  
Accelerated Aging ◽  
Storage Conditions ◽  
Dissolution Behavior ◽  
Ciprofloxacin Hydrochloride ◽  
Label Claim ◽  
Aging Conditions ◽  
The Stability

<p>This work assesses the stability and quality of Ciprofloxacin hydrochloride tablets after subjection to accelerated stability conditions of sunlight, temperature of 40±1<sup>0</sup>C, 75% relative humidity, and UV light of 365 nm for 4 hours each day. This study was performed at time zero and at 4-day intervals for a period of 45 days (that is, days 0, 4, 8, 12…40, 44) according to the International Conference on Harmonization (ICH) accelerated aging conditions and the results obtained were subjected to statistical analysis. The results showed that with increasing time there was a gradual reduction in the dissolution rate with the tablets exposed to all four storage conditions failing the test on day 44 where they had less than 80 % release of the label claim. For content of Ciprofloxacin Hydrochloride, only those tablets exposed to UV light passed the test for all 44 days as they had a minimum of 96.83 % content on the 44<sup>th</sup> day. At day 0, all the tablets assayed passed this test, having a ciprofloxacin content of 99.43 %. For those tablets subjected to the other storage conditions including temperature of 40±1<sup>0</sup>C, 75 % relative humidity and sunlight, they had ciprofloxacin content of 70.22 %, 71.50 %, and 78.36 % respectively. The results further, indicated that the storage conditions used in the study had a greater impact on the dissolution behavior and content of the Ciprofloxacin tablets than they did on the physical stability (hardness, uniformity of weight, disintegration).</p>

Ultrasonic Characterization of Degradation of Aging Epoxy Coating

2004 ◽  
Vol 449-452 ◽  
pp. 1209-1212 ◽  
Author(s):  
Noh Yu Kim ◽  
Hwan Seon Nah
Keyword(s):  
Reflection Coefficient ◽  
Acoustic Impedance ◽  
Accelerated Aging ◽  
Ultrasonic Measurement ◽  
Epoxy Coating ◽  
Acoustic Lens ◽  
Ultrasonic Characterization ◽  
Aging Conditions

Acoustic impedance of aging epoxy coating in nuclear plant is measured for evaluation of the degradation of the epoxy coating using a new ultrasonic measurement technique that uses a specially designed conical acoustic lens to determine the reflection coefficient (reflectance) of the epoxy coating. Reflection waves measured at two different vertical positions slightly apart from each other are subtracted and used to calculate the acoustic impedance of the epoxy coating. Epoxy coated concrete specimens are fabricated and degraded artificially under accelerated aging conditions to determine the acoustic impedance of the films. Experimental results show that the acoustic impedance is very sensitive to the degradation of coating and can be applied to evaluate the quality of the epoxy coating quantitatively.

Accelerated aging and characterization of HDPE pin type insulators (15 kV)

2021 ◽  
pp. 096739112110476
Author(s):  
Cynthia DC Erbetta ◽  
Maria Elisa SR Silva ◽  
Roberto FS Freitas ◽  
Ricardo G Sousa
Keyword(s):  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
High Density Polyethylene ◽  
Accelerated Aging ◽  
Natural Aging ◽  
Accelerated Weathering ◽  
Electrical System ◽  
Scanning Calorimetry ◽  
Aging Conditions

The study of the behavior of polymeric material used for insulators in the electrical system is extremely important in order to evaluate their lifetime as well as their performance when exposed to different environmental conditions. In the present work, the behavior of high-density polyethylene (HDPE) pin type insulators (15 kV), under accelerated aging conditions, was studied. Samples were exposed to aging, for 200 h, 1000 h, and 2000 h, in accelerated weathering chambers, according to two different methods. In Method 1, the parameters were established based on natural aging in location conditions, and in Method 2, ASTM G155 standard parameters were used. All samples were characterized by rheometry, Fourier-transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). The accelerated aging conditions, used in Methods 1 and 2, affected the aging of HDPE pin type insulators samples differently, the changes being more intense in Method 1.

scholarly journals Characterization of N-glycosylated type I collagen in streptozotocin-induced diabetes

1981 ◽  
Vol 197 (2) ◽  
pp. 405-412 ◽  
Author(s):  
A Le Pape ◽  
J P Muh ◽  
A J Bailey
Keyword(s):  
Type I Collagen ◽  
Accelerated Aging ◽  
Diabetic Rats ◽  
Type I ◽  
Significant Extent ◽  
Streptozotocin Induced Diabetes ◽  
Cross Links ◽  
The Stability

The N epsilon-glycosylation of lysine and hydroxylysine residues in collagen from streptozotocin-induced-diabetic rats was confirmed and the stability of the complex shown to be due to an Amadori rearrangement. The studies also demonstrate the relative specificities of glucose, galactose and mannose in their reaction with collagen. The glycosylation of lysine in vitro occurs with glucose and galactose, but not with mannose, whereas only gucose reacts with hydroxylysine to any significant extent. Glycosylation of collagen occurs slowly during normal aging, but in contrast with reports suggesting accelerated aging of collagen in diabetic animals, we clearly demonstrated that the apparent increased stability is not due to an acceleration of the normal maturation process involving the reducible cross-links.

TEM characterization of Au/Polysilicon interactions

1990 ◽  
Vol 48 (4) ◽  
pp. 650-651
Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer
Keyword(s):  
Solid Phase ◽  
Single Crystal Silicon ◽  
Chemical Vapor ◽  
Electrical Contacts ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Transmission Electron ◽  
Polysilicon Films ◽  
The Stability

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.

ACCELERATED AGING AND CHARACTERIZATION OF A PLASTICIZED POLY(ESTER URETHANE) BINDER

2007 ◽  
Author(s):  
DEBRA A. WROBLESKI ◽  
DAVID A. LANGLOIS ◽  
E. BRUCE ORLER ◽  
ANDREA LABOURIAU ◽  
MARIANA M. URIBE ◽  
...  
Keyword(s):  
Accelerated Aging

Preparation and Characterization of β-glucosidase Films for Stabilization and Handling in Dry Configurations

2020 ◽  
Vol 21 (8) ◽  
pp. 741-747
Author(s):  
Liguang Zhang ◽  
Yanan Shen ◽  
Wenjing Lu ◽  
Lengqiu Guo ◽  
Min Xiang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Protein Function ◽  
Protein Stabilization ◽  
Functional Protein ◽  
Elongation At Break ◽  
Gelatin Films ◽  
The Stability ◽  
And Function ◽  
General Method

Background: Although the stability of proteins is of significance to maintain protein function for therapeutical applications, this remains a challenge. Herein, a general method of preserving protein stability and function was developed using gelatin films. Method: Enzymes immobilized onto films composed of gelatin and Ethylene Glycol (EG) were developed to study their ability to stabilize proteins. As a model functional protein, β-glucosidase was selected. The tensile properties, microstructure, and crystallization behavior of the gelatin films were assessed. Result: Our results indicated that film configurations can preserve the activity of β-glucosidase under rigorous conditions (75% relative humidity and 37°C for 47 days). In both control films and films containing 1.8 % β-glucosidase, tensile strength increased with increased EG content, whilst the elongation at break increased initially, then decreased over time. The presence of β-glucosidase had a negligible influence on tensile strength and elongation at break. Scanning electron-microscopy (SEM) revealed that with increasing EG content or decreasing enzyme concentrations, a denser microstructure was observed. Conclusion: In conclusion, the dry film is a promising candidate to maintain protein stabilization and handling. The configuration is convenient and cheap, and thus applicable to protein storage and transportation processes in the future.

scholarly journals Investigation of Hydrothermally Stressed Silicone Rubber/Silica Micro and Nanocomposite for the Coating High Voltage Insulation Applications

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3567
Author(s):  
Faiza Faiza ◽  
Abraiz Khattak ◽  
Safi Ullah Butt ◽  
Kashif Imran ◽  
Abasin Ulasyar ◽  
...  
Keyword(s):  
Silicone Rubber ◽  
Structural Changes ◽  
Polymer Chains ◽  
Hydrothermal Conditions ◽  
Silica Filler ◽  
Before And After ◽  
Aging Conditions ◽  
The Stability ◽  
Micro Silica ◽  
Applied Stresses

Silicone rubber is a promising insulating material that has been performing well for different insulating and dielectric applications. However, in outdoor applications, environmental stresses cause structural and surface degradations that diminish its insulating properties. This effect of degradation can be reduced with the addition of a suitable filler to the polymer chains. For the investigation of structural changes and hydrophobicity four different systems were fabricated, including neat silicone rubber, a micro composite (with 15% micro-silica filler), and nanocomposites (with 2.5% and 5% nanosilica filler) by subjecting them to various hydrothermal conditions. In general, remarkable results were obtained by the addition of fillers. However, nanocomposites showed the best resistance against the applied stresses. In comparison to neat silicone rubber, the stability of the structure and hydrophobic behavior was better for micro-silica, which was further enhanced in the case of nanocomposites. The inclusion of 5% nanosilica showed the best results before and after applying aging conditions.

Field temperature and moisture loads from a building envelope as the basis for accelerated aging of barrier membranes

2019 ◽  
Vol 46 (11) ◽  
pp. 969-978 ◽  
Author(s):  
Marzieh Riahinezhad ◽  
Augusta Eve ◽  
Marianne Armstrong ◽  
Peter Collins ◽  
J.-F. Masson
Keyword(s):  
Building Materials ◽  
National Research Council ◽  
Accelerated Aging ◽  
Bimodal Distribution ◽  
Building Envelope ◽  
Rate Of Change ◽  
Single Family ◽  
Field Exposure ◽  
Aging Conditions ◽  
Materials Used

Temperature and relative humidity (RH) data within the building envelope of a single-family home at the National Research Council of Canada’s Canadian Centre for Housing Technology were collected over five years. We report on the distribution, rate of change, and the limits of temperature and moisture variations for south-easting wall and south-facing wall and roof systems to better understand the in-situ environmental conditions to which building materials and components typical of homes in North America may be subjected. Over an average year, wall temperature varied from −25 °C to +45 °C, and temperature followed a bimodal distribution, with maxima at 0 °C to 5 °C and 15 °C to 20 °C. Each maximum represented about 1100 h of field exposure. Roof temperatures, which spanned a temperature range from −35 °C to 75 °C, did not show a Gaussian distribution but were characterized as being multi-modal. From values of temperature and RH, absolute moisture contents within the building envelope were found to range between 1 and 55 g/m3, with the most common values being 6–8 g/m3. The application of this information is discussed and related to the development of realistic accelerated aging conditions to obtain a more accurate durability assessment of building envelope materials used in Canadian dwellings.

Effect of pH and temperature on the infectivity of human coronavirus 229E

1989 ◽  
Vol 35 (10) ◽  
pp. 972-974 ◽  
Author(s):  
Alain Lamarre ◽  
Pierre J. Talbot
Keyword(s):  
Incubation Period ◽  
Storage Conditions ◽  
Viral Infectivity ◽  
Human Coronavirus ◽  
Virus Growth ◽  
The Stability ◽  
And Storage ◽  
Influence Of Ph ◽  
Human Coronavirus 229E

The stability of human coronavirus 229E infectivity was maximum at pH 6.0 when incubated at either 4 or 33 °C. However, the influence of pH was more pronounced at 33 °C. Viral infectivity was completely lost after a 14-day incubation period at 22, 33, or 37 °C but remained relatively constant at 4 °C for the same length of time. Finally, the infectious titer did not show any significant reduction when subjected to 25 cycles of thawing and freezing. These studies will contribute to optimize virus growth and storage conditions, which will facilitate the molecular characterization of this important pathogen.Key words: coronavirus, pH, temperature, infectivity, human coronavirus.

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