scholarly journals Fiber Bragg Grating Wavelength Drift in Long-Term High Temperature Annealing

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1454
Author(s):  
Dan Grobnic ◽  
Cyril Hnatovsky ◽  
Sergey Dedyulin ◽  
Robert B. Walker ◽  
Huimin Ding ◽  
...  
Keyword(s):  
High Temperature ◽  
Fiber Bragg Gratings ◽  
Sensor Arrays ◽  
Physical Processes ◽  
Short Term ◽  
Bragg Wavelength ◽  
Distributed Sensor ◽  
Ambient Temperatures ◽  
High Temperature Processes

High-temperature-resistant fiber Bragg gratings (FBGs) are the main competitors to thermocouples as sensors in applications for high temperature environments defined as being in the 600–1200 °C temperature range. Due to their small size, capacity to be multiplexed into high density distributed sensor arrays and survivability in extreme ambient temperatures, they could provide the essential sensing support that is needed in high temperature processes. While capable of providing reliable sensing information in the short term, their long-term functionality is affected by the drift of the characteristic Bragg wavelength or resonance that is used to derive the temperature. A number of physical processes have been proposed as the cause of the high temperature wavelength drift but there is yet no credible description of this process. In this paper we review the literature related to the long-term wavelength drift of FBGs at high temperature and provide our recent results of more than 4000 h of high temperature testing in the 900–1000 °C range. We identify the major components of the high temperature wavelength drift and we propose mechanisms that could be causing them.

scholarly journals Nonmedical Interventions for Schizophrenia: A Review of Diet, Exercise and Social Roles

2020 ◽  
Author(s):  
Daniel S. Helman
Keyword(s):  
Term Treatment ◽  
Physical Processes ◽  
Dietary Interventions ◽  
Short Term ◽  
Alternative Interventions ◽  
Social Interventions ◽  
General Utility ◽  
Long Term Treatment ◽  
Abnormal Lipid Metabolism

Schizophrenia is a major mental illness with a disease course that is influenced by lifestyle. The risk-benefit ratio for alternative interventions is more favorable than for antipsychotics in long-term treatment. Dietary interventions may target autoimmune features, vitamin or mineral deficiencies, abnormal lipid metabolism, gluten sensitivity or others. Examples of interventions involving diet, physical activity or physical processes, or social interventions including talk therapy exist in the literature. Notwithstanding, the general utility of these types of interventions remains inconclusive, awaiting long-term randomized trials. A perspective that separates the cause of the disease from its symptoms may be helpful in treatment planning and is warranted to distinguish between short-term and long-term recovery goals.

scholarly journals High-temperature short-term and long hardness of sintered compact and porous titanium-siliceous carbide ti3sic2

2004 ◽  
Vol 36 (1) ◽  
pp. 11-20 ◽  
Author(s):  
S.A. Firstov ◽  
E.P. Pechkovsky
Keyword(s):  
High Temperature ◽  
Ternary Compound ◽  
Solid Phase ◽  
Porous Titanium ◽  
Critical Values ◽  
Holding Time ◽  
Short Term ◽  
Sintered Compact ◽  
Temperature Range

The ternary compound of titanium-siliceous carbide Ti3SiC2, one of the representatives of Nan laminates, prepared by solid-phase sintering is investigated in compact and porous (q=0.03-0.41) states. Features of its short-term and long-term hardness (?=10 N) behavior in the temperature range from 20 to 1200?? at a holding time of 1-60 min were studied. It is shown that a temperature of about 700?? and holding time under load of about 10 min are critical values of the indentation procedure that correspond to an intensive decrease of hardness. The presence of porosity results in a decrease in hardness. a deformation scheme of compact and porous titanium-siliceous carbide Ti3SiC2 in the temperature range from 20 to 1200?? is proposed. .

scholarly journals Effects of Different Ambient Temperatures on Caecal Microbial Composition in Broilers

2021 ◽  
Vol 70 (1) ◽  
Author(s):  
YUTING YANG ◽  
XING LI ◽  
ZHENHUI CAO ◽  
YINGING QIAO ◽  
QIUYE LIN ◽  
...  
Keyword(s):  
Temperature Stress ◽  
Short Term ◽  
Microbial Composition ◽  
Ambient Temperatures ◽  
Cellular Processes ◽  
Stress Biomarkers ◽  
Tnf Α ◽  
Shock Proteins ◽  
Environmental Information Processing

Short-term or acute temperature stress affect the immune responses and alters the gut microbiota of broilers, but the influences of long-term temperature stress on stress biomarkers and the intestinal microbiota remains largely unknown. Therefore, we examined the effect of three long-term ambient temperatures (high (HC), medium (MC), and low (LC) temperature groups) on the gene expression of broilers’ heat shock proteins (Hsps) and inflammation – related genes, as well as the caecal microbial composition. The results revealed that Hsp70 and Hsp90 levels in HC group significantly increased, and levels of Hsp70, Hsp90, IL-6, TNF-α, and NFKB1 in LC group were significantly higher than in MC group (p < 0.05). In comparison with the MC group, the proportion of Firmicutes increased in HC and LC groups, while that of Bacteroidetes decreased in LC group at phylum level (p < 0.05). At genus level, the proportion of Escherichia/Shigella, Phascolarctobacterium, Parabacteroides, and Enterococcus increased in HC group; the fraction of Faecalibacterium was higher in LC group; and the percentage of Barnesiella and Alistipes decreased in both HC and LC groups (p < 0.05). Functional analysis based on communities’ phylogenetic investigation revealed that the pathways involved in environmental information processing and metabolism were enriched in the HC group. Those involved in cellular processes and signaling, metabolism, and gene regulation were enriched in LC group. Hence, we conclude that the long-term temperature stress can greatly alter the intestinal microbial communities in broilers and may further affect the host’s immunity and health.

Performance Related Parameters of Flexible Connections Used in Offshore Pipelines

2002 ◽  
Author(s):  
Alok Kumar ◽  
Michael E. Hogan
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Mechanical Response ◽  
Structural Performance ◽  
Gas Mixture ◽  
Short Term ◽  
Offshore Pipelines ◽  
High Pressure High Temperature ◽  
Flexible Connections

Despite continued advances in rubber technology, the design of elastomeric flexible connections, used in offshore pipelines transporting high-pressure/high-temperature hydrocarbon fluid/gas mixture, remains more of an art than a science, primarily due to the intricate behavior of rubber. The mechanical response of rubber is dependent on time, temperature and mode of loading. It is susceptible to explosive decompression damage. Rubber’s non-linear stress-strain curves, creep, hysteresis and other properties are influenced not only by the method of fabrication but also by age. If these characteristics are not accounted for properly, the result can be less precision in design compared with metals. At present, there are no codes or standards that directly address the design, analysis or evaluation of the elastomeric flexible connections used in offshore oilfield applications. Based on the results of the recent research, the significance of key parameters that affect the short term and long term structural performance of elastomeric flexible connections is presented in this paper.

High-Temperature Properties of SiC-Si3N4 Particle Composites

1999 ◽  
Vol 122 (1) ◽  
pp. 8-12 ◽  
Author(s):  
G. Woetting ◽  
B. Caspers ◽  
E. Gugel ◽  
R. Westerheide
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Hot Pressing ◽  
Oxidation Behavior ◽  
Short Term ◽  
High Temperature Properties ◽  
Sintering Additive ◽  
Hot Pressing Sintering

Due to promising results in literature, SiC-Si3N4 particle composites in the range 0–100 percent SiC were evaluated. Focusing on high-temperature properties, mainly Y2O3 was used as sintering additive. Consolidation occurred primarily by hot-pressing, sintering tests were performed for comparison. Besides short-term properties like strength, toughness etc., long-term properties like creep and oxidation behavior were determined. Results as a function of SiC-content and microstructure were discussed with respect to materials’ performance at high temperatures and possibilities of their production on a technical scale. [S0742-4795(00)00201-5]

scholarly journals Linking long- and short-term emission variability in pulsars

2019 ◽  
Vol 488 (4) ◽  
pp. 5702-5712 ◽  
Author(s):  
P R Brook ◽  
A Karastergiou ◽  
S Johnston
Keyword(s):  
Time Scales ◽  
Radio Pulsars ◽  
Physical Processes ◽  
Short Term ◽  
Monitoring Technique ◽  
Wide Range ◽  
Statistical Detection ◽  
Short Time

ABSTRACT It is now known that the emission from radio pulsars can vary over a wide range of time-scales, from fractions of seconds to decades. However, it is not yet known if long- and short-term emission variability are caused by the same physical processes. It has been observed that long-term emission variability is often correlated with rotational changes in the pulsar. We do not yet know if the same is true of short-term emission variability, as the rotational changes involved cannot be directly measured over such short time-scales. To remedy this, we propose a continuous pulsar monitoring technique that permits the statistical detection of any rotational changes in nulling and mode-changing pulsars with certain properties. Using a simulation, we explore the range of pulsar properties over which such an experiment would be possible.

scholarly journals High-Temperature Properties of SiC-Si3N4 Particle Composites

1998 ◽  
Author(s):  
Gerhard Woetting ◽  
Bernhard Caspers ◽  
Ernst Gugel ◽  
Ralf Westerheide
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Hot Pressing ◽  
Oxidation Behavior ◽  
Short Term ◽  
High Temperature Properties ◽  
Sintering Additive ◽  
Hot Pressing Sintering

Due to promising results in literature, SiC-Si3N4 particle composites in the range 0–100% SiC were evaluated. Focusing on high-temperature properties, mainly Y2O3 was used as sintering additive. Consolidation occurred primarily by hot-pressing, sintering tests were performed for comparison. Besides short-term properties like strength, toughness etc., long-term properties like creep and oxidation behavior were determined. Results as a function of SiC-content and microstructure were discussed with respect to materials’ performance at high temperatures and possibilities of their production on a technical scale.

The Possible Interaction of Harderian Material and Saliva for Thermoregulation in the Mongolian Gerbil, Meriones Unguiculatus

1989 ◽  
Vol 68 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Mitzie Grant ◽  
Del Thiessen
Keyword(s):  
Ambient Temperature ◽  
Mongolian Gerbil ◽  
Evaporative Cooling ◽  
Meriones Unguiculatus ◽  
High Ambient Temperature ◽  
Short Term ◽  
Ambient Temperatures ◽  
Saliva Production ◽  
Thermoregulatory Reactions

Self-grooming in Meriones unguiculatus is associated with saliva spread and the release and spread of Harderian material from the external nares. Saliva spread results in evaporative cooling and Harderian spread insulates the pelage. Two experiments tested the predictions that (1) saliva production and Harderian material decrease systematically following a self-groom, (2) high ambient temperature (34°C) increases saliva production but decreases Harderian release, and (3) low ambient temperature (7°C) decreases saliva production but increases Harderian release. The predictions were generally confirmed, suggesting that short-term and long-term thermoregulatory reactions are differentially affected by ambient temperatures. Thus, an animal will tend to emphasize saliva production when evaporative cooling is needed and will exaggerate Harderian release when insulation of the pelage is required.

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