Highly-Sensitive Humidity Sensors for Condition Monitoring of Hybrid Laminates

2015 ◽  
Vol 825-826 ◽  
pp. 579-585 ◽  
Author(s):  
Thomas Seider ◽  
Joerg Martin ◽  
Alexander Boeddicker ◽  
Julia Rühling ◽  
Daniel Wett ◽  
...  
Keyword(s):  
Condition Monitoring ◽  
Fold Increase ◽  
Humidity Sensors ◽  
Reinforced Polymers ◽  
Lightweight Structures ◽  
Humidity Change ◽  
Highly Sensitive ◽  
Hybrid Laminates ◽  
Low Mass ◽  
Response To Water

In recent years fibre-reinforced polymers (FRPs) gained importance in a wider field of application due to such favourable properties as low mass and tailorable mechanical strength. However, water penetrating into the lightweight material can lead to a loss of shear strength and finally to a collapse of the whole mechanical structure. Consequently, the integration of humidity sensors into compound materials is able to promote the reliability via online condition monitoring. An innovative concept is the use of ceramics-polymer-composites, which are well suited for the integration into lightweight structures during inline production. Composite and polyimide based humidity sensors have been manufactured by flexographic printing and spin-coating processes. A 5-fold increase in sensor’s capacity related to a humidity change from 10 to 80 % r.h. manifests the outstanding sensitivity of manufactured composite sensors. In addition, FRP-integrated polyimide sensors showed a significant response to water penetration, whereby the capability of condition monitoring could be confirmed.

scholarly journals Material-integrated composite humidity sensors for condition monitoring of fiber-reinforced plastics

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Jörg Martin ◽  
Kuldeep Shetty ◽  
Nadine Reimann ◽  
Stephan Neukirchner ◽  
Uta Fügmann ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Condition Monitoring ◽  
Continuous Monitoring ◽  
Fiber Reinforced ◽  
Humidity Sensors ◽  
Reinforced Plastics ◽  
Glass Fiber Reinforced ◽  
Highly Sensitive ◽  
Fiber Reinforced Plastics

Penetrating water in fiber-reinforced plastics can alter the mechanical properties considerably. To avoid potential resulting failure of the component, we propose continuous monitoring of the humidity inside the material by highly-sensitive humidity sensors based on nano- or microcomposites. Here we report on the inline-capable fabrication and integration of humidity sensors in glass fiber-reinforced polyamide (GF-PA6). Mean water concentrations of less than 0.5 wt. % have been clearly determined inside the laminate.   

Intrinsic Hybrid Composites for Lightweight Structures: New Process Chain Approaches

2016 ◽  
Vol 1140 ◽  
pp. 239-246 ◽  
Author(s):  
Simon Frederik Koch ◽  
Daniel Barfuss ◽  
Mathias Bobbert ◽  
Lukas Groß ◽  
Raik Grützner ◽  
...  
Keyword(s):  
Hybrid Composites ◽  
Process Chain ◽  
Lightweight Structures ◽  
Fiber Placement ◽  
Reinforced Plastics ◽  
Steel Sheets ◽  
Process Chains ◽  
New Process ◽  
Hybrid Laminates ◽  
Automated Fiber Placement

This publication describes new process chain approaches for the manufacturing of intrinsic hybrid composites for lightweight structures. The introduced process chains show a variety of different part and sample types, like insert technology for fastening of hollow hybrid shafts and profiles. Another field of research are hybrid laminates with different layers of carbon fiber reinforced plastics stacked with aluminum or steel sheets. The derived process chains base on automated fiber placement, resin transfer molding, deep drawing, rotational molding and integral tube blow molding.

scholarly journals Extreme bradycardia and tachycardia in the world’s largest animal

2019 ◽  
Vol 116 (50) ◽  
pp. 25329-25332 ◽  
Author(s):  
J. A. Goldbogen ◽  
D. E. Cade ◽  
J. Calambokidis ◽  
M. F. Czapanskiy ◽  
J. Fahlbusch ◽  
...  
Keyword(s):  
Heart Rate ◽  
Large Diameter ◽  
Large Body ◽  
Fold Increase ◽  
Oxygen Depletion ◽  
Blue Whale ◽  
Heart Rates ◽  
Physiological Limits ◽  
Low Mass ◽  
Lunge Feeding

The biology of the blue whale has long fascinated physiologists because of the animal’s extreme size. Despite high energetic demands from a large body, low mass-specific metabolic rates are likely powered by low heart rates. Diving bradycardia should slow blood oxygen depletion and enhance dive time available for foraging at depth. However, blue whales exhibit a high-cost feeding mechanism, lunge feeding, whereby large volumes of prey-laden water are intermittently engulfed and filtered during dives. This paradox of such a large, slowly beating heart and the high cost of lunge feeding represents a unique test of our understanding of cardiac function, hemodynamics, and physiological limits to body size. Here, we used an electrocardiogram (ECG)-depth recorder tag to measure blue whale heart rates during foraging dives as deep as 184 m and as long as 16.5 min. Heart rates during dives were typically 4 to 8 beats min−1 (bpm) and as low as 2 bpm, while after-dive surface heart rates were 25 to 37 bpm, near the estimated maximum heart rate possible. Despite extreme bradycardia, we recorded a 2.5-fold increase above diving heart rate minima during the powered ascent phase of feeding lunges followed by a gradual decrease of heart rate during the prolonged glide as engulfed water is filtered. These heart rate dynamics explain the unique hemodynamic design in rorqual whales consisting of a large-diameter, highly compliant, elastic aortic arch that allows the aorta to accommodate blood ejected by the heart and maintain blood flow during the long and variable pauses between heartbeats.

scholarly journals In-Situ Exploration of Dust in the Solar System and Initial Results from the Galileo Dust Detector

1991 ◽  
Vol 126 ◽  
pp. 21-28
Author(s):  
E. Grün ◽  
H. Fechtig ◽  
M. S. Hanner ◽  
J. Kissel ◽  
B.-A. Lindblad ◽  
...  
Keyword(s):  
Solar System ◽  
Impact Ionization ◽  
Interplanetary Space ◽  
Interplanetary Dust ◽  
High Mass ◽  
Large Area ◽  
Dust Flux ◽  
Highly Sensitive ◽  
Low Mass

AbstractIn-situ measurements of interplanetary dust have been performed in the heliocentric distance range from 0.3 AU out to 18 AU. Due to their small sensitive areas (typically 0.01 m2for the highly sensitive impact ionization sensors) or low mass sensitivities (≥10−9g of the large area penetration detectors) previous instruments recorded only a few 100 impacts during their lifetimes. Nevertheless, important information on the distribution of dust in interplanetary space has been obtained between 0.3 and 18 AU distance from the Sun. The Galileo dust detector combines the high mass sensitivity of impact ionization detectors (10−15g) together with a large sensitive area (0.1 m2). The Galileo spacecraft was launched on October 18, 1989 and is on its solar system cruise towards Jupiter. Initial measurements of the dust flux from 0.7 to 1.2 AU are presented.

scholarly journals Detection of Nine M8.0–L0.5 Binaries: The Very Low Mass Binary Population and Its Implications for Brown Dwarf Formation Theories

2003 ◽  
Vol 211 ◽  
pp. 249-256
Author(s):  
Laird M. Close ◽  
Nick Siegler ◽  
Melanie Freed
Keyword(s):  
Wave Front ◽  
Adaptive Optics ◽  
Major Axis ◽  
Broad Peak ◽  
Brown Dwarf ◽  
Semi Major Axis ◽  
Highly Sensitive ◽  
Low Mass ◽  
First Time

Use of the highly sensitive Hōkūpa'a/Gemini curvature wave-front sensor has allowed for the first time direct adaptive optics (AO) guiding on very low mass (VLM) stars with SpT=M8.0–L0.5. A survey of 39 such objects detected 9 VLM binaries (7 of which were discovered for the first time to be binaries). Most of these systems (55%) are tight (separation < 5 AU) and have similar masses (ΔKs < 0.8 mag; 0.85 < q < 1.0). However, 2 systems (LHS 2397a, and 2M2331016-040618) have large ΔKs > 2.38 mag and consist of a VLM star orbited by a much cooler L6.5–L8.5 brown dwarf companion. Based on our initial flux limited (Ks < 12 mag) survey of 39 M8.0–L0.5 stars (mainly from the sample of Gizis et al. 2000) we find a binary fraction in the range 19±7% for M8.0–L0.5 binaries with separations > 2.6 AU. This is slightly less than the 32 ± 9% measured for more massive (M0–M4) stars over the same separation range (Fischer & Marcy 1992). It appears M8.0–L0.5 binaries (as well as L and T dwarf binaries) have a much smaller semi-major axis distribution peak (~ 4 AU) compared to more massive M and G stars which have a broad peak at larger ~ 30 AU separations. We also find no VLM binaries (Mtot < 0.18M⊙) with separations > 20 AU. We find that a velocity “kick” of ~ 3 km/s can reproduce the observed cut-off in the semi-major axis distribution at ˜ 20 AU. This kick may have been from the VLM system being ejected from its formation mini-cluster.

scholarly journals Ultrafast and Highly Sensitive Chemically Functionalized Graphene Oxide-Based Humidity Sensors: Harnessing Device Performances via the Supramolecular Approach

2020 ◽  
Vol 12 (39) ◽  
pp. 44017-44025
Author(s):  
Cosimo Anichini ◽  
Alessandro Aliprandi ◽  
Sai Manoj Gali ◽  
Fabiola Liscio ◽  
Vittorio Morandi ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Functionalized Graphene ◽  
Humidity Sensors ◽  
Functionalized Graphene Oxide ◽  
Highly Sensitive

Highly sensitive humidity sensors based on Sb-doped ZnSnO3 nanoparticles with very small sizes

CrystEngComm ◽  
2014 ◽  
Vol 16 (14) ◽  
pp. 2977 ◽  
Author(s):  
Jidong Li ◽  
Tao Fu ◽  
Yuejiao Chen ◽  
Bingkun Guan ◽  
Ming Zhuo ◽  
...  
Keyword(s):  
Humidity Sensors ◽  
Highly Sensitive

Oxytocin as an antidiuretic hormone. I. Concentration dependence of action

1995 ◽  
Vol 269 (1) ◽  
pp. F70-F77 ◽  
Author(s):  
C. L. Chou ◽  
S. R. DiGiovanni ◽  
R. Mejia ◽  
S. Nielsen ◽  
M. A. Knepper
Keyword(s):  
Antidiuretic Hormone ◽  
Water Permeability ◽  
Water Channel ◽  
Fold Increase ◽  
Brattleboro Rats ◽  
Sprague Dawley ◽  
Water Restriction ◽  
Sprague Dawley Rats ◽  
Osmotic Water ◽  
Response To Water

Circulating concentrations of oxytocin increase to 10-40 pM in rats in response to osmotic stimuli, suggesting that oxytocin could play a role in regulation of water balance. The present studies tested whether oxytocin at such concentrations increases osmotic water permeability (Pf) in isolated perfused terminal inner medullary collecting ducts (IMCD). In IMCD segments from Sprague-Dawley rats, 20 pM oxytocin added to the peritubular bath caused a two- to threefold increase in Pf, whereas 200 pM oxytocin increased Pf by five- to sixfold (n = 8, P < 0.01). IMCD from Brattleboro rats, which manifest central diabetes insipidus, exhibited a 2.8-fold increase in Pf in response to 20 pM oxytocin and a 4.7-fold increase in response to 200 pM oxytocin. However, in Brattleboro rats, the response to 20 pM oxytocin was dependent on prior water restriction of the rats. Immunoblotting showed no change in the expression of the aquaporin-CD water channel in Brattleboro rats in response to water restriction. Nevertheless, immunofluorescence studies of inner medullary tissue from Brattleboro rats revealed a marked redistribution of the aquaporin-CD water channels to a predominantly apical and subapical localization in IMCD cells in response to water restriction, similar to the redistribution seen in response to vasopressin. Mathematical modeling studies revealed that the measured increase in Pf in response to oxytocin is sufficient to generate a concentrated urine. We conclude that oxytocin can function physiologically as an antidiuretic hormone, mimicking the short-term action of vasopressin on water permeability, albeit with somewhat lower potency.

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