scholarly journals Design and Synthesis of Bio-Inspired Polyurethane Films with High Performance

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2727
Author(s):  
Eva Marina Briz-López ◽  
Rodrigo Navarro ◽  
Héctor Martínez-Hernández ◽  
Lucía Téllez-Jurado ◽  
Ángel Marcos-Fernández
Keyword(s):  
High Performance ◽  
Soft Segment ◽  
Degree Of Polymerization ◽  
Synthetic Route ◽  
New Approach ◽  
Design And Synthesis ◽  
Molecular Adhesion ◽  
Secondary Reactions ◽  
Segmented Polyurethanes ◽  
Low Performance

In the present work, the synthesis of segmented polyurethanes functionalized with catechol moieties within the hard or the soft segment is presented. For this purpose, a synthetic route of a new catechol diol was designed. The direct insertion of this catechol-free derivative into the rigid phase led to segmented polyurethanes with low performance (σmax ≈ 4.5 MPa). Nevertheless, when the derivative was formally located within the soft segment, the mechanical properties of the corresponding functionalized polyurethane improved considerably (σmax ≈ 16.3 MPa), owing to a significant increase in the degree of polymerization. It is proposed that this difference in reactivity could probably be attributed to a hampering effect of this catecholic ring during the polyaddition reaction. To corroborate this hypothesis, a protection of the aromatic ring was carried out, blocking the hampering effect and avoiding secondary reactions. The polyurethane bearing the protected catechol showed the highest molecular weight and the highest stress at break described to date (σmax ≈ 66.1 MPa) for these kind of catechol-functionalized polyurethanes. Therefore, this new approach allows for the obtention of high-performance polyurethane films and can be applied in different sectors, benefiting from the molecular adhesion introduced by the catechol ring.

Theoretical Interpretation of High-Performance Chromatographic Data for a Heterogeneous Series of Compounds

1992 ◽  
Vol 57 (1) ◽  
pp. 33-45
Author(s):  
Vladimír Jakuš
Keyword(s):  
Experimental Data ◽  
High Performance ◽  
Theoretical Interpretation ◽  
Retention Data ◽  
Theoretical Evaluation ◽  
New Approach ◽  
Free Energy Of Solvation ◽  
Rp Hplc ◽  
Mobile Phases ◽  
Reversed Phases

A new approach to theoretical evaluation of the Gibbs free energy of solvation was applied for estimation of retention data in high-performance liquid chromatography on reversed phases (RP-HPLC). Simple and improved models of stationary and mobile phases in RP-HPLC were employed. Statistically significant correlations between the calculated and experimental data were obtained for a heterogeneous series of twelve compounds.

Vacuum processed large area doped thin-film crystals: A new approach for high-performance organic electronics

2021 ◽  
Vol 17 ◽  
pp. 100352
Author(s):  
S.-J. Wang ◽  
M. Sawatzki ◽  
H. Kleemann ◽  
I. Lashkov ◽  
D. Wolf ◽  
...  
Keyword(s):  
Thin Film ◽  
Organic Electronics ◽  
High Performance ◽  
Large Area ◽  
New Approach

scholarly journals Can artificially selected phenotypes influence a component of field fitness? Thermal selection and fly performance under thermal extremes

2006 ◽  
Vol 274 (1611) ◽  
pp. 771-778 ◽  
Author(s):  
Torsten Nygaard Kristensen ◽  
Volker Loeschcke ◽  
Ary A Hoffmann
Keyword(s):  
High Performance ◽  
Quantitative Traits ◽  
Genetic Basis ◽  
Selected Lines ◽  
Resistant Lines ◽  
Correlated Patterns ◽  
Different Temperatures ◽  
Evolutionary Trajectories ◽  
Low Performance ◽  
Selected Traits

Artificially selected lines are widely used to investigate the genetic basis of quantitative traits and make inferences about evolutionary trajectories. Yet, the relevance of selected traits to field fitness is rarely tested. Here, we assess the relevance of thermal stress resistance artificially selected in the laboratory to one component of field fitness by investigating the likelihood of adult Drosophila melanogaster reaching food bait under different temperatures. Lines resistant to heat reached the bait more often than controls under hot and cold conditions, but less often at intermediate temperatures, suggesting a fitness cost of increased heat resistance but not at temperature extremes. Cold-resistant lines were more common at baits than controls under cold as well as hot field conditions, and there was no cost at intermediate temperatures. One of the replicate heat-resistant lines was caught less often than the others under hot conditions. Direct and correlated patterns of responses in laboratory tests did not fully predict the low performance of the heat selected lines at intermediate temperatures, nor the high performance of the cold selected lines under hot conditions. Therefore, lines selected artificially not only behaved partly as expected based on laboratory assays but also evolved patterns only evident in the field releases.

ADDITIVE-VETO MODELS FOR CHOICE AND RANKING MULTICRITERIA DECISION PROBLEMS

2013 ◽  
Vol 30 (06) ◽  
pp. 1350026 ◽  
Author(s):  
ADIEL TEIXEIRA DE ALMEIDA
Keyword(s):  
High Performance ◽  
Additive Model ◽  
Additive Models ◽  
Numerical Application ◽  
Multicriteria Decision ◽  
Decision Methods ◽  
Overall Evaluation ◽  
Low Performance ◽  
Ranking Problems ◽  
Multicriteria Decision Problems

Using additive models for aggregation of criteria is an important procedure in many multicriteria decision methods. This compensatory approach, which scores the alternatives straightforwardly, may have significant drawbacks. For instance, the Decision Maker (DM) may prefer not to select alternatives which have a very low performance in whatever criterion. In contrast, such an alternative may have the best overall evaluation, since the additive model may compensate this low performance in one of the criteria as a result of high performance in other criteria. Thus, additive-veto models are proposed with a view to considering the possibility of vetoing alternatives in such situations, particularly for choice and ranking problems. A numerical application illustrates the use of such models, with a detailed discussion related to real practical problems. Moreover, the results obtained from a numerical simulation show that it is not so rare for a veto of the best alternative to occur in the additive model. This is of considerable relevance depending on the DM's preference structure.

Preparation and Characterization of Nanocellular Poly(phenylquinoxaline) Foams. A New Approach to Nanoporous High-Performance Polymers

2007 ◽  
Vol 40 (6) ◽  
pp. 2070-2078 ◽  
Author(s):  
Samuel Merlet ◽  
Catherine Marestin ◽  
Fréderic Schiets ◽  
Olivier Romeyer ◽  
Régis Mercier
Keyword(s):  
High Performance ◽  
New Approach ◽  
High Performance Polymers

scholarly journals Motivational system modulates brain responses during exploratory decision-making

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chia-Wei Li ◽  
Carol Yeh-Yun Lin ◽  
Ting-Ting Chang ◽  
Nai-Shing Yen ◽  
Danchi Tan
Keyword(s):  
Decision Making ◽  
High Performance ◽  
Behavioral Activation ◽  
Motivational Orientation ◽  
Performance Group ◽  
Reward Seeking ◽  
Brain Responses ◽  
Low Performance ◽  
Risk Choice ◽  
The Brain

AbstractManagers face risk in explorative decision-making and those who are better at such decisions can achieve future viability. To understand what makes a manager effective at explorative decision-making requires an analysis of the manager’s motivational characteristics. The behavioral activation/inhibition system (BAS/BIS), fitting the motivational orientation of “approach” or “avoidance,” can affect individual decision-making. However, very little is known about the neural correlates of BAS/BIS orientation and their interrelationship with the mental activity during explorative decision-making. We conducted an fMRI study on 111 potential managers to investigate how the brain responses of explorative decision-making interact with BAS/BIS. Participants were separated into high- and low-performance groups based on the median exploration-score. The low-performance group showed significantly higher BAS than that of the high-performance group, and its BAS had significant negative association with neural networks related to reward-seeking during explorative decision-making. Moreover, the BIS of the low-performance group was negatively correlated with the activation of cerebral regions responding to risk-choice during explorative decision-making. Our finding showed that BAS/BIS was associated with the brain activation during explorative decision-making only in the low-performance group. This study contributed to the understanding of the micro-foundations of strategically relevant decision-making and has an implication for management development.

Double-Sided Microchannel Cooling of a Power Electronics Module Using Power Overlay

2009 ◽  
Author(s):  
Adam G. Pautsch ◽  
Arun Gowda ◽  
Ljubisa Stevanovic ◽  
Rich Beaupre
Keyword(s):  
Power Electronics ◽  
High Performance ◽  
Mechanical Response ◽  
Thermal Contact ◽  
Small Scale ◽  
Micro Channel ◽  
Performance Technology ◽  
Actual Performance ◽  
Low Performance ◽  
Microchannel Cooling

In the continuing effort to alleviate the increasing thermal loads for power electronics devices, numerous aggressive solutions have been developed, such as small-scale micro-channel heat exchangers. Although these methods can improve overall surface heat transfer to the order of 500 W cm−2, they are limited to single-sided cooling due to the typical wire-bonded electrical connections of the devices. Power overlay (POL) technology provides a stable planar structure for electrical connection, as well as attachment of an additional top-side heat exchanger. This study presents an analysis of double-sided microchannel cooling of a power electronics module. Two optimized, integral micro-channel heat sinks were attached above and below silicon power devices, with more traditional attachment on one side and a POL interface on the other. A compliant TIM was selected for low thermal resistance and good mechanical response, which allowed top-side connection to the POL surface. A theoretical model is presented that predicts the benefit of double-sided cooling based on the known performance of a single-sided heat sink and given addition thermal contact resistance for the top side. For microchannels with water, an enhancement of 26% was predicted. An experiment was also carried out to measure the actual performance benefit seen with double-sided cooling. An enhancement of over 30% was measured for a particular design. As the theory predicts, the benefit of double-sided cooling is limited for high performance designs. However, double-sided cooling could lead to high levels of thermal performance using low-performance technology.

Sign in / Sign up

Export Citation Format

Share Document