scholarly journals Butterfly wing architectures inspire sensor and energy applications

2020 ◽  
Author(s):  
Maurice I Osotsi ◽  
Wang Zhang ◽  
Imran Zada ◽  
Jiajun Gu ◽  
Qinglei Liu ◽  
...  
Keyword(s):  
Environmental Remediation ◽  
Light Trapping ◽  
Functional Materials ◽  
Butterfly Wing ◽  
Energy Materials ◽  
Energy Applications ◽  
Wing Scale ◽  
Improved Performance ◽  
And Performance ◽  
External Stimuli

Abstract Natural biological systems are constantly developing efficient mechanisms to counter adverse effects of increasing human population and depleting energy resources. Their intelligent mechanisms are characterized by the ability to detect changes in the environment, store and evaluate information, and respond to external stimuli. Bio-inspired replication into man-made functional materials guarantees enhancement of characteristics and performance. Specifically, butterfly architectures have inspired the fabrication of sensor and energy materials by replicating their unique micro/nanostructures, light-trapping mechanisms and selective responses to external stimuli. These bio-inspired sensor and energy materials have shown improved performance in harnessing renewable energy, environmental remediation and health monitoring. Therefore, this review highlights recent progress reported on the classification of butterfly wing scale architectures and explores several bio-inspired sensor and energy applications.

A Photo-Curing Method to Prepare Biomimetic Micro-Nano Structure of Butterfly Wing Scale

2015 ◽  
Vol 713-715 ◽  
pp. 2576-2580
Author(s):  
Wei Wang ◽  
Gang Wang ◽  
Ping She ◽  
Hang Sun ◽  
Zhen Ning Liu
Keyword(s):  
Large Scale ◽  
Light Trapping ◽  
Dendritic Structure ◽  
Utilization Rate ◽  
Butterfly Wing ◽  
Multiple Reflections ◽  
Nano Structure ◽  
Illumination Time ◽  
Wing Scale ◽  
Photo Curing

It has been well-known that butterfly wings possess interesting optic properties. Recently, dendritic micro-nanostructure has been found in the wing scales of butterfly Trogonoptera brookiana, which shows excellent light-trapping effect, especially for the visible light. When light enters such a dendritic micro-nanostructure, it will be trapped and eventually absorbed by multiple reflections to generate heat. It is desirable to prepare a biomimetic structure resembling the micro-nanostructure of the butterfly wing scale, which may lead to a new material that can potentially improve the light utilization rate of solar thermal heater and other similar applications. However, a convenient method to make such a structure in large scale is still lacking. Herein, an easy and handy approach has been developed to prepare biomimetic dendritic structure. The starting material is negative photoresist, a chemical reagent which is widely used in photography. A simple device that can adjust the intensity and interval of ultraviolet illumination has been designed and set up. A periodic structure has been achieved via photo-curing with ultraviolet light and the ratio of illumination time has been optimized.

scholarly journals Advanced Functional Materials for Intelligent Thermoregulation in Personal Protective Equipment

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3711
Author(s):  
Alireza Saidi ◽  
Chantal Gauvin ◽  
Safa Ladhari ◽  
Phuong Nguyen-Tri
Keyword(s):  
Personal Protective Equipment ◽  
Functional Materials ◽  
Polymeric Materials ◽  
Protective Equipment ◽  
Sensors And Actuators ◽  
Physical Hazards ◽  
Current State ◽  
Smart Textile ◽  
Improved Performance ◽  
External Stimuli

The exposure to extreme temperatures in workplaces involves physical hazards for workers. A poorly acclimated worker may have lower performance and vigilance and therefore may be more exposed to accidents and injuries. Due to the incompatibility of the existing standards implemented in some workplaces and the lack of thermoregulation in many types of protective equipment that are commonly fabricated using various types of polymeric materials, thermal stress remains one of the most frequent physical hazards in many work sectors. However, many of these problems can be overcome with the use of smart textile technologies that enable intelligent thermoregulation in personal protective equipment. Being based on conductive and functional polymeric materials, smart textiles can detect many external stimuli and react to them. Interconnected sensors and actuators that interact and react to existing risks can provide the wearer with increased safety, protection, and comfort. Thus, the skills of smart protective equipment can contribute to the reduction of errors and the number and severity of accidents in the workplace and thus promote improved performance, efficiency, and productivity. This review provides an overview and opinions of authors on the current state of knowledge on these types of technologies by reviewing and discussing the state of the art of commercially available systems and the advances made in previous research works.

scholarly journals Advanced Functional Materials for Intelligent Thermoregulation in Personal Protective Equipment

2021 ◽  
Author(s):  
Alireza Saidi ◽  
Chantal Gauvin ◽  
Safa Ladhari ◽  
Phuong Nguyen -Tri
Keyword(s):  
Personal Protective Equipment ◽  
Functional Materials ◽  
Protective Equipment ◽  
Sensors And Actuators ◽  
Physical Hazards ◽  
Current State ◽  
Smart Textile ◽  
Improved Performance ◽  
External Stimuli ◽  
Made In

The exposure to extreme temperatures in workplaces involves physical hazards for workers. A poorly acclimated worker may have lower performance and vigilance and may therefore be more exposed to accidents and injuries. Due to the incompatibility of the existing standards implemented in some workplaces and the lack of thermoregulation in many protective equipment, thermal stress remains one of the most frequent physical hazards in many work sectors. However, many of these problems can be overcome with the use of smart textile technologies that enable intelligent thermoregulation in personal protective equipment. Smart textiles can detect, react and adapt to many external stimuli. Interconnected sensors and actuators that interact and react to existing risks can provide the wearer with increased safety, protection and comfort. Thus, the skills of smart protective equipment can contribute to the reduction of errors and the number and severity of accidents in the workplace, and thus promote improved performance, efficiency and productivity.This review provides an overview and opinions of authors on the current state of knowledge on these types of technologies by reviewing and discussing the state of the art of commercially available systems and the advances made in previous research works.

scholarly journals SnS2/TiO2 Nanocomposites for Hydrogen Production and Photodegradation Under Extended Solar Irradiation

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 589
Author(s):  
Sivagowri Shanmugaratnam ◽  
Balaranjan Selvaratnam ◽  
Aravind Baride ◽  
Ranjit Koodali ◽  
Punniamoorthy Ravirajan ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Hydrogen Evolution ◽  
Environmental Remediation ◽  
High Performance ◽  
Degradation Mechanism ◽  
Solar Irradiation ◽  
Earth Abundant ◽  
Improved Performance ◽  
Chalcogenide Materials

Earth–abundant transition metal chalcogenide materials are of great research interest for energy production and environmental remediation, as they exhibit better photocatalytic activity due to their suitable electronic and optical properties. This study focuses on the photocatalytic activity of flower-like SnS2 nanoparticles (composed of nanosheet subunits) embedded in TiO2 synthesized by a facile hydrothermal method. The materials were characterized using different techniques, and their photocatalytic activity was assessed for hydrogen evolution reaction and the degradation of methylene blue. Among the catalysts studied, 10 wt. % of SnS2 loaded TiO2 nanocomposite shows an optimum hydrogen evolution rate of 195.55 µmolg−1, whereas 15 wt. % loading of SnS2 on TiO2 exhibits better performance against the degradation of methylene blue (MB) with the rate constant of 4.415 × 10−4 s−1 under solar simulated irradiation. The improved performance of these materials can be attributed to the effective photo-induced charge transfer and reduced recombination, which make these nanocomposite materials promising candidates for the development of high-performance next-generation photocatalyst materials. Further, scavenging experiments were carried out to confirm the reactive oxygen species (ROS) involved in the photocatalytic degradation. It can be observed that there was a 78% reduction in the rate of degradation when IPA was used as the scavenger, whereas around 95% reduction was attained while N2 was used as the scavenger. Notably, very low degradation (<5%) was attained when the dye alone was directly under solar irradiation. These results further validate that the •OH radical and the superoxide radicals can be acknowledged for the degradation mechanism of MB, and the enhancement of degradation efficiency may be due to the combined effect of in situ dye sensitization during the catalysis and the impregnation of low bandgap materials on TiO2.

scholarly journals The Influence of Video Format on Engagement and Performance in Online Learning

2021 ◽  
Vol 11 (2) ◽  
pp. 128
Author(s):  
Sergej Lackmann ◽  
Pierre-Majorique Léger ◽  
Patrick Charland ◽  
Caroline Aubé ◽  
Jean Talbot
Keyword(s):  
Student Performance ◽  
Cognitive Engagement ◽  
Emotional Engagement ◽  
Emotional States ◽  
Lecture Capture ◽  
Improved Performance ◽  
And Performance ◽  
Subject Experiment ◽  
The Impact ◽  
Video Format

Millions of students follow online classes which are delivered in video format. Several studies examine the impact of these video formats on engagement and learning using explicit measures and outline the need to also investigate the implicit cognitive and emotional states of online learners. Our study compared two video formats in terms of engagement (over time) and learning in a between-subject experiment. Engagement was operationalized using explicit and implicit neurophysiological measures. Twenty-six (26) subjects participated in the study and were randomly assigned to one of two conditions based on the video shown: infographic video or lecture capture. The infographic video showed animated graphics, images, and text. The lecture capture showed a professor, providing a lecture, filmed in a classroom setting. Results suggest that lecture capture triggers greater emotional engagement over a shorter period, whereas the infographic video maintains higher emotional and cognitive engagement over longer periods of time. Regarding student learning, the infographic video contributes to significantly improved performance in matters of difficult questions. Additionally, our results suggest a significant relationship between engagement and student performance. In general, the higher the engagement, the better the student performance, although, in the case of cognitive engagement, the link is quadratic (inverted U shaped).

scholarly journals Firm Level Strategy, Organization Culture and Performance of Food and Beverage Manufacturing Firms in Kenya

2018 ◽  
Vol 13 (8) ◽  
pp. 224 ◽  
Author(s):  
Zachary B. Awino ◽  
Dominic C. Muteshi ◽  
Reginah K. Kitiabi ◽  
Ganesh P. Pokhariyal
Keyword(s):  
Policy Formulation ◽  
Manufacturing Firms ◽  
Organization Culture ◽  
Hierarchical Regression ◽  
Firm Level ◽  
Food And Beverage ◽  
Improved Performance ◽  
And Performance ◽  
The Impact ◽  
The Relationship

The study tested the impact of organization culture on the on the relationship between firm-level strategy and performance of food and beverage manufacturing firms in Kenya. The opinion of the CEO/MDs from 125 firms in this sector was sought by application of a structured questionnaire; the collected data was analysed using hierarchical regression analysis. The paper stated hypothesis that organizational culture has a significant effect on the relationship between firm-level strategy and performance. The results supported the hypothesis. Therefore, firm development of strong organization culture to support firm-level strategy for higher performance is paramount. These findings will contribute to government policy formulation for sector’s expansion and competitiveness and management drives in building a positive organization culture to support firm-level strategy for improved performance.

scholarly journals Carbon Substitution on N24Cages: Crossover between Triangular and Hexagonal Structures

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Carrie Sanders ◽  
Douglas L. Strout
Keyword(s):  
Theoretical Calculations ◽  
High Energy ◽  
Energy Materials ◽  
Cylindrical Structures ◽  
High Energy Materials ◽  
Energy Applications ◽  
Carbon Substitution ◽  
Complex Forms ◽  
The Stability ◽  
Carbon Inclusion

Complex forms of nitrogen are of interest for their potential as high-energy materials, but many all-nitrogen systems lack the stability for practical high-energy applications. Inclusion of carbon atoms in an otherwise all-nitrogen structure can increase stability. Nitrogen cages are known for energetically preferring cylindrical structures with triangular endcaps, but carbon cages prefer the pentagon-hexagon structure of the fullerenes. Previous calculations on N22C2have shown that carbon inclusion narrows the gap between triangular and fullerene-like structures. In the current study, three isomers of N24are used as frameworks for carbon substitution. Theoretical calculations are carried out on isomers of N20C4, N18C6, and N16C8, with the goal of determining what level of carbon substitution causes the carbon fullerene-like structures to become energetically preferred.

Signaling sustainability: impact that learning how to report has on enrollment, endowment and emissions of North American higher education institutions

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Marcel C. Minutolo ◽  
Albena Ivanova ◽  
Michelle Cong
Keyword(s):  
Higher Education ◽  
Linear Models ◽  
Higher Education Institutions ◽  
Main Hypothesis ◽  
Signaling Mechanism ◽  
Content Type ◽  
Improved Performance ◽  
And Performance ◽  
Reporting Mechanism ◽  
The Relationship

Purpose The purpose of this paper is to develop an integrated model assessing the frequency and timing between reports on the Association for the Advancement of Sustainability in Higher Education (AASHE) Sustainability Tracking, Assessment and Rating System (STARS) reporting the framework by higher education institutions (HEIs) and the relationship between the STARS score and reputation (enrollment), finances (endowment) and performance (emissions). Design/methodology/approach The development of the theoretical model is based on learning, signaling and legitimacy theories. This study collects data from the AASHE STARS to indicate the rating level of 202 HEIs, control variables, enrollment, endowments and emissions. The hypotheses were tested using generalized linear models. Findings Findings suggest that as HEIs report on their sustainability activity, they learn to report better but that there is also an “un-learning” aspect if the HEI skips reporting in a period. The results support the main hypothesis that there is a relationship between reporting and engagement with the HEIs in the form of enrollment and endowments. Finally, the findings provide evidence that the HEIs’ reporting is associated with a reduction in emissions. Practical implications The findings suggest that HEIs should develop a reporting strategy on a standardized framework such as AASHE STARs and they ought to codify the approach to learn from prior reporting. Students and alumni are increasingly seeking to engage the HEI in the sustainability process and the report is a mechanism for signaling activities. Social implications The findings suggest that AASHE STARS scores may be used by HEIs as a signaling mechanism to stakeholders of their commitment to sustainability. The signal is a mechanism to reduce information asymmetry between the HEI and stakeholders who may want more information on the institution’s attempts toward sustainability but lack access to information. Further, HEI partners have a mechanism to assess the overall level of commitment of the HEI toward sustainability and can, therefore, engage accordingly. Originality/value There has been significant work on signaling theory and sustainability. However, the relationship between STARs reporting as a signal that legitimates the HEI, learning how to report well and HEI performance has received less attention. The current study demonstrates that the STARS framework as a reporting mechanism signals the HEIs’ level of commitment to sustainability thereby legitimating it resulting in improved performance.

Association between Participation in an Intensive Longitudinal Assessment Program and Performance on a Cognitive Examination in the Maintenance of Certification in Anesthesiology Program®

2016 ◽  
Vol 125 (5) ◽  
pp. 1046-1055 ◽  
Author(s):  
Huaping Sun ◽  
Yan Zhou ◽  
Deborah J. Culley ◽  
Cynthia A. Lien ◽  
Ann E. Harman ◽  
...  
Keyword(s):  
North Carolina ◽  
Learning Resources ◽  
Longitudinal Assessment ◽  
Immediate Feedback ◽  
High Stakes ◽  
Web Based ◽  
Maintenance Of Certification ◽  
Improved Performance ◽  
And Performance ◽  
First Time

Abstract Background As part of the Maintenance of Certification in Anesthesiology Program® (MOCA®), the American Board of Anesthesiology (Raleigh, North Carolina) developed the MOCA Minute program, a web-based intensive longitudinal assessment involving weekly questions with immediate feedback and links to learning resources. This observational study tested the hypothesis that individuals who participate in the MOCA Minute program perform better on the MOCA Cognitive Examination (CE) compared with those who do not participate. Methods Two separate cohorts of individuals eligible for July 2014 and January 2015 CEs were invited to participate in this pilot. The CE scores for each cohort were compared between those who did and did not participate, controlling for the factors known to affect performance. For the first cohort, examination performances for topics covered and not covered by the MOCA Minute were analyzed separately. Results Six hundred sixteen diplomates in July 2014 and 684 diplomates in January 2015 took the CE for the first time. In multiple regression analysis, those actively participating scored 9.9 points (95% CI, 0.8 to 18.9) and 9.3 points (95% CI, 2.3 to 16.3) higher when compared with those not enrolled, respectively. Compared to the group that did not enroll in MOCA Minute, those who enrolled but did not actively participate demonstrated no improvement in scores. MOCA Minute participation was associated with improvement in both questions covering topics included the MOCA Minute and questions not covering these topics. Conclusions This analysis provides evidence that voluntary active participation in a program featuring frequent knowledge assessments accompanied by targeted learning resources is associated with improved performance on a high-stakes CE.

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