101 research outputs found
Morphino: A nature-inspired tool for the design of shape-changing interfaces
The HCI community has a strong and growing interest in shape-changing interfaces (SCIs) that can offer dynamic af- fordance. In this context, there is an increasing need for HCI researchers and designers to form close relationships with dis- ciplines such as robotics and material science in order to be able to truly harness the state-of-the-art in morphing technolo- gies. To help these synergies arise, we present Morphino: a card-based toolkit to inspire shape-changing interface designs. Our cards bring together a collection of morphing mechanisms already established in the multidisciplinary literature and illustrate them through familiar examples from nature. We begin by detailing the design of the cards, based on a review of shape-change in nature; then, report on a series of design sessions conducted to demonstrate their usefulness in generating new ideas and in helping end-users gain a better understanding of the possibilities for shape-changing materials
Outcome of left heart mechanical valve replacement in West African children - A 15-year retrospective study
The effect of polymer/plasticiser ratio in film forming solutions on the properties of chitosan films
In this work physical-chemical properties of chitosan/ glycerol film forming solutions (FFS) and the resulting films were analysed. Solutions were prepared using different concentrations of plasticising agent (glycerol) and chitosan. Films were produced by solvent casting and equilibrated in a controlled atmosphere. FFS water activity and rheological behaviour were determined. Films water content, solubility, water vapour and oxygen permeabilities, thickness, and mechanical and thermal properties were determined. Fourier transform infrared (FTIR) spectroscopy was also used to study the chitosan/glycerol interactions.
Results demonstrate that FFS chitosan concentration influenced solutions consistency coefficient and this was related with differences in films water retention and structure. Plasticiser addition led to an increase in films moisture content, solubility and water vapour permeability, water affinity and structural changes. Films thermo-mechanical properties are significantly affected by both chitosan and glycerol addition. FTIR experiments confirm these results.
This work highlights the importance of glycerol and water plasticisation in films properties.This work was supported by National Funds from FCT - Fundacao para a Ciencia e a Tecnologia, through project PEst-OE/EQB/LA0016/2011.Authors Joana F. Fundo, Andrea C. Galvis-Sanchez and Mafalda A. C. Quintas acknowledge FCT for research grants SFRH/ BD / 62176 / 2009, SFRH/BPD/37890/2007 and SFRH / BPD / 41715 / 2007, respectively
Observing the temperature dependent transition of the GP2 peptide using terahertz spectroscopy
The GP2 peptide is derived from the Human Epidermal growth factor Receptor 2 (HER2/nue), a marker protein for breast cancer present in saliva. In this paper we study the temperature dependent behavior of hydrated GP2 at terahertz frequencies and find that the peptide undergoes a dynamic transition between 200 and 220 K. By fitting suitable molecular models to the frequency response we determine the molecular processes involved above and below the transition temperature (TD). In particular, we show that below TD the dynamic transition is dominated by a simple harmonic vibration with a slow and temperature dependent relaxation time constant and that above TD, the dynamic behavior is governed by two oscillators, one of which has a fast and temperature independent relaxation time constant and the other of which is a heavily damped oscillator with a slow and temperature dependent time constant. Furthermore a red shifting of the characteristic frequency of the damped oscillator was observed, confirming the presence of a non-harmonic vibration potential. Our measurements and modeling of GP2 highlight the unique capabilities of THz spectroscopy for protein characterization.Yiwen Sun, Zexuan Zhu, Siping Chen, Jega Balakrishnan, Derek Abbott, Anil T. Ahuja and Emma Pickwell-MacPherso
What Drives the Productive Efficiency of a Firm? The Importance of Industry, Location, R&D, and Size
Long-term variability of supratidal coastal boulder activation in Brittany (France)
High-energy supratidal coastal boulder deposit (SCBD) dynamics were investigated on Vierge Island and Pors Carn Point, north and south of western Brittany, France, respectively. Morphological changes induced by boulder transport and quarrying were quantified using high-resolution topographic survey data taken between 2012 and 2017. Additional in-situ wave parameters and water levels were also recorded over this period (2014-2017) in order to compute the maximum water levels and assess the relationship between SCBD morphological changes and specific hydrodynamic conditions. During extreme water levels (for maximum water levels exceeding a one in ten year event), SCBDs were broadly reworked (up to 40% of the total volume). During lower intensity events, for which maximum water levels were still very high, morphological changes represented 1% to 5% of the total volume. These morphological and hydrodynamic observations were then used to calibrate a chronology of SCBD activation events based on 70 years of hindcast winter maximum water levels. These long-term time-series showed great interannual variability in SCBD activation but no significant long-term trend. Winter-frequency SCBD activation was better correlated to the WEPA index (r = 0.46) than the NAO index (r = 0.1). Therefore, the WEPA index can be considered to be a more significant climate proxy for assessing storm-related geomorphic changes in the temperate latitudes of the N-E Atlantic basin (36 degrees-52 degrees N), including the Brittany coast. The potential of SCBDs as a morphological storm proxy for macrotidal high-energy rocky coasts is addressed
Contaminants chimiques organiques des œufs de poule pondeuse : aspects réglementaires, modalités et risques de transfert
Le présent article fait le point sur les contaminants chimiques organiques potentiellement présents dans les œufs de poules pondeuses. Ils ont pour origine soit des médicaments vétérinaires, des additifs introduits dans les aliments, des pesticides utilisés pour la production des matières premières entrant dans l’alimentation des animaux ou encore des polluants rémanents de l’environnement. Les médicaments vétérinaires et additifs alimentaires font l’objet d’études strictes de transfert avant d’être autorisés et les résultats d’enquêtes ou de contrôles officiels montrent que les limites maximales de résidus sont très rarement dépassées dans les œufs. Les non conformités ont en général pour origine une utilisation inadéquate de la molécule, ou des contaminations croisées lors de la fabrication des aliments, notamment pour les anticoccidiens. Les pesticides utilisés pour la production de matières premières entrant dans l’alimentation des animaux font également l’objet d’une étude d’évaluation du risque de transfert avant leur autorisation. L’exposition des animaux aux contaminants de l’environnement est plus difficilement contrôlable, notamment dans les élevages en plein air, et des dépassements importants des teneurs maximales autorisées pour les dioxines, furanes ou polychlorobiphényles sont parfois rencontrés dans ce type d’élevage. Les cas les plus préoccupants émanent d’élevages de particuliers, dans lesquels certaines pratiques semblent favoriser l’ingestion de matrices, notamment de sol, en quantités importantes. Afin de prévenir le risque de transfert de ces contaminants, il est important d’évaluer l’impact de ces pratiques sur l’exposition des animaux et de quantifier l’impact de la matrice sol sur le transfert des contaminants ingérés vers l’œuf.The current paper reviews current knowledge on the organic chemical contaminants that may be present in hen eggs. They originate either from veterinary drugs or feed additives, from pesticides used for cereals production or from persistent pollutants of the environment. Carry-over studies are carried out before veterinary drugs and additives are allowed. For these compounds, official surveys reveal concentrations that are barely over the maximal residues limits. Excessive concentrations may be detected only in cases of inappropriate use of veterinary drugs or of cross contamination during feed processing, especially for coccidiostats. Carry-over experiments are also conducted before allowing pesticides to be used for cereal production. Effective control against environmental contaminants for animals raised outdoors is not easy. In fact, concentrations of dioxins, furans and polychlorobiphenyls exceeding the maximum concentrations permitted in eggs have been rarely recorded. The worst cases arise in home-produced eggs, probably as a result of practices that stimulate ingestion of environmental matrices, especially soil. In order to prevent the risk of the presence of such contaminants in eggs, factors affecting soil ingestion in animals raised outdoors should be better understood, and the impact of soil on the carry-over of ingested contaminants to eggs should be quantified
Crispness: a critical review on sensory and material science approaches
International audienceMany texture studies have been published on crispness because of the great interest of consumers towards crispy foods. This work reviews the existing literature on the topic, and especially the different approaches, instrumental and sensory, applied to study crispness. These studies result in a wide range of data but, because crispness is not a clearly defined sensory attribute, the conclusions that can be drawn from these studies should be carefully examined. The physical basis for crispness are discussed and the role of structure, hydration and ingredients on crispness and its stability are presented
Study of release kinetics of small and high molecular weight substances dispersed into spray-dried ethylcellulose microspheres.
Spray-dried ethylcellulose microspheres were used as matrices for the encapsulation of a fungal lactase and/or small paramagnetic probes (Tempol or Tempo). Their dissolution in water was studied. Kinetics fitted with the model Q = kt(n) of Korsemeyer et al. [Int. J. Pharm. 15 (1983) 25] exhibited a non-Fickian diffusion. The calculated diffusional exponent (n) values were near 0.26 whatever the encapsulated probes. The release rates (k) were only slightly different for paramagnetic probes and lactase. This result indicated that the probes' release mechanisms are not diffusion controlled. Other factors such as matrix porosity and probe solubility in the matrix and in water could influence the probes' release rate
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