Inextensible Surface Reconstruction Under Small Relative Deformations from Distributed Angle Measurements

International Journal of Computer Vision - A mathematical model to measure the shape of a 3D surface using angle measurements from embedded sensors is presented. The surface is known in a reference...     

Hot-Water Extraction Optimization of Sugar Maple (Acer saccharum Marsh.) and Red Maple (Acer rubrum L.) Bark Applying Principal Component Analysis

In the forest industry, bark is an abundant residue, predominantly converted into calorific energy. As the antioxidant potential of phenolic compounds from sugar maple (Acer saccharum Marsh.) and red maple (Acer rubrum L.) bark has previously been established, the present study focused on the hot-water extraction optimization of these barks. Several process parameters (maple species, temperature, duration, ratio bark/water, particle size) were thus studied and large disparities were found between the two species. Extraction yield, phenolic content, and antioxidant capacity of red maple extracts were several times higher than those of sugar maple extracts. Principal component analysis, applied to the selected best extraction conditions, identified 3–4 clusters depending on the maple species. These groups were sorted from the highest extraction yield and energy consumption combined with the lowest phenolic content and antioxidant capacity, to moderate extraction yield and energy consumption with the highest phenolic content and antioxidant capacity.     

Impact of oxygen concentration during the deposition of window layers on lowering the metastability effects in Cu(In,Ga)Se2/CBD Zn(S,O) based solar cell

The purpose of the present paper is to focus on the impact of oxygen gas partial pressure during the sputtering of i‐ZnO and ZnMgO on the transient behavior of Cu(In,Ga)Se₂ (CIGSe) based solar cells parameters when a CBD‐Zn(S,O) buffer layer is used. Based on electrical characterization of cells, it is observed that the effect of light soaking is different on J–V characteristics depending on whether oxygen is or is not present during the first deposition time of the i‐ZnO or ZnMgO layers. In fact, when cells are prepared with standard i‐ZnO, the efficiencies are very low and a pronounced transient behavior is observed. However, when the first 10 nm of i‐ZnO or ZnMgO is formed by sputtered layer without adding oxygen during the process, depending on the thickness of the buffer layer, the transient effects strongly decreases. It is then possible to get stable cells reaching efficiencies quite similar to the CdS reference cells, especially with ZnMgO, without any post‐treatments. Copyright © 2015 John Wiley & Sons, Ltd.     

Experimental investigations and numerical analysis for improving knowledge of incremental sheet forming process for sheet metal parts

The paper is related to the analysis of shape distortions and springback effects arising in single point incremental sheet forming in order to study the use of a FE model based on shell elements to perform simulation of the process. A comparison between numerical and experimental results is made to assess the suitability of the model. The measurements of geometrical profile of a truncated cone and springback of cut rings show that the FE model allows to predict accurate results for a set of well defined process parameters. The deformation mechanism of ISF is taken into consideration to determine the limits of the model studied.     

One‐Pot Synthesis of Functional Helicoidal Hybrid Organic–Inorganic Nanofibers with Periodically Organized Mesoporosity

The one‐pot synthesis and properties of multifunctional hybrid mesoporous organosilica fibers with helical shapes are described. These hybrid mesoporous fibers are prepared without chiral elements and functionalized with a large variety of organic R functions (R = alkylthiols, phenylsulfonates, alkylphosphonates, dansyl, aminopropyl, fluoroalkyl, etc.). The resulting nanomaterials are thoroughly characterized by a variety of techniques. The use of a synergetic combination of achiral molecules as co‐directing structuring agents, a surfactant, and an organofunctional silica precursor R‐Si(OR)₃ allows, via carefully tuning of the main synthesis parameters and processing conditions, to control the shape, which is the anisotropic factor, of the hybrid nanofibers. The functionalization of the hybrid materials with fluorescent molecules (dansyl) and gold nanoparticles opens possibilities for sensor and catalytic applications, respectively. Moreover, these hybrid nanofibers can be easily transferred in organic solvents or in a “green” solvent such as water to make stable colloidal dispersions. This tunable functionality of nanofibers also allows their transferability into a variety of polymeric hosts (PVDF, PVBu, and PVP) allowing the formation of functional homogeneous nanocomposite hybrid membranes.     

Influence of Silicification on the Structural and Biological Properties of Buffer‐Mediated Collagen Hydrogels

A buffer‐mediated gelation route for collagen hydrogels that allows the formation of homogeneous composite and hybrid materials with various silica sources (i.e., colloidal silica and soluble silicates) at high concentration (up to 25 × 10^?3 M ) is described. Most significant improvement in rheological properties and proliferation of primary adult human dermal fibroblasts was obtained for the silicate‐based hybrid materials. A similar trend was observed in composite materials incorporating 14 nm SiO₂ nanoparticles, although to a much lesser extent, whereas larger colloids (80 and 390 nm) did not significantly impact mechanical stability and cell behavior. Modification of 80 nm particles surface with amine groups weakens the collagen‐mineral interface, resulting in the decrease of material stability and leading to particle aggregation during the course of cell proliferation experiments.     

Diagnosis of phenylketonuria in a 35-year-old mother in relation to prenatal diagnosis of intrauterine growth retardation with microcephaly

BACKGROUND: Some French pregnant women with phenylketonuria (PKU), born before 1978, have not been tested with the Guthrie method during the neonatal period. They have a risk of spontaneous abortion and their infants are often mentally retarded with microcephaly and/or congenital heart anomaly. CASE REPORT: A woman with a moderate mental retardation became pregnant at the age of 31 years. Her newborn had a severe intrauterine growth retardation with microcephaly and developed mental retardation. This mother became pregnant again 4 years later. Repeated fetal ultrasonography showed progressive growth retardation. Maternal blood phenylalanine concentration was 18 mg/100 mL. Therapeutic abortion at 27 weeks of gestational age showed a fetus with several abnormalities, particularly cardiovascular and cerebral. CONCLUSION: It is still possible to meet women with unrecognized atypical PKU. Fetus or infant born with unexplained growth retardation and microcephaly requires search for maternal PKU.     

Identification and disruption of a plant shaker-like outward channel involved in K+ release into the xylem sap

SKOR, a K+ channel identified in Arabidopsis, displays the typical hydrophobic core of the Shaker channel superfamily, a cyclic nucleotide-binding domain, and an ankyrin domain. Expression in Xenopus oocytes identified SKOR as the first member of the Shaker family in plants to be endowed with outwardly rectifying properties. SKOR expression is localized in root stelar tissues. A knockout mutant shows both lower shoot K+ content and lower xylem sap K+ concentration, indicating that SKOR is involved in K+ release into the xylem sap toward the shoots. SKOR expression is strongly inhibited by the stress phytohormone abscisic acid, supporting the hypothesis that control of K+ translocation toward the shoots is part of the plant response to water stress.     

Cyanobacteria as bioreactors for the synthesis of Au, Ag, Pd, and Pt nanoparticles via an enzyme-mediated route

Common Anabaena, Calothrix, and Leptolyngbya cyanobacteria are shown to form Au, Ag, Pd, and Pt nanoparticles of well-controlled size. These nanoparticles are synthesized intra-cellularly, and naturally released in the culture medium, where they are stabilized by algal polysaccharides, allowing their easy recovery. The size of the recovered particles as well as the reaction yield is shown to depend on the cyanobacteria genus. Investigations of nanoparticle formation indicate that the intracellular nitrogenase enzyme is responsible for the metal reduction but that the cellular environment is involved in the colloid growth process.