Giant piezoelectricity on Si for hyperactive MEMS

Microelectromechanical systems (MEMS) incorporating active piezoelectric layers offer integrated actuation, sensing, and transduction. The broad implementation of such active MEMS has long been constrained by the inability to integrate materials with giant piezoelectric response, such as Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) (PMN-PT). We synthesized high-quality PMN-PT epitaxial thin films on vicinal (001) Si wafers with the use of an epitaxial (001) SrTiO(3) template layer with superior piezoelectric coefficients (e(31,f) = -27 ± 3 coulombs per square meter) and figures of merit for piezoelectric energy-harvesting systems. We have incorporated these heterostructures into microcantilevers that are actuated with extremely low drive voltage due to thin-film piezoelectric properties that rival bulk PMN-PT single crystals. These epitaxial heterostructures exhibit very large electromechanical coupling for ultrasound medical imaging, microfluidic control, mechanical sensing, and energy harvesting.     

Fluorometric detection of enzyme activity with synthetic supramolecular pores

The reversible blockage of synthetic pores formed by rigid-rod beta barrels, either by substrates or products, was used to sense a variety of enzymatic reactions in high-throughput format with "naked-eye" fluorescent detection. Improvement of sensor sensitivity beyond three orders of magnitude by straightforward internal mutations underscores the functional plasticity of rigid-rod beta barrels. Such detectors of enzyme activity with the aforementioned characteristics are needed in areas as diverse as proteomics and environmentally benign organic synthesis.     

Effect of chemically modified date palm leaf fiber on mechanical,thermal and rheological properties of polyvinylpyrrolidone

Polyvinylpyrrolidone/date palm leaf fiber (PVP/DPL) biocomposites were prepared by melt mixing fabrication technique with different weight percentage of fibers. DPL fibers were chemically modified by acrylic acid in order to have better dispersion and compatibility with PVP matrix. The interaction of DPL fibers with PVP matrix was studied by Fourier transforms infrared spectroscopy (FTIR). Field emission scanning electron microscope (FESEM) was used for the study the morphology of chemically modified DPL fibers and PVP/DPL biocomposites. Mechanical properties were improved with fiber loading due to strong interfacial adhesion between PVP and DPL fibers. The storage modulus, loss modulus and tan delta values of PVA/DPL biocomposites were measured by DMTA. The rheological properties were investigated to study the shearing storage and loss modulii along with complex viscosity of biocomposites. The thermal and conducting properties of biocomposites were measured and compared with that of virgin PVP.     

Zn, Cu, Cd and Hg binding to metallothioneins in harbour porpoises Phocoena phocoena from the southern North Sea

Background  

Harbour porpoises Phocoena phocoena from the southern North Sea are known to display high levels of Zn and Hg in their tissues linked to their nutritional status (emaciation). The question arises regarding a potential role of metallothioneins (MTs) with regard to these high metal levels. In the present study, metallothionein detection and associated Zn, Cd, Cu and Hg concentrations were investigated in the liver and kidney of 14 harbour porpoises collected along the Belgian coast.     

Effect of efficient pectinolytic bacterial isolates on retting and fibre quality of jute

Four bacterial strains with high balanced polygalacturonase (PG) and pectin lyase (PNL), and xylanase with minimal cellulase activity were used in jute retting. The 16S rDNA analysis revealed that the organisms were: Bacillus sp. L6 (GQ891097), Bacillus pumilus strain EK-17 (GQ891098), B. pumilus strain Geo-03-422 (GQ891103) and B. pumilus strain IK-MB12-518F (GQ891105). The microorganisms in different combinations of consortia showed synergistic effect resulting in increased PG (35.52-46.61 IU/g cell wet weight), PNL (39.79-72.12 U/ml), xylanase (0.705-0.840 μmol/ml/min) and little cellulase (0-0.153 μmol/ml/min) activities. The organisms in different combinations of consortia reduced the retting period from 11 to 13 days as compared to 19 days in the control. Microbial inoculation produced remarkable improvement in jute fibre strength (26.62-28.91 g/tex) and fineness (2.76-2.92 tex) over control. The pH of the post-retting water samples became acidic, and the electrical conductivity (Ec), chemical oxygen demand (COD) and hardness increased. The organisms could be adopted in industrial application for extraction of jute fibre.     

Hydrus-1D model for simulating water flow through paddy soils under alternate wetting and drying irrigation practice

Paddy and Water Environment - Alternate wetting and drying (AWD) irrigation practice in paddy cultivation requires a safe soil moisture stress level in the root zone for which irrigation water...     

Engineering design of woven fabrics using non-traditional optimization methods: A comparative study

This work aims to design woven fabrics with desired quality at optimum manufacturing cost by choice of suitable weaving parameters such as count, crimp and thread spacing of warp and weft yarns. To fulfill this goal, we endeavor to devise search based non-traditional optimization methods such as genetic algorithm, particle swarm optimization and simulated annealing for efficiently finding the appropriate combination of weave parameters. The quick response capability of the non-traditional optimization methods would benefit the fabric manufacturers for efficient determination of the required weaving parameters to produce the engineered fabrics. The experimental validation confirms that the particle swarm optimization is most suitable technique for engineering design of woven fabrics.     

Hemagglutinins in vegetative tissues of Bengal gram

Hemagglutinating activity was identified in the roots and vegetative tissues of Bengal gram using rabbit erythrocytes. The activity in the roots appears to be similar to that of the seeds in respect to their sugar inhibition property. Seed and root extracts were found to have fetuin inhibitory agglutinating activity, whereas cotyledons showed different sugar specificity. However, 7-day cotyledons and roots from 3 and 7-day plants were also found to have galactose and N-acetyl-D-galactosamine inhibitory activity. Protein profile in different tissues during their developmental stages was analyzed by SDS-PAGE. A major band at 66 kDa was common to all tissues at different stages of their development except 3-day cotyledons where 2 major bands at 22 kDa and 74 kDa were observed. Two prominent bands at 74 kDa and 86 kDa were found along with 60 kDa protein in 3-day old roots whereas a major band at 33 kDa was found in 15-day old roots. Total protein content and specific activity of hemagglutinin were measured. Increase in specific activity with lower protein content was observed in cotyledons of 15-day old plant. Specific activity was eight times higher in the roots and four times more in leaf tissues of 7-day old plants in comparison to 15-day old plants. Stems also showed a significant increase of specific activity (p = 0.013) in 7-day old plants without any significant alteration in the protein content.     

Suppression of Botryosphaeria canker of apple by arbuscular mycorrhizal fungi

Stem brown canker or Botryosphaeria canker disease impairs the growth and kills the shoots, limbs and even trunks of infected apple trees. Apple roots are usually colonized by arbuscular mycorrhizal fungi, which may have a positive influence on plant growth and suppression of diseases. In order to assess the efficacy of AM to suppress the disease severity and plant growth enhancement, nine AMF inoculation treatments (Sclerocystis dussi, Glomus intraradices, G. fasciculatum, G. bagyaraji, G. leptotichum, G. monosporum, Gigaspora margarita, a mixed AM culture and a non-mycorrhizal control treatment) were used in this present study. Two-year-old potted apple plants, maintained under glasshouse conditions, were either pre-inoculated with AMF followed by stem inoculation with Botryosphaeria ribis or simultaneously inoculated with Botryosphaeria ribis and AM. The results indicated that the incidence of canker was less severe in plants inoculated with AMF in comparison to non-mycorrhizal control. Timing of inoculation also had a significant effect on disease development and plant survival. Plants pre-inoculated with mycorrhiza performed better over those inoculated simultaneously with Botryosphaeria ribis and AM fungi. Furthermore, AM inoculation resulted in improved survival and growth of AMF-colonized plants; though, it varied by species of AM fungi utilized.     

Long-term feeding ecology and habitat use in harbour porpoises Phocoena phocoena from Scandinavian waters inferred from trace elements and stable isotopes

Background  

We investigated the feeding ecology and habitat use of 32 harbour porpoises by-caught in 4 localities along the Scandinavian coast from the North Sea to the Barents Sea using time-integrative markers: stable isotopes (δ¹³C, δ¹⁵N) and trace elements (Zn, Cu, Fe, Se, total Hg and Cd), in relation to habitat characteristics (bathymetry) and geographic position (latitude).