Double layer capacitors in dye sensitized solar cells with large charge and energy storage capacity and controlled shape of output voltage signals.

The output signals in natural dyes-based solar cells (DSSC) can be either rising or decaying depending on the type of ions present in the system; these ions called added ions, are introduced by the additives: mordant and brighteners. The photon-dye interaction produces electrons, which eventually reach the electrode giving place to a superficially charged electrode in contact with an electrolyte where are the added ions. This combination produces, automatically, an electrical double-layer EDL structure which has important effects on the performance of the system: a) the added ions control, to a large extent, the initial shape of the output signal, giving rise to rising or decaying profiles; b) it is possible to store large amounts of energy and charge at high electric fields.

Piezoelectric signals of HAp and collagen with different glucose concentrations: A method for diabetes detection.

Piezoelectric signals were obtained from samples based on hydroxyapatite (HAp) and collagen (C) containing different glucose (G) concentrations. HAp was obtained by coprecipitation using Ca and HPO as precursor ions in solution. C and G were added at the beginning of the coprecipitation method during the HAp growth.

Evidence of region-wide bat population decline from long-term monitoring and Bayesian occupancy models with empirically informed priors.

Strategic conservation efforts for cryptic species, especially bats, are hindered by limited understanding of distribution and population trends. Integrating long-term encounter surveys with multi-season occupancy models provides a solution whereby inferences about changing occupancy probabilities and latent changes in abundance can be supported. When harnessed to a Bayesian inferential paradigm, this modeling framework offers flexibility for conservation programs that need to update prior model-based understanding about at-risk species with new data.

Improving geographically extensive acoustic survey designs for modeling species occurrence with imperfect detection and misidentification.

Acoustic recording units (ARUs) enable geographically extensive surveys of sensitive and elusive species. However, a hidden cost of using ARU data for modeling species occupancy is that prohibitive amounts of human verification may be required to correct species identifications made from automated software. Bat acoustic studies exemplify this challenge because large volumes of echolocation calls could be recorded and automatically classified to species.

Vocal conditioning in kea parrots (Nestor notabilis).

In laboratory studies of vocal behavior in animals, subjects are normally isolated in a sound-insulated chamber for recording, but such socially isolated conditions may reduce the chances that they will vocalize. Indeed, past studies using such methods have faced the challenge that subjects remained silent. Knowledge of conditions under which subjects are more likely to vocalize could thus improve experimental design.

Dynamic light scattering: A fast and reliable method to analyze bacterial growth during the lag phase.

A comparison between plate counting (PC) and dynamic light scattering (DLS) is reported. PC is the standard technique to determine bacterial population as a function of time; however, this method has drawbacks, such as the cumbersome preparation and handling of samples, as well as the long time required to obtain results. Alternative methods based on optical density are faster, but do not distinguish viable from non-viable cells.

Ra dynamic lixiviation from phosphogypsum samples by an automatic flow-through system with integrated renewable solid-phase extraction.

The release of Ra from phosphogypsum (PG) was evaluated by developing a novel tool for fully automated Ra lixiviation from PG integrating extraction/pre-concentration using a renewable sorbent format. Eight leached fractions (30mL each one) and a residual fraction were analyzed allowing the evaluation of dynamic lixiviation of Ra. An automatic system allows this approach coupling a homemade cell with a Ra extraction/pre-concentration method, which is carried out combining two procedures: Ra adsorption on MnO and its posterior co-precipitation with BaSO.

MSFIA-LOV system for (226)Ra isolation and pre-concentration from water samples previous radiometric detection.

An automatic system based on multisyringe flow injection analysis (MSFIA) and lab-on-valve (LOV) flow techniques for separation and pre-concentration of (226)Ra from drinking and natural water samples has been developed. The analytical protocol combines two different procedures: the Ra adsorption on MnO2 and the BaSO4 co-precipitation, achieving more selectivity especially in water samples with low radium levels. Radium is adsorbed on MnO2 deposited on macroporous of bead cellulose.

Synthesis and characterization of a HAp-based biomarker with controlled drug release for breast cancer.

A biocompatible hybrid porous polymer-ceramic material was synthesized to be used as a biomarker in the treatment of breast cancer. This device was equipped with the capacity to release medicaments locally in a controlled manner. The biomaterial was Hydroxyapatite(HAp)-based and had a controlled pore size and pore volume fraction.

Determination of lead ion removal from a flowing electrolyte in the presence of a magnetic field using Raman spectroscopy.

Purpose: The authors report on the development of a new, noninvasive method to efficiently remove metal ions in aqueous solution flowing in a tube and to quantify the concentrations of those ions. Such a technique could be used to remove toxic ions in the interiors of arteries and veins in patients intoxicated by the ingestion of metal ions.

Methods: A magnetic field is applied to an aqueous electrolyte flowing in a specially designed rectangular cell in order to deflect the ion trajectories and concentrate them at one side of a cell.

Uranium monitoring tool for rapid analysis of environmental samples based on automated liquid-liquid microextraction.

A fully automated in-syringe (IS) magnetic stirring assisted (MSA) liquid-liquid microextraction (LLME) method for uranium(VI) determination was developed, exploiting a long path-length liquid waveguide capillary cell (LWCC) with spectrophotometric detection. On-line extraction of uranium was performed within a glass syringe containing a magnetic stirrer for homogenization of the sample and the successive reagents: cyanex-272 in dodecane as extractant, EDTA as interference eliminator, hydrochloric acid to make the back-extraction of U(VI) and arsenazo-III as chromogenic reagent to accomplish the spectrophotometric detection at 655 nm. Magnetic stirring assistance was performed by a specially designed driving device placed around the syringe body creating a rotating magnetic field in the syringe, and forcing the rotation of the stirring bar located inside the syringe.

Automation of ⁹⁹Tc extraction by LOV prior ICP-MS detection: application to environmental samples.

A new, fast, automated and inexpensive sample pre-treatment method for (99)Tc determination by inductively coupled plasma-mass spectrometry (ICP-MS) detection is presented. The miniaturized approach is based on a lab-on-valve (LOV) system, allowing automatic separation and preconcentration of (99)Tc. Selectivity is provided by the solid phase extraction system used (TEVA resin) which retains selectively pertechnetate ion in diluted nitric acid solution.

Escherichia coli viability determination using dynamic light scattering: a comparison with standard methods.

To determine the concentration of bacteria in a sample is important in the food industry, medicine and biotechnology. A disadvantage of the plate-counting method is that a microorganism colony could arise from one cell or from many cells. The other standard methodology, known as optical density determination, is based on the turbidity of a suspension and registers all bacteria, dead and alive.

Scratch and abrasion properties of polyurethane-based micro- and nano-hybrid obturation materials.

Polyurethane-based micro- and nano-hybrid composites were produced with controlled porosity to be used as obturation materials. In addition to hydroxyapatite (HAp) micro-particles in the composites, two different ceramics particle types were also added: alumina micro-particles and silica nano-particles. Particles of different sizes provide the materials with improved mechanical properties: the use of micro- and nano-particles produces a better packing because the nano-particles fill the interstitial space left by the micro-particles, rendering an improvement in the mechanical properties.

Stabilized Conversion Efficiency and Dye-Sensitized Solar Cells from Beta vulgaris Pigment.

Dye-Sensitized Solar Cells (DSSCs), based on TiO(2) and assembled using a dye from Beta vulgaris extract (BVE) with Tetraethylorthosilicate (TEOS), are reported. The dye BVE/TEOS increased its UV resistance, rendering an increase in the cell lifetime; the performance of these solar cells was compared to those prepared with BVE without TEOS. The efficiency η for the solar energy conversion was, for BVE and BVE/TEOS, of 0.

Automated total and radioactive strontium separation and preconcentration in samples of environmental interest exploiting a lab-on-valve system.

A novel lab-on-valve system has been developed for strontium determination in environmental samples. Miniaturized lab-on-valve system potentially offers facilities to allow any kind of chemical and physical processes, including fluidic and microcarrier bead control, homogenous reaction and liquid-solid interaction. A rapid, inexpensive and fully automated method for the separation and preconcentration of total and radioactive strontium, using a solid phase extraction material (Sr-Resin), has been developed.

New dye-sensitized solar cells obtained from extracted bracts of Bougainvillea glabra and spectabilis betalain pigments by different purification processes.

The performance of a new dye-sensitized solar cell (DSSC) based in a natural dye extracted from the Bougainvillea spectabilis' bracts, is reported. The performance of this solar cell was compared with cells prepared using extract of the Bougainvillea glabra and mixture of both extracts; in both cases the pigments were betalains, obtained from Reddish-purple extract. These dyes were purified to different extents and used for the construction of solar cells that were electrically characterized.

(Z)-3-butylidenephthalide from Ligusticum porteri , an α-glucosidase inhibitor.

An extract from the roots of Ligusticum porteri, orally administered to groups of normal and diabetic mice, showed significant hypoglycemic and antihyperglycemic effects. Experimental type-II DM was achieved by treating mice with streptozotocin 15 min after an injection of β-nicotinamide adenine dinucleotide. (Z)-6,6',7,3'α-diligustilide (1), (Z)-ligustilide (2), 3-(Z)-butylidenephthalide (3), myristicin (4), and ferulic acid (5) were isolated from the active extract.

In vivo evaluation of implant-host tissue interaction using morphology-controlled hydroxyapatite-based biomaterials.

In medicine, micro-electro-mechanical systems (MEMS) perform several specific functions. The design of bio-packages for MEMS to be implanted into the human body has been an increasing challenge in the last years. Mechanical, chemical and thermal resistance, as well as excellent bonding to silicon surfaces, are needed.

Hydroxyapatite spheres with controlled porosity for eye ball prosthesis: processing and characterization.

Porous hydroxyapatite spheres were prepared by a modified gelcasting method producing a ceramic prosthesis with controled porosity. The spheres are approximately 2.2 cm in diameter with a relatively homogeneous pore size distribution from 10 to 40 microm in diameter.