Search results for "surface"
showing 10 items of 9345 documents
Thixotropic Behavior of Salad Dressings Stabilized with Modified Starch, Pectin, and Gellan Gum. Influence of Temperature
2008
The thixotropy of low‐oil salad dressing has been analyzed at different temperatures (8–26°C). The usual formulation containing modified starch (4%) was compared with others in which part of the starch had been substituted by pectin (0.5%) or different concentrations of gellan (0.1 and 0.5%). Up and down flow curves were measured, showing in all cases shear thinning behavior and fitting the Herschel‐Bulkley model. Thixotropic areas enclosed by the up curve and the corresponding different down curves, STh, were obtained. With the aim of establishing comparative results, and since the viscosities were quite different, the parameter considered was relative thixotropic area, SR (%)=100 (STh/Sup…
Spin-valve current sensor for industrial applications
2003
This work presents an industrial application of a new spin-valve current sensor based on the giant magnetoresistance effect (GMR) and provides a comparison between this sensor and the typical sensor used in these applications, the hall sensor. Experimental results derived from the application of this two sensors in a power application (a bi-directional three-phase rectifier) are shown.
Toward development of optical biosensors based on photoluminescence of TiO2 nanoparticles for the detection of Salmonella
2017
Quality control of food and agriculture production is an inseparable part of human safety and wellbeing. Salmonella infections belong to one of the most monitored pathogens in the world, therefore advanced determination of this pathogen can decrease the risks of human diseases caused by this microorganism. In this research we introduce a novel optical immunosensor for determination of Salmonella typhimurium. The immunosensor is based on Titanium dioxide (TiO2) nanoparticles deposited on glass substrates (glass/TiO2)center dot TiO2 nanoparticles exhibit an intense photoluminescence (PL) in the visible range of spectrum at room temperature. The direct immobilization of antibodies (anti-S-Ab) …
A study of electron transfer in Ru(dcbpy)2(NCS)2 sensitized nanocrystalline TiO2 and SnO2 films induced by red-wing excitation.
2008
Excited state dynamics and electron transfer from the Ru(dcbpy)2(NCS)2 (RuN3) sensitizer to semiconductor nanoparticles were studied using time-resolved femtosecond absorption spectroscopy. We found that excitation of the red wing of the absorption spectrum of the sensitizer populates the (3)MLCT state directly, both in solution and attached on semiconductor nanoparticle films. Electron injection is slowed down and becomes gradually less efficient as excitation moves towards red from the absorption maximum at 535 nm. At 675 nm the injection is non-exponential and characterized by 5, 30 and 180 ps time constants. The non-exponential electron injection observed is assigned to injection from a…
A new biodegradable and biocompatible hydrogel with polyaminoacid structure
2007
The preparation and physicochemical and biological characterization of a novel polyaminoacid hydrogel have been reported. The ,-poly(N-2- hydroxyethyl)-dl-aspartamide (PHEA) has been used as a starting polymer for a derivatization reaction with methacrylic anhydride (MA) to give rise to the methacrylate derivative named PHM. Photocrosslinking of PHM has been performed in aqueous solution at 313 nm and in the absence of toxic initiators. PHM-based hydrogel has been characterized by scanning electron microscopy, X-ray diffractometry, swelling measurements in aqueous media; the degradation of PHM-based hydrogel has been evaluated as a function of time in the absence or in the presence of ester…
Non-cross-linked collagen type I/III materials enhance cell proliferation: in vitro and in vivo evidence
2014
Objective: To analyze Mucograft®(MG), a recently introduced collagen matrix, in vitro and in vivo, and compare it with BioGide®(BG), a well-established collagen membrane, as control. Material and Methods: A detailed analysis of the materials surface and ultra-structure was performed. Cellular growth patterns and proliferation rates of human fibroblasts on MG and BG were analyzed in vitro. In addition, the early tissue reaction of CD-1 mouse to these materials was analyzed by means of histological and histomorphometrical analysis. Results: MG showed a three-fold higher thickness both in dry and wet conditions, when compared to BG. The spongy surface of BG significantly differed from that of …
Analysis of complex autoantibody repertoires by surface-enhanced laser desorption/ionization-time of flight mass spectrometry
2003
Normal sera contain a large number of naturally occurring autoantibodies which can mask important disease-associated ones. Western blotting has evolved as the most important tool to demonstrate autoantibodies in autoimmune diseases, because of its ability to simultaneous screening for a wide spectrum of different antigens. In previous studies we have shown the diagnostic potential of the analysis of autoantibodies in autoimmune diseases by means of multivariate statistics and artificial neural networks. However, the Western blotting procedure remains very time-consuming and is also limited in sensitivity. Therefore, we used an on-chip approach for the analysis of autoantibodies. This Protei…
Micellar liquid chromatography in doping control.
2010
The issue of doping control in sport involves the development of reliable analytical procedures and efficient strategies to process a large number of samples in a short period of time. Reversed-phase LC techniques with aqueous–organic mobile phases and MS or diode-array detection yield satisfactory results for the identification of prohibited substances in sport. However, time-consuming sample pretreatment steps are required, which reduces sample throughput. Micellar LC (MLC) that uses hybrid mobile phases of surfactant above its critical micellar concentration and organic solvent has been revealed as an interesting alternative. The surfactant sodium dodecyl sulfate solubilizes the protein…
Visual data mining with self-organising maps for ventricular fibrillation analysis
2012
Detection of ventricular fibrillation (VF) at an early stage is being deeply studied in order to lower the risk of sudden death and allows the specialist to have greater reaction time to give the patient a good recovering therapy. Some works are focusing on detecting VF based on numerical analysis of time-frequency distributions, but in general the methods used do not provide insight into the problem. However, this study proposes a new methodology in order to obtain information about this problem. This work uses a supervised self-organising map (SOM) to obtain visually information among four important groups of patients: VF (ventricular fibrillation), VT (ventricular tachycardia), HP (healt…
Supercritical carbon dioxide extraction of seed oil from yellow horn (Xanthoceras sorbifolia Bunge.) and its anti-oxidant activity
2010
Supercritical fluid carbon dioxide (SF-CO(2)) extraction (SFE) of seed oil from yellow horn and its anti-oxidant activity were investigated. The effects of CO(2) flow rate and particle size were firstly optimized, and a central composite design (CCD) combined with response surface methodology was used to study the effects of extraction pressure, temperature and time on the extraction yields. A maximal extraction yield of 61.28% was achieved under optimal conditions of extraction pressure 30 MPa at 45.68 degrees C, 2.08 h and CO(2) flow rate 12 kg/h with 0.5mm particle size. By analyzing the chemical composition of the seed oil, we found that the content of unsaturated fatty acids was approx…