Fuzzy approach to business improvement of holding equipment in the conditions of decreased production range

In recent years, manufacturing industry has been characterized by a decreased production range and a demand for a rapid change of production programs. In such conditions holding equipment costs are considerably larger. In this paper, we review and analyze possible ways of business improvement concerning holding equipment in specific production conditions characterized by the decreased production range and lack of financial sources for applying systems of assembled and disassembled equipment. Classification of elements and group of elements of those systems is performed by applying a new fuzzy ABC method presented in this paper. Selected optimization criteria describe the performance measures of elements and group of elements of assembled and disassembled equipment whereas their relative weights are not the same. It is assumed that the values of imprecise optimization criteria and their relative weights are described by discrete fuzzy numbers. The developed procedure is illustrated by an example with real input data

Nickel Manganite-Sodium Alginate Nano-Biocomposite for Temperature Sensing

Nanocrystalline nickel manganite (NiMn2O4) powder with a pure cubic spinel phase structure was synthesized via sol-gel combustion and characterized with XRD, FT-IR, XPS and SEM. The powder was mixed with sodium alginate gel to form a nano-biocomposite gel, dried at room temperature to form a thick film and characterized with FT-IR and SEM. DC resistance and AC impedance of sensor test structures obtained by drop casting the nano-biocomposite gel onto test interdigitated PdAg electrodes on an alumina substrate were measured in the temperature range of 20-50 degrees C at a constant relative humidity (RH) of 50% and at room temperature (25 degrees C) in the RH range of 40-90%. The material constant obtained from the measured decrease in resistance with temperature was determined to be 4523 K, while the temperature sensitivity at room temperature (25 degrees C) was -5.09%/K. Analysis of the complex impedance plots showed a dominant influence of grains. The decrease in complex impedance with increase in temperature confirmed the negative temperature coefficient effect. The grain resistance and grain relaxation frequency were determined using an equivalent circuit. The activation energy for conduction was determined as 0.45 eV from the temperature dependence of the grain resistance according to the small polaron hopping model, while the activation energy for relaxation was 0.43 eV determined from the Arrhenius dependence of the grain relaxation frequency on temperature

The effect of pH on visible-light photocatalytic properties of pseudobrookite nanoparticles

In this study, pseudobrookite (Fe2TiO5) nanoparticles were fabricated by a modified sol-gel method using Fe(NO3)39H2O and Ti(OC3H7)4 as starting reagents and ethanol as solvent. Oxalic acid was used as a chelating agent while cetyltrimethyammonium bromide (CTAB) and citric monohydrate were used as surfactants. Structral and morphological characterization using X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) analysis confirmed the formation of pseudobrookite nanoparticles. As synthetized Fe2TiO5 nanoparticles were utilized as photocatalysts for decolorisation of Methylene blue (MB) under visible light irradiation. It was observed that the adsorption of MB onto Fe2TiO5 nanoparticles is strongly dependent on the solution pH. Maximum decolorozation was observed for Fe2TiO5 nanoparticles prepared with CTAB under alcaline conditions (pH=10.5)

Nanocrystalline iron-manganite (FeMnO3) applied for humidity sensing

Nanocrystalline iron manganite was synthesized using a sol-gel self-combustion method with glycine as fuel, followed by calcination at 900 °C for 8 hours. Structural characterization was performed using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). It confirmed the formation of nanocrystalline iron-manganite with a perovskite structure. Humidity sensing properties of bulk and thick film samples of the obtained nanocrystalline iron manganite powder were analyzed. Organic vehicles were added to the powder to form a thick film paste that was screen printed on alumina substrate with test PdAg interdigitated electrodes. Impedance response of bulk and thick film samples was analyzed in a humidity chamber in the relative humidity range 30-90% in the frequency range 42 Hz to 1 MHz in view of applying iron-manganite for humidity sensing applications

2-OXO-1,2,3,4-tetrahydropyrimidine-azo-pyridone dye : a potential application as new green-emitting fluorescent probe

Molecular imaging is a relatively new research field, which has demonstrated great potential, especially in clinical oncology – from drug development to cancer early detection. The key of fluorescence imaging is the construction of fluorescent probe which is composed of two parts, the recognition groups to recognize cancer cells, and fluorophores to signal the recognition events. In this research, the structure of new fluorescent azo dye based on 2-oxo-1,2,3,4-tetrahydropyrimidin and 2-pyridone moieties has been reported. The absorption and emission properties of the investigated azo dye have been studied using UV-Vis and fluorescence spectroscopy. The obtained results suggest that studied dye meets the requirements for new green-emitting fluorescent probe, suitable for further application in biomedical researches

Structure and photocatalytic properties of sol-gel synthesized pseudobrookite

Fe2TiO5 nanopartcles were synthesized by modified sol-gel method with aid of Fe(NO3)3 9H2O and Ti(OC3H7)4 as starting reagents, oxalic acid as chilate agent and cetyltrimethylammonium bromide as surfactant. The aim of this study was to asses the photocatalytic degradaton of the antibiotic Oxytetracycline (OTC) using visible light irradiation. As prepared nanoparticles were characterized by XRD, BET, FESEM and UV-vis DRS. The optimal operating conditions of oxytetracycline photocatalytic degradation were achived by changing the pH of the solution and changing the concentration of photocatalyst

Structure, morphology and photocatalytic properties of CoxMg1-xFe2O4 (0<x<1) spinel ferrites obtained by sol-gel synthesis

Nanocrystalline cobalt magnesium ferrites with varying cobalt and magnesium content (CoxMg1-xFe2O4, 0<x<1) were synthesized using the sol-gel self-combustion method with citric acid as fuel, followed by calcination at 700 C for 2 hours. Structural characterization was performed using Xray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and Raman spectroscopy. It confirmed the formation of agglomerated nanocrystalline ferrites with an inverse cubic spinel structure. The optical band gap energy was determined using UV/Vis spectrophotometry. It reduced with increased Co content. Visible light photocatalytic activity was tested using natural and artificial light sources through a series of experimental degradations of the methylene blue (MB) solution

Influence of Fe Doping on the Crystal Structure and Optical Properties of Mechanically Activated SrTiO3 Powders

Iron-doped strontium-titanate (SrTiO3) powders with various iron(III) oxide (Fe2O3) weight percentages (1.5, 3 and 6 wt%) were prepared by a solid-state method in the presence of mechanical activation (10, 30 and 120 min). A systematic investigation by XRD, SEM and Raman spectroscopy has been undertaken to evaluate the role of dopant on the microstructural and morphological study of the perovskite oxide obtained. The optical properties of the different iron-doped and activated Fe-SrTiO3 powders have been also evaluated. The results demonstrated that Fe has been substituted into the lattice and surface layers of particles of SrTiO3 powders and the absorption edge shifted to higher wavelength values with increasing activation time and dopant weight percentage. The lowest value of the band gap (Eg=3.20 eV) was registered for the longest activation (120 min) and the highest weight percentage of dopant (6 wt%). Combining doping with mechanical activation, led to lower values of Eg and that fact could be used in subsequent studies to make Fe-SrTiO3 more suitable photocatalysts

Photocatalytic degradation of methylene blue and oxytetracycline via sol-gel synthesized pseudobrookite

Fe2TiO5 nanoparticles were synthesized by modified sol-gel method using Fe(NO3)3×9H2O and Ti(OC3H7)4 as starting reagents, oxalic acid as chilate agent and cetyltrimethylammonium bromide as surfactant. The aim of this study was to asses the photocatalytic degradaton of water pollutants, methylene blue and the antibiotic Oxytetracycline (OTC) using natural sunlight irradiation. As prepared nanoparticles were characterized by XRD, BET, FESEM and UV-vis DRS. The optimal operating conditions of photocatalytic degradation of water pollutants were achived by changing the pH of the solution and changing the concentration of photocatalyst