Possibility Of Temperature Control Research Articles

INFLUENCE OF CHANGE IN PRESSURE DURING THE KNEADING OF THE DOUGH AND CHARACTERISTICS OF BREAD

Experiments were carried out to study the effect of pressure changes when the dough is kneaded with a dough mixer with the possibility of temperature control. In this study, three modes of pressure and rotation speed of a mechanical universal ion-ozone mixer were used: 50, 250 and 500 mbar and 100, 150 and 200 rpm, respectively. The objectives were to understand the effect of pressure and speed of a mechanical universal ion-ozone mixer on dough during kneading in order to optimize dough kneading conditions. The results showed that the cavitation of the dough is proportional to the number of revolutions of the universal ion-ozone dough mixer. Higher pressure and higher stirring speed will shorten the time to reach maximum power, which means that stirring times can be shortened. The specific bread volume, porosity fraction and pore size distribution were analyzed to better understand the effect of high pressure on bread quality.

Multifunctional Properties of Binary Polyrhodanine Manganese Ferrite Nanohybrids-From the Energy Converters to Biological Activity.

The PRHD@MnFe2O4 binary hybrids have shown a potential for applications in the biomedical field. The polymer cover/shell provides sufficient surface protection of magnetic nanoparticles against adverse effects on the biological systems, e.g., it protects against Fenton’s reactions and the generation of highly toxic radicals. The heating ability of the PRHD@MnFe2O4 was measured as a laser optical density (LOD) dependence either for powders as well as nanohybrid dispersions. Dry hybrids exposed to the action of NIR radiation (808 nm) can effectively convert energy into heat that led to the enormous temperature increase ΔT 170 °C (>190 °C). High concentrated colloidal suspensions (5 mg/mL) can generate ΔT of 42 °C (65 °C). Further optimization of the nanohybrids amount and laser parameters provides the possibility of temperature control within a biologically relevant range. Biological interactions of PRHD@MnFe2O4 hybrids were tested using three specific cell lines: macrophages (RAW 264.7), osteosarcoma cells line (UMR-106), and stromal progenitor cells of adipose tissue (ASCs). It was shown that the cell response was strongly dependent on hybrid concentration. Antimicrobial activity of the proposed composites against Escherichia coli and Staphylococcus aureus was confirmed, showing potential in the exploitation of the fabricated materials in this field.

A new luminescent temperature sensor based on palladium(IV) porphyrinate in polystyrene matrix

A composite material based on 15-crown-5-substituted palladium(IV) porphyrinate (PdCl2TCP) and polystyrene is obtained that changes its luminescent properties in the red spectral region at transition from the liquid nitrogen temperature (77 K) to 358 K. Variation of fluorescence and phosphorescence spectra of the material in the course of its heating is analyzed. It is shown that one can determine the sample temperature on the basis of the ratio of intensity of fluorescence and phosphorescence transitions for palladium(IV) porphyrinate in polystyrene. Such a material is a promising luminescent temperature sensor with a very wide range of registered temperatures and a possibility of temperature control in microand even nanosize sample regions due to the fact that temperature determination is based on physical processes occurring in every individual PdCl2TCP molecule.

PROCESS PARAMETERS STUDY OF α-AMYLASE PRODUCTION IN A PACKED-BED BIOREACTOR UNDER SOLID-STATE FERMENTATION WITH POSSIBILITY OF TEMPERATURE MONITORING

Production of α-amylase in a laboratory-scale packed-bed bioreactor by Bacillus sp. KR-8104 under solid-state fermentation (SSF) with possibility of temperature control and monitoring was studied using wheat bran (WB) as a solid substrate. The simultaneous effects of aeration rate, initial substrate moisture, and incubation temperature on α-amylase production were evaluated using response surface methodology (RSM) based on a Box–Behnken design. The optimum conditions for attaining the maximum production of α-amylase were 37°C, 72% (w/w) initial substrate moisture, and 0.15 L/min aeration. The average enzyme activity obtained under the optimized conditions was 473.8 U/g dry fermented substrate. In addition, it was observed that the production of enzyme decreased from the bottom of the bioreactor to the top.

Direct insertion membrane probe for selective introduction of organic compounds into a mass spectrometer

A direct insertion membrane probe for the direct determination of organic compounds in aqueous samples has been designed and built. This device allows the transportation of analyte solution over a sheet membrane via which pervaporation transports compounds directly into the heated ion source of a mass spectrometer. This configuration, together with the possibility of temperature control at the solution/membrane interface, decreases response times (typically <10 s) and memory effects and gives very good sensitivity and low detection limits (down to 10 μg l−1). Optimization of different parameters which affect the performance of the device is reported. High probe temperatures and high flow-rates are generally preferred, giving increased sensitivity. A knowledge of the sample matrix is essential in precise quantitative analysis, because matrix components can change permeation rates and ionization efficiencies. The usefulness of the device in bioreactor monitoring and in environmental analysis is demonstrated.