Antifungal Effect of Allium tuberosum,Cinnamomum cassia,and Pogostemon cablin Essential Oils and Their Components Against Population of Aspergillus Species

Antifungal activity of Allium tuberosum (AT), Cinnamomum cassia (CC), and Pogostemon cablin (Patchouli, P) essential oils against Aspergillus flavus strains 3.2758 and 3.4408 and Aspergillus oryzae was tested at 2 water activity levels (a_w: 0.95 and 0.98). Main components of tested essential oils were: allyl trisulfide 40.05% (AT), cinnamaldehyde 87.23% (CC), and patchouli alcohol 44.52% (P). The minimal inhibitory concentration of the plant essential oils against A. flavus strains 3.2758 and 3.4408 and A. oryzae was 250 ppm (A. tuberosum and C. cassia), whereas Patchouli essential oil inhibited fungi at concentration > 1500 ppm. The essential oils exhibited suppression effect on colony growth at all concentrations (100, 175, and 250 ppm for A. tuberosum; 25, 50, and 75 for C. cassia; 100, 250, and 500 for P. cablin essential oil). Results of the study represent a solution for possible application of essential oil of C. cassia in different food systems due to its strong inhibitory effect against tested Aspergillus species. In real food system (table grapes), C. cassia essential oil exhibited stronger antifungal activity compared to cinnamaldehyde.     

Size-Resolved Penetration Through High-Efficiency Filter Media Typically Used for Aerosol Sampling

We have developed a new, fully controlled filter testing device and have used it to measure size-resolved penetration through a typically used filtration media for (but not only) atmospheric aerosol sampling. Twenty membrane and fiber filter pieces (mixed cellulose ester filters, polytetrafluoroethylene filters, quartz fiber filters, glass fiber filters, and polycarbonate filters) of various manufacturers and filter codes were examined. High variability in the penetration curve shapes, most penetrating particle size (MPPS) (from 20 nm to 90 nm) and penetration maxima (from 0.001% to almost 100%) has been found. The dependence of pressure drop on face velocity generally agrees with theory, the comparison of penetration at various face velocities proved the theoretical equations being able to determine MPPS only partially correctly. Although the variability within an individual filter of the same code is not negligible, it is small compared to the differences between the various filter types. The results not only differed from the information provided by the manufacturers, but in many cases also provided information otherwise unavailable, although affecting the sampling and also the ability of comparison with theory. To have enough information for the proper choice of the filter for a given purpose, it would be necessary to have not only total penetration given from the DOP standard measurement, but the MPPS, penetration maximum value and pressure drop as well.

Copyright 2015 American Association for Aerosol Research     

Metabolic changes in the rat brain after a photochemical lesion treated by stem cell transplantation assessed by 1H MRS

Object  Metabolite changes in an experimental lesion in the rat cortex and in the contralateral hemisphere after the intravenous administration of mesenchymal stem cells (MSCs) were assessed by proton MR spectroscopy to verify the impact of the cell treatment on the brain tissue. Materials and methods  Wistar rats with a photochemical cortical lesion and transplanted MSCs or sham transplanted rats were examined. Proton spectra were obtained from the lesion and from the contralateral cortex. Results  Magnetic resonance spectroscopy revealed a gradual recovery of the damaged tissue; however, we found no significant differences in metabolite concentrations in the lesioned hemisphere between treated and untreated animals. Higher concentrations of glutamate and N-acetyl aspartate were found in the contralateral hemisphere in cell-treated animals compared to untreated ones. Lesioned animals showed neurogenesis in the contralateral hemisphere; the number of newly generated cells in stem cell-treated animals was 50% higher than those observed in untreated animals. Conclusion  No direct impact of cell transplantation was observed in the lesion. However, changes in the contralateral hemisphere suggest that the transplanted MSCs might stimulate repair processes and plasticity resulting in the generation of newborn cells, which might enable the faster adoption of the damaged tissue’s function by healthy tissue.     

Impact of initial conditions on the initiation of ferroresonance

The impact of initial conditions on the initiation of ferroresonance is investigated. The investigation is carried out by simulating the behaviour of the model of a 275 kV electromagnetic voltage transformer circuit for a range of practical values of other system parameters. The initial conditions are varied within a practically possible range of initial values of transformer voltage and transformer flux linkage. Additionally, the initiation of ferroresonance is investigated by varying the values of phase angle of voltage source and values of shunt capacitance for the initial values that could appear in two basic cases of ferroresonance initiation.     

Modelling of thermal processes at waste incineration

The article describes the possibilities of optimization of combustion processes at waste incineration, which require a specific approach in comparison with conventional fuels. The main cause is an instability of thermo-chemical properties of majority of waste. The work defines and evaluates criteria, which are critical for the waste incineration process. The numerical model “Combustion temperature” for optimization of thermal work of the waste incinerator was designed for support of implementation of other measures aimed at increasing the process energy efficiency, and it was verified in practice in real waste incineration plant.     

Reversed anisotropy of grain boundary properties and its effect on grain boundary engineering

Data on anisotropy of grain boundary properties are frequently published. In some cases, when they show the reverse course of structural dependence than is expected, they can seem confusing. Examples of this “reversed anisotropy” found for grain boundary segregation, diffusion and migration are presented. We demonstrate that the reversed anisotropy of grain boundary properties is caused by the compensation effect. This can have serious consequences for grain boundary engineering. It is also suggested that grain boundaries can be classified specifically and generally solely on the basis of well-defined thermodynamic parameters.     

Texture and microstructure evolution in ultrafine-grained AZ31 processed by EX-ECAP

Extruded AZ31 alloy was processed by equal channel angular pressing (ECAP) up to 12 passes at 180 °C following route B_c, i.e. rotating the sample 90° between individual passes. Microstructure evolution was investigated using EBSD and TEM, as a function of strain imposed by ECAP. The first ECAP pass resulted in the formation of a new texture component which relates to the bimodal grain structure observed in this specimen. The grains larger than 10 μm show the orientation changes corresponding to the ECAP shear, which is characterised by the rotation of the basal poles by approximately 40° from the initial orientation. The fine grains with the average size of 1 μm maintain the initial orientation. The character of the bimodal grain structure and the distinct texture components between large and small grains remained unchanged up to 4 ECAP passes. Further ECAP pressing to 8 and 12 passes leads to a grain refinement through the whole sample volume and the orientation changes of all grains corresponding to the ECAP shear.     

Enzymatic hydrolysis of protein isolate from hull-less pumpkin oil cake: Application of response surface methodology

Enzymatic hydrolysis of protein isolate from hull-less pumpkin (Cucurbita pepo L.) oil cake was studied by response surface methodology, using a central-composite experimental design. The hydrolysis was carried out with an acid protease, at temperature of 30 °C and pH 3.00. Second-order polynomial model was proposed with regard to of effect of time, enzyme and NaCl concentration. The mathematical model showed good fit with the experimental data, since the R² of 0.946 indicated that 94.6% of the variability within the range of values studied could be explained by the model. A hydrolysis time of 32.5 h, enzyme concentration of 0.137% (v/v) and NaCl concentration of 0.84% (w/v) were found to be the optimal conditions to achieve the highest value of degree of hydrolysis (DH).     

Finite element simulations of the loading and deformation of plywood seat shells

Modern 3D modelling software reduces the need for a large number of prototypes, means fewer product-development cycles and lower costs (time/cost), as well as improving the quality of furniture designs. However, the mechanical testing of final products is still required in order to confirm the simulation results. In this study the theoretical behaviors of different plywood seating shells (using the SolidWorks^® FEM simulation software) were compared with the real results obtained using tests to measure the deformation of the backrest. The deviations of the actual deformation from the simulation were significant for the different shells and increased with loading above the elastic deformation limit of the material. It was concluded that the SolidWorks^® simulation software could be effectively used in the calculation of the component displacements, strains, and stresses of seat designs subject to internal and external loads.