153 research outputs found
Electrically enhanced drying of white champignons
No full text[EN] Electrohydrodynamic (EHD) drying is a novel non-thermal dewatering technology using electric discharge in air to enhance dehydration of heatsensitive biomaterials. Low energy consumption and high product quality make it attractive for industry. In this study, the mushrooms slices have been dried under sole EHD with 12, 14, and 16 kV DC, and EHD in combination with air cross-flow at 1 m s-1 and different relative humidity (RH) from 30 to 70 %. It was found that drying kinetics was exponential over initial moisture contents from 3.3 to 14.1 g·g-1 (db). The equilibrium moisture content ranged
from 0.15 to 0.1 g g-1 depending on RH. Decrease of RH or air cross-flow significantly improved efficiency of EHD dryingBashkir, I.; Kudra, T.; Martynenko, A. (2018). Electrically enhanced drying of white champignons. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 571-578. https://doi.org/10.4995/IDS2018.2018.7318OCS57157
Sustainability of drying technologies: system analysis
No full textSustainability is a multi-dimensional indicator of the impact of current human activities on future generations. The concept of sustainability could be extended to food drying, reflecting the impact of current drying technologies on energy and resource use, as well as social and food security. The objective of this review is a sustainability assessment of drying, based on the so-called 4E system analysis considering energy, exergy, environmental and economic aspects. For energy analysis, instead of the ambiguous term “efficiency”, it is proposed to use specific energy consumption as a measure of the energy efficiency of drying. For exergy analysis, it is proposed to use specific exergy consumption as a measure of the efficiency of non-renewable resource usage. Both metrics, expressed in kilojoules per kg of extracted water, are good indicators of the sustainability of the drying process and their minimization is the objective of future research in drying technologies. The environmental impact of drying is evaluated as a potential carbon footprint and associated carbon tax rate. Economic analysis characterizes the sustainability of drying technology with the payback period and net present value, which are specific to the dried material. The insight into the effect of drying on the social aspects of sustainability, i.e. malnutrition and food insecurity is also presented. All aspects of sustainability are linked to each, showing how drying processes/technologies can contribute to a more sustainable world.Department of Engineering Faculty of Agriculture Dalhousie UniversityDepartment of Engineering Physics and Mathematics Institute of Chemistry São Paulo State University, São PauloDepartment of Engineering Physics and Mathematics Institute of Chemistry São Paulo State University, São Paul
COOPERATIVE EFFECTS IN OPTICAL AND ESR SPECTROSCOPY OF NITROGEN ATOMS ISOLATED BY SOLIDIFICATED HELIUM
No full text1. E.B. Gordon, V.V. Khmelenko, A.A. Pelmenev, E.A. Popov and O.P. Pugachev, Chem. Phys. Lett. 155(3), 301-304 (1989). 2. R.E. Boltnev, E.B. Gordon, V.V. Khmelenko, A.A. Pelmenev, I.N. Kusliniskaya, M.V. Martynenko, E.A. Popov and A.V. Shestakov, Chem. Phys. 189(2), 367-382 (1994). 3. R.E. Boltnev, E.B. Gordon, V.V. Khmelenko, M.B. Martynenko, A.A. Pelmenev, E.A. Popov and A.F. Shestakov, J. Chim. Phys. 92(2), 362-383 (1995).Author Institution: Institute for Energy Problems of Chemical Physics (branch)The heavy guest particles embedded to superfluid helium can cause its . The so-called Impurity Helium Solid Phase (IHSP) being stable then up T = 7K shows the regular arrangement of the impurities with their reliable isolation by helium atoms. The feasibility of previously excited species capture to IHSP may be achieved. So metastable N(D) atoms display extremely long-lived, more than s, luminescence. Their radiative decay turns out to be caused solely by excimer-like state formation with accidentally neighbouring heavy . That was proved for N(D)-Rg pairs (Rg = Ne, Ar, Kr, Xe) by both spectra shapes and emission lifetimes observed. For N(D)- state the comparison of atomic and rovibronic spectra evidences their excimer nature as . The distances between neighbour N atoms in IHSP, 1 mm, are small enough for cooperative bulk magnetic effects appearances. ESR experiments with N(S) atoms show the effects of either magnetic alignment or spin-exchange narrowing
LOW TEMPERATURE INTRAMOLECULAR ENERGY TRANSFER IN GAS PHASE EVIDENCED BY LUMINESCENCE OF , AND CN.
No full text1. E.B. Gordon, A.A.Pelmenev, O.F. Pugachev and V.V.Khmelenko, Chem. Phys. 61(1,2), 35-41, 1981. 2. E.B. Gordon, M.V. Martynenko, A.A. Pelmenev, O.F. Pugachev and V.V. Khmelenko, Khimicheskay Fizika, 13(3), 15-28, 1994, (in Russian).Author Institution: Institute for Energy Problems of Chemical Physics, 1142432, Chernogolovka, Moscow Region, Russia.Gas phase luminescence spectra of N_{2} (1^{+}-system), (N^{+}}_{2} (1^{+}-system), and CN (Red system) in the temperature range 180K - 20K have been studied in the frame of original experimental approach [1] consisting in injection of helium gas jet containing the exposed to HF discharge admixtures under investigation into the cryostat with superfluid helium . At low temperatures together with strong suppression of rotational structure the dramatic changes in the vibronic bands intensity (some bands almost completely disappear) are observed [2]. For all vibrational levels from which emission is temperature sensitive there are quasiresonant vibrational levels belonging to another electronic states of the same species. So the effect has been explained by effective energy transfer between the electronic states induced by collisions with cold helium atoms . The emission bands intensity is determined by mutual disposition of the interacting levels. Its decrease or increase depend on whether exothermic or endothermic, respectively, transition from emitting level to neighboring one. Observed phenomena provide new opportunities for accurate testing the mutual disposition of different electronic states in diatomics as well as for study of intersystem collisional induced processes
Electrohydrodynamic (EHD) drying: fundamentals and applications
No full text[EN] Following background to the phenomenon of electrohydrodynamics with concise review of basic features like shorter drying time, lower energy consumption and better product quality, the selected key factors affecting EHD drying are examined. These include the geometry of discharge electrodes, effects of air humidity on drying rate, depression of material temperature, and cooling effect of ionic wind. Examples are given for: (i) prototype EHD dryers of multi-belt types, and (ii) pilot-scale multi-belt EHD dryer in vertical arrangement that can be aggregated into one unit of higher capacity, and vertical cylindrical EHD dryer with vibrated shelves.Martynenko, A.; Kudra, T. (2018). Electrohydrodynamic (EHD) drying: fundamentals and applications. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 73-80. https://doi.org/10.4995/IDS2018.2018.7932OCS738
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