scholarly journals Influence of temperature effects associated with the dissociation/recombination reaction of water molecules and Joule heating of the solution on the stationary transport of salt ions in the diffusion layer

2018 ◽  
Vol 15 (4) ◽  
pp. 67-84 ◽  
Author(s):  
A.V. Kovalenko ◽  
◽  
M.K. Urtenov ◽  
N.O. Chubyr ◽  
A.M. Uzdenova ◽  
...  
Keyword(s):  
Joule Heating ◽  
Diffusion Layer ◽  
Temperature Effects ◽  
Water Molecules ◽  
Recombination Reaction ◽  
Influence Of Temperature ◽  
Salt Ions

scholarly journals Modeling and numerical analysis of the effect of dissociation/recombination of water molecules on the transport of salt ions in diffusion layer

2019 ◽  
Vol 19 (3) ◽  
pp. 268-280
Author(s):  
N. O. Chubyr ◽  
A. V. Kovalenko ◽  
M. Kh. Urtenov ◽  
A. I. Sukhinov ◽  
V. A. Gudza
Keyword(s):  
Mathematical Model ◽  
Numerical Analysis ◽  
Boundary Value Problem ◽  
Joule Heating ◽  
Diffusion Layer ◽  
Temperature Effects ◽  
Boundary Value ◽  
Water Molecules ◽  
Recombination Reaction ◽  
Salt Ions

Introduction. The paper presents a theoretical study on binary salt ion transport considering the water dissociation/recombination reaction. The work objectives are as follows: to build a mathematical model; to develop an algorithm for the numerical solution to the boundary value problem corresponding to the mathematical model; to work out the similarity theory including the transition to a dimensionless form using characteristic quantities; to determine a physical meaning of trivial similarity criteria; to find nontrivial similarity criteria; to build and analyze the volt-ampere characteristic (VAC).Materials and Methods. The theoretical study and numerical analysis of the transport of binary salt ions consider the dissociation/recombination reaction of water. In this case, the heat transfer equation and the mathematical model of electrodiffusion of four types of ions simultaneously (two salt ions, as well as ????+ and ????????−ions) in the diffusion layer of electromembrane systems with a perfectly selective membrane are used. For the first-order differential equations, a singularly perturbed boundary-value problem is set. In the equation for the electric field, the right side is independent of the intensity. In the numerical solution to the digitized system of equations by the Newton-Kantorovich method, this causes the stability of the method. In this regard, the boundary-value problem is reduced for numerical solution: a transition to a system of the second-order equations is provided, and the missing boundary conditions for the electric field strength are calculated.Research Results. A new mathematical model, a numerical algorithm to solve a boundary value problem, and software are developed. A numerical analysis is carried out, and fundamental laws of the transport of salt ions are determined considering the dissociation/recombination reaction of water molecules, temperature effects, and Joule heating. The VAC is built and analyzed.Discussion and Conclusions. The transport of binary salt ions through a diffusion layer near a cation exchange membrane is considered. A mathematical model of this process is proposed. It takes into account the temperature effects due to dissociation/recombination reactions of water molecules and Joule heating in a solution. The basic laws of the transport of salt ions are established considering the dissociation/recombination reaction of water molecules and temperature effects. The temperature effects of the dissociation/recombination reaction and the Joule heating in the electroneutrality region (ENR) are almost imperceptible (with the exception of the recombination region, RR). The Joule heating in the space-charge region (SCR) is by two orders of magnitude larger than the cooling effect of the water dissociation reaction. Upon recombination, approximately the same heat is released in the RR as during Joule heating in the expanded SCR. However, due to the small size of the RR, the effect of this heat is imperceptible. Therefore, we can assume that there is only one heat source at the interface in the SCR, which, due to its noticeable size, causes a significant increase in temperature in the entire diffusion layer. It follows that the emergence and development of gravitational convection is possible. General conclusions, following from the results obtained, open up the possibility of intensifying the process of transport of salt ions in the electrodialysis machines.

scholarly journals Theoretical Analysis of the Stationary Transport of 1:1 Salt Ions in a Cross-Section of a Desalination Channel, Taking into Account the Non-Catalytic Dissociation/Recombination Reaction of Water Molecules

Membranes ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 342
Author(s):  
Makhamet Urtenov ◽  
Vitaly Gudza ◽  
Natalia Chubyr ◽  
Inna Shkorkina
Keyword(s):  
Ion Transport ◽  
Space Charge ◽  
Cross Section ◽  
Mutual Influence ◽  
Double Electric Layer ◽  
Limiting Current ◽  
Water Molecules ◽  
Recombination Reaction ◽  
Salt Ions ◽  
The One

In electromembrane systems, the theoretical study of salt ion transport usually uses mathematical models of salt ion transport in the depleted diffusion layer of ion-exchange membranes. This study uses a one-dimensional mathematical model of salt ion transport in a cross-section of a desalination channel formed by anion-exchange and cation-exchange membranes, taking into account an effect of a dissociation/recombination reaction of water molecules. The reaction on the one hand leads to an overlimiting mass transfer due to the effect of exaltation of the limiting current. On the other hand, an appearance of new electric charge carriers (hydrogen and hydroxyl ions) can reduce the space charge that occurs in membranes and suppress an electroconvective mechanism of overlimiting transport. Thus, there is a problem of studying these phenomena together, taking into account their mutual influence, and this article is devoted to the solution of this problem. Theoretically, using a method of mathematical modeling and numerical research, main regularities are established; in particular, it is shown that the dissociation/recombination reaction of water molecules does not lead to the destruction of the double electric layer at the membranes, but also creates a new double electric layer in the middle of the desalination channel. Thus, the space charge and the dissociation/recombination reaction significantly affect each other and simultaneously the transport of salt ions.

TEMPERATURE EFFECTS ON THE ASH COLOUR OF FOREST LITTER / TEMPERATŪROS ĮTAKA MIŠKO PAKLOTĖS PELENŲ SPALVAI

2011 ◽  
Vol 3 (5) ◽  
pp. 18-23
Author(s):  
Jolita Dūdaitė ◽  
Edita Baltrėnaitė ◽  
Paulo Pereira ◽  
Xavier Úbeda
Keyword(s):  
Leaf Litter ◽  
Temperature Effects ◽  
Mixed Forest ◽  
Forest Litter ◽  
Acer Platanoides ◽  
Informative Feature ◽  
Influence Of Temperature ◽  
Surrounding Environment ◽  
Colour Chart

Research was carried out to identify the influence of temperature (150, 250, 350, 450, 550ºC) on the ash colour of Acer platanoides L. leaf litter and Pinus sylvestris L. needle litter samples collected from deciduous coniferous mixed forest in Lithuania (54º43‘ N 25º19‘ E) in April 2010. To achieve the objective, a laboratory experiment was conducted to determine ash samples using the Munsell Colour Chart. The analysis of colours has demonstrated that considering all litter samples, an increase in the temperature of litter heating was found to increase ash colour values (r = 0.92; p = 0.01). All the samples (n = 50) of both litter species were divided into categories 2.5Y (5 samples), 7.5YR (10 samples) and 10YR (35 samples). The total black Munsell colour was observed at a temperature of 350ºC for both litter species. Needle ash started turning bright at a temperature of 550ºC while the complete consumption of leaf litter was visible at a temperature of 450ºC. We conclude that the Munsell Colour Chart used for predicting the colour of ash is an informative feature to have the primary classification of ash. It is imperative to analyse the colour of the litter ash of the selected tree species in order to quickly and easily assess and predict their possible impact on the surrounding environment. Santrauka Tyrimas atliktas siekiant nustatyti temperatūros įtaką (150, 250, 350, 450, 550 ºC) paprastosios pušies spyglių ir paprastojo klevo lapų, surinktų iš lapuočių ir spygliuočių mišraus miško Lietuvoje (54° 43 „N 25° 19 ‚E) 2010-ųjų balandį, pelenų spalvai. Laboratorijoje Munsell spalvų sistema buvo naudojama, norint nustatyti pelenų spalvos reikšmes. Tyrimas parodė, kad didinant degimo temperatūrą visų pelenų spalvų vertės atitinkamai didėjo (r = 0,92, p = 0,01). Pagal spalvų skalę visus mėginius (50) galima suskirstyti į kategorijas: 2.5Y (5 mėginiai), 7.5YR (10 mėginių) ir 10YR (35 mėginiai). Juoda spalva buvo stebima abiejų rūšių pelenuose, kurie buvo deginami 350 ºC temperatūroje. Spyglių pelenai tapo šviesūs esant 550 ºC temperatūrai, o šviesėjantys lapų pelenai pastebėti 450 ºC temperatūroje. Galime teigti, kad Munsell spalvų sistemos naudojimas pelenų spalvai nustatyti yra informatyvus pirminės pelenų klasifikacijos rodiklis.

scholarly journals The Influence of Temperature on Metabolisms of Phosphorus Accumulating Organisms in Biological Wastewater Treatment Plants in the Presence of Cu(II) Toxicity

2019 ◽  
Vol 9 (6) ◽  
pp. 1126 ◽  
Author(s):  
Chen-Chiang Chou ◽  
Chih-Chi Yang ◽  
Meng-Shan Lu ◽  
Li-Yuan Hu ◽  
Ku-Fan Chen ◽  
...  
Keyword(s):  
Temperature Effects ◽  
Shock Loading ◽  
Wastewater Treatment Plants ◽  
Glycogen Synthesis ◽  
Phosphorus Uptake ◽  
Phosphorus Release ◽  
Biological Wastewater Treatment ◽  
Influence Of Temperature ◽  
Toxic Environment ◽  
Influence Of Temperature On

The purpose of this study was to study how temperature variation affects the tolerance of phosphorus accumulating organisms (PAOs) in a toxic environment. To exclude the interference of glycogen accumulating organisms (GAOs), shock loading experiments were conducted to study the effect of Cu(II) toxicity on the metabolisms of PAOs in 10, 20, and 30 °C conditions. The experimental data showed that the temperature effects on aerobic phosphorus uptake, PHA degradation, and glycogen synthesis were remarkable in the presence of Cu(II). Nevertheless, insignificant effects on anaerobic phosphorus release and PHA synthesis were found. The largest inhibition of PAO metabolism occurred in the low temperature case (10 °C). This study also experimentally demonstrated the loss of PAO metabolic ability in the subsequent aerobic stage, after the anaerobic stage. The presence of Cu(II) toxicity mainly resulted from the inhibition of biochemical reactions in the aerobic stage, and it was irrelevant to the inhibition of previous anaerobic metabolisms.

Influence of temperature effects on the domain structure of iron-nickel films

1972 ◽  
Vol 15 (6) ◽  
pp. 859-862
Author(s):  
L. I. Chernysheva ◽  
G. I. Belik ◽  
N. I. Sivkov ◽  
N. I. Savenko ◽  
D. A. Laptei
Keyword(s):  
Domain Structure ◽  
Temperature Effects ◽  
Influence Of Temperature ◽  
Nickel Films ◽  
Iron Nickel

On the instability of localized EM pulses in nonlinear electrodynamics with account of temperature effects

2021 ◽  
Vol 35 (10) ◽  
pp. 2150176
Author(s):  
Mikhail B. Belonenko ◽  
Natalia N. Konobeeva ◽  
Alexander V. Zhukov
Keyword(s):  
Electromagnetic Field ◽  
Pair Production ◽  
Temperature Effects ◽  
Electromagnetic Pulse ◽  
Maxwell’S Equations ◽  
Maxwell's Equations ◽  
Nonlinear Electrodynamics ◽  
Influence Of Temperature ◽  
Schwinger Mechanism

Based on Maxwell’s equations, we study the development of electromagnetic pulse instability in nonlinear electrodynamics beyond approximation of slowly varying amplitudes and phases. The action was chosen from the Heisenberg–Euler Lagrangian based on the invariants of the electromagnetic field. We analyze the scenario for the evolution of instability, which turns out to be consistent with the earlier conclusion done within the approximation of slowly varying amplitudes and phases. In this study, we take into account the influence of temperature. The rate of pair production under the Schwinger mechanism is estimated.

scholarly journals Temperature effects on Trichogramma pretiosum Riley and Trichogrammatoidea annulata De Santis

2003 ◽  
Vol 46 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Arlei Maceda ◽  
Celso L Hohmann ◽  
Honório R. dos Santos
Keyword(s):  
Temperature Effects ◽  
Entire Temperature Range ◽  
Temperature Threshold ◽  
Trichogramma Pretiosum ◽  
Degree Days ◽  
Parasitoid Species ◽  
Influence Of Temperature ◽  
Anagasta Kuehniella ◽  
Influence Of Temperature On ◽  
Lepidoptera Pyralidae

The influence of temperature on lifetime attributes of Trichogramma pretiosum Riley and Trichogrammatoidea annulata De Santis (Hymenoptera: Trichogrammatidae) was evaluated at four constant temperatures (15, 20, 25, and 30º C), RH 70 ± 10%, photophase 14 h. Anagasta kuehniella (Lepidoptera: Pyralidae) eggs were used as hosts. Developmental times of both parasitoid species were similar when exposed to 20, 25, or 30º C. T. annulata, however, developed slightly faster than T. pretiosum at 15º C. Emergence rates of both species were above 89%. The temperature threshold for T. pretiosum and T. annulata was 11º C and the number of degree-days required for their development was 126.9 and 122.3, respectively. Parasitization was maximal at 25º C. T. annulata, however, parasitized significantly more hosts than T. pretiosum in the entire temperature range. Temperature had no effect in brood size.T. annulata progeny consisted predominantly of males, except at 15º C, whereas in T.pretiosumitconsisted predominantly of females, except at 30º C. Parental females lived longer than males.

SHELLS AND SUPERSHELLS IN METAL CLUSTERS

1993 ◽  
Vol 07 (04) ◽  
pp. 197-216 ◽  
Author(s):  
O. GENZKEN
Keyword(s):  
Temperature Effects ◽  
Body Problem ◽  
Metal Clusters ◽  
Local Density ◽  
Density Approximation ◽  
Jellium Model ◽  
Many Body ◽  
Influence Of Temperature ◽  
Valence Electrons ◽  
The Many

We analyze the shell and supershell structure of valence electrons in large metal clusters. For this purpose we use the spherical jellium model for the ions, treat the many-body problem of the interacting valence electrons selfconsistently in local-density approximation and solve numerically the Kohn-Sham equations for up to N ~ 6000 electrons. We investigate the influence of temperature effects on the shell structure and compare our results to experimental data and other calculations performed with phenomenological Woods–Saxon potentials.

Sign in / Sign up

Export Citation Format

Share Document