polarization coefficient
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2021 ◽  
Vol 2094 (5) ◽  
pp. 052007
Author(s):  
P V Belolipetskii ◽  
V S Potylitsyn ◽  
G Y Shajdurov ◽  
V V Romanov

Abstract The article discusses a numerical model for assessing the depth for the passive method of induced polarization based on previously obtained experimental data at the Samson field (Republic of Khakassia). The model is based on the mathematical model of Komarov, who derived equations for the anomalous polarizability of a sphere observed on the Earth’s day surface, the proposed model for estimating the depth of the anomaly depends on the size of the proposed field and the induced polarization coefficient observed on the surface. In the course of the numerical assessment, it was shown that there is a convergence of data from field observations, exploration drilling and mathematical modeling.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Natalia Matvienko ◽  
Alexander Koziy ◽  
Alexander Didenko ◽  
Issak Sherman

Optimization of the process of sterlet feeding in recirculating aquaculture systems allows improving the physiological status and pre-spawning performance of fish. The addition of the organophosphorus compound Catosal based on butaphosphamide to pre-spawning feeds leads to an increase in glycogenogenesis in hepatocytes, which manifests itself as a decrease in cell and nucleus area (by 1.20 and 1.31 times), stabilization of nucleoplasmic ratios (0.28-0.25). Butaphosphamide also causes an increase in hemoglobin and serum protein concentrations by 6.1 g/L and 3.92 g/L, respectively. An increase in the live weight of sterlet by 98.0 g and an absolute increase in weight by 1.96 g associated with an improvement in hematological parameters was observed. The excess phosphorus in the form of butaphospham, which is not involved in the process of glycogenesis, is transported to gonads and stimulates vitellogenesis. The acceleration of oocyte development is determined upon reaching the optimal polarization coefficient (0.05≤Pc≤0.10, category II).


Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1297
Author(s):  
Morteza Aliabadi ◽  
Hassan Ghorashi ◽  
Shamim Shokri Motlagh ◽  
Seyedeh Fatemeh Nabavi ◽  
Seyed Arash Pakzad ◽  
...  

A multi-staged direct contact membrane distillation (MDCMD) system is designed considering a novel bispacer configuration in the present study. The proposed bispacer DCMD, which has not been addressed in the literature to best of our knowledge, is considered with two purposes, including increasing mechanical stability and turbulence. As increasing turbulence leads to increasing Nusselt number, the bispacer MDCMD provides higher permeate flux. An analytical approach is considered using energy and mass balance correlation. The effect of bispacer and feed operating conditions, including feed temperature, feed flow rate, feed salinity, and the number of stages on permeate flux and salt rejection of the developed MDCMD, are examined both analytically and experimentally. The performance and sustainability of the developed system were investigated by analyzing the parameters, including thermal efficiency (η), gained output ratio (GOR), and temperature polarization coefficient (TPC).


2021 ◽  
Vol 11 (5) ◽  
pp. 2309
Author(s):  
Arpita Koley ◽  
Santanu K. Maiti ◽  
Judith Helena Ojeda Silva ◽  
David Laroze

In this work, we put forward a prescription of achieving spin selective electron transfer by means of light irradiation through a tight-binding (TB) magnetic chain whose site energies are modulated in the form of well known Aubry–Andre–Harper (AAH) model. The interaction of itinerant electrons with local magnetic moments in the magnetic system provides a misalignment between up and down spin channels which leads to a finite spin polarization (SP) upon locating the Fermi energy in a suitable energy zone. Both the energy channels are significantly affected by the irradiation which is directly reflected in degree of spin polarization as well as in its phase. We include the irradiation effect through Floquet ansatz and compute spin polarization coefficient by evaluating transmission probabilities using Green’s function prescription. Our analysis can be utilized to investigate spin dependent transport phenomena in any driven magnetic system with quasiperiodic modulations.


2021 ◽  
Vol 26 (1) ◽  
pp. 64-73
Author(s):  
A.G. Efimov ◽  
◽  
S.A. Korneev ◽  
V.S. Matveev ◽  
V.V. Chistyukhin ◽  
...  

In designing the receiving-transmitting active phased antenna array (APAA) an important problem is an achievement of the level of maximum outcome between the receiving and transmitting channels. In the work, the concept of building multi-beam receiving-transmitting antenna systems based on APAA has been considered. The criteria for selecting the type of emitter for an S-band antenna with the specified parameters have been presented. It has been shown that the use of a turnstile emitter based on the printing technology can reduce the complexity of manufacturing without compromising the technical parameters. In accordance with the requirements for volume of the tasks of APAA being designed the optimal geometric and electric characteristics of the turnstile radiator have been calculated. In designing the radiating apertures of the multi-element APAA the specifics of the dependence of their electric characteristics on the inter-element distance has been taken into consideration. To increase the circular polarization coefficient of the apertures being designed, the method of tearing apart of the radiator with further compensation of the obtained phase using the phase rotators APAA has been implemented. The estimates of the energy characteristics of the multi-element antennas with a given scanning sector for various inter-element distances have been given. To ensure the separation of the receiving and transmitting antennas the recommendations have been presented.


Entropy ◽  
2020 ◽  
Vol 22 (9) ◽  
pp. 1021
Author(s):  
Kornelia M. Batko ◽  
Andrzej Ślęzak

The results of experimental studies of volume osmotic fluxes (Jvkr) and fluxes of dissolved substances (Jkr) in a system containing a synthetic Nephrophan® membrane (Orwo VEB Filmfabrik, Wolfen, Germany) set in a horizontal plane are presented. The membrane separated water and aqueous HCl or ammonia solutions or aqueous ammonia and HCl solutions. It was found that for the homogeneity conditions of the solutions Jvk and Jk depend only on the concentration and composition of the solutions. For concentration polarization conditions (where concentration boundary layers are created on both sides), Jvkr and Jkr depend on both the concentration and composition of the solutions and the configuration of the membrane system. The obtained results of the Jvk and Jk flux studies were used to assess the global production of entropy for the conditions of homogeneity of solutions (ΦSk), while Jvkr and Jkr—to assess the global production of entropy for concentration polarization conditions (ΦSkr). In addition, the diffusion-convective effects and the convection effect in the global source of entropy were calculated. The concentration polarization coefficient ζir was related to modified concentration Rayleigh number, e.g., the parameter controlling the transition from non-convective (diffusive) to convective state. This number acts as a switch between two states of the concentration field: convective (with a higher entropy source value) and non-convective (with a lower entropy source value). The operation of this switch indicates the regulatory role of earthly gravity in relation to membrane transport.


Author(s):  
Robert Krysko ◽  
Abdulaziz M. Alasiri ◽  
Umar Alqsair ◽  
Sertac Cosman ◽  
Alparslan Oztekin

Abstract Computational fluid dynamic simulations are conducted to compare the performance of three proposed VMD module designs. Key parameters, including concentration polarization coefficient (CPC), temperature polarization coefficient (TPC), mass flux, and module pressure drop, are evaluated to analyze flux performance and membrane wetting implications. The CFD simulations are conducted on a three-dimensional domain for each design with representative membrane properties. The Reynolds numbers evaluated are 500 and 1500. Contour plots are provided to gain insight into the flow-field characteristics. Stream-wise profiles and average values are provided as a means to compare the design performance. The results indicate that adding either net-type spacers or membrane corrugation to the feed channel provides performance enhancement over an empty channel design. It is found that both the net-type spacer concept and the corrugated membrane offer better flux performance over the baseline design (49%–60% for the net-type spacers and 62%–67% flux enhancement for the corrugated membrane), reduced concentration polarization coefficient (51% for the Re = 500 case and 45% for the Re = 1500 case for spacers and 58% for the Re = 500 case and 49% for the Re = 1500 case for corrugation), increased TPC (2%–3% higher), and increased wall shear stress over the baseline design. The most significant finding is that the corrugated membrane design accomplishes the listed performance improvement while yielding five times less pressure drop increase than the net-type spacer design.


2019 ◽  
Vol 1 (3) ◽  
pp. 67-73
Author(s):  
T. P. Ospelnikova ◽  
O. V. Morozova ◽  
S. A. Andreeva ◽  
E. I. Isaeva ◽  
L. V. Kolodyazhnaya ◽  
...  

Aim. Analysis of inflammation biomarkers using reverse transcription with real time PCR (RT-PCR-RT) and multiplex immunofluorescent analysis xMAP with magnetic beads for the influenza infection. Materials and methods. Analysis of nasopharyngeal swabs, lymphocytes and blood sera of 10 patients with influenza and 10 donors was performed during the first 2 days of the disease by means of RT-PCR-RT and xMAP using the kit «37-plex» (BioRad). Results.The influenza virus A was revealed in 4 samples, the influenza virus B — in 6 swabs without mixed infections with other respiratory viruses. Analysis of the interferons (IFN) showed IFNα gene expression activation in patients’ lymphocytes but both the detection rate and the concentrations of IFNβ, IFNγ and IFNλ RNA were similar for patients and healthy donors. Among 37 inflammation biomarkers the concentrations of 7 proteins were enhanced including IFNα2, cytokines of TNF family (APRIL and BAFF), their soluble receptors sTNF-R1 and sTNF-R2, protein osteopontin and IL10. The concentrations of the complex of glycoprotein gp130 with the soluble receptor IL6 gp130/sIL-6Rβ and the matrix metalloprotease ММР-1 were reduced in patients’ sera. The polarization coefficient PI=[IL10]/[IFNγ]=0.53 for influenza samples suggested Th1 immune response. Conclusion. At the early stage of the influenza infection IFNα gene expression activation along with the induction of TNF family cytokines (APRIL and BAFF), their receptors (sTNF-R1 and sTNF-R2) and osteopontin as well as the inhibition of the complex gp130/sIL-6Rβ and metalloprotease ММР-1 were shown. Th1 immune response regulated by IL10 resulted in the recovery of the patients without complications.


2017 ◽  
Vol 34 (1) ◽  
Author(s):  
Rakesh Baghel ◽  
Sushant Upadhyaya ◽  
Kailash Singh ◽  
Satyendra P. Chaurasia ◽  
Akhilendra B. Gupta ◽  
...  

AbstractThe main aim of this article is to provide a state-of-the-art review of the experimental studies on vacuum membrane distillation (VMD) process. An introduction to the history of VMD is carried out along with the other membrane distillation configurations. Recent developments in process, characterization of membrane, module design, transport phenomena, and effect of operating parameters on permeate flux are discussed for VMD in detail. Several heat and mass transfer correlations obtained by various researchers for different VMD modules have been discussed. The impact of membrane fouling with its control in VMD is discussed in detail. In this paper, temperature polarization coefficient and concentration polarization coefficient are elaborated in detail. Integration of VMD with other membrane separation processes/industrial processes have been explained to improve the performance of the system and make it more energy efficient. A critical evaluation of the VMD literature is incorporated throughout this review.


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