scholarly journals Magnetic Field Effect on Water Surface Tension in Aspect of Glass and Mica Wettability

2020 ◽  
Vol 4 (3) ◽  
pp. 37
Author(s):  
Aleksandra Szcześ ◽  
Emil Chibowski ◽  
Emilia Rzeźnik
Keyword(s):  
Magnetic Field ◽  
Surface Tension ◽  
Free Energy ◽  
Surface Free Energy ◽  
Magnetic Field Effect ◽  
Contact Angles ◽  
Acid Base ◽  
Water Contact ◽  
The Difference ◽  
The Magnetic Field

It was reported in many papers that the magnetic field (MF) affects properties of water, and, among others, its surface tension. Thus, it should be reflected in changes of the wetting contact angle of a water droplet deposited on the solid surface. In this study, the water contact angles were measured on the glass and mica surface. The water was first exposed to the static magnetic field (MF) (15 mT or 0.27 T) for 1, 5, and 10 min under dynamic conditions. Then applying the van Oss et al. approach (LWAB), it was found that the MF effect is reflected in the changes of the calculated acid-base components of the solids, especially the electron donor parameter. However, the total surface free energy of the solids remained practically unchanged. Moreover, the apparent surface free energy of the solids calculated from the water contact angle hysteresis (CAH), i.e., the difference between the advancing and receding contact angles, changes in the same way as the electron donor parameter does. Since the solid surfaces were not magnetically treated, the acid-base components, which are mainly results from hydrogen bonding interactions, may be indirect evidence of the water structure changed by the MF action. All of the mentioned changes are greater for the glass than for a more hydrophilic mica surface and depend upon the time of MF exposure and its strength. The magnetic field effect on the changes of the surface-free energy parameters for the mica and glass is opposite what may be due to the difference in the surface hydrophilicity. A “magnetic memory” effect was also found. The effect of MF on the water surface tension depends on the circulation time. It increases with the field duration. Moreover, the changes in the work of water adhesion indicate the possibility of solid surface wettability changes by the external MF water treatment. However, these are preliminary results that need further confirmation by other techniques.

Surface Free Energy of Boron-Compounds Modified Poplar Veneer

2013 ◽  
Vol 753-755 ◽  
pp. 843-847 ◽  
Author(s):  
Chen Chen Li ◽  
Zhi Yong Qin ◽  
Qian Zhang ◽  
Jiang Zhang Li
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Surface Free Energy ◽  
Sessile Drop ◽  
Untreated Wood ◽  
Initial Contact ◽  
Boron Compounds ◽  
Acid Base ◽  
The Difference ◽  
Better Than

The contact angle of three different reference liquids (i.e. distilled water, diiodomethane, and formamide) was measured by the sessile drop method by gently placing droplet onto the surface of the boron-compounds treated poplar veneer in this study. The permeability of the modified poplar veneer was evaluated. The surface free energy, as well as two components, namely, Lifshizvander Waals(LW) and Acid-base(AB), were calculated by the Acid-base theory, whereas the polar and nonpolar components were calculated according to the OWRK theory. The result shows that the initial contact angle of boron-compounds modified poplar veneer are significantly less than the untreated wood, which indicates that the wettability of boron-compounds polar veneer is better than the untreated wood. The same situation applies to the permeability. In addition, the surface free energy of boron-compounds modified poplar veneer is reduced, but the difference is very small.

The Model for Calculation the Hall Effect Parameter

2004 ◽  
Vol 9 (2) ◽  
pp. 129-138
Author(s):  
J. Kleiza ◽  
V. Kleiza
Keyword(s):  
Magnetic Field ◽  
Field Effect ◽  
Magnetic Field Effect ◽  
Mapping Method ◽  
Sample Thickness ◽  
System Of Nonlinear Equations ◽  
Specific Resistivity ◽  
Conformal Mapping Method ◽  
Effect Parameter ◽  
The Magnetic Field

A method for calculating the values of specific resistivity ρ as well as the product µHB of the Hall mobility and magnetic induction on a conductive sample of an arbitrary geometric configuration with two arbitrary fitted current electrodes of nonzero length and has been proposed an grounded. During the experiment, under the constant value U of voltage and in the absence of the magnetic field effect (B = 0) on the sample, the current intensities I(0), IE(0) are measured as well as the mentioned parameters under the effect of magnetic fields B1, B2 (B1 ≠ B2), i.e.: IE(β(i)), I(β(i)), i = 1, 2. It has been proved that under the constant difference of potentials U and sample thickness d, the parameters I(0), IE(0) and IE(β(i)), I(β(i)), i = 1, 2 uniquely determines the values of the product µHB and specific resistivity ρ of the sample. Basing on the conformal mapping method and Hall’s tensor properties, a relation (a system of nonlinear equations) between the above mentioned quantities has been found.

The magnetic field effect on heat-exchange characteristics and MHD resistance of lead-bismuth eutectic flow in the TOKAMAK blanket heat-sink systems

2013 ◽  
Vol 49 (1-2) ◽  
pp. 237-248
Author(s):  
A. V. Beznosov ◽  
O. O. Novozhilova ◽  
S. Yu. Savinov ◽  
M. V. Yarmonov ◽  
R. E. Alekseev
Keyword(s):  
Magnetic Field ◽  
Heat Exchange ◽  
Heat Sink ◽  
Field Effect ◽  
Magnetic Field Effect ◽  
Lead Bismuth Eutectic ◽  
The Magnetic Field

Bifunctional Composites for Biofilms Modulation on Cervical Restorations

2021 ◽  
pp. 002203452110181
Author(s):  
A.A. Balhaddad ◽  
I.M. Garcia ◽  
L. Mokeem ◽  
M.S. Ibrahim ◽  
F.M. Collares ◽  
...  
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Contact Angles ◽  
Bacterial Biofilm ◽  
Dental Composite ◽  
Log P ◽  
Rrna Gene ◽  
Cervical Lesions ◽  
Biofilm Growth ◽  
Biofilm Development

Cervical composites treating root carious and noncarious cervical lesions usually extend subgingivally. The subgingival margins of composites present poor plaque control, enhanced biofilm accumulation, and cause gingival irritation. A potential material to restore such lesions should combine agents that interfere with bacterial biofilm development and respond to acidic conditions. Here, we explore the use of new bioresponsive bifunctional dental composites against mature microcosm biofilms derived from subgingival plaque samples. The designed formulations contain 2 bioactive agents: dimethylaminohexadecyl methacrylate (DMAHDM) at 3 to 5 wt.% and 20 wt.% nanosized amorphous calcium phosphate (NACP) in a base resin. Composites with no DMAHDM and NACP were used as controls. The newly formulated 5% DMAHDM–20% NACP composite was analyzed by micro-Raman spectroscopy and transmission electron microscopy. The wettability and surface-free energy were also assessed. The inhibitory effect on the in vitro biofilm growth and the 16S rRNA gene sequencing of survival bacterial colonies derived from the composites were analyzed. Whole-biofilm metabolic activity, polysaccharide production, and live/dead images of the biofilm grown over the composites complement the microbiological assays. Overall, the designed formulations had higher contact angles with water and lower surface-free energy compared to the commercial control. The DMAHDM-NACP composites significantly inhibited the growth of total microorganisms, Porphyromonas gingivalis, Prevotella intermedia/nigrescens, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum by 3 to 5-log ( P < 0.001). For the colony isolates from control composites, the composition was typically dominated by the genera Veillonella, Fusobacterium, Streptococcus, Eikenella, and Leptotrichia, while Fusobacterium and Veillonella dominated the 5% DMAHDM–20% NACP composites. The DMAHDM-NACP composites contributed to over 80% of reduction in metabolic and polysaccharide activity. The suppression effect on plaque biofilms suggested that DMAHDM-NACP composites might be used as a bioactive material for cervical restorations. These results may propose an exciting path to prevent biofilm growth and improve dental composite restorations’ life span.

Strong Magnetic Field Effect on Surface Tension Associated with an Interfacial Magnetic Pressure

2012 ◽  
Vol 116 (33) ◽  
pp. 17676-17681 ◽  
Author(s):  
Z.H.I. Sun ◽  
X. Guo ◽  
M. Guo ◽  
C. Li ◽  
J. Vleugels ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Surface Tension ◽  
Strong Magnetic Field ◽  
Field Effect ◽  
Magnetic Field Effect ◽  
Magnetic Pressure

scholarly journals First in-orbit results of the vector magnetic field measurement of the High Precision Magnetometer onboard the China Seismo-Electromagnetic Satellite

2019 ◽  
Vol 71 (1) ◽  
Author(s):  
Bin Zhou ◽  
Bingjun Cheng ◽  
Xiaochen Gou ◽  
Lei Li ◽  
Yiteng Zhang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Precision ◽  
Magnetic Field Measurement ◽  
Vector Data ◽  
Magnetic Field Data ◽  
Night Side ◽  
The Difference ◽  
The Magnetic Field ◽  
Ground Calibration ◽  
Data Calibration

Abstract The High Precision Magnetometer (HPM) is one of the main payloads onboard the China Seismo-Electromagnetic Satellite (CSES). The HPM consists of two Fluxgate Magnetometers (FGM) and the Coupled Dark State Magnetometer (CDSM), and measures the magnetic field from DC to 15 Hz. The FGMs measure the vector components of the magnetic field; while the CDSM detects the magnitude of the magnetic field with higher accuracy, which can be used to calibrate the linear parameters of the FGM. In this paper, brief descriptions of measurement principles and performances of the HPM, ground, and in-orbit calibration results of the FGMs are presented, including the thermal drift and magnetic interferences from the satellite. The HPM in-orbit vector data calibration includes two steps: sensor non-linearity corrections based on on-ground calibration and fluxgate linear parameter calibration based on the CDSM measurements. The calibration results show a reasonably good stability of the linear parameters over time. The difference between the field magnitude calculated from the calibrated FGM components and the magnitude directly measured by the CDSM is just 0.5 nT (1σ) when the linear parameters are fitted separately for the day- and the night-side. Satellite disturbances have been analyzed including soft and hard remanence as well as magnetization of the magnetic torquer, radiation from the Tri-Band Beacon, and interferences from the rotation of the solar wing. A comparison shows consistency between the HPM and SWARM magnetic field data. Observation examples are introduced in the paper, which show that HPM data can be used to survey the global geomagnetic field and monitor the magnetic field disturbances in the ionosphere.

The Magnetic Anisotropy of Stretched Rubber as a Function of the Tension to Which It Is Subjected

1945 ◽  
Vol 18 (1) ◽  
pp. 8-9 ◽  
Author(s):  
Eugénie Cotton-Feytis
Keyword(s):  
Magnetic Field ◽  
Magnetic Anisotropy ◽  
Uniaxial Crystal ◽  
Horizontal Magnetic Field ◽  
First Approximation ◽  
The Difference ◽  
The Times ◽  
Angular Displacements ◽  
The Magnetic Field ◽  
Oscillation Method

Abstract From the standpoint of its magnetic anisotropy, stretched rubber is comparable in a first approximation to a uniaxial crystal, in which the direction of the axis is the same as the direction of elongation. It is possible to measure this anisotropy by means of the oscillation method used by Krishnan, Guha and Banerjee in studying crystals. The sample to be examined is suspended in a uniform horizontal magnetic field in such a manner that its axis is horizontal. It is then so arranged that the torsion of the suspension wire is zero when the rubber sample is in a position of equilibrium in the field. The times of oscillation T′ and T for very small angular displacements around this position, in the presence and then in the absence of the magnetic field, are then recorded. In this way the difference between the specific susceptibilities in the direction of the axis and in the horizontal direction perpendicular to the axis is calculated by application of the equation:

Effect of a static magnetic field onEscherichia coliadhesion and orientation

2016 ◽  
Vol 62 (11) ◽  
pp. 944-952 ◽  
Author(s):  
Lotfi Mhamdi ◽  
Nejib Mhamdi ◽  
Naceur Mhamdi ◽  
Philippe Lejeune ◽  
Nicole Jaffrezic ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Bacterial Adhesion ◽  
Parallel Magnetic Field ◽  
Field Orientation ◽  
Static Magnetic Fields ◽  
Preliminary Study ◽  
The Difference ◽  
The Magnetic Field

This preliminary study focused on the effect of exposure to 0.5 T static magnetic fields on Escherichia coli adhesion and orientation. We investigated the difference in bacterial adhesion on the surface of glass and indium tin oxide-coated glass when exposed to a magnetic field either perpendicular or parallel to the adhesion surface (vectors of magnetic induction are perpendicular or parallel to the adhesion surface, respectively). Control cultures were simultaneously grown under identical conditions but without exposure to the magnetic field. We observed a decrease in cell adhesion after exposure to the magnetic field. Orientation of bacteria cells was affected after exposure to a parallel magnetic field. On the other hand, no effect on the orientation of bacteria cells was observed after exposure to a perpendicular magnetic field.

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