scholarly journals EFFECT OF MECHANOCHEMICAL TREATMENT OF INGREDIENTS ON STRUCTURE AND PROPERTIES OF RUBBER MIXTURES AND RUBBERS ON BASIS ОF 1,4-CIS-POLYISOPRENE

2020 ◽  
Vol 63 (5) ◽  
pp. 89-93
Author(s):  
Vladimir M. Makarov ◽  
Elena L. Nikitina ◽  
Olga Yu. Solovyeva
Keyword(s):  
Magnetic Field ◽  
Zinc Oxide ◽  
Carbon Black ◽  
Mechanochemical Activation ◽  
Mechanochemical Treatment ◽  
Structure And Properties ◽  
Electrical Grid ◽  
Magnetic Elements ◽  
The Magnetic Field

The effect of the mechanochemical treatment of components of the sulphurous vulcanizing group on the properties of rubber mixtures and rubbers on the basis of 1,4-cis-polyisopren, filled with carbon black N330, was investigated. The mechanochemical activation of the components was carried out by processing them in a device that is a reactor with magnetic elements and a coil of inductivity. When connecting the inductor to the electrical grid, the working elements are exposed to the magnetic field and began to move intensiocly way with the transfer of energy to powdered particles. The treatment of both individual components: zinc oxide, accelerators, and all components of the sulfur vulcanizing group leads to an increase in the rate and degree of structuring of rubber in the main vulcanization period and a decrease in the tendency of rubber to reverse in the postvulcanization stage. In this case the values of elasticity modules increase and mechanical losses in vulcanizates reduce as the temperature increases. Most of these changes in the properties of mixtures and rubbers are expressed in the processing of individual accelerators and together all components of the vulcanizing group. Storage of activated ingredients for 30 days does not lead to significant changes in the structure and properties of rubber mixtures and vulcanizates.

scholarly journals Photospheric magnetic structure of coronal holes

2019 ◽  
Vol 629 ◽  
pp. A22 ◽  
Author(s):  
Stefan J. Hofmeister ◽  
Dominik Utz ◽  
Stephan G. Heinemann ◽  
Astrid Veronig ◽  
Manuela Temmer
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Coronal Hole ◽  
Magnetic Structure ◽  
Coronal Holes ◽  
Line Of Sight ◽  
Magnetic Elements ◽  
Background Magnetic Field ◽  
The Individual ◽  
The Magnetic Field

In this study, we investigate in detail the photospheric magnetic structure of 98 coronal holes using line-of-sight magnetograms of SDO/HMI, and for a subset of 42 coronal holes using HINODE/SOT G-band filtergrams. We divided the magnetic field maps into magnetic elements and quiet coronal hole regions by applying a threshold at ±25 G. We find that the number of magnetic bright points in magnetic elements is well correlated with the area of the magnetic elements (cc = 0.83 ± 0.01). Further, the magnetic flux of the individual magnetic elements inside coronal holes is related to their area by a power law with an exponent of 1.261 ± 0.004 (cc = 0.984 ± 0.001). Relating the magnetic elements to the overall structure of coronal holes, we find that on average (69 ± 8)% of the overall unbalanced magnetic flux of the coronal holes arises from long-lived magnetic elements with lifetimes > 40 h. About (22 ± 4)% of the unbalanced magnetic flux arises from a very weak background magnetic field in the quiet coronal hole regions with a mean magnetic field density of about 0.2−1.2 G. This background magnetic field is correlated to the flux of the magnetic elements with lifetimes of > 40 h (cc = 0.88 ± 0.02). The remaining flux arises from magnetic elements with lifetimes < 40 h. By relating the properties of the magnetic elements to the overall properties of the coronal holes, we find that the unbalanced magnetic flux of the coronal holes is completely determined by the total area that the long-lived magnetic elements cover (cc = 0.994 ± 0.001).

scholarly journals Solar and stellar magnetic flux tubes

1996 ◽  
Vol 176 ◽  
pp. 201-216
Author(s):  
Sami K. Solanki
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Magnetic Flux ◽  
Large Range ◽  
The Sun ◽  
Flux Tubes ◽  
Magnetic Elements ◽  
Turbulent Pressure ◽  
Magnetic Flux Tubes ◽  
The Magnetic Field

The magnetic field of the Sun is mainly concentrated into intense magnetic flux tubes having field strengths of the order of 1 kG. In this paper an overview is given of the thermal and magnetic properties of these flux tubes, which are known to exhibit a large range in size, from the smallest magnetic elements to sunspots. Differences and similarities between the largest and smallest features are stressed. Some thoughts are also presented on how the properties of magnetic flux tubes are expected to scale from the solar case to that of solar-like stars. For example, it is pointed out that on giants and supergiants turbulent pressure may dominate over gas pressure as the main confining agent of the magnetic field. Arguments are also presented in favour of a highly complex magnetic geometry on very active stars. Thus the very large starspots seen in Doppler images probably are conglomerates of smaller (but possibly still sizable) spots.

HYDROTHERMAL SYNTHESIS OF ZnO NANOSTRUCTURES UNDER HIGH PULSED MAGNETIC FIELD

2009 ◽  
Vol 23 (17) ◽  
pp. 3655-3659 ◽  
Author(s):  
ZHUN WANG ◽  
MINGYUAN ZHU ◽  
YING LI ◽  
HONGMING JIN ◽  
ZHENZHEN ZHU ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Zinc Oxide ◽  
Hydrothermal Synthesis ◽  
Hydrothermal Method ◽  
Nucleation And Growth ◽  
Pulsed Magnetic Field ◽  
Zno Nanostructures ◽  
Zno Particles ◽  
The Magnetic Field

Crystalline zinc oxide (ZnO) particles with different morphologies have been synthesized by the hydrothermal method under the magnetic field. It is found that the magnetic field influences the nucleation and growth of ZnO crystals. ZnO crystals obtained under high pulsed magnetic field were more uniform and well integrated.

Improved Oil Recovery by High Magnetic Flux Density Subjected to Iron Oxide Nanofluids

2013 ◽  
Vol 26 ◽  
pp. 89-99 ◽  
Author(s):  
Noorhana Yahya ◽  
Muhammad Kashif ◽  
Afza Shafie ◽  
Hasan Soleimani ◽  
Hasnah Mohd Zaid ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Zinc Oxide ◽  
Iron Oxide ◽  
Oil Recovery ◽  
Signal Strength ◽  
Initial Permeability ◽  
Magnetic Flux Density ◽  
Low Loss ◽  
Em Field ◽  
The Magnetic Field

Oil recovery in offshore environments can be increased by using nanofluids with electromagnetic waves generated from an antenna in the oil reservoir. In the case of offshore environments, these constraints can be avoided if a horizontal antenna is towed close to the seabed, which maximises the electromagnetic energy transferred from the overburden to the reservoir and nanofluids in the reservoir. In this research, a new enhanced antenna is used with iron oxide (Fe2O3) and zinc oxide (ZnO) nanofluids for oil recovery applications at the laboratory scale. In the antenna study, it was observed that the curve antenna with magnetic feeders gave a 1978% increase in the magnetic field signal strength compared to the case without magnetic feeders. The curve antenna with magnetic feeders produced a 473% increase in the electric field signal strength compared to the case without magnetic feeders. Iron oxide (Fe2O3) nanoparticles were prepared by the sol-gel method. The iron oxide (Fe2O3) nanoparticle sizes were in the range of 30.27-37.60 nm. FESEM and HRTEM images show that the samples have good crystallinity and that the grain size increased as temperature increased. Iron oxide (Fe2O3) samples sintered at 500°C showed a high initial permeability and Q-factor and a low loss factor compared to samples sintered at 500°C. The sample had a very high initial permeability and a low loss at low frequencies; therefore, it was suitable for the preparation of the nanofluid and oil recovery applications. Oil recovery through the usage of 0.1 % (w/w) iron oxide (Fe2O3) nanofluid with an EM field generated from the curve antenna with magnetic feeders was 33.45% of OOIP (original oil in place). In a similar case where 0.1 % (w/w) zinc oxide (ZnO) nanofluid with an EM field was used, 22.46 % of OOIP was recovered. These results imply that injecting 0.1% w/w iron oxide nanofluid coupled to the curve antenna with magnetic feeders has potential for oil recovery for improved water flooding systems because the high magnetic flux density that acts on the nanoparticles is proportional to the magnetic field strength.

scholarly journals The Earth's magnetic field in Southern Africa at the epoch, 1 July 1930

1947 ◽  
Vol 240 (818) ◽  
pp. 251-294 ◽  
Keyword(s):  
Magnetic Field ◽  
High Rate ◽  
Earth’S Magnetic Field ◽  
Magnetic Elements ◽  
Magnetic Inclination ◽  
Actual Observation ◽  
Earth's Magnetic Field ◽  
South West Africa ◽  
Linear Manner ◽  
The Magnetic Field

This paper is an attempt to determine the earth’s magnetic field in that part of Africa lying to the south of the Zambesi and Kunene Rivers, at the epoch 1930-50. The data used are: (1) Measurements made at about seven hundred stations by a number of previous workers, during the period 1900 to 1925, and already published. (2) Observations at about fifty of these stations made by the present writer between 1928 and 1930. These have been used to determine the secular variation, and thus to deduce the 1930-50 values of the magnetic field at all the other stations. The magnetic inclination is found to have changed in an almost linear manner, the maximum rate occurring in South-West Africa. The horizontal intensity has diminished at a gradually increasing rate, the maximum change being near Cape Town. The declination appears to have varied at a high rate until about 1928, and much more slowly since then. The greatest total changes are found near Durban. The results are presented in the form suggested by Ljungdahl. Maps with highly smoothed isomagnetic lines are used to show the probable ‘normal’ values of three magnetic elements (declination, inclination, and horizontal intensity), i.e. the component of the field not due to local magnetic disturbance. At each point of actual observation is placed a symbol indicating to what extent the observed value differs from that obtained by interpolation between the isomagnetic lines.

scholarly journals Effects of High Magnetic Field Postannealing on Microstructure and Properties of Pulse Electrodeposited Co-Ni-P Films

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Donggang Li ◽  
Chun Wu ◽  
Qiang Wang ◽  
Jean-Paul Chopart ◽  
Jicheng He ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Magnetic Field ◽  
Structure And Properties ◽  
Microstructure And Properties ◽  
Field Annealing ◽  
Fcc Phase ◽  
Moderate Magnetic Field ◽  
The Right ◽  
Deposited Film ◽  
The Magnetic Field

The influence of high magnetic field annealing on the morphology, microstructure, and properties of pulsed-electrodeposited Co-Ni-P films was investigated. The as-deposited film with a rough surface changed into uniform nanocrystalline during the magnetic field annealing process. In particular, the formation of intestine-like appearance with spherical clusters vanishing is favored from a moderate magnetic field strength of 6 T, due to the polarized effects. Meantime, the diffraction peak (111) of α (fcc) phase shifts to the right direction, which is attributed to the fact that more Co atoms from phosphide phase are incorporated into the Ni lattice, in comparison with the case of annealing under 0 T and 12 T magnetic fields. The mechanical and magnetic properties of the films reach relative optimum values at B=6 T. The evolution of magneto-induced modification in the Co-Ni-P morphology, structure, and properties can be explained by the polarized effect and the diffusion-acceleration effect under a high magnetic field.

scholarly journals Empirical Models of Photospheric Flux Tubes

1990 ◽  
Vol 138 ◽  
pp. 103-120
Author(s):  
S.K. Solanki
Keyword(s):  
Magnetic Field ◽  
Velocity Field ◽  
Empirical Models ◽  
Size Spectrum ◽  
Flux Tubes ◽  
Magnetic Elements ◽  
Derived Properties ◽  
Quantitative Results ◽  
Magnetic Flux Tubes ◽  
The Magnetic Field

The empirically derived properties of magnetic flux tubes at both ends of the size spectrum, i.e. magnetic elements and sunspots, are reviewed. Emphasis is placed on quantitative results. The following parameters are discussed in greater detail: The strength and structure of the magnetic field, the temperature stratification and the structure of the velocity field.

scholarly journals Small Magnetostatic Flux Tubes

1977 ◽  
Vol 4 (2) ◽  
pp. 265-266
Author(s):  
H. C. Spruit
Keyword(s):  
Magnetic Field ◽  
Heat Transport ◽  
Convective Heat ◽  
Convection Zone ◽  
Solar Surface ◽  
Small Scale ◽  
Flux Tubes ◽  
Basic Assumptions ◽  
Magnetic Elements ◽  
The Magnetic Field

In an attempt to interpret the observed properties of small scale magnetic fields at the solar surface, a set of models has been calculated based on the assumption of a magnetostatic equilibrium. The basic assumptions made are: i.The observed magnetic elements are magnetostatic flux tubes.ii.The efficiency of convective heat transport inside the tube is reduced with respect to that in the normal convection zone; the horizontal convective heat transport in the tube is suppressed completely by the magnetic field.iii.Close to the tube, horizontal convective heat transport is reduced due to the proximity of the magnetic field.

Analysis of the He i chromosphere in relation to the magnetic field activity over solar cycle time periods

2020 ◽  
Vol 497 (1) ◽  
pp. 969-975
Author(s):  
K J Li ◽  
W Feng
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Active Regions ◽  
Solar Observatory ◽  
Small Scale ◽  
Large Magnetic Field ◽  
National Solar Observatory ◽  
Magnetic Elements ◽  
The Magnetic Field

ABSTRACT Solar synoptic maps of both He i 10 830 Å intensity and the magnetic field, which are observed by the Vacuum Telescope at National Solar Observatory/Kitt Peak from 2005 July to 2013 March are utilized to study relationship of He i intensity of the weakly magnetized chromosphere with the respective magnetic field strength. Strong absorption in He i intensity presents the butterfly-pattern latitude migration zone as active regions do, indicating that strong magnetic field corresponds to high-temperature structures of the active chromosphere. For He i intensity and magnetic field strength, their distribution at the time-latitude coordinate and their time series at each of the 180 measurement latitude are found to be significantly negatively correlated with each other in most cases. When a solar hemisphere is divided into three latitude bands: low, middle, and high latitude bands, and even after large magnetic field values not taken into account, they are still negatively correlated in most cases, and further when large magnetic field values are subtracted He i intensity varies more sensitively with magnetic field strength than the corresponding cases when large magnetic field values are not subtracted. He i intensity in the quiet chromosphere thus mainly presents a negative correlation with the magnetic field, and the heating of the quiet chromosphere is inferred to be caused mainly by small-scale magnetic elements.

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