226 research outputs found
Halbach Magnets for Magnetic Resonance
This review is a compilation of relevant concepts in designing Halbach
multipoles for magnetic resonance applications. The main focus is on providing
practical guidelines to plan, design and build such magnets. Therefore,
analytical equations are presented for estimating the magnetic field from ideal
to realistic systems. Various strategies of homogenizing magnetic fields are
discussed together with concepts of opening such magnets without force, or
combining them for variable fields. Temperature compensation and other
practical aspects are also reviewed. For magnetic resonance two polarities (di-
and quadrupole) are of main interest, but higher polarities are also included.Comment: 37 pages, 17 Figure
Ultrasensitive 3He magnetometer for measurements of high magnetic fields
We describe a 3He magnetometer capable to measure high magnetic fields (B >
0.1 Tesla) with a relative accuracy of better than 10^-12. Our approach is
based on the measurement of the free induction decay of gaseous, nuclear spin
polarized 3He following a resonant radio frequency pulse excitation. The
measurement sensitivity can be attributed to the long coherent spin precession
time T2* being of order minutes which is achieved for spherical sample cells in
the regime of motional narrowing where the disturbing influence of field
inhomogeneities is strongly suppressed. The 3He gas is spin polarized in-situ
using a new, non-standard variant of the metastability exchange optical
pumping. We show that miniaturization helps to increase T2* further and that
the measurement sensitivity is not significantly affected by temporal field
fluctuations of order 10^-4.Comment: 27 pages, 7 figure
Π Π°Π·ΡΠ°Π±ΠΎΡΠΊΠ° ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΌΡ Π΄Π»Ρ ΡΠ°ΡΡΠ΅ΡΠ° Π±ΡΡΠΎΠ²Π·ΡΡΠ²Π½ΡΡ ΡΠ°Π±ΠΎΡ Π² Π²Π΅ΡΡΠΈΠΊΠ°Π»ΡΠ½ΠΎΠΌ ΡΡΠ²ΠΎΠ»Π΅
ΠΠ½Π°Π»ΠΈΠ· ΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠ°ΡΡΠΈ ΠΠ΅Π»ΠΎΠ²ΡΠΊΠΎΠΉ ΠΠ ΠΠ‘ ΠΈ ΡΠ΅Π»Π΅ΠΉΠ½Π°Ρ Π·Π°ΡΠΈΡΠ° Π±Π»ΠΎΠΊΠ° Π³Π΅Π½Π΅ΡΠ°ΡΠΎΡ-ΡΡΠ°Π½ΡΡΠΎΡΠΌΠ°ΡΠΎΡ
ΠΡΠΏΡΡΠΊΠ½Π°Ρ ΠΊΠ²Π°Π»ΠΈΡΠΈΠΊΠ°ΡΠΈΠΎΠ½Π½Π°Ρ ΡΠ°Π±ΠΎΡΠ° 118 Ρ., 24 ΡΠΈΡ., 21 ΡΠ°Π±Π»., 17 ΠΈΡΡΠΎΡΠ½ΠΈΠΊΠΎΠ², 6 ΠΏΡΠΈΠ». ΠΠ±ΡΠ΅ΠΊΡΠΎΠΌ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΠ΅Π»ΠΎΠ²ΡΠΊΠ°Ρ ΠΠ ΠΠ‘. Π¦Π΅Π»Ρ ΡΠ°Π±ΠΎΡΡ Π·Π°ΠΊΠ»ΡΡΠ°Π΅ΡΡΡ Π² Π°Π½Π°Π»ΠΈΠ·Π΅ ΡΠ»Π΅ΠΊΡΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΡΠ°ΡΡΠΈ ΠΠ΅Π»ΠΎΠ²ΡΠΊΠΎΠΉ ΠΠ ΠΠ‘ (Π°Π½Π°Π»ΠΈΠ· ΡΡΡΡΠΊΡΡΡΠ½ΠΎΠΉ ΡΡ
Π΅ΠΌΡ, Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΈ ΠΎΠ±ΠΎΡΡΠ΄ΠΎΠ²Π°Π½ΠΈΡ, ΡΠ°ΡΡΠ΅Ρ Π±Π°Π»Π°Π½ΡΠ° ΠΌΠΎΡΠ½ΠΎΡΡΠ΅ΠΉ ΠΈ Ρ.Π΄.) ΠΈ ΡΠ°ΡΡΠ΅ΡΠ΅ ΡΠ΅Π»Π΅ΠΉΠ½ΠΎΠΉ Π·Π°ΡΠΈΡΡ Π±Π»ΠΎΠΊΠ° Π³Π΅Π½Π΅ΡΠ°ΡΠΎΡ β Π΄Π²ΡΡ
ΠΎΠ±ΠΌΠΎΡΠΎΡΠ½ΡΠΉ ΡΡΠ°Π½ΡΡΠΎΡΠΌΠ°ΡΠΎΡ.
ΠΠ»Ρ Π΄ΠΎΡΡΠΈΠΆΠ΅Π½ΠΈΡ ΠΏΠΎΡΡΠ°Π²Π»Π΅Π½Π½ΠΎΠΉ ΡΠ΅Π»ΠΈ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½Ρ ΡΠ°ΡΡΠ΅ΡΠ½ΡΠ΅ ΠΈ Π³ΡΠ°ΡΠΎΠ°Π½Π°Π»ΠΈΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΌΠ΅ΡΠΎΠ΄Ρ, Π²ΡΡΠΈΡΠ»ΠΈΡΠ΅Π»ΡΠ½ΡΠ΅ ΡΠ°ΡΡΠ΅ΡΠ½ΡΠ΅ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΡ CTCURR, ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΌΠ° Π΄Π»Ρ ΡΠ°ΡΡΠ΅ΡΠ° ΠΏΡΠΎΠ΄ΠΎΠ»ΠΆΠΈΡΠ΅Π»ΡΠ½ΡΡ
ΡΠ΅ΠΆΠΈΠΌΠΎΠ² ΡΠ»Π΅ΠΊΡΡΠΎΡΡΠ°Π½ΡΠΈΠΈ Β«ΠΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ ΡΡΡΡΠΊΡΡΡΠ½ΡΡ
ΡΡ
Π΅ΠΌ ΠΠΠ‘ Ρ Π°Π²ΡΠΎΡΡΠ°Π½ΡΡΠΎΡΠΌΠ°ΡΠΎΡΠ°ΠΌΠΈ ΡΠ²ΡΠ·ΠΈΒ», ΠΏΠ°ΠΊΠ΅ΡΡ ΠΏΡΠΎΠ³ΡΠ°ΠΌΠΌ Mathcad, Excel, Π³ΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΠΉ ΡΠ΅Π΄Π°ΠΊΡΠΎΡ MS Visio.
Π ΠΏΡΠΎΡΠ΅ΡΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠ»ΠΈΡΡ Π°Π½Π°Π»ΠΈΠ·Ρ ΠΏΡΠΎΠ΄ΠΎΠ»ΠΆΠΈΡΠ΅Π»ΡΠ½ΡΡ
ΡΠ΅ΠΆΠΈΠΌΠΎΠ² ΡΠ»Π΅ΠΊΡΡΠΎΡΡΠ°Π½ΡΠΈΠΈ ΠΈ ΡΠ°ΡΡΠ΅Ρ ΡΠΎΠΊΠΎΠ² ΠΊΠΎΡΠΎΡΠΊΠΈΡ
Π·Π°ΠΌΡΠΊΠ°Π½ΠΈΠΉ.Final qualifying work 118 p., 24 fig., 21 tab., 17 sources, 6 adj. The object of this study is to Belovo TPP. The purpose of work is to analyze the electrical Belovskaya GRES (analysis of structural scheme, the characteristics of the equipment, capacity balancing, etc.) and the calculation of relay protection unit generator - two-winding transformer.
To achieve this goal and estimates used graphoanalitical method, computer systems design CTCURR, a program for calculating the continuous duty power "Research of structural schemes IES with autotransformers connection" packages Mathcad software, Excel, MS Visio editing.
The study carried out extensive analyzes of power modes and calculation of short circuit currents
ΠΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡΠΈ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡ Π»Π°Π·Π΅ΡΠ½ΠΎΠΉ ΡΠ²Π°ΡΠΊΠΈ Π΄Π»Ρ Π½ΠΈΠ·ΠΊΠΎΡΠ³Π»Π΅ΡΠΎΠ΄ΠΈΡΡΠΎΠΉ ΠΏΡΠΎΠΌΡΡΠ»Π΅Π½Π½ΠΎΠΉ ΡΡΠ°Π»ΠΈ X80
ΠΠ±ΡΠ΅ΠΊΡΠΎΠΌ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΡΠ²Π»ΡΠ΅ΡΡΡ ΡΡΠ°Π»ΠΈ ΠΊΠ°ΡΠ΅Π³ΠΎΡΠΈΠΈ ΠΏΡΠΎΡΠ½ΠΎΡΡΠΈ Π₯80 ΠΏΠΎΡΠ»Π΅ ΠΊΠΎΠ½ΡΡΠΎΠ»ΠΈΡΡΠ΅ΠΌΠΎΠΉ ΠΏΡΠΎΠ΄ΠΎΠ»ΡΠ½ΠΎΠΉ ΠΏΡΠΎΠΊΠ°ΡΠΊΠΈ Ρ ΠΎΠΊΠΎΠ½ΡΠ°Π½ΠΈΠ΅ΠΌ ΠΏΡΠΎΠΊΠ°ΡΠΊΠΈ Π² (?+?) β ΠΎΠ±Π»Π°ΡΡΠΈ ΠΈ ΠΏΠΎΡΠ»Π΅Π΄ΡΡΡΠΈΠΌ ΡΡΠΊΠΎΡΠ΅Π½Π½ΡΠΌ ΠΎΡ
Π»Π°ΠΆΠ΄Π΅Π½ΠΈΠ΅ΠΌ.
Π¦Π΅Π»Ρ ΡΠ°Π±ΠΎΡΡ β ΠΈΠ·ΡΡΠΈΡΡ ΠΌΠΈΠΊΡΠΎΡΡΡΡΠΊΡΡΡΡ ΠΏΡΠΎΠΌΡΡΠ»Π΅Π½Π½ΠΎΠΉ ΡΡΡΠ±Π½ΠΎΠΉ ΡΡΠ°Π»ΠΈ ΠΊΠ°ΡΠ΅Π³ΠΎΡΠΈΠΈ ΠΏΡΠΎΡΠ½ΠΎΡΡΠΈ Π₯80 ΠΏΠΎΡΠ»Π΅ ΡΠ΅ΡΠΌΠΎΠΌΠ΅Ρ
Π°Π½ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠΈ, Π° ΡΠ°ΠΊΠΆΠ΅ ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎΡΡΠΈ ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΡΡΡΡΠΊΡΡΡ Π² Π·ΠΎΠ½Π΅ ΡΠ²Π°ΡΠ½ΠΎΠ³ΠΎ ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΡ ΡΡΠ°Π»ΠΈ Π₯80 ΠΏΠΎΠ΄ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΠ΅ΠΌ Π»Π°Π·Π΅ΡΠ½ΠΎΠΉ ΡΠ²Π°ΡΠΊΠΈ ΠΈ ΠΎΡΠ΅Π½ΠΈΡΡ ΠΌΠ΅Ρ
Π°Π½ΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠ²ΠΎΠΉΡΡΠ²Π° ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΡΡ
ΡΠ²Π°ΡΠ½ΡΡ
ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΠΉ.
ΠΠ½Π°ΡΠΈΠΌΠΎΡΡΡ ΡΠ°Π±ΠΎΡΡ Π·Π°ΠΊΠ»ΡΡΠ°Π΅ΡΡΡ Π² ΠΈΠ·ΡΡΠ΅Π½ΠΈΠΈ Π½ΠΎΠ²ΠΎΠΉ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΠΈ ΡΠΎΠ·Π΄Π°Π½ΠΈΡ ΡΠ²Π°ΡΠ½ΡΡ
ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΠΉ Π΄Π»Ρ Π³Π°Π·ΠΎ- ΠΈ Π½Π΅ΡΡΠ΅ΠΏΡΠΎΠ²ΠΎΠ΄ΠΎΠ² ΡΠ°Π±ΠΎΡΠ°ΡΡΠΈΡ
Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡ
Π½ΠΈΠ·ΠΊΠΈΡ
ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡ.The object of research is steel of strength category X80 after controlled longitudinal rolling with the end of rolling in the (? + ?) region and subsequent accelerated cooling.
The purpose of the work β is to study the microstructure of industrial pipe steel of strength category X80 after thermomechanical processing, as well as the features of the formation of structures in the weld zone of steel X80 under the influence of laser welding and to evaluate the mechanical properties of the welded joints.
The significance of the work consists in the study of a new technology for creating welded joints in gas and oil pipelines working in difficult climatic conditions
Design and development of the re-entry sensor system for the CubeSat mission SOURCE
With the number of man-made objects being launched into orbit steadily increasing, space debris is one of the big challenges for future space flight. In order to better assess the danger to humans on Earthβs surface, re-entry should be researched in more detail. SOURCE serves as a 3U+ satellite platform designed and developed by the small satellite student society (KSat e.V.) and the Institute of Space Systems (IRS) at the University of Stuttgart. It was selected by ESA in 2020 to be part of the βFly your Satelliteβ program, has successfully completed the CDR
and is currently preparing for the MRR. SOURCEβs objectives are education, verification of several cost-saving, not yet space-proven technologies for orbital use, capturing images of meteoroids entering Earth's atmosphere and documenting its own demise during re-entry by
analysing atomic oxygen, heat flux- and pressure data. In order to receive data for as long as possible during re-entry, the satellite switches from S-band to Iridium (inter-satellite link) communication at an altitude below 200 km.
For the in-situ measurement during the re-entry, SOURCE is equipped with two Flux-Phi-Probe (FIPEX) sensors for the measurement of atomic oxygen and five additional sensor arrays. Each array contains one pressure sensor and two heat flux sensors, one commercial and one
developed by the IRS. The arrays are placed at five positions in-line across the satellite to reduce effects of tumbling during the re-entry and to allow for the measurement of gradients.
For a first estimation of the expected value ranges, simulations were performed with the software PICLas, developed by the IRS and the Institute of Aero-and Gas Dynamics (IAG) at the University of Stuttgart. In an iterative process, the collected data will be used to further improve this simulation software after the re-entry of the SOURCE satellite.
The aim of this paper is to describe the design philosophy and development process of the sensor readout electronics. The tests carried out are presented and the first results are presented
- β¦