Joule Heat Welding of Thin Platinum and Tungsten Wires and the Thermoelectric Effects Around Bi-Metal Junctions

2013 ◽  
Vol 1 (2) ◽  
Author(s):  
Hironori Tohmyoh ◽  
Tomochika Tanaka ◽  
Masato Fujimori ◽  
Masumi Saka
Keyword(s):  
Seebeck Effect ◽  
Joule Heat ◽  
The Other ◽  
Peltier Effect ◽  
Thermoelectric Effects ◽  
Thin Platinum ◽  
A Current ◽  
And Tungsten

Fine thermoelectric elements were fabricated on electrode chips by welding together the tips of thin 5 μm diameter Pt and W wires by Joule heat welding. The Pt/W junction was heated by bringing it into contact with a wire carrying a current, thus generating a voltage due to the Seebeck effect in the circuit containing the junction. The Pt/W junctions of two thermoelectric elements in separate circuits were brought into contact with each other. Current was supplied to one of the thermoelectric elements, while the temperature was measured using the other element as a thermocouple. The temperature, which is due to the Peltier effect, was found to depend on the direction of current supply.

Joule Heat Welding of Thin Metallic Wires and Thermoelectric Effects Around Dissimilar Metal Weld

2011 ◽  
Author(s):  
Hironori Tohmyoh ◽  
Tomochika Tanaka ◽  
Masato Fujimori ◽  
Masumi Saka
Keyword(s):  
Joule Heat ◽  
Peltier Effect ◽  
Thermoelectric Effects ◽  
Thermoelectric Element ◽  
Dissimilar Metal ◽  
Thin Wires ◽  
Dissimilar Metal Weld ◽  
Metallic Wires ◽  
The One ◽  
Metal Weld

Fine thermoelectric elements were fabricated on an electrode chip where the tips of the Pt and W thin wires having the diameter of 5 μm were welded together by Joule heat welding. Firstly, the dissimilar metal weld was contacted to thin wire heater and the voltage appeared in the circuit due to Seebeck effect was measured. Current was supplied to the one of the thermoelectric element and the temperature at the Pt/W weld was measured by the other element. It was found that the temperature at dissimilar metal weld depended on the direction of current and Peltier effect was successfully observed.

Rem Study of Current Effect on the Structure of Clean Si(111) Surface

1990 ◽  
Vol 48 (1) ◽  
pp. 306-307
Author(s):  
A. Yamanaka ◽  
H. Ohse ◽  
K. Yagi
Keyword(s):  
The Other ◽  
Current Direction ◽  
Clean Surface ◽  
Current Effect ◽  
Atomic Steps ◽  
Step Bunching ◽  
Terrace Width ◽  
Step Down ◽  
A Current

Recently current effects on clean and metal adsorbate surfaces have attracted much attention not only because of interesting phenomena but also because of practically importance in treatingclean and metal adsorbate surfaces [1-6]. In the former case, metals deposited migrate on the deposit depending on the current direction and a patch of the deposit expands on the clean surface [1]. The migration is closely related to the adsorbate structures and substrate structures including their anisotropy [2,7]. In the latter case, configurations of surface atomic steps depends on the current direction. In the case of Si(001) surface equally spaced array of monatom high steps along the [110] direction produces the 2x1 and 1x2 terraces. However, a relative terrace width of the two domain depends on the current direction; a step-up current widen terraces on which dimers are parallel to the current, while a step-down current widen the other terraces [3]. On (111) surface, a step-down current produces step bunching at temperatures between 1250-1350°C, while a step-up current produces step bunching at temperatures between 1050-1250°C [5].In the present paper, our REM observations on a current induced step bunching, started independently, are described.Our results are summarized as follows.(1) Above around 1000°C a step-up current induces step bunching. The phenomenon reverses around 1200 C; a step-down current induces step bunching. The observations agree with the previous reports [5].

Spatial Profile of Thermoelectric Effects During Peltier Pulsing in Bi and Bi/MnBi Eutectic

1986 ◽  
Vol 87 ◽  
Author(s):  
R. P. Silberstein ◽  
D. J. Larson
Keyword(s):  
Directional Solidification ◽  
Joule Heating ◽  
Current Density ◽  
Peltier Effect ◽  
Thomson Effect ◽  
Thermoelectric Effects ◽  
Spatial Profile ◽  
Thermal Transients ◽  
Solid Liquid Interface ◽  
Solid Liquid

AbstractWe have studied the spatial profile of the thermal transients that occur during and following the current pulsing associated with Peltier Interface Demarcation during directional solidification. Results for pure Bi are presented in detail and compared with corresponding results for the Bi/MnBi eutectic. Significant thermal transients occur throughout the sample that can be accounted for by the Peltier effect, the Thomson effect, and Joule heating. We have separated these effects and studied their behavior as a function of time, current density, and position with respect to the solid/liquid interface.

Ventricular fibrillation during uniform myocardial anoxia due to asphyxia

1960 ◽  
Vol 198 (5) ◽  
pp. 955-958 ◽  
Author(s):  
Jay D. Coffman ◽  
D. E. Gregg
Keyword(s):  
Cardiac Arrest ◽  
Ventricular Fibrillation ◽  
Potassium Level ◽  
Serum Potassium Level ◽  
Current Theory ◽  
The Other ◽  
Right Atrial ◽  
Serum Electrolytes ◽  
Anesthetized Dogs ◽  
A Current

Thirty-three anesthetized dogs of varying weights were subjected to complete asphyxia by tracheal occlusion to produce uniform anoxia of the heart. Eleven showed electrocardiographic evidence of ventricular fibrillation while the other twenty-two demonstrated cardiac arrest. The development of ventricular fibrillation correlated with the heavier body and heart weights and with a lower average right atrial serum potassium level as compared to the dogs not fibrillating. Other serum electrolytes, pH, body temperature and sex showed no correlation with the arrhythmia. The importance of the fact that large dogs have a greater susceptibility to develop ventricular fibrillation during uniform anoxia of the heart is discussed in relation to experimental research on dogs and to a current theory of the cause of ventricular fibrillation.

Statistics on Jupiter's Current Sheet with Juno Data: Geometry, Magnetic Fields and Energetic Particles

2021 ◽  
Author(s):  
Zhi-Yang Liu ◽  
Qiu-Gang Zong ◽  
Michel Blanc
Keyword(s):  
Magnetic Fields ◽  
Current Sheet ◽  
Power Law ◽  
Heavy Ions ◽  
Particle Interaction ◽  
The Other ◽  
Gaussian Functions ◽  
Fixed Energy ◽  
Thin Current Sheet ◽  
A Current

<p>Jupiter's magnetosphere contains a current sheet of huge size near its equator. The current sheet not only mediates the global mass and energy cycles of Jupiter's magnetosphere, but also provides an occurring place for many localized dynamic processes, such as reconnection and wave-particle interaction. To correctly evaluate its role in these processes, a statistical description of the current sheet is required. To this end, here we conduct statistics on Jupiter's current sheet, with four-year Juno data recorded in the 20-100 Jupiter radii, post-midnight magnetosphere. The results suggest a thin current sheet whose thickness is comparable with the gyro-radius of dominant ions. Magnetic fields in the current sheet decrease in power-law with increasing radial distances. At fixed energy, the flux of electrons and protons increases with decreasing radial distances. On the other hand, at fixed radial distances, the flux decreases in power-law with increasing energy. The flux also varies with the distances to the current sheet center. The corresponding relationship can be well described by Gaussian functions peaking at the current sheet center. In addition, the statistics show the flux of oxygen- and sulfur-group ions is comparable with the flux of protons at the same energy and radial distances, indicating the non-negligible effects of heavy ions on current sheet dynamics. From these results, a statistical model of Jupiter's current sheet is constructed, which provides us with a start point of understanding the dynamics of the whole Jupiter's magnetosphere.</p>

scholarly journals Analysis of self-heating of thermally assisted spin-transfer torque magnetic random access memory

2016 ◽  
Vol 7 ◽  
pp. 1676-1683 ◽  
Author(s):  
Austin Deschenes ◽  
Sadid Muneer ◽  
Mustafa Akbulut ◽  
Ali Gokirmak ◽  
Helena Silva
Keyword(s):  
Random Access ◽  
Random Access Memory ◽  
Spin Transfer Torque ◽  
Peltier Effect ◽  
Heating Process ◽  
Tunneling Junction ◽  
Access Memory ◽  
Thermoelectric Effects ◽  
Magnetic Random Access Memory ◽  
Self Heating

Thermal assistance has been shown to significantly reduce the required operation power for spin torque transfer magnetic random access memory (STT-MRAM). Proposed heating methods include modified material stack compositions that result in increased self-heating or external heat sources. In this work we analyze the self-heating process of a standard perpendicular magnetic anisotropy STT-MRAM device through numerical simulations in order to understand the relative contributions of Joule, thermoelectric Peltier and Thomson, and tunneling junction heating. A 2D rotationally symmetric numerical model is used to solve the coupled electro-thermal equations including thermoelectric effects and heat absorbed or released at the tunneling junction. We compare self-heating for different common passivation materials, positive and negative electrical current polarity, and different device thermal anchoring and boundaries resistance configurations. The variations considered are found to result in significant differences in maximum temperatures reached. Average increases of 3 K, 10 K, and 100 K for different passivation materials, positive and negative polarity, and different thermal anchoring configurations, respectively, are observed. The highest temperatures, up to 424 K, are obtained for silicon dioxide as the passivation material, positive polarity, and low thermal anchoring with thermal boundary resistance configurations. Interestingly it is also found that due to the tunneling heat, Peltier effect, device geometry, and numerous interfacial layers around the magnetic tunnel junction (MTJ), most of the heat is dissipated on the lower potential side of the magnetic junction. This asymmetry in heating, which has also been observed experimentally, is important as thermally assisted switching requires heating of the free layer specifically and this will be significantly different for the two polarity operations, set and reset.

scholarly journals The Fundamental Research of Thermoelectric Effects : Ist Report, Two-dimensional Seebeck Effect

1975 ◽  
Vol 18 (115) ◽  
pp. 25-32 ◽  
Author(s):  
Hiromichi UMEMIYA ◽  
Masachika ITOO ◽  
Toshiaki KIKUCHI
Keyword(s):  
Seebeck Effect ◽  
Two Dimensional ◽  
Thermoelectric Effects ◽  
Fundamental Research

Spanish Morphophonology

2011 ◽  
Vol 4 (1) ◽  
Author(s):  
Sonia Colina
Keyword(s):  
The Other ◽  
Current View ◽  
Phonological Processes ◽  
Other Hand ◽  
Word Classes ◽  
Active Phenomenon ◽  
A Current ◽  
Sizable Number

AbstractIn recent years a sizable number of morphophonological phenomena have attracted considerable attention from Spanish phonologists. This article presents a current view of the controversies within the context of two recurring topics: the validity of morphophonological generalizations and the interaction of morphological and phonological processes. Some of the processes discussed are velar and coronal softening, diphthongization, word-classes, stem formatives, nasal depalatalization, diminutive formation and the nature of final -e. It is shown that some phenomena cannot be said to be synchronically active (i.e. coronal and velar softening, final epenthesis, diphthongization, and depalatalization), consisting instead of lexicalized alternants. Plural epenthesis, on the other hand, is argued (contra Bonet) to be an active phenomenon. Pluralization and diminutive formation are said to be morphophonological, not just phonological. Finally, the article addresses the connection between the interaction of morphological and phonological processes to the design of the morphophonological component of the grammar, introducing the issue of a derivational element in non-derivational models of phonology.

Chemical nitrogen fixation by using molybdenum and tungsten complexes

2001 ◽  
Vol 73 (2) ◽  
pp. 261-263 ◽  
Author(s):  
Masanobu Hidai ◽  
Yasushi Mizobe
Keyword(s):  
Nitrogen Fixation ◽  
The Other ◽  
Nucleophilic Attack ◽  
Dinuclear Complexes ◽  
Tungsten Complexes ◽  
Other Hand ◽  
Dinitrogen Complexes ◽  
Dinitrogen Complex ◽  
Moderate Yield ◽  
And Tungsten

Dinitrogen complex cis-[W (N2) 2 (PMe2Ph) 4] reacts with an excess of acidic dihydrogen complexes such as trans-[RuCl (h2-H2) (dppe) 2]BF4 (dppe = 1,2-bis (diphenylphosphino) ethane) at 55 °C under 1 atm of H2 to form ammonia in moderate yield. The reaction is presumed to proceed through nucleophilic attack of the remote nitrogen of the coordinated dinitrogen on the dihydrogen ligand. The coordinated dinitrogen is also protonated by treatment with hydrosulfido-bridged dinuclear complexes such as [Cp*Ir (m-SH) 3IrCp*]Cl (Cp* = h5-C5Me5) to afford ammonia. On the other hand, the synthetic cycle for the formation of pyrrole and N-aminopyrrole from dinitrogen and 2,5-dimethoxytetrahydrofuran has been established starting from dinitrogen complexes of the type trans-[M (N2) 2 (dppe) 2 ] (M = Mo, W).

The analysis of molybdates and tungstates

1966 ◽  
Vol 35 (275) ◽  
pp. 995-1002 ◽  
Author(s):  
A. J. Easton ◽  
A. A. Moss
Keyword(s):  
Optical Density ◽  
Wave Length ◽  
Ultra Violet ◽  
The Other ◽  
The Common ◽  
Significant Interference ◽  
And Tungsten

SummaryThe estimation of molybdenum and tungsten when present together has proved difficult, as is indicated by the large number of methods put forward for their determination. Many of the methods given are for one or other of these elements only, a note often being added that the presence of the other invalidates the method. The estimation of molybdate and tungstate in the mineral powellite has been briefly described by one of the authors (A. A. M.): molybdate and tungstate were precipitated as oxinates (Mo,W)O2(C9H6ON)2 and the molybdate (MoO4″) determined by measurement of the optical density at 230 mµ of a solution containing molybdate and tungstate. The amount of tungstate present was then estimated by difference. The property of the molybdate ion, MoO4″, to absorb strongly in the ultra-violet has been further investigated and it has been found that, if a wave-length of 240 mµ is chosen and the proper precautions taken, the MoO4″ ion can be estimated without significant interference by the WO4″ ion. Methods are given for the analysis of the common molybdate and tungstate minerals, together with results obtained during the course of this investigation.

Sign in / Sign up

Export Citation Format

Share Document