Nitrogen-induced increase of the maximum electron concentration in group III-N-V alloys

2000 ◽  
Vol 61 (20) ◽  
pp. R13337-R13340 ◽  
Author(s):  
K. M. Yu ◽  
W. Walukiewicz ◽  
W. Shan ◽  
J. W. Ager ◽  
J. Wu ◽  
...  
Keyword(s):  
Electron Concentration ◽  
Group Iii ◽  
Maximum Electron Concentration

scholarly journals Semiempirical model of the ionospheric maximum electron concentration for South American middle latitudes

1992 ◽  
Vol 31 (2) ◽  
pp. 125-129
Author(s):  
M. A. Arriagada ◽  
A. J. Foppiano
Keyword(s):  
Electron Concentration ◽  
Semiempirical Model ◽  
South American ◽  
Middle Latitudes ◽  
Maximum Electron Concentration

Se propone un modelo muy simple que da valores horarios de la máxima concentración electrónica en la ionosfera, representativa de las condiciones del verano, invierno y los equinoccios, para niveles de actividad solar tanto altos como bajos. La concentración de electrones se determina como la suma de dos términos, uno relacionado con los procesos fotoquímicos y difusivos y el otro con los mecanismos de transporte. Se dan expresiones analíticas simples para estos dos términos y los valores de la frecuencia crítica en la región F calculados usando estos términos se comparan con los valores observados en la isla de King George, Antártica y en Concepción, Chile.

QUASI-BALLISTIC AND OVERSHOOT TRANSPORT IN GROUP III-NITRIDES

2004 ◽  
Vol 14 (01) ◽  
pp. 127-154 ◽  
Author(s):  
K. W. KIM ◽  
V. A. KOCHELAP ◽  
V. N. SOKOLOV ◽  
S. M. KOMIRENKO
Keyword(s):  
Distribution Function ◽  
Electron Concentration ◽  
Peak Velocity ◽  
Electron Distribution Function ◽  
Time Dependent ◽  
Electron Velocity ◽  
High Electron ◽  
Electron Heating ◽  
Group Iii ◽  
High Fields

We analyze steady-state and transient electron transport in the group III-nitride materials at high and ultra-high electric fields for different electron concentration regimes. At high electron concentrations where the electron distribution function assumes a shifted Maxwellian, we investigate different time-dependent transient transport regimes through the phase-plane anyalysis. Unexpected electron heating pattern is observed during the velocity overshoot process with a moderate electron temperature near the peak velocity followed by rapid increase in the deceleration period. For short nitride diodes, space-charge limited transport is considered by taking into account the self-consistent field. In this case, the overshoot is weaker and the electron heating in the region of the peak velocity is greater than that found for time-dependent problem. The transient processes are extended to sufficiently larger distances as well. When the electron concentration is small, we propose a model which accounts the main features of injected electrons in a short device with high fields. The electron velocity distribution over the device is found as a function of the field. It is demonstrated that in high fields the electrons are characterized by the extreme distribution function with the population inversion.

Ultrastructural Lesions Produced by Alcohol and Sucrose in the Heart and Liver of C57BL Mice

1970 ◽  
Vol 28 ◽  
pp. 208-209
Author(s):  
K.K. SEKHRI ◽  
C.S. ALEXANDER ◽  
H.T. NAGASAWA
Keyword(s):  
Osmium Tetroxide ◽  
Male Mice ◽  
Alcohol Group ◽  
Group Iii ◽  
Group I ◽  
C57bl Mice ◽  
Group Ii

C57BL male mice (Jackson Lab., Bar Harbor, Maine) weighing about 18 gms were randomly divided into three groups: group I was fed sweetened liquid alcohol diet (modified Schenkl) in which 36% of the calories were derived from alcohol; group II was maintained on a similar diet but alcohol was isocalorically substituted by sucrose; group III was fed regular mouse chow ad lib for five months. Liver and heart tissues were fixed in 2.5% cacodylate buffered glutaraldehyde, post-fixed in 2% osmium tetroxide and embedded in Epon-araldite.

The Quantitative Ultrastructure of the Heart Muscle of Japanese Quail by Hypergravitation, Hypodynamy and Combination

1990 ◽  
Vol 48 (3) ◽  
pp. 188-189
Author(s):  
Anton Bózner ◽  
Mikuláš Gažo ◽  
Jozef Dostál
Keyword(s):  
Japanese Quail ◽  
Heart Muscle ◽  
Relative Size ◽  
Combination Group ◽  
Control Group ◽  
Group V ◽  
Group Iii ◽  
Space Flights ◽  
Group I ◽  
Quantitative Ultrastructure

It is anticipated that Japanese quail /Coturnix coturnix japonica/ will provide animal proteins in long term space flights. Consequently this species of birds is of research interest of international space program INTERCOSMOS. In the year 1987 we reported on an experiment /2/ in which the effect of chronic acceleration of 2 G hypergravitation, the hypodynamy and the simultaneous effect of chronic acceleration and the location in the centre of the turntable of the centrifuge on the protein fractions in skeletal muscles was studied. The ultrastructure of the heart muscle was now in this experiments examined as well.Japanese quail cockerels, aged 48 days were exposed to 2 G hypergravitation /group IV/ in a 6,4 m diameter centrifuge, to hypodynamy /group III/ and their combination /group V/, respectively for 6 days / Fig.1/. The hypodynamy in group III was achieved by suspending the birds in jackets without contact the floor. The group II was located in the centre ofthe turntable of the centrifuge. The control group I. was kept under normal conditions. The quantitative ultrastructure of myocard was evaluated by the methods of Weibel/3/ - this enables to determine the number, relative size and volume of mitochondria volume of single mitochondria, defficiency of mitochondrial cristae and volume of myofibrils.

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