3,520 research outputs found
Radiation Resistant Silicon Semiconductor Devices-Patent
Improving radiation resistance of silicon semiconductor junctions by doping with lithiu
Simplified method introduces drift fields into cells
Drift fields are simply introduced into solar cells at low temperatures in short periods. This is done after their rectifying junctions and output contacts are applied
Foliated Lie systems: Theory and applications
A - foliated Lie system is a first-order system of ordinary
differential equations whose particular solutions are contained in the leaves
of the foliation and all particular solutions within any leaf can
be written as a certain function, a so-called foliated superposition rule, of a
family of particular solutions of the system within the same leaf and several
parameters. We analyse the properties of such systems and we illustrate our
results by studying Lax pairs and a class of -dependent Hamiltonian systems.
We finally study foliated Lie systems through Poisson structures and
-matrices.Comment: 24 page
Error Performance of the 13-Channel DS CDMA WATM LAN
In the paper, we present simulation results for the 13 channel DS CDMA WATM LAN utilising optimized complex spreading signatures based on Walsh-Rademacher functions. The method to obtain those optimized spreading signatures, as well as the full set of the coefficients giving the minimum level of cross-correlation between any pair of the channels is shown. The resultant system BER and the distribution of errors within encapsulated WATM cells is given. The obtained results indicate that with the application of a hybrid ARQ scheme, capable of correcting 10 errors, the number of WATM cells which would require retransmission is in the order of I-2%
The size of venous foramina and skull capacity in man and selected vertebrate species
In many experiments it was proved that brain cooling systems in mammals and
birds depend on the flow of the cool venous blood into the cranial cavity through
a well-developed system of foramina. In order to investigate the anatomical
basis of this mechanism a morphological study was undertaken. On 10 species
of mammals and birds, a correlation between the skull capacity and the size of
its main venous foramina was determined. A computer system of image analysis
was used. In man the skull that was the largest, however consisted venous
foramina of the smallest size. Moreover, the asymmetry of the foramina and
the concentration of the outflow in one dominant foramen was the greatest.
Probably the dominance of only one venous foramen on each side of the human
skull provides the reduction of flow resistance and creates more advantageous
conditions for blood outflow from the skull, and therefore, better conditions
for brain cooling. (Folia Morphol 2008; 67: 98–103
Topographical anatomy and morphometry of the temporal bone of the macaque
Based on the dissections of 24 bones of 12 macaques (Macaca mulatta),
a systematic anatomical description was made and measurements of the chosen
size parameters of the temporal bone as well as the skull were taken.
Although there is a small mastoid process, the general arrangement of the
macaque’s temporal bone structures is very close to that which is observed in
humans. The main differences are a different model of pneumatisation and
the presence of subarcuate fossa, which possesses considerable dimensions.
The main air space in the middle ear is the mesotympanum, but there are also
additional air cells: the epitympanic recess containing the head of malleus
and body of incus, the mastoid cavity, and several air spaces on the floor of
the tympanic cavity. The vicinity of the carotid canal is also very well pneumatised
and the walls of the canal are very thin. The semicircular canals are
relatively small, very regular in shape, and characterized by almost the same
dimensions. The bony walls of the labyrinth are relatively thin
Topographical anatomy and measurements of selected parameters of the rat temporal bone
On the basis of dissection of 24 bones of 12 black rats a systematic anatomical
description was made and measurements of selected size parameters of the temporal
bone were taken. Besides the main air space in the middle ear, the tympanic
bulla, there are also additional air cells, namely the anterior and posterior
epitympanic recesses, containing the head of the malleus and the body of the
incus. On the side of the epitympanic recesses the following are easily accessible:
the malleus head and the core of the incus, the superior and lateral semicircular
canals and the facial nerve. On the side of the ventral tympanic bulla it is
easy access to both windows and the cochlea. The semicircular canals are relatively
large, the lateral canal being the largest and the posterior the smallest. The
length of the spiral canal of the cochlea does not exceed 11 mm. It is worth
mentioning that both the vertical and horizontal dimensions of the scala vestibuli
and scala tympani do not even exceed 0.7 mm in the basal turn, and are significantly
decreased to tenths of a millimetre in further turns. This needs to be taken
into consideration during all experiments requiring the introduction of examining
instruments into the cochlear scala. (Folia Morphol 2008; 67: 111–119
A Method to Partially Suppress IS1 and MA1 for DS SS CDMA Wireless Networks
We propose a method to partially suppress ISI and MAI for US SS CDMA schemes in wireless LANs. The method can be regarded as an alternative approach to combat ISI and in particular MAI by the use of advanced multiuser detection. Instead of using very sophisticated detectors, we propose introduction of a simple modification to the carrier waveform which results in very substaiitial reduction in cross-correlation belween users and an off-peak auto-correlation. The method can be applied to any DS SS CDMA scheme, but should be particularly useful in the case of short spreading signatures, as is the case of WLAN
Radiation damage in silicon first semiannual report, oct. 15, 1963 - apr. 15, 1964
Observed paramagnetic center, effects of impurities on radiation damage of silicon, and low energy proton bombardment of silicon and gallium arsenide solar cell
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