4 research outputs found
INCAS SUBSONIC WIND TUNNEL
The INCAS Subsonic Wind Tunnel is a closed circuit, continuous, atmospheric pressure facility with a maximum speed of 110 m/s. The test section is octagonal ,of 2.5 m wide, 2.0 m high and 4 m long. The tunnel is powered by a 1200 kW, air cooled variable speed DC motor which drives a 12 blade, 3.5 m diameter fan and is equipped with a six component pyramidal type external mechanical balance with a 700 Kgf maximum lift capacity.The angle of attack range is between -45º and +45º while the yaw angle range is between -140º and +216º .The data acquisition system has been modified recently to allow the recording of all test data on a PC - type computer using LABVIEW and a PXI – type chassis containing specialized data acquisition modules.The tunnel is equipped with a variable frequency electrical supply system for powered models and a 10 bar compressed air supply for pneumatic flow control applications.In the recent years the subsonic wind tunnel has been intensively used for tests within several European projects (AVERT, CESAR and others)
The nuclei of the hypothalamus in cow
As a research material we have used the hypothalamo-hypophyseal complexes
of 21 cows in the phases of their sexual cycle. From the 21 samples, we have obtained only ten
hypothalamico-hypophyseal complexes; in 11 females, the hypothalamus has been obtained
separately from the hypophysis, because of the difficulty in getting the complex of the whole.
The samples have been fixed in Orth, Carnoy and Helly, led up to paraffin and serially
sectioned at 5 ÎĽm. We have finally obtained 550 serial sections, stained through the methods
Novelli, PAS, Fontana, Steedman-Mowry, Mikami, Bielschowsky, Bodian, Holmes and Nissl.
In the cow hypothalamus, we have found the following groups of neurons: anterior (nucleus
supraopticus – NSO; nucleus paraventricularis – NPV), middle (nucleus infundibularis),
lateral (nucleus hypothalamicus dorsomedialis; nucleus hypotalamicus ventromedialis) and
posterior (nucleus periventricularis caudalis; nucleus premamilaris; nucleus corporis
mamilaris). The name of the groups was given according to their site, compared to the
hypothalamo-neurohypophyseal tract. In the walls of the third hypothalamus ventricle in cow
the neurons were localized, which elaborated the releasing hormones (RH) for the
gonadotrophic hormones. These neurons have structured the nucleus infundibularis of the cow
hypothalamus. The neurons were multipolar, with an average size of 10-12 ÎĽm, a 5 ÎĽm large
vesiculous nucleus and nucleolated. In the neuroplasm of the axon hillock, we have found the
numerous PAS-positive granules. These granules were positive in Mikami staining, got stained
in blue, which demonstrated that they were of polypeptidic nature. FSH-RH and LH-RH are
polypeptids and stimulated the secretions of the gonadotrophic hormones in the β-FSH and the
Îł-LH cells from the cow adenohypophysis
The follicular structures in the intermediary lobe of the bull hypophysis
As a research material we have used the hypophyses of 14 Holstein bulls aged
of 3-8 years. The samples have been fixed in Orth, Carnoy, and Helly, led up to paraffin, and
serially sectioned at 5 ÎĽm. We have finally obtained 420 serial sections stained through the
methods Novelli, PAS, Papanicolau, MH2, Fontana, Steedman-Mowry, Bielschowsky, Bodian
and Holmes. The intermediary lobe is well developed in the bull. It is always adjacent to the
posterior lobe of the bull hypophysis, and separated from it by a discontinuous layer of
conjunctive tissue. The follicular structures (110-360 ÎĽm), containing colloid in the lumen,
were found in the intermediary lobe of 14 bull hypophysis. A thin conjunctive tissue separated
these follicular structures. They formed cysts, which contained colloid. The colloid is a palestaining
material, PAS-positive, and is surrounded by simple squamous or cubical epithelium.
The colloid consists in a glycoprotein in the Steedman-Mowry stain. The intermediary lobe of
the hypophysis makes a hormone MSH (Melanocyte Stimulating Hormone), which is
responsible for the expansion of melanocytes from the animals’ skin