725 research outputs found
Ampelographic characterization - preliminary results of the nine most appreciated autochthonous Vitis vinifera L. varieties from Romania
The paper presents an up-to-date description of some autochthonous, old and valuable grapevine varieties maintained within the germplasm collection belonging to the University of Agronomical Science and Veterinary Medicine Bucharest, respectively 3 varieties for red wines ('Fetească neagră', 'Băbească neagră', ‚Busuioacă de Bohotin') and 6 varieties for white wines ('Fetească albă', 'Fetească regală', 'Galbenă de Odobeşti', 'Grasă de Cotnari', 'Tămâioasă românească' and 'Zghihară de Huşi'). The results obtained by applying standardized methodology for grape quantitative and qualitative parameters for three consecutive years, reveal the main characteristics for each variety and also the specific genotype response to particular pedoclimatic conditions. In comparison to 'Cabernet Sauvignon' as reference cultivar, 'Băbească neagră' and 'Busuioacă de Bohotin' varieties were characterized by higher values for the sizes and weights of the berries, and 'Fetească neagră' by heavier bunches and higher sugar juice content. The white grape varieties in comparison to 'Chardonnay' as reference cultivar, were remarked either by bigger bunches with high to very high sugar content ('Fetească regală', 'Grasă de Cotnari', 'Tămâioasă românească'), or by constancy of bunch weight and titratable acidity of must ('Fetească albă', 'Galbenă de Odobeşti' and 'Zghihară de Huşi')
Constructal blade shape in nanofluids
Blade configuration of nanofluids has been proven to perform much better than dispersed configuration for some heat conduction systems. The analytical analysis and numerical calculation are made for the cylinder--shaped and regular-rectangular-prism--shaped building blocks of the blade-configured heat conduction systems (using nanofluids as the heat conduction media) to find the optimal cross-sectional shape for the nanoparticle blade under the same composing materials, composition ratio, volumetric heat generation rate, and total building block volume. The regular-triangular-prism--shaped blade has been proven to perform better than all the other three kinds of blades, namely, the regular-rectangular-prism--shaped blade, the regular-hexagonal-prism--shaped blade, and the cylinder--shaped blade. Thus, the regular-triangular-prism--shaped blade is selected as the optimally shaped blade for the two kinds of building blocks that are considered in this study. It is also proven that the constructal cylinder--regular-triangular-prism building block performs better than the constructal regular-rectangular-prism--regular-triangular-prism building block
Role of transport performance on neuron cell morphology
The compartmental model is a basic tool for studying signal propagation in
neurons, and, if the model parameters are adequately defined, it can also be of
help in the study of electrical or fluid transport. Here we show that the input
resistance, in different networks which simulate the passive properties of
neurons, is the result of an interplay between the relevant conductances,
morphology and size. These results suggest that neurons must grow in such a way
that facilitates the current flow. We propose that power consumption is an
important factor by which neurons attain their final morphological appearance.Comment: 9 pages with 3 figures, submitted to Neuroscience Letter
Rootstocks and wild grapevines responses to salinity
A study of the effects induced by salt solutions applied on in vitro cultures and potted vines comparing five widely used rootstocks in Romania and six wild accessions from five populations of Vitis vinifera L. ssp. sylvestris (Gmelin) Hegi was performed. For in vitro test, all genotypes were analyzed for toxicity symptoms appearance in media containing 17, 32 and 49 mM NaCl. The same accessions, as potted plants, were subjected to salt treatments with 51, 68 and 102 mM NaCl, and were evaluated in terms of growth reduction and toxicity symptoms emergence after one month of salt treatment. P, K and Na contents were detected in in vitro plantlets and potted plants. Results showed significant differences among genotypes and between the in vitro and potted treatments. The wild grapevine individuals, in comparison to the rootstocks, expressed a higher ability to adapt to the salt stress in both type of treatments. In comparison with the rootstocks, the wild grapevine individuals were characterized by a higher content of P and lower contents of K and Na, which could be directly correlated with their ability to uptake and accumulate a higher level of Na and Cl into their tissues
Effect of width and temperature of a vertical parallel plate channel on the transition of the developing thermal boundary layer
Numerical simulations are performed to study the transition of the development of the thermal boundary layer of air along an isothermal heated plate in a large channel which is bounded by an adiabatic plate. In particular, the aim is to investigate the effects of the channel width (b) on the transition of the flow under various plate temperatures. Three different RANS based turbulent k–ε models namely standard, RNG and Realizable with an enhanced wall function are employed in the simulations. The channel width was varied from 0.04 m to 0.45 m and the numerical results of the maximum values of the flow velocity, turbulent kinetic energy were recorded along the vertical axis to examine the critical distance of the developing flow. The results show that the transition delays when the width is increased from 0.04 m to 0.08 m and particularly, the critical distance at b = 0.08 m reaches its maximum with the Grashof number of 2.8 × 1010. However, the critical distance drops when b is increased further from 0.08 m to 0.45 m, indicating an early transition of the flow. The transition remains unaffected by the adiabatic plate when b is greater than 0.45 m. Comparisons of selected numerical results are made with available experimental data of turbulent flow and a satisfied agreement is received
Some constructions of almost para-hyperhermitian structures on manifolds and tangent bundles
In this paper we give some examples of almost para-hyperhermitian structures
on the tangent bundle of an almost product manifold, on the product manifold
, where is a manifold endowed with a mixed 3-structure
and on the circle bundle over a manifold with a mixed 3-structure.Comment: 10 pages; This paper has been presented in the "4th German-Romanian
Seminar on Geometry" Dortmund, Germany, 15-18 July 200
OPTIMALLY STAGGERED FINNED CIRCULAR AND ELLIPTIC TUBES IN FORCED CONVECTION
This work presents a three-dimensional (3-D) numerical and experimental geometric
optimization study to maximize the total heat transfer rate between a bundle of finned
tubes in a given volume and a given external flow both for circular and elliptic
arrangements, for general staggered configurations. The optimization procedure started
by recognizing the design limited space availability as a fixed volume constraint. The
experimental results were obtained for circular and elliptic configurations with a fixed
number of tubes (12), starting with an equilateral triangle configuration, which fitted
uniformly into the fixed volume with a resulting maximum dimensionless tube-to-tube
spacing S/2b = 1.5, where S is the actual spacing and b is the smaller ellipse semi-axis.
Several experimental configurations were built by reducing the tube-to-tube spacings,
identifying the optimal spacing for maximum heat transfer. Similarly, it was possible to
investigate the existence of optima with respect to other two geometric degrees of
freedom, i.e., tube eccentricity and fin-to-fin spacing. The results are reported for air as
the external fluid in the laminar regime, for 125 and 100 Re 2b , where 2b is the
ellipses smaller axis length. Circular and elliptic arrangements with the same flow
obstruction cross-sectional area were compared on the basis of maximum total heat
transfer. This criterion allows one to quantify the heat transfer gain in the most isolated
way possible, by studying arrangements with equivalent total pressure drops
independently of the tube cross section shape. This paper reports three-dimensional (3-
D) numerical optimization results for finned circular and elliptic tubes arrangements,
which are validated by direct comparison with experimental measurements with good
agreement. Global optima with respect to tube-to-tube spacing, eccentricity and fin-tofin
spacing ( 0.5 e 0.5, S/2b and 06 . 0 f for 125 and 100 Re 2b ,
respectively) were found and reported in general dimensionless variables. A relative heat
transfer gain of up to 19% is observed in the optimal elliptic arrangement, as compared
to the optimal circular one. The heat transfer gain, combined with the relative material
mass reduction of up to 32% observed in the optimal elliptic arrangement in comparison
to the circular one, show the elliptical arrangement has the potential for a considerably
better overall performance and lower cost than the traditional circular geometry
Microsurgery in the treatment of local advanced laryngeal cancer
IMSP Institutul Oncologic, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Anual în Republica Moldova sunt depistați circa 150 pacienți cu cancer localizat în zon larinofaringiană. În majoritatea cazurilor clinice procesului este
local avansat, ce necesită un tratament combinat, complex şi o reabilitare chirurgicală amplă. Pe lîngă metodele tradiționale de reabilitare chirurgicală,
în secția tumorilor capului şi gâtului din luna mai 1989 a fost implimentată metoda microchirurgicală de reabilitare a pacienților. În perioada 1989
până în prezent după această metodă au fost tratați circa 150 pacienți, 66 din ei au fost tratați pentru cancer local avansat al zonei laringofaringiene.
Toți pacienții au fost supuşi tratamentului radioterapic pre- sau/şi postoperator, în volum 40 – 66 Gr. În toate cazurile au fost efectuate laringectomii
cu formare de faringoesofagostomie planică. Toți pacienții au fost supuşi intervenției chirurgicale la căile limfatice cervicale.Primul grup – lambourile
utilizate pentru formarea tunicii interne a traiectului faringoesofagian. Lambouri libere: 1. cutanofasciale: radial 10 cazuri; scapular 10 cazuri; 2. viscerale: jejunal 7 cazuri; stomac- epiplon 4 cazuri. Al doilea grup: lambourile utilizate pentru formarea tunicii externe a traiectului faringoesofagian. Lambouri libere: 1. cutanomusculare: TDL 22 cazuri; TFL 1 caz; TDL + SL 2 cazuri. Complicațiile postoperatorii au fost cauzate de dereglări în microcirculația lamboului şi anastomozei vasculare. În 40% cazuri dereglările de microcirculație s-au manifestat prin declanşarea necrozei parțiale a lamboului şi
apariția fistulei faringo-esofagiene. Într-un caz a fost constatată necroza totală a lamboului. Durata perioadei de reabilitare a pacienților cu restabilirea totală a traiectului faringo-esofagian a constituit în mediu 25 zile.Each year, in Moldova, about 150 pacients are being traced, having laryngopharyngeal cancer. In most cases, the process is in advanced stage, needing
a combined and complex treatment, with a large surgical rehabilitation. Besides the traditional methods, the Departement of Head and Neck Tumors,
since May 1989, has implemented the microsurgical method of rehabilitation. Beginning with 1989 until present, with the help of this method, about
150 patients have been treated, 66 of them having local advanced laryngopharyngeal cancer.All patients have passed radiotherapy, either before the
surgical intervention, after it or both, in terms of 40-66 Gr. Laryngectomy with planned pharyngoesophagostomy has been performed in every case. All
patients have passed surgical intervention on lymphatic cervical canals. First group – the flaps used for forming the internal tunic of pharyngoesophageal
path.Free flaps:1)cutanofascial: radial – 10 cases, scapular – 10 cases;2)visceral: jejunal – 7 cases; stomach-omentum – 4 cases;Second group – the flaps
used for forming the external tunic of pharyngoesophageal path.Free flaps:1)cutanomuscular: TDL – 22 cases, TFL – 1 case, TDL+SL – 2 cases.The
after-surgical complications have been caused by disorders, appeared in the microcirculation of the flap and the vascular anastomosis. In 40% of all
cases, the microcirculation disorders have been displayed by triggering the partial necrosis of the flap and by the appearance of pharyngoesophageal
fistula. In one case, there has been observed a total necrosis of the flap.The period of rehabilitation, with total recovery of the pharyngoesophageal
path, has lasted an average of 25 days
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