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 $M\times\mathbb{R}$, where $M$ 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

Entropy production in boundary layers

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77333/1/AIAA-197-774.pd

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

Resonance Raman Scattering in TlGaSe 2

The resonance Raman scattering for geometries Y(YX)Z and Y(ZX)Z at temperature 10 K and infrared reflection spectra in E∥a and E∥b polarizations at 300 K were investigated. The number of Aa (Ba) and Au (Bu) symmetry vibrational modes observed experimentally and calculated theoretically agree better in this case than when TlGa2Se4 crystals belong to D2h symmetry group. The emission of resonance Raman scattering and excitonic levels luminescence spectra overlap. The lines in resonance Raman spectra were identified as a combination of optical phonons in Brillouin zone center

A comparison of filtration rates among pelagic tunicates using kinematic measurements

Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Marine Biology 157 (2010): 755-764, doi:10.1007/s00227-009-1359-y.Salps have higher filtration rates than most other holoplankton, and are capable of packaging and exporting primary production from surface waters. A method of kinematic analysis was employed to accurately measure salp feeding rates. The data were then used to explain how diverse body morphologies and swimming motions among species and lifecycle stages influence salp feeding performance. We selected five species, representing a range of morphologies and swimming styles, and used digitized outlines from video frames to measure body-shape change during a pulse cycle. Time-varying body volume was then calculated from the digitized salp outlines to estimate the amount of fluid passing through the filtering mesh. This non-invasive method produced higher feeding rates than other methods and revealed that body volume, pulse frequency and degree of contraction are important factors for determining volume filtered. Each species possessed a unique combination of these three characteristics that resulted in comparable filtration (range: 0.44 - 15.33 ml s-1) and normalized filtration rates (range: 0.21 – 1.27 s-1) across species. The convergence of different species with diverse morphologies on similar normalized filtration suggests a tendency towards a flow optimum.This work was supported by NSF project OCE-0647723

Natural Diagonal Riemannian Almost Product and Para-Hermitian Cotangent Bundles

We obtain the natural diagonal almost product and locally product structures on the total space of the cotangent bundle of a Riemannian manifold. We find the Riemannian almost product (locally product) and the (almost) para-Hermitian cotangent bundles of natural diagonal lift type. We prove the characterization theorem for the natural diagonal (almost) para-K\"ahlerian structures on the total spaces of the cotangent bundle.Comment: 10 pages, will appear in Czechoslovak Mathematical Journa

HD Diesel engine equipped with a bottoming Rankine cycle as a waste heat recovery system. Part 2: Evaluation of alternative solutions

A theoretical investigation has been performed on the feasibility of introducing a waste heat recovery (WHR) system in a two-stage turbocharged HDD engine. The WHR is attained by introducing a Rankine cycle, which uses an organic substance or directly water as a working fluid depending on energetic performance considerations. A previous research was carried out to evaluate the maximum potential of this WHR concept, a conventional layout was used for coupling the Rankine cycle to the thermal engine. The objective of the present research is to broad the scope of the previous analysis by considering new alternative solutions for the problems related to the coupling between the WHR Rankine cycle and the thermal engine. These solutions are based on adapting one of the turbochargers by removing its turbine and trying to recover the energy by the Rankine cycle. Finally, the turbine of the Rankine cycle supplies the recovered energy directly to the compressor of this turbocharger. Thus, in these layouts the coupling is simpler as it involves only two turbomachines, which are supposed to share a similar rotating speed. From the results of the global energy balance, these alternative layouts produce slight benefits in fuel consumption but in all cases these benefits are lower compared to those attained with conventional layouts. © 2011 Published by Elsevier Ltd. All rights reserved.This work was partially funded by "Programa de Apoyo a la Investigacion y Desarrollo de la Universidad Politecnica de Valencia".Serrano Cruz, JR.; Dolz Ruiz, V.; Novella Rosa, R.; García Martínez, A. (2012). HD Diesel engine equipped with a bottoming Rankine cycle as a waste heat recovery system. Part 2: Evaluation of alternative solutions. Applied Thermal Engineering. 36:279-287. doi:10.1016/j.applthermaleng.2011.10.024S2792873