Search results for "Lift"
showing 10 items of 217 documents
THE CAUCHY DUAL AND 2-ISOMETRIC LIFTINGS OF CONCAVE OPERATORS
2018
We present some 2-isometric lifting and extension results for Hilbert space concave operators. For a special class of concave operators we study their Cauchy dual operators and discuss conditions under which these operators are subnormal. In particular, the quasinormality of compressions of such operators is studied.
Cultivation of granular sludge with hypersaline oily wastewater
2015
The time required to stabilise mature aerobic granules is rather variable. In addition, cultivation time and the structural characteristics of granules seem to be related to the nature of wastewater influent. Granular sludge has been used for the treatment of several industrial wastewaters, but nothing has been reported about wastewater characterized by the simultaneous presence of hydrocarbons and high chloride concentration. In this work, the authors analysed the granulation process and performance as well as the physical characteristics of aerobic granules in two Granular Sequencing Batch Airlift Reactors (GSBARs), fed with acetate-based synthetic wastewater in reactor 1 (R1) and with a …
Influence of heterogeneous freezing on the microphysical and radiative properties of orographic cirrus clouds
2013
The influence of heterogeneous freezing on the microphysical and optical properties of orographic cirrus clouds has been simulated with the large eddy simulation model EULAG. Idealised simulations with different concentrations of ice nuclei (IN) in a dynamically dominated regime with high vertical velocities have been performed. Furthermore the temperature at cloud formation as well as the critical supersaturation for initiation of heterogenous freezing have been varied. The shortwave, longwave and net cloud forcing has been calculated under the assumption that the clouds form between 06:00 and 12:00 local time (LT) or between 12:00 and 18:00 LT. In general it can be seen that the onset of …
Cyclic and lift closures for k…21-avoiding permutations
2011
We prove that the cyclic closure of the permutation class avoiding the pattern k(k-1)...21 is finitely based. The minimal length of a minimal permutation is 2k-1 and these basis permutations are enumerated by (2k-1).c"k where c"k is the kth Catalan number. We also define lift operations and give similar results. Finally, we consider the toric closure of a class and we propose some open problems.
Lifting paths on quotient spaces
2009
Abstract Let X be a compactum and G an upper semi-continuous decomposition of X such that each element of G is the continuous image of an ordered compactum. If the quotient space X / G is the continuous image of an ordered compactum, under what conditions is X also the continuous image of an ordered compactum? Examples around the (non-metric) Hahn–Mazurkiewicz Theorem show that one must place severe conditions on G if one wishes to obtain positive results. We prove that the compactum X is the image of an ordered compactum when each g ∈ G has 0-dimensional boundary. We also consider the case when G has only countably many non-degenerate elements. These results extend earlier work of the firs…
The number of lifts of a Brauer character with a normal vertex
2011
AbstractIn this paper we examine the behavior of lifts of Brauer characters in p-solvable groups. In the main result, we show that if φ∈IBr(G) has a normal vertex Q and either p is odd or Q is abelian, then the number of lifts of φ is at most |Q:Q′|. As a corollary, we prove that if φ∈IBr(G) has an abelian vertex subgroup Q, then the number of lifts of φ in Irr(G) is at most |Q|.
Numerical and experimental analysis of a high innovative hydrofoil
2020
The hydrofoil is a craft where the weight is entirely supported by the lift generated by the submerged part of wings. The particular structure of the craft requires a thorough study of the architecture of the hull, whose structure differs from others high speed vessels since the lift on wing surfaces are transmitted to the hull in limited areas (wing attacks). The authors have developed a research to optimize geometry of hull and wing system on a hydrofoil capable to carry 250 passengers at a speed of 35 knots, operating among Sicilian island. The principal goals of the new hydrofoil concern both the fuel reduction that the improvement of the comfort in terms of seakeeping and levels of aco…
Effect of amount of biomaterial used for maxillary sinus lift on volume maintenance of grafts
2020
Background Regardless of the kind of biomaterial used for the graft, it is clear that, over time, the graft undergoes dimensional changes that could influence the final bone volume obtained, which could alter the stability of the installed implants. The aim of the present study was to compared and correlated the graft behavior with the amount (in grams) of xenogeneic and alloplastic biomaterials used in grafts for maxillary sinus lift. Material and Methods This retrospective cohort study used 148 CBCT images of 74 grafts from 68 maxillary sinuses lift patients in a university, post-graduate clinic. The weights of biomaterials, categorized in intervals according to amount used, were correlat…
What is the frequency of anatomical variations and pathological findings in maxillary sinuses among patients subjected to maxillofacial cone beam com…
2016
Background When considering dental implant rehabilitation in atrophic posterior sectors, the maxillary sinuses must be evaluated in detail. Knowledge of the anatomical variations and of the potential lesions found in these structures conditions the outcome of sinus lift procedures and therefore of the dental implants. A systematic review is made to determine the frequency of anatomical variations and pathological findings in maxillary sinuses among patients subjected to cone beam computed tomography (CBCT). Material and Methods A PubMed (MEDLINE) literature search was made of articles published up until 20 December 2015. The systematic review was conducted based on the Preferred Reporting I…
An experimental investigation on two different methods for swirl induction in a multivalve engine
2005
This paper describes an experimental investigation aimed at comparing the swirl effect induced by unbalancing the mass flow through the two intake ports of a multivalve engine head using two different methods: the first one reduced the curtain area of one of the intake valves [different lifts (DL) method]; the second one adopted a sluice-gate-shaped valve, installed upstream of the intake valves [swirl control valve (SCV) method] in order to cause a pressure drop. A steady-flow test rig (equipped with instrumentation for the discharge coefficient and swirl intensity measurement) was realized in order to compare and evaluate the results of both methods and determine their respective validit…