Density functional theory (DFT) calculations were performed to compute nitrogen-14 and boron-11 nuclear quadrupole resonance (NQR) spectroscopy parameters in the representative model of armchair boron nitride nanotube (BNNT) for the first time. The considered model consisting of 1 nm length of H-capped (5, 5) single-wall BNNT were first allowed to fully relax and then the NQR calculations were ...

Carbon can form numerous allotropes because of its valency. Graphene, carbon nanotubes,capped carbon nanotubes, buckyballs, and nanocones are well-known polymorphs of carbon.Remarkable mechanical properties of these carbon atoms have made them the subject of intenseresearch. Several studies have been conducted on carbon nanotubes or graphene. In the presentstudy, the molecular mechanics method ...

We introduce and describe the topology of a family of complete immersed manifolds in R N ; having a nice behaviour at innnity, which we call conical type end manifolds. Our main result states that a complete, non compact immersed manifold in R N ; whose lim sup of the norm of the second fundamental form times the intrinsic distance of the manifold to a xed point is strictly less than 1, as the ...

Synthetic nerve guidance channels are used to better understand the cellular and molecular events controlling peripheral nerve regeneration. In the present study, the contribution of wound-healing molecules to peripheral nerve regeneration was assessed by varying the molecular weight cutoff of the tubular membrane. Nerve regeneration through polysulfone tubular membranes with molecular weight (...

Abstract Minimizing the entropy generation rate is one of key performance indicators for enhancing thermal design heat exchangers. This paper introduces a comprehensive numerical analysis turbulent water flow inside—newly proposed—conical tubes with dimples subjected to constant flux. The effect different tube diameter ratios (DR = 1, 1.5, 2, 3, and 5) modes (convergent divergent configurations...

Conical diffusers of various configurations are used in many kinds technical equipment and manufacturing processes. Therefore, it is a relevant objective to obtain reliable experimental mathematical data on the aerodynamic characteristics diffusers. This article presents aerodynamics stationary flows vertical conical diffuser when air supplied through tubes with cross sections (circle, square, ...

I t was with great interest that I read the review by J. Brodsky and M.Lemmens on “The history of anesthesia for thoracic surgery”.1 The authors must be credited for presenting physiologically well-founded facts and for providing rare contemporary photographic material. They must also be recognized for discussing clinically deplorable and ill-advised methods of tackling the issue of gas exchang...

against good medical practice to continue to use a ‘standard cuff ed tube’ given the weight of evidence supporting the use of newer tube designs to prevent ventilator-associated pneumonia (VAP). Th ere is strong evidence supporting the use of subglottic aspiration to prevent VAP [2]. However, other new tracheal tubes, such as polyurethane cuff ed, silver-coated, or low-volume low-pressure tubes...

abstract   background: iatrogenic airway injury after endotracheal intubation and tracheotomy remains a serious clinical problem. in this study we reviewed post-intubation and traumatic tracheal stenosis in 47 patients with a special attention to the cause, hense surgical treatment of the stenosis was performed and the results compared with the literatures.   methods: since february 1995 throug...