a series of subsonic wind tunnel tests was conducted on an ogive-cylinder-flare configuration at zero angle of attack to study the effects of small helical protuberances on viscous drag reduction behavior. the experiments have been carried out on a smooth model and two wire-wrapped models with different spacing between the helical riblet rings, known as pitch length. in the present experiments,...

Astrocytes play an important role in regulating neuronal activity and local brain states, in part by serving as intermediaries between neurons and vasculature. We postulate that neurons and astrocytes are sensitive to biophysical conditions in their local environment, in addition to their participation in traditional signaling networks with other neurons. Mechanically sensitive astrocytic endfe...

carbon spheres were fabricated by hydrothermal method and their structural properties were investigated. carbon spheres with average sizes around of 230, 320 and 430 nm were synthesized in different concentration of glucose aqueous solution and different hydrothermal reaction time. the temperature of 180 °c by a hydrothermal reaction was fixed in all of glucose concentration and hydrothermal re...

the average distance of a vertex $v$ of a connected graph $g$is the arithmetic mean of the distances from $v$ to allother vertices of $g$. the proximity $pi(g)$ and the remoteness $rho(g)$of $g$ are defined as the minimum and maximum averagedistance of the vertices of $g$. in this paper we investigate the difference between proximity or remoteness and the classical distanceparameters diameter a...

The diameter of a connected graph $G$, denoted by $diam(G)$, is the maximum distance between any pair of vertices of $G$. Let $L(G)$ be the line graph of $G$. We establish necessary and sufficient conditions under which for a given integer $k geq 2$, $diam(L(G)) leq k$.

We investigated the local and remote vascular changes evoked by activation of the cerebellar parallel fibers (PFs). The PFs were stimulated (25-150 microA, 30 Hz) in halothane-anesthetized rats equipped with a cranial window. The changes in arteriolar and venular diameter produced by PF stimulation were measured with the use of a videomicroscopy system. Cerebellar blood flow (BFcrb) was monitor...

PURPOSE To determine the maximum tolerated dose of single fraction radiosurgery in patients with recurrent previously irradiated primary brain tumors and brain metastases. METHODS AND MATERIALS Adults with cerebral or cerebellar solitary non-brainstem tumors </= 40 mm in maximum diameter were eligible. Initial radiosurgical doses were 18 Gy for tumors </= 20 mm, 15 Gy for those 21-30 mm, and ...

A minimum spanning tree (MST) with a small diameter is required in numerous practical situations. It is needed, for example, in distributed mutual exclusion algorithms in order to minimize the number of messages communicated among processors per critical section. Understanding the behavior of tree diameter is useful, for example, in determining an upper bound on the expected number of links bet...

Let G be an edge weighted undirected graph. For every pair of nodes consider the shortest cycle containing these nodes in G. The cycle diameter of G is the maximum length of a cycle in this set. Let H be a directed graph obtained by directing the edges of G. The cycle diameter of H is similarly defined except for that cycles are replaced by directed closed walks. Is there always an orientation ...