the study of flight vehicle structures reveals the importance of obtaining the most suitable accuracy compatible with construction. for this purpose, several experiments were conducted at the agard institute. in this paper the results of one such experiment performed on a sample airplane wing are presented. aircraft structural engineers use several methods to model these structures. specifing h...

This study describes the initial phases of wing morphogenesis of Megoura viciae Buckton (Homoptera Aphididae). We evaluated the development of wing buds in males (winged) and parthenogenetic females (presumed to become wingless) of M. viciae from birth to 4 instar. Wing bud epithelium in males is initially simple, becoming bistratified and then progressing to stratify. Mitotic activity is more ...

A multi-objective optimization (MOO) of two-element wing models with morphing flap by using computational fluid dynamics (CFD) techniques, artificial neural networks (ANN), and non-dominated sorting genetic algorithms (NSGA II), is performed in this paper. At first, the domain is solved numerically in various two-element wing models with morphing flap using CFD techniques and lift (L) and drag ...

The heat-induced conversion of 5-methylcytosine (m5C) residues to thymine residues and of cytosine to uracil residues in single-stranded DNA was studied. The calculated rates for deamination at 37 degrees C and pH 7.4 were approximately 9.5 X 10(-10) and 2.1 X 10(-10) sec-1, respectively. N4-Methyldeoxycytidine, which is in the DNA of certain thermophilic bacteria, was more heat-resistant than ...

This paper describes a range of theoretical studies into the likely properties of poly-nitrogen molecules (Nn, n>3). In particular, we describe the approach we have used to assess the potential detonation performance of this class of material, and illustrate this with a number of example calculations. We also discuss the implications and limitations of these predictions. In addition, we describ...

Given a Euclidean graph G in Rd with n vertices and m edges, we consider the problem of adding an edge to G such that the stretch factor of the resulting graph is minimized. Currently, the fastest algorithm for computing the stretch factor of a graph with positive edge weights runs in O(nm+n2 log n) time, resulting in a trivial O(n3m+n4 log n) time algorithm for computing the optimal edge. Firs...

abstract: in this paper, optimization of boeing 747 wing has been accomplished for cruise condition (mach number=0.85, flight altitude=35000 ft), where an optimal wing shape is proposed. objective functions are minimization of wing weight and drag force that as well as confining design parameters, two functional constrains are applied. the first functional constrain is fuel tank volume in the a...

We present a fluid dynamics video showing the behavior of Leidenfrost droplets composed by a mixture of water and surfactant (SDS, Sodium Dodecyl sulfate). When a droplet is released on a plate heated above a given temperature a thin layer of vapor isolates the droplet from the plate. The droplet levitates over the plate. This is called the Leidenfrost effect. In this work we study the influenc...

A mononuclear nonheme ferric-peroxo complex bearing a macrocyclic tetradentate N4 ligand, [(TMC)Fe(III)-O2]+, was prepared and used in mechanistic studies of aldehyde deformylation; a catalytic aldehyde deformylation by a nonheme iron(II) complex, [Fe(II)(TMC)]2+, and molecular oxygen is reported as well.

Structure and properties of magnesium silicate borate melts glasses were investigated by using newly parameterized interaction potentials in molecular dynamics simulations compared with those calcium borate. The competition between the depolymerization silica network formation new bonds modifier ions leads to enhancement elastic moduli increasing content alkaline earth glasses. Compared silicat...