more recently, titanium and aluminum alloys are gaining more interests to be implemented in hydro-forming applications. it is necessary to predict forming limits for these sheet alloys. forming limits play an important role in metal forming processes. forming limit diagrams, present the limit strains for various linear strain paths. in other hand, forming limit curve (flc), illustrates localize...

conclusions the analytical sensitivity of lamp and pcr methods, using the designed primers, was 8 times more than any other reported methods. the designed methods are specific and sensitive for detection of h. pylori in different clinical and environmental samples. results the detection limits of the lamp and pcr assay were similar and were 10 fg of pure dna of h. pylori, which is equal to 6 co...

High temperature impact melt breccias from the Rochechouart (France) meteorite crater record a magnetization component with antipodal, normal and reverse polarities. The corresponding paleomagnetic pole for this component lies between the 220 Ma and 210 Ma reference poles on the Eurasian apparent polar wander path, consistent with the 214±8 Ma Ar/Ar age of the crater. Late Triassic tectonic rec...

In this paper we give sufficient conditions to ensure uniqueness of limit cycles for a class of planar vector fields. We also exhibit a class of examples with exactly one limit cycle.

A simple scoring system based on skin colour, skin texture, breast development, and ear firmness that can be performed even in an ill baby without manipulation or movement enables gestational age to be estimated to within +/- 15 days (95% confidence limits) at any time in the first 2 days of life. More complex techniques only marginally improve this estimate.

We study quadratic perturbations of the integrable system (1 + x)dH, where H = (x2 + y2)/2. We prove that the first three Melnikov functions associated to the perturbed system give rise at most to three limit cycles.

We consider a planar differential system ˙ x = P (x, y), ˙ y = Q(x, y), where P and Q are C 1 functions in some open set U ⊆ R 2 , and ˙ = d dt. Let γ be a periodic orbit of the system in U. Let f (x, y) : U ⊆ R 2 → R be a C 1 function such that P (x, y) ∂f ∂x (x, y) + Q(x, y) ∂f ∂y (x, y) = k(x, y) f (x, y), where k(x, y) is a C 1 function in U and γ ⊆ {(x, y) | f (x, y) = 0}. We assume that i...

39 We shall give three ' criteria for the uniqueness of limit cycles of systems of Liellard type x '= a(y)-f3(y)F(x}, y '= -g(x}, examples are provided to illustrate our results.

Motivated by the recent work of Louko and Molgado, we consider the Ashtekar-Horowitz-Boulware model using the projection operator formalism. This paper uses the techniques developed in a recent paper of Klauder and Little to overcome the potential difficulties of this particular model. We also extend the model by including a larger class of functions than previously considered and evaluate the ...