Trong bài báo này, ?nh h??ng c?a ?i?u ki?n th?y nhi?t và nung ??n c?u trúc nano-hydroxyapatite ???c t?ng h?p t? x??ng cá ng? b?ng ph??ng pháp ?ã nghiên c?u. Các tính ch?t lý hóa s?n ph?m xác ??nh các phân tích hi?n ??i nh? nhi?u x? tia X (XRD), quang ph? h?ng ngo?i bi?n ??i Fourier (FTIR), hi?n vi ?i?n t? quét phát tr??ng (FE-SEM), truy?n qua (TEM) hu?nh (XRF). K?t qu? XRD cho th?y ?? k?t tinh ...

We consider attractor varieties arising in the construction of dyonic black holes in CalabiYau compactifications of IIB string theory. We show that the attractor varieties are constructed from products of elliptic curves with complex multiplication for N = 4, 8 compactifications. The heterotic dual theories are related to rational conformal field theories. The emergence of curves with complex m...

Recently, a one-parameter deformation of the Maldacena-Núñez background was constructed in hep-th/0505100. According to the Lunin-Maldacena conjecture, the background is dual to pure N = 1 SYM in the IR coupled to a KK sector whose dynamics is altered by a dipole deformation that is proportional to the deformation parameter γ. Thus, the deformation serves to identify the aspects of the gravity ...

We present a version of ten-dimensional IIA supergravity containing a 9-form potential for which the field equations are equivalent to those of the standard, massless, IIA theory for vanishing 10-form field strength, F 10 , and to those of the 'massive' IIA theory for non-vanishing F 10. We present a multi 8-brane solution of these equations that generalizes the 8-brane of Polchinski and Witten...

We continue the work hep-th/0411075 considering here the case of degenerate masses. A nonabelian vortex arises in r-vacua upon the breaking by a superpotential for the adjoint field. We find the BPS tension in the strong coupling regime computing the dual-quark condensate. Then we find that it is equal to a simple quantity in the chiral ring of the theory and so we conjecture the validity of ou...

Let V be 2n-dimensional vector space over a field K equipped with a nondegenerate skew-ψ-Hermitian form f of Witt index n ≥ 1, let K0 ⊆ K be the fix field of ψ and let G denote the group of isometries of (V, f). For every k ∈ {1, . . . , 2n}, there exist natural representations of the groups G ∼= U(2n,K/K0) and H = G∩SL(V ) ∼= SU(2n,K/K0) on the k-th exterior power of V . With the aid of linear...

The addition of fundamental degrees of freedom to a theory which is dual (at low energies) to N = 2 SYM in 1+3 dimensions is studied. The gauge theory lives on a stack of Nc D5 branes wrapping an S with the appropriate twist, while the fundamental hypermultiplets are introduced by adding a different set of Nf D5-branes. In a simple case, a system of first order equations taking into account the...

We compute the spectrum of color-singlet fermionic operators in the N = 2 gauge theory on intersecting D3 and D7-branes using the AdS/CFT correspondence. The operator spectrum is found analytically by solving the equations for the dual D7-brane fluctuations. For the fermionic part of the D7-brane action, we use the Dirac-like form found by Martucci et al. (hep-th/0504041). We also consider the ...

Let Θ be a point in R. We are concerned with the approximation to Θ by rational linear subvarieties of dimension d for 0 ≤ d ≤ n−1. To that purpose, we introduce various convex bodies in the Grassmann algebra Λ(R). It turns out that our convex bodies in degree d are the d-th compound, in the sense of Mahler, of convex bodies in degree one. A dual formulation is also given. This approach enables...

The supersymmetric (AdS3×S)/ZN orbifold constructed by the authors in hep-th/0106171 is shown to describe AdS fragmentation, where fivebranes are emerging from the F1-NS5 background. The twisted sector moduli of the orbifold are the collective coordinates of groups of n5/N fivebranes. We discuss the relation between the descriptions of this background as a perturbative string orbifold and as a ...