We construct a mass formula for the stringlike properties of qq mesons, based on the spectrumgenerating algebra U(4)@SUX(2)@ SU,( n )@ SU,( 3 ), with U(4) 3S0(4) dynamic symmetry. We determine the parameters appearing in this mass formula from fits to 57 well-established mesons in the Particle Data Group summary table. The average deviation for the mass squared of these mesons is 5.7% for our fit of all meson families combined. The mass formula allows us to distinguish meson states which are not qg type, such as ~~( 9 8 0 ) .

The mechanical behavior of a three-dimensional cross-linked fiber network embedded in matrix is studied in this work. The network is composed from linear elastic fibers which store energy only in the axial deformation mode, while the matrix is also isotropic and linear elastic. Such systems are encountered in a broad range of applications, from tissue to consumer products. As the matrix modulus increases, the network is constrained to deform more affinely. This leads to internal forces acting between the network and the matrix, which produce strong stress concentration at the network cross-links. This interaction increases the apparent modulus of the network and decreases the apparent modulus of the matrix. A model is developed to predict the effective modulus of the composite and its predictions are compared with numerical data for a variety of networks.

From recent experiments on low-energy Compton scattering on the proton, we extract a value (15.0 & 3.0) x fm3 for the paramagnetic polarizability ,Bp of the proton. We use the data on pion photoproduction to obtain a value (13k3) x h3 for the A contribution to ,Bp, much larger than that obtained from the quark model. 14.20.Dh, 13.60.F

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