Texture profile parameters of frankfurters were found to be generally related to cooking temperatures, except for degree of elasticity, hysteresis loss, and work ratio. Cohesiveness, elasticity, gumminess, and chewiness all were polynomial functions of cooking temperature and were smallest at 70‐75° C where physico‐chemical changes in proteins important to texture development appeared to be occurring. Hardness, compression energy of first bite, brittleness, apparent moduli of elasticity, stress at 20% compression and strain energy of compression per unit volume were all linearly related to the cooking temperature. Texture profile parameters were higher for samples with higher protein and lower moisture contents at all cooking temperatures.

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Use of modal testing and structural dynamic modification techniques for prediction of the modal parameters of a PC board with a surface-mount component is described. Experimentally determined natural frequencies and mode shapes of a PC board with and without an added component are presented. Several simple dynamic models of the component are evaluated. Results obtained indicate that the component can sometimes be modeled as a point mass.

Some of the qualitative aspects of the parametric excitation of a viscoelastic column are investigated. The problem considered is that of an initially straight, simply supported, viscoelastic column subjected to a harmonically varying axial load. The column material is assumed to be adequately represented by simple spring-dashpot models. Linear theory is used throughout. An approximate method for determining the stability characteristics of the governing equations is outlined briefly. This method is applied to several specific examples for the cases of a material behaving as a Maxwell and three-parameter model. In most cases the resulting instability regions have the same general appearance as those for the elastic case with varying amounts of viscous damping. In some cases, however, the regions are broadened significantly and shifted toward lower values of the exciting frequency as the material becomes more viscoelastic in nature. In these cases, there is a certain "critical" value beyond which an increase in damping has a destabilizing effect. In the examples for the Maxwell material, no specific interaction between the creep instability and parametric instability is revealed. NomenclatureA = dimensionless frequency parameter = (2Q/co) 2 Cj = constant used in method of variation of parameters djk = element in the jih row and kih column of the matrix D EI, Ez = spring coefficients for viscoelastic models fjk -element in the jih row and kih column of the matrix F f(t) = time portion of motion i = (-1) 1/2 / = second moment of column cross section k = material constant = (1 + r 2 /ri -f-Ei/Es) k' = material constant = (1 + Ei/Ez] k* -material parameter = k'/rz kz p = dimensionless material parameter for threeparameter model = fc*/fi k m = dimensionless material parameter for Maxwell model = l/(rifl) L = length of column m = column mass per unit length M(x, t) = internal bending moment P(0 = axial load = P 0 + Pi coscoi PO = static component of load Pi = amplitude of dynamic component of load P* = Euler critical load for elastic column t = time u(x, t) = d 2 i//dZ 2 -PK/TU x = axial distance along undenected column Xj = the jth element of the column matrix x Xj w = elements in perturbational part of solution y(x, t) -lateral displacement of column z = distance from centroid of cross section to a given fiber in plane of curvature OLJ -real part of Ay |8j= imaginary part of X/ e = load parameter = P X /(P* -P 0 ); also strain eo = strain at centroid of cross section e* = load parameter = (l/r 2 )[(P* -k'P 0 )/(P* -P 0 )] e zp = dimensionless load parameter for three-parameter model = c*/k* e m = dimensionless load parameter for Maxwell model = Po/(P* -Po) _ ?7 = amount of detuning from a critical frequency K(X, t) = curvature of column \i = the jih element of the diagonal matrix B AI, A2 = damping coefficients for viscoelastic models or = stress n, T 2 = material constants = \i/Ei, \*/E* co = frequency of dynamic component of load 17-natural frequency of lateral vibration of elastic column with axial load P 0 ( ' ) =...