Machine separated flesh from American shad (Alosa sapidissima) was evaluated for preparing heat set gel products. Round fish frozen for 15) to 10 months at -18°C served as raw material for processing investigations. The effectiveness of various additives and processing procedures for improving gel strength and sensory characteristics were determined. Addition of 0.5% polyphosphate to sols enhanced the hardness (P [greater than or equal to] .005), cohesiveness (P [greater than or equal to] .01) and springiness (P [greater than or equal to] .001) of heat set gels. Small amounts (0.5 and 1.0%) of dried egg white also improved hardness, cohesiveness and springiness (P [greater than or equal to] .001). Employing a two stage heat setting regime (40°C for 30 min followed by 90°C for 20 min) strengthened (hardness, cohesiveness and springiness) (P [greater than or equal to] .001) gels over a one stage (90°C for 30 min) heat set. Two stage heating improved gel strength when sol fonnulations contained additives that improved, lowered or exerted no effect on gel strength. Concentrations of dried egg white (1.0, 2.0, 3.0 and 4.0%) and potato starch (1.0, 2.0 and 5.0%) did not improve gel strength. Dried egg white (>1%) did not alter (P > .05) any physical parameters of gel texture. Potato starch (>1%) reduced gel hardness (P [greater than or equal to] .001). More basic pH conditions produced by the addition of 0.1 and 0.2% sodium carbonate to sols did not alter gel hardness or springiness (P < .05) and only caused a slight inprovement in cohesiveness (P [greater than or equal to] .001). Ihe cryoprotectants sorbitol, (0.0, 2.0, 4.0, 6.0 and 8.0%) and sucrose (0.0, 2.0, 4.0 and 6.0%), reduced gel strength in a concentration dependent manner. Gel hardness was reduced in a linear manner as fish protein was replaced with sorbitol (r =.976) or sucrose (r =.965) in sols formulated to contain 74 + 1.5% moisture. Cohesiveness was reduced in a similar manner (r = .942) by sorbitol, but not by sucrose. Gel springiness was not altered by additions of sorbitol or sucrose. Incorporation of sucrose into formulations reduced sensory preference for the texture, flavor, appearance and overall desirability of heat set gels. Analysis of covariance of texture preference scores and physical measurements of texture reveal a strong linear correlation with hardness (P =.0004), but not with cohesiveness (P =.6675). Within the range of sucrose levels evaluated, harder gels were preferred. Washing was evaluated for improving the strength and sensory preference for heat set gels containing 0.5% polyphosphate and 0.5% dried egg white. Sols were set by heating for 30 min at 40°C followed by 90°C for 20 min and exposed to wood smoke. Gel hardness and springiness were reduced by washing (P [greater than or equal to] .05), but not cohesiveness (P > .05). This was surprising, since the gel strength enhancing effect of washing is well documented. Sensory preference for the flavor, color, texture or overall desirability of heat set gels was not affected (P > .05) by washing. Mean overall desirability scores for gels prepared from unwashed minced flesh of 5.25 and 5.27 for washed minced flesh were only slightly above a neutral preference (5.0 = neither like nor dislike). Round shad yielded 65.06% planks, 41.20% minced flesh and 40.10% refined flesh. A single exchange wash followed by dewatering yielded 23.02% pressed flesh based upon round weight which was reduced to 20.68% by refining. Processing minced flesh into washed and refined flesh recovered 51.37% of total solids. The yield through refining was 97.33 and 89.83% respectively for unwashed and washed flesh. The protein and lipid content of flesh was not altered (P > .05) by washing, but ash content was reduced (P [less than or equal to] .001). / Graduation date: 1989

No description available.

No description available.

No description available.

No description available.

No description available.

No description available.

Chaos, an unstable steady-state phenomenon, arises in apparently random optical sequences from semiconductor lasers subjected to reflection. This condition, referred to as cacophony, might provide a new pseudo-random source for use in coherent fibre optic systems. Coherent optical signal processing is expected to find substantially increased application, especially in local data networks. An optical spread-spectrum source may suit two apparent needs of these networks: 1) a high resolution optical time-domain reflectometer, using correlation of sequences, which can identify the closely spaced features found in these systems; and 2) data security through optical frequency-hopping encryption, especially in broadcast data networks. The link between cacophony and chaotic processes suggests that, although noise like, the spectral evolution of cacophony is deterministic. This implied reproducibility, akin the binary pseudo-random sequences, would be advantageous in spread-spectrum applications. Experimental examination of reflection effects on lasers has explored various lasing and external reflection conditions. Computer simulation of cacophonous generators supplement the experimental work with quick trials of experiments under typical, hypothetical, or even unrealisable conditions. A new in-phase and quadrature equivalent circuit models optical magnitude with phase information, and with modest computing requirements. Cacophony has been generated experimentally and in the computer model, and reproducible sequences up to 10ns long have been demonstrated. Modelling shows that reproducibility may be improved if conditions, especially at the start of lasing, are better controlled. It is concluded that, in order to reach the kind of optical sequence reproducibility that is called for in the applications described above, it is probably necessary to introduce quantisation into the generator. The work has attempted to characterize optical cacophony, and has perhaps added some knowledge to the general problems of coherent optical signal processing.

No description available.

This dissertation describes the application of maximum entropy image restoration to envelope-detected ultrasonic sector scans. The maximum entropy restoration of the image of a point target (phantom) test object is shown to be superior to results obtained from the more familiar Wiener filter. The subsequent application of maximum entropy to an in-vivo clinical ultrasound image, however, illustrates the pitfalls associated with determining the relative merit of an ultrasonic image restoration technique from test object results alone. Since the resolution of sector scan images is substantially worse in the lateral (azimuthal) scan direction than the axial scan direction, the deconvolution filters described in this thesis were applied in the lateral direction only. The maximum entropy method is shown to have certain inherent advantages over linear frequency-domain techniques for the restoration of ultrasonic sector scan images. The positivity constraint inherent in the maximum entropy method is shown to produce restorations with substantially fewer oscillatory artifacts than those produced by Wiener filtering. In addition, the iterative nature of the maximum entropy algorithm is shown to be compatible with the restoration of the undersampled regions in the far field of sector scan images. The restoration of sector scan images is complicated by the spatially varying degradation associated with such images. A novel approach to the restoration of this class of image degradation is presented in this thesis. The widespread use of maximum entropy image restoration has been inhibited by the technique's demanding computational requirements. This problem can be alleviated by the use of high speed computer hardware, and the final chapters of this thesis describe the design and construction of a microcomputer-based array processor. The advantages inherent in the use of such hardware are demonstrated with reference to the maximum entropy restoration of ultrasonic images.