THREE TYPES OF CITRUS PEEL WASTE AS SOURCES OF COLOR

SUMMARY –Pilot-scale extractions of orange peel color concentrates from whole peel, peel frits and flavedo were reported. Yields of color up to 402, 545 and 669 mg/kg of starting material were obtained from frits, whole peel and flavedo, respectively. Additional color was obtained by acetone treatment of emulsion and this process increased yields by 1% from whole peel, 33% from flavedo and 50% from frits. All three of these waste materials appear to provide good sources of natural orange color. From the standpoint of yield, flavedo was best. Whole peel, although affording the lowest yield of color, offers the advantage of being considerably easier to handle due to lack of emulsion.     

SPECTRORADIOMETRY AND COLORIMETRY IN THE LIGHTING INDUSTRY

Spectroradiometry is fundamental in the measurement and evaluation of color. It is used in the evaluation of new light sources, in the analysis of problem areas, and for the compilation of data for inclusion in the technical brochures describing lighting products. The basic elements of a spectroradiometer are described and the application of spectral-power distribution measurements to photometry and colorimetry is illustrated.     

USE OF ULTRAFILTRATION/REVERSE OSMOSIS SYSTEMS FOR THE CONCENTRATION AND FRACTIONATION OF WHEY

SUMMARY– Existing ultrafiltration/reverse osmosis technology provides a means of fractionating and concentrating cheese whey into liquid fractions containing a variety of protein: lactose ratios. These ratios may range from about 1:8 (raw whey) through 3:5 (a "skim milk equivalent") to 2:1 or higher. If a two- or three-stage ultrafiltration system were used with water injection between stages, a product with a protein:lactose ratio of 20:1 could be obtained. The exact protein:lactose ratio in the concentrate stream is a function of the permeability and selectivity characteristics of the membrane, and the system design and operating conditions. Some of the sanitation problems associated with the introduction of these new unit operations in the dairy and food processing industries are also treated at length.     

Trajectory control of a PUMA robot arm by inversion and servocompensation

Based on invertibility and functional reproducibility, an approach to the control of the PUMA arm with six rotational degrees of freedom is presented. The control system has two important features: (i) the ability for fast, precise trajectory tracking; and (ii) robustness to uncertainty in the system, such as variable payload, inertia, etc. The control law derived using invertibility gives decoupled, independently controlled responses in each joint angle using torquers. For robustness, a first-order servocompensator is designed for each decoupled inner loop driven by the joint angle error. For smooth joint angle responses, a command generator is constructed that produces the reference trajectories to be tracked. Simulation results are presented to show that rapid, accurate trajectory following is achieved in the closed-loop system in spite of large payload uncertainty.     

Optimal Hankel-norm approximation approach to model reduction of large-scale Markov chains

A model reduction problem of certain large-scale Markov chains under an optimal criterion for Hankel-norm approximation is discussed. The multi-dimensional Markov chain under investigation is assumed to have a finite-dimensional stationary state-transition matrix, which is first reformulated as a multi-input/multi-output (MIMO) linear time-invariant (LT1) stochastic system. Consequently, the resulting large-scale MIMO LTI stochastic system has a closed-form best approximant in the Hankel-norm from a specified class of stable lower-dimensional MIMO LTI systems.     

Matrix formulae for open and closed-loop approximate model matching in frequency domain

This paper concerns model matching of SISO systems in the frequency domain. The matching uses Pade coefficients and Markov parameters of a reference model of which the final system will be an approximation. Because the matching is approximate, constraints on the structures of both the reference model and the final system can be somewhat relaxed. In this paper an easy-to-implement matrix formulation is derived for both open- and closed-loop matching problems. Some results concerning pole-zero cancellations are presented, along with a number of numerical examples provided to illustrate the usefulness and simplicity of the approach.     

Dyadic output feedback laws generated as Kronecker products : optimal and suboptimal solutions

The problem of eigenvalue assignment in the system dx/dt equals; Ax + Bu, y = Dx, using the dyadic output feedback law u = u₀ + q · p^Ty is considered via a formulation developed earlier by the author, in which p and q occur in the Kronecker product vector p?q. The equations governing the values of p and q which give an optimum approximation to a prescribed spectrum of eigenvalues are derived, and a special case is solved. Various facets of the problem of generating suboptimal solutions are discussed.     

Arbitrary eigenvalue assignments for linear time-varying multivariable control systems

The problem of eigenvalue assignments for a class of linear time-varying multi-variable systems is considered. Using matrix operators and canonical transformations, it is shown that a time-varying system that is ‘lexicography-fixedly controllable’ can be made via state feedback to be equivalent to a time-invariant system whose eigenvalues are arbitrarily assignable. A simple algorithm for the design of the state feedback is provided.     

Design of reduced-order state estimators for linear time-varying multivariable systems

The design of reduced-order state estimators for linear time-varying multivariable systems is considered. Employing the concepts of matrix operators and the method of canonical transformations, this paper shows that there exists a reduced-order state estimator for linear time-varying systems that are ‘lexicography-fixedly observable’. In addition, the eigenvalues of the estimator can be arbitrarily assigned. A simple algorithm is proposed for the design of the state estimator.