Fouling and Flux Restoration of Ultrafiltration of Passion Fruit Juice

Fouling phenomena of passion fruit juice in tubular ultrafiltration (UF) system were studied. The membrane deposit was found to be composed of pectin, sugars, citric acid, hemicellulose, and cellulose. Rinsing behaviour of the fouled membrane indicated that the deposit might be in the form of gel. Scanning electron microscopic examinations showed slime-like deposit on the fouled membrane. Intermittent on-off operation was able to restore the flux effectively. Rebounding of the gel layer at sudden release of pressure may explain the effect of on-off operation on flux restoration.     

Egg White Lysozyme Purification by Ultrafiltration and Affinity Chromatography

Isolation and purification of lysozyme from hen egg white was studied using a two-step procedure. The egg white was diluted 5- to 9-fold with sodium phosphate buffer, and then processed by sequential dilution diafiltration using a UF membrane (molecular weight cut-off 300,000 dalton). The membrane process increased the specific activity of lysozyme 6-fold, and recovered 96% of lysozyme activity. The permeate from diafiltration was further purified by affinity chromatography using chitin as adsorbent. The second step of the process yielded a product of specific activity of 70,400 units/mg protein. The overall lysozyme recovery was 79%.     

Influence of a Tangential Force on the Fracture of Two Contacting Elastic Bodies

The problem of fracture initiation at two elastically contacting structural components, subject to applied normal and tangential forces, was analyzed. The fracture initiation load was predicted to depend sensitively on the magnitude of the applied tangential force and the interfacial friction coefficient, and to exhibit important dependencies on the fracture toughness, elastic modulus, and curvature of the contacting bodies. Experimental results obtained on glass and Si₃N₄ conform with the trends predicted by the analysis.     

Matching strengths of answers in fuzzy relational databases

Imprecise information is represented by fuzzy disjunctive information, and an extended fuzzy relational model is used to accommodate such information. In the presence of imprecise information, answers to a query can be categorized into two kinds of answers: sure answers and possible answers. To find more likely answers to a given query, the authors develop a method to measure the matching strength of each tuple as an answer to the query. The quality of an answer is higher in the case where less extra information is required and the more sure information is provided     

Mushroom Blanch Water Concentration by Membrane Processes

Mushroom blanch water was concentrated by ultrafiltration (UF) and reverse osmosis (RO). UF prefiltration was essential in preventing severe fouling during the RO process. When the UF blanch water permeate was processed by RO, linear relationships between pressure and flux were observed at all concentrations tested. The blanch water was concentrated by UF/RO from 2% to 13% total solids at 60°C and 120 KPa/5000 KPa operating pressures with flux higher than 15 L/m² hr. Maximum concentration obtained was approximately 20% total solids with 90% recovery of the nonvolatiles. Recoveries of some major volatiles were above 50%. Panelists could not differentiate the original from the reconstituted blanch waters in sensory evaluations.     

Heuristic unidirectional flowpath design approaches for automated guided vehicle systems

In this paper, we address the flowpath design issue of automated guided vehicle systems (AGVSs). In particular we concentrate on the design of unidirectional flowpaths (i.e. vehicles are restricted to travel only in one direction along a given segment of the flowpath). We have developed five different heuristics for the design of unidirectional AGVSs. We have also developed simulated annealing algorithms for the above problem. Our extensive computational results indicate that a composite heuristic (i.e. one that combines the most successful of our five heuristics) yields solutions of comparable quality in a fraction of the time required by simulated annealing. For large-size flowpath design problems, we advocate the usage of composite heuristics over simulated annealing, and in particular for the cases in which inaccurate estimates for the input data in our design problem exist     

A SEQUENTIAL QUADRATIC PROGRAMMING ALGORITHM UTILIZING QR MATRIX FACTORIZATION

Some recent studies indicate that the sequential quadratic programming (SQP) approach has a sound theoretical basis and promising empirical results for solving general constrained optimization problems. This paper presents a variant of the SQP method which utilizes QR matrix factorization to solve the quadratic programming subproblem which result from taking a quadratic approximation of the original problem. Theoretically, the QR factorization method is more robust and computationally efficient in solving quadratic programs. To demonstrate the validity of this variant, a computer program named SQR is coded in Fortran to solve twenty-eight test problems. By comparing with three other algorithms: one multiplier method, one GRG-type method, and another SQP-type method, the numerical results show that, in general, SQR as devised in this paper is the best method as far as robustness and speed of convergence are concerned in solving general constrained optimization problems.     

Desalination of the Spent Brine from Pickled Prunes Processing by Electrodialysis

The feasibility of desalting the spent brine from pickled prune processing by electrodialysis was studied. Three membrane pairs were tested and one was selected for the process. The limiting current density increased with increasing fluid velocity as well as increasing salt concentration. Increasing current density increased the ion removal rate, the rate of water transport, the power consumption per unit mass of salt removal, and decreased current efficiency. However, the losses of citric acid and benzaldehyde did not increase significantly until the current density was up to 10 mA/cm². The electrodialysis process removed 88% salt from the brine while retaining 80% organic acids and 55% benzaldehyde.     

On a reliable data communication broadcast system

This paper describes the design and implementation of a 3 KHz band HF data broadcast communication system, using a quantized frequency modulation, adaptive lattice equalizer together with forward error correcting code (FEC) to obtain a high link reliability and low error rate. A frequency diversity approach is also used in the selection of the timely best carrier frequency, and a microcomputer is implemented into the system for automatic best carrier acquisition, data transmission and clock synchronization, with minimum operator's attention. Extensive field experiments were conducted and experimental results indicate that the system can achieve, for daytime operation, a link reliability of 87–98%, with a probability of error between 10^?4 to 10^?5, depending upon data rate (50, 75bps) and FECs used. For night time operation, the link reliability reduces to from 65–93% with a probability of error down in the order of 10^?3.