Sensory analysis of polystyrene packaging material taint in cocoa powder for drinks and chocolate flakes

Polystyrene packaging material taint was sensorily evaluated in cocoa powder for drinks and chocolate flakes using short-cut signal detection measures on differences between control and test samples and on recognition of styrene. No differences were observed in cocoa powder for drinks and plain chocolate flakes treated with 0.5 dm2 polystyrene of 1 mm thickness. However, differences were detected in milk chocolate flakes and plain chocolate flakes, which were in contact with a larger area or thicker polystyrene packaging material. The latter results were confirmed by the styrene recognition test, so polystyrene is a potential source of off-flavour for chocolate products. The amount of residual styrene in the polystyrene used was about 320 ppm, while the amounts of styrene ranged from 7 to 132 ppb in cocoa drinks and from 414 to 1447 ppb in chocolate flakes.     

On the uniqueness of some helical flows of a second grade fluid

Summary The uniqueness of some helical flows of a second grade fluid, between two infinite circular cylinders, is proved. Initially, the fluid is at rest and flow is produced by the motion of the cylinders. Finally, the special case of a flow in a circular cylinder is considered.     

Solution of Helmholtz equation by Trefftz method

The application of the Trefftz method for calculating wave forces on offshore structures is presented. Indirect and direct formulations using complete and non-singular systems of Trefftz functions for the Helmholtz equation are posed in this paper. An effective technique using different interpolation functions for the velocity potential and wave force are suggested to improve the computational accuracy of the wave force. The numerical examples show that the present method is highly efficient and accurate.     

Comparison of D.C. and A.C. techniques for the evaluation of inhibitor efficiency in acid corrosion

Five different techniques (analytical determination of dissolved iron, Tafel line extrapolation, linear polarization method, impedance and Faradaic distortion measurements) were used for the evaluation of the inhibiting efficiency of N-decyl-3-hydroxypyridine bromide in 1 M hydrochloric acid solutions. The results obtained with the different methods were found to agree satisfactorily. High inhibiting efficiency value was obtained at 1× 10^?4Mdm^?3 concentration.     

Axial-Field Electrical Machines - Design and Applications

Axial-field electrical machines offer an alternative to the conventional machines. In the axial-field machine, the airgap flux is axial in direction and the active current carrying conductors are radially positioned. This paper presents the design characteristics, special features, manufacturing aspects and potential applications for axial-field electrical machines. The experimental results from several prototypes, including d.c. machines, synchronous machines and single-phase machines are given. The special features of the axial-field machine, such as its planar and adjustable airgap, flat shape, ease of diversification, etc., enable axial-field machines to have distinct advantages over conventional machines in certain applications, especially in special-purpose applications.     

Location errors in tachistoscopic recognition: Guesses, probe errors, or spatial confusions?

Examined whether location errors in tachistoscopic visual probe tasks reflect (1) uncertainty about the actual position of items, (2) inappropriate guesses, encouraged by a requirement to respond, or (3) confusion about the position being tested. 46 undergraduates completed probe tasks in which they provided confidence ratings on each trial and tasks that substituted a color cue for a visual pointer or used a double bar probe. Results suggest that location errors on visual probe tasks reflect confusion about the spatial position of target items. Findings are consistent with data questioning the concept of iconic memory and imply that the bar-probe task cannot be used to study precategorical visual memory. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An Analysis of Scheduling Policies In Multiechelon Production Systems

Results of a simulation study of the economics of frequency of rescheduling Material Requirements Planning (MRP) systems are presented for a single-product, two-stage system in which demand is uncertain. The results indicate that for systems with moderate demand uncertainty, frequent rescheduling to maintain customer service may be uneconomical when compared with the alternative of more stable schedules in conjunction with safety stock. This result arises primarily because the cost of “emergency” production setups which occur when rescheduling is frequent exceeds the cost of safety stock required to “protect” stable schedules.     

Highly monomode W1 waveguide square lattice photonic crystal lasers

Lasing of W1 square lattice-based photonic crystal lasers on the substrate approach is analyzed. A second-order distributed feedback highly monomode behavior is observed. A comprehensive two-dimensional and three-dimensional finite-difference time-domain computation analysis shows that this characteristic arises from the lattice geometry. Single-mode lasers can be obtained using this geometry, opening the way to the realization of monomode laser arrays.