Microbiological Evaluation of Alaska Shore-based Surimi Production

Two shore-based surimi plants in Alaska were investigated to determine microbial conditions of Alaska pollock flesh during processing. Median aerobic plate count (APC) was 2.0 × 10³/g after mincing, 2.3 × 10³/g after washing/screening, 4.2 × 10⁴/g after refining and 1.6 × 10⁴/g after dewatering. Reprocessing, needed for nonanalog grade surimi, resulted in APC of 1.2 × 10⁵/g after a second refining and 3.0 × 10⁵/g after a second dewatering. The APC for analog grade surimi was 5.5 × 10⁴/g and 2.0 × 10⁶/g for nonanalog grade surimi. Highest total coliform most probable number (MPN) of > 1100/g was determined from a nonanalog grade surimi sample and from a mince that had been refined twice. Highest Escherichia coli MPN of 460/g was determined from two minces.     

Effect of Added Lactobacilli on Composition and Texture of Cheddar Cheese During Accelerated Maturation

The evolution of cheese composition and texture was studied in maturing Cheddar cheese supplemented with live cells and cell homogenates of Lactobacillus casei-casei L2A in order to accelerate maturation. The pH was significantly modified by the lactic acid of the bacterial additives. The Theological properties showed the same general pattern of evolution in experimental as in control cheeses. The process we developed has led to a good-quality matured cheese with 40% increase in flavor intensity compared to control cheeses.     

Process Parameter Effects on Particle Residence Time in a Vertical Scraped Surface Heat Exchanger

Residence times of 1.0-2.0 cm potato cubes with 0.4-1.2% aqueous solutions of sodium carboxymethyl cellulose flowing at 453-599 mli sec were investigated in a vertical scraped surface heat exchanger rotating at 60 160 rpm. Minimum and maximum normalized particle residence times (NPRTs) standard deviation of mean NPRTs, and characteristic parameter for tanks-in-series models were not significantly affected by particle concentration. Mean NPRT for 40% particle concentration was significantly higher than those of single particle - 20% particle concentrations. Mean NPRTs were significantly influenced by process parameters and 2-way interactions.     

Electrochemical characteristics of phosphorus doped Si-C composite for anode active material of lithium secondary batteries

Phosphorus doped silicon-carbon composite particles were synthesized through a DC arc plasma torch. Silane(SiH₄) and methane(CH₄) were introduced into the reaction chamber as the precursor of silicon and carbon, respectively. Phosphine(PH₃) was used as a phosphorus dopant gas. Characterization of synthesized particles were carried out by scanning electron microscopy(SEM), X-ray diffractometry(XRD), X-ray photoelectron spectroscopy(XPS) and bulk resistivity measurement. Electrochemical properties were investigated by cyclic test and electrochemical voltage spectroscopy(EVS). In the experimental range, phosphorus doped silicon-carbon composite electrode exhibits enhanced cycle performance than intrinsic silicon and phosphorus doped silicon. It can be explained that incorporation of carbon into silicon acts as a buffer matrix and phosphorus doping plays an important role to enhance the conductivity of the electrode, which leads to the improvement of the cycle performance of the cell.     

Refinement of circular-polarization based on multilayer film structure

Circular-polarization discrimination appears in many antennas' applications. A compensation approach based on multilayer film structure is proposed to improve the axial ratio of the magnitude of the two perpendicular modes of the lump ports. The goal is to widen the beamwidth of radiation that has an axial ratio less than 3 dB and thus reducing the complexity at the receiver. A transfer matrix method was developed to represent the multilayer film and characterize its performance. Simulation using high frequency structure simulator shows that a crossed dipole, as an example, can achieve a beamwidth of more than at the frequency of 12.45 GHz after compensation. Finally, conclusions and future work about this compensation method are presented.