Ground Research Articles

Influence of finite ground planes on the transmission line current distribution

The knowledge of the current distribution on the ground plane of a printed circuit board (PCB) is important to overcome many electromagnetic compatibility (EMC) problems. In this paper a method of moments (MoM) algorithm is used to evaluate the surface current distribution on the ground (GND) plane. In order to consider the effects of GND-planes on the signal behaviour on transmission lines, infinite planes are often assumed to reduce the calculation time. A comparison of the currents using finite and infinite ground planes shows a significant modification of the coupling to transmission lines placed in the layer above.

Gel Electrophoretic Analysis of the Protein Changes in Ground Beef Stored at 2°C

ABSTRACTPurified myofibrils and sarcoplasmic proteins were prepared from ground (GR) and intact (CON) beef semitendinosus muscle samples after 0, 1, 3, 6, and 10 days of storage at 2°C. SDS‐polyacrylamide gel electrophoresis analysis revealed the following major postmortem changes in GR samples: the gradual disappearance of nebulin and desmin, appearance of 110,000‐, 95,000‐ and 30,000‐dalton polypeptides, and an increased content of myosin light chain‐3 and 55,000‐dalton component in myofibrils. Also noted was emergence of 100,000‐ and −500,000‐dalton polypeptides and diminution of 300,000‐dalton protein in the sarcoplasmic fraction. Since GR samples showed proteolytic changes similar to those of CON samples, it was concluded that grinding had little effect on postmortem muscle protein degradation.