The time characteristics or the appearance of interference phenomena may be continuous, intermittent or stochastic. External sources of interference are by their nature not dependent on the structure of the particular low voltage network, while the internal sources of interference are incorporated into the physical construction of the network itself, and may be unambiguously related to the foreseen operation and the way in which the network is used. The absolute level of interference is generally dependent on the strength and the characteristic of the source, the way of coupling to the victim and on the electrical characteristics of the operative low voltage power network.

As a result of the accident in the nuclear power plant at Chernobyl, USSR, a considerable increase in radioactive background radiation was noted in some regions of Sweden. In areas with high radioactive fallout an increase in the amount of lightning flashes was observed during the 1986 thunderstorm season. A statistical test shows that there is a risk of less than 1% that the observed difference has occurred by mere chance.

The effect of changes in weather on headache was investigated in two separate studies in Uppsala. In a pilot study 60 healthy persons (all medical staff) reported their headache during a period of 2 months. Later 53 patients with migraine and 20 with tension headache registered their headache during 4 weeks. Several climate factors were recorded during the observation periods. Both studies showed a significant weekly periodicity of headache. In patients with migraine the headache frequency was lowest on Sunday-Monday and highest on Thursday and on Saturday. In patients with tension headache the highest frequency was noted on Thursday-Friday and lowest frequency on Sunday-Tuesday. The pilot study showed that personnel off work had significantly more headache when bad weather occurred. There was a tendency for headache the day before windy weather. In the 53 migraine patients there was also a correlation between some climate factors and headache frequency. In this group the deviation from the expected headache frequency (actual headache frequency minus that of observed weekly periodicity) correlated significantly to the air-pressure and air-temperature measured 1-3 days later.

Eating styles of 30 obese women and 37 matched women of normal weight were observed unobtrusively in a fast-food restaurant in the search for an "obese eating style" or other differences between the two groups. The size and character of the food was carefully matched by giving each woman a coupon entitling her to a free meal of either 985 or 1,800 calories. There were only small and inconsistent differences between obese and normal-weight women. No evidence of an "obese eating style" was found.

The very large Raman scattering cross-section of adsorbed molecules, such as pyridine and CN-, on Ag is attributed to mechanisms involving either electron-hole pair excitations in the surface region of the metal or charge-transfer excitations between the metal substrate and the adsorbed molecules.

The giant RS by pyridine and CN− on Ag is accompanied by a strong RS continuum which is attributed to inelastic light scattering by charge carrier-excitations. The enhanced RS by the adsorbed molecules and by the charge carrier-excitations are attributed to surface roughness enhanced EM fields at the metal surface resulting from the excitation of transverse collective electron-excitations and surface-EM modes, and to surface roughness-induced radiative-excitation and radiative-recombination of particle-hole pairs.

The observation by Fleischmann, et al in 19741 of a strong Raman scattering (RS) in the visible by pyridine molecules adsorbed on a Ag electrode that had been roughened electrochemically by multiple oxidation-reduction cycles to increase the surface area, and the subsequent demonstration in 1977 by Jeanmaire and Van Duyne2 and by Albrecht and Creighton3 that the RS by pyridine molecules adsorbed on a Ag electrode following a single electrochemical oxidation-reduction cycle is greater by a factor of 105 to 106 than that of pyridine molecules in neat pyridine or in aqueous solution, has attracted widespread attention of theorists and experimentalists. Strongly enhanced RS has since then been observed for CN− and a number of other molecules adsorbed on Ag and an appreciably weaker RS has also been observed for molecules adsorbed on Cu, Pt and, more recently, on Au4–19.

A simplified theoretical model for atmospheric ions has been used to study the variation of small ion production rate. Linear equations have been derived to study the fluctuations of small and large ion concentrations with time. It is found that no oscillating solutions are possible. Using Bendixon's theorem it is shown that the same conclusion holds for the non-linear equations. The conclusions have been compared with the results of other workers.

Using classical molecular dynamics simulation and the Meyer–Entel interaction potential, we study phase transitions in a biphasic body-centered cubic (bcc)/face-centered cubic Fe crystallite under an applied shear strain. Our results show a strong temperature dependence. At low temperatures, both homogeneous and heterogeneous nucleation of the bcc phase is observed. At higher temperatures, but still below the equilibrium transition temperature, the bcc phase only grows by interface motion. Above the transition temperature, the bcc phase transforms homogeneously to the close-packed phase. In all cases studied, the unstrained system is stable and does not transform.

The variation of the cosmic ray intensity during a magnetic storm has been ascribed to the electrically polarized beam of particles from the sun. The loss of particles due to the total reflection in the electric field has been calculated. For comparison with observations, however, the change of intensity I per surface element dS, solid angle dω, and energy interval dW should be considered.

The influence of gaps for injection, acceleration, etc., on the stability of orbits in a strong-focusing synchrotron is examined and found not to be negligible. The calculation also gives some information about the resonances resulting from irregularities.

The stability of static magnetic fields in an electrically conducting liquid is investigated. The result of the study is applied to the stability of twisted cylindric magnetic fields. It is shown that instabilities may by caused by the twisting of a homogeneous field.

The importance of magneto-hydrodynamic phenomena to different parts of cosmic physics is becoming more and more evident. This fact and the extreme mathematical difficulties involved in an exact treatment of many problems make it necessary to consider the possibility for experimental investigations. In this paper the fundamental equations are solved for cylindrically limited waves, a case which seems to be best adapted for experiments. It is shown that an "ideal" magneto-hydrodynamic wave in a liquid with finite conductivity can exist only in a certain frequency interval. The upper limit is set by the conductivity and the magnetic field strength. Above this value the waves degenerate into skin-waves. The lowest frequency is determined by the geometrical dimensions and by the conductivity. Waves in different liquids are compared, and liquid sodium is found to be the best medium for an experiment. A brief account is given for a preliminary experiment and other investigations are proposed.