A derivation of the Dirac equation in ‘3 + 1’ dimensions is presented based on a master equation approach originally developed for the ‘1+ 1’ problem by McKeon and Ord. The method of derivation presented here suggests a mechanism by which the work of Knuth and Bahrenyi on causal sets may be extended to a derivation of the Dirac equation in the context of an inference problem.

Measurements in atmospheric science sometimes determine universal functions, but more commonly data are collected in the form of case studies. Models are conceptual constructs that can be used to make predictions about the outcomes of measurements. Hypotheses can be expressed in terms of model results, and the best use of measurements is to falsify such hypotheses. Tuning of models should be av...

A measurement device for sieve plates have been designed and built at Helsinki University of Technology. The unit consists of a rectangular transparent container where one plate is installed. The flow path on the plate is of constant width. The plate is easy to change and sieve plates with two different diameters of holes have already been measured. The measurements have been done with two syst...

Mechanically driven orographic lifting is important for air pollution dispersion and weather prediction, but the small dimensions of mountain peaks often prevent numerical weather models from producing detailed forecasts. Mechanical lifting in stratified flow over mountains and associated thermodynamic processes were quantified and evaluated using Sheppard’s model to estimate the dividing-strea...

The plate-type coalescer was constructed and tested for the continuous separation of immiscible liquids in micro-scale. Two plates formed the main structure of the coalescer. A flat and rectangular channel was situated between the plates. The material options for the plates were PTFE, stainless steel and glass which formed the contact surfaces for the fluids in the device. The liquid-liquid dis...

The minimisation of birefringence, or polarisation mode dispersion, is vital for simplifying and miniaturising photonic components. In this work, we present a systematic study of the slot waveguide geometries required for having zero birefringence (ZB). We show that the rail widths required for ZB are more strongly dependent on the height of the waveguide than on the slot separation. After whic...

This study investigates the height dependency of aerosol-cloud interaction regimes in terms of the joint dependence of the key cloud microphysical properties (e.g., cloud droplet number concentration and cloud droplet relative dispersion) on aerosol number concentration (Na) and vertical velocity (w). The three distinct regimes with differentmicrophysical features are the aerosol-limited regime...

This paper presents the results of a theoretical-experimental study on influence FDM parameters (height deposited layer at one pass Hs and percentage filling Pu) dimensions cylindrical spur gears made PLA (shaft diameter d bore D). In this context, we designed 3D model gear with module m= 1 z= 60 teeth, which used for printing 27 parts different values coating height pitch 0.10, 0.15, 0.20mm 50...