Algorithms for Bayesian background-subtracted Fourier darkfield imaging.

Formal consideration of prior information on the Fourier amplitude of background contrast in an image, using the same Bayesian principles of statistical inference which underlie thermodynamics, allows one to subtract background without favoring only selected parts of frequency space. Without the bias in frequency space which causes periodicity bleeding and mars literal interpretation of Fourier-filtered images, the shape transform of aperiodic objects can be left intact. Algorithms for Bayesian background subtraction from one- and two-dimensional images are presented which further consider, in ad hoc fashion, one's uncertainty about background amplitude. The results help explain the reported success of Fourier truncation, and indicate that Bayesian background-subtracted images can minimize root-mean-square image error, as well as periodicity bleeding, in comparison to Fourier-filtered and Fourier-truncated alternatives.     

Measuring errors of amplitude and phase for vibratory accelerations when testing objects

Measurement Techniques -     

DRYING OF GRANULAR PARTICLES IN A MULTISTAGE INCLINED FLUIDIZED BED WITH MECHANICAL VIBRATION

A mathematical model for the drying rate of granular particles in a multistage inclined fluidized bed(IFB) is presented from the standpoint of simultaneous heat and mass transfer, with taking the effect of mechanical vibration added vertically into consideration.

Steady-state distributions for the temperatures and concentrations of the particles and the heating gas, and for the moisture content of the particles are numerically calculated based on the present model. The calculated results show fairly good agreement with the experimental data, which were obtained from the drying experiments of brick particles in a three-stage IFB using comparatively low temperature air(40-60°C) as the heating gas.

It has been found within the range of the experimental conditions employed that, the mechanical vibration added vertically enhances the over-all drying rate of the particles and its effect can be considered equivalent to an increase in the air velocity.     

Effect of nitrogen ion implantation on impact wear

The effect of nitrogen ion implantation on the impact wear of several metals and alloys with different hardnesses was studied. An impact testing machine was built for this study. In this machine, bullet-shaped projectiles are bounced against a metal surface which is either stationary or rotating. Wear was determined by weight loss measurements. Scanning electron microscopy pictures were taken to study the surface damage. It was found that nitrogen ion implantation improved the impact wear of most of the materials studied. With sliding motion added during the impact, nitrogen ion implantation has little effect.     

On liquid motion in a circular cylinder with horizontal axis

Summary The flow pattern of the slosh motion of a homogeneous, nonviscous (inviscid) and incompressible fluid with a free surface, contained in a rigid circular canal, has been dealt with analytically and experimentally. The axis of the canal is perpendicular to the direction of gravity. Considered are transverse (lateral to axis) oscillations of the liquid. The shape of the free liquid surface is determined numerically by means of a simple procedure. Theoretically calculated streamlines (path lines) are found to be in good qualitative agreement with experimentally observed trajectories of small spheres, made of plastic material and immersed in the liquid. The plastic particles and the liquid (water with a solution of salt added) have the same density.     

An analytical reflection and emission UHV surface electron microscope

An UHV surface electron microscope is described which allows the study of surfaces under vacuum conditions common in surface science with the following techniques: LEERM; LEED; photo, thermionic, secondary emission microscopy; absolute micro area work function measurements. In particular, the first LEERM of Mo(110) and Si(111) surfaces are presented. They show monoatomic steps with high contrast due to Fresnel diffraction and structural differences, respectively. Condensed silver crystallites are imaged. Gold adsorption layers on Si(111) show strong contrast in photoemission; the layer thickness is deduced from LEED.     

Type synthesis of spatial mechanisms on the basis of spatial single loop structural groupsTypensynthese räumlicher mechanismen auf der grundlage räumlicher einfach geschlossener strukturgruppen

This paper describes the basis for a new method of type synthesis of spatial mechanisms with the use of single-loop structural groups having zero degrees of freedom. Applying the binary system, the value 0 is used for R (revolute) and 1 is used for P (prismatic) pairs. The five-link spatial groups are described by codes both in the binary and decimal systems. All other groups are reduced to the basis of five-link spatial groups. In these cases two-degree-of-freedom and three-degree-of-freedom kinematic pairs are transformed to one-degree-of-freedom pairs, and these transformations are also described by codes in the binary and decimal systems. This method of coding can be programmed for digital computation and applied towards the automatic type synthesis in the design of spatial mechanisms. The system is equally clear for alphanumeric or for graphical display. To the designer it defines the diagram of the mechanism, pointing out the frame, the mobile links, the types of the kinematic pairs and their mutual disposition in the mechanism configuration.