Accurate determination of the mean relative humidity in controlled climates at high humidities (new method)

The measurement of the relative humidity (RH) at high levels to the desired accuracy is still a problem, especially for levels above 90% RH. The reasons for this are:

• i The accuracy of the standard apparatus is lower at high RH than at moderate and low RH;
• ii The need for accurate measurement of the RH in moisture controlled rooms is greater at high RH than at lower RH, because for moisture sensitive products, such as fibreboard boxes and certain horticultural products, the influence of a minor deviation in RH on the properties of these products is considerably greater at high RH than at moderate and low RH.

     

Seven-pinhole tomography of the thyroid

In this paper we introduce a new application of the sevenpinhole (7P) collimator: tomographic imaging of the thyroid. The collimator design has been reoptimized for this particular application by diminishing the distance from the collimator plate to the crystal and by choosing a smaller pinhole diameter. To reconstruct thyroid images from the two-dimensional projection data we use a method which we developed for 7P tomographic imaging of the heart [1]. Phantom experiments and patient studies demonstrate that this new device is capable of producing tomographic images of good quality and high resolution. Therefore, it seems to offer a promising alternative to conventional planar imaging of the thyroid (using a single-pinhole collimator).     

Beam profile measurement of a solar-pumped iodine laser

Beam profile measurements have been made as a function of time within the laser pulse and C2F5I pressure. Measurements indicate that the profile is determined directly by the optical excitation volume, produced by the solar simulator, and that media distortion plays a minor role compared to the build up of quenching species during the lasing pulse.     

Site occupations and ordering behaviour of O phase in Ti2AlNb—based intermetallics

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｏｒｔｈｏｒｈｏｍｂｉｃａｌｌｏｙｓａｒｅｏｆｇｒｅａｔｔｅｃｈ ｎｏｌｏｇ ｉｃａｌｉｎｔｅｒｅｓｔｉｎｈｉｇｈｔｅｍｐｅｒａｔｕｒｅａｐｐｌｉｃａｔｉｏｎｓｓｉｎｃｅｔｈｅｙｈａｖｅａｇｏｏｄｂａｌａｎｃｅａｍｏｎｇｓｔ     

The role of consultant engineers on personnel training and desalination plant operation

The raising countries asking for desalination plants are 0.011:0 normally in trouble for the period of time between taking over of the plant and the first two years of operation.During this period it is very useful to use proper consultants to supervise plant operation and train operating, maintenance and management personnel.In the present paper appropriate schemes of cooperation are outlined togheter with a particullary idea about plant operation control.     

Elongational viscosity of microbead suspensions

A ‘tubeless syphon’ was used as an elongational viscometer for the purpose of measuring elongational viscosities of glass bead suspensions in dilute polymer solutions. It was found that while the shear viscosities increased, the elongational viscosities decreased very sharply with increasing bead concentration. The conclusions from the present data are then compared with the observed changes in the elastic properties of two phase molten polymer systems. A double shift procedure has been successfully adopted to correlate the experimental data.     

Processing and Properties of Particulate Composites from Coated Powders

A method is described for sintering of highly loaded (≤20 vol%) alumina matrix/silicon carbide whisker or platelet composites to closed porosity. The method uses controlled heterogeneous precipitation in a suspension of whiskers or platelets. The suspension-coated particles are calcined to produce a free-flowing composite powder which can be hot-pressed or free-sintered to high density. The results of consolidation and mechanical property testing are reported.     

Non-markovian diffusion processes in polymers and a stretched exponential relaxation constitutive equation

Non-Markovian diffusion transport in polymers was studied. Applying the results of various researchers, a stretched exponential relaxation function was obtained and a linear viscoelastic constitutive equation formulated. Frequency dependent material functions, obtained from this constitutive equation were studied and the results successfully compared with experimental data for polyethylene oxide solutions. Sorption kinetics in a polymeric film were also studied. © 1994 John Wiley & Sons, Inc.     

Acid cleaning and passivation of power plant condensers and desalination plants

Experiences of acid cleaning and passivation treatments of copper alloy tubes are described. The suitability of corrosion monitoring to follow each step of such operation is demonstrated.