Phase Behavior and Mechanical Properties of TripaImitin/Butterfat Mixtures

The functionality of butterfat can be improved by fractionation, a process that can be considered as enrichment of butterfat with long-chain saturated fatty acids. Model hard fractions were produced by adding tripalmitin to butterfat, in ratios from 0.9:0.1 through 0.1:0.9. The model system had very similar thermal behavior and mechanical properties to true fractions. The phase behavior of tripalmitin/butterfat mixtures was determined. Such butterfat fractions have potential as a moisture barrier in edible films and coatings. Tripalmitin-enriched butterfat is an alternative to hard butterfat fractions in some applications.     

Preparation and Properties of Monodispersed Colloidal Particles of Lanthanide Compounds: III, Yttrium(III) and Mixed Yttrium(III)/Cerium(III) Systems

Colloidal dispersions of uniform spherical particles of yttrium basic carbonate and rodlike particles of yttrium ammine carbonate were prepared by aging at elevated temperatures yttrium salt solutions in the presence of urea. Different composition and morphology were achieved by altering the aging temperature and time. Coprecipitation in mixed solutions of yttrium(III) and cerium(III) salts under similar experimental conditions yielded composite spherical particles of basic carbonate. The content of the two metals in the solids followed closely the initial composition of the reacting solutions. On calcination all prepared solids converted to their corresponding oxides while retaining their particle morphology. The so-prepared powders were characterized by various techniques.     

On the Fracture of Glass Which Is Subjected to Slowly Increasing Stress

A single number called the "strength" does not serve to describe adequately the fracture properties of glass subjected to a slowly increasing tensile stress. Instead, it is found that the surface where fracture originates may be represented as a continuum over which flaws of differing "critical breaking stresses" are distributed. The distribution function for the flaws is given by S σ where σ is the tensile stress initiating fracture and S and b are constants which are properties of the surface for slowly increasing stresses. The testing procedure and nature of the flaws are discussed.     

Private Enterprise in Eclipse? A Reassessment of British Housing Policy in the 1940s

Conventional analyses of housing policy in most European countries treat the 1940s as a decade when private enterprise was eclipsed by social housing programmes. As a result, private enterprise is also eclipsed in most accounts of housing and housing policy in the early post-war period. This paper draws on the British experience to show that if the policy narrative is traced from wartime plans rather than from post-war action, and if the question of who actually built post-war social housing is raised, then a different picture emerges. From the middle of 1942 British civil servants and ministers were engaged in detailed planning for post-war housing, in both the short and long term. Private enterprise was assumed to have a major role to play in the long term, and a supporting role in the transitional period. In practice the post-war Labour Government relied on local authorities as housing developers, who themselves relied on private contractors to build the houses. The eclipse of private enterprise was, therefore, more apparent than real.     

Effect of Air Flow and Acceleration on Particle Size of Dry Powder Aerosols determined by Time-of-Flight Aerosol Beam Spectrometry

ABSTRACT

The effect of air flow and acceleration on the particle size distributions of two Turbuhalers containing drug loads of 0.5 and 1.3 mg per dose was determined with a time-of-flight aerosol beam spectrometer (Aerosizer®). While the particle size of both inhalers decreased with increasing flow and acceleration, the distributions became narrower and variability was reduced. Simultaneously, a decrease in the number and mass of particles measured was observed which was more pronounced for the 1.3 mg dose. Additionally the count rate for the 1.3 mg dose was lower than for 0.5 mg. These observations were accompanied by a remarkably fine particle size distribution for the high dose Turbuhaler®. It was concluded that the quantity of particles in the DPI aerosols exceeded the resolution of the Aerosizer, erroneously shifting the size distributions towards smaller diameters.

In addition, the DPI aerosols were analyzed with a Four Stage Impinger to evaluate the results. The particle size estimates obtained using the impinger were in the same range as those obtained at an acceleration of 5 L/s2 using the Aerosizer to study the 0.5 mg Turbuhaler. The Aerosizer produced significantly smaller particle sizes than the impinger in all cases evaluating the 1.3 mg Turbuhaler, supporting the theory of distorted particle size distributions due to particle overload.