Analysis of Boron in Borosilicate Glasses by Neutron Transmission

A rapid method for the determination of boron in borosilicate glasses by neutron transmission has been developed. The glass sample is dissolved in 48% HF, placed in a polyethylene cell which is located near a Ra-Be neutron source. The neutron source and sample cell are embedded in a parafEn moderator. The attenuation of the neutron flux, which can be related to the boron concentration in the cell, is monitored with a BF₃ enriched B¹⁰ proportional counter. Boron determinations can be made in approximately 40 minutes with an accuracy of ±%. Owing to the low sensitivity (approximately 1 mg.) the major disadvantage of the method is the large sample size necessary. The method, however, is well suited for use as a quality control procedure.     

SELECTING DEFORMATION RATES IN TEXTURE TESTS *

Abstract . Since mastication involves high deformation rates (150cm min^?1), the arbitrarily selected slow deformation rates usually used in instrumental texture tests can lead to erroneous results and lack of correlation with sensory evaluation with respect to the order of sample ranking. Sophisticated instrumentation that is costly to operate is required to accurately simulate the deformation rates operating in the mouth. It is suggested that instrumental data obtained at slow rates could be evaluated in a more meaningful manner if series of similar samples were tested at increasing deformation rates and the plotted force/deformation curves extrapolated to 150cm min^?1. It is implied that recording systems would be more useful, if in addition to force, they sensed the rate of force change with deformation rate.     

MEASUREMENT OR PEA,TENDERNESS II: A Review of Methods*

Abstract. Different methods used to measure pea tenderness are reviewed. Objective estimation of crop maturity, pea tenderness and quality has concerned researchers for many years. Chemical and mechanical methods have been used, and several instruments developed. There is a high degree of correlation between methods which also appear to agree with sensory analysis. For grading peas to establish the price paid to the grower, accuracy and economy under commercial conditions is of prime importance. Some methods are unsuitable on this basis, and presently used instruments and the manner in which they are operated require improvement.     

CRITERIA USED BY RESEARCH AND DEVELOPMENT ENGINEERS IN THE SELECTION OF AN INFORMATION SOURCE.

INVESTIGATED THE CRITERIA EMPLOYED BY ENGINEERS IN THE SELECTION OF VARIOUS TECHNICAL INFORMATION CHANNELS IN PROBLEM-SOLVING ENDEAVORS. FOCUSES ON THE RELATIONSHIPS OF CERTAIN CRITERIA IDENTIFIED IN PAST RESEARCH TO SUCH FACTORS AS FREQUENCY OF CHANNEL UTILIZATION AND THE RATE AT WHICH ENGINEERS ACCEPT OR REJECT TECHNICAL INFORMATION RECEIVED FROM SPECIFIC CHANNELS. A DIRECT RELATIONSHIP IS FOUND BETWEEN PERCEIVED ACCESSIBILITY OF INFORMATION CHANNELS AND SEVERAL OBJECTIVE MEASURES OF UTILIZATION, WHEREAS NO DEFINITE SUPPORT IS FOUND FOR THE HYPOTHESIS THAT THE CHANNELS PERCEIVED HIGHEST IN TECHNICAL QUALITY ARE THOSE USED MOST FREQUENTLY. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

VISUAL IMAGERY AND SUSCEPTIBILITY TO HYPNOSIS.

MEASURED VISUAL IMAGERY UNDER SENSORY RESTRICTION AND UNDER RHYTHMIC PHOTIC STIMULATION TO TEST THE HYPOTHESIS THAT HIGH VISUAL-IMAGERY INDIVIDUALS WOULD BE MORE SUSCEPTIBLE TO HYPNOSIS. SUPPORT FOR THE HYPOTHESIS WAS OBTAINED PRIMARILY FROM IMAGERY MEASURES THAT INSTRUCTED 784 STUDENTS TO TRY TO SEE CERTAIN SPECIFIED IMAGES. LITTLE SUPPORT WAS OBTAINED USING LESS PRESCRIPTIVE MEASURES TAPPING FREE, SPONTANEOUS IMAGERY. THE DIMENSIONS OF IMAGERY AND POSSIBLE SEX DIFFERENCES IN VISUAL IMAGERY WERE STUDIED. (29 REF.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

DETERMINATION of RESIDENCE TIME DISTRIBUTION of NONSETTLING FOOD PARTICLES IN VISCOUS FOOD CARRIER FLUIDS USING HALL EFFECT SENSORS

Hall effect sensors were used to determine residence time distributions for diced carrot particles in 4% Colflo 67 carrier fluid. Four sensors at either end of a 3.2 m long 2 in. IDF tube viscometer allowed residence times to be measured for carrot particles incorporating a ceramic magnet. Mean particle residence times were greater than mean bulk residence time for 8 mm diced carrots, whereas 15 mm carrots showed trials in which particles travelled faster than the bulk fluid. Increasing concentration of 15 mm diced carrots from 3.25, 6.30, 9.16 to 11.85% w/w resulted in decreasing mean particle residence times from 17.6, 17.0, 15.9 to 14.3 s, with minimum residence times of 16.4, 16.2, 14.8 and 13.4 s, respectively. This sensing technique operates through stainless steel, providing applications for UHT foods containing particles. In addition, the technique was not affected by high particle concentration, and will operate for any distribution of particle size, shape or type.     

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.     

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.     

Imaging applications of synchrotron X-ray phase-contrast microtomography in biological morphology and biomaterials science. I. General aspects of the technique and its advantages in the analysis of millimetre-sized arthropod structure

Synchrotron‐generated X‐rays provide scientists with a multitude of investigative techniques well suited for the analysis of the composition and structure of all types of materials and specimens. Here, we describe the properties of synchrotron‐generated X‐rays and the advantages that they provide for qualitative morphological research of millimetre‐sized biological organisms and biomaterials. Case studies of the anatomy of insect heads, of whole microarthropods and of the three‐dimensional reconstruction of the cuticular tendons of jumping beetles, all performed at the beamline ID19 of the European Synchrotron Radiation Facility (ESRF), are presented to illustrate the techniques of phase‐contrast tomography available for anatomical and structural investigations. Various sample preparation techniques are described and compared and experimental settings that we have found to be particularly successful are given. On comparing the strengths and weaknesses of the technique with traditional histological thin sectioning, we conclude that synchrotron radiation microtomography has a great potential in biological microanatomy.