Styrofoam Container Research Articles

Comparative Evaluation of Containers Used as Honey Bee Hives for Disposable Pollination Units12

Severa1 types of containers that might be used as temporary hives for package-sized units of Apis mellifera L. for short-term crop pollination were screened for suitability, bee acceptance, and effect on bee foraging activities. Disposable temporary pollination units (DPU’s) also were compared with package colonies of equal population in single 12-frame 6-5/8-in deep hives. Styrofoam containers appeared to be the most suitable and compared favorably with the colonies in respect to frequency of absconding, levels of mortality, and overall development. However, the package colonies had greater flight activity and a greater total percentage of foraging bees compared with the DPU’s. A near absence of pollen collection by bees in the DPU’s resulted in a proportionally greater number of nectar collecting and nonforaging bees compared with the colonies.

Scattering by Two-Component Random Distributions of Spheres

Theory and prototype (at wavelength lambda = 5 mm) partial coherence scattering data for optical applications in diagnostic measurements on two component suspensions or gases are presented. Results are given for equal volume mixtures of two sizes of moving randomly distributed large spheres for all realizable values of the fractional volume w (the fraction of the slab region container filled by scattering material). The relative index of refraction of the spheres was about 1.017, and their diameters were 6.52lambda and 3.33lambda (so that we used about eight times as many small spheres as large ones for each value of w). The spheres were of lightweight Styrofoam, and their motion arose from turbulent air streams (flowing through grids that form the top and bottom of a Styrofoam container), and the data were obtained in real time by processing the instantaneous phase quadrature components of the scattered field with an electronic analog computer. We give results for the forward scattered coherent phase, for the coherent, incoherent, and total intensities, and for the covariant magnitude and phase which (together with the incoherent intensity) provide the variances and covariance of the instantaneous phase quadrature components. We also consider certain reduced data records (from which the major effects of scatterer size and material have been eliminated) to indicate the dependence of the scattering on the fractional volume and to facilitate comparison with earlier data for distributions of identical spheres.

Comparison of distribution functions from scattering data on different sets of spheres

We compare certain reduced data records for scattering of 5-mm electromagnetic waves by two sets of Styrofoam spheres of different diameter, moving randomly within a slab-region Styrofoam container. For the small spheres we summarize raw measurements for the forward scattered coherent phase, for the average intensities, and for the variances and covariance of phase-quadrature components of the instantaneous field; analogous results for the large spheres were given previously [1]. The emphasis is on the relative behavior of the two sets of reduced data records obtained by using scattering theory to eliminate sphere size, etc., from the original data. In particular, we compare appropriate, reduced data with statistical mechanics approximations for the hard sphere in order to delineate differences, and to indicate that the analytical procedures developed for the dynamical gas model may be applied to isolate the analogous functions for naturally occurring distributions.

Scattering by random distribution of spheres vs. concentration

We give data and theory for scattering of 5-mm waves by Styrofoam spheres moving randomly within a slab region Styrofoam container. The results summarize two systematic programs of measurements for the forward scattered coherent phase, the average intensities (coherent, incoherent, and total), and for the variances and covariance of phase-quadrature components of the instantaneous field. These were obtained separately and simultaneously vs. the number ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</tex> ) of spheres in the container for concentrations corresponding to sparse gases through dense gases, on to the limiting case of an amorphous solid. Two relatively distinct "compression processes" for which the coherent phase increased linearly with increasing <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</tex> were studied: the amplitude of the covariance was either as large or as small as we could obtain. The data records for the small case are in relatively good accord with computations; those for the large show departures in the direction indicated by qualitative considerations of the effects of clumping.

Uncontrolled and controlled rate freezing of human kidney cell suspension

Human embryonic, fetal, or neonatal (within 48 hrs after birth) kidneys were processed by enzymatic digestion and frozen as primary suspensions. Sixty suspensions were frozen by wrapping the 16-mm screwcap test tubes with cotton, sealing them in a styrofoam container, and placing the container directly into liquid nitrogen vapor. During the same time period, 100 suspensions were frozen at a controlled rate using the Linde BF 3-2 freezing apparatus (−1°C per min from 0°C to −30°C and −10°C per min to −150°C) and stored in liquid nitrogen vapor. Test cultures were reconstituted within 2 months after freezing and again at various intervals ranging from 1 month to 2 years. The relative merits of the two methods were evaluated with respect to number of days to culture confluency. A comparison also was made between the number of prefreeze and postfreeze days to confluency. The results showed that there was only a small difference between the number of days to confluency (8.7 days for the uncontrolled freezing as compared to 9.1 days for the controlled) when tested within 2 months. However, upon more prolonged storage, the number of days to confluency in the uncontrolled frozen suspensions increased substantially as compared with the controlled. There was an average increase of 2.3 days to confluency between the postfreeze and prefreeze cultures.

Scattered Intensities for Random Distributions—Microwave Data and Optical Applications

We compare theory and microwave intensity measurements (5-mm wavelength) on a dynamical model of a compressible gas. The model consists of a slab-region styrofoam container (25cm × 50 cm × 60 cm) whose top and bottom are grids which allowfor the passage of turbulent air streams, but serve to confine light-weight randomly moving spheres (3.45-cm diam, relative index of refraction of 1.016 at 5-mm wavelength). We varied the number (N) of scatterers in the container (fractional volume w in the central region ranging from about 0.03 to 0.3), and made measurements in the forward direction (θ = 0), as well as at off-forward angles in the range θ = 0° to 15°, and θ = 30° to 80°. The essential limitations on the general utility of our data are set by difficulties in relating w to N, and by the supplementary statistical procedures used to reduce our chart records of instantaneous total intensity data into coherent and incoherent components. For most parts of the program, the accord between numerical computations based on theory and our specific measurements is adequate, and the general predictions of theory are satisfactorily substantiated, e.g., that for gaslike distributions of lossless large scatterers the incoherent intensity divided by the departure of the coherent intensity from the forward intensity in the absence of scatterers is practically independent of concentration.