A mathematical model of sorption of Zirconium and Hafnium cations mixture and elution of these ions from a cation exchange resin bed is developed. Sulfuric acid is selected as the eluent for selective separation of Zr and Hf in a packed bed of Dowex cation exchange resin. The column model is a dispersed plug flow model,and assumed to consist of randomly packed synthetic and spherical resin ...

OBJECTIVE Obstructive sleep apnea (OSA) has been shown to affect the quality of life (QOL) in patients, and QOL improves after treatment with nasal continuous positive airway pressure (CPAP). However, the effects on the bed partner of the patient with OSA have received little attention. We studied QOL in patients with OSA and their bed partners, and the effect of CPAP therapy on QOL. DESIGN F...

Little is known about the potential for acoustic communication in bed bugs, Cimex lectularius L. (Hemiptera: Cimicidae), or the use of sound as cues in host location, although many hemipterans are known to communicate with sound. Most behavioral research has focused on bed bug pheromones that are used in aggregation and as alarm signals. We investigated the influence of sound as a deterrent and...

We tested a threshold-based bed bug (Cimex lectularius L.) management approach with the goal of achieving elimination with minimal or no insecticide application. Thirty-two bed bug infested apartments were identified. These apartments were divided into four treatment groups based on apartment size and initial bed bug count, obtained through a combination of visual inspection and bed bug monitor...

Determining the evolution of the bed of a river or channel due to the transport of sediment was first examined in a theoretical context by Exner in 1925. In his work, Exner presents a simplified bed evolution model derived from the conservation of fluid mass and an “erosion” equation that is commonly referred to as the sediment continuity or Exner equation. Given that Exner’s model takes the fo...

Rhodoliths are unattached calcareous red algae that form extensive beds. Although rhodolith beds are widely distributed in temperate and tropical areas, a recent discovery in the North Pacific Ocean represents a significant northward extension of known rhodolith distribution. This bed, located in Prince William Sound, Alaska, is composed of one rhodolith species, Phymatolithon calcareum, with t...

The objective of this study was to (1) to determine the contribution of moderate sun bed exposure to serum 25(OH)D(3) levels; (2) to estimate the decay time of a high 25(OH)D(3) level obtained by sun bed exposure; and (3) to evaluate if the recommended ingestion of vitamin D is sufficient to maintain the 25(OH)D(3) concentration obtained by sun bed exposure. Ten volunteers (20-35 y.o.), skin ty...

The geometry of a river bed surface is determined by the arrangement and size of the particles that form the bed. In gravel-to-boulder bed rivers, the surface geometry around any individual particle may be complex and highly variable, and tends to include multiparticle structures. These textural and structural characteristics influence whether an individual particle is entrained. The effect on ...

Beryllium, in its pebble form, has been proposed in various blanket concepts to serve different purposes. Thermal property data for such a heterogeneous packed bed is needed, particularly data on the impact of compression forces on its magnitude and consequent temperature profile. The objectives of this work are to obtain and quantify experimental data on the effective thermal conductivity of a...