Ultrasonic modification of carbonate scale electrochemically deposited in tap water.

Influence of the ultrasound intensity (28 kHz, 1.1-7.5 W/cm2) on CaCO3 nucleation-growth on the surface of a cylinder mild steel electrode rotating at 500 rpm was studied in tap water. The deposition kinetics was analyzed by chronoamperometry; the calcareous layer was characterized by gravimetry, scanning electron microscopy and XRD. Application of ultrasound to calcium carbonate crystallization affects nucleation site density, mass-transport rate and cavitation erosion of the deposits. Lower intensity ultrasound reduces scale porosity and area density by increasing nucleation site density and accelerating the mass transport. Higher intensity ultrasound promotes cavitation erosion of the formed layer, thus cleaning the surface from the scale. A scale layer with the highest blocking properties formed under applied ultrasound intensity of 1.9 W/cm2. The ultrasound doubled crystallization rate, reduced the scale porosity 5 times and halved its area density compared to non-sonicated conditions. Ultrasound of controllable intensity can solve both scale and corrosion problems of industrial heat-exchange equipment by forming a protective scale layer and removing excessive deposits.

Geographical differences in survival of dogs with non-Hodgkin lymphoma treated with a CHOP based chemotherapy protocol.

BACKGROUND: In humans geographical differences in the incidence and presentation of various cancers have been reported. However, much of this information has not been collected in veterinary oncology. AIM: The purpose of this study was to determine if a geographic difference in progression free survival exists for dogs with lymphoma treated within the US. MATERIALS AND METHODS: Medical records of 775 cases of canine lymphoma from 3 US regions (west, south and north), treated with CHOP chemotherapy, were retrospectively evaluated. Cases were collected from referral institutions and were required to have received at least one doxorubicin treatment and have follow up information regarding time to progression. RESULTS: Significant differences in sex (p = 0.05), weight (p = 0.049), stage (p < 0.001), immunophenotype (p = <0.001), and number of doxorubicin doses (p = 0.001) were seen between regions. Upon univariate analysis, progression free survival (PFS) differed by region (p = 0.006), stage (p = 0.009), sub-stage (p = 0.0005), and immunophenotype (p = 0.001). A multivariable Cox regression model showed that dogs in the western region had a significantly shorter PFS when compared to the south and east. CONCLUSION: PFS was significantly affected by stage, sub-stage and phenotype.