ANALYSIS OF UNSTABLE BEHAVIOR OF PNEUMATIC CONVEYING SYSTEMS

The unstable conveying zone has been recognized by many authors in their attempts to define the minimum conveying velocitv on the dilute phase side of this zone. It was found that the gas flow rate influences the magnitude and frequency of the pressure fluctuations experienced during this type of flow. Generally a reduction of gas flow rate will reduce both the intensity and frequency of the fluctuations.

During the measurement of data for the previous experiments, it was recognized that the pressure fluctuations of dilute and strand flow can serve as simple indicators of the flow stability. An analysis of these fluctuations is presented, which suggests that simple statistical factors can be used to estimate the system condition of operation with respect to the pressure minimum or unstable zone. These elementary trends in the data can be useful for one attempting to optimize a system. This analysis lead to a more intensive approach using Hurst's rescaled range analysis, to examine the changes in pressure fluctuations, which occur when a system undergoes a simulated optimization procedure. The analysis suggested that Hurst's exponent may be used as an indicator of the onset of instability.     

Safety and tolerability of intravenous ferric carboxymaltose in patients with iron deficiency anemia

There is limited safety information about ferric carboxymaltose (FCM), a new intravenous iron preparation. This randomized, crossover study compared the safety and tolerability of double-blinded intravenous doses of FCM or placebo in patients with iron deficiency anemia. Subjects (559) with iron deficiency anemia received a dose of either FCM (15 mg/kg, maximum 1000 mg) over 15 minutes or placebo on day 0. On day 7, subjects received the other agent. Safety evaluations were performed on days 7 and 14. The primary endpoint was the incidence of treatment-emergent adverse events during each 7-day study period. During the first 24 hours and during the 7-day treatment period, at least one treatment-emergent adverse event was experienced by 15.0% and 29.3% of subjects after FCM and 11.4% and 19.7% after placebo, respectively. Most were classified as Grade 1 or 2. Six subjects had Grade 3 treatment-emergent adverse events after FCM and 9 subjects after placebo. One subject had a Grade 4, and 1 subject had a Grade 5 treatment-emergent adverse event, but neither was considered study drug-related. During the first 24 hours of the treatment period, drug-related adverse events were reported in 9.3% of subjects receiving FCM and 4.8% receiving placebo. Of drug-related Grade 3 events, 4 subjects received FCM and 5 subjects received placebo. Administration of FCM (15 mg/kg, maximum of 1000 mg) over 15 minutes was well tolerated and associated with minimal risk of adverse reactions in patients with iron deficiency anemia.     

Dynamic tensile strength of polyurea-bonded steel/E-glass composite joints

The dynamic tensile strengths of E-glass composite/polyurea and polyurea/steel interfaces within the E-glass composite/polyurea/AL-6XN stainless steel joint were measured using a laser spallation technique. Values of 370?±?20?MPa were obtained for the polyurea/composite interface while a much higher value of 486?±?20?MPa was obtained for the steel/polyurea interface. Because of the transient nature of the stress pulse, the strain rate changes continuously as the interface stress builds up. A peak strain rate of 5?×?10⁵?s^?1 was estimated. The effect of moisture on the tensile strength of the E-glass/polyurea interface was also examined. The effect was found to be minimal, with the tensile strength stabilizing at 320?±?25?MPa after 30?days of exposure to a 90%RH, 50?°C environment. When comparing the strengths of corresponding interfaces in an epoxy-bonded joint from a previous study, it was concluded that polyurea results in a much stronger and durable joint.