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.     

Carbonates in Silver Solution

A procedure has been established for applying the Jenkins alternating bend test to nickel deposits to determine the freedom of the solution from deleterious contaminants. Certain impurities in the solution have been found markedly to reduce the resistance of the deposit to bending, although without appreciable influence on either appearance or hardness. The practical value of the method in the routine examination of nickel solutions has been indicated.     

Fracture Toughness of Veneering Ceramics for Fused to Metal (PFM) and Zirconia Dental Restorative Materials

Veneering ceramics designed to be used with modern zirconia framework restorations have been reported to fracture occasionally in vivo. The fracture toughness of such veneering ceramics was measured and compared to that of conventional feldspathic porcelain veneering ceramics for metal framework restorations. The fracture toughness of the leucite free veneer was measured to be 0.73 MPa m ± 0.02 MPa m, which is less than that for the porcelain fused to metal (PFM) veneering ceramic: 1.10 MPa ± 0.2 MPa. (Uncertainties are one standard deviation unless otherwise noted.) The surface crack in flexure (SCF) method was suitable for both materials, but precrack identification was difficult for the leucite containing feldspathic porcelain PFM veneer.