The Glass Powders’ Dispersion Effect on the Glass-Reinforced Concrete Performance Properties

The influence of the glass powder dispersion and its amount on the operational properties of glass-reinforced concrete is investigated. Box and plate glasses, which were crushed and ground in a ball mill, were used as the starting material. Portland cement manufactured by Serebryakovcement, a brand of CEM IIA 42.5N, was used as a binder. The developed technology for the glass-reinforced concrete manufacturing provided at the final stage for a joint grinding of Portland cement and glass powder. At the same time, the specific surface area of ​​Portland cement increased from 3200 to 6500 cm2/g. The optimum amount of fine glass powder in glass-reinforced concrete is established. It is shown that at the content of 30 wt.% glass powder with a dispersion of 5872 cm2/g the glass-reinforced concrete density is 1915 kg/m3 and the compressive strength is 45.09 MPa. When superplasticizer is introduced into glass concrete, a synergistic effect is observed, as a result of which the compressive strength increases to 50.88 MPa. Using the synchronous thermal analysis, the effect of finely dispersed glass powder on phase transformations in glass-reinforced concrete under non-isothermal heating conditions was studied. It was shown that the processes of ettringite dehydration in glass-reinforced concrete are shifted to the region of high temperatures, and the processes of calcium hydro silicates dehydration and calcite destruction are shifted to lower temperatures.

Tin Powders Electrodeposition from Choline Chloride Based Ionic Liquid

Possibilities of tin powders obtainment from the choline chloride-ethylene glycol ionic liquid are considered. The tin reduction from an ionic liquid mechanism is confirmed via chronovoltametry, chronopotentiometry, transient potential and impedance spectroscopy methods. Said mechanism includes the trichlorostanite complexes reduction at current densities up to 5 mA / cm2, recovery from a polyanionic adsorbed layer at current densities of 5-12 mA/cm2 and recovery from a mixed layer including polyanions bound and by electrolyte ions at current densities exceeding 12 mA/cm2. Tin ions reduction from the mixed coating layer facilitates forming of encapsulated tin powder particles with shape of symmetrical dendrites. Powders obtainment from an ionic liquid allows to reduce the resulting powder dispersion.

Method for nano-powder dispersion degree definition

Relying upon Stokes Law there was offered a way for the definition of nano-powder dispersion on measuring a speed of its sedimentation from powder slurry in water. Way is to construct differential nanopowder’s particles distribution curve of by fractions to determine their main size.

Surface contamination of counting tools after mock dispensing of cyclophosphamide in a simulated outpatient pharmacy

Purpose The primary aim was to determine if dispensing of cyclophosphamide tablets resulted in accumulated residue on pharmacy counting tools during a simulated outpatient dispensing process. Secondary objectives included determining if cyclophosphamide contamination exceeded a defined threshold level of 1 ng/cm2 and if a larger number of prescriptions dispensed resulted in increased contamination. Methods Mock prescriptions of 40 cyclophosphamide 50 mg tablets were counted on clean trays in three scenarios using a simulated outpatient pharmacy after assaying five cleaned trays as controls. The three scenarios consisted of five simulated dispensings of one, three, or six prescriptions dispensed per scenario. Wipe samples of trays and spatulas were collected and assayed for all trays, including the five clean trays used as controls. Contamination was defined as an assayed cyclophosphamide level at or above 0.001 ng/cm2 and levels above 1 ng/cm2 were considered sufficient to cause risk of human uptake. Mean contamination for each scenario was calculated and compared using one-way analysis of variance. P-values of < 0.05 implied significance. Results Mean cyclophosphamide contamination on trays used to count one, three, and six cyclophosphamide prescriptions was 0.51 ± 0.10 (p=0.0003), 1.02 ± 0.10 (p < 0.0001), and 1.82 ± 0.10 ng/cm2 (p < 0.0001), respectively. Control trays did not show detectable cyclophosphamide contamination. Increasing the number of prescriptions dispensed from 1 to 3, 1 to 6, and 3 to 6 counts increased contamination by 0.51 ± 0.15 (p = 0.0140), 1.31 + 0.15 (p < 0.0001), and 0.80 ± 0.15 ng/cm2 (p = 0.0004), respectively. Conclusion Dispensing one or more prescriptions of 40 cyclophosphamide 50 mg tablets contaminates pharmacy counting tools, and an increased number of prescriptions dispensed correlates with increased level of contamination. Counting out three or more prescriptions leads to trays having contamination that surpasses the threshold at which worker exposure may be increased. Pharmacies should consider devoting a separate tray to cyclophosphamide tablets, as cross-contamination could occur with other drugs and the efficacy of decontamination methods is unclear. Employee exposure could be minimized with the use of personal protective equipment, environmental controls, and cleaning trays between uses. Future investigation should assess the extent of drug powder dispersion, the effects of various cleaning methods, and the potential extent of contamination with different oral cytotoxic drugs.