Design of Saturistors for Induction Motor Speed Control

A design method is described for a saturistor which enables the stall current of an induction motor to be restricted to some predetermined value without significant effect on the full-load operation. The design method requires knowledge of the dynamic B?H loop for the hard magnetic saturistor material. With controlled sinusoidal primary supply voltage and the saturistor connected in the secondary circuit, increased torque at reduced current was obtained during stall.     

Radioprotectant Activity of 5-Diethylsulfonamoylsalicylatocopper(II) in Gamma Irradiated Mice

Survival and changes in mean body mass of whole-body irradiated mice were determined to examine the radioprotectant activity of 5-diethylsulfonamoylsalicylatocopper(II) [Cu(II) (5-DESS)]. One of four groups of 25 female C57BL/6 mice were treated subcutaneously (sc)with 0, 10, 20, 40, 60, 80, 100, or 120 mumol Cu(II)(5- DESS)/kg of body mass 3 hours before exposure to 8.0 Gy, gamma irradiation. In this paradigm, doses of Cu(II)(5- DESS) increased survival up to 92% above vehicle-treated control mice (P = 0.008). Mean body mass determinations revealed that mice treated with 80 to 120 mumol Cu(II)(5-DESS)/kg of body mass exhibited a smaller decrease in body mass than other complex-treated groups. These results support the hypothesis that Cu(II)(5-DESS) is an effective radioprotectant.     

Sexually Mature Cuttlefish are Attracted to the Eggs of Conspecifics

Cuttlefish typically are solitary, but form aggregations to spawn. We tested the hypothesis that bioactive factors in the eggs of conspecifics may facilitate the formation of spawning groups of Sepia officinalis. Cuttlefish detected odors from cuttlefish eggs, resulting in an increased ventilation rate. Extracts from female ovaries induced the largest increase in ventilation rate, suggesting that this organ could be a potential source of the bioactive chemicals. In y-maze assays, sexually mature, but not subadult, cuttlefish, were attracted to odors of cuttlefish eggs. These data suggest that Sepia eggs could be a source of reproductive pheromones.     

Single-chain Fv fragments of anti-neuraminidase antibody NC10 containing five- and ten-residue linkers form dimers and with zero- residue linker a trimer

Single-chain variable fragments (scFvs) of anti-neuraminidase antibody NC10 were constructed by joining the VH and VL domains with 10-residue (Gly4Ser)2 and five-residue (Gly4Ser) linkers; a zero-residue linker scFv was constructed by joining the C-terminal residue of the VH domain to the N-terminus of the VL domain. The scFv with the 10- and five- residue linkers exclusively formed dimeric antibody fragments (M(r) 52000). These were shown to be bivalent and were able to cross-link two neuraminidase tetramers to form a 'sandwich' type complex; each antigen combining site could also bind an anti-idiotype Fab'. The zero-residue linker scFv (M(r) 70000) was shown to form a trimer with three active antigen combining sites, each binding an anti-idiotype Fab' to yield a complex of M(r) 212000. The orientation of the combining sites in the zero-residue linker scFv, however, was such that it could not cross- link tetramers of neuraminidase. BIAcore biosensor experiments showed that the affinity of each individual antigen combining site in both the 10- and five-residue linker scFv dimers and zero-residue linker scFv trimer was essentially the same when the scFvs were immobilized onto the sensor surface. However, when the scFvs were used as the analyte, the dimeric and trimeric scFvs showed an apparent increase in binding affinity due to the avidity of binding the multivalent scFvs.      

Degradation and bioavailability of dried alginate hydrocolloid capsules in simulated soil system

Hydrocolloid capsules are common chemical carriers used in many types of applications in foods, biotechnology, and agriculture. Alginate microbeads and macrobeads are some of the more prevalent types of hydrocolloid capsules. Most studies to date have focused on alginate carrier applications but only a few have looked at their bioavailability after use. In this study, alginate carriers were subjected to simulated field conditions and their biodegradation in the soil was evaluated by respiration measurements, visualization, and volatile solids reduction. Using respiration rate, the degradation rate was calculated at 32 ± 3.1% (w/w) after 2 months. The visually estimated volume and volatile solids reduction gave degradation rates of 40 ± 8.6% (v/v) and 22.5 ± 2.5% (w/w), respectively. Moreover, water-loss calculations suggested that the carriers can serve as a stand-alone soil amendment for water retention. These findings emphasize the importance of studying hydrocolloid bioavailability in the soil and alginate carrier suitability for future applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48142.     

Structure,nanomechanics, and dynamics of dispersed surfactant‐free clay nanocomposite films

The current work presents a new approach to achieve high quality dispersion of surfactant‐free nanoclay tactoid particles in sub‐micron thin films despite the absence of organic modifier. Natural Montmorillonite particles, Cloisite, were dispersed in thin films of polycaprolactone (PCL) through a flow coating technique assisted by ultra‐sonication. Wide‐angle X‐ray scattering (WAXS), grazing‐incidence wide‐angle X‐ray scattering (GI‐WAXS), and transmission electron microscopy (TEM) were used to confirm the level of natural clay dispersion down to the level of tactoids (sub‐micron scale stacks of clay sheets). These characterization techniques were carried out in conjunction with an analysis of nanomechanical properties via strain‐induced buckling instability for modulus measurements (SIEBIMM), a high‐throughput technique to characterize thin film mechanical properties. The buckling patterns indicate that the natural clay tactoids separate buckling‐enhancing (high‐modulus) crystalline regions and interconnect buckling‐suppressing amorphous (low‐modulus) regions. Due to the tactoid length scale, the glass transition behavior of the composites as characterized by broadband dielectric relaxation spectroscopy was unmodified by the clay. Likewise, the glass transition temperature, T_g, and fragility (slope of relaxation time behavior approaching T_g), remain unaffected, indicating that these dispersed tactoids do not induce pronounced confinement effects on dynamics. POLYM. ENG. SCI., 58:1285–1295, 2018. © 2018 Society of Plastics Engineers     

Concentrated slurry formation via drawdown and incorporation of wettable solids in a mechanically agitated vessel

This article describes the effect of vessel configurations on the drawdown and incorporation of floating solids to prepare concentrated alumina slurries in stirred tanks. The impeller speed and power draw required to incorporate all dry powder within four seconds, N_JI and P_JI, are used to evaluate incorporation performance. The effect of impeller type is assessed, with pitched blade impellers proving to be the most effective across the full range of solid contents considered. At higher solids content the energy demand is shown to increase dramatically, with a 100‐fold increase in energy required to add 1% w/w more solid at 50% by weight compared to 1% by weight. Analysis of impeller power numbers show this coincides with a transition from constant power number to a region where power number increases linearly with decreasing Reynolds number. Contrary to studies at low solids content, the presence of baffles is shown to inhibit drawdown. © 2018 The Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers AIChE J, 64: 1885–1895, 2018     

Residual film thickness following immiscible fluid displacement in noncircular microchannels at large capillary number

An experimental study of the displacement of one immiscible fluid by another was performed in microchannels with circular, square and near‐semicircular cross‐sections, with hydraulic diameters from 100 to 200 μm. Experiments were performed over a range of capillary number, Ca, from 0.02 < Ca < 80, with viscosity ratios between the two fluids ranging from 20 to 100. The liquid film left on the channel wall following the advance of the displacing fluid was obtained from visual measurements and a method for the estimation of mean film thickness was shown to be in good agreement with existing correlations. The addition of a surfactant (Sodium Dodecyl Sulfate, SDS) dissolved in the displacing fluid led to a reduction in the thickness of the residual film. © 2018 The Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers AIChE J, 64: 3456–3466, 2018