Boron nitride as a processing aid for the extrusion of polyolefins and fluoropolymers

The influence of a new processing additive (fine particles of boron nitride) on the processability of polyolefins and fluoropolymers in extrusion is studied. The equipment used includes an Instron capillary rheometer with two types of dies, namely capillary dies and special annular dies (Nokia Maillefer wire coating crosshead) attached to the rheometer, and an extruder. Two metallocene polyethylenes and several Teflon® fluoropolymers were tested using these two pieces of equipment. The additive had a significant effect on the extrudate appearance of polyethylene and fluoropolymer particularly in the crosshead dies. It was found to eliminate surface melt fracture and to postpone the critical shear rate for the onset of gross melt fracture to significantly higher values depending on resin type, temperature, and additive concentration (typically 0.005% to 0.5%). To explain the possible mechanism for the effect of the additive on the processability of the resins, rheological measurements using both parallel‐plate and sliding‐plate rheometers were carried out. The rheology of the resins did not seem to change significantly with the addition of boron nitride except for the low‐shear‐rate (low‐frequency) range, where the behavior of the filled resin was found to be similar to that of a crosslinked polymer or a phase‐separated entangled blend. Practical wire coating and tubing extrusion studies for these resins were also carried out.     

Awareness of the response after feedback training for changes in heart rate and sudomotor laterality.

Examined the relation between (a) the ability to control visceral responding on a biofeedback (BFB) task and (b) the ability to report behaviors actually contributing to this performance in 4 experiments with 97 male Ss. Ss received BFB training for unidentified visceral responses and then gave written reports about what they had done to control BFB displays. Independent judges were given these reports and, on the basis of knowledge about activities known to contribute to visceral activity, were asked to determine the visceral responses for which Ss had been trained. The reports of Ss who succeeded at bidirectional control of heart rate (Exp I) or sudomotor laterality (Exp II) showed awareness of behaviors related to BFB as assessed by this procedure, whereas the reports of Ss who failed at bidirectional control did not. Subsequent experiments indicated that these results did not depend on a learning strategy that might have been specific to the initial studies. Findings question the view that people are unaware of what they have done to produce the response after training on BFB tasks. (81 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Family system variables and the health status of adolescents with insulin-dependent diabetes mellitus.

Investigated the associations between dimensions of family relations and the metabolic control of insulin-dependent diabetes mellitus (IDDM) in 94 adolescents (mean age 14.4 yrs) from intact families. Metabolic control was determined by adolescents' levels of hemoglobinHbA1c, and family relations were assessed with the Marital Adjustment Test and the Family Adaptation and Cohesion Evaluation Scales. Although zero-order correlations showed that good metabolic control was associated with high family cohesion, family flexibility, and high marital satisfaction, hierarchical regression analyses revealed that these associations were attenuated when demographic variables, especially the duration of IDDM, were controlled. Follow-up analyses showed that the associations between family relations and metabolic control were mediated by the duration of IDDM. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Powder-fed directed energy deposition of soda lime silica glass on glass substrates

Novel glass processing by powder-fed directed energy deposition was explored as a method of adding glass décor to glass surfaces and bottles. Consistent, semitransparent, single-line tracks of soda lime silica glass could be processed onto glass substrates of the same composition, without significant cracks forming in the substrate. A suitable processing window was found with laser power and scan speed showing independent effects on processing. Consideration of processing surface conditions and reduction of laser transmission through transparent substrates was necessary, and the use of an adhesive tape layer aided adhesion of glass feedstock to substrate surfaces. The work demonstrates the potential for a one-step method of glass bottle decoration for the packaging industry, with scope to create 3D designs of high geometric complexity and customizability on glass substrates, thereby adding value to glass packaging by brand differentiation without the high costs associated with molds and tooling.