Bartering: A Critical Review and Theoretical Conceptualization

The purpose of this theoretical ethics poster presentation is to review the bartering literature, develop a framework for understanding the construct, connect the practice of bartering to social justice and to outline recommendations for practitioners. Dimensions of bartering are discussed, and functional versus symbolic bartering is defined. Functional bartering is defined as a trade in lieu of money payment that fulfills a basic need of the therapist, while symbolic bartering is the trade of a good or service that does not meet the full value of the session but carries meaning for the client. Future research directions are proposed

Effects of low Ag additions on the hydrogen permeability of Pd–Cu–Ag hydrogen separation membranes

AbstractPd–Cu alloys are of potential interest for use as hydrogen purification membranes, but have relatively low permeability compared to the commercially used alloys such as Pd–Ag. In this work, the effects of partial Ag substitution on the hydrogen diffusivity, solubility and the permeability of Pd–Cu membranes with a bcc structure have been investigated. With the addition of 2.3 and 3.9at% Ag to Pd–Cu, lattice expansions of 0.11% and 0.35% were observed. Structural analyses by in-situ XRD showed that the bcc structure of the 2.3at% Ag alloy is retained upon heating to 600°C, whereas an fcc phase forms in the 3.9at% Ag alloy resulting in a mixed (bcc+fcc) structure. Whilst the diffusion coefficients between 350 and 400°C for both Pd–Cu–Ag ternary samples were shown to be lower than their binary alloys (which had similar structures), higher solubility values were obtained. The lower diffusion coefficients of the ternary alloys are related to an increase in the diffusion activation barrier in the presence of Ag, and the higher solubility values may be attributed to the lattice expansion and high Ag–H chemical interaction. Hydrogen permeation measurements showed that an enhancement in the hydrogen solubility of the bcc phase Pd45.8Cu51.9Ag2.3, does not have a substantial effect on the permeability of the membrane. In contrast, for the Pd45.1Cu51Ag3.9 sample with a mixed (bcc+fcc) phase, higher hydrogen solubility can lead to a remarkable improvement in permeability. Hence, it is suggested that the hydrogen permeability in the bcc phase is mainly controlled by hydrogen diffusion, and the solubility enhancement can only significantly improve the hydrogen permeability when the fcc phase is present

Primum non nocere: Refocusing our attention on severe hypoglycemia prevention

Severe hypoglycemia, defined as low blood glucose requiring assistance for recovery, is arguably the most dangerous complication of type 1 diabetes as it can result in permanent cognitive impairment, seizure, coma, accidents, and death. Since the Diabetes Control and Complications Trial (DCCT) demonstrated that intensive intervention to normalize glucose prevents long-term complications but at the price of a threefold increase in the rate of severe hypoglycemia, hypoglycemia has been recognized as the major limitation to achieving tight glycemic control. Severe hypoglycemia remains prevalent among adults with type 1 diabetes, ranging from ∼1.4% per year in the DCCT/EDIC (Epidemiology of Diabetes Interventions and Complications) follow-up cohort to ∼8% in the T1D Exchange clinic registr

Effects of thin film Pd deposition on the hydrogen permeability of Pd60Cu40 wt% alloy membranes

AbstractPd60Cu40 wt% (Pd47.3Cu52.7 at%) membranes were surface modified by depositing Pd thin films of three different thicknesses (~100, 800 and 1400nm) on to one side of a range of as-received Pd60Cu40 wt% cold-rolled foils via magnetron sputtering. The hydrogen permeability of the membranes was then measured and compared to the uncoated material. The Pd60Cu40 wt% membrane coated with a 1400nm thick Pd thin film positioned on the feed side (445kPa of hydrogen pressure) during hydrogen permeability measurements and cycled between 50 and 450°C achieved the highest hydrogen permeability of 1.09×10−8molm−1s−1Pa−0.5 at 450°C in the third cycle. This is a 58% increase on the value measured for the as-received Pd60Cu40 wt% membrane under the same conditions.This improvement can be attributed to a Pd-rich Pd–Cu face centred cubic (FCC) phase forming through interdiffusion between the Pd thin film and bulk Pd–Cu membrane as a result of the test conditions used during hydrogen permeability measurements. This introduces a larger hydrogen concentration gradient across the membrane due to the relatively high hydrogen solubility of the Pd-rich Pd–Cu FCC phase resulting in the observed increase in permeability.The Pd60Cu40 wt% membranes coated with a ~1400nm and ~800nm thick Pd thin film retained an almost pure Pd surface throughout cycling between 50 and 450°C with a feed and permeate hydrogen pressure of 445 and 100kPa, respectively. For the deposition technique and test conditions used throughout this work, these surface modified Pd–Cu membranes appear to stabilise the Pd thin films upon cycling across the critical temperature of 295 °;C