Magnetic refrigeration at room temperature is of great interest due to a long-term goal of making refrigeration more energy-efficient, less noisy and free of any environmentally hostile materials. A refrigerator utilizing an active magnetic regenerator (AMR) is based on the magnetocaloric effect, which manifests itself as a temperature change in magnetic materials when subjected to a varying ma...

A performance analysis on a vapour compression refrigeration system with various refrigerants mixture of R152a, RE170, R600a, and R290 were done for various mixture ratios and their results were compared with R134a as possible alternative replacement. The results showed that all of the alternative refrigerants investigated in the analysis except R431A, [R 152a (29%), R290 (71%)] have a slightly...

The present work deals with thermodynamic analysis of cascade refrigeration system using ozone friendly refrigerants pair R507A and R23. R507A is azeotropic mixture composed of HFC refrigerants R125/R143a (50%/50% wt.). R23 is a single component HFC refrigerant used as replacement to CFC refrigerant R13 in low temperature applications. These refrigerants have zero ozone depletion potential and ...

Practice can dramatically reduce dual-task interference, but typically does not eliminate interference entirely. Residual interference after practice is especially large with certain non-preferred modality pairings (e.g., auditory-manual and visual-vocal). Does this residual interference imply the existence of a persistent central-processing bottleneck? To address this question, we transferred ...

In this research, the controversial issue of whether the central bottleneck can be bypassed through task automatization was investigated. To examine this issue, participants received six single-task practice sessions with an auditory-vocal task (low vs. high pitch). We then assessed dual-task performance using the analytically tractable psychological refractory period (PRP) paradigm, in which t...

The authors examined the role of online order control in the psychological refractory period (PRP) paradigm. In the first 2 experiments, participants switched between color-letter and letter-color orders so that subtask order was isolated as the only element being switched. The results indicated that order switching impaired the 2 PRP responses and modulated the PRP effect. Importantly, these e...

The divergent predictions of 2 models of dual-task performance are investigated. The central bottleneck and central capacity sharing models argue that a central stage of information processing is capacity limited, whereas stages before and after are capacity free. The models disagree about the nature of this central capacity limitation. The central bottleneck model claims that central processin...

Some studies suggest that dual-task processing impairs sequence learning; others suggest it does not. The reason for this discrepancy remains obscure. It may have to do with the dual-task procedure often used. Many dual-task sequence learning studies pair the serial reaction time (SRT) task with a tone-counting secondary task. The tone-counting task, however, is not ideal for studying the cogni...