The present work concerns on the investigation of the role of polyethylene glycols (PEGs) as masking agent for amelioration of extraction-separation of La(III), Eu(III) and Er(III) ions by the acidic extractant bis(2-ethylhexyl)phosphoric acid (DEHPA). The studied solvent extraction system is based on the combination of chelating effect of DEHPA in the organic phase on the one hand, and the bin...

Many sensory discriminations, including the discrimination of speed, obey Weber's law and thus become more difficult as the stimuli get larger. Using one-jump apparent motion stimuli, we find that the opposite can occur: displacement discrimination improves with larger jumps. This pedestal effect occurs for small jumps near and below the detection threshold. Finding a pedestal effect in motion ...

A simple, sensitive and rapid method for determination of trace amounts of nitrite ion in real samples is reported. The reaction is initiated by adding known volumes of a nitrite ion solution of identified concentration to acidic solutions of thionine which causes decolorizaiton of reagent with time. The absorbance changes is then monitored spectrophotometrically at l...

Many natural sounds, including speech and animal vocalizations, involve rapid sequences that vary in spectrum and amplitude. Each sound within a sequence has the potential to affect the audibility of subsequent sounds in a process known as forward masking. Little is known about the neural mechanisms underlying forward masking, particularly in more realistic situations in which multiple sounds f...