Covert rehearsal of tones.

Z. F. Peynircio?lu and M. L. Palmer (see record 1993-04390-001) found that memory for simple pairs or triples of tones did not benefit from covert rehearsal, although it did benefit from repetition. The present study systematically explored people's ability to rehearse different dimensions and varied the complexity of the musical stimuli. The first 6 experiments showed that even though repetition of tone pairs with pitch or interval as the relevant information led to better long-term recognition, covert rehearsal of the same stimuli did not. The next 2 experiments showed that covert rehearsal of pitch and interval information did benefit immediate recognition, however. The last 2 experiments showed that with more complex musical stimuli covert rehearsal can be effective and can lead to better long-term recognition. The results are discussed within the context of the transfer-appropriate processing framework. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Electrocatalytic oxygen reduction and hydrogen evolution reactions on phthalocyanine modified electrodes: Electrochemical, in situ spectroelectrochemical, and in situ electrocolorimetric monitoring

This study describes electrochemical, in situ spectroelectrochemical, and in situ electrocolorimetric monitoring of the electrocatalytic reduction of molecular oxygen and hydronium ion on the phthalocyanine-modified electrodes. For this purpose, electrochemical and in situ spectroelectrochemical characterizations of the metallophthalocyanines (MPc) bearing tetrakis-[4-((4′-trifluoromethyl)phenoxy)phenoxy] groups were performed. While CoPc gives both metal-based and ring-based redox processes, H₂Pc, ZnPc and CuPc show only ring-based electron transfer processes. In situ electrocolorimetric method was applied to investigate the color of the electrogenerated anionic and cationic forms of the complexes. The presence of O₂ in the electrolyte system influences both oxygen reduction reaction and the electrochemical and spectral behaviors of the complexes, which indicate electrocatalytic activity of the complexes for the oxygen reduction reaction. Perchloric acid titrations monitored by voltammetry represent possible electrocatalytic activities of the complexes for hydrogen evolution reaction. CoPc and CuPc coated on a glassy carbon electrode decrease the overpotential of the working electrode for H⁺ reduction. The nature of the metal center changes the electrocatalytic activities for hydrogen evolution reaction in aqueous solution. Although CuPc has an inactive metal center, its electrocatalytic activity is recorded more than CoPc for H⁺ reduction in aqueous solution.     

Efficiency of Structural Materials in Sustainable Design

The main aim of this paper is to investigate energy consumptions, CO2 emissions and costs during the production and life cycle of structural materials. The virgin and recycled metals as well as waste minerals such as fly ash, slag in concrete save energy consumption, CO2 emissions and costs. The importance and effectiveness of recycled materials will be statistically evaluated via energy consumption, carbon footprint, ultimate strength and their ratios. Embodied energy to ultimate strength or embodied carbon to ultimate strength ratios may emphasize the effectiveness of a sustainable material. The analyses in this study indicate the utilization of the recycled steel and C50 concrete with 50% fly ash or slag is the most efficient way of using sustainable materials.     

Preparation and characterization of poly(acrylic acid)/pillared clay superabsorbent composite

Pillared clay-based superabsorbents (PILC-SA) were synthesized by using Al pillared-montmorillonite K10 and KSF via graft copolymerization reaction of acrylic acid (AA). Swelling behavior of pillared clay-based superabsorbent films in distilled water and at different pH values were investigated at room temperature. It was also obtained that Al-KSF and Al-K10 based superabsorbents were pH dependent and showed a reversible swelling behavior. Water absorbency of Al-KSF based superabsorbent was higher than that of Al-K10 based one. SEM, FTIR, and XRD analysis were conducted for further characterization of the PILC-SA. FTIR analyses lead to ester formation between PILC and SA. XRD revealed the basal spacing of the pillared clays before and after in situ incorporation indicating that the morphology of the superabsorbent was exfoliated and the layers of clay dispersed on the composite.     

Robust adaptive H∞ control design for heart rate regulation during rhythmic exercises of unknown type

The aim of the study is to regulate the human heart rate (HR) response to a predefined reference profile during aerobic activities of unknown type. A novel feature of the designed control system is obtained to generate the desired rhythmic movements, which is required to achieve the target HR profile during aerobic activities of unknown type. These rhythmic movements or frequency of locomotion is known as the exercise rate (ER) and is quantified as a fundamental measure of exercise intensity. The relationship between ER and HR is modeled by using a linear time‐varying system. The parameters of the model are estimated using a Kalman filter. Based on this model, a robust adaptive H_∞ controller is designed. The H_∞ controller generates target ER (ER_T) corresponding to target HR (HR_T). This ER_T is communicated to the exercising subject by using a human actuating system (HAS). The role of HAS is to achieve ER_T. To validate the performance of the system, it is tested on six healthy subjects during rowing and cycling exercises. The results demonstrate that the designed control system can regulate HR at a given profile with an average root mean square error of 3.1857 bpm and 2.9396 bpm for rowing and cycling, respectively. The developed system can be used for designing an optimal exercising protocol for individuals.