Gay Side Story Original Poster

Poster for original production of GAY SIDE STORY as presented in conjunction with Symposium X at the University of Southern Maine, 1983.https://digitalcommons.usm.maine.edu/gay_side_story/1000/thumbnail.jp

The effect of addition of ceria on platinum supported on carbon materials in the hydrogenation of ethylene

This study reports the synthesis of carbon materials (carbon nanotubes (CNTs), coiled carbon nanofibers (CCNFs) and carbon spheres (CSs)) using the chemical vapour deposition (CVD) method. The as-synthesized carbon materials were functionalized using nitric acid in order to introduce functional groups and improve the hydrophilic behavior of the carbon materials. Both the as-synthesized and functionalized carbon materials were characterized by TEM, TGA, Raman and FTIR spectroscopy. The presence of functional groups was confirmed by alkalimetry titration and IR spectroscopy data. Ceria (synthesized using the sol-gel method), activated carbon (AC) and titania (P25) were other catalysts supports used and their morphologies were determined by TEM. Platinum was deposited on the various supports to give Pt loadings of 0.5, 1 and 5 % using the polyol method. It was found that small Pt particle sizes were obtained with average particle sizes of 1.8, 2.3, 2.6, 2.9, 2.7 and 1.6 nm for Pt/CCNF, Pt/CNT, Pt/CS, Pt/AC, Pt/CeO2 and Pt/TiO2 respectively at 0.5 % Pt loading. Pt was also deposited on the CeO2/CM supports (5 % and 10 % CeO2 loadings) to make Pt-CeO2/CM catalysts. The Pt supported catalysts were characterized by TEM, EDS, XRD, TPR, BET and TGA. The platinum supported catalysts were tested for the hydrogenation of ethylene. The effect of functionalization of the carbon materials was determined. Pt/functionalized carbon materials had better activity than Pt/as-synthesized carbon materials. On the effects of supports; Pt/TiO2 showed the best activity compared to Pt/CCNF, Pt/CNT, Pt/CS, Pt/AC, Pt/CeO2 and this was attributed to the small Pt sizes formed on TiO2 (Pt mean size was 1.6 nm). An interesting feature in this study was the higher activity of the Pt-CeO2/CM as compared to Pt/CM. This was due to the effect of ceria in preserving the surface area of Pt by suppressing sintering. The effect of increasing the ratio of hydrogen to ethylene was investigated and the findings indicated that all the ethylene was converted to ethane. This was attributed to the fact that at a high hydrogen concentration, the rate of formation of the carbon deposit is slow and the rate of hydrogenation is high. No carbon deposits are thus expected on the Pt catalyst particles. It was found that an increase in the Pt loading resulted in an increase in the rate of reaction

Electrode surface modification using metallophthalocyanines and metal nanoparticles : electrocatalytic activity

Metallophthalocyanines and metal nanoparticles were successfully synthesized and applied for the electrooxidation of amitrole, nitrite and hydrazine individually or when employed together. The synthesized materials were characterized using the following techniques: predominantly scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), electrochemistry and scanning electrochemical microscopy (SECM). Different electrode modification methods were used to modify the glassy carbon substrates. The methods include adsorption, electrodeposition, electropolymerization and click chemistry. Modifying the glassy carbon substrate with MPc (electropolymerization) followed by metal nanoparticles (electrodeposition) or vice versa, made a hybrid modified surface that had efficient electron transfer. This was confirmed by electrochemical impedance studies with voltammetry measurements having lower detection potentials for the analytes. This work also describes for the first time the micropatterning of the glassy carbon substrate using the SECM tip. The substrate was electrografted with 4-azidobenzenediazonium salt and then the click reaction was performed using ethynylferrocene facilitated by Cu⁺ produced at the SECM tip. The SECM imaging was then used to show the clicked spot

The influence of gold nanoparticles on the electroactivity of nickel tetrasulfonated phthalocyanine

We report on the electrodeposition of gold nanoparticles (AuNPs) on a glassy carbon electrode (GCE) followed by deposition of nickel tetrasulfonated phthalocyanine (NiTSPc) film by electropolymerization (poly-NiTSPc-GCE) to form Poly-NiTSPc/AuNPs-GCE. The presence of the gold nanoparticles caused a lowering of the anodic and cathodic peak separation (ΔEp) of ferricyanide from 126 mV on poly-NiTSPc to 110 mV on poly-NiTSPc/AuNPs. The electrooxidation of nitrite improved on modified electrodes compared to GCE, with the latter giving Ep = 0.78 V and the modified electrodes gave Ep = 0.62 V or 0.61 V. Poly-NiTSPc/AuNPs-GCE had higher currents compared to poly-NiTSPc-GCE. This indicates the enhancement effect caused by the AuNPs. Electrochemical impedance spectroscopy and chronoamperometric studies also showed that poly-NiTSPc/AuNPs-GCE was a better electrocatalyst than poly-NiTSPc-GCE or AuNPs-GCE

Characterization of electrodes modified by one pot or step by step electro-click reaction and axial ligation of iron tetracarboxyphthalocyanine

The modification of the glassy carbon electrode (GCE) was carried out using two methods. The first method is simultaneous electropolymerization and electro-click followed by immersion into a solution of dimethyl formamide (DMF) containing FeTCPc. The second method is step by step whereby electropolymerization is carried out first followed by electro-click and then immersion into a DMF solution containing FeTCPc. From the electrochemical characterization, it was observed that the second route (step by step method) was the best as indicated by the ferricyanide studies (cyclic voltammetry and scanning electrochemical microscopy). In the electrooxidation of hydrazine, we obtained a potential of 0.26 V. Of interest were the detection limit of 6.4 μM and the catalytic rate constant of 2.1 × 109 cm3 mol−1 s−1. This shows that the sensor can be used for the electrooxidation of hydrazine

Electrocatalytic activity of bimetallic Au–Pd nanoparticles in the presence of cobalt tetraaminophthalocyanine

Au and Pd nanoparticles were individually or together electrodeposited on top of polymerized cobalt tetraaminophthalocyanine (poly-CoTAPc). When Pd and Au nanoparticles are co-deposited together, the electrode is denoted as Au–Pd (co-deposited)/poly-CoTAPc-GCE. X-ray photoelectron spectroscopy (XPS) was used to show the successful deposition of AuNPs, PdNPs and Au–Pd (co-deposited). The scanning electrochemical microscopy showed that Au–Pd (co-deposited)/poly-CoTAPc-GCE (with current range of 9.5–13.5 lA) was more conducting than Au–Pd (co-deposited)-GCE (with current range of 8–12 lA). Electrochemical impedance spectroscopy (EIS) showed that there was less resistance to charge transfer for Au–Pd (co-deposited)/poly-CoTAPc-GCE compared to the rest of the electrodes. Au–Pd (co-deposited)/poly-CoTAPc-GCE showed the best activity for the electrooxidation of hydrazine in terms of limit of detection (0.5 lM), hence shows promise as an electrocatalyst for electrooxidation of hydrazine

Electrocatalytic activity of bimetallic Au–Pd nanoparticles in the presence of cobalt tetraaminophthalocyanine

Au and Pd nanoparticles were individually or together electrodeposited on top of polymerized cobalt tetraaminophthalocyanine (poly-CoTAPc). When Pd and Au nanoparticles are co-deposited together, the electrode is denoted as Au–Pd (co-deposited)/poly-CoTAPc-GCE. X-ray photoelectron spectroscopy (XPS) was used to show the successful deposition of AuNPs, PdNPs and Au–Pd (co-deposited). The scanning electrochemical microscopy showed that Au–Pd (co-deposited)/poly-CoTAPc-GCE (with current range of 9.5–13.5 lA) was more conducting than Au–Pd (co-deposited)-GCE (with current range of 8–12 lA). Electrochemical impedance spectroscopy (EIS) showed that there was less resistance to charge transfer for Au–Pd (co-deposited)/poly-CoTAPc-GCE compared to the rest of the electrodes. Au–Pd (co-deposited)/poly-CoTAPc-GCE showed the best activity for the electrooxidation of hydrazine in terms of limit of detection (0.5 lM), hence shows promise as an electrocatalyst for electrooxidation of hydrazine

Characterization and electrocatalytic behaviour of glassy carbon electrode modified with nickel nanoparticles towards amitrole detection

We report on the synthesis of Ni nanoparticles (NiNPs) and their application in electrocatalysis in comparison with nickel phthalocyanine (NiPc). UV–vis spectroscopy, powder X-ray diffraction, transmission electron microscopy and electron paramagnetic resonance were used in the characterization of NiNPs. Cyclic voltammetry and electrochemical impedance spectroscopy were used in electrocatalytic studies of amitrole on the glassy carbon electrode modified with NiNPs. The apparent and catalytic rate constants for amitrole on the NiNP-GCE were found to be 2.58 × 10−5 cm s−1 and 1.11 × 103 M−1 s−1, respectively

Learning Abstract Words and Concepts: Insights from Developmental Language Disorder

Some explanations of abstract word learning suggest that these words are learnt primarily from linguistic input, using statistical co-occurrences of words in language whereas concrete words can also rely on non-linguistic, experiential information. According to this hypothesis, we expect that, if the learner is not able to fully exploit the information in the linguistic input, abstract words should be affected more than concrete ones. Embodied approaches, instead, argue that both abstract and concrete words can rely on experiential information and, therefore, there might not be any linguistic primacy. Here, we test the role of linguistic input in the development of abstract knowledge with children with Developmental Language Disorder (DLD) and Typically Developing (TD) children aged 8-13. We show that DLD children, who by definition have impoverished language, do not show a disproportionate impairment for abstract words in lexical decision and definition tasks. These results indicate that linguistic information does not have a primary role in the learning of abstract concepts and words, rather, it would play a significant role in semantic development across all domains of knowledge

Thematic role assignment in the L1 acquisition of Tagalog: use of word order and morphosyntactic markers

It is a common finding across languages that young children have problems in understanding patient-initial sentences. We used Tagalog, a verb-initial language with a reliable voice-marking system and highly frequent patient voice constructions, to test the predictions of several accounts that have been proposed to explain this difficulty: the frequency account, the Competition Model, and the incremental processing account. Study 1 presents an analysis of Tagalog child-directed speech which showed that the dominant argument order is agent-before-patient, and that morphosyntactic markers are highly valid cues to thematic role assignment. In Study 2, we used a combined self-paced listening and picture verification task to test how Tagalog-speaking adults and 5- and 7- year-old children process reversible transitive sentences. Results showed that adults performed well in all conditions, while children’s accuracy and listening times for the first noun phrase indicated more difficulty in interpreting patient-initial sentences in the agent voice compared to the patient voice. The patient voice advantage is partly explained by both the frequency account and incremental processing account