Use of copper and gold electrodes as sensitive elements for fabrication of an electronic tongue: Discrimination of wines and whiskies

A low-cost method is proposed to classify wine and whisky samples using a disposable voltammetric electronic tongue that was fabricated using gold and copper substrates and a pattern recognition technique (Principal Component Analysis). The proposed device was successfully used to discriminate between expensive and cheap whisky samples and to detect adulteration processes using only a copper electrode. For wines, the electronic tongue was composed of copper and gold working electrodes and was able to classify three different brands of wine and to make distinctions regarding the wine type, i.e., dry red, soft red, dry white and soft white brands. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.

Surface-Enhanced Resonance Raman Scattering of Polyaniline on Silver and Gold Colloids

The interaction of emeraldine base (PANI-EB) with silver and gold colloids was probed by using Surface-Enhanced Resonance Raman Scattering (SERRS) at 3 different exciting radiations. Due to the great sensitivity of SERRS technique the detection limit of PANI-EB concentration was ca. 2 x 10(-7) mol L(-1) in Ag and Au colloidal suspensions. The UV-vis-NIR spectra of metal colloids in function of PANI-EB concentrations showed that gold colloids present a higher degree of aggregation than silver colloids. SERRS of PANI-EB on metal colloids allowed the study of the polymeric species formed primarily on the metallic surface. The polymer formed after the adsorption of PANI-EB on metallic nanoparticles is strongly dependent on the nature of the metal colloids. The oxidation of PANI-EB to pernigraniline occurred for silver colloids, while a doping process of PANI-EB on Au nanoparticles was evidenced through the observation of the characteristic SERRS spectrum of emeraldine salt at 1064nm.

Deposition of selenium thin layers on gold surfaces from sulphuric acid media: Studies using electrochemical quartz crystal microbalance, cyclic voltammetry and AFM

In this paper we report here new considerations about the relationship between the mass and charge variations (m/z relationship) in underpotential deposition (UPD), bulk deposition and also in the H(2)Se formation reaction. Nanogravimetric experiments were able to show the adsorption of H(2)SeO(3) on the AuO surface prior to the voltammetric sweep and that, after the AuO reduction, 0.40 monolayer of H(2)SeO(3) remains adsorbed on the newly reduced Au surface, which was enough to gives rise to the UPD layer. The UPD results indicate that the maximum coverage with Se(ads) on polycrystalline gold surface corresponds to approximately 0.40 monolayer, in good agreement with charge density results. The cyclic voltammetry experiments demonstrated that the amount of bulk Se obtained during the potential scan to approximately 2 Se monolayers, which was further confirmed by electrochemical quartz crystal microbalance (EQCM) measurements that pointed out a mass variation corresponding of 3 monolayers of Se. In addition, the Se thin films were obtained by chronoamperometric experiments, where the Au electrode was polarized at +0.10V during different times in 1.0 M H(2)SO(4) + 1.0 mM SeO(2). The topologic aspects of the electrodeposits were observed in Atomic Force Microscope (AFM) measurements. Finally, in highly negative potential polarizations, the H(2)Se formation was analyzed by voltammetric and nanogravimetric measurements. These finding brings a new light on the selenium electrodeposition and point up to a proposed electrochemical model for molecule controlled surface engineering. (c) 2009 Elsevier Ltd. All rights reserved.

Study of a gold electrode modified by trans-[Ru(NH(3))(4)(Ist)SO(4)](+) to produce an electrochemical sensor for nitric oxide

The modification of a gold electrode surface by electropolymerization of trans-[Ru(NH(3))(4)(Ist)SO(4)](+) to produce an electrochemical sensor for nitric oxide was investigated. The influence of dopamine, serotonin and nitrite as interferents for NO detection was also examined using square-wave voltammetry (SWV). The characterization of the modified electrode was carried out by cyclic voltammetry, electrochemical quartz crystal microbalance (EQCM) and SERS techniques. The gold electrode was successfully modified by the trans-[Ru(NH(3))(4)(Ist)SO(4)](+) complex ion using cyclic voltammetry. The experiments show that a monolayer of the film is achieved after ten voltammetric cycles, that NO in solution can coordinate to the metal present in the layer, that dopamine, serotonin and nitrite are interferents for the detection of NO, and that the response for the nitrite is much less significant than the responses for dopamine and serotonin. The proposed modified electrode has the potential to be applied as a sensor for NO. (C) 2011 Elsevier Ltd. All rights reserved.

The origin of the molecular interaction between amino acids and gold nanoparticles: A theoretical and experimental investigation

This study describes the synthesis of novel biological hybrid materials, where 3D structures were obtained using gold nanoparticles (AuNps) and methionine (Met) in a one-step procedure in aqueous media. The type of nanostructure can be controlled by tuning the intermolecular interactions between Met and AuNp, which strongly depends on the pH used for the synthesis. Computational simulation using the density-functional theory (DFT) showed that the AuNp - Met 3D structures are formed upon reorientation of Met molecules so that the backbone amine groups interact via H-bonds. These findings were experimentally confirmed using FTIR and UV-vis spectroscopy. Crown Copyright (C) 2008 Published by Elsevier B. V. All rights reserved.

Nat Gold, Sheet Metal Graduate from the New York Trade School

Nat Gold graduated from the Sheet Metal program at the New York Trade School in 1942. He is represented here in the sheet metal shop he owns. Notice the blueprints for the White Plains Senior High School hanging on the wall behind him. Original caption reads, "Shop Owner, Brook Sheet Metal Inc. Nat Gold - Sheet Metal 1942, represents one of many Sheet Metal graduates who became owners of their own business." Black and white photograph.

Samurai in the surf : the arrival of the Japanese on the Gold Coast in the 1980s

Samurai in the Surf explores the history of Japanese investment in the 1980s, following a money-trail that leads back to a ballooning Japanese economy and a colorful array of investment sources. The book also explores the local community's views of this unprecedented stream of foreign investment and provides a convincing illustration of the links between 1980s Queensland and Pauline Hanson's One Nation movement of the 1990s.

Chemical and physical speciation of arsenic in a small pond receiving gold mine waste effluent

The chemical and physical speciation of arsenic in a small pond that receives wastewater from a gold mine operation in western Victoria, Australia was studied using differential pulse polarography. By using different sample pretreatments, distinction between the physical states (dissolved or particulate As), between the oxidation states (As(III) or As(V)), and between the degrees of lability (labile or strongly bound) was achieved. The results are interpreted in terms of the physicochemical properties with reference to the use of the pond as a settlement dam for gold mining effluent. The speciation of arsenic was found to vary markedly with the physicochemical properties of the water. A model for the behavior of arsenic in the pond is proposed.

How well does club head speed correlate with gold handicaps?

The velocity at which a golf club impacts with a golf ball is known as club head speed. Although club head speed has been used to measure performance changes in a number of golf studies, it has not been validated as a golf performance measure. As handicap is the usual measure of performance, the purpose of this study was to investigate the relationship between club head speed and handicap, and to determine whether club head speed at impact is a valid measure of golfing performance. Forty-five male golfers aged 18–80 years, all with registered golfing handicaps (2–27), participated in this study. Each golfer performed 10 golf swings captured by a high-speed camera. Golfers' club head speeds were determined using Video Expert 2, a biomechanical computer program. Golfers with a lower handicap (ie, a better skill level) had faster club head speeds than higher handicap golfers. Linear regression analysis found club head speed to be highly correlated with handicap (r= 0.950). This relationship was described by the equation: In (club head speed)= 4.065 − 0.0214 x handicap. In conclusion, this study has shown that club head speed is a valid indicator of performance in golfers and may therefore be a useful performance measure in future laboratory-based studies.

The online learning alchemist : preventing gold turning into lead

This paper addresses the creation of materials and resources for use in online learning, focusing on the new and emerging roles for teachers and learners in conjunction with developments in our understanding of the human-computer interface. As more educational providers adopt network-based technologies as delivery portals, the demand for skills in the creation of effective online resources is becoming critical. If we are to provide the learner with online resources that will enhance knowledge construction and the teacher with clear measures that these activities are effective, then we as resource developers must resurrect the role of what might be termed the online alchemist. Our first task is to ensure that new digital resources are not simply transferred from their original format but repurposed to ensure learner(s) accessing those resources are able to interact with both the content and their collaborative partners with new levels of flexibility and manipulation. We must transcend the too frequent use of technology as a means to replicate existing resources and conceptualise environments that engender new paradigms for teaching and learning. Our challenge remains to ensure the gold we have in effective teaching strategies and learning resources is not tarnished through ineffective applications within the online learning context. One strategy to achieve this is through proactive evaluation, a framework that integrates a set of factors and influences to better inform the development of online learning resources.

Mining more gold from web page hyperlinks

The development of the Internet has boosted prosperity of the World Wide Web, which is now a huge information source. Because of characteristics of the web, in most cases, traditional databasebased technologies are no longer suitable for web information retrieval and management. To effectively manage web information, it is necessary to reveal intrinsic relationships/structures among web information objects by eliminating noise factors. This paper proposes a mechanism that could be widely used in information processing, including web information processing and noise factor elimination for getting more intrinsic relationships. As an application case of this mechanism, one relevant web page finding algorithm is proposed to uncover intrinsic relationship among web pages from their hyperlink patterns, and find more semantic relevant web pages. The experimental evaluation shows the feasibility and effectiveness of the algorithm and demonstrates the potential of the proposed mechanism in web applications.

Evelyn Levine Gold Scrapbook

Evelyn Mae Levine was born April 11, 1907 and died on February 6, 1957. She was one of the children born to William and Sarah Levine. The scrapbook includes photographs, family memories, negative copies of grade sheets from Coburn Classical Instituteand Emerson College.