International Journal of Electrochemistry

Corrosion Behavior of the Stressed Sensitized Austenitic Stainless Steels of High Nitrogen Content in Seawater

A. Almubarak, W. Abuhaimed, and A. Almazrouee — Sun, 12 May 2013 18:55:58 +0000

The purpose of this paper is to study the effect of high nitrogen content on corrosion behavior of austenitic stainless steels in seawater under severe conditions such as tensile stresses and existence of sensitization in the structure. A constant tensile stress has been applied to sensitized specimens types 304, 316L, 304LN, 304NH, and 316NH stainless steels. Microstructure investigation revealed various degrees of stress corrosion cracking. SCC was severe in type 304, moderate in types 316L and 304LN, and very slight in types 304NH and 316NH. The electrochemical polarization curves showed an obvious second current peak for the sensitized alloys which indicated the existence of second phase in the structure and the presence of intergranular stress corrosion cracking. EPR test provided a rapid and efficient nondestructive testing method for showing passivity, degree of sensitization and determining IGSCC for stainless steels in seawater. A significant conclusion was obtained that austenitic stainless steels of high nitrogen content corrode at a much slower rate increase pitting resistance and offer an excellent resistance to stress corrosion cracking in seawater.

Electrochemical Behavior of Ni(II)-Salen at the Mercury Electrode

Pércio Augusto Mardini Farias and Margarida Bethlem Rodrigues Bastos — Mon, 22 Apr 2013 10:20:27 +0000

The complex Ni(II)-salen has been studied using cyclic and square-wave cathodic stripping voltammetry at the static mercury drop electrode in an aqueous media of phosphate and Hepes buffers (at pH 7.0). The resulting voltammograms consist of a totally irreversible one-electron transfer attributable to the coupling of Ni(II) salen/Ni(I) salen via an EC mechanism. The mean value for the transfer coefficient α in both supporting electrolytes was calculated as 0.35 ± 0.05. The amount of reactant adsorbed after 60 s of accumulation at −700 mV was calculated to be 2.8 × 10−8 mol·cm−2. The detection limit for nickel determination was found to be 3.4 × 10−9 mol L−1.

Formic Acid Electrooxidation by a Platinum Nanotubule Array Electrode

Eric Broaddus, Ann Wedell, and Scott A. Gold — Tue, 16 Apr 2013 15:03:59 +0000

One-dimensional metallic nanostructures such as nanowires, rods, and tubes have drawn much attention for electrocatalytic applications due to potential advantages that include fewer diffusion impeding interfaces with polymeric binders, more facile pathways for electron transfer, and more effective exposure of active surface sites. 1D nanostructured electrodes have been fabricated using a variety of methods, typically showing improved current response which has been attributed to improved CO tolerance, enhanced surface activity, and/or improved transport characteristics. A template wetting approach was used to fabricate an array of platinum nanotubules which were examined electrochemically with regard to the electrooxidation of formic acid. Arrays of 100 and 200 nm nanotubules were compared to a traditional platinum black catalyst, all of which were found to have similar surface areas. Peak formic acid oxidation current was observed to be highest for the 100 nm nanotubule array, followed by the 200 nm array and the Pt black; however, CO tolerance of all electrodes was similar, as were the onset potentials of the oxidation and reduction peaks. The higher current response was attributed to enhanced mass transfer in the nanotubule electrodes, likely due to a combination of both the more open nanostructure as well as the lack of a polymeric binder in the catalyst layer.

Buoyancy Effect of Ionic Vacancy on the Change of the Partial Molar Volume in Ferricyanide-Ferrocyanide Redox Reaction under a Vertical Gravity Field

Yoshinobu Oshikiri, Makoto Miura, and Ryoichi Aogaki — Mon, 25 Mar 2013 11:49:58 +0000

With a gravity electrode (GE) in a vertical gravity field, the buoyancy effect of ionic vacancy on the change of the partial molar volume in the redox reaction between ferricyanide (FERRI) and ferrocyanide (FERRO) ions was examined. The buoyancy force of ionic vacancy takes a positive or negative value, depending on whether the rate-determining step is the production or extinction of the vacancy. Though the upward convection over an upward electrode in the FERRO ion oxidation suggests the contribution of the positive buoyancy force arising from the vacancy production, the partial molar volume of the vacancy was not measured. On the other hand, for the downward convection under a downward electrode in the FERRI ion reduction, it was not completely but partly measured by the contribution of the negative buoyancy force from the vacancy extinction. Since the lifetime of the vacancy is decreased by the collision between ionic vacancies during the convection, the former result was ascribed to the shortened lifetime due to the increasing collision efficiency in the enhanced upward convection over an upward electrode, whereas the latter was thought to arise from the elongated lifetime due to the decreasing collision efficiency by the stagnation under the downward electrode.

Conductivity at Low Humidity of Materials Derived from Ferroxane Particles

Alberto Lapina, Peter Holtappels, and Mogens Mogensen — Thu, 08 Nov 2012 08:26:10 +0000

Carboxylic-acid-stabilised γ-FeOOH particles (ferroxanes) are synthesized using a precipitation from aqueous solution, and a following reaction with acetic acid. The materials produced with these powders are investigated by XRD, SEM, nitrogen adsorption-desorption, and impedance spectroscopy. Conductivity of both sintered and unsintered materials decreases strongly with a decrease in water partial pressure in the atmosphere during the test. The highest conductivity (7·10−3 S cm−1) is measured in air ( = 0.037 atm) at room temperature on sintered material. The conductivity values are compared with other works in the literature and the dependence of conductivity on surface area and pore size is discussed. It is suggested that both unsintered and sintered materials act as proton conductors at room temperature under moderate humidity conditions.

Ecofriendly Synthesis of Anisotropic Gold Nanoparticles: A Potential Candidate of SERS Studies

Ujjwala Gaware, Vaishali Kamble, and Balaprasad Ankamwar — Tue, 06 Nov 2012 11:43:42 +0000

Ecofriendly synthesis of nanoparticles has been inspiring to nanotechnologists especially for biomedical applications. Moreover, anisotropic particle synthesis is an attractive option due to decreased symmetry of such particles often leads to new and unusual chemical and physical behaviour. This paper reports a single-step room-temperature synthesis of gold nanotriangles using a cheap bioresource of reducing and stabilizing agent Piper betle leaf extract. On treating aqueous chloroauric acid solution with Piper betle leaf extract, after 12 hr, complete reduction of the chloroaurate ions was observed leading to the formation of flat and single crystalline gold nanotriangles. These gold nanotriangles can be exploited in photonics, optical coating, optoelectronics, magnetism, catalysis, chemical sensing, and so forth, and are a potential candidate of SERS studies.

Graphene: A Rising Star on the Horizon of Materials Science

Ujjal Kumar Sur — Thu, 20 Sep 2012 14:46:02 +0000

Graphene, a one-atom thick planar sheet of sp2 bonded carbon atoms packed in a honeycomb lattice, is considered to be the mother of all graphitic materials like fullerenes, carbon nanotubes, and graphite. Graphene has created tremendous interest to both physicists and chemists due to its various fascinating properties, both observed and predicted with possible potential applications in nanoelectronics, supercapacitors, solar cells, batteries, flexible displays, hydrogen storage, and sensors. In this paper, a brief overview on various aspects of graphene such as synthesis, functionalization, self-assembly, and some of its amazing properties along with its various applications ranging from sensors to energy storage devices had been illustrated.

Ionic Liquids: Potential Electrolytes for Electrochemical Applications

S. Zein El Abedin, K. S. Ryder, O. Höfft, and H. K. Farag — Wed, 19 Sep 2012 14:10:29 +0000

Forced Air-Breathing PEMFC Stacks

K. S. Dhathathreyan, N. Rajalakshmi, K. Jayakumar, and S. Pandian — Wed, 05 Sep 2012 09:37:32 +0000

Air-breathing fuel cells have a great potential as power sources for various electronic devices. They differ from conventional fuel cells in which the cells take up oxygen from ambient air by active or passive methods. The air flow occurs through the channels due to concentration and temperature gradient between the cell and the ambient conditions. However developing a stack is very difficult as the individual cell performance may not be uniform. In order to make such a system more realistic, an open-cathode forced air-breathing stacks were developed by making appropriate channel dimensions for the air flow for uniform performance in a stack. At CFCT-ARCI (Centre for Fuel Cell Technology-ARC International) we have developed forced air-breathing fuel cell stacks with varying capacity ranging from 50 watts to 1500 watts. The performance of the stack was analysed based on the air flow, humidity, stability, and so forth, The major advantage of the system is the reduced number of bipolar plates and thereby reduction in volume and weight. However, the thermal management is a challenge due to the non-availability of sufficient air flow to remove the heat from the system during continuous operation. These results will be discussed in this paper.

Theoretical Study on Solubility from Pt Electrocatalyst and Reactivity in Electrolyte Environment of Pt Complex in PEFC

Takayoshi Ishimoto and Michihisa Koyama — Thu, 30 Aug 2012 09:32:18 +0000

We theoretically analyzed the formation energy and solvation free energy of Pt(II) and Pt(IV) complexes with three types of ligands (H2O,OH−,andCF3SO3−) in electrolyte environment under the low- and high-humidity conditions to study the Pt electrocatalyst degradation and dissolution mechanisms for polymer electrolyte fuel cell. To represent the low- and high-humidity conditions in perfluorosulfonic acid (PFSA) polymer electrolyte membrane, we controlled the dielectric constant based on the experimental result. We observed general tendencies that the formation energy becomes larger while the solvation free energy becomes smaller under the low-humidity condition. The degradation of Pt complex from Pt surface is indicated to be accelerated by the adsorption of the end group of PFSA polymer side chain, on the Pt surface by comparing the desorption energies of [Pt(H2O)2(OH)3(CF3SO3)] and [Pt(H2O)2(OH)4]. The [Pt(H2O)4]2+ is not formed by the proton addition reaction between Pt complexes under the low-humidity condition of PFSA environment. From the analysis of possible reaction pathways of Pt complexes, we found the influence of humidity on the reactivity of Pt complex.

Diverse Role of Silicon Carbide in the Domain of Nanomaterials

T. Sahu, B. Ghosh, S. K. Pradhan, and T. Ganguly — Tue, 07 Aug 2012 14:13:18 +0000

Silicon carbide (SiC) is a promising material due to its unique property to adopt different crystalline polytypes which monitor the band gap and the electronic and optical properties. Despite being an indirect band gap semiconductor, SiC is used in several high-performance electronic and optical devices. SiC has been long recognized as one of the best biocompatible materials, especially in cardiovascular and blood-contacting implants and biomedical devices. In this paper, diverse role of SiC in its nanostructured form has been discussed. It is felt that further experimental and theoretical work would help to better understanding of the various properties of these nanostructures in order to realize their full potentials.

Simple Ion Transfer at Liquid|Liquid Interfaces

L. J. Sanchez Vallejo, J. M. Ovejero, R. A. Fernández, and S. A. Dassie — Tue, 10 Jul 2012 15:35:51 +0000

The main aspects related to the charge transfer reactions occurring at the interface between two immiscible electrolyte solutions (ITIES) are described. The particular topics to be discussed involve simple ion transfer. Focus is given on theoretical approaches, numerical simulations, and experimental methodologies. Concerning the theoretical procedures, different computational simulations related to simple ion transfer are reviewed. The main conclusions drawn from the most accepted models are described and analyzed in regard to their relevance for explaining different aspects of ion transfer. We describe numerical simulations implementing different approaches for solving the differential equations associated with the mass transport and charge transfer. These numerical simulations are correlated with selected experimental results; their usefulness in designing new experiments is summarized. Finally, many practical applications can be envisaged regarding the determination of physicochemical properties, electroanalysis, drug lipophilicity, and phase-transfer catalysis.

Simultaneous Determination of Hydroquinone, Catechol and Resorcinol at Graphene Doped Carbon Ionic Liquid Electrode

Li Ma and Guang-Chao Zhao — Tue, 19 Jun 2012 16:13:01 +0000

A new composite electrode has been prepared with doping graphene into the paste consisting graphite and ionic liquid, n-octyl-pyridinum hexafluorophosphate (OPFP). This electrode shows an excellent electrochemical activity for the redox of hydroquinone (HQ), catechol (CC), and resorcinol (RS). In comparison with bare paste electrode, the redox peaks of three isomers of dihydroxybenzene can be obviously, simultaneously observed at graphene doping paste electrode. Under the optimized condition, the simultaneous determination of HQ, CC, and RS in their ternary mixture can be carried out with a differential pulse voltammetric technique. The peak currents are linear to the concentration of HQ, CC, and RS in the range form 1×10−5 to 4×10−4, 1×10−5 to 3×10−4, and 1×10−6 to 1.7×10−4 mol L−1, respectively. The limits of detection are 1.8×10−6 mol L−1 for HQ, 7.4×10−7 mol L−1 for CC, and 3.6×10−7 M for RS, respectively.

Correlation between Quantumchemically Calculated LUMO Energies and the Electrochemical Window of Ionic Liquids with Reduction-Resistant Anions

Wim Buijs, Geert-Jan Witkamp, and Maaike C. Kroon — Mon, 14 May 2012 14:41:29 +0000

Quantum chemical calculations showed to be an excellent method to predict the electrochemical window of ionic liquids with reduction-resistant anions. A good correlation between the LUMO energy and the electrochemical window is observed. Surprisingly simple but very fast semiempirical calculations are in full record with density functional theory calculations and are a very attractive tool in the design and optimization of ionic liquids for specific purposes.

Reversible Deposition and Dissolution of Magnesium from Imidazolium-Based Ionic Liquids

QingSong Zhao, Yanna NuLi, Tuerxun Nasiman, Jun Yang, and JiuLin Wang — Wed, 09 May 2012 10:00:51 +0000

The electrochemical performance of six imidazolium cation-based ionic liquids (ILs) containing 0.3 mol L-1 Mg(CF3SO3)2 as the electrolytes for magnesium deposition-dissolution was examined by cyclic voltammogramms and constant current discharge-charge techniques. Scanning electron microscopy and energy dispersive X-ray spectroscopy measurements were conducted to characterize the morphologies and components of the deposits. The cathodic satiability of imidazolium cations can be improved by increasing the length of alkyls at the 1-position and introducing methyl group at the 2-position of the imidazolium cations. A reversible magnesium deposition-dissolution can be achieved at room temperature. After adding appreciate amount of tetrahydrofuran (THF) organic solvent, the conductivity and the peak currents for Mg deposition and dissolution can be significantly improved. The potential polarization of deposition-dissolution process is decreased using Mg powder electrode.

Voltammetric Study of the Copper Pentacyanonitrosylferrate Adsorbed on the Silica Modified with a Poly(propylene)imine Hexadecylamine Dendrimer for Determination of Nitrite

Tue, 08 May 2012 15:53:41 +0000

Poly(propylene)imine hexadecylamine dendrimer (DAB-Am-16) was anchored on the surface of 3-chloropropylsilyl silica gel and subsequently interacted with copper nitroprusside. The composite was characterized by infrared (FTIR), energy dispersive X-ray (EDX), and cyclic voltammetry. The above techniques confirmed the successful anchoring of the dendrimer on the silica gel modified surface and its interaction with copper nitroprusside. The cyclic voltammogram of CuNPSD was found to exhibit two redox couples with (Eθ′)1 = 0.30 V and (Eθ′)2 = 0.78 V versus Ag/AgCl (KCl=1.0 mol L−1; 𝑣=20 mV s−1) attributed to the redox processes Cu(I)/Cu(II) and Fe(II)(CN)5NO/Fe(III)(CN)5NO, respectively. The CuNPSD-modified graphite paste electrode was found to show a linear response of 5.0×10−4 to 9.0×10−3 mol L−1 for nitrite determination with a detection limit (DL) of 3.8×10−4 mol L−1 and an amperometric sensitivity of 25.0 mA/mol L−1. The CuNPSD-modified graphite paste electrode was found to show a good electrochemical stability and an excellent response to the electrocatalytic oxidation of sodium nitrite.

Lithium-Ion Batteries: Recent Advances and New Horizons

S. Gopukumar, Duncan H. Gregory, Hyun-Soo Kim, and Dong Shu — Thu, 19 Apr 2012 12:02:02 +0000

Tomato Quality during Short-Term Storage Assessed by Colour and Electronic Nose

Thu, 29 Mar 2012 09:57:22 +0000

An assay based on an electronic olfactory system was set to evaluate tomato fruits by sensing the aromatic volatiles during postharvest storage of 21 days at 19±0.5∘C in darkness. Olfactory system measurements were coupled with colour values. Odour profile and senescence parameters were carried out at 7-day intervals. Discriminant function analysis applied to electronic nose data showed three components, accounting for 99.2% of the total variance. In the present assay, separation among groups according to storage time (0, 7, and 14 days) was observed for wildtype. Overexpressed (Money Maker) lines/plants of tomato showed difference between odour profile for day 0 and day 21, even tough a no clear discrimination between 7 and 14 days was observed. Fruit lost weight almost linearly with shelf life (𝑃<0.001) presenting an averaged loss of 21% (𝑟2=0.98) for over-expressed (Money Maker) lines/plants, 13% (𝑟2=0.97) for silenced (Money Maker), and 14% (𝑟2=0.98) for wild type during 21 days of storage. Colour values 𝐿∗, 𝑎∗, and 𝑏∗ data showed that colour properties changed during storage for all the lines considered. Correlations between odour profiles and colour parameter were obtained showing that the electronic nose is a useful technique for monitoring short-term storage of tomato.

Prospects of Organic Conducting Polymer Modified Electrodes: Enzymosensors

Ravindra P. Singh — Tue, 27 Mar 2012 16:14:05 +0000

Organic conducting polymer modified electrodes (OCPMEs) have emerged as potential candidates for electrochemical biosensors due to their easy preparation methods along with unique properties, like stability in air and being compatible with biological molecules in a neutral aqueous solution. OCPMEs are playing an important role in the improvement of public health and environment for the detection of desired analytes with high sensitivity and specificity. In this paper, we highlight the prospects of OCMEs-based electrochemical enzymosensors.

Modification of Nafion Membranes by IL-Cation Exchange: Chemical Surface, Electrical and Interfacial Study

Sun, 25 Mar 2012 09:49:16 +0000

Bulk and surface changes in two proton-exchange membranes (Nafion-112 and Nafion-117) as a result of the incorporation of the IL-cation n-dodecyltriethylammonium (or DTA+) by a proton/cation exchange mechanism after immersion in a DTA+ aqueous solution were analysed by impedance spectroscopy (IS), differential scanning calorimetry (DSC), X-ray photoelectron spectroscopy (XPS), and contact angle measurements performed with dry samples of the original Nafion and Nafion-DTA+-modified membranes. Only slight differences were obtained in the incorporation degree and surface chemical nature depending on the membrane thickness, and DTA+ incorporation modified both the hydrophobic character of the original Nafion membranes and their thermal stability. Electrical characterization of the dry Nafion-112 membrane was performed by impedance spectroscopy while different HCl solutions were used for membrane potential measurements. A study of time evolution of the impedance curves measured in the system “IL aqueous solution/Nafion-112 membrane/IL aqueous solution” was also performed. This study allows us monitoring the electrical changes associated to the IL-cation incorporation in both the membrane and the membrane/IL solution interface, and it provides supplementary information on the characteristic of the Nafion/DTA+ hybrid material. Moreover, the results also show the significant effect of water on the electrical resistance of the Nafion-112/IL-cation-modified membrane.

Theory of Square-Wave Voltammetry of Two-Electron Reduction with the Adsorption of Intermediate

Milivoj Lovrić and Šebojka Komorsky-Lovrić — Thu, 22 Mar 2012 11:05:05 +0000

Thermodynamically unstable intermediate of fast and reversible two-electron electrode reaction can be stabilized by the adsorption to the electrode surface. In square-wave voltammetry of this reaction mechanism, the split response may appear if the electrode surface is not completely covered by the adsorbed intermediate. The dependence of the difference between the net peak potentials of the prepeak and postpeak on the square-wave frequency is analyzed theoretically. This relationship can be used for the estimation of adsorption constant.

High Tap Density Spherical Li[Ni𝟎.𝟓Mn𝟎.𝟑Co𝟎.𝟐]O𝟐 Cathode Material Synthesized via Continuous Hydroxide Coprecipitation Method for Advanced Lithium-Ion Batteries

Shunyi Yang, Xianyou Wang, Xiukang Yang, Ziling Liu, Qiliang Wei, and Hongbo Shu — Thu, 22 Mar 2012 10:52:42 +0000

Spherical [Ni0.5Mn0.3Co0.2](OH)2 precursor with narrow size distribution and high tap density has been successfully synthesized by a continuous hydroxide coprecipitation, and Li[Ni0.5Mn0.3Co0.2]O2 is then prepared by mixing the precursor with 6% excess Li2CO3 followed by calcinations. The tap density of the obtained Li[Ni0.5Mn0.3Co0.2]O2 powder is as high as 2.61 g cm−3. The powders are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), particle size distribution (PSD), and charge/discharge cycling. The XRD studies show that the prepared Li[Ni0.5Mn0.3Co0.2]O2 has a well-ordered layered structure without any impurity phases. Good packing properties of spherical secondary particles (about 12 μm) consisted of a large number of tiny-thin plate-shape primary particles (less than 1 μm), which can be identified from the SEM observations. In the voltage range of 3.0–4.3 V and 2.5–4.6 V, Li[Ni0.5Mn0.3Co0.2]O2 delivers the initial discharge capacity of approximately 175 and 214 mAh g−1 at a current density of 32 mA g−1, and the capacity retention after 50 cycles reaches 98.8% and 90.2%, respectively. Besides, it displays good high-temperature characteristics and excellent rate capability.

Enhanced Supercapacitance of Hydrous Ruthenium Oxide/Mesocarbon Microbeads Composites toward Electrochemical Capacitors

Changzhou Yuan, Linrui Hou, Diankai Li, Long Yang, and Jiaoyang Li — Tue, 20 Mar 2012 14:25:14 +0000

A facile hydrothermal strategy was proposed to synthesize RuO2·nH2O/mesocarbon microbeads (MCMBs) composites. Further physical characterizations revealed that RuO2·nH2O nanoparticles (NPs) were well dispersed upon the surfaces of the MCMB pretreated in 6 M KOH solution. Electrochemical data indicated that the RuO2·nH2O/MCMB composites owned higher electrochemical utilization of RuO2 species, better power property, and better electrochemical stability, compared with the single RuO2 phase. The good dispersion of RuO2·nH2O NPs and enhanced electronic conductivity made the H+ ions and electrons easily contact the RuO2·nH2O phase for efficient energy storage at high rates.

Electrochemical Sensors and Biosensors

Farnoush Faridbod, Vinod Kumar Gupta, and Hassan Ali Zamani — Thu, 15 Mar 2012 09:59:40 +0000

Electrocatalysis: Fundamentals and Applications

Mon, 12 Mar 2012 10:01:24 +0000

Prussian Blue Modified Solid Carbon Nanorod Whisker Paste Composite Electrodes: Evaluation towards the Electroanalytical Sensing of H2O2

Mon, 12 Mar 2012 09:29:53 +0000

Metallic impurity free solid carbon nanorod “Whiskers” (SCNR Whiskers), a derivative of carbon nanotubes, are explored in the fabrication of a Prussian Blue composite electrode and critically evaluated towards the mediated electroanalytical sensing of H2O2. The sensitivity and detection limits for H2O2 on the paste electrodes containing 20% (w/w) Prussian Blue, mineral oil, and carbon nanorod whiskers were explored and found to be 120 mA/(M cm2) and 4.1 μM, respectively, over the concentration range 0.01 to 0.10 mM. Charge transfer constant for the 20% Prussian Blue containing SCNR Whiskers paste electrode was calculated, for the reduction of Prussian Blue to Prussian White, to reveal a value of 1.8±0.2 1/s (𝛼=0.43, 𝑁=3). Surprisingly, our studies indicate that these metallic impurity-free SCNR Whiskers, in this configuration, behave electrochemically similar to that of an electrode constructed from graphite.

Ethanol Electrooxidation on Pt with Lanthanum Oxide as Cocatalyst in a DAFC

Thu, 01 Mar 2012 11:09:57 +0000

Electrocatalytic activity toward ethanol electrooxidation of Pt particles in PtLa/C catalysts with different Pt : La ratios has been studied with different electrochemical and spectroscopic techniques, and the results were compared to those of Pt/C catalyst. Significant enhancement in the electrocatalytic activity has been achieved by depositing the Pt particles with lanthanum oxides/hydroxides using an alcohol reduction method. Compared to Pt/C catalyst, PtLa/C materials exhibit a lower onset potential and a higher electron-transfer rate constant for the investigated reaction. These studies illustrate the possibility of utilizing Pt/C with La oxides/hidroxides as electrocatalyst for direct alcohol fuel cells (DAFCs).

Electronic Nose for Microbiological Quality Control of Food Products

Tue, 28 Feb 2012 13:15:38 +0000

Electronic noses (ENs) have recently emerged as valuable candidates in various areas of food quality control and traceability, including microbial contamination diagnosis. In this paper, the EN technology for microbiological screening of food products is reviewed. Four paradigmatic and diverse case studies are presented: (a) Alicyclobacillus spp. spoilage of fruit juices, (b) early detection of microbial contamination in processed tomatoes, (c) screening of fungal and fumonisin contamination of maize grains, and (d) fungal contamination on green coffee beans. Despite many successful results, the high intrinsic variability of food samples together with persisting limits of the sensor technology still impairs ENs trustful applications at the industrial scale. Both advantages and drawbacks of sensor technology in food quality control are discussed. Finally, recent trends and future directions are illustrated.

Direct Alcohol Fuel Cell

Changwei Xu, Pei-Kang Shen, Dingsheng Yuan, and Shuangyin Wang — Sun, 26 Feb 2012 18:43:59 +0000

Surface Electrochemistry: Structured Electrode, Synthesis, and Characterization

Fethi Bedioui, Tebello Nyokong, and José H. Zagal — Sun, 26 Feb 2012 15:09:42 +0000