bluuebunny/crossref_metadata_2025 huggingface dataset:
A Complex Permittivity Based Sensor for the Electrical Characterization of High-Voltage Transformer Oils
Authors: Dervos Constantine  T. , Paraskevas Christos  D. , Skafidas Panayotis  D. , Vassiliou Panayota
Published: October 2008

This work investigates the use of a specially designed cylindrical metal cell, inorder to obtain complex permittivity and tanδ data of highly insulating High Voltage (HV)transformer oil samples. The data are obtained at a wide range of frequencies and operationtemperatures to demonstrate the polarization phenomena and the thermally stimulatedeffects. Such complex permittivity measurements may be utilized as a criterion for theservice life prediction of oil field electrical equipment (OFEE). Therefore, by one set ofmeasurements on a small oil volume, data may be provided on the impending termination,or continuation of the transformer oil service life. The oil incorporating cell, attached to theappropriate measuring units, could be described as a complex permittivity sensor. In thiswork, the acquired dielectric data from a great number of operating distribution networkpower transformers were correlated to corresponding physicochemical ones to demonstratethe future potential employment of the proposed measuring technique.
Long-Term Monitoring of Brain Dopamine Metabolism In Vivo with Carbon Paste Electrodes
Authors: O’Neill Robert D.
Published: October 2008

This review focuses on the stability of voltammetric signals recorded overperiods of months with carbon paste electrodes (CPEs) implanted in the brain. The keyinteraction underlying this stability is between the pasting oil and brain lipids that arecapable of inhibiting the fouling caused by proteins. In brain regions receiving a significantdopaminergic input, a peak due to the methylated metabolites of dopamine, principallyhomovanillic acid (HVA), is clearly resolved using slow sweep voltammetry. Although anumber of factors limit the time resolution for monitoring brain HVA concentrationdynamics, the stability of CPEs allows investigations of long-term effects of drugs, as wellas behavioral studies, not possible using other in-vivo monitoring techniques.
Special Issue Preface, DNA Based Sensors
Authors: Labuda Jan
Published: October 2008

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Development of a DNA Sensor Based on Alkanethiol Self- Assembled Monolayer-Modified Electrodes
Authors: Loaiza Óscar A. , Campuzano Susana , López-Berlanga María , Pedrero María , Pingarrón José M.
Published: October 2008

An electrochemical DNA biosensor based on recognition of double or singlestranded DNA (ds-DNA/ss-DNA) immobilised on a self-assembled modified gold electrodeis presented for denaturalisation and hybridisation detection. DNA is covalently bond on aself assembled 3-mercaptopropionic acid monolayer by using water soluble N-3-(dimethylaminopropyl)-N´ethylcarbodiimide hydrochloride (EDC) and Nhydroxisulfosuccinimide(NHSS) as linkers. The interaction between the immobilised DNAand methylene blue (MB) is investigated using square wave voltammetry (SWV). Theincrease or diminution of peak currents of the MB upon the hybridisation or denaturalisationevent at the modified electrode surface is studied.
Amperometric DNA-Peroxidase Sensor for the Detection of Pharmaceutical Preparations
Authors: Evtugyn G. A. , Goldfarb O. E. , Budnikov H. C. , Ivanov A. N. , Vinter V. G.
Published: October 2008

Novel DNA-sensor with enzymatic amplification of the signal has beendeveloped on the base of glassy carbon electrode modified with ds-DNA and horseradishperoxidase (HRP). Phenothiazine dyes Methylene Blue and Methylene Green were used aselectrochemical markers for the detection of sulfonamide and anthracycline preparationsable to interact with DNA. The biosensor signal related to HRP oxidation of the markersdepends on the relation between their bonded and readily oxidized forms which depends onthe nature and concentration of pharmaceuticals. Sulfonamides diminish surfaceconcentration of MB accessible for HRP reaction whereas anthracyclines releaseintercalated marker and increase the signal. The DNA-HRP sensor developed makes itpossible to detect down to 0.002 nmol L-1 of sulfamethoxazole, 0.1 nmol L-1 of sulfadiazine,0.01 nmol L-1 of sulfamethazine, 0.1 nmol L-1 of sulfaguanine, 0.05 μmol L-1 of rubomycinand 0.08 μmol L-1 of doxorubicin.
Electrochemical DNA Sensors for Detection of DNA Damage
Authors: Diculescu Victor Constantin , Paquim Ana-Maria Chiorcea , Brett Ana Maria Oliveira
Published: October 2008

Electrochemical devices have received particular attention due to their rapiddetection and great sensitivity for the evaluation of DNA-hazard compounds interactionmechanisms. Several types of bioanalytical method use nucleic acids probes to detect DNAdamage. This article reviews current directions and strategies in the development andapplications of electrochemical DNA sensors for the detection of DNA damage.
DNA Biosensor for Rapid Detection of Genotoxic Compounds in Soil Samples
Authors: Bagni Graziana , Hernandez Silvia , Mascini Marco , Sturchio Elena , Boccia Priscilla , Marconi Simona
Published: October 2008

An electrochemical DNA-based biosensor is proposed as a fast and easyscreening method for the detection of genotoxic compounds in soil samples. The biosensorwas assembled by immobilising double stranded Calf thymus DNA on screen-printedelectrodes. The interactions between DNA and environmental pollutants can causevariations of the electrochemical proprieties of DNA when they cause a DNA damage.Preliminary studies were performed using benzene, naphthalene and anthracene derivativesas model compounds. The effect of these compounds on the surface-confined DNA wasfound to be linearly related to their concentration in solution. On the other hand, theobjective was to optimise the ultrasonic extraction conditions of these compounds fromartificially spiked soil samples. Then, the applicability of such a biosensor was evaluated byanalysing soil samples from an Italian region with ecological risk (ACNA of Cengio, SV).DNA biosensor for qualitative analysis of soil presented a good correlation with a semiquantitativemethod for aromatic ring systems determination as fixed wavelengthfluorescence and interestingly, according results were found also with other bioassays.This kind of biosensors represent a new, easy and fast way of analysis of polluted sites, therefore they can be used as early warnings devices in areas with ecological risk as in situ measurement.
Voltammetric Detection of Damage to DNA by Arsenic Compounds at a DNA Biosensor
Authors: Labuda J. , K. Bubnicova K. , Kovalova L. , Vanickova M. , Mattusch J. , Wennrich R.
Published: October 2008

DNA biosensor can serve as a powerfull tool for simple in vitro tests of chemicaltoxicity. In this paper, damage to DNA attached to the surface of screen-printed carbonelectrode by arsenic compounds in solution is described. Using the Co(III) complex with1,10-phenanthroline, [Co(phen)3]3+ , as an electrochemical DNA marker and the Ru(II)complex with bipyridyne, [Ru(bipy)3]2+ , as a DNA oxidation catalyst, the portion of originaldsDNA which survives an incubation of the biosensor in the cleavage medium was evaluated.The model cleavage mixture was composed of an arsenic compound at 10-3 mol/Lconcentration corresponding to real contaminated water, 2x10-4 mol/L Fe(II) or Cu(II) ions asthe redox catalyst, and 1.5x10-2 mol/L hydrogen peroxide. DNA damage by arsenite,dimethylarsinic acid as the metabolic product of inorganic arsenic and widely used herbicide,as well as phenylarsonic acid and p-arsanilic acid as the representatives of feed additives wasfound in difference to arsenate.
Immobilization of DNA at Glassy Ccarbon Electrodes: A Critical Study of Adsorbed Layer
Authors: Pedano M. L. , Rivas G. A.
Published: October 2008

In this work we present a critical study of the nucleic acid layer immobilized atglassy carbon electrodes. Different studies were performed in order to assess the nature of theinteraction between DNA and the electrode surface. The adsorption and electrooxidation of DNAdemonstrated to be highly dependent on the surface and nature of the glassy carbon electrode. TheDNA layer immobilized at a freshly polished glassy carbon electrode was very stable even afterapplying highly negative potentials. The electron transfer of potassium ferricyanide, catechol anddopamine at glassy carbon surfaces modified with thin (obtained by adsorption under controlledpotential conditions) and thick (obtained by casting the glassy carbon surface with highly concentratedDNA solutions) DNA layers was slower than that at the bare glassy carbon electrode, although thiseffect was dependent on the thickness of the layer and was not charge selective. Raman experimentsshowed an important decrease of the vibrational modes assigned to the nucleobases residues,suggesting a strong interaction of these residues with the electrode surface. The hybridization ofoligo(dG)21 and oligo(dC)21 was evaluated from the guanine oxidation signal and the reduction of theredox indicator Co(phen)33+ . In both cases the chronopotentiometric response indicated that thecompromise of the bases in the interaction of DNA with the electrode surface is too strong, preventingfurther hybridization. In summary, glassy carbon is a useful electrode material to detect DNA in adirect and very sensitive way, but not to be used for the preparation of biorecognition layers by directadsorption of the probe sequence on the electrode surface for detecting the hybridization event.
Elimination Voltammetry with Linear Scan as a New Detection Method for DNA Sensors
Authors: Trnkova Libuse , Jelen Frantisek , Petrlova Jitka , Adam Vojtech , Potesil David , Kizek Rene
Published: October 2008

The paper describes successful coupling of adsorptive transfer stripping (AdTS) andelimination voltammetry with linear scan (EVLS) for the resolution of reduction signals of cytosine (C)and adenine (A) residues in hetero-oligodeoxynucleotides (ODNs). Short ODNs (9-mers and 20-mers)were adsorbed from a small volume on a hanging mercury drop electrode (HMDE). After washing ofthe ODN-modified electrode by water and its transferring to an electrochemical cell, voltammetric curves were measured. The AdTS EVLS was able to determine of C/A ratio of ODNs through theelimination function conserving the diffusion current component and eliminating kinetic and chargingcurrent components. This function, which provides the elimination signal in a peak-counterpeak form,increased the current sensitivity for A and C resolution, and for the recognition of bases sequences inODN chains. Optimal conditions of elimination experiments such as pH, time of adsorption, and scanrate were found. The combination of EVLS with AdTS procedure can be considered as a newdetection method in a DNA sensor.
Potentiometric CO2 Sensor Using Li Ion Conducting Li3PO4Thin Film Electrolyte
Authors: Noh Whyo  Sub , Satyanarayana L. , Park Jin  Seong
Published: October 2008

Li+ ion conducting Li3PO4 thin film electrolytes with thickness 300nm, 650nm and1.2μm were deposited on Al2O3 substrate at room temperature by thermal evaporation method.Reference and sensing electrodes were printed on Au interfaces by conventional screen printingtechnique. The overall dimension of the sensor was 3 x 3 mm and of electrodes were 1 x 1.5 mmeach. The fabricated solid state potentiometric CO2 sensors of type: CO2, O2, Au, Li2TiO3-TiO2 / Li3PO4 / Li2CO3, Au, CO2, O2 have been investigated for CO2 sensing properties. Theelectromotive force (emf) and δemf/dec values of the sensors are dependent on the thickness ofthe electrolyte film. 1.2μm thickness deposited sensor has shown good sensing behavior than thesensors with less thickness. The δemf values of the sensor are linearly increased up to 460oCoperating temperature and became stable above 460oC. Between 460-500oC temperatures regionthe sensor has reached an equilibrium state and the experimentally obtained δemf values areabout 80% of the theoretically calculated values. A Nernst’s slope of -61mV/decade has beenobtained between 250 to 5000 ppm of CO2 concentration at 500oC temperature. The sensor issuitable for ease of mass production in view of its miniaturization and cost effectiveness aftersome further improvement.
Brain Tissue Oxygen: In Vivo Monitoring with Carbon Paste Electrodes
Authors: Bolger Fiachra B. , Lowry John P.
Published: October 2008

In this communication we review selected experiments involving the use ofcarbon paste electrodes (CPEs) to monitor and measure brain tissue O2 levels in awakefreely-moving animals. Simultaneous measurements of rCBF were performed using the H2clearance technique. Voltammetric techniques used include both differential pulse (O2) andconstant potential amperometry (rCBF). Mild hypoxia and hyperoxia produced rapidchanges (decrease and increase respectively) in the in vivo O2 signal. Neuronal activation(tail pinch and stimulated grooming) produced similar increases in both O2 and rCBFindicating that CPE O2 currents provide an index of increases in rCBF when such increasesexceed O2 utilization. Saline injection produced a transient increase in the O2 signal whilechloral hydrate produced slower more long-lasting changes that accompanied the behavioralchanges associated with anaesthesia. Acetazolamide increased O2 levels through an increasein rCBF.
Robust Multivariable Estimation of the Relevant Information Coming from a Wheel Speed Sensor and an Accelerometer Embedded in a Car under Performance Tests
Authors: Hernandez Wilmar
Published: October 2008

In the present paper, in order to estimate the response of both a wheel speedsensor and an accelerometer placed in a car under performance tests, robust and optimalmultivariable estimation techniques are used. In this case, the disturbances and noisescorrupting the relevant information coming from the sensors’ outputs are so dangerous thattheir negative influence on the electrical systems impoverish the general performance of thecar. In short, the solution to this problem is a safety related problem that deserves our fullattention. Therefore, in order to diminish the negative effects of the disturbances and noiseson the car’s electrical and electromechanical systems, an optimum observer is used. Theexperimental results show a satisfactory improvement in the signal-to-noise ratio of therelevant signals and demonstrate the importance of the fusion of several intelligent sensordesign techniques when designing the intelligent sensors that today’s cars need.
Softlithography in Chemical Sensing – Analytes from Molecules to Cells
Authors: Lieberzeit Peter  A. , Glanznig Gerd , Jenik Michael , Sylwia Gazda-Miarecka Sylwia , Dickert Franz  L. , Leidl Anton
Published: October 2008

Imprinting is a flexible and straightforward technique to generate selective sensormaterials e.g. for mass-sensitive detection. Inherently, the strategy suits both molecularanalytes and entire micro organisms or cells. Imprinted polyurethanes e.g. are capable ofdistinguishing the different xylene isomers with very appreciable selectivity factors.Combining imprinted titanates with surface transverse wave resonators (STW) leads to apowerful tool for detecting engine oil degradation, which is an excellent example foroxidative deterioration processes in a highly complex matrix. Surface imprints withgeometrically equal cavities exhibit clear chemical selectivity, as can e.g. be seen throughthe example of different human rhinovirus (HRV) serotypes. Another example is a bloodgroup-selective sensor prepared by templating with erythrocyte ghosts. Both the bloodgroupA and B imprinted material selectively distinguish between blood groups A, B and O,whereas no difference in sensor signal has been observed for AB, where both blood groupantigen types are present on the cell surface.
Surface Morphology and Sensing Property of NiO-WO3 Thin Films Prepared by Thermal Evaporation
Authors: Na Dong-myong , Satyanarayana L. , Choi Gwang-Pyo , Shin Yong-Jin , Park Jin  Seong
Published: October 2008

WO3 and NiO-WO3 thin films of various thicknesses were deposited on anAl2O3-Si (alumina-silicon) substrate using high vacuum thermal evaporation. Afterannealing at 500oC for 30 minutes in air, the crystallanity and surface morphology of WO3and NiO-WO3 thin films were investigated using X-ray diffraction (XRD) and ScanningElectron Microscopy (SEM). It is observed that the WO3 thin films were resulted in cracksbetween the polycrystalline grains and the grain growth was increased with increasingthickness causing deteriorated sensing characteristics of the films. On the other hand, anoptimum deposition of NiO on WO3 thin film has inhibited the grain growth and improvedthe sensitivity of the films. The inhibition is limited to a certain thickness of WO3 and NiOcontent (mol %) of inclusion and below or above this limitation the grain growth could notbe suppressed. Moreover, the deposition sequence of NiO and WO3 is also playing asignificant role in controlling the grain growth. A probable mechanism for the control ofgrain growth and improving the sensing property has been discussed.
Classification of Chinese Yellow Wines by ChemometricAnalysis of Cyclic Voltammogram of Copper Electrodes
Authors: Wu Jian , Liu Jun , Fu Min , Li Guang , Lou Zhengguo
Published: October 2008

A Chinese yellow wine classification method is proposed based on chemometricanalysis of voltammogram of copper electrode. The main components in Chinese yellowwine are alcohol, amino acids and carbon hydrates. In strong alkaline solution copperelectrode shows rich voltammetric responses to these components. Principal componentanalysis is employed to analyse voltammetric response of copper electrode to six Chinesewine samples in strong alkaline solution. The score plots show good discrimination of thesewine samples. In order to compress the original voltammetric data, a windowed time slicingmethod is investigated in this study. It greatly reduces the input data number and theresulted PCA plot still has good discrimination ability.
Amperometric Detection of Nitric Oxide with Microsensor in the Medium of Seawater and Its Applications
Authors: Xing Lei , Zhang Zheng-Bin , Liu Chun-Ying , Wu Zhen-Zhen , Lin Cai
Published: October 2008

Amperometric detection of nitric oxide with ISO-NOPMC NO microsensors(WPI) is systemically studied in the six media including seawater. The linear range of themicrosensor for NO was from 10-6 to 10-9 mol/l and the detection limit was4.2×10-10 mol/L(S/N=2). With this method, we provide preliminary evidence that NOproduction could be a general attribute of marine alga (Haeterosigma akashiwo).Experiment conducted with inhibitor of uncoupler 2,4-DNP (2,4-dinitropheno) revealed thatNR (nitrate reductase) activity is responsible for NO formation.
Novel Planar Electromagnetic Sensors: Modeling and Performance Evaluation
Authors: Mukhopadhyay Subhas  C.
Published: October 2008

High performance planar electromagnetic sensors, their modeling and a fewapplications have been reported in this paper. The researches employing planar typeelectromagnetic sensors have started quite a few years back with the initial emphasis on theinspection of defects on printed circuit board. The use of the planar type sensing system hasbeen extended for the evaluation of near-surface material properties such as conductivity,permittivity, permeability etc and can also be used for the inspection of defects in the nearsurfaceof materials. Recently the sensor has been used for the inspection of quality ofsaxophone reeds and dairy products. The electromagnetic responses of planar interdigitalsensors with pork meats have been investigated.
Improvement of Amperometric Sensor Used for Determination of Nitrate with Polypyrrole Nanowires Modified Electrode
Authors: Zhang Xiu-ling , Wang Ji-xiao , Wang Zhi , Wang Shi-chang
Published: October 2008

Polypyrrole(PPy) nanowire modified electrodes were developed by template-freeelectrochemical method based on graphite electrode. The modified electrode wascharacterized by their amperometric response towards nitrate ions. Before reduction ofnitrate ions, electrochemical solid-phase extraction (EC-SPE) of nitrate in/on modifiedelectrodes was conducted. It is found that the unusual nanowired structure of polypyrrolelayer (instead of well known cauliflower structure) allows us to increase the effectivesurface area of the electrode and subsequently the sensitivity. And the effects ofelectrochemical preparation parameters of PPy nanowire modified electrodes on theircorresponding characters were evaluated. The experimental results show that theelectrochemical preparation parameters of the modified electrodes such as scan rate,polymerization potential, temperature of polymerization solution and polymerization timehave significantly effects on the morphology of PPy nanowires and subsequently effectivesurface area of the electrode and electroreduction current density of nitrate. Thedetermination sensitivity may be varied according to the modification parameters. Under acertain polymerization conditions, the corresponding sensitivity reaches 336.28 mA/M cm2 and the detection limit is 1.52×10-6 M. The proposed method was successfully applied in thedetection of nitrate in the real samples.
Photo-Induced Unpinning of Fermi Level in WO3
Authors: Malagù Cesare , Carotta Maria  C. , Comini Elisabetta , Faglia Guido , Giberti Alessio , Guidi Vincenzo , Maffeis Thierry  G.G. , Martinelli Giuliano , Sberveglieri Giorgio , Wilks Steve  P.
Published: October 2008

Atomic force and high resolution scanning tunneling analyses were carried out onnanostructured WO3 films. It turned out that the band gap measured by scanning tunnelingspectroscopy at surface is lower than the band gap reported in the literature. This effect isattributed to the high density of surface states in this material, which allows tunneling intothese states. Such a high density of surface states pins the Fermi level resulting in modestsurface activity at room temperature. Photo activation of WO3 results in unpinning of theFermi level and thereby in higher chemical activity at surface.
Determination of Atropine in Injection with β-Cyclodextrin Modified Ion Sensitive Field Effect Transistor Sensor
Authors: Li Xian-Wen , Yang Bo-Lun , Wu Ying-Ying , Lin Hong-Ye
Published: October 2008

A new atropine drug-FET sensor, which was made of an ISFET (ion sensitivefield effect transistor) and a drug sensitive membrane prepared by adding electric activematter to a β-cyclodextrin solution, was developed. The pH influence, selectivity, responsecurve, reproducibility, stability, response time and life of this sensor were investigated. Apreliminary application of the sensor was discussed as well. The experimental resultsindicated that the sensor showed a Nernst response to atropine with a slope of 58.0mV/decade over the concentration range of 5.0×10-3 － 1.0×10-6 mol/L and the pH rangeof 5.0－8.5. The sensor detection limit was 8.0×10-7 mol/L. The performance of this sensorwas very stable when it was used to determine atropine concentration in a medicinalinjection. The obtained results agreed well with the pharmacopoeia method.
Improving the Response of a Rollover Sensor Placed in a Car under Performance Tests by Using a RLS Lattice Algorithm
Authors: Hernandez Wilmar
Published: October 2008

In this paper, a sensor to measure the rollover angle of a car under performance testsis presented. Basically, the sensor consists of a dual-axis accelerometer, analog-electronicinstrumentation stages, a data acquisition system and an adaptive filter based on a recursiveleast-squares (RLS) lattice algorithm. In short, the adaptive filter is used to improve theperformance of the rollover sensor by carrying out an optimal prediction of the relevant signalcoming from the sensor, which is buried in a broad-band noise background where we have littleknowledge of the noise characteristics. The experimental results are satisfactory and show asignificant improvement in the signal-to-noise ratio at the system output.
Determination of the Temperature Change by Means of an Outcoming Signal of Electric Resistance in an Isoperibolic Calorimetric Cell. Obtainment of Heat Solution
Authors: Giraldo-Gutierréz Liliana , Moreno-Piraján Juan Carlos
Published: October 2008

An isoperibolic calorimetric cell is built with glass surrounded by plastic insulation. Thecell has a lid on which a thermistor thermometer, an electric resistance to provide the cell with definitequantities of electric work and a container for a glass ampoule, are placed. For measuring the thermalchanges, an NTC thermistor, which provides an electric resistance signal that varies with temperature,is used. Calibration curves of the thermistor and of the stabilization of the system signal in thermalequilibrium are shown, which enable the observation of a good insulation. The calorific capacity of thesystem with water, with a value of 206.7 ± 0.7 J °C-1 is determined; the solution enthalpy for propanolwaterand KCl-water systems is obtained, which shows the behavior of the cell before exothermic andendothermic effects, respectively.
Nonlinear Least-Squares Based Method for Identifying and Quantifying Single and Mixed Contaminants in Air with an Electronic Nose
Authors: Zhou Hanying , Homer Margie  L. , Shevade Abhijit V. , Ryan Margaret  A.
Published: October 2008

The Jet Propulsion Laboratory has recently developed and built an electronic nose(ENose) using a polymer-carbon composite sensing array. This ENose is designed to be usedfor air quality monitoring in an enclosed space, and is designed to detect, identify andquantify common contaminants at concentrations in the parts-per-million range. Itscapabilities were demonstrated in an experiment aboard the National Aeronautics and SpaceAdministration’s Space Shuttle Flight STS-95. This paper describes a modified nonlinearleast-squares based algorithm developed to analyze data taken by the ENose, and itsperformance for the identification and quantification of single gases and binary mixtures oftwelve target analytes in clean air. Results from laboratory-controlled events demonstrate theeffectiveness of the algorithm to identify and quantify a gas event if concentration exceedsthe ENose detection threshold. Results from the flight test demonstrate that the algorithmcorrectly identifies and quantifies all registered events (planned or unplanned, as singles ormixtures) with no false positives and no inconsistencies with the logged events and theindependent analysis of air samples.
Virtual Instrument for an Automated Potentiometric e-Tongue Employing the SIA Technique
Authors: Durán Alejandro , Cortina Montserrat , Velasco Lya , Rodríguez José Antonio , Alegret Salvador , Del Valle Manuel
Published: October 2008

In this work we report the design, construction, and applications of an electronictongue (abbreviated e-tongue) based on an array of potentiometric sensors employing theSequential Injection Analysis technique (SIA) operated as a Virtual Instrument implementedin LabVIEW6.1TM. The system can use transient and stationary responses as the measuredinput information for e-tongues. The new concepts applied, lead to different advantages tobe obtained, such as complete automation, easy handling, saving time, reliability andmodularity.
LON Technology in Wireless Sensor Networking Applications
Authors: Miskowicz Marek , Golanski Ryszard
Published: October 2008

In the paper a discussion on how to optimize LonWorks/EIA-709 sensornetworking technology for wireless applications, in presented. Main solutions offered byLocal Operating Networks (LON, LonWorks) platform attractive for wirelesscommunication, that is, the send-on-delta concept and the sleep mode, are displayed. Thepredictive p-persistent CSMA MAC protocol constituting the heart of the communicationcapability of LON networks is analysed in detail. Next, the message services are described,and the analytical evaluation of delivery reliability is derived. Performance evaluation basedon simulation results for unicast traffic is presented first. In order to highlight the robustnessof the predictive CSMA to overload situations, the saturation performance for a general caseload scenario including multicast transactions is reported. The methods of effectivemanagement of energy consumption in LonWorks networks are discussed. Finally, the LONdesign tradeoffs are summarized.
Send-On-Delta Concept: An Event-Based Data Reporting Strategy
Authors: Miskowicz Marek
Published: October 2008

The paper addresses the issue of the send-on-delta data collecting strategy tocapture information from the environment. Send-on-delta concept is the signal-dependenttemporal sampling scheme, where the sampling is triggered if the signal deviates by deltadefined as the significant change of its value. It is an attractive scheme for wireless sensornetworking due to effective energy consumption. The quantitative evaluations of send-on-delta scheme for a general type continuous-time bandlimited signal are presented in thepaper. The bounds on the mean traffic of reports for a given signal, and assumed samplingresolution, are evaluated. Furthermore, the send-on-delta effectiveness, defined as thereduction of the mean rate of reports in comparison to the periodic sampling for a givenresolution, is derived. It is shown that the lower bound of the send-on-delta effectiveness(i.e. the guaranteed reduction) is independent of the sampling resolution, and constitutes thebuilt-in feature of the input signal. The calculation of the effectiveness for standard signals,that model the state evolution of dynamic environment in time, is exemplified. Finally, theexample of send-on-delta programming is shown.
Improving the Response of a Wheel Speed Sensor by Using a RLS Lattice Algorithm
Authors: Hernandez Wilmar
Published: October 2008

Among the complete family of sensors for automotive safety, consumer andindustrial application, speed sensors stand out as one of the most important. Actually, speedsensors have the diversity to be used in a broad range of applications. In today’s automotiveindustry, such sensors are used in the antilock braking system, the traction control systemand the electronic stability program. Also, typical applications are cam and crank shaftposition/speed and wheel and turbo shaft speed measurement. In addition, they are used tocontrol a variety of functions, including fuel injection, ignition timing in engines, and so on.However, some types of speed sensors cannot respond to very low speeds for differentreasons. What is more, the main reason why such sensors are not good at detecting very lowspeeds is that they are more susceptible to noise when the speed of the target is low. In short,they suffer from noise and generally only work at medium to high speeds. This is one of thedrawbacks of the inductive (magnetic reluctance) speed sensors and is the case under study.Furthermore, there are other speed sensors like the differential Hall Effect sensors that arerelatively immune to interference and noise, but they cannot detect static fields. This limitstheir operations to speeds which give a switching frequency greater than a minimumoperating frequency. In short, this research is focused on improving the performance of avariable reluctance speed sensor placed in a car under performance tests by using arecursive least-squares (RLS) lattice algorithm. Such an algorithm is situated in an adaptivenoise canceller and carries out an optimal estimation of the relevant signal coming from thesensor, which is buried in a broad-band noise background where we have little knowledgeof the noise characteristics. The experimental results are satisfactory and show a significantimprovement in the signal-to-noise ratio at the system output.
Electrochemical Behavior of Epinephrine at a Glassy Carbon Electrode Modified by Electrodeposited Films of Caffeic Acid
Authors: Ren Wang , Luo Hong  Qun , Li Nian  Bing
Published: October 2008

A stable electroactive thin film of poly(caffeic acid) has been deposited on thesurface of a glassy carbon electrode by potentiostatic technique in an aqueous solutioncontaining caffeic acid. The voltammetric behavior of epinephrine (EP) at the poly(caffeicacid) modified glassy carbon electrode was studied by cyclic voltammetry. The poly(caffeicacid) modified electrode exhibited a promotion effect on the oxidation of EP. In a pH 7.4phosphate buffer, the anodic current increased linearly with the concentration of EP in therange from 2.0 × 10−6 to 3.0 × 10−4 mol L−1 and the detection limit for EP was 6.0 × 10−7mol L−1. The proposed method can be applied to the determination of EP in practicalinjection samples with simplicity, rapidness and accurate results.
An EMI Filter Selection Method Based on Spectrum of Digital Periodic Signal
Authors: Podbersic Marko , Matko Vojko , Segula Matjaz
Published: October 2008

This paper describes a new method for the selection of an appropriate signal lineElectromagnetic Interference (EMI) filter. To date, EMI filter selection has been based onthe measurement of the radiation of the entire device. The new selection method based onthe signal’s Fast Fourier Transform (FFT) measurement has proved to be efficient. The EMIfilter is optimized separately for each line. The method described in this paper involving aCentral Processor Unit (CPU) module demonstrates that the proposed FFT-based selectionmethod is better than the radiation-based one. The radiation level in the frequency range 30MHz to 1 GHz is lower for approximate 2 – 6 dBμV/m.
Envisat Ocean Altimetry Performance Assessment and Cross-calibration
Authors: Faugere Yannice , Dorandeu Joël , Lefevre Fabien , Picot Nicolas , Femenias Pierre
Published: October 2008

Nearly three years of Envisat altimetric observations over ocean are available inGeophysical Data Record (GDR) products. The quality assessment of these data is routinelyperformed at the CLS Space Oceanography Division in the frame of the CNES Segment SolAltimétrie et Orbitographie (SSALTO) and ESA French Processing and Archiving Center(F-PAC) activities. This paper presents the main results in terms of Envisat data quality:verification of data availability and validity, monitoring of the most relevant altimeter(ocean1 retracking) and radiometer parameters, assessment of the Envisat altimeter systemperformances. This includes a cross-calibration analysis of Envisat data with Jason-1, ERS-2 and T/P. Envisat data show good general quality. A good orbit quality and a low level ofnoise allow Envisat to reach the high level of accuracy of other precise missions such as T/Pand Jason-1. Some issues raised in this paper, as the gravity induced orbit errors, will besolved in the next version of GDR products. Some others, as the Envisat Mean Sea Level inthe first year, still need further investigation.
Impact of Altimeter Data Processing on Sea Level Studies
Authors: Fernandes M. Joana , Barbosa Susana , Lázaro Clara
Published: October 2008

This study addresses the impact of satellite altimetry data processing on sea levelstudies at regional scale, with emphasis on the influence of various geophysical correctionsand satellite orbit on the structure of the derived interannual signal and sea level trend. Thework focuses on the analysis of TOPEX data for a period of over twelve years, for threeregions in the North Atlantic: Tropical (0o≤φ≤25o), Sub-Tropical (25o≤φ≤50o) and Sub-Arctic (50o≤φ≤65o). For this analysis corrected sea level anomalies with respect to a meansea surface model have been derived from the GDR-Ms provided by AVISO by applyingvarious state-of-the-art models for the geophysical corrections. Results show that sea leveltrend determined from TOPEX altimetry is dependent on the adopted models for the majorgeophysical corrections. The main effects come from the sea state bias (SSB), and from theapplication or not of the inverse barometer (IB) correction. After an appropriate modellingof the TOPEX A/B bias, the two analysed SSB models induce small variations in sea leveltrend, from 0.0 to 0.2 mm/yr, with a small latitude dependence. The difference in sea leveltrend determined by a non IB-corrected series and an IB-corrected one has a strong regionaldependence with large differences in the shape of the interannual signals and in the derivedlinear trends. The use of two different drift models for the TOPEX Microwave Radiometer(TMR) has a small but non negligible effect on the North Atlantic sea level trend of about0.1 mm/yr. The interannual signals of sea level time series derived with the NASA and theCNES orbits respectively, show a small departure in the middle of the series, which has noimpact on the derived sea level trend. These results strike the need for a continuousimprovement in the modelling of the various effects that influence the altimetermeasurement.
Performances Study of Interferometric Radar Altimeters: from the Instrument to the Global Mission Definition
Authors: Enjolras Vivien , Vincent Patrick , Souyris Jean-Claude , Rodriguez Ernesto , Phalippou Laurent , Cazenave Anny
Published: October 2008

The main limitations of standard nadir-looking radar altimeters have been knownfor long. They include the lack of coverage (intertrack distance of typically 150 km for theT/P / Jason tandem), and the spatial resolution (typically 2 km for T/P and Jason), expectedto be a limiting factor for the determination of mesoscale phenomena in deep ocean. In thiscontext, various solutions using off-nadir radar interferometry have been proposed byRodriguez and al to give an answer to oceanographic mission objectives. This paperaddresses the performances study of this new generation of instruments, and dedicatedmission. A first approach is based on the Wide-Swath Ocean Altimeter (WSOA) intended tobe implemented onboard Jason-2 in 2004 but now abandoned. Every error domain has beenchecked: the physics of the measurement, its geometry, the impact of the platform andexternal errors like the tropospheric and ionospheric delays. We have especially shown thestrong need to move to a sun-synchronous orbit and the non-negligible impact of propagation media errors in the swath, reaching a few centimetres in the worst case. Some changes in the parameters of the instrument have also been discussed to improve the overall error budget. The outcomes have led to the definition and the optimization of such an instrument and its dedicated mission.
Combined Wind Vector and Sea State Impact on Ocean Nadir-Viewing Ku- and C-Band Radar Cross-Sections
Authors: Tran Ngan , Chapron Bertrand
Published: October 2008

The authors report the first results in studying the polarization anisotropy of themicrowave backscatter from nadir observations provided by Jason-1 altimeter in both Ku-and C-band. A small but clear wind direction signal for wind speeds above 6 m/s is revealed.These azimuthal variations of radar cross-section increase with increasing wind speed up to14 m/s. The signatures then level off at higher winds. These results extend, for the first time,recent theoretical improved scattering approximation, and point some similarities betweenscattering and emission mechanisms at nadir. The observed directional effect can thus beinterpreted as a signature of the curvature anisotropy of wind-generated short-scale waves.Sensitivities to both wind speed and sea state are also reported in the present analysis.
AltiKa: a Ka-band Altimetry Payload and System for Operational Altimetry during the GMES Period
Authors: Vincent Patrick , Steunou Nathalie , Caubetq Eric , Phalippou Laurent , Rey Laurent , Thouvenot Eric , Verron Jacques
Published: October 2008

This paper describes the Ka-band altimetry payload and system that has beenstudied for several years by CNES, ALCATEL SPACE and some science laboratories.Altimetry is one of the major elements of the ocean observing system to be madesustainable through the GEOSS (Global Earth Observation System of Systems) and GMES(Global Monitoring of the Environment and Security) programs. A short review of somemission objectives to be fulfilled in terms of mesoscale oceanography in the frame of theGEOSS and GMES programs is performed. To answer the corresponding requirements, theapproach consisting in a constellation of nadir altimeter is discussed. A coupled Ka-bandaltimeter-radiometer payload is then described; technical items are detailed to explain howthis payload shall meet the science and operational requirements, and expectedperformances are displayed. The current status of the payload development and flightperspectives are given.
A First Comparison of Simultaneous Sea Level Measurements from Envisat, GFO, Jason-1, and TOPEX/Poseidon
Authors: Zhang Caiyun , Chen Ge
Published: October 2008

The multiple altimeter missions have not only advanced our knowledge of oceancirculation, ice sheet topography, and global climate, but also improved the accuracy ofaltimetric measurements by cross-calibration and validation. In this paper, one year’ssimultaneous maps of sea level anomaly (MSLA) data obtained from four altimeters,Envisat, Geosat Follow-On (GFO), Jason-1, and TOPEX/Poseidon (T/P), have beencompiled for a preliminary comparison. First, the discrepancy in global geographicaldistribution of each product relative to the merged MSLA field is analyzed and its signalretrieval capability is discussed. Second, the space/time variability of each discrepancy inthe Atlantic Ocean, Indian Ocean, Pacific Ocean, Northern Hemisphere, SouthernHemisphere, and global ocean is studied. Third, each discrepancy as a function of latitude,longitude, and merged MSLA is presented. The results show that Jason-1 is the best single-mission for mapping large scale sea level variation, while T/P in its new orbit presents thepoorest estimation of SLA due to the short period (from cycle 369 to 403) used to determinethe mean profile. A clear understanding of each product discrepancy is necessary for ameaningful combination or merging of multi-altimeter data, optimal product selection, aswell as for their assimilation into numerical models.
The Story of GANDER
Authors: Allen Tom
Published: October 2008

GANDER – for Global Altimeter Network Designed to Evaluate Risk – was anidea that was probably ahead of its time. Conceived at a time when ocean observingsatellites were sometimes 10 years in the planning stage, the concept of affordable fastersampling through the use of altimeter-carrying microsats was primarily advanced as a wayof detecting and tracking storms at sea on a daily basis. But, of course, a radar altimetermonitors changes in sea-level as well as surface wave height and wind speed. Here then is asystem which, flown with more precise missions such as JASON 2, could meet the needs ofocean modellers by providing the greater detail required for tracking mesoscale eddies,whilst servicing forecasting centres and units at sea with near real-time sea state information.A tsunami mode, instantly activated when an undersea earthquake is detected by the globalnetwork of seismic stations, could also be incorporated.
Preface of the Special Issue of I3S 2005 in Jülich (Germany)
Authors: Wagner Torsten , Schöning Michael
Published: October 2008

The “Third International Symposium on Sensor Science (I3S 2005)” was held at the Aachen University of Applied Sciences (AcUAS) from 18-21 July 2005 in Jülich, Germany.[...]
Study of Swift Heavy Ion Modified Conducting Polymer Composites for Application as Gas Sensor
Authors: Srivastava Alok , Singh Virendra , Dhand Chetna , Kaur Manindar , Singh Tejvir , Witte Karin , Scherer Ulrich  W.
Published: October 2008

A polyaniline-based conducting composite was prepared by oxidativepolymerisation of aniline in a polyvinylchloride (PVC) matrix. The coherent free standingthin films of the composite were prepared by a solution casting method. The polyvinylchloride-polyaniline composites exposed to 120 MeV ions of silicon with total ion fluenceranging from 1011 to 1013 ions/cm2, were observed to be more sensitive towards ammoniagas than the unirradiated composite. The response time of the irradiated composites wasobserved to be comparably shorter. We report for the first time the application of swiftheavy ion modified insulating polymer conducting polymer (IPCP) composites for sensingof ammonia gas.
Modular Analytical Multicomponent Analysis in Gas Sensor Aarrays
Authors: Chaiyboun Ali , Traute Rüdiger , Kiesewetter Olaf , Ahlers Simon , Müller Gerhard , Doll Theodor
Published: October 2008

A multi-sensor system is a chemical sensor system which quantitatively andqualitatively records gases with a combination of cross-sensitive gas sensor arrays andpattern recognition software. This paper addresses the issue of data analysis foridentification of gases in a gas sensor array. We introduce a software tool for gas sensorarray configuration and simulation. It concerns thereby about a modular software packagefor the acquisition of data of different sensors. A signal evaluation algorithm referred to asmatrix method was used specifically for the software tool. This matrix method computes thegas concentrations from the signals of a sensor array. The software tool was used for thesimulation of an array of five sensors to determine gas concentration of CH4, NH3, H2, COand C2H5OH. The results of the present simulated sensor array indicate that the softwaretool is capable of the following: (a) identify a gas independently of its concentration; (b)estimate the concentration of the gas, even if the system was not previously exposed to thisconcentration; (c) tell when a gas concentration exceeds a certain value. A gas sensor database was build for the configuration of the software. With the data base one can create,generate and manage scenarios and source files for the simulation. With the gas sensor database and the simulation software an on-line Web-based version was developed, with whichthe user can configure and simulate sensor arrays on-line.
Response Behaviour of a Hydrogen Sensor Based on IonicConducting Polymer-metal Interfaces Prepared by the ChemicalReduction Method
Authors: Sakthivel Mariappan , Weppner Werner
Published: October 2008

A solid-state amperometric hydrogen sensor based on a protonated Nafionmembrane and catalytic active electrode operating at room temperature was fabricated andtested. Ionic conducting polymer-metal electrode interfaces were prepared chemically byusing the impregnation-reduction method. The polymer membrane was impregnated withtetra-ammine platinum chloride hydrate and the metal ions were subsequently reduced byusing either sodium tetrahydroborate or potassium tetrahydroborate. The hydrogen sensingcharacteristics with air as reference gas is reported. The sensors were capable of detectinghydrogen concentrations from 10 ppm to 10% in nitrogen. The response time was in therange of 10-30 s and a stable linear current output was observed. The thin Pt films werecharacterized by XRD, Infrared Spectroscopy, Optical Microscopy, Atomic ForceMicroscopy, Scanning Electron Microscopy and EDAX.
Workflow for High Throughput Screening of Gas Sensing Materials
Authors: Koplin Tobias  J. , Siemons Maike , Océn-Valéntin César , Sanders Daniel , Simon Ulrich
Published: October 2008

The workflow of a high throughput screening setup for the rapid identification ofnew and improved sensor materials is presented. The polyol method was applied to preparenanoparticular metal oxides as base materials, which were functionalised by surface doping.Using multi-electrode substrates and high throughput impedance spectroscopy (HT-IS) awide range of materials could be screened in a short time. Applying HT-IS in search of newselective gas sensing materials a NO2-tolerant NO sensing material with reducedsensitivities towards other test gases was identified based on iridium doped zinc oxide.Analogous behaviour was observed for iridium doped indium oxide.
Detection of Hydrogen Peroxide (H2O2) at ExposedTemperatures for Industrial Processes
Authors: Näther Niko , Juárez Leon  M. , Emmerich Rüdiger , Berger Jörg , Friedrich Peter , Schöning Michael J.
Published: October 2008

An H2O2 sensor for the application in industrial sterilisation processes has beendeveloped. Therefore, automated sterilisation equipment at laboratory scale has beenconstructed using parts from industrial sterilisation facilities. In addition, a software tool hasbeen developed for the control of the sterilisation equipment at laboratory scale. Firstmeasurements with the developed sensor set-up as part of the sterilisation equipment havebeen performed and the sensor has been physically characterised by optical microscopy andSEM.