bluuebunny/crossref_metadata_2025 huggingface dataset:
Flow Injection Technique for Biochemical Analysis with Chemiluminescence Detection in Acidic Media
Authors: Chen Jing , Fang Yanjun
Published: October 2008

A review with 90 references is presented to show the development of acidic chemiluminescence methods for biochemical analysis by use of flow injection technique in the last 10 years. A brief discussion of both the chemiluminescence and flow injection technique is given. The proposed methods for biochemical analysis are described and compared according to the used chemiluminescence system.
Step Prediction During Perturbed Standing Using Center Of Pressure Measurements
Authors: Tortolero Xavier , Masani Kei , Popovic Milos R.
Published: October 2008

The development of a sensor that can measure balance during quiet standing and predict stepping response in the event of perturbation has many clinically relevant applica- tions, including closed-loop control of a neuroprothesis for standing. This study investigated the feasibility of an algorithm that can predict in real-time when an able-bodied individual who is quietly standing will have to make a step to compensate for an external perturbation. Anterior and posterior perturbations were performed on 16 able-bodied subjects using a pul- ley system with a dropped weight. A linear relationship was found between the peak center of pressure (COP) velocity and the peak COP displacement caused by the perturbation. This result suggests that one can predict when a person will have to make a step based on COP velocity measurements alone. Another important feature of this finding is that the peak COP velocity occurs considerably before the peak COP displacement. As a result, one can predict if a subject will have to make a step in response to a perturbation sufficiently ahead of the time when the subject is actually forced to make the step. The proposed instability detection algorithm will be implemented in a sensor system using insole sheets in shoes with minitur- ized pressure sensors by which the COPv can be continuously measured. The sensor system will be integrated in a closed-loop feedback system with a neuroprosthesis for standing in the near future.
Design and Development of a Flexible Strain Sensor for Textile Structures Based on a Conductive Polymer Composite
Authors: Cochrane Cédric , Koncar Vladan , Lewandowski Maryline , Dufour Claude
Published: October 2008

The aim of this work is to develop a smart flexible sensor adapted to textile structures, able to measure their strain deformations. The sensors are “smart” because of their capacity to adapt to the specific mechanical properties of textile structures that are lightweight, highly flexible, stretchable, elastic, etc. Because of these properties, textile structures are continuously in movement and easily deformed, even under very low stresses. It is therefore important that the integration of a sensor does not modify their general behavior. The material used for the sensor is based on a thermoplastic elastomer (Evoprene)/carbon black nanoparticle composite, and presents general mechanical properties strongly compatible with the textile substrate. Two preparation techniques are investigated: the conventional melt-mixing process, and the solvent process which is found to be more adapted for this particular application. The preparation procedure is fully described, namely the optimization of the process in terms of filler concentration in which the percolation theory aspects have to be considered. The sensor is then integrated on a thin, lightweight Nylon fabric, and the electromechanical characterization is performed to demonstrate the adaptability and the correct functioning of the sensor as a strain gauge on the fabric. A normalized relative resistance is defined in order to characterize the electrical response of the sensor. Finally, the influence of environmental factors, such as temperature and atmospheric humidity, on the sensor performance is investigated. The results show that the sensor’s electrical resistance is particularly affected by humidity. This behavior is discussed in terms of the sensitivity of the carbon black filler particles to the presence of water.
Fabrication and Characterization of PZT Thick Films for Sensing and Actuation
Authors: Jang Ling-Sheng , Kuo Kuo-Ching
Published: October 2008

Lead Zirconate Titanate oxide (PZT) thick films with thicknesses of up to 10 μmwere developed using a modified sol-gel technique. Usually, the film thickness is less than1 μm by conventional sol-gel processing, while the electrical charge accumulation whichreveals the direct effect of piezoelectricity is proportional to the film thickness and thereforerestricted. Two approaches were adopted to conventional sol-gel processing – precursorconcentration modulation and rapid thermal annealing. A 10 μm thick film was successfullyfabricated by coating 16 times via this technique. The thickness of each coating layer wasabout 0.6 μm and the morphology of the film was dense with a crack-free area as large as 16mm2. In addition, the structure, surface morphology and physical properties werecharacterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomicforce microscopy (AFM) and electrical performance. The dielectric constant and hysteresisloops were measured as electric characteristics. This study investigates the actuation andsensing performance of the vibrating structures with the piezoelectric thick film. Theactuation tests demonstrated that a 4 mm x 4 mm x 6.5 μm PZT film drove a 40 mm x 7 mmx 0.5 mm silicon beam as an actuator. Additionally, it generated an electrical signal of 60mVpp as a sensor, while vibration was input by a shaker. The frequencies of the first twomodes of the beam were compared with the theoretical values obtained by Euler-Bernoullibeam theory. The linearity of the actuation and sensing tests were also examined.
Guided-Wave Optical Biosensors
Authors: Passaro Vittorio M. N. , Dell’Olio Francesco , Casamassima Biagio , De Leonardis Francesco
Published: October 2008

Guided-wave optical biosensors are reviewed in this paper. Advantages related to optical technologies are presented and integrated architectures are investigated in detail. Main classes of bio receptors and the most attractive optical transduction mechanisms are discussed. The possibility to use Mach-Zehnder and Young interferometers, microdisk and microring resonators, surface plasmon resonance, hollow and antiresonant waveguides, and Bragg gratings to realize very sensitive and selective, ultra-compact and fast biosensors is discussed. Finally, CMOS-compatible technologies are proved to be the most attractive for fabrication of guided-wave photonic biosensors.
Simulated Effects of Soil Temperature and Salinity on Capacitance Sensor Measurements
Authors: Schwank Mike , Green Timothy  R.
Published: October 2008

Dielectric measurement techniques are used widely for estimation of water contentin environmental media. However, factors such as temperature and salinity affecting thereadings require further quantitative investigation and explanation. Theoretical sensitivities ofcapacitance sensors to liquid salinity and temperature of porous media were derived andcomputed using a revised electrical circuit analogue model in conjunction with a dielectricmixing model and a finite element model of Maxwell’s equation to compute electrical fielddistributions. The mixing model estimates the bulk effective complex permittivities of solid-water-air media. The real part of the permittivity values were used in electric field simulations,from which different components of capacitance were calculated via numerical integration forinput to the electrical circuit analogue. Circuit resistances representing the dielectric losses werecalculated from the complex permittivity of the bulk soil and from the modeled fields. Resonantfrequencies from the circuit analogue were used to update frequency-dependent variables in aniterative manner. Simulated resonant frequencies of the capacitance sensor display sensitivitiesto both temperature and salinity. The gradients in normalized frequency with temperatureranged from negative to positive values as salinity increased from 0 to 10 g L-1. The modeldevelopment and analyses improved our understanding of processes affecting the temperatureand salinity sensitivities of capacitance sensors in general. This study provides a foundation forfurther work on inference of soil water content under field conditions.
A Sensitive Chemiluminescence Method for Determination of Hydroquinone and Catechol
Authors: Zhao Lijun , Lv Baoqiang , Yuan Hongyan , Zhou Zaide , Xiao Dan
Published: October 2008

A novel flow-injection chemiluminescence(CL)method has been developedfor the determination of hydroquinone (HQ) and catechol (CT), based on their inhibition ofthe chemiluminescence reaction of luminol–KMnO4–β-cyclodextrin (β-CD). It was foundthat β-cyclodextrin could effectively enhance the chemiluminescence produced from thereaction of luminol with KMnO4 in basic media. The proposed method is simple, rapid,convenient and sensitive, has a linear range of 1–20 ng/mL for catechol with a detectionlimit of 0.4 ng/mL, and 1–10 ng/mL for hydroquinone with a detection limit of 0.1 ng/mL,respectively. The possible mechanism of the CL reaction is also discussed
Biosensors and Bio-Bar Code Assays Based on Biofunctionalized Magnetic Microbeads
Authors: Jaffrezic-Renault Nicole , Martelet Claude , Chevolot Yann , Cloarec Jean-Pierre
Published: October 2008

This review paper reports the applications of magnetic microbeads in biosensors and bio-bar code assays. Affinity biosensors are presented through different types of transducing systems: electrochemical, piezo electric or magnetic ones, applied to immunodetection and genodetection. Enzymatic biosensors are based on biofunctionalization through magnetic microbeads of a transducer, more often amperometric, potentiometric or conductimetric. The bio-bar code assays relie on a sandwich structure based on specific biological interaction of a magnetic microbead and a nanoparticle with a defined biological molecule. The magnetic particle allows the separation of the reacted target molecules from unreacted ones. The nanoparticles aim at the amplification and the detection of the target molecule. The bio-bar code assays allow the detection at very low concentration of biological molecules, similar to PCR sensitivity.
Electrochemical Oxidation and Determination of Oxalic Acid at an Exfoliated Graphite-Polystyrene Composite Electrode
Authors: Manea Florica , Radovan Ciprian , Corb Ioana , Pop Aniela , Burtica Georgeta , Malchev Plamen , Picken Stephen , Schoonman Joop
Published: October 2008

An exfoliated graphite-polystyrene composite electrode was evaluated as analternative electrode in the oxidation and the determination of oxalic acid in 0.1 M Na2SO4supporting electrolyte. Using CV, LSV, CA procedures, linear dependences I vs. C wereobtained in the concentrations range of oxalic acid between 0.5 to 3 mM, with LOD =0.05mM, and recovery degree of 98%, without need of surface renewing between successiveruns. The accuracy of the methods was evaluated as excellent comparing the detection resultswith that obtained using conventional KMnO4 titration method. In addition, the apparentdiffusion coefficient of oxalic acid D was found to be around 2.89 · 10-8 cm2·s-1 by CA andCV.
Distributed Particle Swarm Optimization and Simulated Annealing for Energy-efficient Coverage in Wireless Sensor Networks
Authors: Wang Xue , Ma Jun-Jie , Wang Sheng , Bi Dao-Wei
Published: October 2008

The limited energy supply of wireless sensor networks poses a great challenge for the deployment of wireless sensor nodes. In this paper, we focus on energy-efficient coverage with distributed particle swarm optimization and simulated annealing. First, the energy-efficient coverage problem is formulated with sensing coverage and energy consumption models. We consider the network composed of stationary and mobile nodes. Second, coverage and energy metrics are presented to evaluate the coverage rate and energy consumption of a wireless sensor network, where a grid exclusion algorithm extracts the coverage state and Dijkstra’s algorithm calculates the lowest cost path for communication. Then, a hybrid algorithm optimizes the energy consumption, in which particle swarm optimization and simulated annealing are combined to find the optimal deployment solution in a distributed manner. Simulated annealing is performed on multiple wireless sensor nodes, results of which are employed to correct the local and global best solution of particle swarm optimization. Simulations of wireless sensor node deployment verify that coverage performance can be guaranteed, energy consumption of communication is conserved after deployment optimization and the optimization performance is boosted by the distributed algorithm. Moreover, it is demonstrated that energy efficiency of wireless sensor networks is enhanced by the proposed optimization algorithm in target tracking applications.
Sensors Makes Sense
Authors: Burkhalter Matthias
Published: October 2008

During my varied professional experience in different industries I have previously edited a number of trade magazines and newsletters.[...]
Improvement of Flame-made ZnO Nanoparticulate Thick Film Morphology for Ethanol Sensing
Authors: Liewhiran Chaikarn , Phanichphant Sukon
Published: October 2008

ZnO nanoparticles were produced by flame spray pyrolysis using zinc naphthenate as a precursor dissolved in toluene/acetonitrile (80/20 vol%). The particles properties were analyzed by XRD, BET. The ZnO particle size and morphology was observed by SEM and HR-TEM revealing spheroidal, hexagonal, and rod-like morphologies. The crystallite sizes of ZnO spheroidal and hexagonal particles ranged from 10-20 nm. ZnO nanorods were ranged from 10-20 nm in width and 20-50 nm in length. Sensing films were produced by mixing the nanoparticles into an organic paste composed of terpineol and ethyl cellulose as a vehicle binder. The paste was doctor-bladed onto Al2O3 substrates interdigitated with Au electrodes. The morphology of the sensing films was analyzed by optical microscopy and SEM analysis. Cracking of the sensing films during annealing process was improved by varying the heating conditions. The gas sensing of ethanol (25-250 ppm) was studied at 400 °C in dry air containing SiC as the fluidized particles. The oxidation of ethanol on the surface of the semiconductor was confirmed by mass spectroscopy (MS). The effect of micro-cracks was quantitatively accounted for as a provider of extra exposed edges. The sensitivity decreased notably with increasing crack of sensing films. It can be observed that crack widths were reduced with decreasing heating rates. Crack-free of thick (5 μm) ZnO films evidently showed higher sensor signal and faster response times (within seconds) than cracked sensor. The sensor signal increased and the response time decreased with increasing ethanol concentration.
Behavior of Random Hole Optical Fibers under Gamma Ray Irradiation and Its Potential Use in Radiation Sensing Applications
Authors: Alfeeli Bassam , Pickrell Gary , Garland Marc A. , Wang Anbo
Published: October 2008

Effects of radiation on sensing and data transmission components are of greatinterest in many applications including homeland security, nuclear power generation, andmilitary. A new type of microstructured optical fiber (MOF) called the random hole opticalfiber (RHOF) has been recently developed. The RHOFs can be made in many differentforms by varying the core size and the size and extent of porosity in the cladding region.The fibers used in this study possessed an outer diameter of 110 μm and a core ofapproximately 20 μm. The fiber structure contains thousands of air holes surrounding thecore with sizes ranging from less than 100 nm to a few μm. We present the first study ofthe behavior of RHOF under gamma irradiation. We also propose, for the first time to ourknowledge, an ionizing radiation sensor system based on scintillation light from ascintillator phosphor embedded within a holey optical fiber structure. The RHOF radiationresponse was compared to normal single mode and multimode commercial fibers(germanium doped core, pure silica cladding) and to those of radiation resistant fibers (puresilica core with fluorine doped cladding fibers). The comparison was done by measuringradiation-induced absorption (RIA) in all fiber samples at the 1550 nm wavelength window(1545 ± 25 nm). The study was carried out under a high-intensity gamma ray field from a 60Co source (with an exposure rate of 4x104 rad/hr) at an Oak Ridge National Laboratory gamma ray irradiation facility. Linear behavior, at dose values less than 106 rad, was observed in all fiber samples except in the pure silica core fluorine doped cladding fiber which showed RIA saturation at 0.01 dB. RHOF samples demonstrated low RIA (0.02 and 0.005 dB) compared to standard germanium doped core pure silica cladding (SMF and MMF) fibers. Results also showed the possibility of post-fabrication treatment to improve the radiation resistance of the RHOF fibers.
Simulation of Optical Microfiber Loop Resonators for Ambient Refractive Index Sensing
Authors: Shi Lei , Xu Yonghao , Tan Wei , Chen Xianfeng
Published: October 2008

Based on theoretical modeling and optimization, we exploit the application ofoptical microfiber loop resonators in ambient refractive index sensing. We set up a reliabletheoretical model and optimize the structural parameters of microfiber loop resonatorsincluding the radius of the microrfiber, the radius of the loop and the length of the couplingregion for higher sensitivity, wider dynamic measurement range, and lower detection limit.To show the convincible and realizable sensing ability we perform the simulation ofsensing an extreme small variation of ambient refractive index by employing a set ofexperimental data as the parameters in the expression of intensity transmission coefficient,and the detection limit reaches to a variation of ambient refractive index of 10-5 refractiveindex unit (RIU). This has superiority over the existing evanescent field-basedsubwavelength-diameter optical fiber refractive index sensor.
An Experimental Study on the Fabrication of Glass-based Acceleration Sensor Body Using Micro Powder Blasting Method
Authors: Park Dong-Sam , Yun Dae-Jin , Cho Myeong-Woo , Shin Bong-Cheol
Published: October 2008

This study investigated the feasibility of the micro powder blasting technique for the micro fabrication of sensor structures using the Pyrex glass to replace the existing silicon-based acceleration sensor fabrication processes. As the preliminary experiments, the effects of the blasting pressure, the mass flow rate of abrasive and the number of nozzle scanning times on erosion depth of the Pyrex and the soda lime glasses were examined. From the experimental results, optimal blasting conditions were selected for the Pyrex glass machining. The dimensions of the designed glass sensor was 1.7×1.7×0.6mm for the vibrating mass, and 2.9×0.7×0.2mm for the cantilever beam. The machining results showed that the dimensional errors of the machined glass sensor ranged from 3 μm in minimum to 20 μm in maximum. These results imply that the micro powder blasting method can be applied for the micromachining of glass-based acceleration sensors to replace the exiting method.
Preparation of Silver Nanoparticle and Its Application to the Determination of ct-DNA
Authors: Liu Chunhua , Yang Xiupei , Yuan Hongyan , Zhou Zaide , Xiao Dan
Published: October 2008

A new method to prepare silver nanoparticles was reported in this paper, whichbased on aqueous-gaseous phase reaction of silver nitrate solution and ammonia gas. Theproposed method is effective, rapid, and convenient. Transmission electron microscope(TEM) and X-ray diffraction (XRD) were used to characterize the structure of the particles,respectively. It was found that the average diameter of the particles was about 10 nm and theshape was spherical. And the strong fluorescence signal of the silver nanoparticles solutioncan be quenched after the adding of the calf thymus DNA (ct-DNA) solution. Thequenched fluorescence intensity was linear with the concentration of ct-DNA in the range of0.5 to 5.0 × 104 ng mL-1 with a detection limit of 0.3 ng mL-1.
Horseradish Peroxidase (HRP) Immobilized Poly(aniline-co-m-aminophenol) Film Electrodes–fabrication and Evaluation as Hydrogen Peroxide Sensor
Authors: Seo Kang-Deuk , Lee Kwang-Pill , Gopalan Anantha  Iyengar , Chung Sang  J. , Lim Yong  Taik , Choi Seong-Ho
Published: October 2008

Enzyme modified electrodes were fabricated with poly(aniline-co-m-aminophenol). Electrochemical polymerization of aniline and m-aminophenol wasperformed to get the film of copolymer on the surface of gold electrode. Modifiedelectrodes were fabricated by two methods, physical entrapment and covalent cross-linking.In one of the method, gold nanoparticles were loaded into the copolymer film andhorseradish peroxidase (HRP) was immobilized into the Au nanoparticle loaded copolymerfilm through physical entrapment. In the other method, the amino and -OH groups in thecopolymer are utilized to form covalent functionalization with HRP via glutaric dialdehydeas cross-linker/mediator. The conducting copolymer/enzyme modified electrodes preparedby physical entrapment/covalent functionalization of enzyme were tested forelectrocatalytic activities towards sensing of H2O2. Amperometric results indicate thatenzyme modified electrode via physical entrapment possesses better electrocatalyticperformance over covalent functionalized enzyme electrode.
Optimized Self Organized Sensor Networks
Authors: Park Sungyun , Shin Kwangcheol , Abraham Ajith , Han SangYong
Published: October 2008

Wireless sensor networks are composed of a huge number of sensor nodes, which have limited resources - energy, memory and computation power. Energies are directly related to the lifetime of sensor network. If sensor nodes can be grouped to clusters, cluster member sensor nodes only need to communicate with cluster center (head) and this leads to energy conservation of the member sensors. So, how to compose clusters with minimal number of cluster heads, while including each node in a cluster is an important research issue. We propose a new advanced optimization algorithm for sensor network clustering. Using the proposed optimization algorithm, redundant cluster heads are eliminated, and unnecessarily overlapped clusters are merged. Optimization algorithm can be used as a clustering algorithm by itself and also manage the dynamic changes like node addition or die-out, while the network is even on the working state. We tested the proposed method as a clustering algorithm and compared it with two other recent sensor network clustering algorithms, Algorithm for Cluster Establishment (ACE) and Self Organizing Sensor network algorithm (SOS). The experiments results not only illustrate that the proposed algorithm could result in clusters with smaller number of cluster heads than others with any density of sensor networks, but also that the performance is more stable, which is also verified through repeated experiments.
Multi-instrumental Investigation of Affecting of Early Somatic Embryos of Spruce by Cadmium(II) and Lead(II) Ions
Authors: Supalkova Veronika , Petrek Jiri , Baloun Jiri , Adam Vojtech , Bartusek Karel , Trnkova Libuse , Beklova Miroslava , Diopan Vaclav , Havel Ladislav , Kizek René
Published: October 2008

The main aim of this work was to use multi-instrumental analytical apparatus toinvestigate the effects of treatment with cadmium(II) and/or lead(II) ions (50, 250 and 500μM) for twelve days on early somatic spruce embryos (ESEs). Primarily we used imageanalysis for estimation of growth and a fluorimetric sensor for enzymatic detection ofviability of the treated ESEs. It follows from the obtained results that Cd caused highertoxicity to ESEs than Pb. Besides this fundamental finding, we observed that ESEs grewand developed better in the presence of 500 μM of the metal ions than in the presence of250 μM. Based on the results obtained using nuclear magnetic resonance this phenomenonwas related to an increase of the area of ESE clusters by intensive uptake of water from thecultivation medium, due to dilution of the heavy metal concentration inside the cluster. Inaddition we studied the glutathione content in treated ESEs by the adsorptive transferstripping technique coupled with the differential pulse voltammetry Brdicka reaction. GSHcontents increased up to 148 ng/mg (clone 2/32) and 158 ng/mg (clone PE 14) after twelve day long treatment with Cd-EDTA ions. The GSH content was about 150 and 160 % higher in comparison with the ESEs treated with Pb-EDTA ions, respectively. The difference between GSH contents determined in ESEs treated with Pb-EDTA and Cd-EDTA ions correlates with the higher toxicity of cadmium(II) ions.
Stability, Nonlinearity and Reliability of Electrostatically Actuated MEMS Devices
Authors: Zhang Wen-Ming , Meng Guang , Chen Di
Published: October 2008

Electrostatic micro-electro-mechanical system (MEMS) is a special branch with a wide range of applications in sensing and actuating devices in MEMS. This paper provides a survey and analysis of the electrostatic force of importance in MEMS, its physical model, scaling effect, stability, nonlinearity and reliability in detail. It is necessary to understand the effects of electrostatic forces in MEMS and then many phenomena of practical importance, such as pull-in instability and the effects of effective stiffness, dielectric charging, stress gradient, temperature on the pull-in voltage, nonlinear dynamic effects and reliability due to electrostatic forces occurred in MEMS can be explained scientifically, and consequently the great potential of MEMS technology could be explored effectively and utilized optimally. A simplified parallel-plate capacitor model is proposed to investigate the resonance response, inherent nonlinearity, stiffness softened effect and coupled nonlinear effect of the typical electrostatically actuated MEMS devices. Many failure modes and mechanisms and various methods and techniques, including materials selection, reasonable design and extending the controllable travel range used to analyze and reduce the failures are discussed in the electrostatically actuated MEMS devices. Numerical simulations and discussions indicate that the effects of instability, nonlinear characteristics and reliability subjected to electrostatic forces cannot be ignored and are in need of further investigation.
Recent Development in Optical Fiber Biosensors
Authors: Bosch María Espinosa , Sánchez Antonio Jesús Ruiz , Rojas Fuensanta Sánchez , Ojeda Catalina Bosch
Published: October 2008

Remarkable developments can be seen in the field of optical fibre biosensors in the last decade. More sensors for specific analytes have been reported, novel sensing chemistries or transduction principles have been introduced, and applications in various analytical fields have been realised. This review consists of papers mainly reported in the last decade and presents about applications of optical fiber biosensors. Discussions on the trends in optical fiber biosensor applications in real samples are enumerated.
Comparison of Three Operative Models for Estimating the Surface Water Deficit Using ASTER Reflective and Thermal Data
Authors: García Mónica , Villagarcía Luis , Contreras Sergio , Domingo Francisco , Puigdefábregas Juan
Published: October 2008

Three operative models with minimum input data requirements for estimatingthe partition of available surface energy into sensible and latent heat flux using ASTERdata have been evaluated in a semiarid area in SE Spain. The non-evaporative fraction(NEF) is proposed as an indicator of the surface water deficit. The best results wereachieved with NEF estimated using the “Simplified relationship” for unstable conditions(NEFSeguin) and with the S-SEBI (Simplified Surface Energy Balance Index) modelcorrected for atmospheric conditions (NEFS-SEBIt,) which both produced equivalent results.However, results with a third model, NEFCarlson, that estimates the exchange coefficient forsensible heat transfer from NDVI, were unrealistic for sites with scarce vegetation cover.These results are very promising for an operative monitoring of the surface water deficit,as validation with field data shows reasonable errors, within those reported in the literature(RMSE were 0.18 and 0.11 for the NEF, and 29.12 Wm-2 and 25.97 Wm-2 for sensible heatflux, with the Seguin and S-SEBIt models, respectively).
Can Satellite-derived Chlorophyll Imagery Be Used to Trace Surface Dynamics in Coastal Zone? A Case Study in the Northwestern Mediterranean Sea
Authors: Forget Philippe , André Gael
Published: October 2008

A comparison of chlorophyll data from SeaWiFS imagery and modeling results from a 3D hydrodynamical model was performed over the northwestern Mediterranean for the entire year of 2001. The study aims at investigating the information content brought by satellite-derived chlorophyll concentration ([Chl]) maps concerning surface dynamics in coastal zone. The study is mainly focused on the Gulf of Lions (GoL) and its outer region, which are mainly influenced by the Rhône River, local winds and the Northern Current (NC) flowing from the East along the continental slope. The physical hydrodynamical model was continuously run and 40 SeaWiFS images, presenting a significant coverage of the studied area, were selected. The comparison between [Chl] and sea surface salinity (SSS) fields on a pixel basis showed no definite correlation trends. Three reasons are given in discussion for that result. However, the comparison emphasized areas close to the coasts which were under the influence of different inputs not considered in the model and also of upwellings. A qualitative analysis of the data performed out of these regions exhibited significant similarities between [Chl] and SSS features. The signature of the Rhône ROFI (Region of Fresh Water Influence) and, in some cases, of the NC, was evidenced on [Chl] maps. We found that the intensity of this signature is seasonally modulated, e.g., it is low in open sea during the summer, oligotrophic, season. In addition, the signature of the Rhône ROFI in the western part of the GoL can be only partial due to local chlorophyll deficits. We conclude that, for the regional case studied, chlorophyll imagery can be used as a tracer of surface dynamics through surface salinity but with limitations, especially near the coasts.
Nonlinear Bayesian Algorithms for Gas Plume Detection and Estimation from Hyper-spectral Thermal Image Data
Authors: Heasler Patrick , Posse Christian , Hylden Jeff , Anderson Kevin
Published: October 2008

This paper presents a nonlinear Bayesian regression algorithm for detecting and estimating gas plume content from hyper-spectral data. Remote sensing data, by its very nature, is collected under less controlled conditions than laboratory data. As a result, the physics-based model that is used to describe the relationship between the observed remote- sensing spectra, and the terrestrial (or atmospheric) parameters that are estimated is typically littered with many unknown ”nuisance” parameters. Bayesian methods are well-suited for this context as they automatically incorporate the uncertainties associated with all nuisance parameters into the error estimates of the parameters of interest. The nonlinear Bayesian re- gression methodology is illustrated on simulated data from a three-layer model for longwave infrared (LWIR) measurements from a passive instrument. The generated LWIR scenes con- tain plumes of varying intensities, and this allows estimation uncertainty and probability of detection to be quantified. The results show that this approach should permit more accurate estimation as well as a more reasonable description of estimate uncertainty. Specifically, the methodology produces a standard error that is more realistic than that produced by matched filter estimation.
Detection of the Deformation of an Intelligent Textile in a Specific Point
Authors: Alsina Maria , Escudero Francesc , Margalef Jordi , Cambra Vicente , Gisbert José
Published: October 2008

An intelligent textile is a textile structure that measures and reacts in front of external agents or stimulus with or without integrated electronic equipment. . The finality of the present textile is to take one more step towards intelligent textile, considering the integration of electronics and textile needs, to be industrially viable and to keep up the necessary competitiveness, raising the final price as little as possible. The finality of these experiments is to develop a textile that varies in conductivity and resistance in relation to the elongation of the textile, detecting changes caused by the alteration of a piece of clothing, from the pressure of a finger on the material, for example. One of the most important characteristics of textile is the capacity of reproducing measures, of varying the response in different tests. Two lines of research were opened: the study of the most adequate structure to achieve a response that can be reproduced and the study of the best way of taking measures without altering the behavior of the textile.
Electroanalysis of Plant Thiols
Authors: Supalkova Veronika , Huska Dalibor , Diopan Vaclav , Hanustiak Pavel , Zitka Ondrej , Stejskal Karel , Baloun Jiri , Pikula Jiri , Havel Ladislav , Zehnalek Josef , Adam Vojtech , Trnkova Libuse , Beklova Miroslava , Kizek Rene
Published: October 2008

Due to unique physico-chemical properties of –SH moiety thiols comprise widegroup of biologically important compounds. A review devoted to biological functions ofglutathione and phytochelatins with literature survey of methods used to analysis of thesecompounds and their interactions with cadmium(II) ions and Murashige-Skoog medium ispresented. For these purposes electrochemical techniques are used. Moreover, we revealedthe effect of three different cadmium concentrations (0, 10 and 100 μM) on cadmiumuptake and thiols content in maize plants during 192 hours long experiments usingdifferential pulse anodic stripping voltammetry to detect cadmium(II) ions and highperformance liquid chromatography with electrochemical detection to determineglutathione. Cadmium concentration determined in tissues of the plants cultivated innutrient solution containing 10 μM Cd was very low up to 96 hours long exposition andthen the concentration of Cd markedly increased. On the contrary, the addition of 100 μMCd caused an immediate sharp increase in all maize plant parts to 96 hours Cd expositionbut subsequently the Cd concentration increased more slowly. A high performance liquidchromatography with electrochemical detection was used for glutathione determination intreated maize plants after 96 and 192 hours of treatment. The highest total content of glutathione per one plant was 6 μg (96 h, 10 μM Cd) in comparison with non-treated plant (control) where glutathione content was 1.5 μg. It can be concluded that electrochemical techniques have proved to be useful to analyse plant thiols.
Time-varying Brain Potentials and Interhemispheric Coherences of Anterior and Posterior Regions during Repetitive Unimanual Finger Movements
Authors: Meng Ling-Fu , Lu Chiu-Ping , Chan Hsiao-Lung
Published: October 2008

Previous brain electrophysiological research has studied the interregionalconnectivity during the tapping task and found that inter-hemispheric alpha coherence wasmore significant under bimanual task conditions than that under unilateral conditions, butthe interregional connectivity situation in the unilateral tapping condition was not exploredclearly. We have designed a unilateral repetitive finger-tapping task to delineate the anteriorand posterior cortex contributions to unilateral finger movement. Sixteen right handedcollege students participated in this study. Event related potentials (ERPs) and the strengthof event related coherence (ERCoh) were analyzed to examine the antero-posterodominance of cortical activity in the phase of early visual process (75-120ms), pre-execution(175-260ms), execution (310-420ms) and post-execution (420-620ms). Results showed thatthe occipital (Oz, O1 and O2), frontal (Fz, F3, and F4), fronto-central (Fz, Cz, F3 and C3),and parietal regions were the most pronounced in the early visual, pre-execution, execution,and post-execution phases, respectively. Moreover, among four inter-hemispheric pairs onlythe Coh (C3 and C4) was significantly correlated to reaction time (RT) of tapping in theexecution phase. In conclusion, the aforementioned variability of electrophysiological data(ERPs and coherence) and the change of antero-postero regional dominance with timereflect the relative importance of different mechanisms in different phases. The mechanismsof visual processing, motor planning, motor execution and feedback reward wereoperational, respectively.
A Coupled Remote Sensing and Simplified Surface Energy Balance Approach to Estimate Actual Evapotranspiration from Irrigated Fields
Authors: Senay Gabriel B. , Budde Michael , Verdin James P. , Melesse Assefa M.
Published: October 2008

Accurate crop performance monitoring and production estimation are critical fortimely assessment of the food balance of several countries in the world. Since 2001, theFamine Early Warning Systems Network (FEWS NET) has been monitoring cropperformance and relative production using satellite-derived data and simulation models inAfrica, Central America, and Afghanistan where ground-based monitoring is limitedbecause of a scarcity of weather stations. The commonly used crop monitoring models arebased on a crop water-balance algorithm with inputs from satellite-derived rainfallestimates. These models are useful to monitor rainfed agriculture, but they are ineffectivefor irrigated areas. This study focused on Afghanistan, where over 80 percent ofagricultural production comes from irrigated lands. We developed and implemented aSimplified Surface Energy Balance (SSEB) model to monitor and assess the performanceof irrigated agriculture in Afghanistan using a combination of 1-km thermal data and 250-m Normalized Difference Vegetation Index (NDVI) data, both from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. We estimated seasonal actual evapotranspiration (ETa) over a period of six years (2000-2005) for two major irrigated river basins in Afghanistan, the Kabul and the Helmand, by analyzing up to 19 cloud-free thermal and NDVI images from each year. These seasonal ETa estimates were used as relative indicators of year-to-year production magnitude differences. The temporal water- use pattern of the two irrigated basins was indicative of the cropping patterns specific to each region. Our results were comparable to field reports and to estimates based on watershed-wide crop water-balance model results. For example, both methods found that the 2003 seasonal ETa was the highest of all six years. The method also captured water management scenarios where a unique year-to-year variability was identified in addition to water-use differences between upstream and downstream basins. A major advantage of the energy-balance approach is that it can be used to quantify spatial extent of irrigated fields and their water-use dynamics without reference to source of water as opposed to a water- balance model which requires knowledge of both the magnitude and temporal distribution of rainfall and irrigation applied to fields.
Distributed Peer-to-Peer Target Tracking in Wireless Sensor Networks
Authors: Wang Xue , Wang Sheng , Bi Dao-Wei , Ma Jun-Jie
Published: October 2008

Target tracking is usually a challenging application for wireless sensor networks(WSNs) because it is always computation-intensive and requires real-time processing. Thispaper proposes a practical target tracking system based on the auto regressive movingaverage (ARMA) model in a distributed peer-to-peer (P2P) signal processing framework.In the proposed framework, wireless sensor nodes act as peers that perform target detection,feature extraction, classification and tracking, whereas target localization requires thecollaboration between wireless sensor nodes for improving the accuracy and robustness.For carrying out target tracking under the constraints imposed by the limited capabilities ofthe wireless sensor nodes, some practically feasible algorithms, such as the ARMA modeland the 2-D integer lifting wavelet transform, are adopted in single wireless sensor nodesdue to their outstanding performance and light computational burden. Furthermore, aprogressive multi-view localization algorithm is proposed in distributed P2P signalprocessing framework considering the tradeoff between the accuracy and energyconsumption. Finally, a real world target tracking experiment is illustrated. Results fromexperimental implementations have demonstrated that the proposed target tracking systembased on a distributed P2P signal processing framework can make efficient use of scarceenergy and communication resources and achieve target tracking successfully.
Development of a Fully Automated, GPS Based Monitoring System for Disaster Prevention and Emergency Preparedness: PPMS+RT
Authors: Bond Jason , Kim Don , Chrzanowski Adam , Szostak-Chrzanowski Anna
Published: October 2008

The increasing number of structural collapses, slope failures and other naturaldisasters has lead to a demand for new sensors, sensor integration techniques and dataprocessing strategies for deformation monitoring systems. In order to meet extraordinaryaccuracy requirements for displacement detection in recent deformation monitoringprojects, research has been devoted to integrating Global Positioning System (GPS) as amonitoring sensor. Although GPS has been used for monitoring purposes worldwide,certain environments pose challenges where conventional processing techniques cannotprovide the required accuracy with sufficient update frequency. Described is thedevelopment of a fully automated, continuous, real-time monitoring system that employsGPS sensors and pseudolite technology to meet these requirements in such environments.Ethernet and/or serial port communication techniques are used to transfer data betweenGPS receivers at target points and a central processing computer. The data can beprocessed locally or remotely based upon client needs. A test was conducted that illustrateda 10 mm displacement was remotely detected at a target point using the designed system.This information could then be used to signal an alarm if conditions are deemed to beunsafe.
Motion Estimation Using the Single-row Superposition-type Planar Compound-like Eye
Authors: Cheng Chi-Cheng , Lin Gwo-Long
Published: October 2008

How can the compound eye of insects capture the prey so accurately andquickly? This interesting issue is explored from the perspective of computer vision insteadof from the viewpoint of biology. The focus is on performance evaluation of noiseimmunity for motion recovery using the single-row superposition-type planar compound-like eye (SPCE). The SPCE owns a special symmetrical framework with tremendousamount of ommatidia inspired by compound eye of insects. The noise simulates possibleambiguity of image patterns caused by either environmental uncertainty or low resolutionof CCD devices. Results of extensive simulations indicate that this special visualconfiguration provides excellent motion estimation performance regardless of themagnitude of the noise. Even when the noise interference is serious, the SPCE is able todramatically reduce errors of motion recovery of the ego-translation without any type offilters. In other words, symmetrical, regular, and multiple vision sensing devices of thecompound-like eye have statistical averaging advantage to suppress possible noises. Thisdiscovery lays the basic foundation in terms of engineering approaches for the secret of thecompound eye of insects.
Methods for Solving Gas Damping Problems in Perforated Microstructures Using a 2D Finite-Element Solver
Authors: Veijola Timo , Raback Peter
Published: October 2008

We present a straightforward method to solve gas damping problems for perfo-rated structures in two dimensions (2D) utilising a Perforation Profile Reynolds (PPR) solver.The PPR equation is an extended Reynolds equation that includes additional terms modellingthe leakage flow through the perforations, and variable diffusivity and compressibility pro-files. The solution method consists of two phases: 1) determination of the specific admittanceprofile and relative diffusivity (and relative compressibility) profiles due to the perforation,and 2) solution of the PPR equation with a FEM solver in 2D. Rarefied gas corrections inthe slip-flow region are also included. Analytic profiles for circular and square holes withslip conditions are presented in the paper. To verify the method, square perforated damperswith 16 – 64 holes were simulated with a three-dimensional (3D) Navier-Stokes solver, a ho-mogenised extended Reynolds solver, and a 2D PPR solver. Cases for both translational (innormal to the surfaces) and torsional motion were simulated. The presented method extendsthe region of accurate simulation of perforated structures to cases where the homogenisationmethod is inaccurate and the full 3D Navier-Stokes simulation is too time-consuming.
Comparative Study of Protein Immobilization Properties on Calixarene Monolayers
Authors: Chen Hongxia , Lee Minsu , Choi Sungwook , Kim Jae-Ho , Choi Heung-Jin , Kim Sung-Hoon , Lee Jeabeom , Koh Kwangnak
Published: October 2008

Three calix[4]arene (Cal-4) derivatives of which contain ethylester (1),carboxylic acid (2), and crownether (3) at the lower rim with a common reactive thiol at theupper rim were synthesized and constructed to self-assembled monolayers (SAMs) on Aufilms. After spectroscopic characterization of monolayers, the interaction between Cal-4and surface confined bovine serum albumin (BSA) in the SAMs was analyzed by surfaceplasmon resonance (SPR). The estimated surface concentration of BSA on the Cal-4 SAMwith crownether group was the highest among the three Cal-4 derivatives. Anti-hIgG andhIgG pair was employed for the investigation of protein-protein interaction. Molecularinteraction between anti-hIgG and hIgG can be detected in a concentration range of 10pg/mL to 200 pg/mL on the Cal-4 derivative 3 SAM modified SPR chip.
Monitoring of ULF (Ultra-Low-Frequency) Geomagnetic Variations Associated with Earthquakes
Authors: Hayakawa Masashi , Hattori Katsumi , Ohta Kenji
Published: October 2008

ULF (ultra-low-frequency) electromagnetic emission is recently recognized as one of the most promising candidates for short-term earthquake prediction. This paper reviews previous convincing evidence on the presence of ULF emissions before a few large earthquakes. Then, we present our network of ULF monitoring in the Tokyo area by describing our ULF magnetic sensors and we finally present a few, latest results on seismogenic electromagnetic emissions for recent large earthquakes with the use of sophisticated signal processings.
Indium Tin Oxide-Polyaniline Biosensor: Fabrication and Characterization
Authors: Tahir Zarini  Muhammad , Alocilja Evangelyn  C. , Grooms Daniel   L.
Published: October 2008

In this study, a novel indium tin oxide (ITO)-polyaniline (Pani) biosensor wasdesigned, fabricated, and characterized. Initial testing was conducted for the detection ofbovine viral diarrhea virus (BVDV). The biosensor design was based upon the specific natureof antibodies to capture the target virus, and the conductive properties of self-doped Pani totranslate the antibody-antigen binding into a quantifying signal. The first part of the study wasto assess the feasibility of the self-doped Pani to be incorporated into the biosensor design byevaluating its several parameters, such as conductivity, physical structure, thermogravimetricproperties, and antibody-binding properties. The second part of the paper highlights thefabrication of the ITO-Pani biosensor to detect the presence of bovine viral diarrhea virus(BVDV) in pure culture. Although only BVDV culture was tested in this study, the biosensoris versatile for the detection of other pathogen of interest by changing the specificity of theantibodies.