bluuebunny/crossref_metadata_2025 huggingface dataset:
Statistical Modeling of Spatio-Temporal Variability in Monthly Average Daily Solar Radiation over Turkey
Authors: Evrendilek Fatih , Ertekin Can
Published: October 2008

Though one of the most significant driving forces behind ecological processessuch as biogeochemical cycles and energy flows, solar radiation data are limited or non-existent by conventional ground-based measurements, and thus, often estimated from othermeteorological data through (geo)statistical models. In this study, spatial and temporalpatterns of monthly average daily solar radiation on a horizontal surface at the ground levelwere quantified using 130 climate stations for the entire Turkey and its conventionally-accepted seven geographical regions through multiple linear regression (MLR) models as afunction of latitude, longitude, altitude, aspect, distance to sea; minimum, maximum andmean air temperature and relative humidity, soil temperature, cloudiness, precipitation, panevapotranspiration, day length, maximum possible sunshine duration, monthly average dailyextraterrestrial solar radiation, and time (month), and universal kriging method. Theresulting 20 regional best-fit MLR models (three MLR models for each region) based onparameterization datasets had R2adj values of 91.5% for the Central Anatolia region to 98.0%for the Southeast Anatolia region. Validation of the best-fit MLR models for each region led to R2 values of 87.7% for the Mediterranean region to 98.5% for the Southeast Anatoliaregion. The best-fit anisotropic semi-variogram models for universal kriging as a result ofone-leave-out cross-validation gave rise to R2 values of 10.9% in July to 52.4% inNovember. Surface maps of monthly average daily solar radiation were generated overTurkey, with a grid resolution of 500 m x 500 m.
Robust Forecasting for Energy Efficiency of Wireless Multimedia Sensor Networks
Authors: Wang Xue , Ma Jun-Jie , Ding Liang , Bi Dao-Wei
Published: October 2008

An important criterion of wireless sensor network is the energy efficiency inspecified applications. In this wireless multimedia sensor network, the observations arederived from acoustic sensors. Focused on the energy problem of target tracking, this paperproposes a robust forecasting method to enhance the energy efficiency of wirelessmultimedia sensor networks. Target motion information is acquired by acoustic sensornodes while a distributed network with honeycomb configuration is constructed. Thereby,target localization is performed by multiple sensor nodes collaboratively through acousticsignal processing. A novel method, combining autoregressive moving average (ARMA)model and radial basis function networks (RBFNs), is exploited to perform robust targetposition forecasting during target tracking. Then sensor nodes around the target areawakened according to the forecasted target position. With committee decision of sensornodes, target localization is performed in a distributed manner and the uncertainty ofdetection is reduced. Moreover, a sensor-to-observer routing approach of the honeycombmesh network is investigated to solve the data reporting considering the residual energy ofsensor nodes. Target localization and forecasting are implemented in experiments.Meanwhile, sensor node awakening and dynamic routing are evaluated. Experimentalresults verify that energy efficiency of wireless multimedia sensor network is enhanced bythe proposed target tracking method.
Antimicrobial Peptides: New Recognition Molecules for Detecting Botulinum Toxins
Authors: Kulagina Nadezhda V. , Anderson George P. , Ligler Frances S. , Shaffer Kara M. , Taitt Chris Rowe
Published: October 2008

Many organisms secrete antimicrobial peptides (AMPs) for protection againstharmful microbes. The present study describes detection of botulinum neurotoxoids A, Band E using AMPs as recognition elements in an array biosensor. While AMP affinitieswere similar to those for anti-botulinum antibodies, differences in binding patterns wereobserved and can potentially be used for identification of toxoid serotype. Furthermore,some AMPs also demonstrated superior detection sensitivity compared to antibodies: toxoidA could be detected at 3.5 LD50 of the active toxin in a 75-min assay, whereas toxoids B andE were detected at 14 and 80 LD50 for their respective toxins.
Piezoelectric Biosensor for a Simple Serological Diagnosis of Tularemia in Infected European Brown Hares (Lepus europaeus)
Authors: Pohanka Miroslav , Treml František , Hubálek Martin , Banďouchová Hana , Beklová Miroslava , Pikula Jiří
Published: October 2008

Piezoelectric biosensor was used for diagnosis of infection by Francisellatularensis subsp. holarctica in European brown hares. Two kinds of experiments wereperformed in this study. First, sera from experimentally infected European brown hares(Lepus europaeus) were assayed by piezoelectric biosensor and the seventh day postinfection was found as the first one when statistically significant diagnosis of tularemia waspossible; all other sera collected from hares later than on day 7 following the infection werefound tularemia positive. Typing to classify the field strain of F. tularensis used for theexperimental infection was confirmed by proteome study. Second, sera from 35 Europeanbrown hare specimens sampled at hunting grounds and tested as tularemia positive by slowagglutination allowed diagnosis of tularemia by the piezoelectric biosensor. All these sera ofnaturally infected hares were found as tularemia positive, too. Efficacy of the piezoelectricbiosensor for the serological diagnosis of tularemia is discussed.
Study on a Concentric Tube Bulb Manometer and its Performance Compared to U-shaped Manometer
Authors: Daood Syed S. , Ijaz Aamir , Butt Muhammad  A.
Published: October 2008

This paper presents comparative study of a new type of manometer calledconcentric tube bulb (C.T.B) manometer. Its performance of measuring differential heightis studied against conventional U-shaped manometer. Pressure drops and mass flow ratesare calculated by taking various systems comprising of different flow measuring devicessuch as orifice and venturimeters using both U- shaped and C.T.B manometers.Comparison between the physically measured values of differential pressure drops andmass flow rates with the calculated values based on theoretical equations is also made.Experiments are carried out using mercury and CCl4 in these manometers as sensing fluids.Water is used as flowing fluid for mass flow rate and pressure drop measurements, whereasin gauge pressure measurements air is used.
Quantitative Accelerated Life Testing of MEMS Accelerometers
Authors: Bâzu Marius , Gălăţeanu Lucian , Ilian Virgil Emil , Loicq Jerome , Habraken Serge , Collette Jean-Paul
Published: October 2008

Quantitative Accelerated Life Testing (QALT) is a solution for assessing thereliability of Micro Electro Mechanical Systems (MEMS). A procedure for QALT is shownin this paper and an attempt to assess the reliability level for a batch of MEMSaccelerometers is reported. The testing plan is application-driven and contains combinedtests: thermal (high temperature) and mechanical stress. Two variants of mechanical stressare used: vibration (at a fixed frequency) and tilting. Original equipment for testing at tiltingand high temperature is used. Tilting is appropriate as application-driven stress, because thetilt movement is a natural environment for devices used for automotive and aerospaceapplications. Also, tilting is used by MEMS accelerometers for anti-theft systems. The testresults demonstrated the excellent reliability of the studied devices, the failure rate in the“worst case” being smaller than 10-7h-1.
Object-Based Classification of Ikonos Imagery for Mapping Large-Scale Vegetation Communities in Urban Areas
Authors: Mathieu Renaud , Aryal Jagannath , Chong Albert k.
Published: October 2008

Effective assessment of biodiversity in cities requires detailed vegetation maps.To date, most remote sensing of urban vegetation has focused on thematically coarse landcover products. Detailed habitat maps are created by manual interpretation of aerialphotographs, but this is time consuming and costly at large scale. To address this issue, wetested the effectiveness of object-based classifications that use automated imagesegmentation to extract meaningful ground features from imagery. We applied thesetechniques to very high resolution multispectral Ikonos images to produce vegetationcommunity maps in Dunedin City, New Zealand. An Ikonos image was orthorectified and amulti-scale segmentation algorithm used to produce a hierarchical network of image objects.The upper level included four coarse strata: industrial/commercial (commercial buildings),residential (houses and backyard private gardens), vegetation (vegetation patches larger than0.8/1ha), and water. We focused on the vegetation stratum that was segmented at moredetailed level to extract and classify fifteen classes of vegetation communities. The firstclassification yielded a moderate overall classification accuracy (64%, κ = 0.52), which ledus to consider a simplified classification with ten vegetation classes. The overallclassification accuracy from the simplified classification was 77% with a κ value close tothe excellent range (κ = 0.74). These results compared favourably with similar studies inother environments. We conclude that this approach does not provide maps as detailed as those produced by manually interpreting aerial photographs, but it can still extract ecologically significant classes. It is an efficient way to generate accurate and detailed maps in significantly shorter time. The final map accuracy could be improved by integrating segmentation, automated and manual classification in the mapping process, especially when considering important vegetation classes with limited spectral contrast.
Tempo-Spatial Patterns of Land Use Changes and Urban Development in Globalizing China: A Study of Beijing
Authors: Xie Yichun , Fang Chuanglin , Lin George C.S. , Gong Hongmian , Qiao Biao
Published: October 2008

This study examines the temporal and spatial changes in land use as aconsequence of rapid urban development in the city of Beijing. Using a combination oftechniques of remote sensing and GIS, the study identifies a substantial loss of plaindryland and a phenomenal expansion of urban construction land over the recent decade.Geographically, there is a clear shifting of urban construction land from the inner city tothe outskirts as a consequence of suburbanization. The outward expansion of the ring-roadsystem is found to be one of the most important driving forces explaining the temporal andspatial pattern of land use change. The uneven distribution of population stands as anotherfactor with significant correlation with land use change. The application of the techniquesof remote sensing and GIS can enhance the precision and comparability of research onland use change and urban transformation in China.
Novel Deployment Schemes for Mobile Sensor Networks
Authors: Chen Jiming , Li Shijian , Sun Youxian
Published: October 2008

Virtual Force Algorithm (VFA) is becoming a main solution to area coverage forhomogeneous wireless sensor networks with random distribution of mobile sensor nodes.Consider the factors of the convergence, the boundary in Region Of Interest (ROI), effec-tive distance of acting force and useless moving, etc, VFA is improved to overcome the aboveproblems. Furthermore, an expression of exponential function for the relationship of vir-tual force is proposed to converge rapidly. Extensive simulation results indicate that theseimproved VFA get better performance in coverage rate, moving energy consumption, conver-gence etc. than original VFA.
Enhanced Sensory Properties of a Multichannel Quartz Crystal Microbalance Coated with Polymeric Nanobeads
Authors: Pantalei Simone , Zampetti Emiliano , Macagnano Antonella , Bearzotti Andrea , Venditti Iole , Russo Maria  V.
Published: October 2008

In this study the sensorial performances of a four-channel quartz crystalmicrobalance implemented on a single quartz plate are reported and compared with those offour independent quartz crystal microbalances. Particular attention has been devoted to bothcross talk in responses and sensor sensitivity. A recently synthesized nanostructuredpolymer, poly[phenylacetylene-(co-2-hydroxyethyl methacrylate)], has been used aschemical interactive material. The interactions of our sensor system with relative humidityare also reported. The multichannel device shows a better homogeneity of the masssensitivity with a spread of the values less then 4% compared to a 50% spread observed inthe set of four microbalances.
Magnetostrictive Microcantilever as an Advanced Transducer for Biosensors
Authors: Fu Liling , Li Suiqiong , Zhang Kewei , Chen I-Hsuan , Petrenko Valery. A. , Cheng Zhongyang
Published: October 2008

The magnetostrictive microcantilever (MSMC) as a high-performance transducer was introduced for the development of biosensors. The principle and characterization of MSMC are presented. The MSMC is wireless and can be easily actuated and sensed using magnetic field/signal. More importantly, the MSMC exhibits a high Q value and works well in liquid. The resonance behavior of MSMC is characterized in air at different pressures and in different liquids, respectively. It is found that the Q value of the MSMC in water reaches about 40. Although the density and viscosity of the surrounding media affect the resonance frequency and the Q value of MSMC, the density has a stronger influence on the resonance frequency and the viscosity has a stronger influence on the Q value, which result in that, for MSMC in air at pressure of less than 100 Pa, the resonance frequency of MSMC is almost independent of the pressure, while the Q value increases with decreasing pressure. MSMC array was developed and characterized. It is experimentally demonstrated that the characterization of an MSMC array is as simple as the characterization of a single MSMC. A filamentous phage against Salmonella typhimurium was utilized as bio-recognition unit to develop an MSMC based biosensor. The detection of S. typhimurium in water demonstrated that the MSMC works well in liquid.
Monitoring Transport Across Modified Nanoporous Alumina Membranes
Authors: Penumetcha Sai  S. , Kona Ravikanth , Hardin Jonathan  L. , Molder Andrew  L. , Steinle Erich  D.
Published: October 2008

This paper describes the use of several characterization methods to examinealumina nanotubule membranes that have been modified with specific silanes. The functionof these silanes is to alter the transport properties through the membrane by changing thelocal environment inside the alumina nanotube. The presence of alkyl groups, either long(C18) or short and branched (isopropyl) hydrocarbon chains, on these silanes significantlydecreases the rate of transport of permeant molecules through membranes containingalumina nanotubes as monitored via absorbance spectroscopy. The presence of an ionicsurfactant can alter the polarity of these modified nanotubes, which correlates to anincreased transport of ions. Fluorescent spectroscopy is also utilized to enhance thesensitivity of detecting these permeant molecules. Confirmation of the alkylsilaneattachment to the alumina membrane is achieved with traditional infrared spectroscopy,which can also examine the lifetime of the modified membrane. The physical parameters ofthese silane-modified porous alumina membranes are studied via scanning electronmicroscopy. The alumina nanotubes are not physically closed off or capped by the silanesthat are attached to the alumina surfaces.
Tactile Fabric Panel in an Eight Zones Structure
Authors: Alsina Maria , Escudero Francesc , Margalef Jordi , Luengo Sonia
Published: October 2008

By introducing a percentage of conductive material during the manufacture ofsewing thread, it is possible to obtain a fabric which is able to detect variations in pressurein certain areas. In previous experiments the existence of resistance variations has beendemonstrated, although some constrains of cause and effect were found in the fabric. Theresearch has been concentrated in obtaining a fabric that allows electronic detection of itsshape changes. Additionally, and because a causal behavior is needed, it is necessary thatthe fabric recovers its original shape when the external forces cease. The structure of thefabric varies with the type of deformation applied. Two kinds of deformation aredescribed: those caused by stretching and those caused by pressure. This last type ofdeformation gives different responses depending on the conductivity of the object used tocause the pressure. This effect is related to the type of thread used to manufacture thefabric. So, if the pressure is caused by a finger the response is different compared to theresponse caused by a conductive object. Another fact that has to be mentioned is that apressure in a specific point of the fabric can affect other detection points depending on theforce applied. This effect is related to the fabric structure. The goals of this article arevalidating the structure of the fabric used, as well as the study of the two types ofdeformation mentioned before.
Recent Advances in High-Birefringence Fiber Loop Mirror Sensors
Authors: Frazão Orlando , Baptista José M. T. , Santos José L.
Published: October 2008

Recent advances in devices and applications of high-birefringence fiber loopmirror sensors are addressed. In optical sensing, these devices may be used as strain andtemperature sensors, in a separate or in a simultaneous measurement. Other describedapplications include: refractive index measurement, optical filters for interrogate gratingsstructures and chemical etching control. The paper analyses and compares different types ofhigh-birefringence fiber loop mirror sensors using conventional and microstructured opticalfibers. Some configurations are presented for simultaneous measurement of physicalparameters when combined with others optical devices, for example with a long periodgrating.
A Novel Gas Sensor Transducer Based on Phthalocyanine Heterojunction Devices
Authors: Muzikante Inta , Parra Vicente , Dobulans Rorijs , Fonavs Egils , Latvels Janis , Bouvet Marcel
Published: October 2008

Experimental data concerning the changes in the current-voltage (I-V) perfor-mances of a molecular material-based heterojunction consisting of hexadecafluorinatednickel phthalocyanine (Ni(F16Pc)) and nickel phthalocyanine (NiPc),(Au|Ni(F16Pc)|NiPc|Al) are introduced as an unprecedented principle of transduction for gassensing performances. The respective n- and p-type doped-insulator behaviors of therespective materials are supported, owing to the observed changes in surface potential(using the Kelvin probe method) after submission to electron donor (ammonia) and electronacceptor gases (ozone). On the other hand, the bilayer device exhibits strong variations inthe built-in potential of the junction and in its rectification ratio. Moreover, large increasesoccur in forward and reverse currents in presence of ammonia vapors. These make possiblea multimodal principle of detection controlled by a combined effect between theheterojunction and the NiPc|Al contact. Indeed, this metal/organic junction plays a criticalrole regarding the steady asymmetry of the I-V profiles during the device’s doping evenusing high ammonia concentrations. This approach offers a more sophisticated alternative tothe classically studied, but at times rather operation-limited, resistive gas sensors.
Effect of Electrical Contact on the Contact Residual Stress of a Microrelay Switch
Authors: Chen Yung-Chuan , Tsai Hsun-Heng , Lu Wei-Hua , Chen Li-Wen
Published: October 2008

This paper investigates the effect of electrical contact on the thermal contactstress of a microrelay switch. A three-dimensional elastic-plastic finite element model withcontact elements is used to simulate the contact behavior between the microcantilever beamand the electrode. A model with thermal-electrical coupling and thermal-stress coupling isused in the finite element analysis. The effects of contact gap, plating film thickness andnumber of switching cycles on the contact residual stress, contact force, plastic deformation,and temperature rise of the microrelay switch are explored. The numerical results indicatethat the residual stress increases with increasing contact gap or decreasing plating filmthickness. The results also show that the residual stress increases as the number of switchingcycles increases. A large residual stress inside the microcantilever beam can decrease thelifecycle of the microrelay.
Influence of Damping on the Dynamical Behavior of the Electrostatic Parallel-plate and Torsional Actuators with Intermolecular Forces
Authors: Lin Wen-Hui , Zhao Ya-Pu
Published: October 2008

The influence of damping on the dynamical behavior of the electrostaticparallel-plate and torsional actuators with the van der Waals (vdW) or Casimir force(torque) is presented. The values of the pull-in parameters and the number of theequilibrium points do not change whether there is damping or not. The ability ofequilibrium points is varied with the appearance of damping. One equilibrium point is anunstable saddle with a different damping coefficient, the other equilibrium point is astable node when the damping coefficient is greater than some critical value, andotherwise it is a stable focus. Then there are two heteroclinic orbits passing from theunstable saddle point to the stable node or focus.
State Key Laboratory of Nonlinear Mechanics (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080, China
Authors: Korostynska Olga , Arshak Khalil , Gill Edric , Arshak Arousian
Published: October 2008

This paper reviews current state-of-the-art methods of measuring pH levels that are based on polymer materials. These include polymer-coated fibre optic sensors, devices with electrodes modified with pH-sensitive polymers, fluorescent pH indicators, potentiometric pH sensors as well as sensors that use combinatory approach for ion concentration monitoring.
Reducing the Discrepancy Between ASTER and MODIS Land Surface Temperature Products
Authors: Liu Yuanbo , Yamaguchi Yasushi , Ke Changqing
Published: October 2008

Human-induced global warming has significantly increased the importance ofsatellite monitoring of land surface temperature (LST) on a global scale. The MODerate-resolution Imaging Spectroradiometer (MODIS) provides a 1-km resolution LST productwith almost daily coverage of the Earth, invaluable to both local and global change studies.The Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER) provides aLST product with a high spatial resolution of 90-m and a 16-day recurrent cycle,simultaneously acquired at the same height and nadir view as MODIS. ASTER andMODIS are complementary in resolution, offering a unique opportunity for scale-relatedstudies. ASTER and MODIS LST have been widely used but the errors in LST were mostlydisregarded. Correction of ASTER-to-MODIS LST discrepancies is essential for studiesreliant upon the joint use of these sensors. In this study, we compared three correctionapproaches: the Wan et al.’s approach, the refined Wan et al.’s approach, and thegeneralized split window (GSW) algorithm based approach. The Wan et al.’s approachcorrects the MODIS 1-km LST using MODIS 5-km LST. The refined approach modifiesthe Wan et al.’s approach through incorporating ASTER emissivity and MODIS 5-km data.The GSW algorithm approach does not use MODIS 5-km but only ASTER emissivity data. We examined the case over a semi-arid terrain area for the part of the Loess Plateau of China. All the approaches reduced the ASTER-to-MODIS LST discrepancy effectively. With terrain correction, the original ASTER-to-MODIS LST difference reduced from 2.7±1.28 K to -0.1±1.87 K for the Wan et al.’s approach, 0.2±1.57 K for the refined approach, and 0.1±1.33 K for the GSW algorithm based approach. Among all the approaches, the GSW algorithm based approach performed best in terms of mean, standard deviation, root mean square root, and correlation coefficient.
Development of a Space-charge-sensing System
Authors: Hazmi Ariadi , Takagi Nobuyuki , Wang Daohong , Watanabe Teiji
Published: October 2008

A system for remotely measuring the distribution of air space charge in real time is developed. The system consists of a loudspeaker and an electric field antenna. By propagating a burst of directional sound wave from the speaker, a modulation in the space charge and, therefore, an electric field change at ground is produced. The distribution of the space charge density is derived from the E-field change which can be measured by the E- field antenna. The developed system has been confirmed by both laboratory and field experiments.
Three Cavity Tunable MEMS Fabry Perot Interferometer
Authors: Parashar Avinash , Shah Ankur , Packirisamy Muthukumaran , Sivakumar Narayanswamy
Published: October 2008

In this paper a four-mirror tunable micro electro-mechanical systems (MEMS)Fabry Perot Interferometer (FPI) concept is proposed with the mathematical model. Thespectral range of the proposed FPI lies in the infrared spectrum ranging from 2400 to 4018(nm). FPI can be finely tuned by deflecting the two middle mirrors (or by changing the threecavity lengths). Two different cases were separately considered for the tuning. In case one,tuning was achieved by deflecting mirror 2 only and in case two, both mirrors 2 and 3 weredeflected for the tuning of the FPI.
Animals as Mobile Biological Sensors for Forest Fire Detection
Authors: Sahin Yasar Guneri
Published: October 2008

This paper proposes a mobile biological sensor system that can assist in earlydetection of forest fires one of the most dreaded natural disasters on the earth. The main ideapresented in this paper is to utilize animals with sensors as Mobile Biological Sensors(MBS). The devices used in this system are animals which are native animals living inforests, sensors (thermo and radiation sensors with GPS features) that measure thetemperature and transmit the location of the MBS, access points for wireless communicationand a central computer system which classifies of animal actions. The system offers twodifferent methods, firstly: access points continuously receive data about animals’ locationusing GPS at certain time intervals and the gathered data is then classified and checked tosee if there is a sudden movement (panic) of the animal groups: this method is called animalbehavior classification (ABC). The second method can be defined as thermal detection(TD): the access points get the temperature values from the MBS devices and send the datato a central computer to check for instant changes in the temperatures. This system may beused for many purposes other than fire detection, namely animal tracking, poachingprevention and detecting instantaneous animal death.
Fiber Optic Sensors For Detection of Toxic and Biological Threats
Authors: El-Sherif Mahmoud , Bansal Lalitkumar , Yuan Jianming
Published: October 2008

Protection of public and military personnel from chemical and biological warfareagents is an urgent and growing national security need. Along with this idea, we havedeveloped a novel class of fiber optic chemical sensors, for detection of toxic and biologicalmaterials. The design of these fiber optic sensors is based on a cladding modificationapproach. The original passive cladding of the fiber, in a small section, was removed and thefiber core was coated with a chemical sensitive material. Any change in the opticalproperties of the modified cladding material, due to the presence of a specific chemicalvapor, changes the transmission properties of the fiber and result in modal powerredistribution in multimode fibers. Both total intensity and modal power distribution (MPD)measurements were used to detect the output power change through the sensing fibers. TheMPD technique measures the power changes in the far field pattern, i.e. spatial intensitymodulation in two dimensions. Conducting polymers, such as polyaniline and polypyrrole,have been reported to undergo a reversible change in conductivity upon exposure tochemical vapors. It is found that the conductivity change is accompanied by optical propertychange in the material. Therefore, polyaniline and polypyrrole were selected as the modifiedcladding material for the detection of hydrochloride (HCl), ammonia (NH3), hydrazine(H4N2), and dimethyl-methl-phosphonate (DMMP) {a nerve agent, sarin stimulant},respectively. Several sensors were prepared and successfully tested. The results showeddramatic improvement in the sensor sensitivity, when the MPD method was applied. In thispaper, an overview on the developed class of fiber optic sensors is presented and supportedwith successful achieved results.
Lanthanide Recognition: an Asymetric Erbium Microsensor Based on a Hydrazone Derivative
Authors: Faridbod Farnoush , Ganjali Mohammad  Reza , Larijani Bagher , Norouzi Parviz , Riahi S. , Mirnaghi F.  Fatemeh Sadat
Published: October 2008

N'-(2-hydroxy-1,2-diphenylethylidene)benzohydrazide (HDB) was found tohave a very selective and sensitive behavior towards erbium(III) ions, in comparison tothirteen lanthanide ions, inner transition and representative metal ions and was hence usedas a neutral ion carrier in construction of an Er(III) microelectrode. Theoretical calculationsand conductance studies of HDB to erbium and some other metal ions were carried out andconfirmed selectivity toward Er(III) ions.The best performance was obtained with a membrane contain 3% potassium tetrakis(p-chlorophenyl)borate (KTpClPB) as an anionic additive, 72% dibutyl phthalate (DBP) assolvent mediator, 5% HDB, and 20% poly(vinyl chloride) (PVC). The proposed Er(III)microelectrode exhibits a near Nernstian response of 17.5±0.5 mV per decade of erbiumactivity, and a very wide linear range 1.0×10-3-3.0×10-10 M. It can work well in the pHrange of 3.0-9.0. The lower detection limit (LDL) of the microelectrode was calculated tobe 2.0×10-10 M.
Non-Destructive Evaluation of Historical Paper Based on pH Estimation from VOC Emissions
Authors: Strlič Matija , Cigić Irena Kralj , Kolar Jana , De Bruin Gerrit , Pihlar Boris
Published: October 2008

Volatile organic compounds (VOCs) emitted from materials during degradationcan be a valuable source of information. In this work, the emissions of furfural and aceticacid from cellulose were studied using solid-phase micro-extraction (SPME) incombination with gas chromatography-mass spectrometry. Two sampling techniques wereemployed: static headspace sampling using SPME for 1 h at 40 oC after 18-h samplepreparation at 80 oC in a closed glass vial, and contact SPME in a stack of paper (or abook). While a number of VOCs are emitted from paper under conditions of natural oraccelerated degradation, two compounds were confirmed to be of particular diagnosticvalue: acetic acid and furfural. The emissions of furfural are shown to correlate with pH ofthe cellulosic environment. Since pH is one of the most important parameters regardingdurability of this material, the developed method could be used for non-destructiveevaluation of historical paper.
About Optimal Fractional Hold Circuits for Inter- sample Output Reconstruction in Sampled-data Systems
Authors: De la Sen Manuel
Published: October 2008

The design of fractional order-holds (FROH) of correcting gains β ∈ [ − 1 , 1 ](potentially and possibly including zero-order-holds, ZOH with β=0, and first-order-holds,FROH with β=1) is discussed related to achieving output deviations being close withrespect to its sampled values. A squared error time- integral between the current output andits sampled values is minimized to yield the appropriate correcting gain of the FROH in ananalytic way.
Near-Field Thermometry Sensor Based on the Thermal Resonance of a Microcantilever in Aqueous Medium
Authors: Kim Seonghwan , Kim Kyung Chun , Kihm Kenneth David
Published: October 2008

A new concept using a near-field thermometry sensor is presented, employing atipless microcantilever experimentally validated for an aqueous medium within approximatelyone cantilever width from the solid interface. By correlating the thermal Brownian vibratingmotion of the microcantilever with the surrounding liquid temperature, the near-fieldmicroscale temperature distributions at the probing site are determined at separation distancesof z = 5, 10, 20, and 40 μm while the microheater temperature is maintained at 50°C, 70°C, or90°C. In addition, the near-field correction of the correlation is discussed to account for thequenched cantilever vibration frequencies, which are quenched due to the no-slip solid-wallinterference. Higher thermal sensitivity and spatial resolution is expected when the vibrationfrequencies increase with a relatively short and thick cantilever and the dimensions of themicrocantilever are reduced. Use of the microcantilever thermometry sensor can also reduce thecomplexity and mitigate the high cost associated with existing microfabricated thermocouplesor thermoresistive sensors.
Thermally Stable Merocyanine Form of Photochromic Spiropyran with Aluminum Ion as a Reversible Photo-driven Sensor in Aqueous Solution
Authors: Ren Jiaqiang , Tian He
Published: October 2008

A reversible photo-driven sensor for aluminum ions based on photochromicspiropyran was reported with rapid response time. The detection of aluminum wasperformed via the chelation of aluminum ions with the merocyanine form (MC) ofphotochromic spiropyran. 1H NMR studies confirmed the conversation from the MC forminto the Al3+ -MC form. Addition of aluminum ions to the spiropyran (SP) in a MeCN/H2Omixture results in obvious color changes with a loss in absorbance at 539 nm and anenhancement in absorbance at about 420 nm after irradiation at 365 nm. The metal chelationcomplex (Al3+ -MC) can also be converted into the original SP form by irradiation withvisible light. Aluminum ions can be detected down to 0.5 μM levels in a fast response ofless than 5 seconds with no interference from other ionic species.
Fuzzy Logic Control Based QoS Management in Wireless Sensor/Actuator Networks
Authors: Xia Feng , Zhao Wenhong , Sun Youxian , Tian Yu-Chu
Published: October 2008

Wireless sensor/actuator networks (WSANs) are emerging rapidly as a newgeneration of sensor networks. Despite intensive research in wireless sensor networks(WSNs), limited work has been found in the open literature in the field of WSANs. Inparticular, quality-of-service (QoS) management in WSANs remains an important issue yetto be investigated. As an attempt in this direction, this paper develops a fuzzy logic controlbased QoS management (FLC-QM) scheme for WSANs with constrained resources and indynamic and unpredictable environments. Taking advantage of the feedback controltechnology, this scheme deals with the impact of unpredictable changes in traffic load on theQoS of WSANs. It utilizes a fuzzy logic controller inside each source sensor node to adaptsampling period to the deadline miss ratio associated with data transmission from the sensorto the actuator. The deadline miss ratio is maintained at a pre-determined desired level sothat the required QoS can be achieved. The FLC-QM has the advantages of generality,scalability, and simplicity. Simulation results show that the FLC-QM can provide WSANswith QoS support.
Design Considerations for Aural Vital Signs Using PZT Piezoelectric Ceramics Sensor Based on the Computerization Method
Authors: Noimanee Suranan , Tunkasiri Tawee , Siriwitayakorn Kingkeo , Tantrakoon Jerapong
Published: October 2008

The purpose was to illustrate how system developed for measurement of the aural vital signs such as patient’s heart and lung sounds in the hospital. For heart sounds measurement must operate the frequency response between 20 – 800 Hz, and lung sounds measurement must operate the frequency response between 160 – 4,000 Hz. The method was designed PZT piezoelectric ceramics for both frequency response in the same PZT sensor. It converts a signal from aural vital sign form to voltage signal. The signal is suitably amplified and re-filtered in band pass frequency band. It is converted to digital signal by an analog to digital conversion circuitry developed for the purpose. The results were that all signals can fed to personal computer through the sound card port. With the supporting software for drawing of graphic on the screen, the signal for a specific duration is accessed and stored in the computer’s memory in term of each patient’s data. In conclusion, the data of each patient call dot pcg (.pcg) for drawing graph and dot wave (.wave) for sound listening or automatic sending via electronic mail to the physician for later analysis of interpreting the sounds on the basis of their time domain and frequency domain representation to diagnose heart disorders.
Remote Sensing Sensors and Applications in Environmental Resources Mapping and Modelling
Authors: Melesse Assefa M. , Weng Qihao , Thenkabail Prasad S. , Senay Gabriel B.
Published: October 2008

The history of remote sensing and development of different sensors for environmental and natural resources mapping and data acquisition is reviewed and reported. Application examples in urban studies, hydrological modeling such as land-cover and floodplain mapping, fractional vegetation cover and impervious surface area mapping, surface energy flux and micro-topography correlation studies is discussed. The review also discusses the use of remotely sensed-based rainfall and potential evapotranspiration for estimating crop water requirement satisfaction index and hence provides early warning information for growers. The review is not an exhaustive application of the remote sensing techniques rather a summary of some important applications in environmental studies and modeling.
Integrating Map Algebra and Statistical Modeling for Spatio- Temporal Analysis of Monthly Mean Daily Incident Photosynthetically Active Radiation (PAR) over a Complex Terrain
Authors: Evrendilek Fatih
Published: October 2008

This study aims at quantifying spatio-temporal dynamics of monthly mean dailyincident photosynthetically active radiation (PAR) over a vast and complex terrain such asTurkey. The spatial interpolation method of universal kriging, and the combination ofmultiple linear regression (MLR) models and map algebra techniques were implemented togenerate surface maps of PAR with a grid resolution of 500 x 500 m as a function of fivegeographical and 14 climatic variables. Performance of the geostatistical and MLR modelswas compared using mean prediction error (MPE), root-mean-square prediction error(RMSPE), average standard prediction error (ASE), mean standardized prediction error(MSPE), root-mean-square standardized prediction error (RMSSPE), and adjustedcoefficient of determination (R2adj.). The best-fit MLR- and universal kriging-generatedmodels of monthly mean daily PAR were validated against an independent 37-year observeddataset of 35 climate stations derived from 160 stations across Turkey by the Jackknifingmethod. The spatial variability patterns of monthly mean daily incident PAR were moreaccurately reflected in the surface maps created by the MLR-based models than in thosecreated by the universal kriging method, in particular, for spring (May) and autumn(November). The MLR-based spatial interpolation algorithms of PAR described in thisstudy indicated the significance of the multifactor approach to understanding and mappingspatio-temporal dynamics of PAR for a complex terrain over meso-scales.
Detection of Brominated By-Products Using a Sensor Array Based on Nanostructured Thin Films of Conducting Polymers
Authors: Carvalho Eduarda Regina , Consolin Filho Nelson , Venancio Everaldo Carlos , O. Osvaldo N. , Mattoso Luiz H. C. , Martin-Neto Ladislau
Published: October 2008

The detection of the carcinogenic trihalomethanes (THM) in public water supplysystems using low-cost equipment has become an essential feature, since these compoundsmay be generated as by-products of water-treatment processes. Here we report on a sensorarray that extends the concept of an “electronic tongue” to detect small amounts ofbromoform, bromodichloromethane and dibromochloromethane, with detection limits aslow as 0.02 mg L-1. The sensor array was made up of 10 sensing units, in whichnanostructured films of conducting and natural polymers were deposited onto goldinterdigitated electrodes. The principle of detection was impedance spectroscopy, withmeasurements carried out in the range between 1 Hz to 1 MHz. Using data at 1 kHz, atwhich the electrical response varied considerably by changing the analyte, we demonstratedwith principal component analysis (PCA) that samples with the 3 brominatedtrihalomethanes can be distinguished from each other and for various concentrations.
PVC Membrane Sensors for Potentiometric Determination of Acebutolol
Authors: Mostafa Gamal Abdel-Hafiz , Hefnawy Mohamed Mahmoud , Al-Majed Abdulrahman
Published: October 2008

The construction and general performance characteristics of two novelpotentiometric membrane sensors responsive to the acebutolol are described. Thesensors are based on the use of ion-association complexes of acebutolol (AC) withtetraphenylborate(TPB) (I) and phosphomolybdate(PM) (II) as exchange sites in a PVCmatrix. The sensors show a fast, stable and near- Nernstian for the mono charge cationof AC over the concentration range 1×10-3 - ~10-6 M at 25 °C over the pH range 2.0 -6.0 with cationic slope of 51.5 ± 0.5 and 53.0 ± 0.5 per concentration decade for AC-Iand AC-II sensors respectively. The lower detection limit is 6×10-6 M and 4×0-6 M withthe response time 20-30 s in the same order of both sensors. Selectivity coefficients ofAC related to a number of interfering cation and some organic compounds wereinvestigated. There are negligible interferences are caused by most of the investigatedspecies. The direct determination of 3 - 370 μg/ml of AC shows an average recovery of 99.4 and 99.5% and a mean relative standard deviation of 1 . 5 % at 100.0 μg/ml forsensor I and II respectively. The results obtained by determination of AC in tablets usingthe proposed sensors which comparable favorably with those obtained by the Britishpharmacopoeia method. In the present investigation the electrodes have been utilized asend point indicator for some precipitation titration reactions.
From Hearing to Listening: Design and Properties of an Actively Tunable Electronic Hearing Sensor
Authors: Stoop Ruedi , Jasa Tom , Uwate Yoko , Martignoli Stefan
Published: October 2008

An important step towards understanding the working principles of the mammalian hearing sensor is the concept of an active cochlear amplifier. Theoretical arguments and physiological measurements suggest that the active cochlear amplifiers originate from systems close to a Hopf bifurcation. Efforts to model the mammalian hearing sensor on these grounds have, however, either had problems in reproducing sufficiently close essential aspects of the biological example (Magnasco, M.O. Phys. Rev. Lett. 90, 058101 (2003); Duke, T. & Jülicher, F. Phys. Rev. Lett. 90, 158101 (2003)), or required complicated spatially coupled differential equation systems that are unfeasible for transient signals (Kern, A. & Stoop, R. Phys. Rev. Lett. 91, 128101 (2003)). Here, we demonstrate a simple system of electronically coupled Hopf amplifiers that not only leads to the desired biological response behavior, but also has real-time capacity. The obtained electronic Hopf cochlea shares all salient signal processing features exhibited by the mammalian cochlea and thus provides a simple and efficient design of an artificial mammalian hearing sensor.
Gold Nanoparticles With Special Shapes: Controlled Synthesis, Surface-enhanced Raman Scattering, and The Application in Biodetection
Authors: Hu Jianqiang , Wang Zhouping , Li Jinghong
Published: October 2008

Specially shaped gold nanoparticles have intrigued considerable attention becausethey usually possess high-sensitivity surface-enhanced Raman scattering (SERS) and thusresult in large advantages in trace biodetermination. In this article, starch-capped goldnanoparticles with hexagon and boot shapes were prepared through using a nontoxic andbiologically benign aqueous-phase synthetic route. Shape effects of gold nanoparticles onSERS properties were mainly investigated, and found that different-shaped goldnanoparticles possess different SERS properties. Especially, the boot-shaped nanoparticlescould induce more 100-fold SERS enhancements in sensitivity as compared with those fromgold nanospheres. The extremely strong SERS properties of gold nanoboots have beensuccessfully applied to the detection of avidin. The unique nanoboots with high-sensitivitySERS properties are also expected to find use in many other fields such as biolabel,bioassay, biodiagnosis, and even clinical diagnosis and therapy.
Evaluation of Grassland Dynamics in the Northern-Tibet Plateau of China Using Remote Sensing and Climate Data
Authors: Zhang Jiahua , Yao Fengmei , Zheng Lingyun , Yang Limin
Published: October 2008

The grassland ecosystem in the Northern-Tibet Plateau (NTP) of China is verysensitive to weather and climate conditions of the region. In this study, we investigate thespatial and temporal variations of the grassland ecosystem in the NTP using theNOAA/AVHRR ten-day maximum NDVI composite data of 1981-2001. The relationshipsamong Vegetation Peak-Normalized Difference Vegetation Index (VP-NDVI) and climatevariables were quantified for six counties within the NTP. The notable and unevenalterations of the grassland in response to variation of climate and human impact in theNTP were revealed. Over the last two decades of the 20th century, the maximum greennessof the grassland has exhibited high increase, slight increase, no-change, slight decrease andhigh decrease, each occupies 0.27%, 8.71%, 77.27%, 13.06% and 0.69% of the total area ofthe NTP, respectively. A remarkable increase (decrease) in VP-NDVI occurred in thecentral-eastern (eastern) NTP whereas little change was observed in the western andnorthwestern NTP. A strong negative relationship between VP-NDVI and ET0 was foundin sub-frigid, semi-arid and frigid- arid regions of the NTP (i.e., Nakchu, Shantsa, Palgonand Amdo counties), suggesting that the ET0 is one limiting factor affecting grasslanddegradation. In the temperate-humid, sub-frigid and sub-humid regions of the NTP (Chaliand Sokshan counties), a significant inverse correlation between VP-NDVI and populationindicates that human activities have adversely affected the grassland condition as waspreviously reported in the literature. Results from this research suggest that the alterationand degradation of the grassland in the lower altitude of the NTP over the last two decades of the 20th century are likely caused by variations of climate and anthropogenic activities.
pH Sensitivity of Novel PANI/PVB/PS3 Composite Films
Authors: Gill Edric , Arshak Arousian , Arshak Khalil , Korostynska Olga
Published: October 2008

This paper reports on the results from the investigation into the pH sensitivity ofnovel PANI/PVB/PS3 composite films. The conductimetric sensing mode was chosen as itis one of the most promising alternatives to the mainstream pH-sensing methods and it is theleast investigated due to the popularity of other approaches. The films were deposited usingboth screen-printing and a drop-coating method. It was found that the best response to pHwas obtained from the screen-printed thick films, which demonstrated a change inconductance by as much as three orders of magnitude over the pH range pH2-pH11. Thedevices exhibited a stable response over 96 hours of operation. Several films were immersedin buffer solutions of different pH values for 96 hours and these were then investigated usingXPS. The resulting N 1s spectra for the various films confirmed that the change inconductance was due to deprotonation of the PANI polymer backbone. SEM andProfilometry were also undertaken and showed that no considerable changes in themorphology of the films took place and that the films did not swell or contract due toexposure to test solutions.