bluuebunny/crossref_metadata_2025 huggingface dataset:
A Method for Damage Detection Based on Correlation Characteristic of Acceleration Response
Authors: Yan Wei Ming , Gu Da Peng , Chen Yan Jiang , Wang Wei Ning
Published: March 2013

A damage detection method using BP neural network based on a novel damage index, the correlation characteristic of the acceleration response, is proposed, and is evaluated through the FEM simulation and experiment verification. On the basis of achievements in existence, the feasibility of using the correlation characteristic as damage index is validated theoretically. The damage detection for a simple-supported beam using the proposed method was FEM simulated. The results showed that the trained BP neural network can correctly detect the location and extent of damages in both single damage case and multi-damage case. A model test of a reinforced concrete simple-supported beam was performed to verify the validity and efficiency of the damage detection method. From the results of the model test, it is shown that the trained BP neural network can correctly locate the damage mostly detect the extent of damage. A conclusion is given that the novel damage detection method using the correlation characteristic of the acceleration response as damage index is feasible and efficient.
Gelatin Coated 45S5 Bioglass®-Derived Scaffolds for Bone Tissue Engineering
Authors: Metze Anke Lisa , Grimm Alexandra , Nooeaid Patcharakamon , Roether Judith A. , Hum Jasmin , Newby Phillipa J. , Schubert Dirk W. , Boccaccini Aldo Roberto
Published: March 2013

Highly porous 45S5 Bioglass® scaffolds were fabricated by the foam replica method and successfully coated with a well attached gelatin layer by dipping and pipetting methods. Depending on macropore size of the scaffold and gelatin concentration, mechanically enhanced scaffolds with improved compressive strength in comparison to uncoated scaffolds could be obtained while preserving the high and interconnected porosity that is required for bone in-growth. Moreover, the scaffolds bioactivity by immersion in simulated body fluid (SBF) was investigated showing that gelatin coating preserves the intrinsic bioactivity of the Bioglass® scaffold. It was also shown that the gelatin layer can be loaded with tetracycline hydrochloride for developing scaffolds with drug delivery capability.
Application of Selected Multiaxial High-Cycle Fatigue Criteria to Rolling Contact Problems
Authors: Romanowicz Paweł
Published: March 2013

The risk of fatigue failure of elements working in rolling contact conditions (such as railway wheels, rolling bearings, etc.) is a significant issue with respect to safety and economy. In this case the complex and non-proportional stress state with pulsating three dimensional compression occurs. Therefore, the analysis of fatigue life of structures working in rolling contact conditions can be performed using recently proposed multiaxial high-cycle fatigue criteria. However, there is no hypothesis that could be universally accepted for calculations of fatigue strength. Furthermore, not all criteria proposed in literature for rolling contact fatigue (RCF) analysis can predict it. In the paper, the most popular criteria based on different theories are investigated in the application to RCF problem. Moreover, modification of the popular Dang Van hypothesis is proposed. The problem of free and tractive rolling contact fatigue is analysed on the example of a cylindrical crane wheel and spherical thrust roller bearing.
Synthesis of the Active Cab Suspension Mechanism
Authors: Tora Grzegorz
Published: March 2013

In the context of growing ergonomic concerns and pressing competition on the market, designing machines and vehicles offering a better operator comfort has become a major trend in development of heavy machines and vehicles. During the ride over the rough terrain, the cab is subjected to excitations in the form of low-frequency and high-amplitude vibration. This study investigates the vibration reduction strategy whereby the machine structure should incorporate an active suspension of the cab. An actuating mechanism is incorporated, connected to the machine frame and the cab and placed in between. This paper provides a synthesis of dimensions of the actuator links such that the imposed constraints and conditions should be satisfied. A numerical example is provided in the study of a Caterpillar 924 Gz loader.
Defects in Single Walled Carbon Nanotubes (SWCNT)
Authors: Banaś Aleksander , Muc Aleksander , Chwał Małgorzata
Published: March 2013

In the paper the stress-strain of pristine and defective single walled carbon nanotubes are investigated. The defects are in the form of point vacancies. The axial deformations of structures are studied only. A special attention is focused on the effects of material and geometrical properties of nanostructures on the results.
Piezoelectric Transducers
Authors: Kędziora Piotr , Barski Marek , Chwał Małgorzata
Published: March 2013

Piezoelectric materials are used as layers or fibers that are embedded within or bonded to the surfaces of a structure. Piezoelectric transducers can be made in the different shapes. Piezoelectric elements are mainly made of polymer or ceramic materials.
Advantages of the Use of Metal Foams for Electromagnetic Shielding
Authors: Íñiguez J. , Raposo V. , García Flores Ana , Zazo M. , Hernández-Gómez Pablo
Published: March 2013

Metal foams are very interesting materials in new emerging technologies as aeronautic, spatial research, auto-motion or heat exchanger, but there are other areas in which these materials could be advantageous. Here is a new proposal for using these materials in electromagnetic shielding. The goal is to demonstrate that, although having a smaller effective electrical conductivity than massive materials, it is possible to attain operative electromagnetic shielding with a reduction of mass and, in addition, to bring together in a single product a supplementary protection against vibrations, impact, noise, etc., as corresponds to the well-known properties of porous materials. In terms of the operating frequency, conductivity and thickness of the metallic foams the electromagnetic screening was calculated. It is shown how to guarantee a specified shielding the necessary thickness in porous materials with respect to massive metals obeys to a quadratic relation.
Intelligent Metal Detector
Authors: Nováček Petr , Svatoš Jakub
Published: March 2013

Humanitarian demining is a matter of high interest, but metal contamination and magnetic soils reduce the sensitivity of metal detectors. The soil contamination also increases the numbers of false alarms which, in some areas, account for as much as 99.9 % of all alarms. The decrease of false alarms is therefore attractive. Our solution is capable to be adapted and utilized with current professional metal detectors. Essentially it consists of several modules with modular structure, where the master module is always necessary in all applications and the navigation module has to be connected in cases where position estimation is required. Searching part of the detector is able to work in continuous wave mode with variable excitation signal and the possibility to utilize more carrier frequencies. Furthermore, the modular structure can use different search heads available on the market as well as heads developed for special purposes. The modular metal and mine detector described is capable to detect not only unexploded ordnance and explosive remnants of wars, but also pipes and wires in walls and floors indoor which is useful property during not only buildings reconstructions.
Investigation of Gas Sensing Materials SnO2/In2O3 Composite Nanofibers Treated by Oxygen Plasma
Authors: Du Hai Ying , Wang Jing , Yao Peng Jun , Zhao Lin , Tang Zhe Nan
Published: March 2013

SnO2/In2O3 composite nanofibers were synthesized by using an electrospinning system with double jets, then, treated by oxygen plasma. The morphology and structure of treated composite nanofibers were analyzed by SEM and XRD. The treated composite nanofibers showed more irregular and rough. The porosity of the treated composite nanofibers was bigger than the one of untreated. The gas sensing properties of the composite nanofibers to formaldehyde were measured before and after materials treated by oxygen plasma. The treated composite nanofibers exhibit large response values. Cross-responses and humidity effection of the treated composite nanofibers sensor were tested. The sensing mechanism of the SnO2/In2O3 composite nanofibers gas sensor treated by oxygen plasma was briefly analyzed.
Speciﬁc Conductance Characteristic of Force Sensing Resistor (FSR) with Custom Made Single-Gap Conductive Contacts
Authors: Krklješ Damir , Babković Kalman , Nagy László F.
Published: March 2013

This paper investigates the force-dependent contact area excitation of the standardForce Sensing Resistor (Interlink FSR) with modiﬁed conductive contacts. The force dependentarea excitation was accomplished by the deformation of a dome shaped rubber element. Thecharacteristic of the FSR - the pressure dependency of its speciﬁc conductance (per length)was experimentally obtained from the ﬁxed contact area excitation. The power law function,chosen to represent the characteristic, is then ﬁtted to experimental results. Veriﬁcation ofthe characteristic was done by comparing the measured and predicted values of the sensorconductance when the force-dependent excitation is applied.
Building Functional Surfaces for Biosensors Development
Authors: Morón Carlos , Garcia Alfonso , Tremps Enrique , Somolinos Jose Andrés
Published: March 2013

Polyelectrolyte multilayers (PEM) built by layer-by-layer technique have been extensively studied over the last years, resulting in a wide variety of current and potential applications. This technique can be used to construct thin films with different functionalities, or to functionalize surfaces with substantial different properties of those of the underlying substrates. The multilayering process is achieved by the alternate adsorption of oppositely charged polyelectrolytes. In this work we get advantage of the protein resistant property of the Poly (l-lysine)-graft-(polyethyleneglycol) to create protein patterns. Proteins can be immobilized on a surface by unspecific physical adsorption, covalent binding or through specific interactions. The first protein used in this work was laccase, a copper-containing redox enzyme that catalyse the oxidation of a broad range of polyphenols and aromatic substrates, coupled to the reduction of O2 to H2O without need of cofactors. Applications of laccases have been reported in food, pulp, paper, and textile industry, and also in biosensor development. Some uses require the immobilization of the enzyme on solid supports by adsorption, covalent attachment, entrapment, etc, on several substrates. Especially for biosensor development, highly active, stable and reproducible immobilization of laccase is required.
Measurement and Monitoring System for Level of Groundwater
Authors: Brkic Miodrag , Obradovic Djordje , Dudarin Zorica , Károly Barta , Živanov Miloš B.
Published: March 2013

In this paper, we present a system for measuring and monitoring of groundwater level. Level of groundwater is needed to create hydrodynamic models of inland excess water, which causes significant environmental and economic problem worldwide, because large parts of the flat terrain can be covered by inland excess water. On areas of interest, continuous measurement of groundwater level on several measurement points over long periods of time (several years) is needed as input data for hydrodynamic models. Measurements of groundwater level are made by acoustic system, which measure time of travel of sound to and from level of water inside wells. Every measurement point is equipped with GPRS transceiver, which sends data over GSM network to server connected to internet. Software on server collects and saves measured data in databases in adequate data format. Prototype of system is made, and hardware and software realization, communicating network and measurement results are presented.
Nafion/Polypyrrole Blends for Non Enzymatic Detection of Hydrogen Peroxide
Authors: Arena A. , Scandurra G. , Ciofi C. , Saitta G.
Published: March 2013

Mainly capacitive electrochemical devices have been developed by depositing ion conducting Nafion/Polypyrrole mixtures, onto the gap between gold and Multi Walled Carbon Nanotubes (MWCNTs) electrodes, applied on copier grade transparency sheets. The electrical properties of the MWCNTs/Nafion:Polypyrrole/Au devices are investigated by means of frequency dependent impedance measurements, and time domain electrical characterization. The results of current measurements performed in 0.1 M NaOH aqueous solutions, in response to triangular voltage inputs, show that the MWCNTs/Nafion:Polypyrrole/Au devices reversibly respond to the presence of H2O2, with a lower detection limit of about 5 μM.
Effect of Parasitic Capacitance on GMI Magnetic Sensor Performance
Authors: Saez Sebastien , Dufay Basile , Dolabdjian Christophe , Yelon Arthur , Ménard David
Published: March 2013

Magnetic sensors based on GMI devices are the subject of intensive research, as they appear promising for magnetometry applications. Performances of GMI magnetometers are often limited by the noise of the electronic setup. Thus, the present challenge is to increase the GMI device sensitivity (expressed in V/T) in order to decrease the equivalent magnetic noise of the system. In our previous work, we showed that the use of a pick-up coil in an off-diagonal configuration improves the magnetic sensor sensitivity and offers a promising approach for developing an inexpensive magnetometer with sub-pT/Hz equivalent magnetic noise levels. Ideally, the use of a coil increases the sensitivity linearly as a function of the number of turns. However, this effect is reduced by the parasitic capacitance of the coil. This affects the device sensitivity, noise level and system performance. The parasitic capacitance can degrade all of these, but also induces a resonance effect, which can help to optimize magnetometer sensitivity, and thus, its noise level. We analyze the effects of the parasitic capacitance on the system (sensitivity and noise) and propose optimization routes. We have obtained sensor sensitivity as high as 700 fT/Hz.
Different Kinds of Carbon-Based Material for Resistive Gas Sensing
Authors: Bořuta Roman , Olejnik Robert , Slobodian Petr , Riha Pavel
Published: March 2013

Gas sensing properties of networks made of carbon black, carbon nanofibers and carbon multi-walled carbon nanotubes are tested. The networks reaction to vapors of volatile organic compounds is measured through their change of electrical resistance. The measured resistance increase is up to 27.7 % for carbon black, 40% for carbon nanofibers and 47.7% for multi-walled carbon nanotubes.
Characterization of Rutile N-Doped TiO2 Films Prepared by RF Magnetron Sputtering
Authors: Dobromir Marius , Manole Alina Vasilica , Rebegea Simina , Apetrei Radu , Neagu Maria , Luca Dumitru
Published: March 2013

Rutile N-doped TiO2 thin films were grown by RF magnetron sputtering on amorphous and crystalline substrates at room temperature. The surface elemental analysis, investigated by X-ray photoelectron spectroscopy indicated that the nitrogen content of the films could be adjusted up to values as high as 4.1 at.%. As demonstrated by the X-ray diffraction data, the as-deposited films (100 200 nm thick) showed no detectable crystalline structure, while after successive annealing in air for one hour at 400°C, 500°C and 600°C, the (110) rutile peaks occurred gradually as dominant features. The rutile phase in the films was confirmed by the band gap values of the deposited materials, which stabilized at 3.1 eV, for the thin films having 200 nm thicknesses.
Discriminating among Acid-, Base-, and Salt-Based Electrolytes Using a Single Microfluidic Channel
Authors: Nemati Kianoosh , Hossein-Babaei Faramarz
Published: March 2013

The information obtained by monitoring the adsorption progress rates of ionic species in a liquid-filled microfluidic channel is used for their identification. The adsorption rates of three different analytes, HCl, KOH, and KCl, in a pure water-filled channel of microscale diameter are experimentally investigated by recording the temporal variation of the channel conductance. The electrolytes examined belong to the acid, base, and salt categories, respectively. Different temporal profiles are obtained for the electrical conductance of the channel. Each temporal profile was defined as a high dimensional vector which was mapped into a two dimensional feature space for categorization. It is shown that the extracted information from a conductance variation profile facilitates discrimination among HCl, KOH, and KCl solutions in distilled water regardless of their concentrations. The single channel device fabricated based on the presented concept is a low cost and disposable device which can be used for discrimination between acid, base, and salt electrolytes. The device can be utilized in electronic tongue applications.
Signal Processing Enhanced Fiber Vibration Sensors
Authors: Tosi Daniele , Olivero Massimo , Vallan Alberto , Perrone Guido
Published: March 2013

The paper analyzes the feasibility of cost-effective fiber sensors for the measurement of small vibrations, from low to medium-high frequencies, in which the complexity of the measurement is moved from expensive optics to cheap electronics without losing too much performance thanks to signal processing algorithms. Two optical approaches are considered: Bragg gratings in standard telecom fibers, which represent the most common type of commercial fiber sensors, and specifically developed sensors made with plastic optical fibers. In both cases, to keep the overall cost low, vibrations are converted into variations of the light intensity, although this makes the received signal more sensitive to noise. Then, adaptive filters and advanced spectral estimation techniques are used to mitigate noise and improve the sensitivity. Preliminary results have demonstrated that the combined effect of these techniques can yield to a signal-to-noise improvement of about 30 dB, bringing the proposed approaches to the level of the most performing sensors for the measurement of vibrations.
Migration of Atoms and Molecules through Organic Films, Modified by Laser Radiation
Authors: Turiev Anatolij M. , Butkhuzi Tengiz , Ramonova Aljona , Magkoev Tamerlan T. , Tsidaeva Natalia , Abaeva Viktorija , Tvauri I.V. , Khubezhov Soslan
Published: March 2013

In this paper we present an experimental study of migration of atoms and molecules of the substrate material in the thickness of the film in the direction of the surface by means of laser desorption mass spectrometry. The method is based on the time-of-flight principle of particle detection, desorbed from the sample surface by a laser pulse (LP) of nanosecond duration [. The main advantage of TOF mass spectrometer is that the registration of product desorption is carried out at the site of direct flight from the sample to the ion source, i. e. in the mass spectrum does not participate particle, reflected from the walls and other elements. In addition, the method allows to measure the time delay of the particles emission, relative to the exciting laser irradiation [.
Modeling of the Heat Loss in a Thermal Sensor for Water Made of NTC Thick Film Segmented Thermistors
Authors: Lukovic Miloljub D. , Nikolic Maria Vesna , Radojcic Branka M. , Aleksić Obrad S.
Published: March 2013

NTC thick film segmented thermistors were realized by screen printing of a low resistivity paste and conductive PdAg paste printed for electrodes. Two thick film thermistors as thermal sensors were placed in plastic tube housing connected to the water mains to form a calorimetric type of flow-meter, e.g. to measure the input water temperature and the thermistor self-heating temperature. Range constant voltage (RCV) was applied for self-heating thermistor power supply in different ranges of input water temperature. Modeling of the heat loss in the flow-meter for water was derived from heat balance equations for a self-heated thermistor in static water and in water flow conditions (static and dynamic thermistor temperature). Both temperatures (static and dynamic) were related to self-heating currents. The input water temperature was measured independently by a cold thermistor. Other parameters such as water thermal conductivity, thermistor exponential factor B and nominal thermistor resistance at room temperature were included in the thermistor heat balance equations. The logarithmic behavior of self-heating thermistors in the water flow enable modeling of heat loss as a function of static and dynamic currents related to static and dynamic thermistor temperatures. The model achieved was used in the fitting procedure of measured data of the flow-meter response.
Hydrogen-Induced Amorphization of Intermetallics and QED Coherence
Authors: del Giudice Emilio , Hison Cornelia , Germano Roberto , de Ninno A.
Published: March 2013

The mechanism of phase transition of some intermetallic (magnetic) alloys from a crystal state to an amorphous state on heating in hydrogen atmosphere, the so called hydrogen induced amorphization (HIA), is not completely elucidated. We propose an explanation of this phenomenon in the frame of Quantum Electro Dynamics (QED) formalism.
Signal-Processing Interface for Inductive Displacement Sensor
Authors: Brkic Miodrag , Djuric Snezana M. , Damnjanović Mirjana S. , Nagy László F.
Published: March 2013

In this paper, we present a signal processing interface for previously developed inductive displacement sensor, whose inductance is proportional to displacement of sensor elements. This measurement interface is based on measuring of root mean square (RMS) value of voltage on the sensor. This measurement method ensures good accuracy and high measurement rates of very small inductances, order of nH. A hardware realization of signal processing interface is described in details. Measurement results are presented and compared with values measured by impedance analyzer.
Temperature Dependence of Electrical Conductivity of Multi-Walled Carbon Nanotube Networks in a Polystyrene Composite
Authors: Petras David , Slobodian Petr , Olejnik Robert , Riha Pavel
Published: March 2013

The conductance properties of multi-walled carbon nanotube mats and their polystyrene composite were examined to investigate the mechanism of conduction and the specific role of the supporting polymer. By measuring the temperature dependence of the conductance, it was found that the conduction mechanism in carbon nanotube mat follows the series heterogeneous model when the conductance is described as the sum of metallic and barrier portions of the conduction path. This mechanism is affected by the polymeric portion of the composite, since the temperature dependence of the composite conductance is decreased.
Features of Optical Anisotropy of Terbium Iron Garnet
Authors: Tsidaeva Natalia , Abaeva Viktorija , Enaldieva Elena , Magkoev Tamerlan T. , Turiev Anatolij M. , Ramonova Aljona , Butkhuzi Tengiz
Published: March 2013

Rare earth iron garnets with narrow ferromagnetic resonance linewidths, very low hysteresis losses, and excellent dielectric properties have been widely applied in microwave devices in a wide range of frequencies (1100 GHz), magnetooptical transducers and typically employed as magnetic recording media [1-1. The rare earth iron garnets which can be described by chemical unit formula RE3Fe5O12 belong to cubic system with space group Ia3̄d, whose cell contains eight RE3Fe5O12 molecules and crystal lattice contains three crystallographic sites, dodecahedral site 24c {RE3+}, octahedral site 16a [Fe3+] and tetrahedral site 24d (Fe3+). The garnet in fact does not allow distortion to lower symmetry owing to its non-efficiently packed structure, which makes iron garnet structure become unstable with increasing rare earth ionic radius.
Using a Microwave Sensor as an Online Indicator of Neurological Impairment during Surgical Procedures
Authors: Goh Jung H. , Mason Alex , Field Mark , Browning Paul , Al-Shamma'a Ahmed
Published: March 2013

Lactate is known to be an indicator of neurological impairment during aortic aneurysm surgery. It is suggested that analysis of cerebrospinal fluid (CSF) removed during such surgery could provide useful information in this regard. Medical professionals find the prospect of online detection of such analytes exciting, as current practice is time consuming and leads to multiple invasive procedures. Advancing from the current laboratory based analysis techniques to online methods could provide the basis for improved treatment regimes, better quality of care, and enhanced resource efficiency within hospitals. Accordingly, this article considers the use of a low power microwave sensor to detect varying lactate concentrations. Microwave sensors provide a rapid non-invasive method of material analysis, which is robust, cost-effective, and has huge potential for a wide range of biomedical applications.
Novel Approach for Lysozyme Detection Employing Block Copolymer Overlayers on Plastic Optical Fibers
Authors: Athanasekos Loukas , Aspiotis Nikos , El Sachat Alexandros , Pispas Stergios , Riziotis Christos
Published: March 2013

A novel approach on lysozyme sensing is proposed by employing Polymer Optical Fibers functionalized successfully with overlayers of block copolymer sensitive materials. The detection scheme is based on electrostatic interaction between lysozyme and the copolymer. Low concentration levels of lysozyme have been detected successfully with almost spontaneous response times.
Entangled Network of Carbon Nanotubes Embedded in Polyurethane and its Use for Body Kinematics and Joint Flexion Sensing
Authors: Slobodian Petr , Riha Pavel , Saha Petr
Published: March 2013

Monitoring body kinematics and joint flexion has fundamental relevance in orthopedics and rehabilitation. The used sensing element is prepared from a highly-deformable polymer composite composed of a network of entangled electrically-conductive carbon nanotubes embedded in elastic polyurethane. The composite is prepared by an innovative procedure in which the non-woven polyurethane filtering membrane and the carbon nanotube cake are integrated by compression molding. As an example of the composite use as a strain sensor, human knee flexion and its cyclic movement is monitored, that may be applicable in athletic training as well as in orthopedics and rehabilitation.
The Role of Open Source Leadership in Developing High Technology Companies
Authors: Dimitrios Nasiopoulos K. , Sakas Damianos P. , Vlachos Dimitrios S.
Published: March 2013

The paper seeks to propose the concept of sustainable enterprise simulation models. The social, environmental and economic models are developed and simulated using iThink in the context of a high technology (high-tech) company. With the rapid growth of Social Networks [, Open source applications are increasingly invading the world of Web. High-tech companies must adapt to the world of open source, by the people who work in them, until their products. The paper has leveraged the systems dynamic paradigm to conduct sustainable enterprise modelling and iThink system to implement the models. It uses the design science research methodology for the proof of concept of the models and modelling processes. The models have been developed for a high-tech company and tested in the business settings. These models were finalised through a number of revisions and iterations of the design, develop, simulate, test and evaluate. While leaders have been around for thousands of years, we have attempted to show how the old rules of leadership [ are no longer helpful in dealing with the new games of the 21st century. In the high-tech companies we studied, we discovered patterns of leadership practice that not only yielded remarkable results, but also created a deep sense of meaning and identity for those involved.
The Contribution of Dynamic Simulation Model of Depiction of Knowledge, in the Leading Process of High Technology Companies
Authors: Dimitrios Nasiopoulos K. , Sakas Damianos P. , Vlachos Dimitrios S.
Published: March 2013

The purpose of this paper is to examine the impact of knowledge [ creation mode (e.g. goal-driven and goal-free) and organizational culture on knowledge creation and sharing performance in the context of high technology (high-tech) companies [ with the contribution of Dynamic Simulation Model. Both goal-free and goal-framed creation modes are more likely to support knowledge creation, while the goal-driven mode is not likely to be favorable for knowledge creation.
The paper has leveraged the systems dynamic paradigm to conduct sustainable enterprise modelling and iThink system to implement the models. High-tech companies who are frequently looking for new ideas for product design [ and manufacturing technologies [ are more likely to adopt the goal-free creation mode. High-tech companies who would like to emphasize goal achievement with respect to creation in manufacturing should form an organizational culture with a characteristic of market competition [. Also, a company with both goal-free and/or goal-framed creation modes is more likely to be willing to frame its strategic decisions (or goals) and then freely look for creative ways to reach the goals.
An Ultra Low-Power MR*1) Sensor for a Smart Water Meter or a Smart Gas Meter
Authors: Zhang Z. , Tsuchiya Y. , Akiyama O. , Konno H.
Published: March 2013

A new ultra low power MR sensor comprising MR elements integrated with Bi-CMOS IC chip, which is optimal for the use in smart water meters and gas meters playing important role in global smart gridization, has been developed. MR elements are configured as a Wheatstone bridge circuit. MR element patterns are placed in the perpendicular configurations as resistive components of the circuit. Those detect the magnetic field applied to X and Y axis respectively, and then outputs either high or low-level electric signal. Optimization of the MR element pattern aspect ratio (ratio of the element length to the element width) and configuration of the two-row parallel MR patterns in a longitudinal direction enable the equivalent current flow in the direction. This provides mutual magnetostatic coupling and cancellation of each demagnetizing field, and led to achieve minimizing the hysteresis of the resistance change rate affected by up and down of the applied magnetic field. Furthermore, this led to the improvement of mutual symmetry for both S to N and N to S direction of the magnetic field. This resulted in enhanced magnetic sensitivity and successfully obtained magnetic sensitivity higher than 0.8kA/m. For the power supply of the MR sensor, external intermittent control was adopted. Furthermore, active (on) time of the MR element was considerably shortened by utilizing the internal circuit of the IC. As a result, the sampling time was shortened to 1μs and the drive current of MR sensor was reduced to 0.3 μA.
*1)MR: Magneto-resistance
A Pressure Sensing Conductive Polymer Composite with Carbon Nanotubes for Biomechanical Applications
Authors: Lengálová Anežka , Slobodian Petr , Olejnik Robert , Riha Pavel
Published: March 2013

A sensing element made of conductive composite created by an entangled network of electrically conductive carbon nanotubes embedded in polyurethane was used for simultaneous measurements of the pressure between the shoe and floor as well as the extension of the leg at the knee joint during marching. The results recorded as sensor resistance change show reasonable reversibility of the basic sensor characteristics, which gives potential for practical applications.
Microwave Technology: The Missing Piece of the Puzzle
Authors: Korostynska Olga , Mason Alex , Al-Shamma'a Ahmed
Published: March 2013

At present, water quality control is still dominated by laboratory analysis of grab samples. Sensors are only available for a very limited number of parameters and frequently do not entirely meet the needs of the users. Even a brief overview of the state-of-the-art in the real time water monitoring reveals that it is not possible to achieve adequate detection of water parameters by using only one type of sensor. Accordingly, the solution is to merge various technologies into a single system that would employ the best available methods for the detection of specific water contaminants, so as to provide overall superior sensitivity, selectivity and long-term stability, while enabling real-time wireless data collection for enhanced cost-effectiveness. Namely, multi-sensor platforms that utilise the best available methods combined into a single monitoring process are seen as the only way to achieve the holistic monitoring capabilities. It is suggested that a special role in this development is reserved for microwave technology based sensors a missing piece in the puzzle to potentially solve the issue of real-time water quality control. This paper reviews the capabilities of microwave sensors for real-time water quality monitoring as compared to other alternative methods, namely standard UV-VIS optical methods; fibre optic sensors; amperometric sensors, biosensors, specifically-sensitive microelectrodes and lab-on-chip sensing systems.
The Effect of Oxygen Molecule Adsorption on Structural and Electrical Properties of (8, 0) Carbon Nanotube: A Density Functional Study
Authors: Horastani Zahra Karami , Hashemifar S. Javad , Sayedi S. Masoud , Sheikhi Mohammad Hossein , Alaei Reza
Published: March 2013

By using spin polarized density functional calculations, we investigate the effect of oxygen molecule adsorption on the structural and electrical properties of (8, 0) single wall carbon nanotube. The obtained results indicate endothermic chemisorption of O2 on the nanotube surface with a large binding energy of about 598 meV and a significant charge transfer of about 0.43 e- per molecule. We find that despite the triplet ground state configuration of free oxygen molecule, adsorbed oxygen on the nanotube prefers a zero moment spin singlet state. It is discussed that O2 chemisorption dopes the (8, 0) carbon nanotube with hole carries and thus increases its work function from 4.34 to 4.89eV. This hole doping effect may show potential applications of carbon nanotubes in conductivity and thermopower electric based sensors.
Low-Temperature Synthesis of Maghemite Nanoparticles
Authors: Kartswnakis Ioannis , Papadopoulos N. , Tserotas P. , Švec P.
Published: March 2013

Recently, the preparation of magnetic iron oxide nanoparticles has been thoroughly studied due to their unique electric and magnetic properties. Magnetic nanoparticles find uses in a wide range of applications, from data storage and sensors to medical imaging and cancer treatment. Herein, we report a fast and economic chemical procedure for the growth of monodispersed maghemite nanoparticles (NPs) from iron pentacarbonyl Fe (CO)5. The reaction takes place in a closed vessel where the oxidation strength of dimethylsulfoxide (DMSO) is limited by the reductive strength of liberated carbon monoxide from the initial complex. DMSO strips metallic Fe from the intermediate organometallic precursors (e.g. Fe2(CO)9, Fe3(CO)12), which form at temperatures above 100 °C, while at the same time oxidizes it in a controlled manner to the desired magnetic phase at temperatures as low as 130 OC, without the need for the classical refluxing step. Oleic acid is also used as a surfactant, thus maintaining a narrow size distribution of NPs. Another advantage of the synthetic route is the short reaction time (30 min).
Parameters Consideration in Designing a Magnetorheological Damper
Authors: Yazid Izyan Iryani Mohd , Mazlan Saiful Amri , Zamzuri Hairi , Mughni M.J. , Chuprat S.
Published: March 2013

This paper presents a simulation study of electromagnetic circuit design for a mixed mode Magnetorheological (MR) damper. The magnetic field generated by electromagnetic circuit of the MR damper was simulated using Finite Element Method Magnetics (FEMM) software package. All aspects of geometry parameters were considered and adjusted efficiently in order to obtain the best MR damper performance. Eventually, six different parameters approach were proposed; the selection of materials, the polarity of coils, the diameter of piston, piston rod and core, the shear and squeeze gaps clearance, the piston pole length and the thickness of housing.
Leaky Interface Waves Optical Detection at Solid-Solid Interface
Authors: Han Qing Bang , Wang Hao , Li Jian , Zhu Chang Ping
Published: March 2013

The experimental investigation on transparent solid/solid (Aluminum and Plexiglas) interface leaky waves generated by a pulse laser and detected with a photo elastic effect technique is reported. Three waves Lateral wave, Leaky Rayleigh (LR) wave and Leaky Interface wave (IW) are detected successfully; The velocity of the detected interface wave is in good agreement with theoretical calculation and the attenuation characteristic of the two Leaky waves is also in accordance with the theoretical prediction. The Leaky waves propagate along the weak bonding interface is also measured, it was found with the continue Epoxy solidifying, the wave amplitude gradually decrease and the two Leaky waves are more difficult to distinguish. The successful measurement should improve the scientific and technological potential for the research of solid/solid interface waves.
Microfabrication (Hot-Embossing) of COC Microfluidic Devices: Effect of Norbornene Content on Replication Fidelity and Surface Modification by UV-Photografting
Authors: Jena Rajeeb Kumar , Yue Chee Yoon
Published: March 2013

The fabrication of polymer based microfluidic devices using the hot embossing technique and their surface modification for easy fluid flow through the devices has been a growing field of research. During hot embossing, the replication fidelity on polymer substrate not only depends on the processing parameters such as temperature, pressure and time but also on their chemical structure which affects their thermo-dependent viscoelastic properties. For copolymers such as cyclic olefin copolymer (COC) which comprises ethylene and norbornene units, such properties depend on their relative ethylene and norbornene content. We report in this paper, a systematic study of replication fidelity and surface modification on COC polymer with varying norbornene content from 65 to 82 wt%. Replication fidelity which includes the surface morphology and cross-section profiles of the microchannel were characterized using SEM and Confocal microscope respectively. The modified surface was evaluated using Fourier transform infrared spectroscopy (FTIR spectroscopy) and water contact angle measurement. It was observed that in hot embossing, higher norbornene content contributed to good replication fidelity at identical experimental conditions. Furthermore, it was observed that with increase in norbornene content, the grafting efficiency decreases resulting in poor surface modification.
Flexible Approach to Sensors Arrays Nanopatterning for Real-Time Water Contaminants Monitoring Platform
Authors: Korostynska Olga , Yan Jun Jie , Mason Alex , Arshak Khalil , Al-Shamma'a Ahmed
Published: March 2013

This paper reports on the development of a flexible nanopatterning approach using the NanoeNablerTM to manufacture miniaturised sensor arrays platform for real-time water quality assessment. Traditionally biosensors are fabricated by lithography, screen printing, inkjet printing, spin-or deep-coating methods to immobilize the sensing element onto substrate pre-patterned with electrodes. NanoeNablerTM patterning method is benchmarked against other currently adapted approaches for cost-effective sensors arrays manufacture. Sensors measuring ~1 µm diameter or more can be patterned for further employment in molecularly imprinted polymer structures. Notably, the dimensions of the sensor depend on the fluid being patterned and on the interaction forces between the substrate and the patterning tool. Thus, careful selecting of patterning parameters is vital for repeatable and controlled manufacture of sensors to guarantee superior sensitivity. The reported nanopatterning method is capable of accurately placing attoliter to femtoliter volumes of liquids, including proteins and DNAs, onto any substrate, thus making it an ideal technology for biomedical sensors. A custom-made 1 cm2 silicon wafer with 48 interdigited electrodes sensor heads was used as a platform for the multi-sensor array with potential use in a wide range of real-time monitoring applications.
Sensing Uric Acid with Bimetallic Nano Ag-Pt Particles
Authors: Karthikeyan Balakrishnan , Murugavelu Marimuthu
Published: March 2013

The emergence of nanoparticles (NPs) has opened new opportunities in analytical chemistry [. These NPs exhibit different properties and functionalities when compared to monometallic particles. In particular, they show enhanced selectivity and reactivity when used as catalysts and sensors [2-. The NPs have large surface area, high surface free energy, good biocompatibility and suitability, and it has been used in constructing electrochemical biosensors [7, . The fascinating physical and chemical properties of NPs offer excellent prospects for a wide range of bio sensing applications [ . Uric acid (UA) is the principal final product of purine metabolism in the human body [1. It has been shown that extreme abnormalities of UA levels are symptoms of several diseases (e.g. gout, hyper uricaemia and LeschNyhan syndrome)[11,1 .In general, electro active UA can be irreversibly oxidized in aqueous solution and the major product is allantoin [1. In continuation of our interest with the bimetal nanoparticle (BNP) sensing here in this study, we employed Ag/Pt BNPs for detecting of UA.
Preparation of the Sulfur-Free Expanded Graphite Using Induction Heating Method
Authors: Wang Zhen Ting , Wang Yang
Published: March 2013

The sulfur-free expansible graphite and expanded graphite were prepared by induction heating method at different temperature using natural flake graphite, nitric acid and phosphoric acid as the raw materials. Expansion effect and heating mechanism has been analyzed. The microstructure of expansible graphite and expanded graphite has been analyzed by means of a scanning electron microscope and an energy spectrum analyzer. The result shows that the expanded volume of the expansible graphite can reach 200mL/g. Expanded graphite is characterized by vermicular structure and more developed pore structure where the pore of internal level basically maintains the original layer appearance of natural flake graphite.
Influence of Bentonite on Properties of Glass-Based-Sintering Material for Borehole-Wall Renovation
Authors: Yang Chun , Li Zhi Jun , Liu Bao Lin
Published: March 2013

Borehole-wall collapse mostly occurs in fractured-rock layers during geological and oil drilling. Steel-casing installation，though with high cost and low efficiency，is currently one of the most fundamental methods for mending broken bore-hole walls. Manufactured casing formed by hot melting，however，provides us an alternative. In order to enhance its qualities，like strength and the capacity of resisting corrosion，of the material，we added bentonite as additive to explore some certain links between properties such as density，porosity, abrasion resistance and different sintering temperatures as well as soaking time.
Measurement and Characterization of the Particle Size of Refractory Corundum
Authors: Yang Fen Rong , Liu Kai Qi , Wang Bing Jun , Xie Xiao Hu
Published: March 2013

With introducing briefly the refractory powder materials, the article analyzed the morphology and particle size distribution of commercial different size fraction corundum powder by scanning electron microscopy and laser particle size analyzer. The results showed that most of corundum powder particles were angular spherical, Their particle volume average diameters D(4,3) are greater than median grain sizes D50, and with the difference increasing the distribution curve symmetry becomes worse. Moreover, size frequency distribution curve presents slanting unimodal or bimodal pattern, not completely normal distribution. Besides those, particle size ranges are very wide, e.g. the D90 of 15 μ m is 30 times larger than D10. Therefore, using only the average particle diameter indicates the powder is not comprehensive. The parameters and the size distribution cure measured by laser particle size analyzer can be detailed and accurate to reflect actual powder particle size and distribution, so using them as the commercial corundum powder specification values will be important to enhance the effective utilization of the powder.
Synthesis and Characterization of FeO+ Nanosheets
Authors: Guo Jun , Li Cai Xia , Zhang Lin , Xia Jin Feng , Jiang Danyu , Li Qiang
Published: March 2013

The layered FeOCl has been synthesized from Fe2O3 and FeCl3 by chemical vapor transport technique at 380°C., and an intercalation of sodium benzoate into as-synthesized FeOCl was conduct. After the intercalation composites were sonicated for 4 h in butyl alcohol, the colloidal suspension of layered iron oxide nanosheets was obtained. The FeOCl and the intercalation composites were analyzed by powder X-ray diffraction (XRD). Transmission Electron Microscopy (TEM) was also used to characterize the morphologies of the FeO+ Nanosheets. Except to this, the selected area electron diffraction was also performed to examine the iron nanosheets.
The Influence of Alumina Addition on the Microstructures of YSZ
Authors: Meng Zhao Qiang , Jiang Dang Yu
Published: March 2013

It is well known that the martensitic transformation of YSZ from the metastable tetragonal phase (T-phase) to the monoclinic phase (M-Phase) is accelerated in hot water (especially at 473K). Trace quantities of alumina are known to aid densification, and is also exceptionally resistant to low-temperature degradation (LTD). The current contribution describes a detailed electron microscopy investigation to determine the location of trace quantities of Al2O3 in a YSZ.
Interfacial Reactions between Polymer Derived SiC Fiber and Ti3Si(Al)C2
Authors: Zhang Jun Wei , Hu Chun Feng , Wang Yu Gang , Huang Qing , Cui Ping
Published: March 2013

In this paper, interfacial reactions between polymer derived SiC fiber and Ti3Si(Al)C2were analyzed. Strong interfacial reactions occurred in 20 vol.% SiCf/Ti3Si(Al)C2composite during the vacuum spark plasma sintering at 1350 °C. At the begining, the Ti3Si(Al)C2suffered spontaneous decomposition and resulted in the sublimation of gaseous Ti, Si and Al, and de-intercalation of TiC from the crystal structure, when it was combined with SiC fiber during sintering. Then, Ti reacted with the SiC phase and turbostratic graphite in the fiber and TiC was formed, and also Al was oxidized into Al2O3. Meanwhile, most of gaseous Si released from Ti3Si(Al)C2escaped from the outer surfaces of the composite under the compressive stress of 30 MPa and the vacuum environment, the rest Si was cooled into solid state following gas-solid reaction mechanism.
Effect of Nb2O5/La2O3 Additions on Mechanical Properties of Al2O3 Ceramics Prepared by Microwave Sintering
Authors: Ai Yun Long , Jiang Nan , He Fei , Liang Bing Liang , He Wen
Published: March 2013

The influence of Nb2O5 and La2O3 on the phase and microstructure evaluation and mechanical properties of composite ceramics sintered with 2.45 GHz microwave energy was investigated. The results showed that Nb2O5 could densify the pure alumina with a lower sintering temperature and a short sintering time. Nb2O5 reacted with Al2O3 to form AlNbO4 completely and the amount of AlNbO4 increased with the increasing content of Nb2O5, distributing at the Al2O3 grain boundaries. The specimen doped with 10 Vol.% Nb2O5 sintered at 1500 °C exhibited plenty of columnar grains with draw ratio about 1:3. La2O3 reacted with Al2O3 to form LaAl11O18 completely, the specimen doped with 10 Vol.% and 15 Vol.% La2O3 sintered at 1500 °C exhibited plenty of columnar grains with draw ratio about 1:4. The existence of columnar grains enhanced the microhardness and fracture toughness of composite ceramics.