bluuebunny/crossref_metadata_2025 huggingface dataset:
Mobile Robot Diagnosis with Bayesian Filters
Authors: Zając Michał , Uciński Dariusz , Stetter Ralf
Published: March 2009

In the following paper we consider a problem of fault detection for a mobile robot. The robot which our work is related to, is based on a new type of the steering principle [1]. The crucial part of the steering system are axle position sensors. A failure of one of them might result in an interruption of operation and/or serious damages to hardware and environment elements. To avoid the risk of such events, a reliable fault detection system has to be implemented. Fault detection is facilitated by incorporating measurements from various sensors located on board of the robot (incremental encoders, absolute encoders, sonar, cameras, compass, GPS). In our work we consider the Bayesian approach (Kalman filter [2,3] and particle filters [4,5,6]) to create a diagnostic system of the robot. Due to the limited resources of the computing unit it is necessary to strongly optimize the efficiency of applied algorithms. In our work we plan to perform simulations to find the best suited algorithm for our vehicle. Accordingly, we build a numerical tool in MATLAB to simulate mobile robot navigation and fault diagnosis tasks. We also present the construction of our robot and explain how a reliable fault detection system is important for the proper functioning and safety of the mobile robot. We introduce the fault detection algorithms which we plan to apply in the described hardware solution. At the end, we summarize our work and provide an outlook on our future research plans.
Operating Degradations of Air Turbine Scoops of Turbo-Engines
Authors: Szczepankowski Andrzej , Szymczak Janusz , Spychała Jaroslaw
Published: March 2009

The paper presents various types of turbine scoops damages that are being found in the operating process of air turbine engines (TSO). When dividing them, having in mind a genesis of their origin, a special attention has been paid to corrosion and high-temperature erosion, often being a reason for destruction of the entire unit.
The damages hereto described have been illustrated with examples collected during endoscope surveys of TSO internal spaces or their post-failure disassembly. The summary points out to the ways and directions of works aiming at early detection of TSO turbines units damages, and thus at improvement of their operating safety.
Turbine Engine Health/Maintenance Status Monitoring with Use of Phase-Discrete Method of Blade Vibration Monitoring
Authors: Witoś Miroslaw , Szczepanik Ryszard
Published: March 2009

The intended aim of the paper was to present a short review of more than 15 years of experience of ITWL in the field of applying the signal of actual rotational speed (aperiodic and oscillation components thereof) to the expert diagnosing of aero-engines, including identification of low- and high-cycle fatigue (LCF, HCF) of critical structural members. What has been presented is some essential metrological bearings of the non-contact technique of measuring the engine’s rpm with some flexible key phasors (i.e. vibrating compressor/turbine blades). Also, methods of numerical analysis of measuring signals, in use nowadays, have been discussed. With the jet engine of the SO-3 type (in use on the TS-11 “Iskra” combat trainer) as an example, are discussed algorithms of both the identification of disadvantageous aeromechanical effects (energy state of the engine - i.e. the source of accelerated HCF wear of structural components) and the early detection of symptoms of fatigue failures to compressor blades and the bearing system. The discussed problems have been illustrated with examples selected as to emphasise practicalities of applying a new source of diagnostic information to ‘actively’ control the process of fatigue wear (HCF + LCF) of engine components and to forecast the engine health/maintenance status.
Load Carrying Capacity of Microbearings with Parabolic Journal
Authors: Wierzcholski Krzysztof , Miszczak Andrzej
Published: March 2009

This paper presents the load carrying capacity (load capacity) and friction coefficient calculation of hydrodynamic HDD micro-bearing with parabolic profile of journal. One of the reason of such journal profile is that this journal profile contributes to the variation (an increase or decrease) the memory capacity of HDD drive operating on hydrodynamic micro-bearings. Such properties are very important and required in HDD micro-bearings.
Up to now, the dynamic behavior of HDD spindle system with fluid micro-bearings was considered by Jang at al. [3]. They simulated an increase in the memory capacity by increase in the bearing width and by application herringbone or spiral grooves on the sleeve and journal surfaces of HDD micro-bearings.
A Model-Less Method for Added Mass Identification
Authors: Suwała Grzegorz , Jankowski Łukasz
Published: March 2009

This paper present and validates experimentally a model-less methodology for off-line identification of modifications of nodal masses. The proposed approach is entirely based on experimentally measured data; hence no numerical modeling and tedious fine-tuning of the model are necessary. The influence of the added mass is modeled using virtual distortion forces and experimentally obtained system transfer matrices. The identification amounts to solving an optimization problem of minimizing the mean square distance between measured and modeled structural responses, the latter is based on previously recorded responses of the unaffected structure.
Application of Optical Flow and Methods of Group Lee Representation in Problems of Detecting of Movements and Pattern Detection on the Images
Authors: Makarychev V.P.
Published: March 2009

The methods of image processing for problems of detection and the analysis of movements and detection of concrete objects moving in video surveillance systems and other applications are considered. The field of speeds received by means of optical streams allows to analyze complex situations with which does not consult classical difference method, for example, the analysis of movement in crowd, or allocation of the person on strong disturbance images. The field of speeds is broken on cluster which allocate separate elements in complex area. For the detection on the personnel of objects is proposed the method, based on the theory of the ideas of continuous groups, which makes it possible to carry out a Fourier analysis relative to special functions, in the best way fitted out for the specific transformation groups, for example, group of the motions of plane. The analogs of the theorem about the roll and of the properties of Fourier transform make it possible instead of the labor-consuming correlation method to manage with the calculation of the pair of integrals.
Decomposition of Non-Stationary Signals Based on the Cochlea Function Principle
Authors: Dusek Daniel
Published: March 2009

This paper deal with possibility of cochlea function principle utilization for decomposition any non-stationary signals. The mathematical model based on array of resonators is described in this paper. This array of resonators is actuated by non-stationary signal, which is compound from different frequency components. Spectrograms calculated for different values of resonators viscous damping are results of this work and this results are also compared with spectrogram obtained from Short Time Fourier Transformation (STFT).
Human Gait Analysis and Classification Based on Neural Networks and Fuzzy Logic
Authors: Pauk Jolanta , Derlatka Marcin , Długosz Rafał , Kolasa Marta
Published: March 2009

Human gait analysis and classification is the process of identifying individuals by their walking manners. Computerized gait analysis using neural networks and fuzzy logic has become an integral part of the treatment decision-making process. Authors proposed the integration of kinetic data, more specifically power joints in combination with neural networks and fuzzy logic. It is a relatively new addition to other types of data including temporal and stride parameters. The performance of our approach was verified in laboratory for motion analysis. The obtained results are satisfying.
Mechatronics Engineering on the Example of a Multipurpose Mobile Robot
Authors: Stania Marek , Stetter Ralf
Published: March 2009

This paper presents the patented mechanical concept for steering and level control of a mobile robot equipped with four driving units and the methods that lead to the development of this mechatronic system. The mobile robot exhibits excellent maneuverability and considerable advantages when moving in difficult environments such as rough landscapes. The paper discusses a refined approach to develop mechatronic systems which is based on the well-known V-model. The refined approach allows a conscious planning and control of a mechatronic design process.
Contour Representation by Clustering Curvatures of the 3D Objects
Authors: Lipnickas Arūnas , Raudonis Vidas
Published: March 2009

The purpose of this work is to segment large size triangulated surfaces and the contours extraction of the 3D object by the use of the object curvature value. The curvatures values allow categorizing the type of the local surface of the 3D object. In present work the curvature was estimated for the free-form surfaces obtained by the 3D range scanner. A free-form surface is the surface such that the surface normal is defined and continuous everywhere, except at sharp corners and edges [2, 5]. Two types of distance measurements functions based on Euclidian distance, bounded box and topology of surface were used for the curvature estimation. Clustering technique has been involved to cluster the values of the curvature for 3D object contour representation. The described technique was applied to the 3D objects with free-form surfaces such as the human foot and cube.
Electrical Measurements and Analyses with Data Acquisition Devices (DAS) of Heating and Cooling Capacities of the Intercity Coaches
Authors: Yılmaz Özgür , Erçetin Reşit , Çetin Akıncı T. , Ersoy Sezgin
Published: March 2009

Predominantly coaches are preferred for intercity passenger transportation in our country. Vehicles are supposed to meet the passengers’ expectations in terms of safety, comfort and health during journey. Some features such as an internal environment that has an adequate and balanced temperature level is one of the essentials of the features affecting passenger comfort directly. To provide these, various coach manufacturer firms are continuing to make many trials and test studies at design stage. For that purpose, the vehicle-heating and cooling capacities of the intercity coaches were analyzed and examined in the scope of this study, by means of the thermometers and data acquisition systems (DAS). The thermal measurements related the subject were made on the intercity coaches at the Development & Test Center of a intercity coaches producer firm. The measurement results obtained from the experimental studies were examined and in consequence of the assessment of these data, implementation of the optimum resolutions was recommended in terms of passenger health and comfort.
Line Scale Calibration in Non-Ideal Measurement Situation
Authors: Kausinis Saulius , Kasparaitis Albinas , Barakauskas A. , Barauskas Rimantas , Jakstas Aurimas , Kilikevičius Artūras
Published: March 2009

The precision line scale calibration in dynamical mode of operation is considered. A new interferometer-controlled comparator with moving microscope has been developed and optimised in order to reduce both the measurement uncertainty and calibration process duration.
Modal analysis performed and measurements conducted of the spatial vibrations of comparator structure revealed that dynamically-induced errors can noticeably contribute to the measurement uncertainty budget. They can be prominently reduced, in particular, by proper improvement and optimisation of the carriage structure and elimination of the dry friction in the carriage drive.
Precision Measurement of the Carriage Vibrations at the Different Speeds
Authors: Kilikevičius Artūras , Vekteris Vladas , Kasparaitis Albinas
Published: March 2009

Dependence of a comparator reading dynamic error on vibro activity of a carriage is analyzed in the paper. There is shown how change reading errors at action only carriage drive vibrations and at artificially provoked carriage vibrations at different frequencies. Results achieved enable to evaluate the influence of vibration components on reading errors.
Hardware Structure of a Control Section of Manipulation Mechanism for Acoustical Measurement in Anechoic Chamber
Authors: Mężyk Jordan , Kamisiński Tadeusz , Zbrowski Andrzej , Flach Artur
Published: March 2009

The paper presents the structure of control section of measurement manipulator for acoustical tests in anechoic chamber. The specific of that kind of measurements brings up the need of measurement microphone positioning in many points of the measurement space accordingly to relevant standards. In most cases during the tests it is necessary to position the microphone in certain points on the hemisphere. The paper presents hardware structure and software to control the measurement manipulator accordingly to a specified algorithm. A modular construction of manipulator was chosen, which is composed of industrial turntable and two linear motion modules. That solution means that the device under test fixed on the turntable rotates in the range of 2π, and the measurement microphone moves on the track of one quarter of a circle.
Rowing Force and its Simulation on Training Facility
Authors: Grigas Vytautas , Domeika Aurelijus , Legha Alexandra , Satkunskiene Danguole , Toločka Rymantas Tadas
Published: March 2009

The paper presents results of experimental measurements of the parameters of rowing process when rowing in a river, on the pool-type training facility and on “Concept II” rowing machine. The comparison of results of measurements showed the significant difference of rowing force generated by rowing in the machine and in the boat, thus the novel training facility is proposed having the hydrodynamic loading unit equipped with proportional flow control valve controlled by computer evaluating parameters of rowing, which is able to ensure loading on the oars more adequate to the real rowing conditions.
Study of the Effect of Process Induced Uncertainties on the Performance of a Micro-Comb Resonator
Authors: Codreanu Irina , Martowicz Adam , Gallina A. , Pieczonka Łukasz , Uhl Tadeusz
Published: March 2009

This paper presents a modeling technique based on the integration in the classic deterministic simulation methods of probabilistic computational techniques such as uncertainty analysis and sensitivity analysis. As study case, it is presented a micro-comb resonator that is actuated electrostatically to vibrate in the plane parallel to the substrate. A deterministic Finite Element coupled electromechanical analysis is performed to evaluate the mode shapes and the corresponding eigenfrequencies of the mobile mass and afterwards a Monte Carlo simulation is used to determine the dispersion of the eigenfrequency of the mode shape of interest in function of the variations of the input parameters. The scatter of the results is analyzed and then it is presented a sensitivity analysis for establishing which of the input parameters have more influence on the variability of the microresonators performance.
Mechanical Properties of G17CrMoV5 – 10 Cast Steel after Regenerative Heat Treatment
Authors: Golański Grzegorz
Published: March 2009

The paper presents results of research on the influence of regenerative heat treatment on structure and properties of G17CrMoV5 – 10 cast steel. Investigated material was taken out from a turbine frame serviced for over 250 000 hours (total service time) at the temperature of 535 oC. The cast steel after service revealed degraded bainitic-ferritic structure and was characterized by mechanical properties ranging below norm requirements. It has been proved that high tempering temperature in the case of cast steel with bainitic structure ensures optimum combination of mechanical properties and impact energy. It has also been shown that ferrite has a negative influence on impact energy of the cast steel with bainitic-ferritic structure.
Stability of a-C:N:H Layers Deposited by RF Plasma Enhanced CVD
Authors: Jonas Stanisława , Kyzioł Karol , Lis Jerzy , Tkacz-Śmiech Katarzyna
Published: March 2009

A series of amorphous hydrogenated carbon layers doped with nitrogen (a-C:N:H) was deposited on Si (001). The synthesis was performed from gaseous N2/CH4 mixture using PE CVD (RF CVD technique; 13,56 MHz). An influence of the processing conditions on layer-growth rate was analysed. Thickness of the layers deposited during 1 hour at various temperatures, pressures and RF powers were taken as a basis. It has been proved that the substrate temperature is a key parameter for the layer formation. Temperature rise results in the deposition rate decrease. This unfavourable effect may be reduced by application of increased gas pressure and/or higher plasma RF generator power. At optimal conditions (46 oC; 0,8 Tr; 60 W) the deposition rate reaches up to 600 nm/hour.
FT-IR spectra of the layers were measured within 1250 - 4000 cm-1 and discussed with regard to the atomic structure. The intensities of the characteristic absorption bands were compared. The results show that the layers have various N/C ratios according to the applied processing conditions.
An Investigation on the Solid State Reduction of Chromite Concentrate
Authors: Atasoy Ahmet , Sale F.R.
Published: March 2009

In this article, Turkish chromite concentrate was reduced with metallurgical coke at temperature between 1000-1500 °C with variables reducing times. The reduction mechanism and the microstructure of the reduced chromite were investigated. There were closer relationships between the reduction of chromite and the sample morphology, such as, the surface area and the porosities and cracks of the particle have positive effect on the metallization of iron and chromium oxides. The reduction of the iron chromite spinel started at 1000 °C, but picrochromite started to reduce at temperature around 1300 °C. At lower temperature, the formation of iron carbide phases was affected on the formation of ferro alloy and accelerates the reduction of chromium. The formation of carbon monoxide was also affected on the reduction of chromite spinel, especially around imperfections of grain where porosity, cracks and fractures act as diffusion channel for the reducing gas. For the charecterisation of the reaction products, X-ray diffraction techniques, SEM and EDAX were used.
Dynamic Chip Breaker Design for Nickel-Base, Inconel 718, Alloy with Coated Carbide Tools Using Negative Angle Tool Holder
Authors: Karabulut Şener , Güllü Abdulkadir
Published: March 2009

This study has focused on the chip-breaker design and experimental cutting of Inconel 718with the designed chip breaker. The process of chip breakage for Inconel 718 with respect to cutting speed, depth of cut and feed rate then chips and machined surfaces were analyzed from the experimental results. For this purpose, the nickel-base super alloy, Inconel 718was machined with a two layers PVD coated (TiAlN-TiN) carbide insert at feed rates of 0.10, 0.15, 0.20, 0.30 mm/rev, 0.5, 1, 1.5, 2 mm with depth of cuts, and 30, 45, 60, 75m/min cutting speeds using developed dynamic chip breaker with Negative tool holders in dry cutting conditions. Chip pictures and surface roughness (Ra) were recorded. Chip breakability during machining of the Inconel 718 depends on DC motor speed and chip breaker position on the cutting tool. The experimental results show that the designed chip breaker can break long chips at any cutting condition and acceptable surface finish can be achieved. In addition to this, according to cutting conditions, the usage of dynamic chip breaker on the surface of cutting insert is measured between 1% and 40% cooling effects using negative tool holder.
Investigations of Mixed and Submandibular/Sublingual Saliva
Authors: Andrysewicz Edyta , Dąbrowski Jan Ryszard , Leonow Grzegorz
Published: March 2009

The paper presents investigation results of the rheological and some physico-chemical properties of mixed and submandibular/sublingual saliva (both unstimulated). Samples were collected in accordance with a predetermined methodology in order to eliminate the influence of such factors as, for example, time elapsed since the last meal. The initial analysis of human saliva showed a considerable divergence of the studied physico-chemical and rheological parameters. It was found that the submandibular/sublingual saliva constitutes a better diagnostic basis than the mixed saliva.
Modeling of an Adaptive Beam with MR Fluid
Authors: Sapiński Bogdan , Snamina Jacek
Published: March 2009

This paper is devoted to modeling of a three-layered cantilever beam filled with magnetorheological (MR) fluid. The beam consists of two aluminium outer layers and an MR fluid layer placed between them. The study covers description of MR fluid behavior in the pre-yield regime, analysis of strain and internal forces, formulation of differential equations of motion and finite element model (FEM) and numerical calculations. The aim of the study is to determine maximal amplitudes up to which the MR fluid operates in the pre-yield regime.
Neural Network – Backstepping Control for Vibration Reduction in a Magnetorheological Suspension System
Authors: Zapateiro Mauricio , Luo Ning Su , Harimi Hamid Reza
Published: March 2009

In this paper we address the design of the controller for semi-active vehicle suspension system that employs an MR damper as the actuator. MR dampers are nonlinear devices which are difficult to model. Several MR damper forward models have been proposed; they can estimate the damping force of the device taking variables such as control voltage and velocity inputs. However, the inverse model, i.e., the model that computes the control variable is even more difficult to find due to the numerical complexity that implies the inverse of the nonlinear forward model. In our case, we develop a neural network able to reproduce such inverse dynamics. This neural network is connected to a backstepping controller that estimates the damping force to reduce the vibrations of the system. The performance of the controller is evaluated by means of simulations in MATLAB/Simulink.
Intelligent Live Environment Design with Assistive Robots for Vulnerable Persons
Authors: Stoian Viorel , Nitulescu Mircea , Pana Cristina
Published: March 2009

We present in this paper several ideas about the usability of the robotic arms and mobile robots as an assistive technology in a smart house where people with disabilities daily live. First, psychological and social aspects of smart home technology are presented and after that the modularity and standardization processes are discussed. Next we propose a smart house plan, equipped with a mobile robot which has a manipulator arm. This robotic system is used to help vulnerable persons, the handicapped men vehicle seat being equipped with a robotic arm which can manipulate objects by a hyper-redundant gripper. For the control of the processes in the smart house, we propose a hierarchical control system and for the mobile robot we use the artificial potential field method. Also, this paper points out the edutainment concept (EDUcation and enterTAINMENT) by robotics. Finally, some applications are presented.
Structural and Magnetic Transitions in Rapidly Solidified Heusler Alloys Ribbons
Authors: Suñol Joan Josep , Saurina J. , Varga Rastislav , Hernando B. , Sánchez Llamazares José Luis , Santos J.D. , Prida V.M.
Published: March 2009

The most extensively studied Heusler alloys are those based on the Ni-Mn-Ga system. However, to overcome the high cost of Gallium and the usually low martensitic transformation temperature, the search for Ga-free alloys has been recently attempted, particularly, by introducing In, Sn or Sb. In this work, Mn50Ni40In10, Mn50Ni34In16, Ni50Mn36-xIn14+x (x = 0, 0.5, 1, 1.5) and Ni50Mn37Sn13 ribbons has been obtained by melt spinning. We outline their structural and thermomagnetic behavior. Columnar grains and preferential orientation has been obtained. The martensitic, Tm, and the Curie, TC, temperatures of the ribbons are lower than those of the bulk samples with similar compositions. This effect is probably due to the ribbons small and constrained grains. For it, a large under-cooling is necessary for the martensitic transformation. The decrease of TC in the ribbons could be associated with the increased degree of quenched-in short-range disorder around defects.
Displacive Phase Transformations
Authors: Paidar Václav , Ostapovets Andriy
Published: March 2009

Shear deformation and shuffling of atomic planes are elementary mechanisms of collective atomic motion that take place during displacive phase transformations. General displacements of atomic planes are examined, i.e. -surface type calculations extensively used for the stacking faults and crystal dislocations are applied to single plane shuffling and alternate shuffling of every other atomic plane producing in combination with homogeneous deformation the hcp structure (martensitic type) from the initial bcc structure (austenitic type). Similar approach considering shear type planar displacements leads to the Zener path between the bcc and fcc lattices. The effect of additional deformation required to obtain the close-packed atomic arrangements is examined as well. Finally, the influence of volume modification on phase transitions is investigated. The energies of various structural configurations are calculated using many-body potentials for the description of interatomic forces. Such atomic models are tested to check their suitability for investigation of the role of interfaces in the displacive structural transitions.
Pressure-Temperature Phase Relations in Complex Hydrides
Authors: Sundqvist Bertil
Published: March 2009

Interest in hydrogen as a future energy carrier in mobile applications has led to a strong increase in research on the structural properties of complex alkali metal and alkaline earth hydrides, with the aim to find structural phases with higher hydrogen densities. This contribution reviews recent work on the structural properties and phase diagrams of these complex hydrides under elevated pressures, an area where rapid progress has been made over the last few years. The materials discussed in greatest detail are LiAlH4, NaAlH4, Li3AlH6, Na3AlH6, LiBH4, NaBH4, and KBH4. All of these have been studied under high pressure by various methods such as X-ray or neutron scattering, Raman spectroscopy, differential thermal analysis or thermal conductivity measurements in order to find information on their structural phase diagrams. Based mainly on experimental studies, preliminary or partial phase diagrams are also given for six of these materials. In addition to this information, data are provided also on experimental results for a number of other complex hydrides, and theoretical predictions of new phases and structures under high pressures are reviewed for several materials not yet studied experimentally under high pressure.
Statistical Thermodynamics and Kinetics of Long-Range Order in Metal-Doped Graphene
Authors: Radchenko Taras M. , Tatarenko Valentin A.
Published: March 2009

The statistical-thermodynamics and kinetics models of atomic ordering in a metal-doped graphene (binary two-dimensional planar graphene-type crystal lattice) at 1/8, 1/4, and 1/2 stoichiometries are proposed. Impossibility of (completely) atomic-ordered distribution at 1/6 and 1/3 stoichiometries is ascertained in a graphene-type crystal lattice (in case of a short-range interatomic interactions at least). If a graphene is doped by the short-range interacting metal atoms, the superstructures described only by a one LRO parameter are possible; and if it is doped by the long-range interacting metal atoms, the new superstructures with the two or three LRO parameters may appear as well. If stoichiometry is 1/4, the structure has a one long-range order (LRO) parameter is more thermodynamically favorable than those have one or two LRO parameters. It is established that kinetics curves of LRO parameters can be non-monotonic for structures where there are two or three LRO parameters (because graphene-type lattice contains two sublattices, and mixing energy is different for each of them). It is shown that the most ordered is structure with equal atomic fractions of carbon and metal atoms, while the least one is structure with a maximal difference of carbon and metal atoms. Kinetics results confirm statistical-thermodynamic ones: firstly, equilibrium values of LRO parameter coincide within the framework of both models, secondly, equilibrium (and instantaneous) value of LRO parameter in a nonstoichiometric binary graphene-type structure (where atomic fraction of a doping component deviates from the stoichiometry to the side of the higher concentrations) may be higher than it is in a stoichiometric one. The dominance of the same physical mechanisms of atomic ordering in both mixed nanosystems and macrosystems is assumed.
Solar Power Devices for Providing Power to Handheld Devices: Field of the Invention
Authors: Elazari Ami
Published: March 2009

Battery powered mobile appliances have been booming for years. Examples include
power tools, laptop computers and mobile phones. A photovoltaic power supply makes batterypowered appliances more practical for users, since the batteries don't go flat. The idea of a solar bag for PDAs and mobile phones was born to satisfy energy needs while traveling, hiking, climbing, sailing, cruising especially for sales people and businesspersons when electricity is not available.
The success of the photovoltaic power supply is largely determined by lighting conditions: outdoors, a device is exposed to solar intensities of up to 1000w/m but indoors, under artificial desktop lighting or outdoors during overcast weather, the value decreases to 100w/m. The cells should provide close to maximum voltage already for very low illumination and for a very small area of cells for cellular phones, laptops and PDAs. These specifications are well met by highefficiency cells exceeding 14-15% efficiency in our devices.
We have developed a solar charging device for commercially available PDAs, mobile phones and laptops. The charging device consists of a 9-30 solar cell generator connected in string using black on black technology with an area of 5×12 cm and 1.5 watt related power with a low loss charge controller for the Li-Ion battery in the PDAs and mobile phones, and a 33×33 cm 10w power device for the laptops.
The present invention is related to solar power devices, which are capable of performing the conversion of solar energy to electrical energy (photovoltaic principle), and in particular which are useful for providing power to handheld devices, whether indoors (inside of a building or other enclosure) or outdoors (outside of a building or other enclosure).
Reaction Dynamics and Applications in Patterning of Bisthienylcyclopentene-Based Photochromic Switches
Authors: Hania P.R. , Pugžlys A. , Lucas L.N. , de Jong J.J.D. , van Esch J. , Feringa B. , Duppen K.
Published: March 2009

The structural and optical properties of the gel-forming photochromic switch 1,2-bis(2’-methyl-5’-{{((R) phenylethyl)amino}carbonyl}thienyl-3’-yl)cyclopentene are studied by means of the linear absorption and holographic grating techniques. The use of diffractive optics enables recording of holographic gratings with high long-term phase stability. The diffraction efficiency of the recorded holographic gratings approach values of 30% for low writing beam energies when diffusion is the rate determining factor. At higher writing pulse energies the competition between the diffusion and photodecomposition processes causes lower diffraction efficiencies. At irradiation doses above 10 mJ the spatial profile of the recorded gratings is strongly influenced by saturation effects. Because of the well-determined grating profile the holographic grating technique is potentially applicable for the quantitative characterisation of the diffusion process in photochromic gels.
Modelling Evolution of Nanostructures in Lateral Etching Processes
Authors: Navickas R. , Romanov M.
Published: March 2009

The model of the evolution of nano- and microstructures in the self-formation process of underetching (lateral etching) layers was created for analysis and design of new self-alignment and self-formation technologies semiconductor devices and integrated circuits. The program was realized on the basis of a personal computer with the processor INTEL PENTIUM 4 and MATLAB 5.3 software. The results of the simulation were given for the different initial configurations of nanostructures. The experimental investigations evolution of microstructures in lateral etching processes of amorphous and polycrystalline films were performed and the results presented.
Nondestructive Testing Method in Artificial Intelligence Real Time Systems
Authors: Kazanavicius Egidijus , Mikuckas Antanas , Mikuckiene Irena
Published: March 2009

Modern sonar and radar measurement systems are widely used in the field of nondestructive testing for a long time. Usually reference signal is emitted towards the object to be investigated and we get a signal, which is the sum of reference signal reflected from different plies. The task of signal processing is to determine time instances corresponding positions of certain ply, which allow analyzing structure of object. Usually the cross correlation function (CCF) of transmitted sequence and received sequence is calculated. If peaks were clearly identified in the
cross correlation function (CCF), it would be easy to determine time instances. Due to the noise some coherent peaks, additive to the expected peaks, appear on the CCF, which are confusing in regard to the clear distinction of target. In order to cancel effects of noise as much as possible some measures have to be taken for data manipulation noise cancellation, such as averaging, inverse filtering and so on. These signal-processing methods need a lot of floating point floating point operations and are time consuming. That is why the usage of such ultrasonic systems is limited in real time systems, which are the base for self-organizing systems. Amount of calculations depends on the length of reference signal, the length of reflected signal to be processed and the noise reduction method used in such system. A new system with reduced amount of calculations is considered in this article. In this system only parts of reflected signal corresponding peaks of CCF are processed. These parts are defined in acquisition mode and afterwards system enters measurement mode. New noise reduction method based on wavelet transforms coefficients thresholding is applied in this system. The length of reference signal impacts system noise immunity and amount of calculations. The main problem in ultrasonic non-destructive testing systems is to cancel out effects of the noise. The optimal length of reference signal for wavelet based signalprocessing method is defined. All these measures allowed significantly reduce amount of calculations in the self-organizing systems.
Semiconducting Nanowires: Properties and Architectures
Authors: Erts Donats , Polyakov B. , Saks E. , Olin H. , Ryen L. , Ziegler K. , Holmes J.D.
Published: March 2009

The paper describes the use of an in-situ microscopy technique, which combines
transmission electron microscopy (TEM) with scanning probe microscopy (SPM), to investigate the electrical and mechanical properties of individual silicon and germanium nanowires. Additionally, the formation of ordered arrays of size-monodisperse silicon and germanium nanowires within mesoporous silica powders and thin films using a supercritical fluid inclusion phase technique is described. In particular, we demonstrate ultra high-density arrays of germanium nanowires, up to 2
x 1012 wires per square centimetre. These matric embedded nano-composite materials display unique optical properties such as intense room temperature ultraviolet and visible photoluminescence.
Microstructure and Electrical Properties of Doped ZnO Varistor Nanomaterials
Authors: Kang Xueya , Minjing Tu , Zhang Ming , Tiandiao Wang
Published: March 2009

A sol-gel method of preparation doped ZnO varistor nanomaterials is described, The
influences of doped ZnO nanomaterials for varistor microstructure and electrical properties (nonlinear coefficient α, breakdown voltage V1mA , dielectric constant ε, and dielectric loss tan δ) are investigated. Compared with the conventional mixed oxide technique, varistor ceramic of prepared by nanometer materials showed a more homogeneous microstructure, smaller grain sizes, higher densities and excellent electrical properties.
Influence of Fine-Dispersed Dielectric Particles on Dye Luminescence in a Polymer Matrix
Authors: Tikhonov E. , Yashchuk Vasil P. , Prygodjuk O. , Bezrodny V. , Filatov Yu.
Published: March 2009

The behaviour of the luminescence spectra of the organic dye R6G in a multiple scattering polymer matrix was studied with reference to the parameters of the scattering media. It was found that some of the luminescent parameters depend on the concentration of scattering particles, the refractive index of the scattering particles and the sample thickness. As it was shown, that the reason for these dependences is the reabsorption of luminescence light enhanced by multiple light scattering. In addition, an increase in the absorption caused by multiple scattering was observed.
A Novel Thermosensitive Composite Fabricated with Au Nanoparticles, Poly(Lactide), and Poly(N-Isopropylacrylamide)
Authors: Jo Yun Suk , Kim Do-Kyung , Jeong Young Keun , Kim Kyung Ja , Muhammed Mamoun
Published: March 2009

A novel approach to load a hydrophilic bovine serum albumin (BSA) into the drug
carriers was proposed in terms of thermosensitive dual-shell structures which were fabricated with poly(N-isopropylacrylamide), poly(lactide) and Au nanoparticles. Spherically well-defined dualshell structures were constructed by a modified-double-emulsion method (MDEM). The lower critical solubility temperature of the structures was shifted to 36.4 °C which was confirmed by UVVis
spectroscopy.
Peculiarities of Formation and Growth of Thin Polymer Plasma-Deposited Films
Authors: Lyakhovitch A.M. , Dorfman A.M. , Shirobokov M.A.
Published: March 2009

Special features of the formation and growth of polymer films, formed on steel under the effect of glow discharge in heptane were studied by means of atomic force microscopy, X-ray photoelectron spectroscopy and contact wetting angle. At low film thickness a thin sticky layer is formed, from which macromolecular cone-shaped formations protrude. With an increase in film thickness the sticky layer disappears and the number of cone-shaped formations increase and they eventually coalesce. As the surface coverage with cones increases the films become thicker and stronger. The cones are assumed to be the film growth sites, which arise during the relaxation of the film’s internal stresses. In addition these growth sites can form under the effect of the stresses from extended defects in the substrate.
Structure of Alumina and Zirconia Nanoparticles Synthesized by the Karlsruhe Microwave Plasma Process
Authors: Schlabach S. , Szabó V. , Vollath D. , Braun A. , Clasen Rolf
Published: March 2009

Applying the Karlsruhe Microwave Plasma Process, alumina and zirconia particles with particle sizes in the range from 2 to 5 nm were synthesized. Additionally, the influence of small amounts of iron(III)-oxide, chromia, and magnesia on the crystallization and phase transitions in alumina powders was investigated. It is shown that these dopants may influence the crystallization behavior significantly. Especially, the addition of 1 mol% iron(III)-oxide reduced the temperature of the formation of a-alumina from 1200 °C to 300 °C.
Studies on the Preparation and Characterisation of Carbon Nanostructures
Authors: Kalenczuk R.J. , Borowiak-Palen E. , Pichler T. , Rümmeli M. , Fink J.
Published: March 2009

We present a study on the preparation of multiwalled carbon nanotubes (MWCNT) using chemical vapour deposition (CVD). The CVD produced MWCNT and single wall carbon nanotubes (SWCNT) produced with a laser ablation technique were then chemically modified by substituting carbon atoms with boron and nitrogen atoms. The morphology and the crystal structure of the new class of nanostructures were analyzed by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM).
Grains of Porous Silicon Embedded in SiO2:Studies of Optical Gain and Electroluminescence
Authors: Dohnalová K. , Luterová K. , Valenta J. , Buršík Jiří , Procházka M. , Křesálek V. , Hönerlage B. , Pelant I.
Published: March 2009

Recent reports on experimental observation of optical gain in silicon nanostructures in the visible region, performed at several laboratories all over the world, have triggered an extraordinary surge of interest in silicon lasing. However, attempts aimed at reproducing the red stimulated emission from „standard“silicon nanocrystals (sized 3-5 nm) at some other laboratories either failed, or. did not come to definite conclusions. Therefore, more detailed measurements of optical gain in a wider variety of samples containing Si nanocrystals are required in order to unravel whether or not the observation of optical gain is an intrinsic property of Si nanocrystals. We have performed a detailed study of optical gain in layers of densely packed Si nanocrystals in SiO2, prepared on the basis of porous Si, using the variable-stripe-length (VSL) method in combination with the shifted-excitation-spot (SES) method. In selected samples we have observed a distinct difference in behaviour between VSL and SES curves, indicating the occurrence of positive optical gain of ~ 24 cm-1. Preliminary reports on transport and electroluminescence measurements in thin films of SiO2 doped with porous silicon grains, prepared by spin-coating technique, are also discussed.
BAK
Authors: Moldoveanu Tudor , Liu Qian , Green Douglas R , Gehring Kalle
Published: March 2009

The effector BCL‐2 (B cell lymphoma‐2) protein BAK (B cell lymphoma‐2 homologous antagonist/killer) directly mediates mitochondrial outer membrane permeabilization to drive the mitochondrial pathway of apoptosis. The structures of BAK are presented to reveal two different modes of homodimerization. Noncovalent dimerization is mediated by one Zn2+atom to inhibit the release of cytochromecfrom mitochondrial intermembrane space. Covalent oxidative homodimerization occurs through disulfide bond formation at Cys166 and is thought to prevent the Zn2+‐mediated inhibition by abolishing the Zn2+‐dependent homodimerization interface. Neither mode of dimerization affects the putative B cell lymphoma‐2 homology 3 (BH3)‐binding pocket, which remains occluded in BAK to preclude high affinity BH3 peptide binding.
Germanimum: Organometallic Chemistry
Authors: Banaszak Holl Mark M. , Peck David R.
Published: March 2009

This article provides an overview of germanium organometallic chemistry from 1994 to 2007. Major advances in the formation and breaking of GeC bonds are discussed as are advances in the physical characterization of these compounds. Recent advances in the formation of organogermanium species containing multiple bonds to germanium and the formation of germanium‐centered radicals and cations are delineated. Applications to the synthesis of germanium‐containing polymers are overviewed.
Fullerenes: Metal Complexes
Authors: Balch Alan L. , Chancellor Christopher J.
Published: March 2009

This article reviews recent developments regarding the binding of metal centers to the outer surface of fullerenes and to the construction of nanoscale materials utilizing externally bound metal complexes. Developments in the coordination of single metal centers and metal clusters are discussed with particular emphasis placed on crystallographic characterization of the resulting assemblies. Electrochemical work on redox‐active films prepared by reduction of fullerenes and metal complexes is reviewed. The formation of metal containing heterofullerenes—cages of carbon atoms and metal atoms—is examined. Finally, the formation of new crystalline phases by cocrystallization of fullerenes and various metal complexes is examined.
Inorganic Nanotubes
Authors: Remškar Maja
Published: March 2009

The first synthetic inorganic nanotubes were reported in 1992, but owing to the simultaneous discovery of carbon nanotubes they attracted wide international attention only recently. They are distinguished by important peculiarities, from growth mechanisms to the various physical and chemical properties and possible applications. Further analogies to carbon nanotubes, fullerenes, nanobuds, and peapods are presented as the first hybrid inorganic nanotube structures, i.e., nanobuds and “mama” tubes. Their structural and morphological properties determining chemical stability and activity, transport properties, mechanics and interaction with other building blocks in composites are discussed in this article.
Nano/Microporous Materials: Hydrogen‐Storage Materials
Authors: Collins David J. , Zhou Hong‐Cai
Published: March 2009

Both traditional and newly synthesized microporous materials, including activated carbons, carbon nanotubes, zeolites, inorganic nanotubes, and hybrid organic–inorganic materials have been investigated for their ability to adsorb hydrogen. Uptake by these materials is physisorptive, with relatively weak interactions between the material and the hydrogen molecule. Many are able to uptake 1–3 wt% hydrogen at 77 K and 1 atm, and several can adsorb up to 6 wt% under high pressure, but none are currently able to meet hydrogen‐storage goals at near‐ambient temperatures. This review examines the accomplishments, challenges, and future directions in this nascent field.
Nano‐Microporous Materials: Hydrothermal Synthesis of Zeolites
Authors: Valtchev Valentin , Mintova Svetlana
Published: March 2009

This review focuses on the synthesis, crystallization mechanism, and crystal engineering of silica‐based zeolites. The introduction section provides a brief historical overview of zeolite synthesis and points out the main families of microporous solids. The main body of the article comprises two interrelated parts. The first presents basic information related to the zeolite crystallization, namely, (i) the key constituents of a zeolite‐yielding system; (ii) the reactions upon the action of mineralizing agent (OH−and F−); and (iii) the fundamentals of zeolite crystallogenesis. Emphasis is laid on the nucleation process, which is still not well understood. New insights into the zeolite nucleation gained by using colloidal and dense gel systems are discussed. The second part of the survey deals with in situ zeolite crystal engineering. Initially, the synthesis of nanosized particles is considered and then methods for the growth of large, at least 50 µm, zeolite crystals are presented. Further, the control of the crystal morphology via fine tuning of the synthesis variables is discussed. Hybrid zeolites obtained by grafting of organic functionalities during the crystallization reaction are also reviewed. Finally, methods for the synthesis of zeolites with hierarchical porosity are illustrated. This part is subdivided into two sections presenting polycrystalline hierarchical porous structures and single mesopore–containing zeolite crystals.