This PDF file contains the front matter associated with SPIE Proceedings Volume 8411, including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

It is known that internal energy flow in a light beam can be divided into the orbital flow, associated with the macroscopic energy redistribution within the beam, and the spin flow originating from instantaneous rotation of the field vectors inherent in circular or elliptic polarization. In contrast to the orbital one, experimental observation of the spin flow constituent seemed problematic because (i) it does not manifest itself in the visible transformation of the beam profile and (ii) it converts into the orbital flow upon tight focusing of the beam, usually employed for the energy flow detection by the mechanical action on probe particles. We propose a two-beam interference technique that permits to obtain appreciable level of the spin flow in moderately focused beams and to detect the orbital motion of probe particles within a field where the transverse energy circulation is associated exclusively with the spin flow. This result can be treated as the first demonstration of mechanical action of the spin flow of a light field.

Phase-change memory materials are promising for the next generation of non-volatile flash memory that will serve in new mobile computing entertainment and other handheld electronics. Among them are chalcogenide glasses Ge-Sb-Te (GST) which can exist in two separate structural states – amorphous and crystalline. Switching of the material from one to another state can be done by heating applying an electrical pulse or by exposure to intense laser beam. In the present work we report the changes of optical parameters of amorphous Ge₁Sb₂Te₄, Ge₁Sb₄Te₇, and Ge₂Sb₂Te⁵ thin films under heat treatment and light exposure. The illumination with white during 1 hour does not change the transmission spectra of the as-deposited amorphous film. The spot of phase change transformation of the amorphous material was observed when the film was illuminated with UV laser pulses. From the transmission spectra T=f(λ) the optical constants (Absorption coefficient α, optical band gap E_g, refractive index n, the average electronic energy gap E0 and the dielectric oscillator strength E_d were calculated. For Ge₁Sb₂Te₄ the value of E₀ is smaller than optical band gap E_g=1.08 eV obtained from the Tauc plot. Large values of the refractive index n are obtained for smaller E₀=0.931 eV and for large E_d=7.448 eV. The anealing of the amorphous Ge₂Sb₂Te₅ thin film at T=100 ^oC during t=4 min shifts the transmission spectra in the low frequency region. The anealing at higher temperatures makes the thin film non-transparent, e.g. take place the process of crystalization.

Metamaterials are artificially designed media that show averaged properties not yet encountered in nature. Among such properties, the possibility of obtaining optical magnetism and negative refraction are the ones mainly exploited but epsilon-near-zero and sub-unitary refraction index are also parameters that can be obtained. Such behaviour enables unprecedented applications. Within this work, we will present various aspects of metamaterials research field that we deal with at our department. From the modelling part, we will present tour approach for determining the field enhancement in slits that have dimensions in the 10⁴ times smaller than the incident wavelength. This huge difference makes it almost impossible for commercial software to handle thus analytical approached have to be employed. From the fabrication point of view, various 2D and 3D high resolution patterning techniques are used. The talk will describe the ones available within our group. We will present the electron-beam lithography approach for fabricating nano-antennae to be used in coupling of plasmonics waveguides to/from free space. Also, a 3D technique based on twophoton-polymerisation and isotropic metal deposition to fabricate metal-covered 3D photonic crystals will be discussed. From the measuring side we will present two THz based setups for obtaining material’s characteristics, both in the low as well as in the high THz range, thus having the possibility of describing a material from 0.1 to 10THz.

In this paper we report some experimental results concerning the absorption/transmission measurements in the canine oocytes. For this we used an argon ion laser radiation (having 514 nm, 502 nm, 496 nm, 488 nm, 477 nm, 472 nm, 465 nm, 457 nm wavelength). These absorption/transmission measurements have been performed using a UV/VIS high resolution spectrometer from Ocean Optics as detector. The objective of this paper is to evaluate some characteristics: refractive index, maturity and quality which characterize the canine oocytes. In our work, we have used a noninvasive optical method for evaluation quality of canine oocytes.

Radius, roundness and roughness, the three R are the necessary parameters to characterize ball bearings. Roundness is one of the most important geometric forms expected from circular features. Most traditional R³ measuring instruments are stylus type, including the coordinate measuring machines (CMMs). The accuracy requirements for roundness measurements range from a few 0.1 μm for work pieces down to below 10 nm for roundness standards such as precision spheres. White light interferometer is a suitable noncontact method for height profile measurement of objects able to furnish such values. White light interferometer (WLI) produced by Ambios Xi-100 was used to measure radius, roundness and roughness of steel ball bearings. Radius is calculated from the Newton rings easily observed in the interferometer, roundness is observed by limiting the height surface profile between two inner and exterior circles and roughness is RMS value for the best fit line to the ball profile. All the values can be easily obtained from the .txt files produced by the instrument software.

The resonances between the spontaneous and induced emissions by two- and single photon transitions of three inverted radiators from the ensemble proposed in paper⁴⁵ open the new possibilities in the manipulation of the decay rate of the entangled photon pairs generated by the system relative the dipole-forbidden transition. The influence of the bath temperature to such process is studied. One of them corresponds to the situation when the total energy of emitted photons by two dipole-active radiators enter the two-photon resonance with the dipoleforbidden transitions of third atom. Second effect corresponds to the scattering situation, when the difference of the excited energies of two dipole-active radiators are in the resonance with the dipole-forbidden transitions of third atom. These effects are accompanied with the interferences between single- and two-quantum collective transitions of three inverted radiators from the ensemble. The three particle collective decay rate is defined in the description of the atomic correlation functions.

The paper presents a new method for determining the degree of coherence of superposing plane linearly polarized waves converging at the angle of 90⁰. The spatial modulation of polarization, which causes the spatial modulation of the averaged values of the Poynting vector, presets the modulation of the volume energy density. Such an inhomogeneous optical field can affect nanosize particles, randomly caught in this field. It is shown that the maximum velocity of “trapping” the particles into the regions of maximum averaged values of the Poynting vector determines the degree of coherence of interacting waves.

The autocorrelation technique applied to diagnostics of phase singularities arising in diffraction patterns is presented for the first time. The proposed technique is based on the Young-Rubinowicz model of diffraction phenomena (model of the edge diffraction wave) and consists in analysis of bending or shift of interference fringes, which are produced by the waves from two edges of narrow opaque strip placed in the beam. This original approach has been applied previously for detection and diagnostics of optical vortices in Laguerre-Gaussian beams, in combined partially coherent/ partially polarized beams as well as in speckle fields. Here we show applicability of the same experimental approach for detecting another type of optical singularities, viz. edge (rather than screw) dislocations of optical wave fronts. Such technique is of especial importance when the use of separate reference wave (cross-correlation approach) is hampered due to incomplete spatial coherence of the analyzed beam or its complex polarization structure. We demonstrate practicability of the proposed technique with instructive examples of typical diffraction patters both in Fraunhofer and Fresnel zones. Besides, our experiments show structural stability of edge dislocations in diffraction patterns. Namely, if even amplitude zeroes are ‘hidden’, then autocorrelation technique provides detecting at least component singularity.

We present a novel application of the continuous wavelet transform (CWT) for quantitative analysis of electron diffraction fringe patterns for material science research. With this method unsupervised analysis of large data sets can be performed, to determine statistical distribution of fringe periods, corresponding to the spacing between the planes in the atomic lattice. It is more robust and less time consuming than typical manual approach. Obtained information can be further utilized for characterization and identification of the crystallographic structures present in the sample. The proposed method is applied to analysis of high resolution transmission electron microscope (HRTEM) images of Iridium-Zinc-Silicon-Oxide thin films, which reveal nanocrystallic structures dispersed in an amorphous matrix.

The optical model of polycrystalline networks of blood plasma proteins is suggested. The results of investigating the interrelation between the values of correlation (correlation area, asymmetry coefficient and autocorrelation function excess) and fractal (dispersion of logarithmic dependencies of power spectra) parameters are presented. They characterize the coordinate distributions of polarization azimuth of laser images of blood plasma smears and pathological state of the organism. The diagnostic criteria of breast cancer nascency are determined.

The possibilities of the local wavelet-analysis of polarization-inhomogeneous laser images of human blood plasma in order to discriminate between healthy and oncologically changed (cancer of cervix uteri) states were considered. The set of statistic, correlation and fractal parameters of the distributions of wavelet-coefficients that are characterize different scales of the polarization maps of polycrystalline networks of amino acids of blood plasma were defined. The criteria for the differentiation of the transformation of birefringence optical-anisotropic structures of blood plasma at different scales of their geometric dimensions were determined.

The article describes the principle and design of a standalone, mobile processing system which performs optical character recognition (OCR) in images acquired from a video camera. The system includes a powerful digital signal processor and implements image enhancements and pattern recognition algorithms. The device has IP Ethernet interface and is suited for remote applications, with low power requirements, high performance and low cost. Applications such as Automatic License Plate Number Recognition (ANPR), Automatic document electronic transcoding, and others can be accomplished using this system.

The sampling theorem can be described as a economic way of representing a limited bandwidth function. A sample of points is chosen and an interpolation function of these points is used to represent the function. The great importance of this fact is that paves the way to discrete computation. The sample points act as a sort of “highlight” points of the original function, and computation involving the entire function may be restricted to calculation using only the sample points. Moreover we were able to find some refining of the classical outline of the sampling theorem that improves its precision bringing also some physical insight into the core of the theorem. Of course also these consideration are not restricted to optics, they can be construed as general properties of the signal theory. But we were optically minded at all times and most of the applications are in optics.

We present a few experimental investigations of the passively mode-locked soliton fiber laser using two saturable absorbers to mode-lock the laser in order to underline the laser sensitivity at the change of sample propagation media. In this case the passively mode-locked fiber laser works like an opto-optic transducer, which has at the input optical parameters of the sample media and generates at the output different types of solitonic pulses which are related to the input parameters. In order to enhance the laser stability we try to compensate the errors by using a differential method.

This paper presents data on the method of determining the coordinate distributions of Stokes vector parameters laser images of biological tissue in the frequency Fourier plane. Presented by describing the experimental setup - Fourier stokespolyarymetr of biological tissues. The optical model of polycrystalline networks of histological sections of rectum wall is suggested. The results of investigating the interrelation between the values of statistical (statistical moments of the 1^st-4^th order) parameters are presented. They characterize the coordinate distributions of the fourth parameter of Stokes vector of Fourier transforms of laser images of rectum wall histological sections and oncological changes. The diagnostic criteria of rectum cancer are determined.

The modifications of optical parameters (optical band gap E_g, absorption coefficient α, refractive index n) under light irradiation by He-Ne laser of the amorphous thin films with different amount of Sn were measured and calculated. In the present work the transmission spectra of bulk and thin films of [(As₂S₃)_0.5:(As₂Se₃)_0.5]_1-x:Sn_x (x=0; 1; 2 at.%) in the visible and middle infrared (IR) regions were studied. The red shift of the fundamental absorption edge under light exposure was observed, and the values of the optical band gap E_g ^opt from the graphics in Tauc coordinates (α hν)^1/2=A(hν - Eg) were obtained. The dispersion of the refractive index was examined. The relaxation of the relative optical transmission T/T₀=f(t) under the light exposure (λ=633nm and λ=543nm) for amorphous [(As₂S₃)_0.5:(As₂Se₃)_0.5]_1-x:Sn_x thin films also was investigated. The relaxation curves of photodarkening under light irradiation were processing using the stretched exponential presentation of the data: T(t)/T(0) = A₀+Aexp[-(t-t₀)/τ] ^(1-β), where t is the exposure time, τ is the apparent time constant, A characterizes the exponent amplitude, t₀ and A₀ are the initial coordinates, and β is the dispersion parameter (0<β<1).

The transmission spectra of bulk and thin films of (As₂S_1.5Se_1.5)_1-x:Sn_x in the visible and near infrared (IR) regions were investigated. Doping of As₂S_1.5Se_1.5 chalcogenide glass with tin impurities essentially reduce the absorption bands of SH (Se-H) and H₂O located at ν = 5190 cm^-1 and ν = 3617 cm^-1, respectively. The amorphous As₂Se₃:Sn_x and (As₂S_1.5Se_1.5)_1-x:Sn_x thin films exhibit photoinduced effects under the light irradiation with photon energy above the optical band gap (hν≥E_g), that make its perspective materials for registration of optical and holographic information. The modification of optical parameters (optical band gap E_g, absorption coefficient α, refractive index n) under light irradiation and heat treatment of the amorphous thin films with different amount of Sn was studied. The shift of the absorption edge after light exposure to lower energy region was observed, i.e. the effect of photodarkening take place. The dispersions curves n=f(λ) show a modification of the refractive index n under light exposure. For the glass composition (As₂S_1.5Se_1.5)_0.96:Sn_0.04 the change of the optical band gap Eg^opt under light exposure was determined from 1.92±0.02 eV to 1.86±0.02 eV. The similar calculations of the optical constants were done for the amorphous films of glass compositions x=0.03 and x=0.05. The relaxation of photodarkening in amorphous As₂Se₃:Sn_x and (As₂S_1.5Se_1.5)_1-x:Sn_x thin films, which is described by the stretch exponential function T(t)/T(0) = A₀+Aexp[-(t-t₀)/τ]^(1-α) also wasinvestigated. The experimental results are interpreted in framework of the model of molecular structure of chalcogenide glasses doped with tin impurities.

Optoelectronic techniques can be applied for the study of transparent objects, followed by the processing of the recorded images on a video camera, after the laser beam passes through the investigated object. In this paper we present our study on a polycarbonate plate with optical polished surfaces, subjected on mechanical stresses perpendicular to the laser beam propagation axis. The results of this study include the values for material constants. Three experimental arrangements were employed: a plane polariscope, a circular polariscope and an interferometric setup. The recorded images in coherent light contain fringes variation with increased mechanical stress. They are processed using our MATLAB codes to determine the state of the stress at various points in the investigated sample. The measurements in a polariscopic assembly demonstrate the photoelastic properties of this composite material. In the plane polariscope arrangement, we can visualize the main stress directions and also the points with equal maximum shear stress magnitude; in circular polariscope we can visualize only the points with equal maximum shear stress magnitude; and in the interferometric setup are highlighted the refractive index variations which are linked with the phase changes and the applied stress. We apply the shift theorem from the Fourier theory, on the experimental images from the interferometric setup and on simulated ones.

Computer generation of holograms is a technique used to obtain a specific laser intensity distribution in far field starting from a desired image. In the process of hologram computing, the phase information must be considered. In this study we will present our code which ensures a fast link between the CCD camera (which records real macroscopic scenes), computer (where holograms are generated) and the spatial light modulator (where the holograms are displayed) to obtain on a screen a holographic displayed movie in real time. The aim of this work was to build interactive holographic systems. The challenge was not only to develop such a code, which can work for a suite of images taken by the CCD, but also to process them in a way that the delay of resulting reconstruction is unperceivable for human eye. For the veracity of the method we will present both simulation and experimental results.

The optical model of polycrystalline networks of the stomach wall histological sections is suggested. The results of investigating the interrelation between the values of statistical (statistical moments of the 1^st-4^th order) parameters are presented. They characterize the coordinate distributions of complex degree of mutual polarization in the points of laser images of the stomach histological sections. The diagnostic criteria of stomach cancer nascency and its severity degree differentiation are determined.

The complex technique of the concerted polarization-phase and spatial-frequency filtering of blood plasma laser images has been suggested. The possibility of obtaining separately the coordinate distributions of phases of linearly and circularly birefringent protein networks of blood plasma has been presented. The diagnostically sensitive parameters of a pathological change of the birefringence of blood plasma polycrystalline networks were determined. The effectiveness of the developed technique for detecting the change of birefringence of the blood plasma smears in diagnostics and differentiation of the acute and gangrenous appendicitis (exudate) is shown.

A novel device based on Silicon photonic crystal waveguides suitable for high density photonic integrated circuits was designed. This device is modeled starting from a previous developed device1, where the main part is consisted of a periodic dielectric multimode waveguide. The novelty of our work is that with our device any basic logic gate function can be achieved, and this is done by precisely calculating the phase differences needed between the input signals in order to obtain the 3-folded image wanted at the output of the multimode waveguide. Another important improvement is that the dimensions of the device are reduced by limiting to three the number of maximum allowed propagating modes in the multimode waveguide. Studying several symmetry lattices and dimensions and calculating the photonic band diagrams, the one which is most suitable for the device is kept.

A phase-shifting interferometry method to measure the wavefront reflected from a deformable mirror is described. Usually, an adaptive optics system encompasses a deformable mirror and a Shack-Hartmann wavefront sensor as the main components. However, an interferometric method is suited for calibration and traceability purposes of such measurements. In this regard, we developed a system able to characterize the wavefront in situ with both a Shack- Hartmann sensor and a phase-shifting interferometer. The method encompasses a reflective diffraction grating, where the plus-first diffraction order reflected off the grating was incident on a deformable mirror. This beam was then reflected back to the grating where it interfered with the incident beam and the interference pattern was collected on the minusfirst order. As with the four-step phase-shifting interferometry method, four interference patterns were recorded and processed to extract the wavefront information. The wavefront sensor recorded the wavefront directly reflected from the deformable mirror, via a beam splitter.

In this paper, the authors present, from theoretical point of view, some photonic logic gates based not only interference but also birefringence phenomena. An important advantage of these gates is the possibility of simultaneous processing of multiple light signals, with different light wavelengths, using a single logic gate. The presented photonic logic gates have many other advantages: they are fast, they are immune to electromagnetic fields, they can be use both in integrated photonics and in classical optics, the light signal remains all the time into optical domain etc.

This paper is a review of new possibilities offered by two photothermal (PT) methods, a contact (photopyroelectric (PPE) calorimetry) and a non-contact one (photothermal radiometry (PTR)) for accurate measurements of dynamic thermal parameters of condensed matter samples. Concerning the PPE method, the possibilities offered by the two main detection configurations, “back” and “front”, are analyzed and the information contained in the amplitude and phase of the PPE signal are compared. The applications of the technique refer both to liquid and solid samples. Concerning liquids, high-resolution measurements of thermal diffusivity and effusivity of some “special liquid samples” (volatile liquids, nanofluids,) are described. Several particular PPE detection cases, used for thermal inspection (measurement of thermal parameters, detection of phase transitions, etc) of solids were also presented. The PTR technique was used in the back configuration, together with the thermal-wave-resonator cavity (TWRC) method. This configuration allows for coupled PPE-PTR experiments. A comparison of the two techniques is presented and future developments are analyzed.

The rapidly developing field of data mining and knowledge discovery in data is a blending of artificial intelligence, statistics, and human–computer interaction. The task of data mining is to determine the data pattern from a given set of data. This paper shows the usage of an algorithm of data mining based on clustering, in order to find different data categories in a wind farm data. Once these data categories have been identified, the most suitable prediction technique can be determined. The authors study several Artificial Neural Networks (ANN) topologies in order to establish the most accurate one for every found data category. The experiments were done using real data acquired from a monitoring sensor system.

This paper describes a real case of methodologies and hardware and software systems used to build the road from electrical signal to information. The information in this paper is organized and presented with respect to ISA-95 standard [1], which is the international standard for the integration of enterprise and control systems. The road consists of data acquisition from sensors, software processing, data interpretation, data transmission and historization. The paper handles data acquisition circuits, transforming data into information using original algorithms developed under LabVIEW environment, sending the information to a remote database by using different kind of transmission mediums (ex. fiber optics, copper) and communication protocols (ex. Modbus, TCP/IP, OPC). The novelty consists of the LabVIEW algorithms and methods of using graphical elements on the user interface, which are actually the instruments that transforms data into information. This kind of systems is commonly used in industrial automation applications and laboratories with contribution in increasing efficiency, quality and safety of production processes. The main achievement is a powerful and robust solution that suits for different kind of industries. My personal contribution is the software application and achieving an original synthesis, study and approach of data acquisition and transmission systems.

The following essay has the purpose to realize and design an optical machine for the study of dental occlusology in order to improve it by establishing the force distribution diagram of the patient’s chewing profile, diagrams of great importance for obtaining a great dental work result.

In this work, a digital illumination system that serves to illuminate the reticles of a zoom riflescope with a special construction, is presented. Usually a zoom riflescope is equipped with a reticle located at the front or at the rear focal plane. Recently a new design with two reticles, in the first focal plane (FFP) and in the second focal plane (SFP), was developed for riflescopes with dual use: precision aiming and close quarters battle (CQB). It was first realized a riflescope with the two reticles illuminated in different colors trough a digital system providing multiple levels of control and setting.

The paper aims to address the issues of circuit integration of organic thin film transistors (OTFT) into a ring oscillator module. The stress falls on the optimization of the connections of the inverters in each of the stages of the presented three-stage ring oscillators. The organic transistors, with Bottom Contact Top Gate architecture, are fabricated using commercially available materials and accessible deposition techniques, such as spin-coating and metal evaporation. Two ring oscillators are fabricated with manual and patterned interconnections. The first circuit has a widthlength ratio of 1:10 between the load and drive transistors, while the second structure has a 1:30 ratio. The current-voltage measurements on the individual transistors, as well as the electrical measurements onto inverters and onto the whole circuit, are performed with a Keithley 4200 Semiconductor Analyzer. All measurements are done in accordance with the 1620.1 standard, in air and under normal ceiling fluorescent light illumination. The stability of the individual devices and the overall circuit is proved to remain constant under normal working conditions.

The paper aims to describe the fabrication of organic transistors and their integration into hybrid circuits on flexible substrates. Organic thin film transistors (OTFT) are fabricated using commercially available materials. The Au S-D electrodes are realized by photolithography, while the organic semiconductor and organic dielectric layers are spincoated. Finally, the Au gate electrode is evaporated in order to obtain a Bottom Contact Top Gate OTFT architecture. The paper presents a prototype realized in classic technology on rigid substrate, which is used to perform a PSpice simulation of the circuit. After the PSpice simulation, a module on PET substrate is made with organic transistors. Two transistors are employed to build the inverter used to switch the LED, while a third transistor is diode connected and acts as a 10MOhms resistor. The electrical characterization of the transistors and measurements onto the module are performed with a 4200 Keithley Semiconductor Analyzer. An SMD LED, in 0402 package, is used and all interconnections are done manually using Silver conductive paste, which dries at room temperature. The paper describes the circuit simulation and layout realization.

The results of research into Surface Acoustic Wave – SAW – filters have been recognized for their efficiency and versatility in the electrical signals processing ^1,3. Gallium Orthophosphate (GaPO₄) is a relative new material, which has a long term high stability and, moreover, has an excellent behavior with temperature variation ^2,3. The characterization of SAW filters based on GaPO₄ is uses the comparative analysis of simulated results of parameters, with different software programs, which were developed for designing of these filters. Simulation covers the determination and analysis of the characteristics of this filter, namely, mechanical parameters (constructive) and operational parameters in comparison with the design data. In order to obtain the parameters of SAW filters we have used the algorithms and software for modelling, simulation. The paper presents several versions of software programs, in Matlab and Microsoft Visual C#, for the design of GaPO₄ SAW filters and their interpretation. These modeling, simulations were performed successively by each program, until we set the parameters of SAW filter. By the comparison of the data obtained with each program, we have improved the constructive dimensions of fingers, we obtained the desired parameters. With this data, we realised SAW filters based on GaPO₄, and with the help of the Network Analyzer we measured parameters of the filter, which are presented in the paper^2,10.

Optoelectronics is facing with an ever dynamic increasing in our lives. We feel a growing demand for specialists in design and operation of optoelectronic systems. In accord with this demand Politehnica University of Bucharest (PUB) has introduced optoelectronics curricula since 1992 year. The theoretical courses are covered by laboratory activities, to provide the students with actual experience of optoelectronic systems. Some experiments are presented in this paper. To get a good efficiency of experiments, the student should study Laboratory guide manual, before entering the laboratory. PUB in collaboration with SPIE organization is intending to develop an integrated optoelectronics laboratory for education ofoptoelectronics specialization students with the following principles: define the educational goals and experimental laboratory courses to fulfill the objectives, design the instrumentation and systems to enable practical, experimental investigation and measurements; elaboration of experimental algorithms and laboratory guide for students, which include exercises and problems with responses connected with real world of optoelectronics specialists demand. This paper focuses on the presentation of laboratory courses that would be developed a meaningful understanding of optoelectronic devices, and systems.

Nowadays the battery of choice for an electric vehicle (EV) is the Li-Ion. To match the range of an internal combustion powered vehicle, the EV needs a battery capable of delivering 30–50kWh (commonly the standard capacity is 15 to 20 kWh). The present paper represents a study on a proposed hybrid supercapacitor-battery electric system to control a reversible electric motor used in demanding application or in automotive applications. When an AC electric motor is used the deceleration energy (power generation control) is recovered and stored in a battery of supercapacitors. The designed method uses an electronic control module that has minimal electromagnetic interference due to switching of the power semiconductor device as it passes through zero voltage and filtering of conducted emissions. The supercapacitor battery allows rapid storage and release of energy of 300 - 400A if needed without using the energy stored in the battery system increasing its life cycle.

Differential inductive displacement sensors are widely used in hydraulic applications because they offer good accuracy, large displacement range (up to 200mm) and have a rugged construction. Displacement information is usually extracted with analog electronics techniques - sinusoidal excitation of coils, quadrate modulation and synchronous demodulation – but this method is not well suited for implementation in digital embedded systems. Using a novel method for displacement measurement, based on switching voltages applied to the coils of the inductive device, the displacement sensor can be implemented with a standard microcontroller with integrated analog to digital converter and timer. Commissioning, configuring and data communication can be performed using standard serial interface. To avoid wires and cables, an infrared communication based on a standard IrDA transceiver module can be implemented. Presented paper focuses on measurement and construction aspects of an inductive displacement sensor with infrared communication interface option implemented and tested by authors.

Considering ecotoxicological effects on environmental and biota of a wide range of organic pollutants a stricter and combative campaign emerged at worldwide level in terms of their use and discharge into the environment. In the last decades, only in the European Union were created a large number of restrictive regulations of such organic chemicals, regulations that extend to all environmental matrices as water – European Water Framework Directive (WFD- 2000/60/EC), marine environment – European Marine Strategy Directive (MSD-2008/56/EC), soil – European Soil Framework Directive (SFD-2004/35/EC) and for different departments as chemical safety and use or biocides use, European Regulation for Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) and Biocides Directive (Council Directive 98/8/EC), respectively. Today mutagenic pollutants as polycyclic aromatic hydrocarbons (PAHs) are widely present at global scale, acting continuously on “biota’s health”. Therefore improvement of mass spectrometric detection of PAHs and their possible metabolites become an important issue in eco-toxicological fields. Once to could perform their mass spectrometric analysis optimization of PAH compounds isolation from complex biological matrixes (as vegetal, animals and human biological samples) had to be made. As isolation technique solid phase microextraction (SPME), liquid-liquid extraction (LLE) and headspace extraction- solid phase microextraction (HS-SPME) were improved obtaining the recovery factors between 72 – 118 %. Optimization of chromatographic-mass spectrometric (GC-MS) analysis procedures of these mutagenic species permitted their detection from such complex biological matrixes at very trace levels, namely between 0.06 – 0.47 ng⋅kg^-1 dry weight.

he antennas presented in this paper are designed to work with the RFID reader designed in-house by our company, but also with the new transponder that will be produced. The reader and transponder are compatible with all 13.56 MHz RFID know standards: ISO10536 (close coupling, 0…1 cm), ISO14443 (proximity coupling, 0…10 cm), ISO15693 (vicinity coupling, 0…1 m) and the other standards patented by the companies that developed them (e.g. FeliCa^TM by Sony) [1]. Similar methodology, as the one described in the presented paper, can be used for design/ development of wireless chargers antennas and their frontends [6].

In the case of construction works, nondestructive determination of some key parameters is required, parameters that ensure safety and quality of constructions. Among these parameters one can mention: the thickness of the layers of which a road or highway is made; the degree of compaction (especially for the wear layer of a road or highway); the thickness of the bearing elements for a civil or industrial construction; the material type of which the construction is made; the existence of cracks in the case of the bearing elements. From this enumeration of parameters are found to be necessary determinations with ultrasonic waves that can be broadcast (in case both sides of the layer are accessible) or by reflection (in case only one side of the layer is accessible) and there are a large variety of material types that are used, materials having different homogeneity. In the following, the measurement types and methods along with their advantages and disadvantages, as well as some measuring devices will be described.

Thin films (1-10 μm thickness) of nanocomposites (NCs) based on coordinated compounds (CC) Tb(TTA)₂(Ph₃PO)₂NO₃ (where TTA is thenoyltrifluoroacetonate (C₈H₅F₃O₂S), Ph₃PO - triphenylphosphine oxide) and polymer – polyvinylpyrrolidone (PVP) ((C₆H₉NO)n)) were obtained by chemical methods. NCs were characterized by measurements of optical transmission (T(λ)), and photoluminescence (PL) at different concentrations of CC in NCs. Using the optical transmission spectra, the characteristic parameters of NCs such as threshold of absorbance and the position of the absorption edge versus the concentration of the CC in NCs, etc., were determined. A slight displacement of absorption threshold to infrared region was observed with increasing of concentration of coordinated material in NCs. It was established that the excitation spectrum at which the photoluminescence (PL) in NCs take place covers the range of wavelengths from 200 to 410 nm. The PL of nanocomposites was detected as specific for internal transitions 4f → 4f of the Tb³+ ion ⁵D₄ →7Fi (i = 6, 5, 4 and 3) centered at 488, 543, 589 and 614 nm, respectively at T=300 K. The dominant PL was observed at 543 nm and its halfwidth is less than 10 nm. The intensity of photoluminescence signal at 543 nm in the case of NCs films is 2 times higher than the intensity of PL of Tb(TTA)₂(Ph₃PO)₂NO₃powders at equal conditions of excitation. PL intensity of the NCs to 77 K is growing more than 20 times compared with that at 300 K.

The present paper describes the fabrication and electrical characterization of printed capacitors using polyvinylphenol (PVP) as dielectric. The recently developed drop-on-demand inkjet printing technology was used to fabricate the components. The printing ink SunTronic EMD 5603 with silver nanoparticles was used to deposit the capacitors’ plates. Two different types of structures have been produced. One structure has a single layer of PVP dielectric material, while the second capacitor has two layers of insulating material. The aim of the work was to determine the influence of the dielectric thickness on the overall capacity of the device. The structures were submitted to thermal curing treatment prior to measurements. The measured capacity of the devices ranges from 40pF to 400pF depending on the thickness of the dielectric layer.

Until now, very few systematic studies have been made for comparing various photodiode structures in terms of their performance characteristics. Most of the studies included only few structures, some of them only simulated, without experimental measurements. Unfortunately, all these studies comprised only a few photodiodes, and in our knowledge there is no extended study to compare all types of CMOS photodiodes, fabricated using various CMOS processes. In this paper we will try to fill in this empty space in this area, in order to provide an easier choice of the most appropriate CMOS photodiode (and thus of the CMOS image sensor) to be used in a certain application, according to the desired characteristics for each situation. We will review some important studies in which essential parameters for the characterization of the CMOS photodiode were evaluated: quantum efficiency, photocurrent and dark current. We consider that this paper will provide a useful reference for choosing the most suitable photodiode and CMOS image sensor for a very large area of applications.

Applications of CMOS image sensors can be found nowadays in an incredibly large range of domains. In this paper we present a review of the main applications of these devices in the latest years, in domains like medicine, astronomy, automotive field, digital photography etc. We also highlight the capabilities of these CMOS sensors that constitute advantages over their competitors, the CCD sensors, and which imposed them for specific applications. Since the late 1960s when they appeared, CMOS image sensors have evolved a lot. Whereas in the beginning their performances could not be compared with those of the CCD image sensors, since the late 1990s CMOS sensors became real competitors of CCDs, both in industrial and scientific fields, due mainly to several important advantages, such as low power consumption, low voltage operation, high-speed imaging, low cost, integration capability etc. Prior work on CMOS image sensors reviewed mainly new types and structures, touching only tangentially the range of applications. Our paper proposes to partially fill this gap, presenting the most recent developments in a large area of domains of applications, providing the researcher with a quick reference for the state-of-art applications of CMOS image sensors.

The extensive use of pharmaceuticals became a worldwide environmental issue. Most of these compounds are not completely removed in wastewater treatment plants and, as a result, they are found in surface and ground water. In this report the behavior of two drugs, Thioridazine and BG1188 were investigated after their exposure in aqueous solutions to laser radiation. The degradation processes were monitored using spectroscopic techniques (Absorption Spectroscopy, Laser Induced Fluorescence, NMR Spectroscopy) and chromatographic methods (HPLC-MS). The Thioridazine 5x10^-2 M solution was irradiated up to 11 min and, respectively, BG1188 10^-3 M solution was irradiated up to 30 min, both with 355 nm Nd:YAG pulsed laser beam, with 30 mJ average pulse energy on the sample. The exposure of Thioridazine solution to laser radiation leads to the appearance of new VIS/NIR absorption peaks, while the ¹H NMR spectrum of 11 min irradiated Thioridazine 5x10^-2 M solution indicates modifications both in aliphatic and in aromatic protons regions. The HPLC-MS measurements highlight a change of Thioridazine in two metabolites: Mesoridazine in the first instance and Sulphoridazine finally. The behavior of the irradiated BG1188 10^-3 M solution according to the evolution of the absorption and laser inducedfluorescence spectra highlights a photodecomposition of the initial solution and the appearance of new photoproducts. All the investigated solutions exhibit the photodegradation of the initial compounds, which allows us to consider that the exposure of solutions containing pharmaceutical products to laser beams may constitute a possible mean to remove these kinds of pollutants from different wastewater sources.

Possibility to machine the metallic materials by means of a laser beam depends on the capacity of these materials to absorb the respective laser radiation. In the case of a laser beam heaving a wave length λ=1070 nm, the experimental researches showed that among the common metallic materials, the steel absorbs the laser radiation, allowing the applying of some laser beam machining processes, while the copper, the aluminum and the bronze cannot be machined by means of the laser, for an output power of the laser equipment up to 300 W. Due to their high capacity to reflect the above mentioned laser radiation, such metallic materials (aluminum, copper, brass) cannot be significantly affected by the laser beam action and, therefore, they could not be machined by means of the laser radiation having a wave length of 1070 nm. Some considerations were elaborated by taking into account the phenomena developed at the contact zone between the laser beam and the surface layer of the workpiece. A part of the laser beam energy is absorbed, determining the material melting and vaporizing; another part of the laser beam is reflected by the workpiece surface in the case of copper, aluminum and brass. Some explanations concerning the effect of the laser beam exploited during the laser beam machining were developed, inclusively by means of the thermal properties of the workpiece materials.

Polyaniline/poly(aniline-N-propanesulfonic acid) (PAnPS) composites with different polyaniline content were obtained by chemical oxidative polymerization of aniline in presence of PAnPS which was used both as template and water soluble dopant. The influence of PAnPS in composites structure was also investigated. The composites were soluble in water until 0.3:1 molar ratio while they were soluble in polar solvents for all molar ratios. Characterization of the composites was performed by FT-IR, UV-Vis, XRD and TGA studies and the morphological studies were carried out by scanning electronic microscopy (SEM). Cyclic voltammetry studies showed only on set of redox peaks over the potential range of 0.0 to 1.5 V that suggests the PANi/PAnPS are true molecular composites.

Organic Electronics (OE), named also FOLAE (Flexible, Organic, (Printed) and Large Area Electronics), is a new branch of electronics, dealing with polymers and plastics, in contrast with traditional electronics, which is based on silicon, copper, oxides, etc. OE acts as a catalyst for the cost effectiveness on the market, being an emerging and fast growing field with high potential in industry. Some OE products (as OLED displays) are already on the market and others (as solar cells, lighting, transistors, etc.) are ready for it, being in the small volume manufacturing stage. Europe has a leading position in OE, mainly due to R and D collaboration, and various European projects try to strengthen this position. On these terms, the paper wants to offer an overview in teaching OE for development of future electronic systems, being destined not only to academia, but also to SMEs, professional associations, and research institutes for exploiting the synergies and complementarities of traditional electronics and OE [6].].

The solar panels (SP) are the main energy source especially for the new generation of nanosatelit. Having an area of around 100mm², SP are obtained by soldering photovoltaic (PV) cells on the surface of a dedicated printed circuit board (PCB). The power and voltage values generated have been obtained by the interconnection structures of PV cells used to realize SP. The soldering process could be manually or reflow type, when are used surface mounted technologies (SMT). The process constrains are generated by the PV cells’ structure and materials. In this paper the authors proposed vapor phase soldering (VPS) technology for assembling PV cells based on germanium, having maximum 0.5mm thickness, in order to avoid the mechanical damages which appear in the manual soldering process and to provide uniform heating with the peak temperature less than 150ºC. The novelty of the proposal consists in realizing the control of VPS process in order to obtain a precise and repeatable thermal profile (TP) below VPS liquid boiling point. Based on the experiments already done, theoretical studies and experiments regarding the heat transfer in VPS process there will be developed, in order to define a technology for assembling SP module with PV cells soldered into one step.

From all type of external stimuli the light rays are most commonly used because it involves only photochemical processes easily to control. One of the most studied of photochemical processes is photoisomerization groups, in particular the azobenzene groups. The azobenzene and his derivatives, known for Z(sin)-E(anti) reversible photoisomerization properties, have been extensively used as functional groups to synthesize various photosensitive compounds. The UV irradiation at different time of modified maleic anhydride - styrene copolymers with azo dye solutions were with UV light to increase the rate of Z(sin)-E(anti) isomerisation. The changes in the spectral absorption domain for azo compounds, a decrease in optic absorbance after irradiation, with a predisposition to come back at primary value was made with SECOMAMS750 UV–Vis spectrophotometer.

Metalloporphyrins have relatively high thermal stability, which makes them attractive candidates for high temperature catalytic process [1]. Thermogravimetry (TGA) have been used to examin the thermochemistry, to study the thermal stability and thermal decomposition of the new complexes of porphyrins. The composition of these compounds were determined from the TGA curves. A systematic study of the stability of tetra-p-phenyl-porphyrin (TPP) and its metallic complexes with [Ni(II), Co(II), Mg(II), Ti(IV), W(VI) and VO(IV)] through thermogravimetry (TGA/DTG) has been carried out. Metal complexes derived from porphyrins are fairly stable to thermal and oxidative decomposition, and parameters of that process depend on the number of axial ligands. The central metal ions have some marked influence on the thermal stability of the compounds [2]. All these compounds are stable up to the temperature range 400-600 ⁰C and decompose in an almost single major stage, which is used for kinetic parameters evaluation. In certain cases, a second minor decomposition stage is obtained.

Transparent thin films of polyepoxypropylcarbazole polymer were produced using spin-coating technique. Optical materials constants such as refractive index of thin films and thickness were determined by optical spectroscopy. It was shown the possibility of variation of film thickness by polymer concentration in solution. It was shown that film thickness dependence on the concentration of solution is linear. Therefore this linear dependence can be used to predict the film thickness of spin-coated polymers if the solvent is known. The thickness can be varied from 170 nm up to 940 nm for the solution with concentration from 2.5% up to 12.5%. To confirm the validity of our method, we also carried out the interferometric thickness measurements and analysis with a thin film of polyepoxypropylcarbazole. The difference of obtained results of two methods averaged not more than 5%. The measured film thickness by transmission spectra of the polymer film was found to be well correlated to the results of interferometric thickness measurement. The refractive index of the polyepoxypropylcarbazole was 1.62, which was well above the refractive index of 1.49 for polymethylmethacrylate. It was found that the inclusion of even a small amount of a photosensitizer, such as CHI3, was effective in producing of high refractive index material with refractive index 1.64.

In this paper, tin 5,10,15,20-tetra-p-phenyl porphyrin (Cl₂Sn-TPP) encapsulated in a natural zeolite (clinoptilolite) and in synthetic zeolites (X-71, HZSM-5) were synthesized (by direct adsorption into the matrix cavities) and characterized by TGA/DSC, UV-Vis and FTIR techniques; subsequently, they have been tested as catalysts in the hydrogen peroxide decomposition reaction. UV-Vis and FTIR techniques put into evidence the highest adsorbtion rate of the metalloporphyrin on clinoptilolite. The thermal analysis of these materials explained their thermal behaviour, as a useful criterion for their application as catalysts in reactions that involve high temperatures, showing that the porphyrin – zeolite materials are resistant to high temperatures. Regarding the use of these materials in the decomposition of hydrogen peroxide, the best activity was encountered in the case of SnCl₂ – TPP/clinoptilolite when compared with the free zeolites.

The paper presents a new project about Polymeric Wikia software evolution, which offers a generic platform for developing collaborative applications, in the field of “Advanced Polymeric Materials” using wiki paradigm and products. This application is a sharing knowledge space and storage resources in educational web environment. The Polymeric Wikia community is an important center to exchange information, knowledge, experiences and ideas about advanced polymeric materials. Interaction of members of this community will surely lead to new development and researches opportunities in the context of the global knowledge achievements. There is a need to develop a virtual community dedicated specialists in the field of advanced polymeric materials. This project is developed under the GPL open source license. The application includes information about design, production, processing techniques, main manufacturing process and important recovery and recycling methods of polymeric materials. PWikia (Polymeric Wikia) shares knowledge and expertise beyond the boundaries of traditional applications and websites. PWikia, as a repository of knowledge, offers a collaborative environment for further developments leading technology in advanced polymer materials.

Nickel doped SnO₂ films with special optical, electrical and magnetic properties have attracted more attention for practical spintronic applications. The present work aims to obtain Ni doped SnO₂ films deposited on the glass and silicon substrates by sol-gel method. The as-prepared films and thermally treated ones (at 500°C for 1h) were characterized by Scanning Electron Microscopy (SEM), Spectroscopic Ellipsometry (SE) and UV-VIS transmittance measurements. The obtained films are amorphous according to X-ray diffraction patterns. After three layer depositions, similar film thickness were obtained (around 200 nm), on both type of substrate used. The influence of the substrates and number of depositions on the structural and optical properties of the Ni doped SnO₂ films was established.

Transparent conducting oxides (TCOs) are an integral part of modern optoelectronics such as flat panel displays, solar cells and infrared reflection glasses. Tin-zinc oxides (ZTO) films show n-type electrical conductivity and high visible transmittance. In recent years Zn-Sn-O films have attracted much attention as new materials for transparent conducting oxides (TCOs) and amorphous oxide semiconductor films (AOSs). In the present work Zn_1-x Sn_xO_2-x (where x=0; 0.025; 0.975; 1) films have been obtained by dip coating sol-gel route on silicon and glass substrates. The as-prepared and thermally treated films for one hour at 500ºC were characterized by appropriate methods. X-ray diffraction was used for structure analysis of the films. The surface topography of the films was investigated by atomic force microscopy (AFM). The optical constants (refractive index and extinction coefficient were calculated from Spectroscopic Ellipsometry (SE) data using Cauchy Model. Fluorescence emission was observed in the case of studied films excepting tin dioxide. The structure, morphology and optical properties of the obtained films depend on the composition, number of deposition and thermal treatment temperature.

In this communication, we present results of investigations of the influence of technological conditions upon the properties of GaP nanoparticles produced by using a new precursor as a source of Ga atoms. The obtained nanoparticles were investigated by means of XRD, EDAX, and ТЕМ as well as by means of Raman light scattering and photoluminescence spectroscopy. The sizes of nanoparticles obtained with gallium acetylacetonate as a source of gallium are in the range of 10-40 nm according to estimations from TEM analysis. These values correlate with the position of the short-wavelength emission maximum in the photoluminescence spectra. A method of electrophoretic deposition of GaP nanoparticles from colloidal organosol solutions was elaborated. Raman spectra and XRD patterns, as well as optical transmission spectra have been measured for layers of GaP nanoparticles produced by this method.

When speaking of sensitive artifacts, control of the environmental conditions seems to be the best means of protecting theme. In theory, for a well preserved and uninfected artifact the best way to prevent fungal growth is to protect surfaces from contamination, control moisture and relative humidity (RH). For already biodeteriorated or fungus-infected artifacts, several methods, such as vacuum cleaning, freezing, heat treatment, chemicals, altered atmospheric gases or radiation, could be used. Realistically speaking, these methods often cannot be applied for some disadvantage of their use or because their high cost. This is why the aim of our research is to propose alternative chemical methods, based on natural extracts and/or synthetic chemical compounds for the removal of fungus from affected artifacts. To obtain remediation of the biodeterioration of the artifacts, we used mixtures of hydroxyapatite and alkali-metals hydroxides dispersed in isopropyl alcohol. An example of the treatment effectiveness is presented, using a selected recipe. Also, natural extracts were evaluated for their use in the bioremediation of the artifacts.

Our target was to implement a multiple biometric identification solution that integrates face recognition, fingerprints recognition and iris recognition technologies into one system¹. Both hardware and software for the biometric identification have been developed in order to achieve our goal. The system is controlled by embedded software that enrols, manages and identifies the users in one centralized database, which can be remotely accessed by the identification units through a VPN connection.

The omnidirectional vision can be achieved by using a convex mirror placed in front of a camera. In this way, the camera acquires a panoramic image that covers 360^o of the surrounding environment. This concept has been the aim of many researchers and has had various setups so far, using different mirror profiles, camera models and type of lens. Our target was to implement a robust surveillance system, for indoor and outdoor use, day and night vision capable, which could be easily integrated in the IP environment. Both hardware and software for the image processing have been developed in order to achieve our goal.

Early detection of malignant transformation is a goal of modern medicine and to this end there is an impressive number of approaches from the scientific field that tries to identify early changes preceding malignant transformation in order to establish a correct diagnosis. This paper aims to combination of polarization and fluorescence techniques for identifying the changes in biotissues of growth and development of experimental solid tumors.

The present paper focuses on cooling systems, based on Joule-Thomson effect, that include condensers and vaporizers, having the role of eliminating the heat flux generated by electronic components. Temperature reduction is ensured by an isenthalpic expansion of refrigerating agent in the laminating element. As technology evolved, mini heat exchangers developed today use micro and nano-channels. Better understanding of phenomena occurring within these devices is therefore required. The present paper illustrates results obtained for a mini heat exchanger having rectangular microchannels with a transversal section of 40 μm by 0,35 mm. Mini heat exchanger plates illustrated in this paper were built using a method developed in the Heat Transfer Laboratory from the Suceava University. The refrigerating agent employed was R12 Freon.

A photonic crystal with two-dimensional (2D) periodicity integrated narrow band filter is presented in this paper. A combination of waveguide – cavity – waveguide based on photonic crystal with 2D periodicity is used in order to obtain an integrated, high performance narrow band filter. Through the Finite-Difference Time Domain simulation of light propagation, we demonstrate a good performance regarding the band and area of the filter that can be used in photonic integrated circuits.

II-VI semiconductor nanostructures are particularly interesting due to their potential applications in novel optoelectronic devices. There have been many advances in the field, but relatively little work has been done on II-VI semiconductor low-dimensional systems under non-resonant laser radiation. Although the potential outcomes may be important for designing tunable optical devices, they involve complicated numerical techniques. Dealing with nano-scale problems frequently implies tricky mathematical issues as the non-analytical solutions. In this paper we investigate the effects of the laser field radiation on the electronic subband levels in cylindrical CdS/SiO₂ quantum dots. Understanding the laser effects on the oscillator strength for the intraband transitions in CdS/SiO₂ quantum dots may be relevant in the quantitative interpretation of the future experimental data related to this kind of structures. Our results prove that laser radiation could be used for tuning the quantum dots optical absorption/emission.

In this paper we are analyzing the coupling between laser radiation and surface in order to set the optimum work conditions to obtain nanoparticles by laser ablation in liquids (LAL). In this idea we have studied the effects induced with a 355 nm wavelength Nd:YAG pulsed laser on an aluminum target situated in distilled water with non contact profilometry (WLI Xi-100) and by optical microscopy (Carl Zeiss microscope). We have measured, analyzed and intercompared the characteristics of the formed craters (diameter, depth and shape) on the aluminum target as a function of the laser radiation parameters (incident fluence, number of pulses).

Azo-polymeric materials present in the last decade a great interest due to their applications. Our materials are based on polysiloxanic chains, modified with different azo-benzenic groups. This new class of hybrid polymer (organic/inorganic) gives a large potential of applications in biology, chemistry, sensors, microelectronics etc. Due to photo-chromic properties of the azo-polymers it is possible to apply two kinds of techniques for surface relief gratings (SRG) generation, necessary for using the polymers in enumerated applications: continuous or pulsed light irradiation. Our work was focused on SRG generation on azo-polymers by pulsed light irradiation, with a Lloyd interferometric set-up. The resulting structures were analyzed, from optical point of view, by three methods: white light interferometry (WLI), optical microscopy and diffraction efficiency. All determination has been done in correlations with the irradiation parameters: fluence and number of pulses. We can say that the pulsed radiation interferometric patterning of azo-polysiloxanes is an efficacy and controllable technology to obtain surface relief gratings very necessary for the biological applications (cell culture) and optical methods analyses are useful for rapid determinations.

We investigated experimentally and theoretically the laser ablation of Al by using nanosecond laser-pulses at 532 nm wavelength in atmospheric air. We analyzed experimentally the dependence of the ablation rate on the laser fluence and pulse number. The fluence was varied between 3 and 3000 J/cm2 by changing the laser-energy, while pulse number was varied between 4 and 60 in steps of 4. The optical microscopy data indicate that the ablation rate increases approximately linearly with the 1/3 power of the fluence. For high fluences (hundreds of J/cm2) the ablation rate is demonstrated to be very large (~2 micron/pulse) and approximately constant during 30 consecutive pulses and much smaller during the next pulses. The dependence of the ablation rate on pulse number was further addressed by spectrometric analysis of the ablation-plasmas produced at high fluences. We found that the plasma temperature varies similarly to the ablation rate when increasing the pulse number. The ablation rate in the low fluence regime was addressed theoretically within the frame of a photo-thermal model which accounts for the material heating, melting and evaporation upon laser radiation. The theoretical and experimental results are in good agreement indicating the validity of the model for low laser fluences.

The development of new advanced biomaterials with interesting properties has attracted much more attention in the recent years. This paper presents a new bottom-up approach strategy to design noncovalent entities based on single walled carbon nanotubes (SWCNTs) and artificial lipid membranes (liposomes), with potential biomedical applications (drug delivery systems). Small unilamellar liposomes (SUVs) were prepared by thin film hydration method. Chlorophyll a (Chla) extracted from fresh spinach leaves, was incorporated in liposomes (Chla/lipid molar ratio =1/100) and used as a molecular sensor to monitor the changes occurred in the artificial lipid bilayers. SWCNTs were added to a suspension of Chla-SUVs and then subjected to ultrasound treatment. These nanobiomaterials were investigated by different spectral methods (DLS, UV-VIS absorption and emission). The originality of this work lies in the way of design, preparation and characterization of new nanobiomaterials by CNT biofunctionalization. The use of Chla is also another element of novelty. The spectral properties of Chla were exploited by introducing specific spectral parameters in order to monitor the changes at molecular level and the bionanomaterial time evolution. The biofunctionalization of CNTs with Chla-liposomes could be an effective method to increase CNT biocompatibility and to reduce their toxicity, getting bionanocomposites with biomedical applications.

The aim of the present work is to prepare, test and analyze the electrical and optical characteristics of the p- NiO/n-Si and n-ZnO/p-Si heterojunctions as building blocks in semiconductor devices. p-NiO thin films of 75 nm have been prepared by thermal oxidation of Ni metallic films of 50 nm deposited by e-beam high vacuum evaporation technique on n type silicon wafer with 30 Ω cm resistivity. The oxidation processes of nickel samples are performed at 430^oC for 60 min in a controlled ambient of oxygen and argon maintaining the oxygen concentration of 70%. The structural characteristics observed by X - ray diffraction method showed a polycrystalline structure with strong peaks corresponding to cubic NiO. p-NiO / (n/n⁺) Si heterojunctions I-V characteristics revealed that p-type NiO thin films have been obtained and a value of ~2.2 V for forward threshold voltage. n-ZnO thin layers of about 200 nm thickness, doped with aluminum on 30 Ωcm resistivity p type silicon epitaxial wafers were obtained by spin coating, layer by layer, using zinc acetate (Zn(CH₃COO)₂⋅2H₂O) and aluminum nitrate (Al(NO₃)₃⋅9H₂O) with Al/ Al+Zn ratio in range 0.5 - 1.5 % followed by thermal treatment at 475 °C for 15 minutes. The obtained thin layers have a high transparency T>85% for NiO and >70 % for ZnO:Al) over a large spectral range and a low resistivity, ρ~10^-4 Ωcm. The I-V characteristics of p-NiO/n– Si shows that this heterojunction has rectifying properties with turn on voltage in the range 1.5- 2V and reverse breakdown voltage >10 V. By fitting the forward voltage we have obtained for p-NiO/n-Si a series resistance id R_S=16 kΩ, an ideality factor of >10 and a barrier height of 0.648 eV. The optical response of n-ZnO/p- Si heterojunction was investigated at λ_p = 475 nm and the measured values of the photocurrent about 10 μA confirms the possibility to use them as ultraviolet radiation detectors.

Electronic equipment cooling processes require development of more and more complex systems. In order to achieve adequate cooling, phenomena like Joule Thomson, Peltier or the thermal tube principle are now employed. Correct Central processing unit (CPU) functioning imposes use of efficient heat exchangers. Experimental investigations showed a different behavior for heat radiators, depending on the flow channels configuration and chosen route for the air circulated by the system fan. For the present study, the adopted mathematical model takes into consideration several aspects, such as flow regime, air viscosity, microchannel physical parameters and characteristics of CPU-cooler interface material. Temperature variations in CPU area were analytically calculated starting from a Holman model, completed by resolution of Fourier equations for a stationary unidirectional regime, with parallel flat walls, and internal heat sources. The CPU was assumed to generate all the heat. A CPU cooling system behavior was investigated using a heat transfer model, created in ANSYS, for the above-mentioned conditions.

The present paper proposes a development framework of the nanorobots as functional heterogeneous nanosystems governed by the synergistic integration both at functional and structural levels. The main concept is that of the USIPS (Unified Synergistic Information and Power Signal) that represents both the information and power flows in nanorobots, and is the support for information processing, control, decision, movements and forces generation and application in performing nanorobot’s actions in and/or upon the working environment. Using the USIPS concept, 25 fundamental operations are determined, that integrate the representation of perception, processing, decision and actions. These operations together with the USIPS concept are used to develop at the operational level a nanorobot, but also every nanosystem. Thus, the proposed framework is a design approach that may be considered also as a support for CAD environments for nanorobots and nanosystems in general.

In this paper we present, for a CMOS n-diffusion photodiode, the effects of various doping concentrations on the behaviour of two of the main parameters that characterize the performance of these devices: the photocurrent (for low and for high levels of the illumination) and the dark current. We performed simulations aided by T-CAD tools for each type of layer of the CMOS photodiode structure (substrate, p-epitaxial layer, n-diffusion layer) and evaluated the behaviour of the photocurrent and dark current in various levels of the doping concentrations of these layers. These results may be helpful in the process of fabricating these devices, where controlled amounts of impurities may be added to some layers (or their level might be reduced in some other layers), in order to maximize the photocurrent and to minimize the dark current in these structures.

The success of terrestrial wireless sensor networks in monitoring various phenomena caused an increased interest to develop underwater sensor networks by the underwater acoustics community. These networks are based on underwater acoustic modems for real-time data transmission. The high cost and fixed architecture of these devises makes it impossible to implement dense wireless sensor networks adapted to the environment. We propose an adaptive architecture for a low cost underwater acoustic modem. Designing such a modem with adaptable parameters is determined by the zonal variability of the underwater channel. This article presents the results of a frequency dependent simulation for a particular underwater channel in the Black Sea for which we determined the distance dependent impulse response. The simulation results reinforce the idea of variability of the transmission channel and support the idea of designing an adaptive underwater acoustic modem. Underwater acoustic modem, frequency dependent simulation, underwater wireless sensor network, underwater acoustic channel.

The goal of this paper is to comparatively present the functionality of an achromatic doublet and of the human eye. The comparisons are done using demonstrative images which present the spatial resolution of an image that is considered the tested object. To perform the simulations are presented the models and are computed the point spread functions of the eye and the doublet. Even that the achromatic doublet and the human eye have the same optical configuration, between those two exist big differences in functionality due to the effect of the optical aberrations. In function of the number of the aberrations present in to the human eye the point spread function of the eye can considerably varies from one person to other. Instead the achromatic doublet can focus two rays in the same point and its point spread function remains constant.

The goal of this paper is to simulate the essential process that happens during the scanning of an image. We begin with the scanning of an image. We use a lens that collects the reflected light and then the scanned image is acquisitioned by the CCD sensor. The optics of the scanner introduces the falloff of the irradiance at the edges of the detector. Then we filter the blur introduced by the optics of the scanner and we filter the photon shot noise. At the end of scanning we obtain a halftone image. We correct the halftone image and we JPG compress the image. Finally, the image is saved and then is reproduced on the display.

A REC model (Rate Estimation from Concentrations) numerical procedure was adapted in order to estimate the production rate of selected fatty acids in some mushroom species. The production as well the distribution of these target compounds was evaluated at whole mushroom bodies as well at its different anatomical compartments. These new numerical procedure was tested with some artificial tests as well with multiple real measurements of fatty acids from all anatomical compartments of studied mushroom species. Fatty acids analyses from mushroom samples were done on gas chromatograph-mass spectrometer (GC-MS) system after a derivatization step. The amount of fatty acid methyl esters (FAMEs) from mushroom body samples ranged between 0.5 – 29.4 ng⋅kg^-1 dry weights. Obtained results showed that this adapted numerical approach is optimal to estimate robust and reasonable rate and distribution profiles for relative concentration measurements of fatty acids, uncertainty being no larger than 10 %.

Antenna synthesis can yield optimal radiating structures in terms of pattern diagram, gain, bandwidth or other figures of merit. Although the synthesis might be more difficult for continuous sources than for antenna arrays the resulting radiating structures are cheaper and easy to manufacture. In this paper, we propose a time-domain synthesis approach for ultra-wide band antennas. The method is based on a finite expansion of the antenna time-domain response. The synthesis is performed with regard to the resemblance between the time-domain radiated waveform and the waveform at the antenna input. The approach is validated by synthesizing a planar, ultra-wide band antenna designed for a particular waveform of excitation.

Low-distortion antennas for pulsed excitation can be synthesized by using a technique based on a finite expansion of the antenna time-domain response. Current profiles can therefore be generated in order to achieve optimal response for a given waveform of excitation. However, the simplest radiating structures resulting from synthesis might neither provide acceptable input matching, nor omnidirectional radiation. This paper addresses these two issues and further proposes two antenna structures.

One of the most widely used denoising techniques with well preserving edge features in medical imaging is anisotropic diffusion filtering. It is based on the iterative solving of the diffusion equation that takes into account only the heat propagation by conduction¹. At living beings, blood perfusion represents another important way to transfer the heat. In this case, we used a new equation modeling the heat propagation, mainly Pennes equation², processing both conductive and convective heat components. Unlike heat, white noise, which accompanies the signal detected by a thermal sensor, is not a solution to this equation. The new filtering method consists in an iterative solving of bio-heat equation by using Crank-Nicolson convergent algorithm. Bazan’s criterion for stopping iterations agrees well with the behavior of this filter. The filter was tested on some theoretical models of images simulating different signals and noises, and on many thermal images of healthy people or patients suffering from different types of thyroid disorders. One image processing of a patient suffering from papillary carcinoma is shown at different time moments. The noise is rapid attenuated, and it is possible to assess the contour shape or to locate more outbreaks in a certain area, if any.

Signals with linear frequency modulation are used in synthetic aperture radar to improve spatial resolution and signal/noise ratio. Acoustic field is proposed in this paper to investigate objects, because it could penetrate them, and propagate inside. When input signal frequency is about resonance frequency, the attenuation is increased, and as a result, the scattered acoustic field is decreased as well. So, a linear frequency modulation signal with constant amplitude is sent to the investigated object, and variable amplitude is reflected, corresponding to the object resonance frequencies. A new method for detection the amplitude modulation of these signals in presence of noise is presented. The method uses the fractional Fourier transform in two steps. In the first step a rotation of signal by the angle=45⁰ is done. The all spectral components outside central band are canceled. After that a new rotation of new function with the same angle is done. The simulated results are presented. The method gives good results of amplitude modulation detection for signals with complex modulation signals having signal - noise ratio in power up to - 5 dB. By knowing the resonance frequencies it is possible to specify the largest 3D object dimension, appreciate the relative values of the other dimensions, and do a rough classification of that object. The presented method could be used for rough classification of buried objects in earth or to early diagnose whether a tumor tissue is or not malignant.

The purpose of this paper is to present a new method for evaluation of 3D object shapes which are inside of different environments, and a direct visual contact is not possible. High resolution sensors could solve this kind of problem, mainly by inverse electromagnetic scattering using antenna arrays or synthetic apertures. A cheaper solution is to radiate acoustic field inside of the searched environment. The object detection is realized when the level of received signal exceeds a certain value. The object shape could be appreciated by analyze of 10 consecutive resonant frequencies. Spectral distribution of the resonant frequencies represents the object "signature", and it is related to spatial object dimensions. For a given object, this spectral distribution could show how large the object is, in what way the outer surface is smooth or rough or how large the roughness is. The simulation results for three types of objects: pyramid, sphere, and ellipsoid cavities, smooth and rough are presented. Two roughnesses were selected for each object. The resonant frequencies of different objects could be stored and used for medical application (for instance, diagnosis of a tissue whether it is benign or malignant), mine detection buried in ground or evaluation of the different substances filling up the buried objects.

This paper is trying to provide a guideline to model the spectral output of optoelectronic emitting devices and the spectral responsivity of optoelectronic detectors. The author's work aimed to make the connection between the optical power emitted by LEDs and the wavelength of the radiation emitted, respectively between the photocurrent generated by photodiodes and the wavelength of the radiation received. The goals were to be able to simulate such optoelectronic devices within PSpice from the optical perspective, and to analyze and evaluate the spectral matching of such optoelectronic devices when these are used for example in an optocoupler, or in other kinds of optical coupling.

In the framework of the stochastic approach to the description of the interaction between the quantum dimer nanocluster with two electrons and dissipative environment, such as a weak structured organic matrix, the electron transfer kinetics is theoretically investigated. The minimal theoretical model formulated here involves the applying of Redfield’s theory for the reduced density matrix and the using of Haken-Strobl approximation. The dimer nanocluster is considered in the model “two centers – two electrons”, which is described with using of Hubbard’s Hamiltonian, so that the electron correlation is taken into account. It was found that the difference in the electron populations on the dimer nanocluster centers has an oscillatory time dependence with a beats, which is damping due to the influence of a weak structured matrix as a thermostat. This manifests itself as a change in the nanodimer dipole moment, i.e. during of the relaxation time determined by a dissipative environment holds the switching of nanodimer between the states with the opposite directions of its dipole moment. Eventually, the dimer nanocluster relaxes from an initial state with two electrons on one center to the final state with a uniform distribution of electrons on the centers. It is shown how the switching is modified for the different values of the nanodimer parameters and dissipation parameter. This switching regime in the nanosystem studied here is interesting for various device applications due to the ability to control the state of such nanosystem by action of the external electric and magnetic fields.

The parametric reliability of automatic control system is very important for all systems expose to constraints, uncertainties or possibility of variation in values of some physical parameters that can chance the mathematical model of the system. In this paper we present some models which are able to detect a possible “mission-critical” situation in a complex and critical system like ¹³C (Carbon) Isotope Separation Column. The sensitive aspects which may lead to “mission-critical” situations and relevant to our system are: abnormal changes of the column, the monitored processes, sensors failure, problems regarding the column temperature that has a direct influence on the carbon separation coefficient, and other mechanical or non-mechanical failures from the distillation column.

The basic idea of the used technique is for using stochastic approximation to simulate physical phenomena in the propagation of polarized radiation scattering environment. In the standart modeling only absorbed, missed and reflected photons are calculated, in polarization modeling structural and geometric parameters are noticed. The flowchart contains the basic elements of the standard elements of simulation and calculation with the regard to polarization.

The present and near future lighting solutions will include surely power light-emitting diodes (LEDs). With increasingly power offered by the modern structures, thermal management issues can arise. In this paper we present thermal investigations on three type of power LED, of 1W, 3W and a 10W module. The investigations are oriented in direction of offering trusty suggestions and solutions regarding the thermal regime of discrete LED used as stand-alone or in assembly modules. The temperature will be determined through thermal simulation. The simulation based on finite-element models will bring valuable results, especially for multiple LED modules for which the model with thermal resistance offer only global results, without information of PCB temperature. For the measurements preparation the LEDs are attached to printed circuit boards (PCBs): classic FR4 and metal core PCB (MCPCB). The measurements will be done by combining thermocouples data acquisition system with IR thermovision camera.

This work presents a numerical analysis using the finite difference time domain (FDTD) method of the optical properties (modal characteristics, dispersion, propagation length, and optical confinement) exhibited by a particular class of plasmonic waveguides named dielectric loaded surface plasmon (DLSP) devices. The DLSP systems investigated here consist in ridge like waveguides realized from PMMA with typical cross section areas of 100x100 nm configured on the top of a silver substrate. The FDTD simulations show that in the visible range an optimal compromise between a high degree of optical confinement and an adequate propagation length of around 10 μm can be achieved. This indicates that in this spectral range the proposed DLSP waveguides could possesses applications in various sensing and optical signal processing devices.

Electric propulsion systems employs between main engine and generator engine of electric cars - engine. The mechanical energy supplied by actuators (diesel or turbine) is transformed into electrical energy using generators and mechanical energy is obtained from using propulsion motors. Because of this dual transformation of energy efficiency at rated power plant is lower than conventional propellers operated directly by the main engines. In modern propulsion plants are used as static elements diodes, thyristors, magnetic amplifiers to obtain control features and convenient control. Propulsion systems ordered with static elements are plants that combine the advantages of synchronous generators with DC motor, can make a shortcut in volume and restricted devices without mechanical contact, convenient features especially for the requirements of the ship. Static elements are used for both commands in the rotor circuit and the DC motor excitation which causes the propeller.

This study presents numerical and experimental results concerning a test impeller of a centrifugal pump. From the experimental point of view, the cavitation was visualized at different Inlet Pressure values. Image processing and statistical treatment of the photographs taken at given impeller position allowed to quantify the attached and cloud cavitation extent. A numerical model of 3D cavitating flows, based on the CFD code Fluent 6.1, has been developed to predict the cavitation behavior in the presented model which is considering the entire pump, the impeller and also the casing of the pump, with all its complex geometry and flow parameters. Non-cavitating and cavitating conditions were investigated. Calculations were found to be in good agreement with experimental measurements and visualisations. Experimental and numerical results concerning the pump parameters were investigated. The overall conclusion is the obvious knowledge that the Net Positive Suction Head (NPSH) is indeed affecting the cavitation condition in the centrifugal pumps, having direct impact on the magnitude of static pressures in various locations inside the pump, but is not altering too much the velocities distributions of fluid.