Alexander Shulzinger

Preparation of Se-doped polyaniline emeraldine base films

Abstract Our letter focuses on the preparation of polyaniline emeraldine base films doped with selenium. PANI EB and Se were dissolved in dimethylsulfoxide. Thin films of selenium-doped PANI EB were obtained by spin-coating of Si and ZnSe substrates with a PANI EB+Se solution in DMSO. We studied the distribution of the selenium in the PANI EB films using time-of-flight secondary ion mass spectrometry (TOF-SIMS). The IR spectra of these thin films were obtained with an FT-IR spectrometer.

Portable Passive Millimeter-Wave Sensor for Detecting Concealed Weapons and Explosives Hidden on a Human Body

This paper describes a portable passive millimeter-wave sensor designed for remote detection of both metallic and non-metallic objects hidden on a human body under cloth. The sensor is based on a directly detection and analyses of the energy emitted by a human body. The algorithm of detection estimates unimodality features of traces recorded in the process of a manual scan. The sensor demonstrates a detection probability in the laboratory environment close to 100% at a distance of up to 3 m for the tested samples of explosives and metal objects hidden under cloth.

Bandpass varactor tunable filters using step impedance resonators

A bandpass varactor tunable filter has been designed to operate from 1 to 2 GHz. In order to expand the tuning range and stabilize bandwidth, step impedance resonators with L and T coupling sections are suggested. As an illustrative example, a 2/spl times/AMP/spl times/2 order filter, tuned within 50% and having almost constant bandwidth, is reported. Integrating such a filter with a low-noise MMIC amplifier has allowed zero insertion loss to be realized.

Resonance absorption of coherent infrared radiation by thin polypropylene films and its technological applications

Abstract Tunable CO2 and non-tunable CO2 lasers were used for the irradiation of thin polypropylene films. The wavelength of the IR radiation was adjusted in such a way that it coincided exactly with the absorbance peak in the spectrum of the polypropylene pattern. In this way, conditions of resonance absorption of IR radiation by polymer films were produced. Strong thermal effects in PP were observed under irradiation at the resonance wavelength. The threshold value of IR power, which causes thermal phenomena in irradiated films was established. We pulled films exposed to established threshold values with a constant speed in the plane normal to the laser beam. Highly developed relief and thin traces were formed depending on the pulling speed. Traces with a width smaller than the wavelength of the incident laser beam were obtained. The IR spectra of irradiated PP films were studied with a FTIR spectrometer. Changes in the spectra of PP films were established using correlation analysis of spectral data. The phenomenon could be applied for obtaining highly developed surface relief, storage of information in polymer films and welding of polymer materials.

Attenuated Total Reflectance (ATR)-FTIR spectral measurements in MIR and FIR (THz) range

Mid-Infrared (MIR) spectroscopy is an extremely reliable and well recognized fingerprinting method. Far-Infrared (FIR) and THz spectroscopy is quite difficult since it requires special sources, quasi optics, special materials and sensitive detectors. The technique of Attenuated Total Reflectance (ATR) has in recent years revolutionized solid and liquid sample analyses because it combats the most challenging aspects of infrared analyses, namely sample preparation and spectral reproducibility. An attenuated total reflection accessory operates by measuring the changes that occur in a totally internally reflected infrared beam when the beam comes into contact with a sample. In this work a spectral measurements using the ATR-FTIR technique will be presented. Spectral measurements of liquids and powders in the THz regime will be discussed and analyze. Furthermore, we will present ATR-FTIR spectral measurements that were carried out for commercial companies.

Development of a novel composite based on polyethylene and low-melting-point metal alloy

This work presents the novel composite material based on a polymer (LDPE) and metal alloy, which have a close melting point. The process of blending the main components of the composite was developed using the extrusion mixing. The process of extrusion of composite films with a thickness 50- 300 micrometers was worked out using an extruder equipped with a cast film die. This process allowed production of the binary composite, with up to 15 wt. % of the alloy dispersed uniformly in the polymer matrix. It was shown that carbon black is highly compatible with the basic components and could be dispensed uniformly in the obtained films. The structure of the composite films was studied with a scanning electron microscope. Physical properties of the binary and ternary composites were investigated, including conductivity and temperature dependence of the thermal capacity. Non- ohmic behavior of the ternary composites was revealed. The IR spectra of the composites were studied using an FTIR spectrophotometer. It was shown that processing polyethylen in the presence of a low-melting-point alloy causes changes in the structure of polyethylene. The presence of alloy caused intensive oxidation of carbon black in the ternary composite as well.

Passive non-imaging mm-wave sensor for detecting hidden objects

The paper presents the results of design and testing non-imaging mm-wave sensor aimed for remote detecting contrabands hidden on a human body under cloth. It operates in passive direct receiver mode at the range 80-100GHz. The unimodality approximation has been suggested for applying in the algorithm of detection. The antenna system of the sensor is based on horn antenna integrated with focusing dielectric lens. The sensor has demonstrated detection probability up to 100% in laboratory environment for the tested samples both plastics and metals hidden under cloth at the distance up to 3m with spatial resolution about 5cm.

Polyethylene films doped with EU(III) complex: their optical properties and technological applications.

Light-converting polyethylene film containing Eu(III) complex with phenanthroline was manufactured under an extrusion process. The film was characterized by means of time-of-flight secondary-ion-mass spectrometry (TOF-SIMS), ultraviolet-visible-infrared (UV-Vis-IR) spectroscopy, study of excitation and luminescence spectra, quantum yield and lifetime of luminescence. TOF-SIMS surface mapping showed the uniform distribution of Eu(III) over the film. Typical Eu(III)-phenanthroline complex excitation and fluorescence spectra were recorded, the quantum yield of fluorescence being 5±2%. Luminescence lifetime was measured as 0.4 ms. Visualization of strong subpicosecond UV laser beams through the use of developed film has been demonstrated.

Real time detection and recognition of micro-poisons in aqueous solutions and atmosphere using perfect absorber metamaterial in millimeter wavelength regime

In this study we present a concept of real-time and very inexpensive sensor for detection and recognition of micro poisons in aqueous solutions. The method is based on combination of advanced millimeter Wavelength (MMW) spectroscopy system and perfect absorber metamaterial (MM). The designed absorption line of the perfect absorber MM moves slightly due to substance presents in vicinity to the perfect absorber. This change is measured by a high-resolution and sensitive MMW spectroscopy system.