Fractal Geometry: An Attractive Choice for Miniaturized Planar Microwave Filter Design

Various fractal geometries are characterized by the self-similarity and space-filling properties. The space-filling feature has been successfully applied to design multiband antenna structures for a wide variety of multifunction wireless systems. On another hand, the second feature has proved its validity to produce miniaturized antennas and passive microwave circuits including the band-pass filters (BPF). This chapter demonstrates the design of miniaturized microstrip BPFs that are derived from fractal-based DGS resonators. Many microstrip BPFs based on the Minkowski fractal DGS resonators will be presented together with those based on Moore and Peano fractal geometries. Simulation results, of all of the presented BPFs, show that an extra-size reduction can be obtained as the iteration level becomes higher. Measured and simulated results agree well with each other. A comparison has been conducted with other filters based on Peano and Hilbert fractal geometries. The results reveal that the proposed BPF offers acceptable performance and a significant decrease of higher harmonics

Extracting dualband antenna response from UWB based on current distribution analysis

An entirely new design approach has been employed to create the printed dualband monopole antenna that was the subject of this investigation. The printed monopole antenna construction is the primary component of the suggested design. CPW transmission lines with 50 Ohm impedance and a relative dielectric constant of 4.6 were used to power the antennas, which were housed in thin substrates with thicknesses of 1.6 millimeters (mm). In this study, the antennas discussed were modeled and analyzed by Computer Simulation Technique (CST) simulator. Using fractal structures on the radiating element of a dualband antenna can improve the resonance of the antenna as well as the coupling of the resonating bands that emerge from the resonance

N-doped TiO2 synthesised via microwave induced photocatalytic on RR4 dye removal under LED light irradiation

Nitrogen doped titanium dioxide (N-doped TiO2) was synthesized by microwave using urea as nitrogen sources with commercially available TiO2-P25. The N-doped TiO2 was compared with unmodified TiO2 by carrying out the investigation on its properties using x-ray diffraction (XRD) analysis, Brunauer-Emmett-Teller (BET), Fourier transformed infrared spectroscopy (FTIR) and diffuse reflectance spectroscopy (UV-Vis DRS). The photocatalytic activities of N-doped TiO2 and unmodified TiO2 were studied for photodegradation of reactive red 4 (RR4) under light emitting diode (LED) light irradiation. An active photoresponse under LED light irradiation was observed from N-doped TiO2 with 60 min of time irradiation to complete RR4 color removal while no photocatalytic degradation was observed from unmodified

Design of Compact Hilbert Microstrip Bandpass Filter For Modern Wireless Communication Systems

This paper presents a new microwave narrow-band bandpass filter with aminiaturized size for use in modern wireless communication systems. Theproposed filter design topology is based on a single-mode microstrip resonatorconstructed in the form of Hilbert fractal geometries from 2nd to 4th iteration levels.The space-filling property the proposed filter topologies possess, has found toproduce reduced size structures corresponding to the successive iteration levels.Many filters have been designed for the Industrial Scientific Medical band (ISMband) applications at a design frequency of 2.4 GHz using a substrate with adielectric constant of 10.8 and thickness of 1.27mm. The performance of each ofthe resulting bandpass filter structures has been analyzed using a method ofmoments (MoM) based software package, Microwave Office 2007, fromAdvanced Wave Research Inc. Results show that these filters possess goodtransmission and return loss characteristics, besides the miniaturized sizes gained;making them the design specifications of most of wireless communication systems

Rheumatoid peripheral blood phagocytes are primed for activation but have impaired Fc-mediated generation of reactive oxygen species

Significant levels of circulating immune complexes (ICs) containing rheumatoid factors and immunoglobulin G in peripheral blood are a characteristic feature of rheumatoid arthritis (RA). ICs interact through Fcγ receptors (FcγR) to activate phagocytes in numerous inflammatory processes. The high concentration of neutrophils in synovial fluid during active phases of the disease, together with their destructive capacity, pose important questions as to their role in the pathogenesis of RA. Functional defects in RA or control peripheral blood neutrophil FcγRs were examined with a specific FcγR-mediated reactive oxygen species (ROS) assay. Heterologous cross-linking of FcγRIIa and FcγRIIIb on neutrophils resulted in a significantly decreased production of ROS by RA cells compared with controls matched for age and sex. However, expression and homologous ligation of receptors did not differ between these groups. These data suggest that neutrophil priming does occur before emigration into the joint and that blood neutrophils from patients with RA have a functional impairment in cooperative FcγR-mediated ROS generation. This may account for the increased susceptibility to bacterial infection that arises in patients with severe disease

Design and implementation of microstrip rotman lens for ISM band applications

This work presents the design and implementation of Rotman lens as a beam steering device for Industrial, Scientific, and Medical (ISM) applications. 2.45 GHz is considered as a center frequency design with (2-6) GHz frequency bandwidth. The beam steering is examined to cover ±21o scan angle with maximum main lobe magnitude 10.1 dBi, rectangular patch antennas are used as radiation elements to beam the output far field. The work is extended to compare between the tapered line which is used for matching between 50-Ω ports and lens cavity. CST microwave simulation studio results show that the rectangular taper line can yield 2 dB return loss less than linear taper line with a little bit shifting in responses for same input and load impedance

Pharmacological characterization of the excitatory ‘Cys‐loop’ GABA receptor family in Caenorhabditis elegans

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136449/1/bph13736.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136449/2/bph13736_am.pd

A Review article of Streptococcus pyogenes infection: Rick factors, prevention and management strategies

Background:-Streptococcus pyogenes is an exclusively human pathogen. This bacterial species is responsible for a large variety of infections. Objective: This review identified published articles on the risk factors, prevention and control strategies for streptococcus diseases. Material and methods: A systematic search was carried out to identify papers published on the Web of Science, PubMed, Scopus, and Google Scholar electronic databases in an attempt to provide basic information about Streptococcus infections, potential risks for their spread, and treatment and prevention strategies. Results: The more common methods for Streptococcus pyogenes transmission are through respiratory droplets, skin lesions brought on by Streptococcus pyogenes contact with infected objects or devices. Another potential mode is foodborne transmission but more research is needed to determine this infection route. Native communities, and those of low socio-economic status worldwide were found particularly susceptible to Streptococcus diseases, as well as children, older adults and those with impaired immune system. Those groups are susceptible to Streptococcus pyogenes infections and their complications with higher infectious rates in educational institutions, hospitals, over-crowding and the continuous increase in social contact. The importance of improving living conditions and personal and hand hygiene is one of the techniques in the management and prevention of Streptococcus pyogenes infections. Infection control methods must be highlighted with greater precision. Conclusion: Prevention and control measures should target the improvement of living conditions, and personal and hand hygiene. Adherence to infection prevention and control practices should be emphasized in high-risk settings

Plane Flow Analysis for a Profile Extrusion Die Using Digital Image processing Technique

This paper investigates the applicability of the proposed digital image correlation (DIC) system instead of traditional method by microscope to measure the strains in forward extrusion process, which conducted for rectangular section with plane strain condition by using taper die at angle (2 = 90 ̊) and the proportion of reduction in area is (42.85 %). Commercial pure lead (99.99% Pb) was chosen as a typical pattern to measure the strain and strain rate for the forward extrusion process by a visio-plasticity technique and the proposed digital image correlation system. The obtained results indicate that the proposed digital image correlation (DIC) system is an accurate and reliable for measuring the strains using inexpensive equipment

A Multiband Fractal Dipole Antenna for Wireless Communication Applications

mmunication applications. The proposed fractal antenna design is based onfractal geometry of the second level tent function transformation. Due to theresulting geometrical structures of a fractal tent function curve depend on thestarting angles of the initial tent function, many dipole antennas have beenmodeled and the corresponding radiation characteristics have been evaluated.Theoretical performance of these antennas has been calculated using the methodof moments (MoM) electromagnetic simulator, IE3D. Simulation results of manytent fractal dipole antennas which have been modeled show that all of theseantennas have multiband resonate behavior, but this resonate behavior is differentaccording to the starting angle for each antenna. The results have shown that theseantennas have acceptable performance for VSWR ≤ 2 (return loss ≤ -10 dB),using a 50W feed line, at most of the resonating frequencies. This feature providesantenna designer with more degree of freedom, and makes the proposed antenna(or its monopole counterpart) suitable for use in the modern multi-functionscommunication system