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Tytuł:
A Hepta-band Antenna Loaded with E-shaped Slot for S/C/X-band Applications
Autorzy:
Khan, Imran
Devanagavi, Geetha D.
Sudhindra, K. R.
Ali, Tanweer
Rashmitha, R. K.
Gunjal, Raksha
Powiązania:
https://bibliotekanauki.pl/articles/226788.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
S-band
C-band
X-band
E-shaped slot
current distribution
Opis:
A compact planar multiband antenna operating at 3.1 (S-band) /4.7/6.4/7.6 (C-band) /8.9/10.4/11.8 GHz (X-band) is presented. The proposed Microstrip Patch Antenna (MSPA) consists of a rectangular radiator in which an E-shaped slot is etched out and a microstrip feed line. The E-shaped slot modifies the total current path thereby making the antenna to operate at seven useful bands. No external impedance matching circuit is used and the impedance matching at these bands are solely achieved by using a rectangular microstrip feed line of length 10mm (L6) and width 2mm (W10). The antenna has a compact dimension of and exhibits S11<-10dB bandwidth of about 6.45% (3.2-3.0GHz), 8.5% (4.9-4.5GHz), 7.6% (6.7-6.2GHz), 3.9% (7.8-7.5GHz), 5.7% (9.1-8.6GHz), 1.2% (10.44-10.35GHz) and 2.2% (11.87-11.62GHz). The simulation analysis of the antenna is carried out by using HFSS v.13.0.
Źródło:
International Journal of Electronics and Telecommunications; 2019, 65, 2; 167-174
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the side deflection of the saw band of a joinery band saw influenced by the selected technical and technological factors
Autorzy:
Krilek, Jozef
Kuvik, Tomáš
Kováč, Ján
Melicherčík, Ján
Powiązania:
https://bibliotekanauki.pl/articles/409900.pdf
Data publikacji:
2020
Wydawca:
STE GROUP
Tematy:
band saw
saw band
stability
side deflection
Opis:
The paper focuses on measuring and evaluating the impact of selected technical and technological factors - the height of adjustable guides and stretching force - on the side deflection of the saw band of a joinery band saw. There is a detailed description of the ways the side deflection can be measured. In order to find out the intensity of the stretching force was used portable tension meter SANDVIK 5000, enabling to check the tensile stress in the saw blades of a gang saw or in the saw bands of a band saw. The actual experiment was conducted on a joinery band saw, at the cutting rate vc = 15 m·s-1. The results of the measurements confirmed the theoretical assumption of the impact of the selected technical and technological factors on the stability of the saw band, where the side deflection decreases with increasing stretching force and increases with increasing height of the guides. The stability of the saw band affects the quality of the surface to be treated, thus saving the cost of machining the workpiece and making work productivity more efficient.
Źródło:
Management Systems in Production Engineering; 2020, 3 (28); 148-153
2299-0461
Pojawia się w:
Management Systems in Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laparoscopic adjustable gastric band (LAGB) migration – endoscopic treatment modalities
Autorzy:
Klimczak, Tomasz
Szewczyk, Tomasz
Janczak, Przemysław
Jurałowicz, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/1393748.pdf
Data publikacji:
2016
Wydawca:
Index Copernicus International
Tematy:
LAGB
gastric band erosion
endoscopic removal of gastric band
Opis:
Laparoscopic adjustible gastric binding (LAGB) is one of most common surgical methods of treating obesity. Gastric band migration (erosion) is a typical LAGB complication, with a frequency of about 1-4%. The aim of the study was to present the possibilities of endoscopic diagnosis and treatment of this complication. Material and methods. The study was carried out in the Department of Gastroenterological, Oncological and General Surgery in Łódź. Between 2008 and 2015, 450 gastric bands were implanted using the laparoscopic technique in 318 (71%) women and 132 (29%) men. In this period 7 cases of band migration were diagnosed – 3 cases in men (2.3%) and 4 cases in women (1.3%), what presents 1.56% of general number of complications. Five out of 7 eroded bands were qualified for endoscopic removal. Four out of 5 qualified eroded bands were removed using the gastric band cutting technique. In one case we used the musculo-mucosal incision technique. In order to diagnose early perforations all patients underwent control passage examinations with oral contrast (gastrografin) 3-6 hours after the procedure. Results. All 5 out of 5 qualified eroded gastric bands were successfully removed with the endoscopic method, which gives 100% success rate in own material. Two endoscopic methods were used: 1) endoscopic gastric band cutting, 2) endoscopic musculo-mucosal incision. Conclusions. Endoscopy gives a possibility of instant diagnosis of gastric band migration and early minimally invasive treatment. One of our endoscopic methods of removing the bands by making several incisions of the musculo-mucosal plicae has not yet been described in professional medical literature.
Źródło:
Polish Journal of Surgery; 2016, 88, 6; 530-539
0032-373X
2299-2847
Pojawia się w:
Polish Journal of Surgery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Functional data analysis and its application to local damage detection
Autorzy:
Leśkow, Jacek
Skupień, Maria
Powiązania:
https://bibliotekanauki.pl/articles/1359226.pdf
Data publikacji:
2019-04-25
Wydawca:
Główny Urząd Statystyczny
Tematy:
informative frequency band
Opis:
Vibration signals sampled with a high frequency constitute a basic source of information about machine behaviour. Few minutes of signal observations easily translate into several millions of data points to be processed with the purpose of the damage detection. Big dimensionality of data sets creates serious difficulties with detection of frequencies specific for a particular local damage. In view of that, traditional spectral analysis tools like spectrograms should be improved to efficiently identify the frequency bands where the impulsivity is most marked (the so-called informative frequency bands or IFB). We propose the functional approach known in modern time series analysis to overcome these difficulties. We will process data sets as collections of random functions to apply techniques of the functional data analysis. As a result, we will be able to represent massive data sets through few real-valued functions and corresponding parameters, which are the eigenfunctions and eigenvalues of the covariance operator describing the signal. We will also propose a new technique based on the bootstrap resampling to choose the optimal dimension in representing big data sets that we process. Using real data generated by a gearbox and a wheel bearings we will show how these techniques work in practice.
Źródło:
Statistics in Transition new series; 2019, 20, 1; 131-151
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dual Band Integrated Wideband Multi Resonating Patch Antenna for C–Band and Ku–Band Applications
Autorzy:
Srivastava, Karunesh
Singh, Sweta
Singh, Aditya Kumar
Singh, Rajeev
Powiązania:
https://bibliotekanauki.pl/articles/226214.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
micro-strip antenna
dual-band
wideband
cband
ku-band
HFSS
Opis:
A wideband antenna with dual band characteristic at 5.33/14.3GHz with resonating frequencies for wireless applications is presented. The strategy of the design is to introduce multiband in antenna band. Bandwidth of the antenna increases by embedding annular ring on the radiating patch and four bands are achieved by introducing coupling gap between the patches. Surface current distribution is analyzed at different resonating frequencies for understanding the radiation mechanism and effect of annular ring. The antenna parameters such as return loss, radiation pattern, gain, VSWR and group delay are discussed. The impedance bandwidth of the proposed dual band antenna at lower resonant frequency is 12.7% (simulated) and 9.8 % (measured) whereas at upper resonant frequency is 15.3 % (simulated) and 13.97 % (measured).
Źródło:
International Journal of Electronics and Telecommunications; 2019, 65, 3; 347-352
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Late Band Migration After SAGB. Case Report
Autorzy:
Meissner, Wiktor
Krokowicz, Łukasz
Bobkiewicz, Adam
Drews, Michał
Powiązania:
https://bibliotekanauki.pl/articles/1395676.pdf
Data publikacji:
2015-07-01
Wydawca:
Index Copernicus International
Tematy:
obesity
SAGB
band migration
Opis:
Obesity, a major public health issue of the 21st century, is increasingly common in adults and children. No good results of pharmacological treatment of obesity results in rapid development of bariatric surgery, which treats obesity and comorbidities associated. There are many surgical options for treating obesity. Options for surgical management of morbid obesity include restrictive (adjustable gastric banding, vertical band gastroplasty), restrictive/resective (sleeve gastrectomy), restrictive/malabsorptive (Rouxen-Y gastric by-pass, biliopancreatic diversion with duodenal switch) and purely malabsorptive procedures (duodenal switch). Among them, swedish adjustable gastric banding (SAGB) or laparoscopic adjustable gastric banding (LAGB) have been more frequently performed. SAGB is considered to be safe and effective method of weight loss and elimination of diseases associated with obesity. Laparoscopic gastric banding offers the advantages of minimally invasive surgery, adjustability, and reversibility. Despite fewer number of complications than other bariatric operations, patients after SAGB may have unique complications that are characteristic of the SAGB and require special management and treatment. This paper presents a rare case of complete migration of the band into the gastric lumen.
Źródło:
Polish Journal of Surgery; 2015, 87, 7; 362-364
0032-373X
2299-2847
Pojawia się w:
Polish Journal of Surgery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania eksperymentalne sił działających na zęby piły taśmowej w czasie cięcia różnych gatunków drewna
Experimental research of cutting forces acting on a band saw teeth during cutting various species of wood
Autorzy:
Król, R.
Taraś, A.
Powiązania:
https://bibliotekanauki.pl/articles/310873.pdf
Data publikacji:
2016
Wydawca:
Instytut Naukowo-Wydawniczy "SPATIUM"
Tematy:
piła taśmowa
pilarka taśmowa
obróbka drewna
band saw
band saw machine
wood processing
Opis:
W artykule przedstawione zostały wyniki pomiarów sił, które działają na zęby piły taśmowej podczas cięcia różnych gatunków drewna występujących w Polsce. Ostatnia zaawansowana praca, poświęcona cięciu polskich gatunków drewna na piłach taśmowych opublikowana została przez T. Orlicza w latach sześćdziesiątych ubiegłego stulecia. Obecnie brak jest publikacji zawierających podobne wyniki, zmierzone przy użyciu nowoczesnych metod. W artykule autor przedstawił wyniki pomiarów sił skrawania uzyskane przy użyciu oryginalnego urządzenia składającego się z czujników foliowych, elektronicznego układu Arduino oraz laptopa. Informacje o siłach podczas cięcia drewna są potrzebne przy projektowaniu pił taśmowych i pilarek taśmowych. Znany jest przypadek firmy produkującej piły taśmowe, która zdecydowała się na eksport swoich produktów do Chin i zanotowała straty, ponieważ chińskie drewno odznacza się innymi właściwościami fizycznymi niż gatunki krajowe.
In this paper the results of forces measurement, which act on the band saw teeth during cutting various species of Polish wood was discussed. Since 1960, when T. Orlicz published results of cutting forces measurement, there haven’t been published any comprehensive work which present the similar data measured with modern equipment for Polish species of wood. In this paper, author shows the results which was measured by the original device consisted of film sensors, Arduino electronic board programmed by the author for the film sensor signal sampling and notebook. Knowledge about forces, which act on the band saw teeth during cutting chosen species of wood is necessary in the design of band saw blades and band saw machines. It was known case, when Polish company took in the export of band saws for China and recorded a loss, because the Chinese wood is characterized by different physical properties than domestic species.
Źródło:
Autobusy : technika, eksploatacja, systemy transportowe; 2016, 17, 12; 1092-1096
1509-5878
2450-7725
Pojawia się w:
Autobusy : technika, eksploatacja, systemy transportowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Band structure of ruthenate superconductors
Autorzy:
Dow, J.
Zolotovsky, A.
Powiązania:
https://bibliotekanauki.pl/articles/1934032.pdf
Data publikacji:
2011
Wydawca:
Politechnika Gdańska
Tematy:
band structure
superconductors
transition temperature
Opis:
We investigate the band structure of ruthenates using the first-principles method of density functional theory (DFT). We calculated the band structure and density of states at the Fermi level for superconductors Ba2YRuO6 and Sr2YRuO6. Our calculations show that the maximum critical superconducting transition temperature Tc=93K can be obtained for Ba2YRuO6.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2011, 15, 1; 99-105
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
One-Dimensional Tasaki-Hubbard Model in Paramagnetic Limit
Autorzy:
Baliha, V.
Richter, J.
Derzhko, O.
Powiązania:
https://bibliotekanauki.pl/articles/1030091.pdf
Data publikacji:
2017-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
flat-band Hubbard model
paramagnetism
Opis:
The one-dimensional Tasaki-Hubbard model belongs to the class of flat-band ferromagnets. By introducing an infinitesimally small external magnetic field, we examine the properties of the model in the paramagnetic regime. We compare and contrast them to the properties of the conventional Curie paramagnet.
Źródło:
Acta Physica Polonica A; 2017, 132, 4; 1256-1260
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measuring the dynamic twisting behaviour of saw blades in the kerf during the sawing process
Autorzy:
Albrecht, D.
Stehle, T.
Powiązania:
https://bibliotekanauki.pl/articles/100185.pdf
Data publikacji:
2016
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
band saw
cutting
vibration
measurement
Opis:
Vibrations may occur in all kinds of production processes. Particularly the kinematics of band saws with their thin and unstable structure of the saw blade causes high vibrations, which generate, on the one hand, a high acoustic level. On the other hand, the impact can be seen as grooves on the surface of the workpiece. To optimize the sawing process, the vibration behaviour of the saw blades is investigated by experiment on a test band saw with a contactless measuring system during the sawing process of steel. The focus here is on the twisting of the saw blade in the kerf. The sawing parameters of cutting speed and feed rate are varied here in a wide range to examine the stability of the process and the occurring displacement of the saw blade. The results of this investigation indicate that the saw blade in the kerf shows a characteristic behaviour, which is subject to the cutting parameters. It is obvious that the performance of the process depends not only on the cutting process but also on the tensile state of the saw blade affected by the design of the saw frame, the saw blade guides and the saw blade tension. The results obtained are able to support future developments and identify an optimization potential for the sawing process.
Źródło:
Journal of Machine Engineering; 2016, 16, 3; 75-87
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Review on Multi-dimensional Zinc Oxide Nanostructures
Autorzy:
Acharyya, Sarani
Acharyya, Swarnali
Samanta, Pijus Kanti
Powiązania:
https://bibliotekanauki.pl/articles/1031833.pdf
Data publikacji:
2020
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Band-gap
Morphology
Semiconductor
Zinc Oxide
Opis:
Nanostructured materials are being widely investigated due to their versatile properties leading to promising applications in various areas starting from electronics to environment and medical science. Amongst the various investigated nanostructures, Zinc Oxide (ZnO) is very important because of its versatile properties like high and direct band gap, optical transparency, room temperature ferromagnetism, piezoelectric property and gas sensing property. This mini review article is focused on the morphological study of various ZnO nanostructures starting from hierarchical nanostructures to quantum dots.
Źródło:
World Scientific News; 2020, 147; 140-165
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wybór systemów nagłośnienia pomieszczeń sakralnych
The issue of the choice of sound systems in public worship
Autorzy:
Rosiński, Adam
Powiązania:
https://bibliotekanauki.pl/articles/2138468.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego
Tematy:
sound
church
freqency band
hearing
acoustics
Opis:
The author of the following publication, aware of the shortage of specific literature concerning links between acoustics, architecture and building’s design, sets himself an aim: to depict general problems relevant to architect design of sacred interior reflecting acoustic qualities of each room and to convey useful and basic knowledge to architects, acousticians and clerics referring to the church’s building stage. In the following thesis the most important factors of church’s interior acoustic design are shown because through centuries the discipline caused numerous problems, being difficult to research, recount and neglected. Additional ideas of using natural acoustics of different sacred objects or electro acoustic equipment cause that the following subject area can be adapted in houses of prayer built throughout the years. Therefore the subject of the following article seems to be vitally important and up-to-date because it refers to a specialized field of knowledge of which thorough cognoscence broadens versatility and workshops of the architects, acousticians and clerics, not without influence upon high quality results.
Źródło:
Colloquia Theologica Ottoniana; 2013, 2; 165-183
1731-0555
2353-2998
Pojawia się w:
Colloquia Theologica Ottoniana
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selfadjoint operator matrices with finite rows
Autorzy:
Janas, Jan
Stochel, Jan
Powiązania:
https://bibliotekanauki.pl/articles/1294802.pdf
Data publikacji:
1997
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
selfadjoint operator
band matrix
weighted shift
Opis:
A generalization of the Carleman criterion for selfadjointness of Jacobi matrices to the case of symmetric matrices with finite rows is established. In particular, a new proof of the Carleman criterion is found. An extension of Jørgensen's criterion for selfadjointness of symmetric operators with "almost invariant" subspaces is obtained. Some applications to hyponormal weighted shifts are given.
Źródło:
Annales Polonici Mathematici; 1997, 66, 1; 155-172
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polarization dependent high refractive index metamaterial with metallic dielectric grating structure in infrared band
Autorzy:
Li, Jianmin
Chen, Peng
Fang, Bo
Cai, Jinhui
Zhang, Le
Wu, Yinglai
Jing, Xufeng
Powiązania:
https://bibliotekanauki.pl/articles/2172825.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
metamaterial
high refractive index
infrared band
Opis:
According to the theory of high refractive index of metamaterials, a composite structure of metal dielectric grating was designed to achieve high refractive index in infrared band. Based on the S-parameter inversion algorithm, we extracted the effective permittivity, the effective permeability, and the effective refractive index of the designed metamaterial. By changing the geometric parameters of the composite grating metamaterial structure, the effective refractive index of the designed metamaterial reaches more than 8.0 at the infrared resonance frequency. This is a high refractive index that many natural materials cannot achieve. It is noteworthy that the metamaterial structure has obvious polarization sensitivity. The metamaterial structure has both high refractive index and wideband zero refractive index properties when different polarized light is incident. At the same time, we further investigate the influence of metamaterial geometric parameters on the effective refractive index of metamaterials. Also, we propose a double grating metamaterial structure to obtain more degrees of freedom of metamaterial on the effective refractive index.
Źródło:
Optica Applicata; 2022, 52, 3; 441--460
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ka Band-pass Filter Based on SIW Technology for Wireless Communications
Autorzy:
Damou, Mehdi
Benallou, Yassine
Chetioui, Mohammed
Boudkhil, Abdelhakim
Berber, Redouane
Powiązania:
https://bibliotekanauki.pl/articles/1839462.pdf
Data publikacji:
2021
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
coupling matrix
DGS
filters
Ka band
SIW
Opis:
The paper proposes a new third-order Chebyshev bandpass filter based on the substrate integrated waveguide (SIW) manufacturing technology using an inductive iris and a defected ground structure (DGS) station to resonate in the Ka frequency band, intended for wireless communication applications. All steps that are necessary for designing such a filter have been described in detail based on specific analytical equations harnessed to calculate the different synthesizable parameters of the proposed band-pass filter design, such as the coupling matrix, quality coefficients and initial geometric dimensions. The filter’s ideal frequency response is extracted from an equivalent circuit employing localized elements developed with the use of Design Microwave Office Software. Otherwise, HFSS is employed to set the initial parameters of the proposed topology that will not meet the target specifications defined previously. Accordingly, optimization procedures are necessary for different SIW band-pass filter parameters to reach a high frequency response for the proposed design. The detailed results presented show high efficiency of the SIW technology that offers good performance with lower filter volumes. Two topologies have been developed and then optimized to demonstrate the usefulness of EM software.
Źródło:
Journal of Telecommunications and Information Technology; 2021, 2; 49--56
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Curved-Pentagonal Planar Monopole Antenna for UHF Television Broadcast Receiving Antenna
Autorzy:
Yuwono, R.
Purnomowati, R. B.
Amri, M. Y.
Powiązania:
https://bibliotekanauki.pl/articles/958121.pdf
Data publikacji:
2016
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
planar monopole antenna
television broadcasting
UHF band
Opis:
A planar monopole antenna is an aerial, which the radiating element is perpendicular to the ground plane. It has five equal curvy sides and works at Ultra High Frequency (UHF) band of terrestrial broadcast 478–806 MHz. The curvy sides are made of five equal trimmed ellipses and separated 72o each ellipse to another, form pentagonal shape. Optimizations are obviously necessary to gain the antenna performance at the desired frequency range. The dimensions to optimize this antenna performance are the length of the sides, the offset of curvature, the antenna height from the ground plane, and the ground plane size. Optimization process is done by simulating the proposed antenna with calculated designs using Computer Simulation Technology (CST) Studio Suite 2015 software. The optimized antenna design then fabricated with a 75 W coaxial line fed, measured, and results: Voltage Standing Wave Ratio (VSWR) range of 1.05–1.28, antenna gain at 600 MHz is 15.33 dBi, elliptical polarized, and omnidirectional. With these features, this antenna should satisfy the requirements of UHF television broadcasting.
Źródło:
Journal of Telecommunications and Information Technology; 2016, 3; 103-107
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Sierpinski Carpet Five Band Antenna for Wireless Applications
Autorzy:
Khan, Imran
Devanagavi, Geetha D.
Sudhindra, K. R.
Vandana, K. M.
Pai M. M., Manohara
Ali, Tanweer
Powiązania:
https://bibliotekanauki.pl/articles/226982.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sierpinski carpet
WiMAX
x-band
current distribution
Opis:
A compact Sierpinski Carpet square fractal multiband antenna operating at 3.9 (WiMAX) /6.6 (Satellite TV) /8.1/10.7/11.8 GHz (X-band) is presented. The proposed Microstrip Patch Antenna (MSPA) consists of a Sierpinski Carpet square fractal radiator in which square slots are etched out and a tapered microstrip feed line. The Sierpinski Carpet square fractal patch modifies the current resonant path thereby making the antenna to operate at five useful bands. Impedance matching at these bands are solely achieved by using Sierpinski square slot and tapered feedline, thus eliminating the need of any external matching circuit. The dimensions of the compact antenna is and exhibits S11<-10dB bandwidth of about 4.8% (4.01-3.82 GHz), 2.1% (6.62-6.48 GHz), 2.7% (8.24-8.02 GHz), 2.1% (10.77-10.54 GHz) and 21% (12.1-11.60 GHz) with the gain of 7.57/3.91/3.77/6.74/1.33 dB at the operating frequencies 3.9/6.6/8.1/10.7 and 11.8 GHz, respectively under simulation analysis carried out by using HFSS v.13.0.
Źródło:
International Journal of Electronics and Telecommunications; 2019, 65, 4; 551-556
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modified Groove Coupled Compact EBG Unit Cell as Notch Filter in a UWB Antenna
Autorzy:
Sarmah, Kumaresh
Goswami, Sivaranjan
Sarma, Angana
Baruah, Sunandan
Powiązania:
https://bibliotekanauki.pl/articles/227103.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
EBG
groove feed
UWB Antenna
band notch
Opis:
In this paper, a conventional mushroom-type EBG unit cell is made compact by etching a C-slot at its conducting surface. Further, the C-slotted mushroom-type EBG unit cell is coupled with a microstrip line using a novel groove-coupling technique to design a notch filter. The arrangement has achieved in the reduction of the electrical size of the mushroom type EBG unit cell by 46.15% and create a stop band suppression of -12 dB. The proposed EBG is applied to notch a narrow band centered at 5.2 GHz along with an ultra-wideband antenna. The far field gain of the antenna is suppressed by -5.8 dBi along the direction of its major lobe at 5.2 GHz. The overall size of the antenna system is 19 x 27 x 1.6 mm³ which is compact. The performance of the antenna is validated from the simulation and measured results.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 2; 261-266
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Understanding electron-positron momentum densities in solids : effect of the positron distribution
Autorzy:
Rubaszek, A.
Powiązania:
https://bibliotekanauki.pl/articles/147180.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
positron annihilation
electronic band structure
positron states
Opis:
The influence of the positron distribution on the electron-positron (e-p) momentum densities (MDs) is studied in terms of the l (l = s, p, d, f) character of the initial electronic state. The effect of the positron is discussed for momenta in the extended and reduced zone scheme on the example of Al (simple metal), Cu (metal with almost filled d shell), and Cr (transition metal). Present result indicates a weak sensitivity of the e-p MD inside the central Fermi surface to the positron charge density for the delocalized s and p electrons. In the case of d states, the effect of the positron on the relevant contribution to the e-p MD directly reflects the degree of localization of d electrons in the electron density of states.
Źródło:
Nukleonika; 2015, 60, No. 4, part 1; 759-763
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation of ZnO thin film using sol-gel dip-coating technique and their characterization for optoelectronic applications
Autorzy:
Chaudhary, Preeti
Kumar, Vipin
Powiązania:
https://bibliotekanauki.pl/articles/1075562.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Band gap
SEM
XRD
ZnO
dip coating
Opis:
ZnO thin film with an aim to employ in opto-electronic applications was prepared using sol-gel dip-coating route and thereafter sintered at temperature 500 ºC. The film has been investigated by XRD pattern, SEM, UV-Vis and photoluminescence spectroscopy for physical and optical characterization of ZnO thin film. X-Ray diffraction pattern analysis reveals the polycrystalline nature with hexagonal wurtzite structure having orientation along the plane (002). Scanning electron micrograph shows symmetrical dense ZnO rod throughout the surface. The diffuse reflectance spectrum is studied in the range of wavelength 300-800 nm. A band gap of 3.21 eV is calculated using Kubelka-Munk function. PL spectrum shows strong peak at 380 nm due to oxygen vacancy of ZnO.
Źródło:
World Scientific News; 2019, 121; 59-66
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
History of Semiconductors
Autorzy:
Łukasiak, L.
Jakubowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/308134.pdf
Data publikacji:
2010
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
band theory
laser
Moore's law
semiconductors
transistor
Opis:
The history of semiconductors is presented beginning with the first documented observation of a semiconductor effect (Faraday), through the development of the first devices (point-contact rectifiers and transistors, early field-effect transistors) and the theory of semiconductors up to the contemporary devices (SOI and multigate devices).
Źródło:
Journal of Telecommunications and Information Technology; 2010, 1; 3-9
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recent advances in PBG structures
Autorzy:
Vorgul, I.Yu.
Marciniak, M.
Powiązania:
https://bibliotekanauki.pl/articles/308757.pdf
Data publikacji:
2000
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
photonic band gap
photonic crystals
optical communications
Opis:
We propose a review of word science achievements in the extremely extended for the recent few years field of photonic band gap structures The review concerns both theoretical and experimental investigations on PBG structures toward fabrication of the most optimal ones for different applications. The attention is given to the obtained results as well as to the used and developed methods.
Źródło:
Journal of Telecommunications and Information Technology; 2000, 1-2; 71-76
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Technologia UWB w procesie dystrybucji
UWB technology in the distribution process
Autorzy:
Rzempołuch, M.
Powiązania:
https://bibliotekanauki.pl/articles/2058321.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
dystrybucja
cross docking
Ultra Wide Band
distribution
Opis:
Celem artykułu jest przedstawienie i objaśnienie technologii UWB oraz możliwości jej zastosowania, a w szczególności dla procesu dystrybucji. Przedstawiono model w jakim mogłaby funkcjonować ta technologia w cross dockingu.
The aim of the article is to present and explain the UWB technology and its applicability, in particular for the distribution process. A cross docking model with this technology
Źródło:
Journal of TransLogistics; 2018, 4, 1; 149--156
2450-5870
Pojawia się w:
Journal of TransLogistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Defect modes properties in one-dimensional photonic crystals employing a superconducting nanocomposite material
Autorzy:
Aly, A. H.
Elsayed, H. A.
Malek, C.
Powiązania:
https://bibliotekanauki.pl/articles/173888.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
photonic crystals
band gap
defect mode
nanocomposite
Opis:
In the present work, we investigate theoretically the transmission characteristics of one-dimensional photonic crystals that contain a defect layer of a nanocomposite material in infrared radiation. The theoretical treatment is obtained depending on the fundamentals of the characteristic matrix method. Here, the nanocomposite designed from nanoparticles of a superconducting material is arranged into a dielectric medium. The numerical results clarify the acute effect of the volume fraction and the operating temperature on the effective permittivity of the nanocomposite material. Therefore, the volume fraction, the operating temperature and other parameters such as the permittivity of the dielectric material and the threshold frequency could have a significant effect on the characteristics of the defect modes. Thus, our structure may be very promising in many applications such as narrow band filters and among optoelectronic applications.
Źródło:
Optica Applicata; 2018, 48, 1; 53-64
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of clinic-based and telemonitored home-based intervention on pain intensity, functioning and quality of life in patients with knee osteoarthritis
Autorzy:
Ojoawo, Adesola Ojo
Odesanya, Oluwaseun
Kunuji, Kayode
Mbada, Chidozie Emmanuel
Adedeji, Oluwafemi Olusesan
Powiązania:
https://bibliotekanauki.pl/articles/38695724.pdf
Data publikacji:
2024-03-30
Wydawca:
Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
Tematy:
clinical-based
knee osteoathritis
telemonitored
tera-band
Opis:
Introduction and aim. The study assessed and compared the effects of clinic-based and telemonitored home-based interventions on pain intensity, functioning and quality of life in patients with knee osteoarthritis (KOA). Material and methods. Forty-two patients were recruited purposely and randomly allocated into clinic-based (CBG) and telemonitored home-based group (THG) equally. The CBG and THG received isometric exercises to strengthen the quadriceps and hamstring muscles using theraband. THG received the exercise at home they were monitored on phone thrice in a week, while the CBG did the exercise in the hospital. The subjects performed four sets of eight repetitions three days in a week for eight weeks. Pain intensity, functioning and health related quality of life (HRQoL) were assessed at pretreatment, 6th and 8th week of intervention. Data was analyzed with descriptive and inferential statistics. Alpha level was set at 0.05. Results. There was a significant reduction (p<0.001) among pre-treatment, 6th and 8th week intervention in pain intensity, functional pain intensity and quality of life of CBG and THG. CBG showed significant reduction (p<0.001) in pain intensity, function and increase in HRQoL than THG at 8th week. Conclusion. Clinic-based and telemonitored home-based interventions were both effective in the management of KOA but clinic-based intervention was better than telemonitored home-based intervention.
Źródło:
European Journal of Clinical and Experimental Medicine; 2024, 22, 1; 73-81
2544-2406
2544-1361
Pojawia się w:
European Journal of Clinical and Experimental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł

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