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Tytuł:
Channel Identification Using Chaos for an Uplink/Downlink Multicarrier Code Division Multiple Access System
Autorzy:
Frikel, M.
Safi, S.
Targui, B.
M'Saad, M.
Powiązania:
https://bibliotekanauki.pl/articles/308067.pdf
Data publikacji:
2010
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
channel identification
chaos code
equalization
MC-CDMA system
Opis:
A scheme of chaotic spreading sequence for multicarrier code division multiple access system (MC-CDMA) iproposed to estimate the transmission channel. This systespreads spectrum and identifies the channel, simultaneously. The proposed scheme uses a chaotic sequence generated by a logistic map as a training signal and estimate channel parameters according to dynamics of the chaotic sequence. Encoding data by chaotic sequences is first built and then the orthogonal codes are used to spread the encrypted data for multiusers scheme. At the reception, first the channel parameters are identified using a training chaotic sequence in order to equalize the received data, and then the encrypted information is decoded for the desired user. The studies reveal that the proposed system (chaos plus orthogonal codes) significantly outperforms the Walsh-Hadamard code spreading in MC-CDMA system. The performance of the system is considered in the multiuser case by means of simulation. The simulation result shows that the proposed chaotic code spreading approach for channel identification achieves significant improvement in the channel identification, comparing to using others training sequence or the least square method.
Źródło:
Journal of Telecommunications and Information Technology; 2010, 1; 48-54
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Higher Order Cumulants for Identification and Equalization of Multicarrier Spreading Spectrum Systems
Autorzy:
Safi, S.
Frikel, M.
Zeroual, A.
M'Saad, M.
Powiązania:
https://bibliotekanauki.pl/articles/309082.pdf
Data publikacji:
2011
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
blind identification and equalization
communication channels
higher order cumulants
MC-CDMA systems
Opis:
This paper describes two blind algorithms for multicarrier code division multiple access (MC-CDMA) system equalization. In order to identify, blindly, the impulse response of two practical selective frequency fading channels called broadband radio access network (BRAN A and BRAN E) normalized for MC-CDMA systems, we have used higher order cumulants (HOC) to build our algorithms. For that, we have focussed on the experimental channels to develop our blind algorithms able to simulate the measured data with high accuracy. The simulation results in noisy environment and for different signal to noise ratio (SNR) demonstrate that the proposed algorithms are able to estimate the impulse response of these channels blindly (i.e., without any information about the input), except that the input excitation is i.i.d. (identically and independent distributed) and non-Gaussian. In the part of MC-CDMA, we use the zero forcing and the minimum mean square error equalizers to perform our algorithms. The simulation results demonstrate the effectiveness of the proposed algorithms.
Źródło:
Journal of Telecommunications and Information Technology; 2011, 2; 74-84
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The synergistic effect of piperonyl butoxide on the molluscicidal potential of monoterpenes and phenylpropenes against Theba pisana
Autorzy:
Abdelgaleil, S.A.M.
Saad, M.M.G.
Powiązania:
https://bibliotekanauki.pl/articles/65844.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
synergistic effect
piperonyl butoxide
molluscicidal activity
molluscicidal potential
monoterpene
phenylpropene
Theba pisana
mollusc
white garden snail
sand hill snail zob.white garden snail
white Italian snail zob.white garden snail
Mediterranean coastal snail zob.white garden snail
Mediterranean snail zob.white garden snail
snail
Opis:
The molluscicidal activity of six monoterpenes and two phenylpropenes against Theba pisana adults was evaluated using fumigation and direct contact methods. In the fumigant toxicity assay, (-)-citronellal showed the highest toxicity with LC50 value of 7.79 µl · l−1 air after 24 h of treatment, followed by (-)-terpinen-4-ol (LC50 = 12.06 µl · l−1), (-)-menthone (LC50 = 12.28 µl · l−1 air) and p-cymene (LC50 = 16.07 µl · l−1 air). Eugenol and trans-cinnamaldehyde were the most potent contact toxicants against T. pisana. Their LD50 values were 0.18 and 0.29 mg · snail−1 after 24 h of treatment, respectively. These two compounds were more toxic than a reference molluscicide, methomyl. In contrast, α-terpinene and (-)-citronellal were the least toxic compounds. In another experiment, the synergistic effect of piperonyl butoxide (PBO) on tested monoterpenes and phenylpropenes by topical application was examined. The results showed that the toxicity of the tested compounds was increased when mixed with PBO at a ratio [compound/PBO (1 : 2)] except for α-pinene and (-)-terpinen-4-ol in which the toxicity of binary mixtures was less than for single compounds. The synergistic effect of PBO improved with increased exposure time. The highest synergistic effect was observed with (-)-menthone and α-terpinene with synergistic ratios of 9.25 and 4.37, respectively. Monoterpenes and phenylpropenes and their mixtures with PBO described herein merit further studies as potential T. pisana control agents.
Źródło:
Journal of Plant Protection Research; 2018, 58, 4
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hardness, corrosion behavior, and microstructure of Al-Cu-Mg alloy as a function of 0.3 wt.% Zr addition
Autorzy:
Saad, Karrar
Al-Murshdy, Jassim M. Salman
Powiązania:
https://bibliotekanauki.pl/articles/2174477.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
Al-alloy
effect of alloying element addition
Brinell hardness
current density
recrystallization
stop aluminium
twardość Brinella
gęstość prądu
rekrystalizacja
Opis:
The effect of adding zirconium (Zr) as an alloying element to Al-Cu-Mg alloy on the hardness and corrosion of this alloy was investigated. The hardness and polarization test results of samples treated for various periods by aging at 423.15 K for 3hr showed a significant increment in the Brinell hardness (HBW) improvement ratio of 115.6% (from 45HBW to 97HBW) and an extreme reduction the corrosion rate of the alloy after Zr adding decrease in the current density by 79.42% (from 56.50 µA cm-2 to 11.63 µA cm-2) with aging for 3 hr compared to the base alloy. The impact of this addition is also reflected in the strengthening, recrystallization, and modification of the grain microstructure. These changes were clearly demonstrated by microscopic testing and proves that the addition of Zr has a considerable synergistic effect causing inhibition of recrystallization and refinement of grain size.
Źródło:
Diagnostyka; 2023, 24, 1; art. no. 2023104
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Internal and external top management team (TMT) networking for advancing firm innovativeness
Wewnętrzny i zewnętrzny networking zespołu najwyższego szczebla (TMT) na rzecz rozwijania innowacyjności firmy
Autorzy:
Salleh, S. S. M. M.
Fareed, M.
Yusoff, R. Z.
Saad, R.
Powiązania:
https://bibliotekanauki.pl/articles/405031.pdf
Data publikacji:
2018
Wydawca:
Politechnika Częstochowska
Tematy:
top management team
TMT
networking
firm innovativeness
zespół najwyższego kierownictwa
innowacyjność firmy
Opis:
This research is an attempt to examine the influence of TMT networking on firm innovativeness. Firm innovativeness has been the central concern in the upsurge competitive environment. While strategic decisions, such as, innovation has been posited to be potentially derived by the top management team (TMT), network is in fact a vital medium in providing access to different resources which has been found to be a crucial factor contributing to enhanced judgment and decisions. Despite a surge of studies emphasizing the beneficial of networking as well as examining the role of TMT in explaining the firm strategic decision, there is however little empirical research investigating the influence of TMT networking “internal and external” on firm innovativeness. Therefore, the current study has attempted to fill this gap by surveying 45 TMT leaders representing 45 companies. Findings reveal that TMT internal and external networking has significant impact of firm innovativeness. The study significantly contributes to the Upper Echelon Theory. Further, the study will also benefit the TMT leaders and practitioners as it highlighted the vital contribution of TMT internal and external networking in realizing firm innovativeness.
Niniejsze opracowanie jest próbą zbadania wpływu networkingu TMT na innowacyjność firmy. Innowacyjność firmy była głównym problemem w dynamicznym otoczeniu. Podczas gdy decyzje strategiczne, takie jak innowacje, zostały potencjalnie uzyskane przez zespół najwyższego kierownictwa (TMT), networking jest w rzeczywistości kluczowym medium w zapewnieniu dostępu do różnych zasobów, które okazały się kluczowym czynnikiem przyczyniającym się do lepszego osądu i decyzji. Pomimo wielu badań podkreślających korzyści wynikające z networkingu, a także badania roli TMT w wyjaśnianiu decyzji strategicznej firmy, niewiele jest jednak badań empirycznych badających wpływ networkingu TMT "wewnętrznego i zewnętrznego" na innowacyjność firmy. Dlatego też w niniejszym opracowaniu podjęto próbę wypełnienia tej luki poprzez przebadanie 45 liderów TMT reprezentujących 45 firm. Wyniki pokazują, że wewnętrzny i zewnętrzny networking TMT ma znaczący wpływ na innowacyjność firmy. Badanie znacząco przyczynia się do teorii Upper Echelon. Co więcej, badanie przyniesie również korzyści liderom i praktykom TMT, ponieważ podkreśliło istotny wkład networkingu wewnętrznego i zewnętrznego TMT w realizację innowacyjności firmy.
Źródło:
Polish Journal of Management Studies; 2018, 18, 1; 311-325
2081-7452
Pojawia się w:
Polish Journal of Management Studies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of multi extrusion die process on mechanical and chemical behavior of 2024-T3 alloy
Autorzy:
Razooqi, Ahmed Ibrahim
Abbas, Naseer M.
Ghazi, Sara Saad
Powiązania:
https://bibliotekanauki.pl/articles/2174206.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
wyciskanie
odkształcenie plastyczne
korozja elektrochemiczna
Al 2024-T3
extrusion
plastic deformation
electrochemical corrosion
Opis:
In this paper, a cold multi-pass extrusion process for a 15mm in diameter solid 2024-T3 aluminum alloy rod was carried out using three dies to obtain three different diameters of 14mm, 13mm, and 12mm. The microstructure, hardness, and corrosion behavior were investigated before and after the extrusion process. Load-Displacement data were recorded during each extrusion process. The electrochemical corrosion test was made in a 3.5 wt.% NaCl solution using potentiostat instrument under static potentials test. Corrosion current was recorded to determine the corrosion rate for specimens. The results showed that the extrusion load increased with the number of extrusion passes, which is also seen in hardness test results. In addition, the corrosion rate decreased with the increase in the number of extrusion passes. This is due to severe plastic deformation, which generates a fine grain structure of (AlCu) and (AlCuMg) components.
Źródło:
International Journal of Applied Mechanics and Engineering; 2022, 27, 3; 163--170
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Analysis of Antenna Temperature and Radar Cross Section of Log Periodic Dipole Antenna
Autorzy:
Hamidi, Z. S.
Saad, M. Azren Mat
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/1192599.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Sun
Log Periodic Dipole Antenna
type III
radio region
antenna temperature radar cross section
Opis:
The LPDA antenna because it is very suitable and economic amount the types of antennas. It consists of an array of dipoles in which their lengths and spacing are arranged in a log periodic manner, but not all elements in the system are active on a single frequency of operation. The temperature or Antenna Noise Temperature depends on its gain pattern and the thermal environment that it is placed in. We need to design an antenna that can detect the data and monitor the solar burst type III in radio region. It must be sensitive to a broad frequency range and angular distribution of the incident radio pulse and capable to handle the noise issue that is necessary to gain the pure signal. With large instantaneous bandwidths and high spectral resolutions, these instruments will provide increased imaging sensitivity and enable detailed measurements of the dynamic solar burst. For standardized the time, GPS clock is used to control the sampling time of the spectrometer and a tracking controller control the antenna direction. In conclusion, LPDA is the most practical antennas provide general broadband transmission and reception in a wide range of frequency.
Źródło:
World Scientific News; 2016, 55; 126-136
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The zigzag pattern construction of Log Periodic Dipole Antenna Based on Rumsey’s Principle
Autorzy:
Hamidi, Z. S.
Saad, M. Azren Mat
Shariff, N. N. M.
Monstein, C.
Powiązania:
https://bibliotekanauki.pl/articles/1188094.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Log Periodic Dipole Antenna
zigzag pattern
solar burst
radio region
Rumsey’s principle
Opis:
The log-periodic dipole array (LPDA) consist of an array of dipoles in which there have a different lengths and spacing. The wire may be straight or it may be strung back and forth between trees or walls just to get enough wire into the air; this type of antenna sometimes is called a zigzag antenna. Rumsey’s principle requires that the locations of all elements be specified by angles rather than distances, because of this the log periodic dipole array must be correspondingly longer to get very wide bandwidths and gives a very high data rate transmission. The significance of this study is to understand how do the LPDA can be used to monitor solar activities of the sun using the LPDA antenna. The characteristics that need to be considered during construct this antenna is the radiation pattern, polarization, operation of the frequency band, gain and efficiency of an antenna which indicates the power or field strength radiated in any direction relative to that in the direction of maximum radiation. The arrangement of elements in increasing order from the top of the antenna until the bottom part of antenna. Our designed antenna was constructed using aluminum for the further investigation, we can use a copper and check the difference between two of this element. For this study, we just analyzed the source of RFI using this antenna and for the further analysis, we can use this antenna to monitor the solar burst.
Źródło:
World Scientific News; 2016, 56; 146-157
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Antecedents of psychological capital: The role of work design
Autorzy:
Sameer, Yomna M.
Mohamed, Ahmed Amin
Mohamad, Mohamad Saad
Powiązania:
https://bibliotekanauki.pl/articles/522078.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Tematy:
Job characteristics
Psychological capital
Task performance
Opis:
Aim/purpose – Though psychological capital has become a hot topic in the recent years, scholars have given little attention to its antecedents. This study used the job characteristics model (Hackman & Oldham, 1975) as a framework to examine the relationship between the five job characteristics and the four components of psychological capital. Moreover, task performance is examined as an outcome of psychological capital. Design/methodology/approach – Using structural equation modelling, data were obtained from Egyptian professionals (N = 251). The survey included measures of psychological capital and job characteristics as well as task performance, which was rated by employees’ supervisors. Findings – Results indicate that the five job characteristics of skill variety, task significance, job feedback, job identity and job autonomy are positively related to the four components of psychological capital. Moreover, hope, self-efficacy and resilience were positively related to task performance. However, Egyptian employees’ optimism was not found to be related to task performance. Research implications/limitations – Results contribute to a better understanding of what enhances psychological capital in the workplace. Originality/value/contribution – The current study is the first to integrate the theory of work design with the psychological capacities of hope, optimism, resilience and self- -efficacy. Research on the development of psychological capital has been limited to interventions with little or no attention given to macro or organisational factors that could contribute to its enhancement. Moreover, it is the first to link psychological capital to job performance in an Arab country.
Źródło:
Journal of Economics and Management; 2019, 35; 124-149
1732-1948
Pojawia się w:
Journal of Economics and Management
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coffee grounds as a soil conditioner: effects on physical and mechanical properties - II. Effects on mechanical properties
Autorzy:
Bedaiwy, M.N.A.
Maksoud, Y.S.A.
Saad, A.F.
Powiązania:
https://bibliotekanauki.pl/articles/971314.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
coffee grounds
mechanical properties
soil amendments
soil conditioners
Opis:
Applying coffee grounds (CG) to sandy, calcareous, and clayey soils resulted in notable effects on soil expansion, cracking, cohesion, internal friction, initial stress and resistance to penetration. In sand, expansion upon saturation was greater after wetting-and-drying cycles. Highest increases were 15.71%, 16.14% and 31.86% for sandy, calcareous and clayey soils, respectively. Effect of CG on cracking was negligible in sand and very slight (<1.0%) in the calcareous soil but marked in clay (14.18% at 10% CG). In sand, cohesion (c) increased significantly with CG up to the 10% content. Cohesion increased by 2.5-folds and 4.5-folds at 5% and 10% CG, respectively. The presence of fine CG grains among larger sand particles, boosted microbial activities, and the resulting cementing and binding effects resulted in increased cohesion. For calcareous soil, cohesion rose from 0.04 kg·cm⁻² to 0.13 kg·cm⁻² as CG increased from 0% to 15%. In clay, maximum cohesion (0.20 kg·cm⁻²) was associated with the 10% CG and was highest of all soils. In sand, the angle of internal friction (φ) decreased notably as CG increased from 5% to 10% but there was no consistent pattern in any of the soils. An increase in initial stress (pi) was observed between 0% and 10% CG in sand and between 0% and 15% in calcareous soil while clay showed no particular trend. Patterns of pi were, thus, consistent with those of cohesion for all soils. Resistance to penetration increased substantially with CG in sand. The effect in calcareous and clayey soils took an opposite trend to that of sand and resistance was generally higher in calcareous soil. Overall effects of CG on resistance were desirable in all soils as far as agriculture (seedling emergence, crop growth, irrigation, etc.) is concerned.
Źródło:
Polish Journal of Soil Science; 2019, 52, 2; 277-294
0079-2985
Pojawia się w:
Polish Journal of Soil Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coffee Grounds as a Soil Conditioner: Effects on Physical and Mechanical Properties - I. Effects on Physical Properties
Autorzy:
Bedaiwy, M. Naguib A.
Abdel Maksoud, Y S
Saad, A F
Powiązania:
https://bibliotekanauki.pl/articles/762799.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
coffee grounds
physical properties
soil amendments
soil conditioners
Opis:
Coffee grounds (CG) improved some soil physical properties (dry density, gd; porosity, n; aggregation; hydraulic conductivity, Ks; and infiltration rate, IR). Effects on other properties were inconsistent (e.g., sorptivity, S), or unfavorable (e.g., available water, AW). gd decreased and n increased with CG. CG decreased Ks in sand. In calcareous soil, maximum increase was associated with 10% and 15% CG before and after wetting-and-drying cycles (WDC), respectively. Ks increased with CG in clay, with greatest increase attained at 10% CG. IR decreased with CG in sand. In calcareous and clayey soils, IR decreased with CG before WDC but increased after WDC where maximum increase in clay was linked to 10% CG. No solid trends of soil sorptivity, S, were identified. Before WDC, S had the order: sand > calcareous > clay. For most cases, adding CG increased total water holding capacity (WHC). However, after WDC, the increase in water content at field capacity (FC) with CG was accompanied by a greater increase in wilting point (WP) and therefore a decrease in AW. CG improved soil structure and aggregation and increased non-water-stable aggregates in calcareous and clayey soils. Mean weight diameter (MWD) indicated increase in water-stable aggregates in sand at 5% and 10% CG. In clay, MWD increased only at 5% CG. Although results did not show coherent responses with some tested properties, they, mostly, indicate some beneficial effects of CG, particularly in relation to improving aggregation and water flow.
Źródło:
Polish Journal of Soil Science; 2018, 51, 2
0079-2985
Pojawia się w:
Polish Journal of Soil Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study of pollution and simulation on insulators using COMSOL® under AC voltage
Autorzy:
Benguesmia, Hani
Bakri, Badis
Khadar, Saad
Hamrit, Fareh
M’ziou, Nassima
Powiązania:
https://bibliotekanauki.pl/articles/327338.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
insulator
flashover
pollution
high voltage
potential
electric field
izolator
przeskok
wysokie napięcie
pole elektryczne
potencjał
Opis:
The flashover of pollution, observed on the insulators used in high voltage transmission, is one of the most important power transmission stakes. It is a very complex problem due to several factors including the modelling difficulties of complex shapes of insulators, different pollution densities at different regions, non-homogeneous pollution distribution on the insulator surface and unknown effect of humidity on the pollution. In the literature, some static and dynamic models have been developed by making some assumptions and omissions to predict the flashover voltages of polluted insulators. This paper aims to experimentally analyse the flashover process and simulation of the distributions of the potential and the electric field under 50 Hz applied voltage on a real model simulating the 175CTV outdoor insulators largely used by the Algerian Company of Electricity and Gas (SONELGAZ). This real model is studied under non-polluted (distilled water), and polluted (distilled water and sand) environments. The simulations were carried out by using the COMSOL multiphysics software. This program uses the finite element method to solve the partial differential equations that describe the field. Experimental results made in the laboratory and simulation results are original and found to be congruent.
Źródło:
Diagnostyka; 2019, 20, 3; 21-29
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Complex Signal Mapping for Improving Spectral Efficiency of Li-Fi Systems
Autorzy:
Sileh, Ibrahim K.
Abdulkafi, Ayad A.
Hussein, Mohammed K.
Hardan, Saad M.
Powiązania:
https://bibliotekanauki.pl/articles/958061.pdf
Data publikacji:
2019
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
Li-Fi
OFDM
signal mapping
PAPR
BER
Opis:
Light fidelity (Li-Fi) systems based on the orthogonal frequency division multiplexing (OFDM) scheme have gained more attention in the communications circles, as a means to provide high spectral efficiency and ensure stricter data rate requirements for visible light communication (VLC) systems. However, common OFDM schemes employ Hermitian symmetry to obtain a real-valued signal which is necessary in intensity modulation and direct detection (IM/DD) optical systems, at the expense of doubling the required bandwidth. In this paper, a novel transmission scheme for an OFDM-based Li-Fi system is proposed to tackle the issue in question. A new approach to complex signal mapping (CSM), based on the pairing function method, has been developed for Li-Fi systems. It does not require Hermitian symmetry and, hence, saves about 50% of the required bandwidth. Unlike existing OFDM-based VLC approaches, the proposed scheme employs CSM to ensure a real and positive signal without Hermitian symmetry in order to fully utilize the bandwidth available to Li-Fi networks. Simulation results show that the proposed scheme significantly outperforms other systems in terms of spectral efficiency. The CSM-OFDM based Li-Fi system also achieves a good peak-to-average power ratio (PAPR) reduction with acceptable bit-error-rate (BER) performance, compared to conventional approaches.
Źródło:
Journal of Telecommunications and Information Technology; 2019, 3; 58-62
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laser stimulated nonlinear optics of Ag nanoparticle-loaded poriferous TiO2 microtablet
Autorzy:
Nafisah, S.
Saad, S. K. M.
Umar, A. A.
Plucinski, K.
Lis, M.
Maciaga, A.
Miedzinski, R.
Powiązania:
https://bibliotekanauki.pl/articles/173662.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Ag-loaded poriferous TiO2 microtablets
photoinduced second harmonic generation
Opis:
The studies of the photoinduced second harmonic generation were performed for the Ag-loaded poriferous TiO2 microtablets deposited on an ITO substrate. The poriferous TiO2 microtablets on a pre-cleaned ITO substrate (Kaivo, China, sheet resistance of ca. 10 Ω/square) were prepared by simply immersing the ITO substrate vertically into the growth solution that contains 5 ml of 0.5 M (NH4)2TiF6 (Sigma-Aldrich) and 5 ml of 1.0 M H3BO3 (R.M. Chemicals) for 15 h at room temperature. The samples were obtained from the growth solution with concentration of 0.4, 0.5 and 0.6 M. We have found that maximal second harmonic generation signal was achieved for the samples with concentration 0.5 M.
Źródło:
Optica Applicata; 2015, 45, 2; 263-271
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Green synthesis of thioxoimidazolidine derivative ligand: Spectroscopic, thermal and biological assignments of new Cu(II), Co(II), and Ni(II) chelates in neutral system
Autorzy:
Alosaimi, Abeer M.
Saad, Hosam A.
Refat, Moamen S.
Al-Hazmi, Ghaferah H.
Powiązania:
https://bibliotekanauki.pl/articles/1849315.pdf
Data publikacji:
2021
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Imidazolidine
Microwave irradiation
Coordination
Biological activity
Opis:
Eco-friendly synthesis of ethyl 3-(4-oxo-3-(1-(pyridin-3-yl)ethylideneamino)-2-thioxoimidazolidin-1-yl)propanoate (4) ligand (L) using microwave irradiation technique was described. The structure of thioxoimidazolidine derivative ligand compound has been established based on different types of analyses such as infrared, 1H-NMR, 13C-NMR, and mass spectra as well as elemental analysis. The copper, cobalt, and nickel(II) complexes with molecular for-mula [M(L)(H2O)4]Cl2 (where M = Co(II), Ni(II), and Cu(II), L = thioxoimidazolidine derivative ligand), have been prepared and well-characterized using microanalytical, conductivity measurements, magnetic, spectroscopic, and physical analyses. Upon the outcome results of analyses, the stoichiometry of the synthesized complexes is 1:1 (M:L). The molar conductance values concluded that the behavior of metal complexes was electrolytes. The 3-(4-oxo-3-(1-(pyridin-3-yl)ethylideneamino)-2-thioxoimidazolidin-1-yl)propanoate chelate acts as a monovalent bidentate fashion via nitrogen and oxygen atoms of both thioxoimidazolidine and propanoate ester moieties. The geometric structures of the synthesized metal complexes are an octahedral confi guration based on spectroscopic and magnetic moment studies. The thermogravimetric assignments deduced that the presence of four coordinated water molecules. The synthesized copper(II), cobalt(II), and nickel(II) complexes were biologically checked against G+ and G- bacteria and two species of fungi (Aspergillus Nigaer, and Penicillium Sp.).
Źródło:
Polish Journal of Chemical Technology; 2021, 23, 3; 1-9
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 21

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