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1.
Heliyon ; 10(5): e27393, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38495203

RESUMEN

This paper introduces a compact Multiple Input Multiple Output (MIMO) Ultrawideband (UWB) antenna seamlessly integrated with the Ku band, tailored for wireless communication applications. The MIMO antenna employs octagonal radiators, crafted from a tapered microstrip line-fed rectangular patch, etched on an economically efficient FR4 substrate measuring 40 × 23 mm2. The octagonal configuration is achieved by introducing a rectangular patch to the central radiator, while parasitic stubs are strategically employed to mitigate coupling among MIMO elements. The antenna demonstrates an extensive operational bandwidth spanning 3.28-17.8 GHz, covering UWB, extended UWB, and Ku-band spectrums globally allocated for heterogeneous applications. With a peak gain of 4.93 dBi and an efficiency of 95.34%, the proposed MIMO antenna showcases superior performance. Key performance parameters, including a low envelope correlation coefficient (ECC) of 0.003 and a substantial diversity gain (DG) of 9.997 dB, are thoroughly analyzed. Comparative assessments against recent works validate the novelty and potential of the proposed antenna for integration into compact wireless systems. This study underscores the success of the antenna design in achieving a harmonious balance of compactness, wide operational bandwidth, and high performance, positioning it as a promising candidate for diverse wireless communication applications.

2.
Phys Chem Chem Phys ; 22(7): 3990-3998, 2020 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-32022088

RESUMEN

Materials with moderate bandgap, high carrier mobilities and high thermoelectric efficiencies show robust performance in microelectronic and thermoelectric applications. We investigated the structural, electronic and thermoelectric properties of Si-based group IV-V monolayers using density functional theory and the semi-classical Boltzmann transport theory. The electronic band structure of SiX monolayers calculated with the PBE functional indicates moderate band gap characteristics. All the studied systems are indirect band gap semiconductors except for SiBi. The electronic band gap of these monolayers increases initially up to a certain limit and then decreases, becoming metallic at higher strain. This suggests the possibility of tuning the electronic band gap by applying strain. Carrier mobility is calculated using the deformation potential theory to get the relaxation time. Remarkable values of carrier mobility indicate p-type semiconducting nature for SiN, SiP and SiBi, while SiAs and SiSb indicate n-type semiconducting nature. The maximum ZT values at 300 K of n-type SiSb and SiAs are 1.01 and 0.98, whereas for p-type SiN, SiP, and SiBi they are 0.99, 0.98, and 0.94, respectively. Higher Seebeck coefficients, higher power factors, and a lower value of electronic thermal conductivity could be achieved in these binary compounds. These findings indicate that the new two-dimensional hexagonal SiX (X = N, P, As, Sb, and Bi) systems are promising candidates for thermoelectric materials at room temperature.

3.
Artículo en Inglés | MEDLINE | ID: mdl-24109313

RESUMEN

In the title compound, C15H21ClN2OS, the central chromophore moiety (C2N2OS) is approximately planar, with a maximum deviation of -0.027 (1) Å, and is oriented at a dihedral angle of 86.7 (1)° with respect to the chloro-phenyl ring. An intra-molecular N-H⋯O hydrogen bond stabilizes the mol-ecular conformation. In the crystal, mol-ecules associate via N-H⋯S hydrogen bonds, forming inversion dimers with motif R 2 (2)(8). These dimers are further connected by N-H⋯O hydrogen bonds, forming R 2 (2)(12) dimers. As a result, hydrogen-bonded chains running along [110] are formed. C-H⋯S inter-actions also occur. The terminal two C atoms of the butyl chain are disordered over two positions with an occupancy ratio of 0.54:0.46.

4.
Radiol Case Rep ; 6(4): 565, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-27307939

RESUMEN

Lower trapezius muscle injuries have not been previously described in the literature. We present a case of avulsion of the trapezius muscle from the T3-T9 spinous processes with subsequent hematoma formation, seen on magnetic resonance imaging.

5.
Fitoterapia ; 76(3-4): 310-5, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15885927

RESUMEN

Petroleum ether and benzene extracts of Clemeo felina, given orally at doses of 300 mg kg(-1) day(-1) for 30 days, were found to be antidiabetic and antihyperlipemic on alloxan diabetic rats. Moreover, a significant decrease in the activities of serum enzymes like alkaline phosphatase, acid phosphatase and HMGCoA reductase activity in the liver was observed. However, treatment of rats with the extracts as well as standard antidiabetic drugs increased liver hexakinase activity and serum LDH activity.


Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Hipoglucemiantes/farmacología , Hipolipemiantes/farmacología , Extractos Vegetales/farmacología , Animales , Gliburida/farmacología , Hipoglucemiantes/química , Hipolipemiantes/química , Insulina/farmacología , Masculino , Ratas , Ratas Wistar
6.
Spectrochim Acta A Mol Biomol Spectrosc ; 60(8-9): 1839-43, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15248958

RESUMEN

The fluorescence quenching of 4-aminodiphenyl (4ADP) with chloromethanes (CH2Cl2, CHCl3 and CCl4) have been studied in solvents of different polarity and viscosity. The quenching rate constants (kq) have been determined in all solvents. For CCl4 and CHCl3 quenching, the kq depends on solvent viscosity whereas for CH2Cl2, the kq values show a mixed trend with no clear-cut variation with either solvent polarity or solvent viscosity. Quenching mechanism involving an intermediate donor-acceptor complex formation is proposed for CH2Cl2 quenching. A positive deviation was observed in the Stern-Volmer (SV) plot for CCl4 quenching in hexane. The static-dynamic model could explain this.


Asunto(s)
Compuestos de Aminobifenilo/química , Tetracloruro de Carbono , Cloroformo , Colorantes Fluorescentes/química , Hexanos , Cloruro de Metileno , Soluciones , Espectrometría de Fluorescencia , Espectrofotometría
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