An EISCAT UHF/ESR Experiment That Explains How Ionospheric Irregularities Induce GPS Phase Fluctuations at Auroral and Polar Latitudes

A limitation to the use of Global Navigation Satellite System (GNSS) for precise and real-time services is introduced by irregularities in the ionospheric plasma density. An EISCAT UHF/ESR experiment was conducted to characterize the effect of electron density irregularities on temporal fluctuations in TEC along directions transverse to GPS ray paths in the high latitudes ionosphere. Two representative case studies are described: Enhancements in temporal TEC fluctuations originating (a) in the auroral ionosphere following auroral particle precipitation and (b) in the polar ionosphere following the drift of a polar patch as well as particle precipitation. The results indicate that the origin of enhancements in TEC fluctuations is due to the propagation through large-to-medium scale irregularities (i.e., ranging from few kilometres in the E region to few tens of kilometres in the F region) and occurring over spatial distances of up to approximately 400 km in the E region and up to approximately 800 km in the F region with a patchy distribution. Furthermore, the results indicate that enhancements in TEC fluctuations produced by polar plasma patches and particle precipitation occur over similar temporal scales, thus explaining the overall observation of higher phase scintillation indices in the high-latitude ionosphere. The similarity in the temporal scales over which enhancements in TEC fluctuations occur in the presence of both particle precipitation and plasma patches suggests an intrinsic limitation in the monitoring and tracking of plasma patches through ground GNSS observations

Antimalarial Potential of Carica papaya

The study determined if administration of Vernonia amygdalina and Carica papaya plants provides synergistic effects in ameliorating plasmodium infection in mice. Thirty mice (17.88–25.3 g) were divided into 6 groups of 5 mice each. Group 1 was normal control, while groups 2–6 were intraperitoneally inoculated 2.5 × 107 Plasmodium berghei parasitized red blood cell, followed by daily administration of 350 mg/kg aqueous leaf extracts after establishment of infection. Group 2 was disease control, while group 6 was treated with standard drug for four consecutive days. The results showed significant (P<0.05) reduction in percentage of parasite load between the infected treatment groups and disease control group at day 3 after infection, which remained consistent until the end of the experiment. All infected treated groups showed significant (P<0.05) increases in RBC and PCV recovery compared to the disease control, with the exception of WBC. There was insignificant (P>0.05) change in mean body weight of all treated groups except in disease control group. Histological studies of the infected mice indicate recovery of hepatic cells from congested black pigmentation. The reduction in parasite load and recovery of hepatic cell damage/hematological parameters were induced by these plant extracts. This highlighted the important usage of the plant in traditional remedy of malaria infection

Isolation, characterization and antibacterial evaluation of Zymosterol from the Root of Pachystela Brevipes (Sapotaceae)

Abstract: The root of Pachystelabrevipes, which has some medicinal applications was investigated. The results of the phytochemical analysis showed the presence of carbohydrates, cardiac glycosides, saponins, steroids/ triterpenes, flavonoids, tannins and alkaloids. The crude extracts showed zone of inhibition in the range, 16-19 mm (pet.ether), 20-24 mm (chloroform), 20-27 mm (ethylacetate) and 20-22 mm (methanol), against the test organism; Nettricillin resistant staphylococcus aureus, Staphylococcus aureus, Escherichia coli; Salmonella typhi, Shigelladysenterea, Pseudomonas aeruginosa, klebsiella pneumonia, Candida stellatoidea, Candida tropicalis, Candida krusei, Proteus mirabilis, Proteus vulgaris and Streptococcus feacalis. The minimum inhibitory concentration (MIC) of 2.5 mg/mL was recorded for the chloroform, ethylacetate and methanol fraction against the entire test organism except S. pyogenes, C. krusei, P. mirabilis and P. vulgaris. The petroleum ether fraction showed MIC of 5.0 mg/mL. The minimum bactericidal/fungicidal concentration (MBC/MFC) determination showed that a concentration of 5-10 mg/mL of the pet.ether, chlororform, ethylacetate and methanol fraction could completely kill all the test organism except S. pyogenes, C. krusei, P. mirabilis and P. vulgaris.Zymosterol (3β-hydroxy-4β-methyl-5α-cholesta-6,22-diene-4α-carboxylic acid) was isolated from the ethyl acetate fraction (EAF) and confirmed purely by spectral techniques

Synthesis and evaluation of the pharmacological activity of open analogues of cromakalim carrying urea and thiourea moieties

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Synthesis and characterization of Zn(1-x)NixAl2O4 spinels as a new heterogeneous catalyst of Biginelli's reaction

Zn(1-x)NixAl2O4 (x = 0.0-1.0) spinels were prepared at 800°C by co-precipitation method and characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The specific surface area was determined by BET. SEM image showed nano sized spherical particles. XPS confirmed the valence states of the metals, showing moderate Lewis character for the surface of materials. The powders were successfully used as new heterogeneous catalysts of Biginelli's reaction, a one-pot threecomponent reaction, leading to some dihydropyrimidinones (DHPMs). These new catalysts that produced good yields of DHPMs, were easily recovered by simple filtration and subsequently reused with persistent activity, and they are non-toxic and environmentally friendly. The optimum amount of catalyst is 20% by weight of benzaldehyde derivatives, while the doping amount has been found optimal for x = 0.1

Crystal structure, mechanical, electronic, optical and thermoelectric characteristics of Cs2MCl6 (M = Se, Sn, Te and Ti) cubic double perovskites

The crystal structure, mechanical, electronic, optical and thermoelectric characteristics of Cs2MCl6 (M = Se, Sn, Te and Ti) cubic double perovskites are studied within GGA, GGA-mBJ and EV-GGA functionals. The M − Cl bond lengths are shorter and especially in Cs2TiCl6 double perovskite, which reflects the strong interaction between M and Cl atoms and this is correlated with its better chemical stability. The negativity of formation energy and Helmholtz free energy and no imaginary phonon modes throughout the Brillouin zone confirm the thermal, thermodynamic and dynamical stability of these double perovskites. Semiconductors Cs2MCl6 (M = Se, Sn, Te and Ti) double perovskites with flat conduction and valence bands, and an indirect band gap are p-type carriers. A high Seebeck coefficient, adequate ZT values ​​and non-toxicity make these compounds attractive for thermoelectric applications at high temperature and spintronic technology. The empty first conduction band corresponds to their band gap, and the transition occurs from Cl-p to (Se-p, Sn-p, Te-p and Ti-d). The high static dielectric constant and the intense peak of the real part in the ultraviolet energy range favor less the recombination rate of charge carriers and their use in optoelectronic devices. The indirect band gap, high absorption in ultraviolet energy, high static refractive index make these cubic double perovskites as ideal materials for solar cell applications

Effect of temperature and glass content on crystalline phases in porcelain sintered with recovered automotive glass

In the pursuit of sustainable porcelain production, this research examines the potential of using recovered automotive glass as a substitute for traditional feldspar, specifically feldspar imported from Spain. Porcelain samples were sintered at different temperatures and with varied proportions of automotive glass. The crystalline phases formed post-sintering were determined through X-ray diffraction and quantified by dissolving the porcelain in concentrated hydrofluoric acid. Results revealed that the inclusion of automotive glass, owing to its dissolved oxide content, accelerated the porcelain melting process and led to an increase in the vitreous phase. Notably, anorthite phases became dominant and mullite formation was evident at 1100 °C, stabilizing in samples G00 and G10, and then increasing at 1200 °C due to the emergence of secondary mullite. This secondary mullite forms from the residual silica after the primary mullite formation and the aluminium in the feldspars, which is about 17 %. For samples G20 and G30, only primary mullite was observed due to the decreased aluminium content resultant from feldspar replacement by glass. These findings underscore the viability of automotive glass in porcelain production, providing a sustainable and effective alternative to feldspar