Structural and spectroscopic studies of a nanostructured silicon–perovskite interface

Nanoscale ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 4498-4505 ◽  
Author(s):  
Roberto Gonzalez-Rodriguez ◽  
Viviana C. P. Costa ◽  
Géraud Delport ◽  
Kyle Frohna ◽  
Robert L. Z. Hoye ◽  
...  
Keyword(s):  
Spectroscopic Properties ◽  
Spectroscopic Studies ◽  
Silicon Nanotubes ◽  
Nanostructured Silicon ◽  
Inner Diameter

This work investigates the formation of APbBr3 structures (A = CH3NH3+ (MA), Cs+) in silicon and oxidized silicon nanotubes (SiNTs) with varying inner diameter, as well as the role of the interface in perovskite spectroscopic properties.

Structural, magnetic and Mössbauer spectroscopic studies of the [Fe(3-bpp)2](CF3COO)2 complex: role of crystal packing leading to an incomplete Fe(ii) high spin ⇋ low spin transition

CrystEngComm ◽  
2021 ◽  
Vol 23 (15) ◽  
pp. 2854-2861
Author(s):  
Kristian Handoyo Sugiyarto ◽  
Djulia Onggo ◽  
Hiroki Akutsu ◽  
Varimalla Raghavendra Reddy ◽  
Hari Sutrisno ◽  
...  
Keyword(s):  
High Spin ◽  
Crystal Packing ◽  
Spin Transition ◽  
Spectroscopic Studies ◽  
Mononuclear Complex

Mononuclear complex [Fe(3-bpp)2](CF3COO)2 exhibits a thermal (HS + HS) ⇋ (HS + LS) transition at ∼226 K which is not associated with any crystallographic transition.

scholarly journals Experimental and Theoretical Studies of Sonically Prepared Cu–Y, Cu–USY and Cu–ZSM-5 Catalysts for SCR deNOx

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 824
Author(s):  
Przemysław J. Jodłowski ◽  
Izabela Czekaj ◽  
Patrycja Stachurska ◽  
Łukasz Kuterasiński ◽  
Lucjan Chmielarz ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Ultrasonic Irradiation ◽  
Active Phase ◽  
Spectroscopic Studies ◽  
In Situ Drifts ◽  
Ft Ir ◽  
Diffuse Reflectance Infrared ◽  
Experimental And Theoretical Studies

The objective of our study was to prepare Y-, USY- and ZSM-5-based catalysts by hydrothermal synthesis, followed by copper active-phase deposition by either conventional ion-exchange or ultrasonic irradiation. The resulting materials were characterized by XRD, BET, SEM, TEM, Raman, UV-Vis, monitoring ammonia and nitrogen oxide sorption by FT-IR and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). XRD data confirmed the purity and structure of the Y/USY or ZSM-5 zeolites. The nitrogen and ammonia sorption results indicated that the materials were highly porous and acidic. The metallic active phase was found in the form of cations in ion-exchanged zeolites and in the form of nanoparticle metal oxides in sonochemically prepared catalysts. The latter showed full activity and high stability in the SCR deNOx reaction. The faujasite-based catalysts were fully active at 200–400 °C, whereas the ZSM-5-based catalysts reached 100% activity at 400–500 °C. Our in situ DRIFTS experiments revealed that Cu–O(NO) and Cu–NH3 were intermediates, also indicating the role of Brønsted sites in the formation of NH4NO3. Furthermore, the results from our experimental in situ spectroscopic studies were compared with DFT models. Overall, our findings suggest two possible mechanisms for the deNOx reaction, depending on the method of catalyst preparation (i.e., conventional ion-exchange vs. ultrasonic irradiation).

Assessment of role of iron ions on the physical and spectroscopic properties of multi-component Na2O−PbO−Bi2O3−SiO2 glass ceramics

2017 ◽  
Vol 91 (1) ◽  
pp. 92-107 ◽  
Author(s):  
M. V. Sambasiva Rao ◽  
A. Suneel Kumar ◽  
G. Chinna Ram ◽  
Ch. Tirupataiah ◽  
D. Krishna Rao
Keyword(s):  
Glass Ceramics ◽  
Spectroscopic Properties ◽  
Iron Ions ◽  
Sio2 Glass

Optical Spectroscopic Studies of a Soluble Fluorene-Based Conjugated Polymer: A Hydrostatic Pressure and Temperature Study

2001 ◽  
Vol 708 ◽  
Author(s):  
S. Guha ◽  
J.D. Rice ◽  
C. M. Martin ◽  
W. Graupner ◽  
M. Chandrasekhar ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Conjugated Polymer ◽  
Spectroscopic Properties ◽  
Spectroscopic Studies ◽  
Phonon Interaction ◽  
Optical Studies ◽  
Strong Electron ◽  
Conjugated Molecules ◽  
Electron Phonon Interaction ◽  
Backbone Conformation

ABSTRACTSpectroscopic properties of conjugated molecules/polymers have varying degrees of sensitivity to backbone conformation. Optical studies are presented as a function of temperature and hydrostatic pressure, using photoluminescence and Raman scattering from two polymers with distinct differences in their backbone conformation, namely, polyfluorene (PF) and ladder type poly(para-phenylene)(m-LPPP). In contrast to the photoluminescence (PL) vibronics in mLPPP, the 0-0 PL vibronic peak in PF shows a red-shift with increasing temperatures. Pressure studies reveal that the PL spectrum of PF red-shifts and broadens with increasing pressures. The phonon lines in PF show an antiresonance effect at higher pressures indicating a strong electron-phonon interaction.

The antifungal factors in barley. IV. Isolation, structure, and synthesis of the hordatines

1967 ◽  
Vol 45 (15) ◽  
pp. 1745-1760 ◽  
Author(s):  
A. Stoessl
Keyword(s):  
Oxidative Coupling ◽  
Degradation Products ◽  
Spectroscopic Studies

Careful fractionation of extracts prepared from barley coleoptiles gave small amounts of pure hordatines A and B and substantial amounts of a mixture of their glucosides. The structures of the hordatines were deduced by degradative and spectroscopic studies and by the synthesis of some degradation products. A synthesis of racemic hordatine A analogous to its probable biogenesis was achieved by the oxidative coupling of coumaroylagmatine.The possible role of the hordatines in lignification is briefly discussed.

New insights into the protogenic and spectroscopic properties of commercial tannic acid: the role of gallic acid impurities

2018 ◽  
Vol 42 (10) ◽  
pp. 7703-7712 ◽  
Author(s):  
G. Ghigo ◽  
S. Berto ◽  
M. Minella ◽  
D. Vione ◽  
E. Alladio ◽  
...  
Keyword(s):  
Gallic Acid ◽  
Tannic Acid ◽  
Spectroscopic Properties ◽  
Spectral Features

Assessment of a protonation model for tannic acid and characterization of the spectral features of its protonated and dissociated species.

Role of valence state of vanadium ions on structural and spectroscopic properties of sodium lead bismuth silicate glass ceramics

2018 ◽  
Author(s):  
M. V. Sambasiva Rao ◽  
Ch. Tirupataiah ◽  
A. Suneel Kumar ◽  
T. Narendrudu ◽  
S. Suresh ◽  
...  
Keyword(s):  
Silicate Glass ◽  
Valence State ◽  
Glass Ceramics ◽  
Spectroscopic Properties ◽  
Bismuth Silicate ◽  
Vanadium Ions

Abstract 16720: Cytoglobin Regulates Cardiovascular Function and Vessel Tone by Controlling the Rate of Vascular Nitric Oxide Metabolism

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Xiaoping Liu ◽  
Mohamed A El-Mahdy ◽  
Raed S Ismail ◽  
Sean Little ◽  
Le T Thuy ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Vascular Wall ◽  
No Donor ◽  
Nitric Oxide Metabolism ◽  
No Consumption ◽  
Potent Vasodilator ◽  
Inner Diameter ◽  
The Difference ◽  
Synthase Inhibitor

Cytoglobin (Cygb) can effectively metabolize nitric oxide (NO), a potent vasodilator, in the presence of oxygen and reductants. Cygb in the vascular wall may affect cardiovascular functions by changing the rate of NO metabolism. In this study, we directly tested the vascular role of Cygb using Cygb knockout (Cygb-/-) mice. The mean blood pressure of Cygb-/- and C57BL/6 wild type (WT) mice was 65.3 ± 1.9 mmHg and 93.7 ± 1.5 mmHg, respectively (n=10). Using echocardiography, we observed that cardiac output (CO) was increased in Cygb-/- mice compared to WT with values of 29.8 ± 3.9 vs 17.7 ± 0.9 ml/min. The systemic vascular resistance (SVR) of Cygb-/- mice was decreased by ~60% vs that of WT mice (Fig. 1). Further, the inner diameter (id) of aorta of Cygb-/- mice was dilated compared to WT with values of 2.2 ± 0.1 mm vs 1.5 ± 0.05 mm (n=5), respectively. After treatment with the NO synthase inhibitor L-NAME, no difference in the aortic id remained between Cygb-/- (1.55 ± 0.03 mm) and WT (1.49 ± 0.02 mm) mice, indicating that the NO pathway is responsible for the difference in vascular inner diameters and tone. Myograph experiments show that the aortic vasodilation response of Cygb-/- mice is much more sensitive to acetylcholine (Ach) or the NO donor nitroprusside (SNP) (EC50 shifts from 13 nM and 2.9 nM (WT mice) to 0.33 nM and 0.16 nM (Cygb-/-) for Ach and SNP, respectively). Using NO electrodes to measure the rate of NO consumption by SMCs and quantitative imunoblotting to estimate Cygb content in RSMCs-AR and Cygb knockdown RSMCs, we observed that 90% of NO consumption by RSMCs-AR is caused by the intracellular Cygb. Our results indicate that Cygb deficiency in the vascular wall of Cygb-/- mice greatly reduces the rate of NO metabolism and increases vascular NO concentration, resulting in vasodilation, increase in vessel lumen diameter, and decrease in SVR. These results demonstrate that Cygb regulates cardiac function and vessel tone by controlling the rate of vascular NO metabolism.

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