Authors:Daniya Rakhmatullina, Alexander Alyabyev, Tatiana Ogorodnikova, and Anastasia Ponomareva
In the past decade, the nitricoxide (NO) effect on plants metabolism has been given much consideration [ 1 , 2 ]. NO is a short-lived free radical that diffuses through membranes. NO is found in different plant
Authors:D. Axente, O. Piringer, M. Abrudean, A. Bâldea, and N. Palibroda
The rate of the15N/14N isotopic exchange between NO−HNO3 at high nitric acid concentration (2–10M) have been measured. The experimental data were obtained by contacting nitric oxide
at atmospheric pressure with nitric acid solution labelled with15N, in a glass contactor.
The rate of nitrogen isotope exchange between NO and HNO3 has been measured as a function of nitric oxide pressure 0.1–0.4 MPa for 1 and 2 M·1–1 HNO3. It is concluded that15N/14N exchange rate in NO–HNO3 system has a linear dependence of NO pressure as indicated by rate measurements at different NO partial pressure and constant overall pressure, by adding helium in reactor. Using the rate law:R=k[HNO3]2[N2O3] the15N/14N exchange rates for nitric acid concentrations 1.5–10 M·1–1 were calculated.
The rate of nitrogen isotope exchange between NO and HNO3 has been measured as a function of nitric acid concentration of 1.5–4M·1–1. The exchange rate law is shown to beR=k[HNO3]2[N2O3] and the measured activation energy isE=67.78kJ ·M–1 (16.2 kcal·M–1). It is concluded that N2O3 participates in15N/14N exchange between NO and HNO3 at nitric acid concentrations higher than 1.5M·1–1.
Preparation of a Fe-mordenite catalysts was carried out by impregnation using Fe(acac)3 precursor in order to have iron oxide species deposited at the surface of the zeolite. The selective presence of iron oxide species was determined and ascertained by temperature programmed reduction (TPR). In the selective catalytic reduction of NO by ammonia, no difference of conversion between the catalysts was observed indicating that well dispersed iron oxide species are active species for this reaction. Nevertheless, the obtained activity remains lower than catalysts containing iron cationic species at the exchange sites.
Authors:András Németh, Krisztián Stadler, Judit Jakus, and Tamás Vidóczy
between nitric dioxide ( • NO 2 ), carbonate radical anion (CO 3 •− ) and hydroxyl radical ( • OH) in the production of luminol radicals, (iv) the contribution of peroxynitrous acid (ONOOH) homolysis, and (v) that of nitricoxide ( • NO) oxidation to the
Authors:L. Chmielarz, M. Zbroja, P. Kuśtrowski, B. Dudek, A. Rafalska-Łasocha, and R. Dziembaj
Alumina, zirconia and titania pillared montmorillonites additionally modified with silver were tested as catalysts of NO reduction
with NH3 or C2H4. Ammonia was much more effective reducer of NO than ethylene. The silver containing TiO2-pillared clay has been found to be the most active catalyst for NO reduction both with NH3 or C2H4. Oxidation of the reducing agents by oxygen limited the NO conversion in the high temperature region. The ammonia and nitric
oxide adsorption sites were studied by the temperature programmed desorption methods (TPD).
Authors:Noufissa Zanati, Michael Mathews, Indika Perera, John Moran, Jean Boutros, Alan Riga, and Mekki Bayachou
The long-term goal of this investigation is to study the effects of increased cholesterol levels on the molecular activity
of membrane-bound enzymes such as nitric oxide synthase, that are critical in the functioning of the cardiovascular system.
In this particular investigation, we used differential scanning calorimetry (DSC) and dielectric thermal analysis (DETA) to
study the effect of added cholesterol on melting/recrystallization and dielectric behavior, respectively, of phosphatidylcholine
(PC) bilayered thin films. We also used electrochemical methods to investigate the effect of added cholesterol on the redox
behavior of the oxygenase domain of nitric oxide synthase as a probe embedded in the PC films. The results show that added
cholesterol in the PC films seems to depress the molecular dynamics as indicated by lowered current responses in the presence
of cholesterol as well as a slight increase of the transition temperature in the overall two-phase regime behavior observed
in PC–cholesterol films. These results are rationalized in the context of the general DSC and DETA behaviors of the PC–chol
Authors:Kwang-Wook Kim, Eil-Hee Lee, In-Kyu Choi, Jae-Hyung Yoo, and Hyun-Soo Park
The electrochemical redox behavior of nitric acid was studied using a glassy carbon fiber column electrode system, and its reaction mechanism was suggested and confirmed in several ways. Electrochemical reactions in less than 2.0M nitric acid was not observed. However, in more than 2.0M nitric acid, the reduction of nitric acid to nitrous acid occurred and the reduction rate was slow so that the nitric acid solution had to be in contact with an electrode for a period of time long enough for an apparent reduction current of nitric acid to nitrous acid to be observed. The nitrous acid generated in more than 2.0M nitric acid was rapidly and easily reduced to nitric oxide by an autocatalytic reaction. Sulfamic acid was confirmed to be effective to destroy the nitrous acid. At least 0.05M sulfamic acid was necessary to scavenge the nitrous acid generated in 3.5M nitric acid.
Authors:I. Pitkänen, J. Huttunen, H. Halttunen, and R. Vesterinen
FTIR spectrometry combined with TG provides information regarding mass changes in a sample and permits qualitative identification
of the gases evolved during thermal degradation. Various fuels were studied: coal, peat, wood chips, bark, reed canary grass
and municipal solid waste. The gases evolved in a TG analyser were transferred to the FTIR via a heated teflon line. The spectra
and thermoanalytical curves indicated that the major gases evolved were carbon dioxide and water, while there were many minor
gases, e.g. carbon monoxide, methane, ethane, methanol, ethanol, formic acid, acetic acid and formaldehyde. Separate evolved
gas spectra also revealed the release of ammonia from biomasses and peat. Sulphur dioxide and nitric oxide were found in some
cases. The evolution of the minor gases and water parallelled the first step in the TG curve. Solid fuels dried at 100C mainly
lost water and a little ammonia.