Absolute photodissociation cross sections of gas phase sodium chloride at room temperature

1986 ◽  
Vol 84 (8) ◽  
pp. 4378-4384 ◽  
Author(s):  
J. A. Silver ◽  
D. R. Worsnop ◽  
A. Freedman ◽  
C. E. Kolb
Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 431
Author(s):  
Giorgio Turri ◽  
Scott Webster ◽  
Michael Bass ◽  
Alessandra Toncelli

Spectroscopic properties of neodymium-doped yttrium lithium fluoride were measured at different temperatures from 35 K to 350 K in specimens with 1 at% Nd3+ concentration. The absorption spectrum was measured at room temperature from 400 to 900 nm. The decay dynamics of the 4F3/2 multiplet was investigated by measuring the fluorescence lifetime as a function of the sample temperature, and the radiative decay time was derived by extrapolation to 0 K. The stimulated-emission cross-sections of the transitions from the 4F3/2 to the 4I9/2, 4I11/2, and 4I13/2 levels were obtained from the fluorescence spectrum measured at different temperatures, using the Aull–Jenssen technique. The results show consistency with most results previously published at room temperature, extending them over a broader range of temperatures. A semi-empirical formula for the magnitude of the stimulated-emission cross-section as a function of temperature in the 250 K to 350 K temperature range, is presented for the most intense transitions to the 4I11/2 and 4I13/2 levels.


1979 ◽  
Vol 34 (11) ◽  
pp. 1269-1274 ◽  
Author(s):  
Erik Bjarnov

Vinyl ketene (1,3-butadiene-1-one) has been synthesized by vacuum pyrolysis of 3-butenoic 2-butenoic anhydride. The microwave and infrared spectra of vinyl ketene in the gas phase at room temperature have been studied. The trans-rotamer has been identified, and the spectroscopic constants were found to be Ã= 39571(48) MHz, B̃ = 2392.9252(28) MHz, C̃ = 2256.0089(28) MHz, ⊿j = 0.414(31) kHz, and ⊿JK = - 34.694(92) kHz. The electrical dipole moment was found to be 0.987(23) D with μa = 0.865(14) D and μb = 0.475(41) D. A tentative assignment has been made for 17 of the 21 normal modes of vibration


2014 ◽  
Vol 69 (11-12) ◽  
pp. 1229-1236
Author(s):  
Matthias Wörsching ◽  
Constantin Hoch

Abstract Cesium hydroxide, CsOH, was for the first time characterised on the basis of single-crystal data. The structure is isotypic to the one of the room-temperature modification of NaOH and can be derived from the NaCl structure type thus allowing the comparison of all alkali metal hydroxide structures. Raman spectroscopic investigations show the hydroxide anion to behave almost as a free ion as in the gas phase. The X-ray investigations indicate possible H atom positions.


1981 ◽  
Vol 59 (11) ◽  
pp. 1615-1621 ◽  
Author(s):  
Scott D. Tanner ◽  
Gervase I. Mackay ◽  
Diethard K. Bohme

Flowing afterglow measurements are reported which provide rate constants and product identifications at 298 ± 2 K for the gas-phase reactions of OH− with CH3OH, C2H5OH, CH3OCH3, CH2O, CH3CHO, CH3COCH3, CH2CO, HCOOH, HCOOCH3, CH2=C=CH2, CH3—C≡CH, and C6H5CH3. The main channels observed were proton transfer and solvation of the OH−. Hydration with one molecule of H2O was observed either to reduce the rate slightly and lead to products which are the hydrated analogues of the "nude" reaction, or to stop the reaction completely, k ≤ 10−12 cm3 molecule−1 s−1. The reaction of OH−•H2O with CH3—C≡CH showed an uncertain intermediate behaviour.


Author(s):  
Rabih Mansour ◽  
Yogesh P. Singh ◽  
Manigandan Kannan ◽  
Gregory N. Morscher ◽  
Frank Abdi ◽  
...  

Interlaminar fracture properties play an important role in predicting failure of structural components for CMC materials. In engine applications, components are subject to large thermal gradients which induce interlaminar stresses. One of the main challenges in evaluating interlaminar fracture toughness at room and elevated temperatures is the development of an experimental setup that provides ease for testing and allows for in-situ monitoring of the interlaminar crack growth. Therefore, a wedge-loaded DCB testing method is developed. The method utilize electrical resistance to monitor crack growth and was applied to a woven polymer infiltrated pyrolysis (PIP) SiC/SiNC composite. Post-testing inspection was carried out using optical microscopy of polished cross-sections, showing crack morphology. It was found that crack growth rate at room temperature is double the one at 815 °C for initial tests in this composite system. Estimates of Mode I energy release rate suggests flat R-curve behavior at room temperature in comparison to rising R-curve behavior at 815 °C.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
T. Nowozin ◽  
D. Bimberg ◽  
K. Daqrouq ◽  
M. N. Ajour ◽  
M. Awedh

The present paper investigates the current status of the storage times in self-organized QDs, surveying a variety of heterostructures advantageous for strong electron and/or hole confinement. Experimental data for the electronic properties, such as localization energies and capture cross-sections, are listed. Based on the theory of thermal emission of carriers from QDs, we extrapolate the values for materials that would increase the storage time at room temperature to more than millions of years. For electron storage, GaSb/AlSb, GaN/AlN, and InAs/AlSb are proposed. For hole storage, GaSb/Al0.9Ga0.1As, GaSb/GaP, and GaSb/AlP are promising candidates.


2008 ◽  
Vol 187 (3) ◽  
pp. 289-297 ◽  
Author(s):  
Janne Raula ◽  
Annukka Kuivanen ◽  
Anna Lähde ◽  
Esko I. Kauppinen

1973 ◽  
Vol 51 (21) ◽  
pp. 3605-3619 ◽  
Author(s):  
C. Willis ◽  
R. A. Back

Preparation of di-imide by passing hydrazine vapor through a microwave discharge yields mixtures with NH3 containing typically about 15% N2H2, estimated from the gases evolved on decomposition. The behavior of the mixture (which melts at −65 °C) on warming from −196 to −30 °C suggests a strong interaction between the components. Measurements of magnetic susceptibility and e.p.r. experiments showed that N2H2 is not strongly paramagnetic, which with other observations points to a singlet rather than a triplet ground-state.Di-imide can be vaporized efficiently, together with NH3, by rapid warming, and the vapor is surprisingly long-lived, with a typical half-life of several minutes at room temperature. The near-u.v. (3200–4400 Å) absorption spectrum of the vapor was photographed; it shows well-defined but diffuse bands, with εmax = 6(± 3) at 3450 Å.Di-imide decomposes at room temperature in two ways:[Formula: see text][Formula: see text]Formation of NH3 was not observed but cannot be ruled out. The decomposition of the vapor is complicated by a sizeable and variable decomposition that occurs rapidly during the vaporization. The stoichiometry of this and the vapor-phase decomposition depends on total pressure and di-imide concentration. The kinetics of the decomposition of the vapor were studied from 22 to 200 °C by following the disappearance of N2H2 by absorption of light at 3450 Å, or the formation of N2H4 by absorption at 2400 Å, and by mass spectrometry. The kinetics are complex and can be either first- or second-order, or mixed, depending on surface conditions. The effect of olefin additives on the decomposition was studied, and is also complex.Mechanisms for the decomposition are discussed, including the possible role of trans-cis isomerization. The relatively long lifetime found for di-imide in the gas phase suggests that it may be an important intermediate in many reactions of hydronitrogen systems.


Author(s):  
Popi Patilaya ◽  
Dadang Irfan Husori ◽  
Imam Bagus Sumantri

ABSTRACTObjective: This study was to investigate the anthelmintic effects of ethanol extract of Curanga fel-terrae leaves on Ascaridia galli.Methods: Extract of C. fel-terrae was prepared by percolating the dried powder of the plant leaves. To observe anthelmintic effects, A. galli wasexposed to the plant extract solutions in different concentrations at room temperature for 72 hrs. Sodium chloride 0.9%, sodium carboxymethylcellulose 0.5%, and albendazole 0.1% were served as negative control, solvent control, and positive control, respectively. The anthelmintic effectswere determined by observing the time taken for paralysis and the time taken for death of A. galli during experiment.Results: The results demonstrated that there were no different effects between negative and solvent controls. However, the ethanol extract ofC. fel-terrae leaves exhibited significantly paralysis and death effects toward A. galli. The plant extracts at the concentration of 100 mg/ml showedsimilar anthelmintic effects with albendazole 0.1%. This study also indicated that the paralysis and death effects of plant extract were shorter whenthe worms exposed with the concentration above of 100 mg/ml.Conclusion: This study indicated that the ethanol extract of C. fel-terrae leaves has potential anthelmintic effects on A. galli.Keywords: Curanga fel-terrae, Ascaridia galli, Anthelmintic, Helminthiasis, Ascariasis. 


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