- 1H Spin-Lattice Relaxation in a NH4HSO4 Single Crystal
-
The proton NMR line width and spin-lattice relaxation times for the NH 4HSO4 single crystal were studied over a wide temperature range. The proton spin-lattice relaxation time for NH4HSO 4 has a minimum value, which is attributed to the effect of molecular motion. The 1H spin-lattice relaxation times occurring in phases I and III are attributed to the same motions of NH4 ions. The activation energies for the reorientation motions in phases I and III are 0.98 and 4.61 kcal/mol, respectively. In phase II, the activation energy is 5.92 kcal/mol. The large change in the activation energy between phases I and II indicates that the NH4 groups are affected during this transition; however, the motion of the NH4+ ions between phases II and III does not play an important role in the phase change.
- Lim, Ae Ran,Han, Tae Jong,Jung, Jae Kap,Park, Hyun Min
-
-
Read Online
- SIMULTANEOUS REMOVAL OF NOx AND SOx FROM FLUE GAS BY USE OF MOLTEN HYDROGENSULFATES AS REACTION MEDIA
-
The simultaneous removal of NOx and SOx by reaction with ammonia from flue gas was found to be attained at temperature ranging from 150 to 200 deg C in molten salts of hydrogensulfates dissolving V2O5.The addition of transition metal sulfates such as Ti(SO4)2, Zr(SO4)2 or CuSO4 led to a marked increase in the SOx removal.
- Shikada, Tsutomu,Oba, Takamasa,Fujimoto, Kaoru,Tominaga, Hiro-o
-
-
Read Online
- On the high-temperature phase transitions of NH4HSO4
-
Modulated differential scanning calorimetry (MDSC), thermogravimetric analysis (TGA) and X-ray diffraction (XRD) were used to study the phase behaviour of NH4HSO4 (AHS) above room temperature. For powder AHS measured during successive thermal cycles, the MDSC curves show an endothermic peak at 147°C on heating scans and an exothermic peak at about 115°C on subsequent cooling runs. However, after the second thermal cycle, a second endothermic peak starts to appear at about 135°C on heating runs whose intensity increases on subsequent cycles. The thermogravimetric measurements on powder AHS show weight loss above 135°C. X-ray powder diffraction data for AHS heated to 140°C during 24 hours, show the diffraction pattern for (NH4)2S2O7. We discuss the endothermic effect at 135°C in terms of a partial dehydration setting in at reaction sites distributed on the surface of the crystals.
- Diosa,Fernandez,Vargas,Torijano,Mellander
-
-
Read Online
- Raman and X-ray investigations of ferroelectric phase transition in NH 4HSO4
-
Temperature-dependent Raman spectroscopy and X-ray diffraction studies have been carried out on NH4HSO4 single crystals in the temperature range 77-298 K. Two structural transitions driven by the molecular ordering and change in crys
- Swain, Diptikanta,Bhadram, Venkata Srinu,Chowdhury, Papia,Narayana, Chandrabhas
-
-
Read Online
- Physicochemical properties of a microelement fertilizer with amino acids
-
The physicochemical properties of the initial components and products were studied with the aim of production of a microelement fertilizer with an amino acid concentrate. The physicochemical properties of the amino acid concentrate and its influence on the stability and sorption properties of fertilizers enriched in microelements were studied.
- Paleckiene,Sviklas,Slinksiene
-
p. 352 - 357
(2008/02/03)
-
- Manufacture and use of an deposition aid
-
A homogenous composition which contains at least one pesticide and at least one deposition or drift agent.
- -
-
-
- Process for the preparation of 3-(methylthio)propanal
-
A process for the continuous preparation of 3-(methylthio)propanal. A liquid reaction medium is contacted with a gaseous acrolein feed stream in a gas/liquid contact zone. The reaction medium contains 3-(methylthio)propanal, methyl mercaptan and a catalyst for the reaction between methyl mercaptan and acrolein. The gaseous acrolein feed stream comprises acrolein vapor and non-condensable gas. Acrolein is transferred from the acrolein feed stream to the reaction medium and reacts with methyl mercaptan in that medium to produce a liquid reaction product containing 3-(methylthio)propanal. The non-condensable gas is separated from the liquid reaction product. The reaction product is divided into a product fraction and a circulating fraction, and the circulating fraction is recycled to the gas/liquid contact zone.
- -
-
-
- Method for making 4,4'-dihydroxydiphenyl ether
-
A method for making 4,4'-dihydroxydiphenyl ether from diphenyl ether by oxidatively iodinating diphenyl ether to 4,4'-diiododiphenyl ether and/or 4-hydroxy-4'-iododiphenyl ether, hydrolyzing this product with a base, recovering iodine from the solution containing iodide, and recycling the iodine to the iodination step.
- -
-
-
- Kinetics of the Reaction between Hydroxylamine and Sodium Bisulfite
-
Hidroxylamine and sulfur dioxide react in aqueous solution to form either sulfamic acid or ammonium bisulfate.Rate studies have been performed as a function of temperature.The rate law has been determined.The enthalpy and entropy of activation for the formation of both sulfamic acid and ammonium bisulfate have been evaluated.
- Gomiscek, S.,Clem. R.,Novakov, T.,Chang, S. G.
-
p. 2567 - 2569
(2007/10/02)
-
- Process for the recovery of ε-caprolactam from a distillation residue containing ε-caprolactam
-
A method of recovering ε-caprolactam from the residue remaining from the distillation of impure ε-caprolactam wherein the residue is treated with sulphuric acid or oleum at a temperature between about 80° C. and about 140° C. and the resultant mixture neutralized. The lactam is then extracted with an organic solvent with the lactam then recovered from the resultant solution.
- -
-
-
