Influence Of HCl Research Articles

溶融NaCl-KCl-Na2SO4塗布下におけるNi-Cr-Mo合金の高温腐食に及ぼす雰囲気中HClの影響

溶融NaCl-KCl-Na₂SO₄塗布下におけるNi-Cr-Mo合金の高温腐食に及ぼす雰囲気中HClの影響

Sequential extraction separation for determination of technetium-99 in radwastes by ICP-MS

An approach based on sequential extraction separation and the subsequent ICP-MS measurement was introduced to determine 99Tc in radioactive wastes. The radwastes were firstly alkaline-fused and the 99Tc was separated by a sequential solvent extraction prior to ICP-MS measurement. NaDDC was selected as a chelation reagent in the solvent extraction processes. The influence of HCl and matrix concentration on the recovery yield and the effectiveness of removing isobar and unwanted radionuclides, such as 137Cs, 54Mn, 60Co and 110mAg, were evaluated. The designed sequential extraction procedure was optimized by an extraction experiment. The proposed technique is proven to be a simple and practical alternative for 99Tc determination in low-level radioactive wastes; chemical separation of 99Tc can be simplified and preconcentration such as precipitation and/or ion exchange, before the solvent extraction, can be excluded.

Experiments on The Influence of HCl on SO2 Removal in Spray Dry Absorption

Experiments on The Influence of HCl on SO2 Removal in Spray Dry Absorption

Synthesis of 4-(1-Adamantyl)- and 4-(1-Adamantylmethyl)-substituted Halothiazoles

1-Adamantyl bromomethyl ketone and 1-adamantylmethyl chloromethyl ketone react with potassium thiocyanate in dimethylformamide to give the corresponding thiocyanatoketones which cyclize under the influence of HCl into 4-(1-adamantyl) and 4(-adamantylmethyl)chlorothiazole respectively. 4-(1-Adamantyl)-2-amino-5-bromothiazole and its N-derivative were synthesized by the reaction of 1-adamantyl dibromomethyl ketone with thioureas and N-substituted thiourea in acetonitrile.

Effects of desolvation on line emission intensities and analyte transport in inductively coupled plasma atomic emission spectrometry using ultrasonic nebulization

The influence of HCl, KCl, KBr, KI and Ca in a nitric acid matrix on the emission signals and transport rates in inductively coupled plasma atomic emission spectrometry using ultrasonic nebulization with desolvation is studied. In general, a depression in the analyte emission signals in the presence of nitric acid is observed compared to that in solutions containing matrix elements in a nitric acid solution. This difference arises from the reduced analyte transport efficiencies. The greatest depressions in the analyte transport efficiency (by a factor of about 7 compared to the analyte transport efficiency for Mn) are observed for AsIII and SeIV in a nitric acid solution. The presence of KBr, KI, KCl and Ca in a concentration as low as 0.001 M has a large enhancement effect on the emission signals for Cu, AsIII and SeIV. The exceptions are Sb species in the presence of KBr, where a 50% depression in the analyte transport efficiency and the emission signal is observed in comparison to a nitric acid solution. Calcium and potassium bromide are the most efficient at eliminating the different valence state responses for As and Se. The transport efficiency for Cu is comparable to that of Mn in the presence of KI and Ca; however, KI is less suitable because it causes large memory effects. The present study shows that during the nebulization of the analyte solutions the adsorption of the analytes on the walls of the desolvating tubes and the rejection of the analytes to the drain solutions may occur. The former process is dominant for copper, whereas during the nebulization of AsIII and SeIV in nitric acid, the amount of the analytes in the drain increases. The depressions in the sensitivity for copper can be improved by decreasing the heating temperature of the desolvator and increasing the carrier gas flow rate.

The influence of HCl on the oxidation of iron at elevated temperatures

A study has been made of the effects of 0.1 to 1.0% HCl on the oxidation of iron in argon - 20% O 2 at 600°C and 700°C. The overall weight-change kinetics included contributions from weight increases due to growth of oxide and chloride scale by solid-state diffusion and to deposition of oxide following vaporization of FeCl 2 and subsequent reaction with oxygen, and weight losses due to complete removal of FeCl 2 vapour to the environment. The weight gains in HCl-containing gases were less than that in the HCl-free gas at 600 °C, but greater than that in the HCI-free gas at 700 °C. The kinetics could be described by a modified Tedmon equation; it was found that much of the scale growth resulted from the chloride-to-oxide reaction following vaporization of FeCl 2 from local sites on the metal surface while the contributions from solid-state diffusion were relatively small.

Corrosion behaviour of four high temperature engineering materials exposed to landfill gas engine flue gas

Four engineering materials commonly used in high-temperature applications were exposed to landfill gas engine flue gas for 25 days at 411°C. The flue gas was composed mostly of nitrogen and oxygen, although some carbon monoxide and hydrocarbons were detected together with low concentrations of hydrogen chloride gas and sulphur oxides. Hydrogen fluoride was not analysed, but, due to the nature of the fuel, may have been present at low levels. The materials tested were a carbon steel, a low alloy steel, a 12%Cr stainless steel and an austenitic stainless steel. Thin, protective films were formed on the 12%Cr and austenitic stainless steels, however, the corrosion products formed on carbon and low-alloy steels consisted of several layers, the outermost of which were extremely friable and non-adherent, especially on cooling from the flue gas working temperature. The maximum corrosion rate obtained was 70 μm yr–1 for carbon steel, which may be acceptable for a number of flue gas applications. The exposed coupons were examined using conventional techniques such as X-ray diffraction (XRD), optical microscopy (OM) and scanning electron microscopy (SEM). The predominant scale formation mechanism controlling the corrosion appeared to be simple oxidation type reactions, however, the influence of HCl, as evidenced by the presence of akaganeite (β-FeO(OH)), was hypothesised. A model describing the corrosion mechanism is proposed in order to provide an improved life prediction capability for such flue gas environments.

Corrosion behaviour of four high temperature engineering materials exposed to landfill gas engine flue gas

Four engineering materials commonly used in high-temperature applications were exposed to landfill gas engine flue gas for 25 days at 411°C. The flue gas was composed mostly of nitrogen and oxygen, although some carbon monoxide and hydrocarbons were detected together with low concentrations of hydrogen chloride gas and sulphur oxides. Hydrogen fluoride was not analysed, but, due to the nature of the fuel, may have been present at low levels. The materials tested were a carbon steel, a low alloy steel, a 12%Cr stainless steel and an austenitic stainless steel. Thin, protective films were formed on the 12%Cr and austenitic stainless steels, however, the corrosion products formed on carbon and low-alloy steels consisted of several layers, the outermost of which were extremely friable and non-adherent, especially on cooling from the flue gas working temperature. The maximum corrosion rate obtained was 70 μm yr–1 for carbon steel, which may be acceptable for a number of flue gas applications. The exposed coupons were examined using conventional techniques such as X-ray diffraction (XRD), optical microscopy (OM) and scanning electron microscopy (SEM). The predominant scale formation mechanism controlling the corrosion appeared to be simple oxidation type reactions, however, the influence of HCl, as evidenced by the presence of akaganeite (β-FeO(OH)), was hypothesised. A model describing the corrosion mechanism is proposed in order to provide an improved life prediction capability for such flue gas environments.

Influence of HCl on the chemical vapor deposition and etching of Ge islands on Si(001)

When HCl is added during the growth of Ge islands on Si(001) by chemical vapor deposition, the reduced Ge surface diffusion impedes island development. There is a shift in the relative populations of different island types even when other conditions such as temperature, coverage, and growth rate, are unchanged. The effect of HCl on the net rate of deposition is proportional to the square of the HCl partial pressure, suggesting a surface reaction with the Ge. When larger islands are etched with HCl at high enough temperature, they revert to a shape characteristic of smaller islands, confirming the reversibility of transformations from one island type to another. It has not proved possible to use etching to produce smaller and more uniform islands.

Influence of aluminum on motility and swarming of Pseudomonas sp. and Arthrobacter sp.

The effect of Al on the motility and the swarming of Pseudomonas sp. and Arthrobacter sp. was investigated. pH calibration curves were determined in semi-solid agar which enabled us to distinguish between the effects of aluminum and protons. Motility of the bacteria was distinctly influenced by Al but this effect could be attributed to the increased acidity accompanying Al addition. The swarming of Pseudomonas sp. is reported for the first time. The swarming ability decreased with both Al and HCl addition to the medium but the obstruction due to aluminum was significantly stronger than the influence of HCl.

Influence of HCL on Rapid Thermal Oxides

AbstractThe influence of HCl on the quality of gate oxides grown by rapid thermal oxidation has been investigated. HCl was added to oxidation ambient for some rapid thermal oxides while for others the silicon surface was annealed in a partial HCl ambient prior to rapid thermal oxidation. Improvements in gate oxide integrity were monitored on MOS capacitors and MOSFET devices by I-V and C-V testing. The levels of chlorine incorporated in the oxide from the addition of HCl to the process was measured by secondary ion mass spectroscopy. Atomic force microscopy was performed to measure surface roughening during HCl pre-oxidation treatments.

Mechanistic study of the selective hydrogenolysis of CCI2F2 (CFC‐12) into CH2F2 (HFC‐32) over palladium on activated carbon

AbstractThe influence of process parameters such as temperature (400‐560K), H2/CCl2F2 ratio (2.2‐20), and Weight Hourly Space Velocity (WHSV) (0.3‐1.0 g/(g · h)) on the hydrogenolysis of CCl2F2 into CH2F2 over palladium on activated carbon has been investigated. The reactivity of CHCIF2 and CH2F2 and the influence of HCl were also examined. In the reaction of CCl2F2, the main product is CH2F2. Significant amounts of CHCIF2 and CH4 are also found. The catalyst shows a remarkably high selectivity to CH2F2, in the range of 70‐90 mol%, at all conversion levels in a broad range of process conditions. A mechanism is proposed in which the reaction proceeds mainly via parallel reaction pathways. One route results in CH2F2 and CHCIF2, while the other route yields CH4. The selectivity to CH2F2 and CHCIF2 is determined by the amount of adsorbed chlorine on the catalytic surface and a constant selectivity for CH4 was found. High selectivity for CH2F2 can be achieved at high H2/CCl2F2 ratios and low HCl concentration. The postulated mechanism is supported by thermodynamic data.

Influence of HCl and Cl2 on the Formation of Polychlorinated Dibenzo-p-dioxins/Dibenzofurans in a Carbon/Fly Ash Mixture

Formation of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) from carbon on incinerator fly ash was investigated using HCI and Cl 2 as a chlorinating agent. The formation proceeds roughly at an equal rate with both gases. These results do not support the theory that chlorination reactions on the fly ash surface take place through free Cl 2 generated by the Deacon reaction. Once formed, PCDD/F remain adsorbed on the fly ash surface until ca. 350°C ; at ca. 400 °C, the major part of these compounds has evaporated from the fly ash to the gas phase.

Influence of HCl on thermal decomposition of PCDDs/PCDFs in fly ash from MSW incinerator

Fly ash from an electrostatic precipitator in a MSW incinerator was heated at 573–773K for 2–60 minutes in various test gases (nitrogen, air or simulated flue gas (O 2 10%, N 2 82%, CO 2 8%)) with or without 500 or 1000ppm HCl and 20% H 2O. Thermal decomposition behavior of PCDDs/PCDFs in fly ash was studied. In any test gas, PCDDs/PCDFs decomposed rapidly at over 673K regardless of HCl presence. Detoxification of PCDDs/PCDFs was more inhibited in simulated flue gas with 1000ppm HCl than in nitrogen or air but concentration of PCDDs/PCDFs decreased to less than 0.01ng-TEQ/g at 773K. Furthermore, it was demonstrated that dioxins in fly ash decomposed almost completely at the bottom of boiler section in a MSW incinerator.

Influence of HCL on polypyrrole films prepared chemically from ferric chloride

AbstractSmooth, adherent films of the electrically conducting polypyrrole formed on surfaces in contact with unstirred aqueous solutions containing the pyrrole monomer and the oxidant, FeCl3. Contradictory reports in the literature concerning the influence of HCl on the growth rate and electrical conductivity of polypyrrole grown in this manner prompted this study of the growth rate and conductivity of films. With no intentional addition of HCl, the growth rate of the films, measured using a quartz crystal microbalance, was fit to a simple second‐order model in which the rate was limited by the bulk depletion of reactants. The conductivity of the films was found to be about 1 S cm−1. Both the growth rate and the electrical conductivity initially increased with the deliberate addition of HCl to the solution. The conductivity was found to peak at a value about 20 S cm−1 at an initial HCl concentration of 0.3 M. At initial HCl concentration of 2M or more, films could not be grown. © 1994 John Wiley & Sons, Inc.

Trace determination of antimony and bismuth in snow and water samples by stripping voltammetry

AbstractSimultaneous determination of antimony and bismuth was performed from 0.5 M HCl solution that contained 0.1 M hydrazine, using the hanging mercury electrode by differential pulse anodic stripping voltammetry with very slow potential scan rate and small pulse amplitude. The influence of HCl and chloride concentrations on the peak shape of Bi and Sb and the influence of other ions and organic substances were investigated. For the determination of antimony and bismuth in water and snow samples, the UV irradiation and the reduction of Sb(V) to SE(III) by hydrazine in boiling solution were applied. The detection limit for Bi and Sb is 20 ng L−1.

Synthesis and rearrangement of 4-imino-4H-3,1-benzoxazines

N-Acylanthranilamides react with dibromotriphenylphosphorane in the presence of triethylamine as HBr captor to give 4-imino-4H-3,1-benzoxazines in good yields. If the reaction is carried out without acid acceptor, N-acetylanthranilamides yield 2-methyl-4-quinazolones, whereas N-benzoylanthranilamides give 2-phenyl-4-imino-4H-3,1-benzoxazines. It has also been found that 2-methyl-4-imino-4H-3,1-benzoxazines rearrange under the influence of HCl or HBr into the respective 2-methyl-4-quinazolones; 2-phenyl-4-imino-4H-3,1-benzoxazines, however, do not undergo such a rearrangement.

The influence of HCl on the oxidation-enhanced diffusion of boron and arsenic in silicon

The influence of HCl on the oxidation-enhanced diffusion of boron and arsenic in silicon has been studied. Experimental data at 1000, 1100, and 1150 °C were obtained using secondary ion mass spectrometry (SIMS). A previously proposed empirical model was used in analyzing the impurity profiles, and the parameters of this model were determined by matching the computer simulations of dopant diffusion with the SIMS profiles. The dependence of the model parameters on temperature and HCl concentration is discussed.

Influence of HCl on the stability of liquid lamellae between two colliding bubbles in aqueous solutions ofn-fatty acids

The effect of HCl on life time of liquid lamellae created between two colliding bubbles in aqueous solutions ofn-fatty acids were studied. The results show, that the addition of HCl has a pronounced influence on life time of the lamellae. At low fatty acid concentration the lifetime of the lamellae in the acidified solution is higher than in the nonacidified solution, but at higher fatty acid concentration the effect reverses. The analysis of these experimental results show that the characteristic influence of HCl on lamellae lifetime can be explained by the formation of distinct association states of the fatty acids in the liquid phase at different concentration ranges. The results are discussed with respect to bubble coalescence in gas-liquid contactors.

Dimerizaticn of 1-vinyl-4,5,6,7-tetrahydroindole under the influence of HCl

Dimerizaticn of 1-vinyl-4,5,6,7-tetrahydroindole under the influence of HCl