HC1 Solution Research Articles

Continuous Microindentation of Passivated Surfaces in Surface Active Media

ABSTRACTContinuous microindentation tests on electropolished, single crystal Fe(3wt%Si) and Ni surfaces with thin passivation layers exhibit sharp discontinuities in the load-displacement behavior. At the discontinuity, which occurs at a load of 1.8 mN for Fe(3wt%Si) and 0.1 mN for Ni, stresses below the indenter were close to the theoretical strength of the corresponding metal. Microindentation tests performed to loads less than the discontinuity point showed an elastic load-unload behavior. On removing the passive film with a NaCl or HC1 solution, strengths are one to two orders of magnitude smaller in the presence of the chloride ions. On evaporation of the liquid, the load at the discontinuity returned to its initial value due to repassivation, indicative of a passivation oxide layer with varying thickness. This conclusion was verified by ellipsometry. Even though the elastic load-unload behavior on the passivated surface suggests elastic behavior, both elastic finite element and non-linear, elastic perfectly plastic finite element solutions strongly suggest that this might not be the case. Several suggestions as to the reasons for the deviation from continuum theory are presented.

An active neutral metalloproteinase bound to the insoluble collagen in the mineralized phase matrix of adult rat calvaria.

Two kinds of proteinases were found in the mineralized phase matrix of 24-week-old rat calvaria by means of enzymography using gelatin as a substrate. One proteinase was a neutral thiol 58kD proteinase as shown in a previous paper [2]. The other was a neutral metalloproteinase that had a molecular mass of 56kD and was detected only when calcium (Ca) ions were added to the incubation buffer. It is believed that the 56kD proteinase is bound to the insoluble collagen of the bone matrix, as it is solubilized by 4 M guanidine HC1 solution from the insoluble collagen fraction, when prepared by removing extractable proteins of the mineralized phase matrix. The insoluble collagen fraction could also be solubilized and prepared as gelatin by heating at 65 degrees C for 5 minutes. The gelatin was then incubated at 37 degrees C without further treatment and became degraded without an activation of 4-aminophenylmercuric acetate (APMA). This nonactivated degradation was enhanced by adding Ca ions. These results suggest that the 56kD metalloproteinase bound to the insoluble collagen of bone matrix is in an active form and may participate in the rapid degradation of collagen during bone resorption. As partially purified 56kD metalloproteinase degraded cartilage type proteoglycan, but not type I, IV, and V collagens, it is possibly related to the degradation of proteoglycans before it binds to collagen fibers during bone formation.

The effect of aging on the hydrogen-assisted fatigue cracking of a precipitation-hardened Al-Li-Zr alloy

The corrosion fatigue behavior of an Al-2.5 pct Li-0.12 pct Zr alloy has been studied as a function of heat treatment by performing smooth specimen fatigue life experiments on differently aged alloys in dry air and humid nitrogen. Results indicated that aging decreased the fatigue life of the Al-Li-Zr alloy in dry air. However, exposure to water vapor reduced the fatigue resistance of the underaged (UA) alloys but increased the fatigue life of the overaged alloys (OA) alloys. Hydrogen precharging experiments (either exposure to moist air or cathodic charging in HC1 solutions) followed by fatigue testing in dry air confirmed that the UA alloys were susceptible to hydrogen embrittlement and that the OA alloys were insensitive to a hydrogen effect. The experimental results suggest that the susceptibility of the Al-Li-Zr alloy to hydrogen-assisted fracture is essentially related to the effectiveness of hydrogen transport to the region ahead of the crack tip, which is controlled by the microstructure of the alloy. Environmental and aging effects which influence the fatigue characteristics of the studied alloy are discussed.

Effect of 4‐benzylidene, 3‐methyl. 5‐oxo‐1‐phenyl phyrazoline derivatives on the corrosion of aluminium in HC1 solutions

The effect of some pyrazoline derivatives as inhibitors on the dissolution of A1 in 2 mol.L−1 HC1 has been studied by weight‐loss, galvanostatic polarization, polarographic and scanning electron microscopy methods. Additions of Cu2+ Co2+ or Ni2+ ions increases the efficiency of the inhibitors.

論文特集「有機・無機の光機能材料」 光開始によるアミノ基生成を利用するポジ型ホトレジスト 溶解性変化およびホトレジスト感度におけるコモノマーの効果

Pendant acyloxyimino (A0I) groups in photoresists can be photochemically changed into amino groups and by the transformation of amino groups to ammonio groups, the polarity of photoresists can be increased. In this study, effects of comonomers on polarity alteration of photoresists before and after irradiation were investigated. Copolymers of acetophenone oxime Ο-acryloyl ester (AAPO) with styrene (St) or methyl methacrylate (MMA), AAPO (45.6)-St and AAPO(50.3)-MMA, were used as copolymers bearing the pendant AOI g roups. Solubility changes before and after irradation of their films with benzophenone as a sensitizer were examined. Although their films did no dissolve in methanol before irradiation, the AAPO(45.6)-St films treated with an aqueous solution of HC1 after irradiation becam e soluble in a mixture of methanol and water (1: 1 (v/v)), and those of AAPO(50.3)-MMA similarly treated after irradiation dissolved in water. Furthermore, it was found that by the addition of a small amount of the third component, N, N-dimethylacrylamide (DMAA)to a AAPO-St copolymer a difference in polarity of terpolymer before and after irradiation became much greater than that of the AAPO-St copolymer and that the terpolymer showed very high sensitivity as the photoresist.

Aqueous corrosion and oxidation behavior of the Pd-FeCr surface alloys produced by ion beam mixing

Singly charged argon ions are used to intermix sputter-deposited Pd thin films of various thicknesses with the Fe-24Cr substrate alloy. The corrision behavior of these ion beam mixed alloys was studied electrochemically in 0.5M HCI solution (25°C). The oxidation behavior of the same alloys in air at 400°C was studied using Auger depth profiling techniques. Electrochemical measurements indicate that the ion mixed 200 Å Pd/Fe-24Cr alloy passivates for a very short period of time (40 min), after which a negative shift in the electrode potential to the active region occurs due to the dissolution of the thin Pd-enriched surface layer. Prolonged corrosion protection against active dissolution in 0.5M HC1 solution can be achieved in the ion mixed 400 Å Pd/Fe-24Cr and 600 Å Pd/Fe-24Cr surface alloys due to the formation of a thicker Pd-enriched surface layer containing Fe-Cr. The Auger depth profiles revealed that a thick chromium oxide layer tended to form with and on the thicker Pd-enriched surface alloy in air at 400°C.

Representation of the solubility of lead chloride in various chloride solutions with Pitzer’s model

A modified Pitzer’s model[6] has been applied to the representation of the activities of various species in chloride solutions of lead (II). The parameters associated with the representation were the formation constants of four lead chlorocomplexes as well as Pitzer’s interaction parameters. [7] They were determined by treatment of a data base composed of experimental solubilities of lead in NaCl, NH4C1, and HC1 solutions at 25 °C. The root mean square (rms) relative deviations obtained for the representation of the experimental solubilities were 7.8 pct, 5.6 pct, and 5.6 pct for the three systems, respectively. The extension of the model to solubilities in a NaClO4-NaCl solution at an apparent ionic strength of 4 mol/kg water gives a rms relative deviation of 8.9 pct if one parameter involving the perchlorate anion is adjusted. A data treatment of experimental solubilities at other temperatures (from 13 °C to 100 °C) for the systems PbCl2-NaCl-H2O and PbCl2-NH4Cl-H2O has been made to determine the temperature derivatives of Pitzer’s parameters involving complexed ions as well as the variation of solubility and complexation constants with temperature. The resulting rms relative deviation is 9.8 pct.

Protonating power of aqueous and aqueous-alcoholic solutions of HC1 in the presence of inorganic salts

The indicator method has been used to obtain a scale of protonating power of the medium Hos for solutions of HCl in the solvents of constant composition H2O-EtOH-KCl and H2O-NH4Cl at 25‡C. It is shown that in the solvents investigated the value of HOs in HCl is the same as H0 in aqueous solution for the same ratios of the concentrations of HCl and of the basic solvents H2O and EtOH. A method is worked out for estimating the value of\(pK_{BH^{ + ^s } } \) of an organic base in aqueous and aqueous-alcoholic solutions of HCl in the presence of inorganic salts.

A Preliminary Investigation into the Opacifying Effects In Vitro of Compounds with Varying Numbers of Nitrogen-containing Groups using Isolated Porcine Corneas

Isolated intact porcine corneas were incubated for 4 hours with solutions of various compounds, bathing either the epithelial or endothelial surface or both surfaces, and the resulting opacities were measured. All compounds were tested at 5 x 10-4 M, 5 x 10-3 M, 5 x 10 2M and 1 x 10 1M. Solutions of pilocarpine HC1, carteolol HC1 and timolol maleate (which contain 2 or 4 nitrogens) caused a greater opacity when applied to the endothelial surface than when applied to both the endothelial and epithelial surfaces. By contrast, solutions of sodium lauryl sulphate, befunolol HC1 and dibucaine HC1 (which contain 0, 1 or 3 nitrogens) caused a greater opacity when applied to both surfaces than when applied to the endothelial surface alone. In both groups, there was a good correlation between the greatest opacities and the osmolalities of the various solutions. The difference in responses to the two groups of compounds may be related to the number of nitrogen atoms in the molecules. It is suggested that there is something in the porcine corneal epithelium which inhibits the uptake of compounds containing 2 or 4 nitrogens. Alternatively, in the presence of these compounds, the epithelium may be able to actively pump out water that has entered by diffusion. We wish to thank Mrs A.M. Northover for her linguistic assistance, and the local slaughterhouse at Koriyama-shi for the supply of fresh porcine eyes.

Gastric Bleeding and Increased Gastric Vascular Permeability Induced by Platelet Activating Factor (PAF): Effect of Drugs that Affect Arachidonate Metabolism

The injurious effect of platelet activating factor (PAF) on gastric mucosa was studied by measuring bleeding in the acid perfused stomach of anesthetized rats. The effect of PAF on gastric mucosal vascular permeability (GMVP) was assessed by dye-leakage in the saline perfused stomach of anesthetized rats. Intravenous infusion of PAF (100 ng/kg/min for 20 min) apparently caused gastric bleeding under the gastric luminal perfusion with 150 mM HC1 solution, with the peak response at 50-70 min; biopsy indicated the presence of mucosal lesions. GMVP was markedly increased with the peak response at 20-40 min. Pretreatment with CV-3988 (1 or 10 mg/kg, i.v.), a PAF antagonist, dose-dependently blocked the PAF-induced gastric bleeding and increase in GMVP. Pretreatment with hydrocortisone acetate (20 or 40 mg/kg, s.c.) reduced PAF-induced gastric bleeding and increase in GMVP, in contrast to the aggravation by caffeic acid (1 or 5 mg/kg, s.c.). Indomethacin (1 or 5 mg/kg, s.c.) prevented PAF-induced gastric bleeding, and it depressed the increase in GMVP in the case of the lower dose. Prostaglandin E2 (50 or 500 μg/kg, s.c.) significantly reduced PAF-induced gastric bleeding, but had little effect on PAF-induced increase in GMVP. 1-Benzylimidazole (10 or 50 mg/kg, s.c.) also inhibited PAF-induced gastric bleeding and depressed the increase in GMVP at the higher dose. These results suggest that increased GMVP plays a significant role in producing the gastric damage by PAF. Changes in the mucosal level of cyclooxygenase products, especially thromboxanes, by drugs modifying the arachidonate metabolism would be closely associated with their prevention or aggravation of gastric damage induced by PAF.

Chemical durability of some glasses in hydrocyloric acid solution

Chemical durability of some sodium silîcate and sodium boro-silicate glasses in 0.1 N hydrochloric acid solution was studied. The raw materials used were ali of cheınicaliy püre grade and were fincly pulverised. AH nıelts were made in Pt- 2% Rh crucibles in gas furnaces. The temperature of melting ranged from 1400 to 1600°C for four hours. After çomplete melting, the molten glass was annealed at the appropriate temperature; and then the glass was ground usirg agate mortar. AH the measurements of the Chemical durability of the glass powder for each glass sample, was carried out in the usual way using 0.1 N HC1 solution as the immersion solution. The experimental results obtained revealed that the change in the weight loss with the gradual inc- rease of the soda content was attributed to the corrosion rate.

The effect of the elemental sulfur reaction product on the leaching of galena in ferric chloride media

The dissolution of galena in 0.3 M FeCl3-0.3 M HC1 solutions containing 0 to 6 M LiCl was studied at 80 °C, and parabolic kinetics were observed at all LiCl concentrations. The leaching rate increases gradually with increasing LiCl concentrations to ≈4 M LiCl; the presence of >4 M LiCl results in a rapid increase in the leaching rate. The solubility of PbCl2 in 0.3 M FeCl3-0.3 M HC1 solutions containing 0 to 6.5 M LiCl was measured over the temperature range of 50 °C to 90 °C. The solubility increases systematically with increasing temperature and LiCl concentration. The parabolic kinetics, coupled with the correlation between the leaching rate and the solubility of PbCl2, suggest that the dissolution of galena is controlled by the outward diffusion of the PbCl2 reaction product through the constantly thickening layer of elemental sulfur formed during leaching. This conclusion is also supported by various morphological studies which consistently indicated a thin layer of PbCl2 between the corroding galena and the porous elemental sulfur reaction product.

Influence of adrenaline on the onset time of lignocaine anaesthesia

Rat sciatic nerves were employed to investigate the influence of adrenaline on the onset time for anaesthetic blockade induced by 2 per cent lignocaine HCl. The addition of adrenaline at three concentration levels to 2 per cent lignocaine HCl solutions delayed the onset time for conduction blockade.

ホスホン酸ジフェニル‐ホルムアルデヒド樹脂を基体とするイオン交換樹脂に関する研究 （第６報） テトラエチレンペンタミン系含リンキレート樹脂を用いたＰｄ（ＩＩ）の吸着と分離

The adsorption capacity of the titled chelating resin for Pd(II) was about 1.8 mmol/g-R on a dry basis. The rate of adsorption was high and adsorption equilibrium was attained within 15 minutes. The chelating resin showed a good adsorption ability for Pd(II) in the pH 0.5-4.5 region and the selective separation of Pd(II) from other di- and trivalent metal ions is possible by using HC1 solution. The Pt(W) and Pd(II) loaded on the resin can be separated from each other by the elution with 1.0 moll NaOH, followed with 0.5mol/l NaOH- 1.0 wt% KCN solution. The recovery of Pd(II) from sea water and prepared solution containing a large amount of several metal ions was carried out and the concentration ratio for Pd(II) by this resin was excellent.

Determination of Some Characteristic Parameters of Treated Cellophane Membranes

Abstract Membrane potential, water permeation, and electrical resistance of a cellophane membrane treated with NaOH and HC1 solutions have been measured. Some membrane properties, such as permselectivity, hydraulic permeability, and fixed charge concentration in the membrane, were calculated. Variation of hydraulic permeability and the concentration of fixed charge in the membrane with temperature have been also studied. In order to determine the influence of treatment, membrane potentials were measured for a untreated and three differently treated cellophane membranes. A comparation of the fixed charge concentration and permselectivity for treated and untreated membranes was also made. Variation of perm selectivity with concentration was obtained.

THERMODYNAMICS OF CONCENTRATED ELECTROLYTE SOLUTIONS

Abstract A new equation is derived for the activity coefficient of an electrolyte in a liquid solvent (such as water) as a function of electrolyte concentration. This equation contains contributions from long-range electrostatic forces and from short-range attractive forces; it holds from high dilution to the solubility limit. The new equation is based upon extended Debye-Huckel theory for long-range effects and upon the local-composition concept for short-range effects. For a single-electrolyte solution, the new equation contains only one adjustable energy parameter and three other parameters that are ion-specific, not electrolyte-specific. Therefore, extension to multicomponent electrolyte solutions follows without additional assumptions. Ion-specific parameters are reported for H+, K+, Li−, Br− and Cl− ions. Calculated and experimental activity coefficients are in excellent agreement for aqueous solutions of HBr, HC1, KBr, KCl, LiBr and LiCl.

The Electrochemical Response of YBa2Cu3O7-x in Aqueous Solutions

AbstractElectrochemical behavior of a YBa2Cu3O7 (YBCO for short) superconductor was studied by potentiodynamic scanning in different aqueous solutions with 0.1 M concentration. The electrochemical stability of the YBC0 compound was found to be superior in sulfurous acid, NaC1, or KC1 solutions. The dissolution potential in the above solutions ranges from 36 – 92 mV, polarization wasn't possible. However, E raised up to 360 – 960 mV in acids corr solutions with oxidizing potential including suluric, phosphoric and nitric acids indicating a passive behavior. Polarization was observed in sulfuric, sulfurous, and phosphoric acids depicting their potential to be used as etching solutions in lithography of this oxide superconductor. Its electrochemical behavior in HC1 solution is peculiar and informative. It shows three transitions in the polarization curve, corresponding to 272, 756, and 1013 mV, respectively. This is probably related to the transition in the valence states of copper ions during dissolution which is suppressed in the oxidizing acids. In comparison with metallic copper, the YBCO is more stable in the above solutions. The Galvanic current decreases at the order of A1 > Cu > Ag, when the YBC0 is coupled with each of them in 1 M phosphoric acid solution.

Chromatographic properties of zeolites modified for analysis of atmospheric pollutants

Abstract

SYNERGIC EXTRACTION OP HAFNIUM (IV) WITH TTA AND SOLVATING EXTRACTANTS FROM STRONGLY ACIDIC SOLUTIONS

ABSTRACT TBP and dialkyl sulfoxides have been found to bring about synergism when hafnium(IV) is extracted by TTA from concentrated solutions of HCIO4 and HNO3 The synergic complexes extracted were identified as Hf(TTA)3 (CIO4)Si and Hf (TTA) (NO3)3Si, respectively (S = TBP or R2SO4). Synergism reported earlier in the literature for this system in concentrated HC1 solutions could not be confirmed.

Characterization and chemical durability of 70Ph 2SiO·30TiO 2 coating prepared by the sol-gel process

70Ph 2SiO·30TiO 2 coatings on slide glass and phosphate glass substrates have been prepared by the sol-gel process. Experimental results on the characterization and chemical durability of the coatings are presented. It is shown that the coatings heated at 150°C have reasonably good acid and water resistance while their alkali durability is very poor. The XPS results are used to verify the different corrosion behaviors of the coating in pure water and 1N HC1 solutions. The chemical durability of phosphate glass can be significantly improved by this coating.