Isomolybdate conversion coatings

A conversion coating solution and process forms a stable and corrosion-resistant layer on metal substrates or layers or, more preferably, on a boehmite layer or other base conversion coating. The conversion coating process involves contacting the substrate, layer or coating with an aqueous alkali metal isomolybdate solution in order to convert the surface of the substrate, layer or coating to a stable conversion coating. The aqueous alkali metal molybdates are selected from sodium molybdate (Na.sub.2 MoO.sub.4), lithium molybdate (Li.sub.2 MoO.sub.4), potassium molybdate (K.sub.2 MoO.sub.4), or combinations thereof, with the most preferred alkali metal molybdate being sodium molybdate. The concentration of alkali metal molybdates in the solution is preferably less than 5% by weight. In addition to the alkali metal molybdates, the conversion coating solution may include alkaline metal passivators selected from lithium nitrate (LiNO.sub.3), sodium nitrate (NaNO.sub.3), ammonia nitrate (NH.sub.4 NO.sub.3), and combinations thereof; lithium chloride, potassium hexafluorozirconate (K.sub.2 ZrF.sub.6) or potassium hexafluorotitanate (K.sub.2 TiF.sub.6)

Conversion coatings prepared or treated with calcium hydroxide solutions

A conversion coating process that forms a stable and corrosion-resistant oxide layer on metal or metal oxide substrates or layers. Particularly, the conversion coating process involves contacting the metal or metal oxide substrate or layer with the aqueous calcium hydroxide solutions in order to convert the surface of the substrate to a stable metal oxide layer or coating. According to the present invention, the calcium hydroxide solution is prepared by removing carbon dioxide from water or an aqueous solution before introducing the calcium hydroxide. In this manner, formation of calcium carbonate particles is avoided and the porosity of the conversion coating produced by the calcium hydroxide solution is reduced to below about 1%

Less-Toxic Coatings for Inhibiting Corrosion of Aluminum

Two recently invented families of conversion- coating processes have been found to be effective in reducing or preventing corrosion of aluminum alloys. These processes offer less-toxic alternatives to prior conversion-coating processes that are highly effective but have fallen out of favor because they generate chromate wastes, which are toxic and carcinogenic. Specimens subjected to these processes were found to perform well in standard salt-fog corrosion tests

The frequency of Duchenne muscular dystrophy/Becker muscular dystrophy and Pompe disease in children with isolated transaminase elevation: results from the observational VICTORIA study

IntroductionElevated transaminases and/or creatine phosphokinase can indicate underlying muscle disease. Therefore, this study aims to determine the frequency of Duchenne muscular dystrophy/Becker muscular dystrophy (DMD/BMD) in male children and Pompe disease (PD) in male and female children with isolated hypertransaminasemia.MethodsThis multi-center, prospective study enrolled patients aged 3–216 months with serum alanine transaminase (ALT) and/or aspartate transaminase (AST) levels >2× the upper limit of normal (ULN) for ≥3 months. Patients with a known history of liver or muscle disease or physical examination findings suggestive of liver disease were excluded. Patients were screened for creatinine phosphokinase (CPK) levels, and molecular genetic tests for DMD/BMD in male patients and enzyme analysis for PD in male and female patients with elevated CPK levels were performed. Genetic analyses confirmed PD. Demographic, clinical, and laboratory characteristics of the patients were analyzed.ResultsOverall, 589 patients [66.8% male, mean age of 63.4 months (standard deviation: 60.5)] were included. In total, 251 patients (188 male and 63 female) had CPK levels above the ULN. Of the patients assessed, 47% (85/182) of male patients were diagnosed with DMD/BMD and 1% (3/228) of male and female patients were diagnosed with PD. The median ALT, AST, and CPK levels were statistically significantly higher, and the questioned neurological symptoms and previously unnoticed examination findings were more common in DMD/BMD patients than those without DMD/BMD or PD (p < 0.001).DiscussionQuestioning neurological symptoms, conducting a complete physical examination, and testing for CPK levels in patients with isolated hypertransaminasemia will prevent costly and time-consuming investigations for liver diseases and will lead to the diagnosis of occult neuromuscular diseases. Trial RegistrationClinicaltrials.gov NCT04120168

Sorption of barium on kaolinite, montmorillonite and chlorite

The sorption characteristics of the Ba2+ ion on kaolinite, montmorillonite and chlorite type clays were studied using the batch method. Barium-133 was used as a tracer. The Ba2+ ion concentrations ranged from 10–8 to 10–5 mol l–1; synthetic groundwater was used and the grain size of all the solid particles was <40 µm. About 6, 8 and 12 d of shaking were necessary to reach equilibrium for chlorite, kaolinite and montmorillonite, respectively. The sorption isotherms were described best by Freundlich and Dubinin-Radushkevich type isotherms. Sorption was predominantly reversible for kaolinite and partly reversible for montmorillonite and chlorite.Publisher's Versio

Benefits of Education at the Intensive Margin : Childhood Academic Performance and Adult Outcomes among American Immigrants

Using the Children of the Immigrants Longitudinal Study from the United States, this paper examines the association between schooling at the intensive margin and adult outcomes among first- and second-generation American immigrants. Schooling at the intensive margin is measured by reading and math scores in middle school and by GPA scores in both middle and high school. We find that measures of academic performance predict pecuniary and nonpecuniary adult outcomes. We also find that academic performance in high school relative to middle school is important in explaining adult socioeconomic outcomes. Immigrants with higher GPAs in high school compared to middle school have more schooling, are in better health, are less likely to commit crime, and have higher expectations regarding future job prestige and schooling. On the other hand, a decline in GPAs is associated with lower satisfaction with income and occupation. Moreover, our results indicate that infant mortality rate, which is used as a proxy for unfavorable health conditions in the country of birth, has a negative impact on academic performance during childhood and on personal earnings and income satisfaction during adulthood

Benefits of education at the intensive margin: childhood academic performance and adult outcomes among American immigrants

Using the Children of the Immigrants Longitudinal Study (CILS), we examine the associationbetween education at the intensive margin and twenty pecuniary and non-pecuniary adultoutcomes among first- and second-generation American immigrant youth. Education at theintensive margin is measured by two widely used standardized math and reading test scores,national percentile rankings on these tests and cumulative grade point average (GPA) in bothmiddle and high school. Our findings provide evidence that the academic achievement ofimmigrant children in early adolescence is an accurate predictor of later life outcomes. Wealso examine a novel hypothesis that relative academic performance of immigrant children inhigh school compared to middle school, which could be an indicator of change in adolescentaspirations and motivation as well as the degree of adaptation and assimilation to the hostcountry, has an effect on their adult outcomes even after controlling for the levels ofacademic performance in middle and high school. The results suggest that an improvementin GPA from middle school to high school is associated with favorable adult outcomes.Several sensitivity tests confirm the robustness of main findings

Sorption of strontium and barium on clays and soil fractions

Sorption properties of strontium and barium on kaolinte, montmorillonite, chlorite + illite type of mixed clay and soil fractions have been studied by using batch technique at room temperature. 90Sr and 133Ba were used as tracers. Montmorillonite type clay was found to sorb strontium more strongly than the other clays whereas chlorite 4-illite mixed clay was found to be the best sorbent for barium. Variation of distribution ratio, Rd, as a function of cation concentrations exhibited characteristic inverse S-shaped curves. Sorption isoterms were well described by Freundlich and Dubinin-Radushkevich equations in all cases.Hatipoglu Sinan, Eylem Cahit, Göktürk Hale, Erten Hasan N. Sorption of strontium and barium on clays and soil fractions. In: Proceedings of the 9th international Clay Conference, Strasbourg, 1989. Vol II : Surface chemistry. Structure and mixed layering of clays. Strasbourg : Institut de Géologie – Université Louis-Pasteur, 1990. pp. 79-86. (Sciences Géologiques. Mémoire, 86

Sorption of strontium and barium on clays and soil fractions

Sorption properties of strontium and barium on kaolinte, montmorillonite, chlorite + illite type of mixed clay and soil fractions have been studied by using batch technique at room temperature. 90Sr and 133Ba were used as tracers. Montmorillonite type clay was found to sorb strontium more strongly than the other clays whereas chlorite 4-illite mixed clay was found to be the best sorbent for barium. Variation of distribution ratio, Rd, as a function of cation concentrations exhibited characteristic inverse S-shaped curves. Sorption isoterms were well described by Freundlich and Dubinin-Radushkevich equations in all cases.Hatipoglu Sinan, Eylem Cahit, Göktürk Hale, Erten Hasan N. Sorption of strontium and barium on clays and soil fractions. In: Proceedings of the 9th international Clay Conference, Strasbourg, 1989. Vol II : Surface chemistry. Structure and mixed layering of clays. Strasbourg : Institut de Géologie – Université Louis-Pasteur, 1990. pp. 79-86. (Sciences Géologiques. Mémoire, 86