The Role of Magnesium in Concrete Deterioration, HR-355, Appendix, 1994

In the main report concerning the role that magnesium may have in highway concrete aggregate, over 20,000 electron microprobe data were obtained, primarily from automated scans, or traverses, across dolomite aggregate grains and the adjacent cement paste. Representative traverses were shown in figures and averages of the data were presented in Table II. In this Appendix, detailed representative and selected analyses of carbonate aggregate only are presented. These analyses were not presented in the main report because they would be interesting to only a few specialists in dolomite· rocks. In this Appendix, individual point analyses of mineral compositions in the paste have been omitted along with dolomite compositions at grain boundaries and cracks. Clay minerals and quartz inclusions in the aggregate are also not included. In the analyses, the first three column headings from left to right show line number, x-axis, and y-axis (Line number is an artifact of the computer print-out for each new traverse. Consecutive line numbers indicate a continuous traverse with distances between each point of 1.5 to a few μ-m. X-axis and y-axis are coordinates on the electron microscope stage). The next columns present weight percent oxide content of FeO, K20, CaO, Si02, Al203, MgO, SrO, BaO, MnO, Na20, and C02 (calculated assuming the number of moles of C02 is equal to the sum of moles of oxides, chiefly CaO and MgO), TOTAL (the sum of all oxides), and total (sum of all oxides excluding COi). In many of the analyses total is omitted.

Voyage autour du monde fait dans les années 1803, 1804, 1805 et 1806 par les ordres de sa majesté impériale Alexandre Ier, empereur de Russie, sur les vaisseaux "la Nadiejeda" et "la Neva", commandés par M. de Krusenstern ... traduit, de l'aveu et avec des additions de l'auteur ; la traduction revue par M. J.-B.-B. Eyriès...

Titre original : Reise um die Welt in den Jahren 1803, 1804, 1805 und 1806, auf Befehl seiner... Majestät Alexander des Ersten auf den Schiffen "Nadeshda" und "Newa"

Mechanism of urinary calcium regulation by urinary magnesium and pH.

Urinary magnesium and pH are known to modulate urinary calcium excretion, but the mechanisms underlying these relationships are unknown. In this study, the data from 17 clinical trials in which urinary magnesium and pH were pharmacologically manipulated were analyzed, and it was found that the change in urinary calcium excretion is directly proportional to the change in magnesium excretion and inversely proportional to the change in urine pH; a regression equation was generated to relate these variables (R(2) = 0.58). For further exploration of these relationships, intravenous calcium chloride, magnesium chloride, or vehicle was administered to rats. Magnesium infusion significantly increased urinary calcium excretion (normalized to urinary creatinine), but calcium infusion did not affect magnesium excretion. Parathyroidectomy did not prevent this magnesium-induced hypercalciuria. The effect of magnesium loading on calciuria was still observed after treatment with furosemide, which disrupts calcium and magnesium absorption in the thick ascending limb, suggesting that the effect may be mediated by the distal nephron. The calcium channel TRPV5, normally present in the distal tubule, was expressed in Xenopus oocytes. Calcium uptake by TRPV5 was directly inhibited by magnesium and low pH. In summary, these data are compatible with the hypothesis that urinary magnesium directly inhibits renal calcium absorption, which can be negated by high luminal pH, and that this regulation likely takes place in the distal tubule.

Relationship between macrofauna, mineralogy and exchangeable calcium and magnesium in Cerrado Oxisols under pasture

The objective of this work was to assess the relationship between macrofauna, mineralogy and exchangeable calcium and magnesium in Cerrado Oxisols under pasture. Twelve collection points were chosen in the Distrito Federal and in Formosa municipality, Goiás state, Brazil, representing four soil groups with varied levels of calcium + magnesium and kaolinite/(kaolinite + gibbsite) ratios. Soil macrofauna was collected in triplicate at each collection point, and identified at the level of taxonomic groups. Macrofauna density showed correlation with contents of kaolinite, gibbsite and exchangeable Ca + Mg in the soils. Mineralogy and exchangeable Ca + Mg had significant effects on taxonomic groups and relative density of soil macrofauna. The termites (Isoptera) were more abundant in soils with low exchangeable Ca + Mg; earthworms (Oligochaeta), in soils with high levels of kaolinite; and Hemiptera and Coleoptera larvae were more abundant in gibbsitic soils with higher contents of total carbon.

Nucleophile-Catalyzed Additions to Activated Triple Bonds. Protection of Lactams, Imides, and Nucleosides with MocVinyl and Related Groups

Additions of lactams, imides, (S)-4-benzyl-1,3-oxazolidin-2-one, 2-pyridone, pyrimidine-2,4-diones (AZT derivatives), or inosines to the electron-deficient triple bonds of methyl propynoate, tert-butyl propynoate, 3-butyn-2-one, N-propynoylmorpholine, or N-methoxy-N-methylpropynamide in the presence of many potential catalysts were examined. DABCO and, second, DMAP appeared to be the best (highest reaction rates and E/Z ratios), while RuCl3, RuClCp*(PPh3)2, AuCl, AuCl(PPh3), CuI, and Cu2(OTf)2 were incapable of catalyzing such additions. The groups incorporated (for example, the 2-(methoxycarbonyl)ethenyl group that we name MocVinyl) serve as protecting groups for the above-mentioned heterocyclic CONH or CONHCO moieties. Deprotections were accomplished via exchange with good nucleophiles: the 1-dodecanethiolate anion turned out to be the most general and efficient reagent, but in some particular cases other nucleophiles also worked (e.g., MocVinyl-inosines can be cleaved with succinimide anion). Some structural and mechanistic details have been accounted for with the help of DFT and MP2 calculations.

Journal du marquis de Dangeau. Tome 19 / publié en entier pour la première fois par MM. Soulié, Dussieux, de Chennevières, Mantz, de Montaiglon ; avec les additions inédites du duc de Saint-Simon publiées par M. Feuillet de Conches

Comprend : Additions inédites du duc de Saint-Simon au journal du marquis de Dangeau

Journal du marquis de Dangeau. Tome 2 / publié en entier pour la première fois par MM. Soulié, Dussieux, de Chennevières, Mantz, de Montaiglon ; avec les additions inédites du duc de Saint-Simon publiées par M. Feuillet de Conches

Comprend : Additions inédites du duc de Saint-Simon au journal du marquis de Dangeau

Journal du marquis de Dangeau. Tome 16 / publié en entier pour la première fois par MM. Soulié, Dussieux, de Chennevières, Mantz, de Montaiglon ; avec les additions inédites du duc de Saint-Simon publiées par M. Feuillet de Conches

Comprend : Additions inédites du duc de Saint-Simon au journal du marquis de Dangeau

Journal du marquis de Dangeau. Tome 9 / publié en entier pour la première fois par MM. Soulié, Dussieux, de Chennevières, Mantz, de Montaiglon ; avec les additions inédites du duc de Saint-Simon publiées par M. Feuillet de Conches

Comprend : Additions inédites du duc de Saint-Simon au journal du marquis de Dangeau

Journal du marquis de Dangeau. Tome 14 / publié en entier pour la première fois par MM. Soulié, Dussieux, de Chennevières, Mantz, de Montaiglon ; avec les additions inédites du duc de Saint-Simon publiées par M. Feuillet de Conches

Comprend : Additions inédites du duc de Saint-Simon au journal du marquis de Dangeau

Journal du marquis de Dangeau. Tome 3 / publié en entier pour la première fois par MM. Soulié, Dussieux, de Chennevières, Mantz, de Montaiglon ; avec les additions inédites du duc de Saint-Simon publiées par M. Feuillet de Conches

Comprend : Additions inédites du duc de Saint-Simon au journal du marquis de Dangeau

Journal du marquis de Dangeau. Tome 5 / publié en entier pour la première fois par MM. Soulié, Dussieux, de Chennevières, Mantz, de Montaiglon ; avec les additions inédites du duc de Saint-Simon publiées par M. Feuillet de Conches

Comprend : Additions inédites du duc de Saint-Simon au journal du marquis de Dangeau

Journal du marquis de Dangeau. Tome 4 / publié en entier pour la première fois par MM. Soulié, Dussieux, de Chennevières, Mantz, de Montaiglon ; avec les additions inédites du duc de Saint-Simon publiées par M. Feuillet de Conches

Comprend : Additions inédites du duc de Saint-Simon au journal du marquis de Dangeau