Some hydrophysical and hydrochemical parameters of the upper part of the hydrogen sulfide zone in the Black Sea, September 11-22, 1994

Features of spatial variability of hydrogen sulfide in the northeastern part of the Black Sea are estimated. Some technical aspects of H2S concentration determination in the anoxic zone are discussed: in its upper part at H2S concentration <30 µmol/l, the photometric method is recommended, while for deeper layers the iodometric method should be used. With linearity of vertical distribution of hydrogen sulfide and ammonium taken into account their vertical gradients are estimated as 0.49+/-0.04 µmol/m and 0.19+/-0.06 µmol/m respectively. It is shown that the upper boundary of the H2S layer corresponds to the isopycnal surface with Sigma_t = 16.19+/-0.05 arbitrary units. Special attention is paid to relationship of hydrogen sulfide distribution with hydrophysical features in the region under study, in particular in the coastal zone. It is shown that hydrodynamic conditions control spatial distribution of hydrogen sulfide. On the basis of isopycnal treatment of the H2S field existence of a coastal convergence zone is proved, and peculiarities are recognized of vertical circulation in the main Black Sea gyre and coastal anticyclonic eddies; here hydrogen sulfide serves as a tracer of hydrophysical mixing processes.

Letter from William Croswell to Abraham Biglow, 1821 September 11

Draft of a letter regarding the Harvard Library Catalogue.

Letter and account from Phillips Payson to Harvard College, 1780 September 11

These two documents consist of an account of services done by Phillips Payson (1809; Harvard AB 1778) for the College Library and a brief letter of enclosure.

Vote related to the case of Packard, 1780 September 11

One-page handwritten draft of a vote of the Harvard Faculty forwarding the case of Asa Packard (Harvard AB 1783), who advanced money to the College steward on June 3, 1780, to the Corporation. The document is signed by Professor Edward Wigglesworth (1731/2-1794), who served as acting president of the College from 1780 to 1781. The document is missing text.

Oslo terrorist attacks: Analysis, consequences and lessons learned. Transatlantic Security Paper No. 4, August 2011

The attack in Norway, like every attack with a major impact, should and will be carefully analyzed, both by police and by terrorists. If the Norwegian authorities have officially called for a technical evaluation of Counter-terrorism (CT) and rescue national services, many sensitive aspects still remain unsure.