UNOLS establishes SCOAR to promote research aircraft facilities for U.S. ocean sciences

The ocean sciences community is currently engaged in the process of defining new facilities that will support oceanographic research, education, and monitoring efforts for the next several decades. New research vessels, drilling ships, coastal and deep-ocean observing systems, satellites, and submersibles will be designed to increase ocean access in terms of geographical coverage, depth, temporal continuity, and resolution of events. Aircraft may be largely overlooked facilities that are capable of providing observations and data in ways that satisfy many research goals, and they should be considered an important component in the future mix of oceanographic facilities

Eddy covariance measurements of the sea spray aerosol flux over the open ocean

Direct eddy covariance measurements of size-segregated sea spray aerosol fluxes over the open Atlantic Ocean are presented, along with a source function derived from them for a wind speed range of 4 to 18 m s -1 and a size range of 0.176 < R 80 < 6.61 μm. This is in broad agreement with other recent estimates of the source function over this size range but shows a more rapid decrease with size above R 80 = 2 μm than most other functions. The measurements were made during a 3 week cruise in the North Atlantic as part of the UK contribution to the international Surface Ocean-Lower Atmosphere Study (SOLAS) program. They utilized the new high-rate Compact Lightweight Aerosol Spectrometer Probe (CLASP), providing a 16-channel size spectrum (0.17 < R amb < 9.5 μm) at 10 Hz, collocated with a sonic anemometer. The measurements demonstrate the high variability in sea spray aerosol flux compared with other air-sea fluxes, both between individual estimates and in the scales contributing to the flux

Problems with reliability and safety of hot dip galvanized steel structures Problemas com a confiabilidade e segurança de estruturas de aço galvanizadas a quente

Hot dip galvanizing is very effective means of protection against corrosion. Some recommendation concerning the steel quality are generally known and accepted. The process consists of cleaning (pickling or sand blasting) and dipping the structures or pieces into liquid zinc bath. The case study of hot dip galvanized steels is presented. Some recent failures of hot dip galvanized welded structures and hot dip galvanized high strength steel screws are presented. Structures were made of S355 grade steel and MIG/MAG process was applied for welding. Large cracks were observed in the vicinity of welds after hot dip galvanizing process. The presence of both hydrogen and liquid metal embrittlement was identified and associated mainly with higher hardness of HAZ or the quenched and tempered steels. Possible cracking mechanisms are discussed. The influence of chemical composition and production process (welding, heat treatment) was analyzed according to data published in literature. The solutions and recommendations for avoiding the failure in hot dip galvanized structures are proposed.<br>Galvanização a quente é um meio muito efetivo de proteção contra a corrosão. Recomendações relativas a qualidade do aço são geralmente conhecidas e aceitas. O processo consiste de limpar (decapagem ou jateamento) e mergulhar as estruturas ou partes destas em um banho de zinco líquido. O presente trabalho apresenta casos de falhas recentes em estruturas soldadas e em parafusos de aços de alta resistência galvanizados a quente. As estruturas foram fabricadas com aço do grau S355 e o processo MIG/MAG foi usado para a soldagem. Os parafusos foram fabricados com aço de alto carbono. Grandes trincas foram observadas nas proximidades das soldas após o processo de galvanização a quente. A ocorrência de fragilização tanto por hidrogênio como por metal líquido foi identificada e associada com a dureza elevada tanto da ZTA como dos aços temperados e revenidos. Os possíveis mecanismos de fissuração são discutidos. A influência da composição química e processo de fabricação (soldagem e tratamento térmico) é analisada de acordo com dados publicados na literatura. Soluções e recomendações para evitar a falha em estruturas galvanizadas a quente são propostas