8,923 research outputs found
"Nearly" Generic Monitoring and Control Programs Maintain Beam Quality
We describe a tool chain that enables experimentation and study of real C++ applications. Our tool chain enables reverse engineering and program analysis by exploiting gcc, and thus accepts any C++ application that can be analysed by the C++ parser and front end of gcc. Our current test suite consists of large, open-source applications with diverse problem domains, including language processing and gaming. Our tool chain is designed using a GXL-based pipe-filter architecture; therefore, the individual applications and libraries that constitute our tool chain each provide a point of access. The preferred point of access is the g4api Application Programming Interface (API), which is located at the end of the chain. g4api provides access to information about the C++ program under study, including information about declarations, such as classes (including template instantiations); namespaces; functions; and variables, statements and some expressions. Access to the information is via either a pointer to the global namespace, or a list interface
Tracer Measurements in Growing Sea Ice Support Convective Gravity Drainage Parameterizations
Gravity drainage is the dominant process redistributing solutes in growing sea ice. Modeling gravity drainage is therefore necessary to predict physical and biogeochemical variables in sea ice. We evaluate seven gravity drainage parameterizations, spanning the range of approaches in the literature, using tracer measurements in a sea ice growth experiment. Artificial sea ice is grown to around 17 cm thickness in a new experimental facility, the Roland von Glasow airâseaâice chamber. We use NaCl (present in the water initially) and rhodamine (injected into the water after 10 cm of sea ice growth) as independent tracers of brine dynamics. We measure vertical profiles of bulk salinity in situ, as well as bulk salinity and rhodamine in discrete samples taken at the end of the experiment. Convective parameterizations that diagnose gravity drainage using Rayleigh numbers outperform a simpler convective parameterization and diffusive parameterizations when compared to observations. This study is the first to numerically model solutes decoupled from salinity using convective gravity drainage parameterizations. Our results show that (1) convective, Rayleigh numberâbased parameterizations are our most accurate and precise tool for predicting sea ice bulk salinity; and (2) these parameterizations can be generalized to brine dynamics parameterizations, and hence can predict the dynamics of any solute in growing sea ic
Pollution in the open oceans: 2009-2013
This review of pollution in the open oceans updates a report on this topic prepared by GESAMP five years previously (Reports and Studies No. 79, GESAMP, 2009). The latter report, the first from GESAMP focusing specifically on the oceans beyond the 200 m depth contour, was prepared for purposes of the Assessment of Assessments, the preparatory phase of a regular process for assessing the state of the marine environment, led jointly by the United Nations Environment Programme (UNEP) and the Intergovernmental Oceanographic Commission (UNESCO-IOC)
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