Resource Type

Month

Anomalous creep in Sn-rich solder joints (open access)

Anomalous creep in Sn-rich solder joints

This paper discusses the creep behavior of example Sn-rich solders that have become candidates for use in Pb-free solder joints. The specific solders discussed are Sn-3.5Ag, Sn-3Ag-0.5Cu, Sn-0.7Cu and Sn-10In-3.1Ag, used in thin joints between Cu and Ni-Au metallized pads.
Date: March 15, 2002
Creator: Song, Ho Geon; Morris, John W., Jr. & Hua, Fay
System: The UNT Digital Library
The new magnetic measurement system at the Advanced Photon Source. (open access)

The new magnetic measurement system at the Advanced Photon Source.

A new system for precise measurements of the field integrals and multipole components of the APS magnetic insertion devices is described. A stretched coil is used to measure magnetic field characteristics. The hardware includes a number of servomotors to move (translate or rotate) the coil and a fast data acquisition board to measure the coil signal. A PC under Linux is used as a control workstation. The user interface is written as a Tcl/tk script; the hardware is accessed from the script through a shared C-library. A description of the hardware system and the control program is given.
Date: March 15, 2002
Creator: Eidelman, Y.; Deriy, B.; Makarov, O. & Vasserman, I.
System: The UNT Digital Library
A numerical study of the impacts of volatile component blending on diesel spray evaporation and combustion. (open access)

A numerical study of the impacts of volatile component blending on diesel spray evaporation and combustion.

A multiphase computational fluid dynamics (CFD) code is used to simulate the evaporation and combustion processes of a diesel spray blended with a highly volatile component. The CFD code uses an Eulerian approach to model the liquid phase of diesel fuel with components of different boiling temperatures. The approach divides the droplets into size groups and assigns different boiling temperatures for each group. The CFD code accounts for liquid droplet flow, turbulent mixing, interfacial drag and heat transfer, droplet evaporation and combustion, radiation heat transfer, and pollutant kinetics. Using the code, a parametric study was conducted to investigate the impacts of a volatile component on the spray evaporation and combustion characteristics. The results indicate that the blending of a highly volatile component can have an impact on droplet evaporation rate and that thermal radiation is significant in spray combustion due to the formation of soot.
Date: March 15, 2002
Creator: Lee, H.L.; Chang, S.L. & Petrick, M.
System: The UNT Digital Library
Overview of the NARSTO-NE-OPS Program. (open access)

Overview of the NARSTO-NE-OPS Program.

The NARSTO-NE-OPS (NorthEast Oxidant and Particle Study) is an investigation of the coupling of the meteorological and chemical processes that control the evolution of air pollution events. The project includes three major field programs carried out at a field site in northeast Philadelphia during the summers of 1998, 1999 and 2001. The activity brings together the research groups from 13 universities, 5 government laboratories and representatives of the electric power industry to apply the most advanced measurement techniques to understanding the physical and chemical processes contributing to air quality issues. Results have been obtained from three ground sites, two instrumented aircraft, many different instrumented balloon platforms, and several remote sensing techniques including satellites. In addition, the database used includes the ground-based measurements conducted at several surrounding state and city operated sites in Pennsylvania, New Jersey, Delaware, New York and Maryland. The results have shown the importance of developing the 3-dimensional regional scale picture of the atmosphere to understand and properly model air pollution events. It has been shown that only from such a perspective, which includes the vertical distribution and a regional context, can one hope to properly model and predict ozone and particulate pollution. A combination of photochemical and …
Date: March 15, 2002
Creator: Philbrick, C. R.; Ryan, W. F.; Clark, R. D.; Doddridge, B. G; Dickerson, R. R.; Gaffney, J. et al.
System: The UNT Digital Library
Report on generation IV technical working group 3 : liquid metal reactors. (open access)

Report on generation IV technical working group 3 : liquid metal reactors.

This paper reports on the first round of R&D roadmap activities of the Generation IV (Gen IV) Technical Working Group (TWG) 3, on liquid metal-cooled reactors. Liquid metal coolants give rise to fast spectrum systems, and thus the reactor systems considered in this TWG are all fast reactors. Gas-cooled fast reactors are considered in the context of TWG 2. As is noted in other Gen IV papers, this first round activity is termed ''screening for potential'', and includes collecting the most complete set of liquid metal reactor/fuel cycle system concepts possible and evaluating the concepts against the Gen IV principles and goals. Those concepts or concept groups that meet the Gen IV principles and which are deemed to have reasonable potential to meet the Gen IV goals will pass to the next round of evaluation. Although we sometimes use the terms ''reactor'' or ''reactor system'' by themselves, the scope of the investigation by TWG 3 includes not only the reactor systems, but very importantly the closed fuel recycle system inevitably required by fast reactors. The response to the DOE Request for Information (RFI) on liquid metal reactor/fuel cycle systems from principal investigators, laboratories, corporations, and other institutions, was robust and …
Date: March 15, 2002
Creator: Lineberry, M. J.; Rosen, S. L. & Sagayama, Y.
System: The UNT Digital Library
SPINning parallel systems software. (open access)

SPINning parallel systems software.

We describe our experiences in using Spin to verify parts of the Multi Purpose Daemon (MPD) parallel process management system. MPD is a distributed collection of processes connected by Unix network sockets. MPD is dynamic processes and connections among them are created and destroyed as MPD is initialized, runs user processes, recovers from faults, and terminates. This dynamic nature is easily expressible in the Spin/Promela framework but poses performance and scalability challenges. We present here the results of expressing some of the parallel algorithms of MPD and executing both simulation and verification runs with Spin.
Date: March 15, 2002
Creator: Matlin, O.S.; Lusk, E. & McCune, W.
System: The UNT Digital Library