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Microphysical and compositional influences on shortwave radiative forcing of climate by sulfate aerosols

Description: Anthropogenic sulfate aerosols scatter shortwave (solar) radiation iincident upon the atmosphere, thereby exerting a cooling influence on climate relative to pre-industrial times. Previous estimates of this forcing place its global and annual average value at about {minus}1 W M{sup {minus}2}, uncertain to a factor of somewhat more than 2, comparable in magnitude to greenhouse gas forcing over the same period but opposite in sign and much more uncertain. Key sources of uncertainty are atmospheri… more
Date: February 1, 1995
Creator: Schwartz, S. E.; Wagener, R. & Nemesure, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Asynchronous data change notification between database server and accelerator controls system

Description: Database data change notification (DCN) is a commonly used feature. Not all database management systems (DBMS) provide an explicit DCN mechanism. Even for those DBMS's which support DCN (such as Oracle and MS SQL server), some server side and/or client side programming may be required to make the DCN system work. This makes the setup of DCN between database server and interested clients tedious and time consuming. In accelerator control systems, there are many well established software client/s… more
Date: October 10, 2011
Creator: Fu, W.; Morris, J. & Nemesure, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Aerosol sulfate loading and shortwave direct radiative forcing over the North Atlantic Ocean

Description: Shortwave radiative forcing of climate by anthropogenic sulfate aerosols is estimated to be equal in magnitude but opposite in sign to that of greenhouse warming, with a global annual average value of approximately -1 W m{sup -2} uncertain to at least a factor of two. Estimates of the 2 contributions to this forcing by the direct effect are -0.4 W m{sup -2}. It is therefore necessary to accurately and efficiently represent this forcing in climate models, specifically including spatial and tempo… more
Date: March 1, 1997
Creator: Nemesure, S.; Benkovitz, C. M. & Schwartz, S. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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RHIC Injector Complex Online Model Status and Plans

Description: An online modeling system is being developed for the RHIC injector complex, which consists of the Booster, the AGS and the transfer lines connecting the Booster to the AGS and the AGS to RHIC. Historically the injectors have been operated using static values from design specifications or offline model runs, but tighter beam optics constraints required by polarized proton operations (e.g, accelerating with near-integer tunes) have necessitated a more dynamic system. An online model server for th… more
Date: May 4, 2009
Creator: Schoefer ,V.; Ahrens, L.; Brown, K.; Morris, J. & Nemesure, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Quick setup of unit test for accelerator controls system

Description: Testing a single hardware unit of an accelerator control system often requires the setup of a program with graphical user interface. Developing a dedicated application for a specific hardware unit test could be time consuming and the application may become obsolete after the unit tests. This paper documents a methodology for quick design and setup of an interface focused on performing unit tests of accelerator equipment with minimum programming work. The method has three components. The first i… more
Date: March 28, 2011
Creator: Fu, W.; D'Ottavio, T.; Gassner, D.; Nemesure, S. & Morris, J.
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Partner: UNT Libraries Government Documents Department
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Evaluation of sulfate aerosol optical depths over the North Atlantic and comparison with satellite observations

Description: It has been postulated that scattering of sunlight by aerosols can significantly reduce the amount of solar energy absorbed by the climate system. Aerosol measurement programs alone cannot provide all the information needed to evaluate the radiative forcing due to anthropogenic aerosols. Thus, comprehensive global-scale aerosol models, properly validated against surface-based and satellite measurements, are a fundamental tool for evaluating the impacts of aerosols on the planetary radiation bal… more
Date: November 1, 1993
Creator: Berkowitz, C. M.; Ghan, S. J.; Benkovitz, C. M.; Wagener, R.; Nemesure, S. & Schwartz, S. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Cloud-free aerosol optical depth determination over oceans from satellite radiometry

Description: Shortwave radiative forcing of climate by anthropogenic sulfate aerosol has been estimated to be of comparable global-average magnitude, but opposite sign, to longwave forcing by greenhouse gases (Charlson et al., 1992). It is therefore important that this forcing be accurately represented in climate models. Sulfate concentrations calculated by a Global Chemistry Model driven by operational meteorological data (GChM; Benkovitz et al., this meeting) exhibit high spatial and temporal variations t… more
Date: June 1, 1993
Creator: Wagener, R.; Nemesure, S.; Benkovitz, C. M.; Schwartz, S. E.; Berkowitz, C. M. & Ghan, S. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Improved alarm tracking for better accountability

Description: An alarm system is a vital component of any accelerator, as it provides a warning that some element of the system is not functioning properly. The severity and age of the alarm may sometimes signify whether urgent or deferred attention is required. For example, older alarms may be given a lower priority if an assumption is made that someone else is already investigating it, whereas those of higher severity or alarms that are more current may indicate the need for an immediate response. The alar… more
Date: March 28, 2011
Creator: Nemesure, S.; Marr, G.; Shrey, T.; Kling, N.; Hammons, L.; Ingrassia, P. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Improvement plans for the RHIC/AGS on-line model environments

Description: The on-line models for Relativistic Ion Collider (RHIC) and the RHIC pre-injectors (the AGS and the AGS Booster) can be thought of as containing our best collective knowledge of these accelerators. As we improve these on-line models we are building the framework to have a sophisticated model-based controls system. Currently the RHIC on-line model is an integral part of the controls system, providing the interface for tune control, chromaticity control, and non-linear chromaticity control. What … more
Date: August 31, 2009
Creator: Brown, K. A.; Ahrens, L.; Beebe-Wang, J.; Morris, J.; Nemesure, S.; Robert-Demolaize, G. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Beam emittance measurements in RHIC

Description: The RHIC proton polarimeters can operate in scanning mode, giving polarization profiles and transverse beam intensity profile (beam emittance) measurements. The polarimeters function as wire scanners, providing a very good signal/noise ratio and high counting rate. This allows accurate bunch-by-bunch emittance measurements during fast target sweeps (<1 s) through the beam. Very thin carbon strip targets make these measurements practically non-destructive. Bunch by bunch emittance measurement… more
Date: May 4, 2009
Creator: Zelenski,A.; Bazilevsky, A.; Bunce, G.; Gill, R.; Huang, H.; Makdisi, Y. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Commissioning Results of Slow Extraction of Heavy Ions From the AGS Booster.

Description: Brookhaven's AGS Booster has been modified to deliver slow extracted beam to a new beam line, the NASA Space Radiation Laboratory (NSRL). This facility was constructed in collaboration with NASA for the purpose of performing radiation effect studies for the NASA space program. The design of the resonant extraction system has been described in [1]. A more detailed description, which includes predictions of the slow extracted beam time structure has been described in [2]. In this report we w… more
Date: May 12, 2003
Creator: Brown, K. A.; Bellavia, S.; Binello, S.; Brelsford, B.; Dumont, D.; Eng, W. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The RHIC and RHIC Pre-Injectors Controls Systems: Status and Plans

Description: For the past twelve years experiments at the Relativistic Heavy Ion Collider (RHIC) have recorded data from collisions of heavy ions and polarized protons, leading to important discoveries in nuclear physics and the spin dynamics of quarks and gluons. BNL is the site of one of the first and still operating alternating gradient synchrotrons, the AGS, which first operated in 1960. The accelerator controls systems for these instruments span multiple generations of technologies. In this report we w… more
Date: October 10, 2011
Creator: Brown, K. A.; Altinbas, Z.; Aronson, J.; Binello, S.; Campbell, I.; Costanzo, M. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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RHIC Performance During the FY10 200 GeV Au+Au Heavy Ion Run

Description: Since the last successful RHIC Au+Au run in 2007 (Run-7), the RHIC experiments have made numerous detector improvements and upgrades. In order to benefit from the enhanced detector capabilities and to increase the yield of rare events in the acquired heavy ion data a significant increase in luminosity is essential. In Run-7 RHIC achieved an average store luminosity of <L> = 12 x 10{sup 26} cm{sup -2} s{sup -1} by operating with 103 bunches (out of 111 possible), and by squeezing to {beta}… more
Date: May 23, 2010
Creator: Brown, K. A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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