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Localized temperature stability in Low Temperature Cofired Ceramics (LTCC)

Hsieh, Lung-Hwa

The base dielectrics of commercial low temperature cofired ceramics (LTCC) systems have a temperature coefficient of resonant frequency ({tau}{sub f}) in the range -50 {approx} -80 ppm/C. In this research we explored a method to realize zero or near zero {tau}{sub f} resonators by incorporating {tau}{sub f} compensating materials locally into a multilayer LTCC structure. To select composition for {tau}{sub f} adjustment, {tau}{sub f} compensating materials with different amount of titanates were formulated, synthesized, and characterized. Chemical interactions and physical compatibility between the {tau}{sub f} modifiers and the host LTCC dielectrics were investigated. Studies on stripline (SL) resonator panels with multiple compensating dielectrics revealed that: 1) compositions using SrTiO{sub 3} provide the largest {tau}{sub f} adjustment among titanates, 2) the {tau}{sub f} compensation is proportional to the amount of SrTiO{sub 3} in compensating materials, as well as the thickness of the compensating layer, and 3) the most effective {tau}{sub f} compensation is achieved when the compensating dielectric is integrated next to the SL. Using the effective dielectric constant of a heterogeneous layered dielectric structure, results from Method of Momentum (MoM) electromagnetic simulations are consistent with the experimental observations.

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TYPE SAND Report YEAR 2012
DOIOSTI

C++ Tensor Toolbox User Manual (V.1.0)

Plantenga, Todd; Kolda, Tamara G.

The C++ Tensor Toolbox is a software package for computing tensor decompositions. It is based on the Matlab Tensor Toolbox, and is particularly optimized for sparse data sets. This user manual briefly overviews tensor decomposition mathematics, software capabilities, and installation of the package. Tensors (also known as multidimensional arrays or N-way arrays) are used in a variety of applications ranging from chemometrics to network analysis. The Tensor Toolbox provides classes for manipulating dense, sparse, and structured tensors in C++. The Toolbox compiles into libraries and is intended for use with custom applications written by users.

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TYPE SAND Report YEAR 2012
DOIOSTI

Postdoctoral program guidelines

Biedermann, Laura B.; Teich-Mcgoldrick, Stephanie; Cruz-Campa, Jose L.; Ekoto, Isaac W.; Ferreira, Summer R.; Hall, Lisa M.; Miller, Andrew W.; Liu, Xiaohua L.; Liu, Yanli L.; Sava Gallis, Dorina F.

We, the Postdoc Professional Development Program (PD2P) leadership team, wrote these postdoc guidelines to be a starting point for communication between new postdocs, their staff mentors, and their managers. These guidelines detail expectations and responsibilities of the three parties, as well as list relevant contacts. The purpose of the Postdoc Program is to bring in talented, creative people who enrich Sandia's environment by performing innovative R&D, as well as by stimulating intellectual curiosity and learning. Postdocs are temporary employees who come to Sandia for career development and advancement reasons. In general, the postdoc term is 1 year, renewable up to five times for a total of six years. However, center practices may vary; check with your manager. At term, a postdoc may apply for a staff position at Sandia or choose to move to university, industry or another lab. It is our vision that those who leave become long-term collaborators and advocates whose relationships with Sandia have a positive effect upon our national constituency.

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TYPE SAND Report YEAR 2012
DOIOSTI

Fun with SFX and stat_object_offline

Ou, Carol

SFX's built-in statistical reports can be handy, but sometimes you might want to slice and dice SFX statistics a little more closely than those reports allow. This session will discuss some preliminary efforts to use the data in SFX's stat{_}object{_}offline table to learn more about our users and how they use SFX.

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TYPE Conference YEAR 2012
OSTI

Modeling the Gila-San Francisco Basin using system dynamics in support of the 2004 Arizona Water Settlement Act

Sun, Amy C.; Tidwell, Vincent C.; Klise, Geoffrey T.

Water resource management requires collaborative solutions that cross institutional and political boundaries. This work describes the development and use of a computer-based tool for assessing the impact of additional water allocation from the Gila River and the San Francisco River prescribed in the 2004 Arizona Water Settlements Act. Between 2005 and 2010, Sandia National Laboratories engaged concerned citizens, local water stakeholders, and key federal and state agencies to collaboratively create the Gila-San Francisco Decision Support Tool. Based on principles of system dynamics, the tool is founded on a hydrologic balance of surface water, groundwater, and their associated coupling between water resources and demands. The tool is fitted with a user interface to facilitate sensitivity studies of various water supply and demand scenarios. The model also projects the consumptive use of water in the region as well as the potential CUFA (Consumptive Use and Forbearance Agreement which stipulates when and where Arizona Water Settlements Act diversions can be made) diversion over a 26-year horizon. Scenarios are selected to enhance our understanding of the potential human impacts on the rivers ecological health in New Mexico; in particular, different case studies thematic to water conservation, water rights, and minimum flow are tested using the model. The impact on potential CUFA diversions, agricultural consumptive use, and surface water availability are assessed relative to the changes imposed in the scenarios. While it has been difficult to gage the acceptance level from the stakeholders, the technical information that the model provides are valuable for facilitating dialogues in the context of the new settlement.

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TYPE SAND Report YEAR 2012
DOIOSTI
Results 66001–66200 of 101,000
Results 66001–66200 of 101,000
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