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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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Messier: A Detailed NVM-Based DIMM Model for the SST Simulation Framework.

DRAM technology is the main building block of main memory, however, DRAM scaling is becoming very challenging. The main issues for DRAM scaling are the increasing error rates with each new generation, the geometric and physical constraints of scaling the capacitor part of the DRAM cells, and the high power consumption caused by the continuous need for refreshing cell values. At the same time, emerging Non- Volatile Memory (NVM) technologies, such as Phase-Change Memory (PCM), are emerging as promising replacements for DRAM. NVMs, when compared to current technologies e.g., NAND-based ash, have latencies comparable to DRAM. Additionally, NVMs are non-volatile, which eliminates the need for refresh power and enables persistent memory applications. Finally, NVMs have promising densities and the potential for multi-level cell (MLC) storage.

97 MATHEMATICS AND COMPUTING↗

An infrared system for monitoring Drosophila motility during microgravity

Presently, the precise mechanisms of the aging process are unknown. Examination and comprehension of the aging process in other species could lead to significant advances in the understanding of human aging. Drosophila melanogaster (fruit fly), commonly used for aging studies, is a widely studied organism in terms of behavior, development, and genetics. Previous microgravity experiments have shown a significant decrease in the life span of young male Drosophila after microgravity exposure. This decrease in lifespan may be related to locomotor activity, a convenient measure of overall physiological performance. This study describes the design and performance of a Drosophila Infrared Motility Monitoring System (DIMMS). The DIMMS uses a unique design of two infrared (IR) beams per fly to measure the locomotor activity of 240 flies. Locomotor activity is measured in terms of number of IR crossings per unit time, instantaneous velocity, and continuous velocity. Ground-based results using the DIMMS equipment agree well with previous values for Drosophila locomotor velocity. DIMMS is an improvement over equipment previously used due to its ability to continuously monitor locomotor activity throughout short-duration microgravity exposure. DIMMS is also lightweight, compact, and power efficient. DIMMS has been flight tested onboard NASA's KC-135 reduced gravity research aircraft and a Nike-Orion sounding rocket.

unmanned↗

Seeing values for LSST strategy simulations

The opsim4 operations simulation program for the LSST astronomical survey uses a database of seeing values covering the range of times to besimulated. Idescribethe creation of such a database using Dual Image Motion Monitor(DIMM)datacollected at Cerro Pachon from 2004-03-17 to 2019-10-07. In times during which the data overlap, I compare the distribution of DIMM seeing values to the seeing measured in DECamimages,takenatasite 10kmaway. Becauseinstrumentalproblemsinthe DIMMmay indicate unreliablemeasurements,cutsonimagequality(asindicatedby the measured Strehlratio)wereexplored. TheDIMMhassignificantgaps,soImodel thedata(withandwithoutcutsonStrehlratio)andgenerateartificialdatainthegaps according to the model. The model consists of a sinusoidal variation with a period of one year, an autoregressive (AR1) model for variations in mean seeing from one night to the next, and another AR1 model for variations on a 5 minute timescale. I create four databases according to thisprocedure, twobasedonDIMMdatastarting 2006-01-01 (with and without a Strehl ratio cut), and two starting 2009-01-01. I then run opsim simulations using each, and an otherwise identical simulation using the default seeing database, and explore the differences

Neilsen, Eric H. [Fermilab]↗

Micro-measurements of mechanical properties for adhesives and composites using digital imaging technology

The need for a constituent based durability or accelerated life prediction procedure to be used for the engineering design of polymer matrix composites is discussed in the light of current plans for the High Speed Civil Transport (HSCT) concerns about the U.S. infrastructure (bridges, pipelines, etc.) and other technological considerations of national concern. It is pointed out that good measurement procedures for insitu resin properties are needed for both adhesives and composites. A double cantilever beam (DCB) specimen which shows promise for the easy determination of adhesive shear properties is presented and compared with measurements of strains within the bondline using a new optical digital imaging micro-measurement system (DIMMS). The DCB specimen is also used to assess damage in a bonded joint using a dynamic mechanical thermal analysis system (DMTA). The possible utilization of the same DIMMS and DMTA procedures to determine the insitu properties of the resin in a composite specimen are discussed as well as the use of the procedures to evaluate long term mechanical and physical aging. Finally, a discussion on the state-of-the art of the measurement of strains in micron and sub-micron domains is given.

Brinson, Hal F.↗

NASA Dryden: Flight Loads Lab Capabilities and Mass Properties Testing

This presentation covers the basic capabilities of the Dryden Flight Loads Lab. It also covers in detail the mass properties capabilities of the loads lab, focusing on the recent mass properties testing of the X-48B, and the recent tests of the Dynamic Inertia Measurement method (DIMM). Presentation focuses on the test methods and issues discovered during the mass properties testing of the X-48B leading to the requirement of new instrumentation on all conventional mass properties testing. Presentation also focuses on development of DIMM for replacement of conventional mass properties tests.

Wolfe, David Michael↗

The implementation of Global Feature EXtractor (gFEX) - the ATLAS Calorimeter Level 1 Trigger system for LHC Run-3 upgrade

As part of the ATLAS Phase-I Upgrade, the global Feature EXtractor (gFEX) is one of several hardware modules designed to help maintain the ATLAS Level-1 trigger acceptance rate with the increasing Large Hadron Collider (LHC) luminosity and the increasing Pile-Up conditions. The gFEX is used to identify patterns of energy associated with the hadronic decays of high momentum Higgs, W & Z bosons, top quarks, and exotic particles in real time at the 40 MHz LHC bunch crossing rate. The board is required to receive coarse-granularity (Δη×Δphiv = 0.2×0.2 gTower) information from the entire ATLAS calorimeters on 276 optical fibers. A prototype v1 with one Xilinx ZYNQ FPGA, and one Vertex-7 FPGA for technology validation has been designed and tested in 2015. With the lessons learned from the prototype v1, a prototype v2 with three Vertex UltraScale FPGAs and one ZYNQ FPGA has been implemented to verify full functionalities of gFEX in 2016. Based on the prototype v2 design, a prototype v3, the final gFEX prototype, is implemented, which is an ATCA module consisting of three Vertex UltraScale+ FPGAs, one ZYNQ UltraScale+ SoC, and 35 MiniPODs. This board receives up to 300 fiber optical links from calorimeters and transmits trigger data on 96 links to the to the ATLAS Level-1 Topological trigger (L1Topo [1]) at the speed up to 12.8 Gb/s. There are also 24 electrical links on board for communication between two FPGAs with the speed up to 25.6 Gb/s. The performance of three prototype boards have been tested and evaluated. For the prototype v3 board, the high-speed optical links are stable at 12.8 Gb/s with Bit Error Ratio (BER) < 1 × 10 -15 . The low-latency parallel GPIO (General Purpose I/O) buses between FPGAs are stable at 1.12 Gb/s. The peripheral components of ZYNQ UltraScale+ SoC, such as 16 GB DDR4 DIMM, UART, SPI flashes, and Ethernet, have also been verified. Here, the test results of the prototype v3 board validate the gFEX technologies, architecture and full functionalities. Now the final production board is being produced.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

simsee

Simsee is a program for generating artificial seeing data for simulations of astronomical surveys. It includes a jupyter notebook for deriving model parameters from Dual Image Motion Monitor (DIMM) data, and a program that reads these model parameters and creates a data file suitable for use by survey strategy simulation code (which is outside the scope of this package). It is specifically designed to provide input data for LSST’s opsim4 survey simulator, but may be adapted for use with different simulators as well. The code is verified to work on a Linux workstation with an Intel Xeon E5-6980 CPU and 256GB or memory, but should work fine on systems with far more limited resources.

Neilsen, Eric↗

An Embedded Reconfigurable Logic Module

A Miniature Embedded Reconfigurable Computer and Logic (MERCAL) module has been developed and verified. MERCAL was designed to be a general-purpose, universal module that that can provide significant hardware and software resources to meet the requirements of many of today's complex embedded applications. This is accomplished in the MERCAL module by combining a sub credit card size PC in a DIMM form factor with a XILINX Spartan I1 FPGA. The PC has the ability to download program files to the FPGA to configure it for different hardware functions and to transfer data to and from the FPGA via the PC's ISA bus during run time. The MERCAL module combines, in a compact package, the computational power of a 133 MHz PC with up to 150,000 gate equivalents of digital logic that can be reconfigured by software. The general architecture and functionality of the MERCAL hardware and system software are described.

Tucker, Jerry H.↗

FY12 End of Year Report for NEPP DDR2 Reliability

This document reports the status of the NASA Electronic Parts and Packaging (NEPP) Double Data Rate 2 (DDR2) Reliability effort for FY2012. The task expanded the focus of evaluating reliability effects targeted for device examination. FY11 work highlighted the need to test many more parts and to examine more operating conditions, in order to provide useful recommendations for NASA users of these devices. This year's efforts focused on development of test capabilities, particularly focusing on those that can be used to determine overall lot quality and identify outlier devices, and test methods that can be employed on components for flight use. Flight acceptance of components potentially includes considerable time for up-screening (though this time may not currently be used for much reliability testing). Manufacturers are much more knowledgeable about the relevant reliability mechanisms for each of their devices. We are not in a position to know what the appropriate reliability tests are for any given device, so although reliability testing could be focused for a given device, we are forced to perform a large campaign of reliability tests to identify devices with degraded reliability. With the available up-screening time for NASA parts, it is possible to run many device performance studies. This includes verification of basic datasheet characteristics. Furthermore, it is possible to perform significant pattern sensitivity studies. By doing these studies we can establish higher reliability of flight components. In order to develop these approaches, it is necessary to develop test capability that can identify reliability outliers. To do this we must test many devices to ensure outliers are in the sample, and we must develop characterization capability to measure many different parameters. For FY12 we increased capability for reliability characterization and sample size. We increased sample size this year by moving from loose devices to dual inline memory modules (DIMMs) with an approximate reduction of 20 to 50 times in terms of per device under test (DUT) cost. By increasing sample size we have improved our ability to characterize devices that may be considered reliability outliers. This report provides an update on the effort to improve DDR2 testing capability. Although focused on DDR2, the methods being used can be extended to DDR and DDR3 with relative ease.

Guertin, Steven M.↗

FY12 End of Year Report for NEPP DDR2 Reliability

This document reports the status of the NEPP Double Data Rate 2 (DDR2) Reliability effort for FY2012. The task expanded the focus of evaluating reliability effects targeted for device examination. FY11 work highlighted the need to test many more parts and to examine more operating conditions, in order to provide useful recommendations for NASA users of these devices. In order to develop these approaches, it is necessary to develop test capability that can identify reliability outliers. To do this we must test many devices to ensure outliers are in the sample, and we must develop characterization capability to measure many different parameters. For FY12 we increased capability for reliability characterization and sample size. We increased sample size by moving from loose devices to DIMMs with an approximate reduction of 20 to 50 times in terms of per DUT cost. By increasing sample size we have improved our ability to characterize devices that may be considered reliability outliers. This report provides an update on the effort to improve DDR2 testing capability. Although focused on DDR2, the methods being used can be extended to DDR and DDR3 with relative ease.

temperature stress↗

Electronic component reliability analysis by data reduction system

Mechanized data reduction system has been designed to take advantage of the data handling capacity of computers and to reduce voluminous and unrelated test and performance data to a format useful for the rapid analysis of electronic component reliability.

Dimm, R. M.↗