Spin Blockade in Capacitively Coupled Quantum Dots

We present transport measurements on a lateral double dot produced by combining local anodic oxidation and electron beam lithography. We investigate the tunability of our device and demonstrate, that we can switch between capacitive and tunnel coupling. In the regime of capacitive coupling we observe the phenomenon of spin blockade in a magnetic field and analyze the influence of capacitive interdot coupling on this effect.Comment: 4 pages, 3 figure

Design, fabrication and delivery of a prototype saturator for ACPL

The design configuration and performance characteristics of a saturator developed to provide ground-based simulation for some of the experiments for ACPL-1 first flights of Spacelab are described, some difficulties encountered with the apparatus are discussed, and recommendations concerning testing of this type of instrument are presented. The saturators provide a means of accurately fixing the water vapor mixing ratio of an aerosol sample. Dew point temperatures from almost freezing to ambient room temperatures can be attained with high precision. The instruments can accommodate aerosol flow rates approaching 1000 cc/s. Provisions were made to inject aerosols upstream of these saturators, although downstream injection can be accomplished as well. A device of this type will be used in the ACPL-1 to condition various aerosols delivered concurrently to a CFD, expansion chamber, and static diffusion chamber used in zero gravity cloud-forming experiments. The saturator was designed to meet the requirements projected for the flight instrument

Simulator study of vortex encounters by a twin-engine, commercial, jet transport airplane

A simulator study of vortex encounters was conducted for a twin-engine, commercial, jet transport airplane encountering the vortex flow field of a heavy, four-engine, commercial, jet transport airplane in the final-approach configuration. The encounters were conducted with fixed controls and with a pilot using a state-of-the-art, manual-control system. Piloted encounters with the base-line vortex flow field out of ground effect (unattenuated) resulted in initial bank-angle excursions greater than 40 deg, coupled with initial sideslip-angle excursions greater than 10 deg. The severity of these initial upsets was significantly reduced when the vortex center was moved laterally or vertically away from the flight path of the encountering airplane. Smaller reductions occurred when the flow field was attenuated by the flight spoilers on the generating airplane. The largest reduction in the severity of the initial upsets, however, was from aging in ground effect. The severity of the initial upsets of the following airplane was relatively unaffected by the approach speed. Increasing the lift coefficient of the generating airplane resulted in an increase in the severity of the initial upsets

Higher Algebra

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The Humanization of the Teaching of Mathematics

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Texture in thin film silicides and germanides : a review

Silicides and germanides are compounds consisting of a metal and silicon or germanium. In the microelectronics industry, silicides are the material of choice for contacting silicon based devices (over the years, CoSi2, C54-TiSi2, and NiSi have been adopted), while germanides are considered as a top candidate for contacting future germanium based electronics. Since also strain engineering through the use of Si1-xGex in the source/drain/gate regions of MOSFET devices is an important technique for improving device characteristics in modern Si-based microelectronics industry, a profound understanding of the formation of silicide/germanide contacts to silicon and germanium is of utmost importance. The crystallographic texture of these films, which is defined as the statistical distribution of the orientation of the grains in the film, has been the subject of scientific studies since the 1970s. Different types of texture like epitaxy, axiotaxy, fiber, or combinations thereof have been observed in such films. In recent years, it has become increasingly clear that film texture can have a profound influence on the formation and stability of silicide/germanide contacts, as it controls the type and orientation of grain boundaries (affecting diffusion and agglomeration) and the interface energy (affecting nucleation during the solid-state reaction). Furthermore, the texture also has an impact on the electrical characteristics of the contact, as the orientation and size of individual grains influences functional properties such as contact resistance and sheet resistance and will induce local variations in strain and Schottky barrier height. This review aims to give a comprehensive overview of the scientific work that has been published in the field of texture studies on thin film silicide/germanide contacts. Published by AIP Publishing

MANPOWER IN THE DEVELOPMENT OF THE COAST GUARD NATIONAL SECURITY CUTTER: A HUMAN SYSTEMS INTEGRATION CASE STUDY

The National Security Cutter (NSC) is the U.S. Coast Guard’s (USCG) largest acquisition program to date. Despite the NSC’s significance, its acquisition (2002–present) has suffered numerous performance and cost-related setbacks ostensibly linked to Human System Integration (HSI) issues. In this thesis, we provide a historical HSI case study of the NSC program focusing on manpower, highlighting critical gaps in early concept analyses. While current USCG policy provides definitive guidance on HSI’s inclusion in acquisition programs, little evidence exists linking HSI-related decisions to specific system performance and life-cycle cost outcomes. We use process tracing to systematically establish linkages between USCG HSI policy, NSC program decisions, and specific system performance and life-cycle cost outcomes, illustrating the importance of HSI’s inclusion early in the acquisition life cycle. We produce a template for analyzing HSI decisions and outcomes in large-scale acquisition programs and provide a model for future systems engineering case studies. Our research will guide future program managers and HSI researchers in program management planning endeavors. Finally, our recommendations include the reinforcement of early and iterative HSI tradeoff considerations, organization and program-level integration of HSI in major program integrated product teams, strict adherence to USCG policy-defined HSI-related activities, and purposeful HSI case study taxonomy.Lieutenant Commander, United States Coast GuardApproved for public release. Distribution is unlimited

The Soil Health Properties of Native Grasslands

Due to an increased interest in soil health and the role soils can have in carbon sequestration, native grasslands are getting heightened attention. Native grasslands are known for their deep top-soils that develop over time through the accumulation of soil organic matter. The deep and fibrous root systems that make up two-thirds of the biomass of native grasslands are the primary contributors to the soil organic carbon (SOC) content of grassland soils. Increased SOC content has a cascading effect on soil health metrics through increasing water infiltration and water holding capacity, supporting diverse and abundant soil microbial life, and improving nutrient cycling