Four-dimensional modulation and coding: An alternate to frequency-reuse

Four dimensional modulation as a means of improving communication efficiency on the band-limited Gaussian channel, with the four dimensions of signal space constituted by phase orthogonal carriers (cos omega sub c t and sin omega sub c t) simultaneously on space orthogonal electromagnetic waves are discussed. "Frequency reuse' techniques use such polarization orthogonality to reuse the same frequency slot, but the modulation is not treated as four dimensional, rather a product of two-d modulations, e.g., QPSK. It is well known that, higher dimensionality signalling affords possible improvements in the power bandwidth sense. Four-D modulations based upon subsets of lattice-packings in four-D, which afford simplification of encoding and decoding are described. Sets of up to 1024 signals are constructed in four-D, providing a (Nyquist) spectral efficiency of up to 10 bps/Hz. Energy gains over the reuse technique are in the one to three dB range t equal bandwidth

A stability study and moral analysis of a space-station - Centrifuge configuration

Dynamic stability of space station-centrifuge configuratio

African American Literary Traditions in Justina Ireland’s Young Adult Novels Dread Nation and Deathless Divide

Justina Ireland’s young adult novels Dread Nation (2017) and Deathless Divide (2020) tell the story of a Black girl by the name of Jane living in the aftermath of the Civil War, around 1880

Tire stiffness and damping determined from static and free-vibration tests

Stiffness and damping of a nonrolling tire were determined experimentally from both static force-displacement relations and the free-vibration behavior of a cable-suspended platen pressed against the tire periphery. Lateral and force-and-aft spring constants and damping factors of a 49 x 17 size aircraft tire for different tire pressure and vertical loads were measured assuming a rate-independent damping form. In addition, a technique was applied for estimating the magnitude of the tire mass which participates in the vibratory motion of the dynamic tests. Results show that both the lateral and force-and-aft spring constants generally increase with tire pressure but only the latter increased significantly with vertical tire loading. The fore-and-aft spring constants were greater than those in the lateral direction. The static-spring-constant variations were similar to the dynamic variations but exhibited lower magnitudes. Damping was small and insensitive to tire loading. Furthermore, static damping accounted for a significant portion of that found dynamically. Effective tire masses were also small

A Geochemical Assessment of Potential Groundwater Storage Locations within the Yakima River Basin

Currently in the Yakima River Basin more people possess surface water rights than there is available surface water. As a result, the local community devised the Yakima River Basin Integrated Water Management Plan, with the goal of creating a sustainable source of water for the foreseeable future. One of seven elements outlined in this plan is groundwater storage. The idea is to take available water during high spring flows and store it in the subsurface. The water will then be used to increase stream flows and decrease stream water temperatures during the summer months. A main challenge associated with groundwater storage is determining the fate of the recharged water. In this project we analyzed major ions and stable isotopes of surface waters and groundwaters within three regions (Roslyn, Kittitas Valley and Moxee Valley) to determine water–rock interactions, relative residence times, recharge regimes and groundwater surface-water interactions. We found that irrigation water generally had heavier isotopic values (δD \u3e –115‰) and higher nitrogen levels when compared to natural groundwater. This allowed us to identify which aquifers were dominantly recharged by irrigation water versus aquifers that are recharged naturally (typically by snowmelt). Using our geochemical data, combined with known hydrogeologic units and structures we created conceptual models of groundwater relationships at each site. Additionally, we identified potential shallow aquifer recharge sites that have deep surficial aquifers overlain by large vadose zones. These conceptual models and identified locations can be used to inform future management decisions regarding groundwater storage

Design, Characterization, and Additive Manufacturing of Shape Memory Composites

Direct Ink Writing (DIW) is an additive manufacturing method that utilizes a reservoir of fluid that is precisely extruded to construct 3-Dimensional (3D) structures from layering 2-Dimensional (2D) patterns. Fluids used in DIW printing can vary from in-situ, UV-cured resins to thermosetting epoxies that are solidified following the printing process. This thesis explores the latter fluid, specifically those epoxies which possess shape memory abilities. The shape memory function allows a solid, printed component to deform elastically when its temperature exceeds the glass transition temperature (T_g). However, shape memory epoxies traditionally lack the necessary fluid qualities for printing. By forming a composite ink and integrating a network of multiwalled carbon nanotubes (MWCNTs) or carbon black within the uncured fluid profile, the resulting multiphase ink can possess the requisite fluid rheology to facilitate 3D printing through the DIW process. This thesis examines the development and characteristics of two novel DIW inks, one supported by carbon black and the other supported by MWCNTs. In both cases, the composite ink, made printable by either its carbon black or MWCNT content, is further reinforced with VMX24 carbon short fibers. The varying short fiber content revealed various trends in conductivity and mechanical characteristics of the finished 3D printed samples. For the carbon-black based ink, the resulting prints proved themselves to be potential candidates for strain sensors, given their strong electromechanical response at low strain. For both MWCNT- and carbon black-based epoxy inks, the shape memory effect of the base epoxy was retained, resulting in novel DIW inks that are both functional and mechanically resilient

Notes on the Curculionoidea II : 20. A Contribution to the Knowledge of the Curculionoidea

Author Institution: Department of Biology, Long Beach State College, Long Beach 15, Californi

New Rhynchophora. I. (Coleoptera, Anthribidae and Curculionidae)

Author Institution: Department of Zoology and Entomology, The Ohio State University, Columbus 1

Notes on the Curculionoidea : 14. A Contribution to the Knowledge of the Curculionoidea

Author Institution: Department of Zoology and Entomology, The Ohio State University, Columbus 1