Superconducting Cosmc Strings and Primordial Magnetic Fields

We consider grand unified theories with superconducting cosmic strings and which admit the mechanism for generating primordial magnetic fields recently discussed by Vachaspati. We show that these models are severely constrained by cosmological arguments. Quite generically, either stable springs or vortons will form. Provided the mass per unit length of the strings is sufficiently large, these stable configurations will overclose the Universe.Comment: BROWN-HET-830, 14 pages, use phyzz

Land Grant Application- Davis, Allen (Minot)

Land grant application submitted to the Maine Land Office for Allen Davis for service in the Revolutionary War.https://digitalmaine.com/revolutionary_war_me_land_office/1241/thumbnail.jp

Inflation in Supersymmetric Cosmic String Theories

We examine a non-Abelian SUSY $SU(2) \times U(1)$ gauge theory and a SUSY U(1) theory originally used to investigate the microphysics of cosmic strings in supersymmetric theories. We show that both theories automatically include hybrid inflation. In the latter theory we use a $D$ term to break the symmetry. SUSY is broken during inflation and restored afterwards. Cosmic strings are formed at the end of inflation. The temperature anisotropy is calculated and found to vary as $(M_{GUT}/M_P)^2$.Comment: 5 page

OPTIMIZATION OF TRANSITION-METAL INCLUSIVE CARBON AEROGELS FOR ELECTROCHEMICAL ENERGY APPLICATIONS

The ever-growing need for energy alongside rising concerns for climate change demands the development of renewable energy technologies. Hydrogen fuel cells are a promising technology that can serve to either supplement energy generation or act as a lone power source. Yet for these devices to be truly green, the hydrogen that serves as fuel must be procured from a renewable resource. Electrolytic water splitting is a process that allows for the dissociation of water into H2 and O2. For this process to be practical, the electrolyzer needs to demonstrate high efficiency and stability, as well as a low overhead cost. Towards this end, transition-metal-based electrocatalysts demonstrate the desired properties. In this study, transition-metal inclusive carbon aerogels (RF-CTm) were initially synthesized by adding nickel acetate (RF-CNi), cobalt acetate (RF-CCo), or a 1:1 weight ratio of both (RF-CCoNi) to a resorcinol-formaldehyde (RF) hydrogel synthesis. The resulting hydrogels were then lyophilized to create their respective aerogels, followed by a calcination process to carbonize them. After synthesis, the various samples were employed towards electrode construction for use as bifunctional electrocatalysts. Furthermore, the initial success of RF-CCoNi encouraged the creation of more samples, which modified the wt.% of the 1:1 metal mixture added to the hydrogel synthesis. Initial electrochemical testing demonstrated that the materials possessed a high affinity for the oxygen evolution reaction, with RF-C, RF-CCo, RF-CNi, and RF-CCoNi producing low overpotentials of 320, 360, 330, and 310 mV respectively. Additionally, these materials processed the reaction at a high rate, with corresponding Tafel slopes being 79, 65, 65, and 47 mV/dec. Meanwhile, the material provided solid results for the hydrogen evolution reaction, demonstrating overpotentials of 236, 207, 202, and 141 mV alongside Tafel slopes of 203, 168, 142, and 131 mV/dec. Considering the promising results of RF-CCoNi, further testing explored the adjustment of overall metal content added to the aerogel. The resulting samples, delineated as RF-CCoNi 25%, RF-CCoNi 50%, RF-CCoNi 75%, and RF-CCoNi 150% demonstrated oxygen evolution and hydrogen evolution overpotentials of 310, 370, 360, 360, and 188, 134, 158, 340 mV each. The results from these experiments advocate that RF-CCoNi aerogels possess desirable properties as a bifunctional electrocatalyst for water electrolysis

Precision Weed Management Based on UAS Image Streams, Machine Learning, and PWM Sprayers

Weed populations in agricultural production fields are often scattered and unevenly distributed; however, herbicides are broadcast across fields evenly. Although effective, in the case of post-emergent herbicides, exceedingly more pesticides are used than necessary. A novel weed detection and control workflow was evaluated targeting Palmer amaranth in soybean (Glycine max) fields. High spatial resolution (0.4 cm) unmanned aircraft system (UAS) image streams were collected, annotated, and used to train 16 object detection convolutional neural networks (CNNs; RetinaNet, Faster R-CNN, Single Shot Detector, and YOLO v3) each trained on imagery with 0.4, 0.6, 0.8, and 1.2 cm spatial resolutions. Models were evaluated on imagery from four production fields containing approximately 7,800 weeds. The highest performing model was Faster R-CNN trained on 0.4 cm imagery (precision = 0.86, recall = 0.98, and F1-score = 0.91). A site-specific workflow leveraging the highest performing trained CNN models was evaluated in replicated field trials. Weed control (%) was compared between a broadcast treatment and the proposed site-specific workflow which was applied using a pulse-width modulated (PWM) sprayer. Results indicate no statistical (p \u3c .05) difference in weed control measured one (M = 96.22%, SD = 3.90 and M = 90.10%, SD = 9.96), two (M = 95.15%, SD = 5.34 and M = 89.64%, SD = 8.58), and three weeks (M = 88.55, SD = 11.07 and M = 81.78%, SD = 13.05) after application between broadcast and site-specific treatments, respectively. Furthermore, there was a significant (p \u3c 0.05) 48% mean reduction in applied area (m2) between broadcast and site-specific treatments across both years. Equivalent post application efficacy can be achieved with significant reductions in herbicides if weeds are targeted through site-specific applications. Site-specific weed maps can be generated and executed using accessible technologies like UAS, open-source CNNs, and PWM sprayers

Body Limb Movement Limiter

A body limb movement limiter restrains the movement of a person\u27s arm so as to protect the person\u27s shoulder or restrains the movement of a person\u27s lower leg with respect to the upper leg so as to protect the person\u27s knee. The device uses a housing having a reel disposed therein with a tether attached thereto and a shear thickening non-Newtonian fluid disposed within the housing so that the fluid acts on the reel during a payout procedure of the tether. The housing is attached to a strap secured about the torso of the person while the free end of the tether is secured about the person\u27s arm. Alternately, a pair of arms are pivotally secured to each other within a housing having the non-Newtonian fluid therein for limiting movement of one arm with respect to the other

Apparatus for Removal of Minute Particles from a Surface Using Thermophoresis to Prevent Particle Redeposition

A method and apparatus for removing minute particles from a surface of a sample are provided that prevent redeposition of the particles onto the surface. By combining thermophoresis with laser assisted particle removal (LAPR), the methods and apparatus remove minute particles (for example, micrometer and nanometer sizes) and assure that they will not redeposit