830 research outputs found

    Cryptography Through the Lens of Group Theory

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    Cryptography has been around for many years, and mathematics has been around even longer. When the two subjects were combined, however, both the improvements and attacks on cryptography were prevalent. This paper introduces and performs a comparative analysis of two versions of the ElGamal cryptosystem, both of which use the specific field of mathematics known as group theory

    Alien Registration- Shores, Ella M. (Waterville, Kennebec County)

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    https://digitalmaine.com/alien_docs/15124/thumbnail.jp

    Apollo-Soyuz Doppler-tracking experiment MA-089

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    The Doppler tracking experiment was designed to test the feasibility of improved mapping of the earth's gravity field by the low-low satellite-to-satellite tracking method and to observe variations in the electron density of the ionosphere between the two spacecraft. Data were taken between 1:01 and 14:37 GMT on July 24, 1975. Baseline data taken earlier, while the docking module was still attached to the command and service module, indicated that the equipment operated satisfactorily. The ionospheric data contained in the difference between the Doppler signals at the two frequencies are of excellent quality, resulting in valuable satellite-to-satellite observations, never made before, of wave phenomena in the ionosphere. The gravity data were corrupted by an unexpectedly high noise level of as-yet-undetermined origin, with periods greater than 150 seconds, that prevented unambiguous identification of gravity-anomaly signatures

    ^{63}Cu, ^{35}Cl, and ^{1}H NMR in the S=1/2 Kagom\'e Lattice ZnCu_{3}(OH)_{6}Cl_{2}

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    ZnCu3_{3}(OH)6_{6}Cl2_{2} (S=1/2S=1/2) is a promising new candidate for an ideal Kagom\'e Heisenberg antiferromagnet, because there is no magnetic phase transition down to ∼\sim50 mK. We investigated its local magnetic and lattice environments with NMR techniques. We demonstrate that the intrinsic local spin susceptibility {\it decreases} toward T=0, but that slow freezing of the lattice near ∼\sim50 K, presumably associated with OH bonds, contributes to a large increase of local spin susceptibility and its distribution. Spin dynamics near T=0 obey a power-law behavior in high magnetic fields.Comment: Phys. Rev. Lett. (in press

    Dynamic Scaling in the Susceptibility of the Spin-1\2 Kagome Lattice Antiferromagnet Herbertsmithite

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    The spin-1/2 kagome lattice antiferromagnet herbertsmithite, ZnCu3_{3}(OH)6_{6}Cl2_{2}, is a candidate material for a quantum spin liquid ground state. We show that the magnetic response of this material displays an unusual scaling relation in both the bulk ac susceptibility and the low energy dynamic susceptibility as measured by inelastic neutron scattering. The quantity χTα\chi T^\alpha with α≃0.66\alpha \simeq 0.66 can be expressed as a universal function of H/TH/T or ω/T\omega/T. This scaling is discussed in relation to similar behavior seen in systems influenced by disorder or by the proximity to a quantum critical point.Comment: 5 pages, 3 figures v2: updated to match published version

    The effects of mineral microparticles on dental cell differentiation

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    With the progression of regenerative medicine, bio-fillers are becoming a very viable option in the treatment of dental caries and the repair ofcranio-facial injuries.Manyprevious studies have focused onthe use ofbone marrow stem cells (BMSCs) with micro-Hydroxyapatite (HA) particles. However, there have been mixed reports on these particles having positive or negative effects on cells. This work delves into the effects of micro-HA on BMSCs, 7F2 osteoblasts, and dental pulp stem cells (DPSCs) as well as the effects of micro-Fluorapatite (FA) on these cells.ALP and BCA assays were run for 14 days on to determine ALP specific activity and protein content. Antibody stains andconfocalimaging were done for collagenI and osteocalcin. Control cells produced more protein, osteocalcin, and collagen I, and had higher levels ofALP specific activitywith the exception ofa few spikes in each for cells cultured with microparticles

    Non-Contact Characterization of Container Surfaces

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    Disclosed are systems for non-contact characterization employing laser optical scanning techniques for evaluating surface characteristics of metal products, such as aluminum containers. Laser light is scanned over a surface and distances to the surface are measured and converted to a surface profile, used to identify characteristics in the surface, such as forming defects

    Vesignieite BaCu3V2O8(OH)2 as a Candidate Spin-1/2 Kagome Antiferromagnet

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    A polycrystalline sample of vesignieite BaCu3V2O8(OH)2 comprising a nearly ideal kagome lattice composed of Cu2+ ions carrying spin 1/2 has been synthesized and studied by magnetization and heat capacity measurements. Magnetic susceptibility shows a neither long range order, a spin glass transition nor a spin gap down to 2 K, in spite of a moderately strong antiferromagnetic interaction of J/kB = 53 K between nearest-neighbor spins. A broad peak observed at a temperature corresponding to 0.4J in intrinsic magnetic susceptibility indicates a marked development of the short-range order. The ground state of vesignieite is probably a gapless spin liquid or is accompanied by a very small gap less than J/30.Comment: 4 pages, 5 figure
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