830 research outputs found
Cryptography Through the Lens of Group Theory
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)
https://digitalmaine.com/alien_docs/15124/thumbnail.jp
Apollo-Soyuz Doppler-tracking experiment MA-089
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}
ZnCu(OH)Cl () is a promising new candidate for an
ideal Kagom\'e Heisenberg antiferromagnet, because there is no magnetic phase
transition down to 50 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 50 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
The spin-1/2 kagome lattice antiferromagnet herbertsmithite,
ZnCu(OH)Cl, 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 with can be expressed as a
universal function of or . 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
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
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
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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