Location of pattern-disturbing structures in the vicinity of an antenna Final report, Jun. 5, 1963 - Sep. 15, 1966

Location of radiation pattern disturbing structures in vicinity of satellite antenn

Doping Dependence of Polaron Hopping Energies in La(1-x)Ca(x)MnO(3) (0<= x<= 0.15)

Measurements of the low-frequency (f<= 100 kHz) permittivity at T<= 160 K and dc resistivity (T<= 430 K) are reported for La(1-x)Ca(x)MnO(3) (0<= x<= 0.15). Static dielectric constants are determined from the low-T limiting behavior of the permittivity. The estimated polarizability for bound holes ~ 10^{-22} cm^{-3} implies a radius comparable to the interatomic spacing, consistent with the small polaron picture established from prior transport studies near room temperature and above on nearby compositions. Relaxation peaks in the dielectric loss associated with charge-carrier hopping yield activation energies in good agreement with low-T hopping energies determined from variable-range hopping fits of the dc resistivity. The doping dependence of these energies suggests that the orthorhombic, canted antiferromagnetic ground state tends toward an insulator-metal transition that is not realized due to the formation of the ferromagnetic insulating state near Mn(4+) concentration ~ 0.13.Comment: PRB in press, 5 pages, 6 figure

Sangamonian Forest History and Climate in Atlantic Canada

Seven of the more than twenty five buried organic deposits in Atlantic Canada assigned to pre-Wisconsinan non-glacial intervals possibly relate to the climatic optimum of the Sangamon Interglaciation, that is substage 5e of the deep-sea oxygen isotope record. These sites are East Bay and Green Point on Cape Breton Island. Addington Forks and East Milford in mainland Nova Scotia. Le Bassin and Portage-du-Cap on the Iles de la Madeleine, Québec, and Woody Cove, Newfoundland. Except for Woody Cove, none of the sites records a complete climatic cycle, and the sequence of events must be pieced together from their disparate records. The spectra, characterized by significant amounts of thermophilous taxa that are not as abundant or present in the region today, are similar in general to Holocene spectra at sites immediately south of the lower Great Lakes. Comparison of the fossil spectra from five sites with modern surface spectra from eastern North America yields modern analogs which, if valid, indicate that the climate in Atlantic Canada during the climatic optimum of the last interglacial interval was more continental in character and considerably warmer than present.Des quelque vingt-cinq dépôts organiques enfouis datant d'intervalles non glaciaires pré-wisconsiniens, sept d'entre eux pourraient être attribués à l'optimum climatique de l'Interglaciaire du Sangamonien. c'est-à-dire le stade isotopique 5e. Ces sites sont les suivants: East Bay et Green Point, à l'île du Cap-Breton, Addington Forks et East Milford. en Nouvelle-Ecosse. Le Bassin et Portage-du-Cap, aux îles de la Madeleine, et Woody Cove, à Terre-Neuve. Aucun des sites, sauf celui de Woody Cove, n'a enregistré un cycle climatique complet, et la séquence des événements doit être reconstituée à partir d'inventaires disparates. Les spectres, caractérisés par des quantités importantes de taxons thermophiles qui ne sont plus aussi abondants ou même présents dans la région aujourd'hui, sont semblables de façon générale aux spectres holocènes de sites localisés immédiatement au sud des Grands Lacs inférieurs. La comparaison entre les spectres fossiles de cinq sites et des spectres de surface actuels de l'est de l'Amérique du Nord fait ressortir des sites analogues actuels qui démontreraient que le climat des Maritimes au cours de l'optimum climatique du dernier interglaciaire était plus continental et passablement plus chaud que maintenant.Von den mehr als 25 vergrabenen organischen Ablagerungen im atlantischen Kanada, die prâ-wisconsinischen nichtglazialen Intervallen zugeschrieben werden, gehôren sieben môglicherweise dem klimatischen Optimum des sangamonischen Interglazial an. das heisst Unterphase 5e des Tiefsee-Sauerstoff-lsotop-Belegs. Die sieben Vorkommen sind East Bay und Green Point auf Cape Breton Island, Addington Forks und East Milford auf dem Festland von Nova Scotia. Le Bassin und Portage-du-Cap auf den îles de la Madeleine, Québec, und Woody Cove, Newfoundland. Ausser Woody Cove belegt keiner dieser Plàtze einen ganzen klimatischen Zyklus und die Abfolge der Ereignisse muss aus ihren disparaten Belegen zusammengesetzt werden. Die Spectra, die durch signifikante Mengen von thermophilen Taxa gekennzeichnet sind, welche heute in der Gegend nicht so reichlich vorhanden oder nicht so zugegen sind, àhneln im allgemeinen den Holozàn-Spectra an Plàtzen unmitellbar sùdlich der unteren grossen Seen. Ein Vergleich der Fossil-Sprectra von fùnf Plâtzen mit modernen Oberflâchen-Spectra von Ost Nordamerika liefert moderne Analoge. welche, wenn sie gùltig sind, darauf hinweisen. dass das Klima im atlantischen Kanada wàhrend des klimatischen Optimums des letzten Interglazial einen kontinentalen Charakter hatte und bedeutend warmer war als gegenwàrtig

Development and fabrication of advanced design rate gyro monthly progress report no. 3, 1 - 30 sep. 1963

Design and fabrication of advanced design rate gyro with thin magnesium transducer diaphragm

The Vector Analyzing Power in Elastic Electron-Nucleus Scattering

The vector analyzing power A_n is calculated for elastic electron scattering from a variety of spin zero nuclei at energies from 14 MeV to 3 GeV. Time reversal symmetry insures that A_n vanish in first Born approximation. Therefore A_n depends on Coulomb distortions and can be large for scattering from heavy nuclei. The vector analyzing power is a potential source of systematic error for parity violation experiments. We find that A_n=-0.361 ppm for the kinematics of the Parity Radius Experiment (PREX) involving 850 MeV electrons scattering at six degrees from 208Pb. This is comparable to the parity violating asymmetry. However for HAPPEX He involving 3 GeV electrons scattering on 4He we find that A_n is very small.Comment: 6 pages, 6 figures, submitted to Phys. Rev.

Wave functions in the neighborhood of a toroidal surface; hard vs. soft constraint

The curvature potential arising from confining a particle initially in three-dimensional space onto a curved surface is normally derived in the hard constraint $q \to 0$ limit, with $q$ the degree of freedom normal to the surface. In this work the hard constraint is relaxed, and eigenvalues and wave functions are numerically determined for a particle confined to a thin layer in the neighborhood of a toroidal surface. The hard constraint and finite layer (or soft constraint) quantities are comparable, but both differ markedly from those of the corresponding two dimensional system, indicating that the curvature potential continues to influence the dynamics when the particle is confined to a finite layer. This effect is potentially of consequence to the modelling of curved nanostructures.Comment: 4 pages, no fig

Land Snail Diversity at Rocky Branch Nature Preserve, Clark County, Illinois

Terrestrial, shell-bearing gastropods were collected at Rocky Branch Nature Preserve, Clark County, Illinois. A total of three hundred nineteen specimens were collected representing five families and fifteen species. Two species of the family Endodontidae, eight species of the family Polygyridae, three species of the family Zonitidae, and one species in each of the families Pupillidae and Succineidae were collected. In addition, an attempt was made to find the relationship between species diversity and dominant woody vegetation and soil quality. The land at Rocky Branch Nature Preserve ranges from lowland flood plain to high second growth forest. The dominant trees of the lowland were maple and elm, which produce an alkaline soil with high concentrations of calcium. The dominant trees of the second growth upland forest are oak and hickory, which produce an acid soil and lower calcium concentrations. More specimens of land snails were collected (one hundred and ninety-nine) from the upland forest than from the flood plain (one hundred twenty) . There seemed to be a direct relationship between calcium and pH, but relationship of these two physical properties to organic matter is more complex. Quantitative levels of organic matter appeared meaningless without qualitative data of the tree species involved

Land Snail Diversity at Rocky Branch Nature Preserve, Clark County, Illinois

Terrestrial, shell-bearing gastropods were collected at Rocky Branch Nature Preserve, Clark County, Illinois. A total of three hundred nineteen specimens were collected representing five families and fifteen species. Two species of the family Endodontidae, eight species of the family Polygyridae, three species of the family Zonitidae, and one species in each of the families Pupillidae and Succineidae were collected. In addition, an attempt was made to find the relationship between species diversity and dominant woody vegetation and soil quality. The land at Rocky Branch Nature Preserve ranges from lowland flood plain to high second growth forest. The dominant trees of the lowland were maple and elm, which produce an alkaline soil with high concentrations of calcium. The dominant trees of the second growth upland forest are oak and hickory, which produce an acid soil and lower calcium concentrations. More specimens of land snails were collected (one hundred and ninety-nine) from the upland forest than from the flood plain (one hundred twenty) . There seemed to be a direct relationship between calcium and pH, but relationship of these two physical properties to organic matter is more complex. Quantitative levels of organic matter appeared meaningless without qualitative data of the tree species involved