Regional geochemical and geophysical surveys in the Berwyn Dome and adjacent areas, north Wales

This report describes stream sediment and gravity surveys carried out across the Berwyn Dome and adjacent areas. The gravity survey confirmed the presence of a broad regional Bouguer anomaly low in the central part of the Dome, on which is superimposed several smaller irregular highs and lows. Some of these local anomalies possibly reflect small igneous bodies but more detailed gravity surveys would be needed to determine their form. Near Corwen the Bryneglwys Fault coincides with a 4.5 mGa1 anomaly but southwards the two features diverge, suggesting that the density interface is related either to a splay fault or to the eastern margin of the Lower Palaeozoic Montgomery trough. Some other structural trends are weakly reflected on the Bouguer anomaly and aeromagnetic maps, but there is no clear correlation with known base metal mineralisation. The Bouguer anomalies cannot be attributed to particular structures with any certainty but are probably due to a number of factors, including variation in the Precambrian basement and changes in the lithology and thickness of Lower Palaeozoic sedimentary rocks. There is no evidence for a large granitic body in Lower Palaeozoic rocks underlying the mineralisation at Llangynog. The aeromagnetic map suggests the presence of a magnetic basement at a depth of 3-4 km centred beneath the northwestern margin of the Dome. The stream sediment survey involved the collection of a - 100 mesh stream sediment, panned concentrate and water sample from each of the 399 sites sampled. The sample density was 1 site per 1.5 km*. Cu, Pb, Zn, Ba, Fe, Mn, Co, V, Cr, Ni, Zr, MO and Sn were determined in the stream sediments, Cu, Pb, Zn, Ba, Fe, Mn, Ce, Sn, Sb, Ti, Ni and As in the panned concentrates and Cu, Pb and Zn in stream waters. Major variations in the results are related to (i) hydrous oxide precipitation processes, (ii) contamination from human activities, (iii) base metal and baryte mineralisation, (iv) monazite concentrations in panned concentrates, (v) hitherto unrecorded gold mineralisation and (vi) lithological variations. The latter were related principally to shale-sandstone variation, but groups of elements attributable to the presence of basic intrusions, phosphatic rocks, coal measures, sandstones, limestones and volcanics were also discerned. Threshold levels were established from cumulative frequency curve analysis, and some anomalous sites were examined in the field. Anomalies did not form prominent coherent groups and were generally weak and scattered, with a wide variety of element groupings reflecting a range of causes. Many anomalous panned concentrates were examined mineralogically to try to . determine whether anomalies were related to chemically extreme background lithologies, contamination, or mineralisation. All the anomalies were related to one or more of the major causes of variation, although because of the very limited amount of follow-up work carried out the precise cause of many anomalies remains uncertain. No anomaly is considered to represent a strong prospect but several deserve further limited investigation, notably those associated with (i) gold mineralisation in the northwest of the area, (ii) baryte, perhaps accompanied by base metal ’ mineralisation, associated with Caradocian volcanics and phosphatic rocks at several localities, (iii) mineralisation associated with Llandeilian limestones and volcanic rocks north of Llanrhaeadr, and (iv) copper mineralisation associated with intrusives near the eastern margin of the Dome, where survey data is most incomplete

Importance of termites in the diet of the aardwolf Proteles cristatus in South Africa

Analysis of 81 faecal samples collected from seven different localities in South Africa revealed that termites are the most important food item in the diet of the aardwolf. Trinervitermes was found to be the most important genus of termite in the faeces from six of the seven localities, whilst other genera of termites, ants, other insects and millipedes mostly occurred as traces in the faeces. No vertebrate remains or traces of carrion were found.Analise van 81 mismonsters uitsewe verskillende omgewings in Suid-Afrika versamel het getoon dat termiete die belangrikste kositem in die die荤t van die aardwolf is. Trinervitermes is die belangrikste termietgenus in die mismonsters uit ses van die sewe omgewings, terwyl slegs spore van ander termietgenera, miere, ander insekte en duisendpote in die mis waargeneem is. Geen werweldier- oorblyfsels of aas is gevind nie

Anomalous Transverse Distribution of Pions as a signal for the production of DCC's

We give evidence that the production of DCC's during a non-equilibrium phase transition can lead to an anomalous transverse distribution of secondary pions when compared to a more conventional boost invariant hydrodynamic flow in local thermal equilibrium. Our results pertain to the linear $\sigma$ model,treated in leading order in large-$N$, in a boost invariant approximation. We also show that the interpolating number density of the field theory calculation plays the role of a classical relativistic phase space number distribution in determining the momentum distribution of pions in the center of mass frame.Comment: 10 pages, LaTex and 3 eps figure

WIPP Waste Characterization: Implementing Regulatory Requirements in the Real World

It is imperative to ensure compliance of the Waste Isolation Pilot Project (WIPP) with applicable statutory and regulatory requirements. In particular, compliance with the waste characterization requirements of the Resource Conservation and Recovery Act (RCRA) and its implementing regulation found at 40 CFR Parts 262,264 and 265 for hazardous and mixed wastes, as well as those of the Atomic Energy Act of 1954, as amended, the Reorganization Plan No. 3 of 1970, the Nuclear Waste Policy Act of 1982, as amended, and the WIPP Land Withdrawal Act, as amended, and their implementing regulations found at 40 CFR Parts 191 and 194 for non-mixed radioactive wastes, are often difficult to ensure at the operational level. For example, where a regulation may limit a waste to a certain concentration, this concentration may be difficult to measure. For example, does the definition of transuranic waste (TRU) as 100 nCi/grain of alpha-emitting transuranic isotopes per gram of waste mean that the radioassay of a waste must show a reading of 100 plus the sampling and measurement error for the waste to be a TRU waste? Although the use of acceptable knowledge to characterize waste is authorized by statute, regulation and DOE Orders, its implementation is similarly beset with difficulty. When is a document or documents sufficient to constitute acceptable knowledge? What standard can be used to determine if knowledge is acceptable for waste characterization purposes? The inherent conflict between waste characterization regulatory requirements and their implementation in the real world, and the resolution of this conflict, will be discussed

Extended Supersymmetries and the Dirac Operator

We consider supersymmetric quantum mechanical systems in arbitrary dimensions on curved spaces with nontrivial gauge fields. The square of the Dirac operator serves as Hamiltonian. We derive a relation between the number of supercharges that exist and restrictions on the geometry of the underlying spaces as well as the admissible gauge field configurations. From the superalgebra with two or more real supercharges we infer the existence of integrability conditions and obtain a corresponding superpotential. This potential can be used to deform the supercharges and to determine zero modes of the Dirac operator. The general results are applied to the Kahler spaces CP^n.Comment: 22 pages, no figure

Water resource implications of the proposed Greenwood Community Forest

The implications for both water use and water quality of the proposed Greenwood Community Forest (Nottinghamshire) are examined. Of the 44000 ha in the designated area, 2700 ha are already afforested and under the proposals up to a further 10000 ha could become afforested. This would change the forest cover of the Sherwood Sandstone outcrop from its present 10% to 25-35%. This is a significant change in land use and will have implications for the quantity and quality of recharge to the underlying aquifer

Image display and background analysis with the Naval Postgraduate School infrared search and target designation system

Characterization, Propagation, and Simulation of Sources and Backgrounds, (1 July 1991)The article of record as published may be found at http://dx.doi.org/10.1117/12.45772Commercial frame grabber technology in IBM PC compatible computers has been adapted to allow direct digital input of InfraRed Search and Track data at rates of up to 10 megabytes per second, permitting realtime processing and display of false color thermal images. Examples of single frame displays and background suppression by frame subtraction are shown. On-board processed fourier spectra and fourier power spectra of selected frame lines are shown. Curve-fitted representations are compared for clear air, cloud and land clutter, and a commercial aircraft at close range.Naval Sea Systems CommandNaval Postgraduate SchoolPMS-42

Effects of Negative Energy Components in the Constituent Quark Model

Relativistic covariance requires that in the constituent quark model for mesons the positive energy states as well as the negative energy states are included. Using relativistic quasi-potential equations the contribution of the negative energy states is studied for the light and charmonium mesons. It is found that these states change the meson mass spectrum significantly but leave its global structure untouched.Comment: 14 pages revtex 3.0, 4 figures uudecoded attached in postscript format, THU-93/1

Mid-infrared entangled photon generation in optimised asymmetric semiconductor quantum wells

The optimal design of asymmetric quantum well structures for generation of entangled photons in the mid-infrared range by spontaneous parametric down- conversion is considered, and the efficiency of this process is estimated. Calcu- lations show that a reasonably good degree of entanglement can be obtained, and that the optical interaction length required for optimal conversion is very short, in the few μm range