A modest all-sky search for narrowband radio radiation near the 21-cm hydrogen line

Since 1973 an all-sky, full-time search for narrowband radio radiation (presumably of intelligent origin) near 21 cm has been underway at the Ohio State University Radio Observatory. The search concentrates on a band 380 kHz wide centered on the hydrogen line, corrected to the Galactic Standard of Rest. The search is limited by lack of funding and personnel. It has been found that beam switching is an important technique for reducing terrestrial interference, and that galactic hydrogen emission does not cause significant extraterrestrial interference. A number of small-diameter cold hydrogen clouds have been discovered. No confirmed narrowband extraterrestrial signals have been found between +48° and +14° in declination above the detection limit of 1.5 × 10^?21 W/m².     

Near–surface ground temperature regime variability in selected microenvironments, Kärkevagge, Swedish Lapland

The importance of topographic microvariability in influencing shallow (10–50 cm depths) soil temperature regimes in arctic–alpine Kärkevagge, northern Sweden, from August 1999 to July 2000 is demonstrated using six sites. The ground microclimate on the tops of very large boulders forming an extensive boulder field in the central valley bottom is more comparable to that at an alpine ridge–crest site 300 m higher than it is to the microclimate at the base of one of the boulders. The boulder crests also differ substantially from the more generalized valley–bottom conditions outside the boulder field. Assuming that chemical processes may be active at temperatures at or above 0°C, sites in the valley experience favorable conditions from 159 to 324 days of the year. Aside from the annual cycle, freeze–thaw cycles are infrequent within Kärkevagge.     

Input sensitivity study of a stratospheric photochemistry model

A general technique for calculating the sensitivities, uncertainties and overall imprecision of a model to a set of input parameters is described and applied to the calculation of CFM induced stratospheric ozone depletion. The input data set used is reaction rates and the technique highlights those that most need further study in the laboratory. The convolution of individual uncertainties to obtain an overall imprecision gives good agreement with the results of Monte-Carlo calculations using the same model.A paper presented at the IAGA/IAMAP Joint Assembly at Seattle, Washington, USA. 22 August–3 September 1977.     

Thermohydromechanical simulations of the natural cooling stage of the Tunnel Sealing Experiment

The Tunnel Sealing Experiment (TSX), located on the 420 Level of the Underground Research Laboratory (URL) of Atomic Energy of Canada Limited (AECL), was used to study the behaviour of two bulkheads installed in situ: one composed of highly compacted bentonite-sand blocks, the other composed of low-heat high-performance concrete. Permeable sand was placed in an 11.2-m-long chamber between the bulkheads. The chamber was first pressurized with water to 4 MPa to simulate the conditions likely to develop in the period following installation of seals in an actual repository. A stage of circulating hot water in the chamber began on 2002 September 24. The maximum design temperature of 85 °C at the interior face of the bulkheads could not be achieved in the time available. The actual maximum temperature was 65 °C. The purpose of heating was to investigate the thermohydromechanical responses in the bulkheads and surrounding rock to increased temperature. A passive cooling stage followed the heating stage. To help understand the influence of natural cooling on the thermohydromechanical response, a series of coupled thermohydromechanical modelling exercises was carried out using the finite element program, Model Of Transport In Fractured/porous media (MOTIF), and the results were compared with measured data. The thermal response in the rock and the bulkheads was successfully simulated. The influence of hydraulic conductivity on the hydraulic response in the clay bulkhead was analyzed.     

Liquidus phase relations on the join diopside-forsterite-anorthite from 1 atm to 20 kbar: Their bearing on the generation and crystallization of basaltic magma

In the system CaO-MgO-Al₂O₃-SiO₂, the tetrahedron CaMgSi₂O₆(di)-Mg₂SiO₄(fo)-SiO₂-CaAl₂ SiO₆(CaTs) forms a simplified basalt tetrahedron, and within this tetrahedron, the plane di-fo-CaAl₂Si₂O₈(an) separates simplified tholeiitic from alkalic basalts. Liquidus phase relations on this join have been studied at 1 atm and at 7, 10, 15, and 20 kbar. The temperature maximum on the 1 atm isobaric quaternary univariant line along which forsterite, diopside, anorthite, and liquid are in equilibrium lies to the SiO₂-rich side of the join di-fo-an. The isobaric quaternary invariant point at which forsterite, diopside, anorthite, spinel, and liquid are in equilibrium passes, with increasing pressure, from the silica-poor to the silica-rich side of the join di-fo-an, which causes the piercing points on this join to change from forsterite+diopside+anorthite+liquid and forsterite +spinel+anorthite+liquid below 5 kbar to forsterite +diopside+spinel+liquid and diopside +spinel+anorthite+liquid above 5 kbar. As pressure increases, the forsterite and anorthite fields contract and the diopside and corundum fields expand. The anorthite primary phase field disappears entirely from the join di-fo-an between 15 and 20 kbar. Below about 4 kbar, the join di-fo-an represents, in simplified form, a thermal divide between alkalic and tholeiitic basalts. From about 4 to at least 12 kbar, alkalic basalts can produce tholeiitic basalts by fractional crystallization, and at pressures above about 12 kbar, it is possible for alkalic basalt to be produced from oceanite by crystallization of both olivine and orthopyroxene. If alkalic basalts are primary melts from a lherzolite mantle, they must be produced at high pressures, probably greater than about 12 kbar.Department of Geosciences, University of Texas at Dallas Contribution No. 327. Hawaii Institute of Geophysics Contribution No. 814.     

Monitoring Flood Extent and Forecasting Excess Runoff Risk with RADARSAT-1 Data

Earth observation from active microwave satellites such as RADARSAT-1 is an excellent tool to monitor and forecast floods. Two complementary approaches are described in this paper: (a) real time or near-real time monitoring of flood extent and (b) mapping of hydrological properties of drainage basins. Since it can penetrate through clouds, which usually occur during precipitation periods, and due to the fact that it can be programmed with different incidence angles, RADARSAT-1 enables frequent coverage over specific areas of interest. It has been used successfully to monitor a major flood of the Red River in Manitoba in 1997, by providing frequent coverage of the flood during its progression and decrease. Resulting data and images have been useful in planning the emergency measures and in assessing flood damage. RADARSAT has also the ability to characterize hydrological properties of watersheds. It has been used in agricultural catchments in Europe for mapping soil surface roughness, which affects runoff coefficients, concentration time and resistance to erosion processes. Used to complement optical data, RADARSAT has provided information on the status of land use and soil protective cover in drainage basins. This information can then be translated into parameters and coefficients that hydrological models can use for runoff and flood forecasting     

Encapsulation of limestone waste in concrete after arsenic removal from drinking water

Arsenic is one of the many naturally occurring contaminants in drinking water. Although various treatment technologies can remove arsenic, most suffer from a common problem of disposal of arsenic-enriched waste after treatment. This project focused on improving a limestone-based disposal technique by encapsulating the arsenic-enriched limestone waste in concrete. The research work determined the compressive strengths of the concrete cubes prepared using treated limestone after arsenic removal and determined the amount of leaching from the arsenic-encapsulated concrete. The removal of arsenic was done with batch experiments using 0.5–1 mm sized Minnekahta Limestone. The efficiency of the limestone in removing arsenic ranged from 85.9 to 95.5%. The amount of arsenic adsorbed onto the surface of each gram of limestone ranged from 0.8 to 3.9 μg. Compressive strength results of concrete cubes prepared by incorporating arsenic-enriched limestone showed typical strength curves at 1, 3, 7 and 28 days. Leaching of arsenic was less than 0.05 mg/L, which is 1/100 of the US Environmental Protection Agency’s standard for disposal of arsenic in a landfill. Hence, encapsulating the arsenic-enriched limestone in concrete has potential for recycling the waste material, thereby reducing disposal costs of the limestone-based removal method.     

Appropriate aspirations for effective post-mining restoration and rehabilitation: a response to Kaźmierczak et al.

Confusion surrounding the definition and application of terminology in post-mining ecological repair has resulted in uncertainty for industry, the scientific community and regulators. This lack of clarity may underrepresent high aspirations or could be misused to disguise low aspirations and so is problematic for setting objectives, establishing goals and assessing recovery trajectories. We respond to a recently published analysis of the ecosystem repair literature, where we highlight inconsistencies stemming from inadequate reference to a large proportion of the restoration and rehabilitation literature. We outline increasingly well-accepted and internationally applied definitions concerning the restoration and recovery process and invite both the mining industry and policy-makers to re-examine their terminology in the interests of attaining an internationally agreed nomenclature. Clarity in the use and understanding of terminology will align post-mining targets with community expectation, enhance the capacity of the mining industry to understand and meet these targets, and foster better analysis and more industry-relevant discussion of recovery methodologies by the scientific community and practitioners.