152 research outputs found

    The "Carex" fen vegetation of northern New South Wales

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    The floristic composition and extent of Carex-dominated fens in the New South Wales New England Tablelands Bioregion and Barrington Tops area (lat 28° 41’ S–31° 55’ S; long 151° 23’ E–152° 05’ E) together with outliers from the central west (Coonabarabran) are described from 81 full floristic survey sites. These fens contained 234 vascular plant taxa of which 27% were exotic. The fens were dominated by herbaceous vegetation (96% of taxa). Cluster analysis of cover-abundance scores of vascular plant taxa from 81 plots placed within 71 separate Carex fens revealed three alliances: 1) Carex appressa, 2) Scirpus polystachyus – Carex tereticaulis and 3) Carex gaudichaudiana and seven communities: (1) Carex appressa – Stellaria angustifolia Fen (2) Carex appressa Fen (3) Scirpus polystachyus – Carex appressa Fen (4) Carex tereticaulis Fen (5) Carex gaudichaudiana – Isachne globosa Fen (6) Carex sp. Bendemeer – Carex gaudichaudiana Fen (7) Carex gaudichaudiana – Glyceria australis Fen The distribution of alliances showed a pattern of east-west separation. The most easterly alliance shares many features with the Carex gaudichaudiana Alliance of the Monaro Region of southern NSW while the other alliances have no counterparts within the current literature. We estimate that up to 5 000 ha of fen vegetation survive in the New England Bioregion of which 90% is on grazed land and only 0.2% is within conservation reserves. Seven outstanding examples of fens remain; most are examples of Community 5, with one representing Community 6 and none representing the other five communities. Many of these are not secured, and none of those within reserves are in their ‘natural’ state. We therefore strongly encourage measures to allow closure of drains, the opening of dams, and the rehabilitation of important fens such as Bishops, Racecourse and New Country Swamps

    Vegetation of montane bogs in east-flowing catchments of northern New England, New South Wales

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    The floristics of the montane bogs in east-flowing catchments of northern New England, north-eastern New South Wales (lat 28° 47’–31° 25’ S; long 151° 50’–152° 30’ E), are described from 62 full floristic survey sites (20 x 20 m in area). Eight vegetation communities are based on flexible UPGMA analysis of cover-abundance scores of vascular plant taxa. Shrub species make up 26% of the flora and herb species 69%, with the remaining taxa trees, climbers or vines. Shrub species were of little diagnostic value, as a few common dominants were shared across most communities. The herbaceous layer was found to be of better circumscriptive value. Communities described (based on dominant herbaceous species) are: (1) Themeda australis – Gonocarpus micranthus, (2) Baumea articulata – Baloskion stenocoleum, (3) Lepidosperma limicola – Baloskion stenocoleum, (4) Baloskion fimbriatum – Lomandra longifolia, (5) Lepyrodia scariosa – Blandfordia grandiflora, (6) Lepidosperma gunnii – Lepidosperma scariosa, (7) Baloskion stenocoleum – Empodisma minus, (8) Lepidosperma limicola – Xyris operculata. The mean annual moisture index was found to account for 26% of the variation in species density. These montane bog systems are some of the richest in Australia, with a high number of rare and restricted taxa. They are vulnerable to both present landuse practices and future changes in climate, are restricted in area, and need further conservation efforts to ensure their long-term survival

    The search for liberty in the theatre of Alfonso Sastre

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    Alfonso Sastre, born in 1926, was a child during the Spanish Civil War. His temperament and personality were shaped by a Spain in the state of transition. He has seen coups d\u27états, dictatorship, a republic and monarchy. With each change of government Spain was searching for a way to unite her divided self, a self which had been divided since the Moors invaded Spain in the eighth century. Sastre has reflected Spain\u27s search for liberty and has produced what he calls a Theatre of Social Agitation, the fundamental theme of which is revolution. With this type of theatre Sastre proposes to stir the conscience of the Spanish people to the urgency of the need for social action. He expresses in his teatre a profound concern in finding a metaphor for modern man, man left face to face with himself . Man has been left in such a state because in rejecting God to become God Himself, he has cut himself off from his metaphysical and spiritual roots. Proponents of the God is dead philosophy stress that man must become God in order to create the society in which man can exist independently of God Almighty. Through his characters Alfonso Sastre questions man\u27s capacity to exist in a society blighted with social hypocrisy, political injustice, and moral corruption. Each of the protagonists in the plays selected for this thesis seeks to change the status quo through revolutionary means, because present conditions are interfering with his acceptance of his sense of self. The nature of the forces which restrict modern man has frustrated him to the point where he must either act or be annihilated

    Montane lakes (lagoons) of the New England Tablelands Bioregion

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    The vegetation of montane lagoons of the New England Tablelands Bioregion, New South Wales is examined using flexible UPGMA analysis of frequency scores on all vascular plant taxa, charophytes and one liverworts. Seven communities are described: 1. Hydrocotyle tripartita – Isotoma fluviatilis – Ranunculus inundatus – Lilaeopsis polyantha herbfield; 2. Eleocharis sphacelata – Potamogeton tricarinatus sedgeland; 3. Eleocharis sphacelata – Utricularia australis – Isolepis fluitans, herbfield; 4. Utricularia australis – Nitella sonderi herbfield; 5. Eleocharis sphacelata – Utricularia australis – Ricciocarpus natans sedgeland; 6. Carex gaudichaudiana – Holcus lanatus – Stellaria angustifolia sedgeland; 7. Cyperus sphaeroides – Eleocharis gracilis – Schoenus apogon – Carex gaudichaudiana sedgeland. 58 lagoons were located and identified, only 28% of which are considered to be intact and in good condition. Two threatened species (Aldovandra vesiculosa and Arthaxon hispidus) and three RoTAP-listed taxa were encountered during the survey

    Miniaturized metal (metal alloy)/ PdO.sub.x/SiC hydrogen and hydrocarbon gas sensors

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    A miniaturized Schottky diode hydrogen and hydrocarbon sensor and the method of making same is disclosed and claimed. The sensor comprises a catalytic metal layer, such as palladium, a silicon carbide substrate layer and a thin barrier layer in between the catalytic and substrate layers made of palladium oxide (PdO.sub.x). This highly stable device provides sensitive gas detection at temperatures ranging from at least 450 to 600.degree. C. The barrier layer prevents reactions between the catalytic metal layer and the substrate layer. Conventional semiconductor fabrication techniques are used to fabricate the small-sized sensors. The use of a thicker palladium oxide barrier layer for other semiconductor structures such as a capacitor and transistor structures is also disclosed

    Miniaturized metal (metal alloy)/ PdO.sub.x/SiC hydrogen and hydrocarbon gas sensors

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    A miniaturized Schottky diode hydrogen and hydrocarbon sensor and the method of making same is disclosed and claimed. The sensor comprises a catalytic metal layer, such as palladium, a silicon carbide substrate layer and a thin barrier layer in between the catalytic and substrate layers made of palladium oxide (PdO.sub.x ). This highly stable device provides sensitive gas detection at temperatures ranging from at least 450 to 600.degree. C. The barrier layer prevents reactions between the catalytic metal layer and the substrate layer. Conventional semiconductor fabrication techniques are used to fabricate the small-sized sensors. The use of a thicker palladium oxide barrier layer for other semiconductor structures such as a capacitor and transistor structures is also disclosed

    Miniaturized Metal (Metal Alloy)/PdO(x)/SiC Hydrogen and Hydrocarbon Gas Sensors

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    A miniaturized Schottky diode hydrogen and hydrocarbon sensor and the method of making same is disclosed and claimed. The sensor comprises a catalytic metal layer, such as palladium, a silicon carbide substrate layer and a thin barrier layer in between the catalytic and substrate layers made of palladium oxide (PdO(x)). This highly stable device provides sensitive gas detection at temperatures ranging from at least 450 to 600 C. The barrier layer prevents reactions between the catalytic metal layer and the substrate layer. Conventional semiconductor fabrication techniques are used to fabricate the small-sided sensors. The use of a thicker palladium oxide barrier layer for other semiconductor structures such as a capacitor and transistor structures is also disclosed

    Catalytic-Metal/PdO(sub x)/SiC Schottky-Diode Gas Sensors

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    Miniaturized hydrogen- and hydrocarbon-gas sensors, heretofore often consisting of Schottky diodes based on catalytic metal in contact with SiC, can be improved by incorporating palladium oxide (PdOx, where 0 less than or equal to x less than or equal to 1) between the catalytic metal and the SiC. In prior such sensors in which the catalytic metal was the alloy PdCr, diffusion and the consequent formation of oxides and silicides of Pd and Cr during operation at high temperature were observed to cause loss of sensitivity. However, it was also observed that any PdOx layers that formed and remained at PdCr/SiC interfaces acted as barriers to diffusion, preventing further deterioration by preventing the subsequent formation of metal silicides. In the present improvement, the lesson learned from these observations is applied by placing PdOx at the catalytic metal/SiC interfaces in a controlled and uniform manner to form stable diffusion barriers that prevent formation of metal silicides. A major advantage of PdOx over other candidate diffusion-barrier materials is that PdOx is a highly stable oxide that can be incorporated into gas sensor structures by use of deposition techniques that are standard in the semiconductor industry. The PdOx layer can be used in a gas sensor structure for improved sensor stability, while maintaining sensitivity. For example, in proof-of-concept experiments, Pt/PdOx/SiC Schottky-diode gas sensors were fabricated and tested. The fabrication process included controlled sputter deposition of PdOx to a thickness of 50 Angstroms on a 400-m-thick SiC substrate, followed by deposition of Pt to a thickness of 450 Angstroms on the PdOx. The SiC substrate (400 microns in thickness) was patterned with photoresist and a Schottky-diode photomask. A lift-off process completed the definition of the Schottky-diode pattern. The sensors were tested by measuring changes in forward currents at a bias potential of 1 V during exposure to H2 in N2 at temperatures ranging from 450 to 600 C for more than 750 hours. The sensors were found to be stable after a break-in time of nearly 200 hours. The sensors exhibited high sensitivity: sensor currents changed by factors ranging from 300 to 800 when the gas was changed from pure N2 to 0.5 percent H2 in N2
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