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Summary The Mid-Norwegian segment of the Norwegian Continental Shelf, between 62° and 67° N, includes a Berriasian to Paleocene basin fill of >12.5 km thickness. The area of deposition covers several major basins and sub-basins, including the More and Voring basins and adjacent terraces. Although the area contains the large Ormen Lange and Aasta Hansteen gas fields, the discovery density in post-Jurassic strata is not comparable with the Jurassic petroleum play on the Halten-/Donna terraces. To fully re-assess the Cretaceous petroleum system of the Norwegian Sea, an integrated petroleum system analysis study was performed including i) source rock evaluation, ii) top-down petroleum systems analysis, iii) petroleum systems modeling and iv) migration and charge analysis. Three rich source rock formations have been proven, indications for five additional source rock formations related to Cretaceous OAE collected. Regional petroleum-source correlations identified the presence of oils and condensates of pre-Albian, Cenomanian/Turonian and post-Turonian origin. The study shows that the volumes of expelled hydrocarbons and thus the YTF oil volumes are underestimated in the area. The Cretaceous petroleum systems study results were finally implemented in recent exploration strategies and proven by new discoveries on the Norwegian Continetal Shelf.

The passivation properties of the Si GaAs(110) interface have been studied using scanning tunnelling microscopy/spectroscopy (STM/STS) and soft X-ray photoemission spectroscopy (SXPS). Silicon has been deposited at room temperature and STM images show the sub-monolayer growth of silicon islands on the GaAs substrate. The electrical properties of these islands together with the clean surface have been investigated using scanning tunnelling spectroscopy (STS). The spectroscopy clearly illustrates the difference in electrical properties between atomically flat regions of GaAs as compared to those containing defects or steps, i.e. where surface band bending occurs. We have investigated the use of sub-monolayer Si coverages to modify the electronic structure of the surface. Height variations of 3–4Aacross Si islands and 2Aacross steps on the GaAs surface have also been observed using the STM. STS spectra, collected simultaneously with the STM image, showed the Si to have semiconducting properties differing from that of crystalline Si and the GaAs substrate. Comparisons between the STM and STS results together with SXPS have provided a correlation between the structural, electrical and chemical nature of the Si/GaAs(110) interface.

Previous current–voltage studies of In contacts deposited on atomically clean (intimate) In53Ga47As(100) have indicated the potential to “select” barrier heights in this materials system by cryogenic processing. Soft x-ray photoemission spectroscopy was used to determine the electronic and chemical nature of these interfaces, as a function of formation temperature. Metallization at room temperature results in a predominantly three-dimensional mode of growth, accompanied by the outdiffusion of As. Low temperature metallization appears to reduce clustering and inhibit As outdiffusion. It is proposed that the distribution of surface states and the fermi level pinning position are altered by the changes that occur in the geometry and bonding of the interface at low temperature.

One challenge in the processing of In 53 Ga 47 As/InP(100) heterostructures is the enhancement of the low Schottky barrier heights (Φ b ) typically exhibited by metal-nIn 53 Ga 47 As(100) contacts. Previous studies of the metallisation of chemically etched In 53 Ga 47 As surfaces have reported increases in Φ b if metallisation is performed at 77 K. This study extends this concept to probe the idealised case of the formation of metal contacts (Au-, Cu- and In-) to atomically clean nIn 53 Ga 47 As/InP(/I) at 80 K and room temperature (294 K). The in-situ current-voltage measurements of intimate Au and Cu contacts formed at both temperatures exhibited ohmic characteristics. However, intimate In contacts formed at 80 and 294 K showed diodic behaviour (Φ b 0.45 and 0.30 eV, respectively), with an improvement in the rectification when formed at 80 K. Conversely, In contacts to etched surfaces were ohmic. It is proposed that this behaviour is linked to the alteration of the structure and nature of the interface as a result of the various fabrication techniques. These results indicate the potential to select Φ b on In 53 Ga 47 As via a combination of cryogenic processing and surface preparation.

Carbon dioxide injection into an extrusion cooker is able to produce structured extrudates under low-temperature and high-moisture conditions when the release of steam does not contribute. The effect of carbon dioxide injection pressure on the extruder response and the resulting extrudate structure was studied for wheat starch-sucrose mixtures. An increase in gas pressure decreased the pressure gradient in the extruder and the die pressure, although it had a relatively small effect on the specific mechanical energy consumption. The degree of expansion reached a maximum (and the density a minimum) with increasing gas injection pressure for each composition for the extrusion conditions studied.

Five herbicides commonly used for suppression of weed growth in white clover seed crops were tested for toxicity to white clover ( Trifolium repens ), the nodule-forming bacteria Rhizobium trifolii , and the nitrogen-fixing symbiosis of these organisms. Trials were carried out under bacteriologically-controlled and glasshouse conditions. Overall, paraquat was more toxic to R. trifolii growth than MCPB, followed by bentazone, fusilade and kerb as the least toxic. Bentazone showed the least toxicity to plant growth, nodulation and N 2 fixation under bacteriologically-controlled conditions. All the other herbicides inhibited C 2 H 2 reduction, while nodule number and plant fresh weight were lowered by paraquat. MCPB and kerb. However, when plants grown in soil were treated, kerb showed the least toxicity with fusilade, bentazone and MCPB being intermediate in toxicity. This study also showed that changes in growth medium, nitrogen status and soil moisture content can alter the activity of particular herbicides. Possible toxicity of herbicides to plant growth and N 2 fixation should be considered when using herbicides to control weeds in leguminous crops.

We have established a sub-clone of the murine hybridoma C1E3, termed C1E3.10. This sub-clone was derived by adaptation to the serum-free/defined medium Excell 300 (1), followed by recloning for high antibody secretion. Production of monoclonal antibody in stationary flask cultures gave similar results in both serum containing and EXCELL 300 medium. Using this cell line we have monitored the production of monoclonal antibody in EXCELL 300 over an extended period of culture, greater than 75 days, in a small scale cell entrapment bioreactor, (Dynacell). The levels of glucose, lactic acid and glutamine in the reservoir of the bioreactor were monitored and analysed. Variations in concentration of lactic acid, in particular, had a profound effect on the rate of antibody production.

The adrenocortical tissue which regenerates after adrenal enucleation, and contralateral uninephrectomy and adrenalectomy, resembles histologically zona fasciculata tissue which normally synthesises glucocorticoids. However, increases in blood pressure after enucleation (adrenal regeneration hypertension – ARH) were preceded by a rise in exchangeable body sodium similar to that found with mineralocorticoid-induced hypertension (e.g. DOC/salt rat model). Glucocorticoid involvement in ARH rats was tested, firstly by infusing dexamethasone into control and ARH rats to see whether ACTH suppression would lower blood pressure by reducing adrenocortical activity and, secondly, by infusing dexamethasone into rats with intact adrenals to see whether conditions for ARH (i.e. uninephrectomy and/or saline consumption) pre-disposed rats to the hypertensinogenic properties of glucocorticoids. Low-dose dexamethasone infusions (10 μg/day for 5 days) in ARH rats did not affect blood pressure but in control animals caused a significant (P < 0.01) increase from 128 ± 3 to 151 ± 5 mmHg. Corticosterone, 18-hydroxycorticosterone and deoxycorticosterone plasma concentrations were suppressed in both groups by dexamethasone treatment; plasma renin concentrations were lower in ARH rats than in controls. Uninephrectomy or 1% NaCl as drinking fluid did not affect the blood pressure rise induced by sc infusion of 10 μg dexamethasone/day for 14 days in rats with intact adrenals. The temporal relationship between blood pressure changes and exchangeable body sodium in ARH rats resembles that in mineralocorticoid-induced hypertension. Glucocorticoid, unlike mineralocorticoid, induced hypertension is not affected by a reduction in renal mass or increased sodium intake.