Fluids trapped inside fluid inclusions in quartz from the multiphase Starav monzogranite in Etive, Argyll, were extracted under vacuum and quantitative data for H2O and CO2 were obtained manometrically. Na and K were determined on an aqueous leach from the decrepitated grains. A bivariate diagram of H2O/CO2 versus Na/K discriminates between magma pulses and mirrors the whole-rock trace-element chemistry. This work shows that compositional variations of fluids in quartz from a weakly mineralised granitoid intrusion are sensitive indicators of its magmatic history and identify subtle changes in its mineralogical composition.

The difficulty of monitoring growth parameters of climbing invasive plants subjected to different control options can be overcome by using standardized support structures (trellises). The utility of such support structures on aboveground biomass accumulation and fruit production was demonstrated using the invasive climber, bridal creeper in three invaded nature reserves near Perth in Western Australia. Mean above-ground plant biomass for plots provided with trellises ranged from 204 ± 38 g/m2 to 336 ± 31 g/m2, whereas it ranged from 66 ± 10 g/m2 to 118 ± 10 g/m2 in plots with no trellises. The mean number of fruits/m2 produced on shoots in plots provided with trellises ranged from 424 ± 159 to 3,787 ± 873 and was up to almost four orders of magnitude greater than the number of fruits produced on plants in plots with no trellis (ranging from 0 to 5.25 ± 7.9). The use of standardized trellises also showed that fruit volume and fruit seed number can vary significantly between sites. Standardized trellises have been installed at sites across Australia to assess the long-term impact of biological control agents introduced to manage bridal creeper.

At the centre of the Parkes 64—m radio telescope a region of diameter 17 m has recently been resurfaced to improve its efficiency at high frequencies. The first measurements using this section have been made at 22 GHz, in observations of both continuum sources and water tfapour masers. For these observations the receiver front-end used a mixer cooled in liquid nitrogen, followed by a 5 GHz cryogenic parametric amplifier as a second stage. The option of switching against an offset horn was available and the total systemnoise temperature was ∽ 750 K.

Epithelial cells lining the inner surface of the intestinal epithelium are in direct contact with a lumenal environment that varies dramatically with diet. It has long been suggested that the intestinal epithelium can sense the nutrient composition of lumenal contents. It is only recently that the nature of intestinal nutrient-sensing molecules and underlying mechanisms have been elucidated. There are a number of nutrient sensors expressed on the luminal membrane of endocrine cells that are activated by various dietary nutrients. We showed that the intestinal glucose sensor, T1R2+T1R3 and the G-protein, gustducin are expressed in endocrine cells. Eliminating sweet transduction in mice in vivo by deletion of either gustducin or T1R3 prevented dietary monosaccharide- and artificial sweetener-induced up-regulation of the Na+/glucose cotransporter, SGLT1 observed in wild-type mice. Transgenic mice, lacking gustducin or T1R3 had deficiencies in secretion of glucagon-like peptide 1 (GLP-1) and, glucose-dependent insulinotrophic peptide (GIP). Furthermore, they had an abnormal insulin profile and prolonged elevation of postprandial blood glucose in response to orally ingested carbohydrates. GIP and GLP-1 increase insulin secretion, while glucagon-like peptide 2 (GLP-2) modulates intestinal growth, blood flow and expression of SGLT1. The receptor for GLP-2 resides in enteric neurons and not in any surface epithelial cells, suggesting the involvement of the enteric nervous system in SGLT1 up-regulation. The accessibility of the glucose sensor and the important role that it plays in regulation of intestinal glucose absorption and glucose homeostasis makes it an attractive nutritional and therapeutic target for manipulation.

Equilibrium properties of linear theta-pinch plasmas are studied within the framework of the steady-state (∂ / ∂ t = 0) Vlasov– Maxwell equations. The analysis is carried out for an infinitely long plasma column aligned parallel to an externally applied axial magnetic field Bzext ê 2. Equilibrium properties are calculated for the class of rigid-rotor Vlasov equilibria, in which the jth component distribution function f j(H⊥, Pθ, υ 2) depends on perpendicular energy H⊥ and canonical angular momentum Pθ, exclusively through the linear combination H⊥ – ω jPθ, where ω j = const. = angular velocity of mean rotation. General equilibrium relations that pertain to the entire class of rigid-rotor Vlasov equilibria are discussed; and specific examples of sharp- and diffuse-boundary equilibrium configurations are considered. Rigid-rotor density and magnetic field profiles are compared with experimentally observed profiles. A general prescription is given for determining the functional dependence of the equilibrium distribution function on H⊥−ωjPθg in circumstances, where the density profile or magnetic field profile is specified.

We present a calculation of the hydrodynamic self-diffusion coefficient of a tagged particle in a dilute mono-dispersed suspension of small neutrally buoyant spheres undergoing a steady simple shearing motion. The displacement of the tagged particle parallel to the longitudinal or streamwise direction resulting from a ‘collision’ with one other particle is calculated on the assumption that inertia and Brownian motion effects are negligible. Summing over different pairs leads to a logarithmically divergent integral for the diffusivity which is rendered finite by allowing for the cutoff due to the occasional presence of another pair of particles. The longitudinal shearinduced self-diffusion coefficient is thus found to be 0.267a2γ{cln c−1 + O(c)], where γ denotes the applied shear rate, a is the radius of the spheres and c their volume concentration.

The analysis reported in Part 1 is extended here to the case in which the conductivity κ is large compared with the viscosity ν, the conduction ‘cut-off’ to the θ-spectrum then being at wave-number (ε/κ3)¼. It is shown, with a plausible and consistent hypothesis, that the convective supply of $\overline {\theta^2}$-stuff to Fourier components of θ with wave-numbers n in the range (ε/κ3)¼ [Lt] n [Gt] (ε/ν3)¼ is due primarily to motion on a length scale of order n-1 acting on a uniform gradient of θ of magnitude $[(\overline {\nabla \theta)^2}]^{\frac {1}{2}}$. The consequent form of the theta;-spectrum within this same wave-number range is$\Gamma (n) = \frac {1}{3}C \chi \epsilon ^{\frac {2}{3}} k^{-3}n^ {-\frac {17} {3}}.$

The way in which conduction influences (and restricts) the effect of convection on the distribution of θ at these wave-numbers beyond the conduction cut-off is discussed.

Pendeo-epitaxy of individual GaN and AlxGa12−xN films and single- and multi-layer heterostructures of these materials have been achieved on a columnar GaN seed layer using metallorganic vapor phase epitaxy. These structures have been characterized using scanning electron microscopy and atomic force microscopy. The RMS roughness value of the grown side wall plane (110) of these structures was 0.099 nm.

Pendeo-epitaxy of individual GaN and AlxGa,1-xN films and single- and multi-layer heterostructures of these materials have been achieved on a columnar GaN seed layer using metallorganic vapor phase epitaxy. These structures have been characterized using scanning electron microscopy and atomic force microscopy. The RMS roughness value of the grown side wall plane (1120) of these structures was 0.099 nm.

In this work, polycrystalline SiGe has been viewed as an alternative gate material to polysilicon in single wafer processing for the deep submicrometer VLSI applications. We studied deposition of the silicon-germanium (SiGe) films with different germanium concentrations (up to 85%) on SiO2 in a rapid thermal chemical vapor deposition reactor using GeH4 and SiH4/H2 gas mixture with the temperature ranging from 550°C to 625°C. Since the SiGe RTCVD process is selective toward oxide and does not form nucleation sites on the oxide easily, an in-situ polysilicon flash technique is used to provide the necessary nucleation sites for the deposition of SiGe films with high germanium content. It was observed that with the in-situ polysilicon flash as a pre-nucleation seed, the SiGe deposited on SiO2 forms a continuous polycrystalline layer. Polycrystalline SiGe films of about 2000Å in thickness have a columnar grain structure with a grain size of approximately 1000Å. Compositional analyses from Auger Electron Spectroscopy (AES) and Rutherford backscattering (RBS) show that the high germanium incorporation in the SiGe films has a weak dependence on the deposition temperature. It is also noted that the germanium content across the film thickness is fairly constant which is a critical factor for the application of SiGe films as the gate material. Lastly, we found that the surface morphology of SiGe films become smoother at lower deposition temperature.

In this paper, we report in-situ oxygen removal on Si using SiH2Cl2 and H2 in a high vacuum rapid thermal chemical vapor deposition reactor. The system consists of a main process chamber and a load-lock with base pressures of ∼ 1×10−7 Torr and 1×10−5 Torr respectively. The experiments were conducted in the temperature range of 750°C to 865 °C, and SiH2Cl2/H2 flow ratios of 1% to 7%. For comparison, samples were also prepared with only H2 prebaking in the same temperature and pressure range as well as with no in-situ cleaning. With no in-situ cleaning, the oxygen content was found to decrease at higher temperatures suggesting partial oxygen removal during early stages of growth. The results indicate a strong temperature dependence for the H2 clean with an increased effectiveness at higher temperatures which is believed to be due to temperature dependence of oxygen desorption from Si. In the temperature range studied, the SiH2Cl2 clean was found to be effective at 750°C. An additional oxygen removal mechanism appears to be introduced by the addition of SiH2Cl2. Using this approach, at 750°C, the peak oxygen concentration can be reduced to 4×1018 cm−3 whereas the H2 anneal at the same temperature results in a concentration of 6×1018 cm−3. At higher temperatures, the oxide can be removed in pure H2 just as efficiently or desorbed during initial stages of growth. The results show that the efficiency of the process increases as more SiH2 Cl2 is added to the system up to a critical pressure. However, if the SiH2Cl2 partial pressure is above this critical value, Si deposition can occur on the Si surface yielding an optimum partial pressure which is a function of temperature. The results indicate that the use of a small amount of SiH2Cl2 as a cleaning agent may provide a low temperature pre-epi clean.

Low pressure chemical vapor deposition of polysilicon in a lamp heated rapid thermal processor (RTCVD) has been studied. Polysilicon films were deposited using SiH4 diluted in Ar. Structural characterization of the films was accomplished by transmissionelectron microscopy (TEM), scanning tunneling microscopy (STM), secondary ion mass spectroscopy (SIMS), auger electron spectroscopy (AES) and ultraviolet surface reflectance measurements. Smooth polysilicon films were obtained at deposition temperatures above 700ºC with rms roughness values better than 100 Å. Both p- and n- polysilicon gated MOS capacitors were fabricated using 80 - 200 Å thick gate oxides grown by dry oxidation in a conventional furnace. Polysilicon doping was achieved by ion-implantation and rapid thermal annealing (RTA). Our results show that the electrical properties ofthe capacitors fabricated using RTCVD polysilicon are comparable to those of conventional polysilicon. Dopant diffusion through the gate is a problem for both types of polysilicon and can lead to a degradation of the electrical properties.

Selective depositions of germanium thin films have been investigated in a cold-wall, lamp heated rapid thermal processor. Films were deposited at low pressures (1 Torr-8 Torr) using the thermal decomposition of germane. Selectivity was maintained throughout the temperature range investigated, 350°C-600°C. Growth rates as high as 800 Å/min were obtained at 425°C where deposition is controlled by the surface reactions, making germanium compatible with the throughput requirements of single wafer manufacturing. Three dimensional growth was seen at temperatures above 450°C resulting in a rough surface morphology. Smooth films were deposited below 450°C with the films characterized by two dimensional growth. In this work, germanium is considered as a potential material to fabricate MOS transistors with raised source and drain junctions (UPMOS). Kelvin structures were fabricated to study the effect of the intermediate germanium layer between aluminum and silicon on contact resistance. It is shown that contact resistivity is improved by approximately 17% using an Al/p-Ge/p+-Si structure. In this work, it is also shown that titanium germanide formation can be used as a means of reducing the resistivity of the Ge buffer layer.

VLBI observations of the nucleus of Centaurus A were made in April, 1982 at two frequencies with an array of five Australian radio antennas as part of the Southern Hemisphere VLBI Experiment (SHEVE). Observations were undertaken at 2.29 GHz with all five antennas, while only two were operational at 8.42 GHz. The 2.29 GHz data yielded significant information on the structure of the nuclear jet. At 8.42 GHz a compact unresolved core was detected as well.

Six radio telescopes were operated as the first southern hemisphere VLBI array in April and May 1982. Observations were made at 2.3 and 8.4 Ghz. This array produced VLBI images of 28 southern hemisphere radio sources, high accuracy VLBI geodesy between southern hemisphere sites, and subarcsecond radio astrometry of celestial sources south of declination −45 degrees. This paper discusses only the astrophysical aspects of the experiment.

This note outlines the principal results of an exhaustive study of Industrialisation and the Basis for Trade which will be published by Cambridge University Press later this year.

The observed width of spectral features in CP 0328, CP 0834, and CP 1919 are approxmately proportional to the fourth power of frequency, thus supporting the hypothesis that the slow spectral variations of these pulsars are due to interstellar scintillation. The spectral features in CP 0834, CP 1133, and CP 1919 are observed to drift systematically at rates compatible with a simple interstellar scintillation model. Pulsar velocities of ~ 100 km sec-1 are inferred from these spectral drift rates.