5,787 research outputs found
Current Development of Carbon Capture and Storage in the UK – a Non Technical Review
This paper reviewed a current situation of carbon capture and storage (CCS) development in the UK mainly within the last 10 years in general. It looked at the positive ways to implement the CCS technologies, including the geological advantages, potential sector growth, financial incentives, and the support in the policies. Current projects were brought forward together with the university and industry research. Some concerns and limitation of applying CCS technologies were discussed. To the end, the conclusion was made that the UK is in a good position to implement CCS technologies and would become a global leader in CCS development providing that the first four trials were successful
Pulse and canola frost identification:the back pocket guide
This field guide will help you identify the common symptoms of frost damage in pulse and canola crops. It also contains pictures of other plant symptoms often confused with frost damage in these crops.
Frost damage reduces crop yield and grain quality. Early identification of symptoms allows timely crop salvage decisions to be made.
Inspect pulse and canola crops between bud formation and during pod growth if right air temperature (recorded 1.2 m above ground) falls below 2 degrees celsius and there was a frost.
Check low lying, light coloured soil types and known frost prone areas first. Then check other areas.https://researchlibrary.agric.wa.gov.au/bulletins/1139/thumbnail.jp
Benchmarking, development and applications of an open source DSMC solver
Several important engineering gas flow problems fall within the transition Knudsen number regime, e.g. re-entry of spacecraft, or gas flows in micro-scale geometries. The transition regime remains the most difficult to obtain reliable analytical or numerical results for, but the most successful method has been the direct simulation Monte Carlo (DSMC) numerical technique. Due to the nature of high temperature, hypersonic flows, and equipment limitations at the micro-scale, there is a scarcity of reliable experimental data for transition regime flows; numerical experiments using DSMC are an essential tool for the design of engineering systems that encounter these kinds of flows. We benchmark a recently developed open-source DSMC solver against existing DSMC solvers, analytical solutions, and experimental data. The solver is then extended to include some important features that enable it to be applied to a larger range of engineering problems. Vibrational energy and the quantum-kinetic chemical reaction model are implemented in our DSMC solver, preparing it for use with hypersonic flow problems with shockwaves and local regions of very high temperature. Low speed fixed pressure boundary conditions are also implemented, for use with simulations of gas flows in micro-channels. The extended solver is then used to investigate two different engineering problems. Firstly, simulations of gas flows in micro-channels with bends are performed. We find that the inclusion of a sharp ninety degree bend does not lead to significant losses, and can even lead to a small increase in mass flow rate within a limited range of Knudsen number. Adding a second bend is found to increase this mass flow rate enhancement. Finally, we investigate rarefied gas effects on high area-to-mass ratio spacecraft in low Earth orbit, taking inspiration from the Crookes radiometer. We find that the ii non-equilibrium gas effects can be exploited for use as propellant-free inter-spacecraft position control within a swarm, by altering the temperature of one spacecraft relative to another. A small degree of attitude control can be exercised in a similar manner, through non-uniform heating of an individual spacecraft.Several important engineering gas flow problems fall within the transition Knudsen number regime, e.g. re-entry of spacecraft, or gas flows in micro-scale geometries. The transition regime remains the most difficult to obtain reliable analytical or numerical results for, but the most successful method has been the direct simulation Monte Carlo (DSMC) numerical technique. Due to the nature of high temperature, hypersonic flows, and equipment limitations at the micro-scale, there is a scarcity of reliable experimental data for transition regime flows; numerical experiments using DSMC are an essential tool for the design of engineering systems that encounter these kinds of flows. We benchmark a recently developed open-source DSMC solver against existing DSMC solvers, analytical solutions, and experimental data. The solver is then extended to include some important features that enable it to be applied to a larger range of engineering problems. Vibrational energy and the quantum-kinetic chemical reaction model are implemented in our DSMC solver, preparing it for use with hypersonic flow problems with shockwaves and local regions of very high temperature. Low speed fixed pressure boundary conditions are also implemented, for use with simulations of gas flows in micro-channels. The extended solver is then used to investigate two different engineering problems. Firstly, simulations of gas flows in micro-channels with bends are performed. We find that the inclusion of a sharp ninety degree bend does not lead to significant losses, and can even lead to a small increase in mass flow rate within a limited range of Knudsen number. Adding a second bend is found to increase this mass flow rate enhancement. Finally, we investigate rarefied gas effects on high area-to-mass ratio spacecraft in low Earth orbit, taking inspiration from the Crookes radiometer. We find that the ii non-equilibrium gas effects can be exploited for use as propellant-free inter-spacecraft position control within a swarm, by altering the temperature of one spacecraft relative to another. A small degree of attitude control can be exercised in a similar manner, through non-uniform heating of an individual spacecraft
Accounting for the dispersion in the x ray properties of early-type galaxies
The x ray luminosities of early-type galaxies are correlated with their optical (e.g., blue) luminosities (L sub X approx. L sub B exp 1.6), but the x ray luminosities exhibit considerable scatter for a given optical luminosity L sub B. This dispersion in x ray luminosity is much greater than the dispersion of other properties of early-type galaxies (for a given L sub B), such as luminosity scale-length, velocity dispersion, color, and metallicity. Here, researchers consider several possible sources for the dispersion in x ray luminosity. Some of the scatter in x ray luminosity may result from stellar population variations between galaxies with similar L sub B. Since the x ray emitting gas is from accumulated stellar mass loss, the L sub X dispersion may be due to variations in integrated stellar mass loss rates. Another possible cause of the L sub X dispersion may be variations in the amount of cool material in the galaxies; cool gas may act as an energy sink for the hot gas. Infrared emission may be used to trace such cool material, so researchers look for a correlation between the infrared emission and the x ray emission of early-type galaxies at fixed L sub B. Velocity dispersion variations between galaxies of similar L sub B may also contribute to the L sub X dispersion. The most likely a priori source of the dispersion in L sub X is probably the varying amount of ram-pressure stripping in a range of galaxy environments. The hot gaseous halos of early-type galaxies can be stripped in encounters with other galaxies or with ambient cluster gas if the intracluster gas is sufficiently dense. Researchers find that the most likely cause of dispersion in the x ray properties of early type galaxies is probably the ram-pressure stripping of gaseous halos from galaxies. For a sample of 81 early-type galaxies with x ray luminosities or upper limits derived from Einstein Observatory observations (CFT) researchers calculated the cumulative distribution of angular distances between the x ray sample members and bright galaxies from the Revised Shapley - Ames catalog. Collectively, galaxies with low x ray luminosities (for a given L sub B) tend to be in denser environments than galaxies with higher x ray luminosities
Rarefied gas effects on the aerodynamics of high area-to-mass ratio spacecraft in orbit
The aerodynamic situation of a satellite-on-a-chip operating in low Earth orbit bears some resemblance to a classical Crookes radiometer. The large area-to-mass ratio characteristic of a SpaceChip means that very small surface-dependent forces produce non-negligible accelerations that can significantly alter its orbit. When the temperature of a SpaceChip changes, the drag force can be changed: if the temperature increases, the drag increases (and vice versa). Analytical expressions available in the literature that describe the change in drag coefficient with orbit altitude and SpaceChip temperature compare well with our direct simulation Monte Carlo results presented here. It is demonstrated that modifying the temperature of a SpaceChip could be used for relative orbit control of individual SpaceChips in a swarm, with a maximum change in position per orbit of 50 m being achievable at 600 km altitude
Langmuir-Maxwell and Langmuir-Smoluchowski boundary conditions for thermal gas flow simulations in hypersonic aerodynamics
The simulation of nonequilibrium thermal gas flow is important for the aerothermodynamic design of re-entry and other high-altitude vehicles. In computational fluid dynamics, the accuracy of the solution to the Navier–Stokes–Fourier (N–S–F) equations depends on the accuracy of the surface boundary conditions. We propose new boundary conditions (called the Langmuir–Maxwell and the Langmuir–Smoluchowski conditions), for use with the N–S–F equations, which combine the Langmuir surface adsorption isotherm with the Maxwell/Smoluchowski slip/jump conditions in order to capture some of the physical processes involved in gas flow over a surface. These new conditions are validated for flat plate flow, circular cylinder in cross-flow, and the flow over a sharp wedge for Mach numbers ranging from 6 to 24, and for argon and nitrogen as the working gases. Our simulation results show that the new boundary conditions give better predictions for the surface pressures, compared with published experimental and DSMC data
Fusing fact and fiction: biography and autobiography in the novels of Virginia Woolf
Virginia Woolf was noted for a preoccupation with the genre of life-writing throughout her career. Her aims when it came to reshaping the nature of biographical and autobiographical literature were numerous. She veered away from the aggrandising and patriarchal methods with which Victorian biographers tended to depict their subjects. She increased the focus on women in life-writing, examining and subverting traditionally prescribed gender roles prevalent in both her society and the literature that reflected it, and advocating a balance between male and female patterns of thinking. She also devised a method of incorporating both basic biographical fact and aspects of fiction into life-writing in order to approach a more truthful depiction of a subject’s personality or character. This method is linked to the aforementioned balance of gendered thought patterns, since Woolf often aligns factuality with male thinking and the contrasting qualities of fiction, such as intuition, ambivalence and perspicacity, with female thinking. This thesis examines three novels which demonstrate Woolf’s constant preoccupation with combining fact and fiction in order to capture the essence of personality. In her debut novel, The Voyage Out, she presents Rachel Vinrace, who must achieve a balance of male-oriented fact with female-oriented insight in order to fashion a sufficient identity for herself and to identify others in a selective and judicious manner, thus being simultaneously autobiographical and biographical. In Orlando, Woolf explicitly subverts the traditional Victorian biography by depicting Vita Sackville-West as a man who transforms into a woman and remains living for over 400 years. In presenting such a character, Woolf posits that personality consists of and is influenced by myriad aspects of a person’s life that cannot be documented in the restrictive manner employed by Victorian biographers. Orlando’s essence being obfuscated by manifold “selves” attests to Woolf problematizing attempts to attain such an essence. The same challenge is particularly important in her autobiographical novel, To the Lighthouse, in which she transposes the traumas of her own life into a fictitious narrative in order to achieve catharsis for her and her readers, and to present the difficulty in capturing the essence of character. The conclusion that Woolf eventually posits is that personality cannot be reduced to an essence, but rather that it consists of idiosyncrasies that are various, intertwining, and capricious
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