Multiscale models of colloidal dispersion of particles in nematic liquid crystals

We use homogenization theory to develop a multiscale model of colloidal dispersion of particles in nematic liquid crystals under weak-anchoring conditions. We validate the model by comparing it with simulations by using the Landau–de Gennes free energy and show that the agreement is excellent. We then use the multiscale model to study the effect that particle anisotropy has on the liquid crystal: spherically symmetric particles always reduce the effective elastic constant. Asymmetric particles introduce an effective alignment field that can increase the Fredericks threshold and decrease the switch-off time

Father inclusive practice in a parenting and early childhood organisation: The development and analysis of a staff survey

Aim: The successful embedding of father inclusive practice (FIP) in parenting and early childhood organisations is relatively new and therefore challenging to assess. The purpose of this study was to describe the process of adapting an existing tool, the Knowledge about fatherhood checklist (KAFC), to suit the parenting service context and apply the modified survey to establish a baseline of attitudes and practice of all staff at an established parenting and early childhood service in Western Australia, Ngala. Method: Following the application of the KAFC at Ngala in 2016, feedback provided by the staff led to a reflective and iterative process of review to adapt the KAFC. In 2018, all staff were asked to complete the adapted survey – the 23-item Father inclusive practice survey (FIP survey) – in order to assess the attitudes and behaviours of everyone in the organisation. The FIP survey covers aspects of competency as well as knowledge and attitudes in relation to fatherhood or father engagement. Results: Results indicated generally high levels of appreciation of the fathering role by Ngala staff. However, a number of areas for improvement in staff knowledge and attitudes were identified, including the benefit of reflecting on personal experiences of fathering, the awareness of the gendered stereotyped view of men, and the importance of the influence fathers can make in the context of attachment and breastfeeding. Conclusions: The implementation of this FIP survey informs improvements to staff orientation and training in FIP, and provides insights into staff attitudes, beliefs and practice regarding acknowledgement of the important contribution fathers make to the development and wellbeing of their children

Assessing the influence of the rhizosphere on soil hydraulic properties using X-ray Computed Tomography and numerical modelling

Understanding the dynamics of water distribution in soil is crucial for enhancing our knowledge of managing soil and water resources. The application of X-ray Computed Tomography (CT) to the plant and soil sciences is now well established. However, few studies have utilised the technique for visualising water in soil pore spaces. Here we utilise this method to visualise the water in soil in situ and in three-dimensions at successive reductive matric potentials in bulk and rhizosphere soil. The measurements are combined with numerical modelling to determine the unsaturated hydraulic conductivity, providing a complete picture of the hydraulic properties of the soil. The technique was performed on soil cores that were sampled adjacent to established roots (rhizosphere soil) and from soil that had not been influenced by roots (bulk soil). A water release curve was obtained for the different soil types using measurements of their pore geometries derived from CT imaging and verified using conventional methods e.g. pressure plates. The water, soil and air phases from the images were segmented and quantified using image analysis. The water release characteristics obtained for the contrasting soils showed clear differences in hydraulic properties between rhizosphere and bulk soil, especially in clay soil. The data suggests that soils influenced by roots (rhizosphere soil) are less porous due to increased aggregation when compared to bulk soil. The information and insights obtained on the hydraulic properties of rhizosphere and bulk soil will enhance our understanding of rhizosphere biophysics and improve current water uptake models

Getting Started: Using a Global Circumnavigation Balloon Flight to Explore Picosatellite (CubeSat) Technology

Washington University\u27s Project Aria is currently involved in the CubeSat program. Project Aria is a student-led engineering education, research, and K-12 outreach program. The project’s CubeSat goal is the development of a spherical imaging spacecraft, the Palantir , ready for launch in late 2002. Recently, the Palantir team was offered the opportunity to fly a small payload on a global circumnavigation balloon flight in mid-2001. The payload would collect atmospheric data such as temperature, pressure, and humidity. The student team decided to use this opportunity to explore various technologies they plan for Palantir. This resulting in a fast, challenging engineering project that developed the skills needed for a successful picosatellite project. The technologies to be explored include a self-contained power system with solar cells, on-board computers, on-board cameras, various sensors, satellite communications, and mission operations. One specific test involves mounting temperature sensors throughout the probe. The students will then compare actual thermal reading to predicted thermal readings. Other specific tests will involve the use of several different types of solar cells to judge performance. Finally, students will remotely operate the payload as they would the satellite to explore operating concepts and tools. This balloon opportunity allows students the chance to explore various technologies and operating concepts needed for a successful satellite program without the high cost of a launch. This paper briefly describes the Palantir CubeSat program, the Palantir Technology Demonstration balloon program, and the results of the flight. Particular attention is paid to goals of the balloon flight and a review of the successes and failures. Lessons learned from the test flight can be applied to other universities seeking to develop CubeSats and other project-based programs

Money in the Production Function: An Alternative Test Procedure

This paper discusses and applies an alternative test procedure to the debate regarding the inclusion of real money balances in the neoclassical production function. The alternative test procedure involves the development of a counterexample of the model of a theory being tested and simultaneously testing the model and its counterexample using the same testing conventions and procedures. The results obtained by using the test procedure cast doubt on the practice of including real money balances in the neoclassical production function.

Ultra-short carbon nanotubes as nanocapsules for medical imaging and therapy

This thesis details the development of ultra-short, single-walled carbon nanotubes (US-tubes) for use as nanocapsules to contain and deliver medical agents for both imaging (Gd3+ ) and therapeutic (211 At) purposes. In particular, Gd3+ -loaded US-tubes, known as gadonanotubes, operate as high-performance MRI contrast agents with relaxivities (image enhancement efficacy) a factor of 40-100 greater than current clinical contrast agents. Furthermore, gadonanotube relaxivities are highly pH-dependent, with image intensity nearly tripling from pH 7.5 to 6.8. Coupled with their high efficacies and targeting potential, these agents are promising candidates for next-generation targeted imaging probes for the early detection of cancer. Single gadonanotubes have also been encapsulated in a polymer shell for use as an intravenous MRI contrast agent. In addition, a new functionalization scheme has been developed to covalently attach a variety of amino acids in high quantity to the outer surface of the gadonanotubes and to attach a small peptide sequence for targeting breast cancer cells. The gadonanotubes have also been used as magnetic cell labeling agents, while also demonstrating efficacy in vivo as contrast agents. In addition to functioning as an imaging agent platform, the US-tubes have demonstrated efficacy as nanocapsules for radiotherapeutic agents. Astatine-211 (At-211), an α-emitting radionuclide, can be loaded inside the US-tube with excellent containment stability for the targeted delivery of an α-radiotherapeutic agent to micrometastatic and single-cell cancers. The loading levels for At-211 are comparable to, or better than, other known compounds. At-211, existing as the mixed-halogen compound 211 AtCl, is retained in the US-tube nanocapsules due to van der Waals forces between the 211AtCl and the interior sidewalls of the nanotube. Finally, the US-tubes have been shown to induce few health risks in mammalian experiments. Acute toxicity tests were conducted on mice with both raw and purified full-length carbon nanotubes (SWNTs), as well as US-tubes, using large doses (up to 1 g/kg of bodyweight). Even at these large doses, no animal death was recorded, although in a few cases behavioral changes were observed. Nanotubes were observed to be eliminated from the liver and kidneys through the urine and feces. It is believed that any toxicity at high doses can be attenuated (and prevented) by properly formulating the administered dose

World-views and the world : a study of the role of linguistic frameworks in our knowledge of the real

This work is a contribution to the debate between realism and relativism in metaphysics. Realism is the thesis that there is a unique real world which exists independently of our perceiving it and thinking about it. Furthermore, realism has it that the nature of the unique real world is as it is independently of how we perceive it to be, and of how our theories describe it. According to realism, to give a correct account of some constituent of the world, or of the world itself, is to present a God's Eye View of that constituent, or the world. There can only be one complete and correct account of the real world. The realist standpoint may also be referred to as the standpoint of objectivity, or as the externalist perspective