THE EVALUATION OF WAVE FORCES ON SEAWALLS

This Thesis is divided into two parts, Part A deals with the measurement and analysis of wave pressures on real seawalls and Part B deals with the resulting structural response of these seawalls. There have been only thirteen previous investigations to measure full scale wave impact pressures on coastal structures, and of these only five were conducted with sensitive electronic measuring equipment. The infrequent occurrence of impact pressures in a real sea has meant very little impact pressure data has been collected by these previous investigations. This investigation is the first of its kind to be carried out in the U.K. losing modern measuring, and recording equipment, the volume of wave impact data obtained (over 150 impacts recorded) is significantly greater than the combined results of all previous full scale investigations. The magnitude of the wave impacts measured during this investigation were generally lower than those measured by other investigations, the-maximum impact pressure being of the order of seven times the hydrostatic pressure. The pressures measured were found not to fit any current equations. The data has also shown that impact pressures can occur simultaneously over large areas and are not just localised events as previously thought. The most important parameter in the generation of wave impact pressures in a real sea was found to be the percentage of air entrained in the breaking wave. None of the equations currently in use for estimating wave impact pressures consider this parameter, which probably explains why these equations do not fit the measured data. An explicit equation for estimating the maximum impact pressure was not found but a method is given whereby -the impact pressure is related to local wave parameters including a coefficient based on the percentage air entrainment. Finite element modelling of the seawalls has shown that impact pressures can cause a significant dynamic response in the seawalls although short duration impacts (as measured in most model studies) have a negligible effect on response.Faculty of Technology; SWWA Exeter; CIRIA Londo

The Engineering Hubs and Spokes Project - institutional cooperation in educational design and delivery

The emergence of blended learning techniques that embrace a combination of face-to-face and online learning environments offers a raft of opportunity for flexibility in education. While much writing has focused on the opportunities for flexibility for the students and teachers, this paper focuses on the opportunities for effective sharing of expertise and effort between institutions. The Engineering 'Hubs and Spokes' project is a collaboration between The Australian National University and the University of South Australia. It draws on the strengths of each to improve the range and quality of educational opportunities for students. Two components of the project are underpinned by blended teaching and learning techniques: sharing of courses at the advanced undergraduate level; and development of an integrated graduate development program. We describe choices made, benefits identified, and the challenges encountered in the early stages of the project. We discuss recommendations for the future of cooperation in educational design and delivery, and comment on the opportunities that arise for structural reform of the higher education sector

Evaluating the Impact of a Quiz Question within an Educational Video

Educational videos are becoming more prevalent within a higher education context and the use of videos is now taken for granted. However, the full impact videos have on learning is under researched and not fully known. This study was conducted to investigate the effectiveness of quiz questions embedded throughout a video. Students from different modules (n1 = 102, n2 = 23) watched three different formats of videos and subsequent results of a multiple choice test were recorded and compared. In addition, viewing behaviour was recorded and explored to evaluate if this also impacted upon results. Results highlighted, that the performance on tests significantly improved after watching the video with embedded quiz questions throughout. Contrary to the test scores, students’ perceptions did not identify any differences, however students’ qualitative comments showed overwhelming support for quizzes embedded throughout a video. Implications on professional practice and further research to build upon this study are discussed

Lithium-Ion Small Cell Battery Shorting Study

Positive Temperature Coefficient (PTC) provides adequate sustained hard short protection for AEA batteries with up to 8 cells in series. PTC cannot protect against sustained hard short in AEA batteries with 10 cells or more in series. Protective fused connector is a proven way to protect larger batteries from hard short damage: a) Hard short not credible in unmanned missions; b) However, recommended during ground handling; c) Inexpensive item. Preliminary diode protection scheme has passed manned space safety requirements for high voltage batteries. SCM confirmed fused connector did not affect battery health, however, this affect of hard short on the its long calendar and cycle life performance needs to be verified

Tissue-specific host recognition by complement factor H is mediated by differential activities of its glycosaminoglycan-binding regions

Complement factor H (CFH) regulates complement activation in host tissues through its recognition of polyanions, which mediate CFH binding to host cell surfaces and extracellular matrix, promoting the deactivation of deposited C3b. These polyanions include heparan sulfate (HS), a glycosaminoglycan (GAG) with a highly diverse range of structures, for which two regions of CFH (referred to as CCP6-8 and CCP19-20) have been implicated in HS binding. Mutations/polymorphisms within these GAG-binding sites have been associated with age-related macular degeneration (AMD) and atypical hemolytic uremic syndrome (aHUS). Here we demonstrate that CFH has tissue-specific binding properties, mediated through its two HS-binding regions. Our data shows that the CCP6-8 region of CFH binds more strongly to heparin (a highly sulfated form of HS) than CCPs19-20 and that their sulfate specificities are different. Furthermore, the HS-binding site in CCPs6-8, which is affected by the AMD-associated Y402H polymorphism, plays the principle role in host tissue recognition in the human eye, whilst the CCP19-20 region makes the major contribution to the binding of CFH in the human kidney. This helps provide a biochemical explanation for the genetic basis of tissue-specific diseases such as AMD and aHUS, and leads to a better understanding of the pathogenic mechanisms for these diseases of complement dysregulation

Experimental and theoretical electron density analysis of copper pyrazine nitrate quasi-low-dimensional quantum magnets

The accurate electron density distribution and magnetic properties of two metal-organic polymeric magnets, the quasi-one-dimensional (1D) Cu(pyz)(NO3)2 and the quasi-two-dimensional (2D) [Cu(pyz)2(NO3)]NO3·H2O, have been investigated by high-resolution single-crystal X-ray diffraction and Density Functional Theory calculations on the whole periodic systems and on selected fragments. Topological analyses, based on Quantum Theory of Atoms in Molecules, enabled the characterization of possible magnetic exchange pathways and the establishment of relationships between the electron (charge and spin) densities and the exchange-coupling constants. In both compounds, the experimentally observed anti-ferromagnetic coupling can be quantitatively explained by the Cu-Cu super-exchange pathway mediated by the pyrazine bridging ligands, via a σ-type interaction. From topological analyses of experimental charge-density data, we show for the first time that the pyrazine tilt angle does not play a role in determining the strength of the magnetic interaction. Taken in combination with molecular orbital analysis and spin density calculations, we find a synergistic relationship between spin delocalization and spin polarization mechanisms and that both determine the bulk magnetic behavior of these Cu(II)-pyz coordination polymers

Assessment of bone marrow-derived Cellular Therapy in progressive Multiple Sclerosis (ACTiMuS):study protocol for a randomised controlled trial

BACKGROUND: We have recently completed an evaluation of the safety and feasibility of intravenous delivery of autologous bone marrow in patients with progressive multiple sclerosis (MS). The possibility of repair was suggested by improvement in the neurophysiological secondary outcome measure seen in all participants. The current study will examine the efficacy of intravenous delivery of autologous marrow in progressive MS. Laboratory studies performed in parallel with the clinical trial will further investigate the biology of bone marrow-derived stem cell infusion in MS, including mechanisms underlying repair. METHODS/DESIGN: A prospective, randomised, double-blind, placebo-controlled, stepped wedge design will be employed at a single centre (Bristol, UK). Eighty patients with progressive MS will be recruited; 60 will have secondary progressive disease (SPMS) but a subset (n = 20) will have primary progressive disease (PPMS). Participants will be randomised to either early or late (1 year) intravenous infusion of autologous, unfractionated bone marrow. The placebo intervention is infusion of autologous blood. The primary outcome measure is global evoked potential derived from multimodal evoked potentials. Secondary outcome measures include adverse event reporting, clinical (EDSS and MSFC) and self-assessment (MSIS-29) rating scales, optical coherence tomography (OCT) as well as brain and spine MRI. Participants will be followed up for a further year following the final intervention. Outcomes will be analysed on an intention-to-treat basis. DISCUSSION: Assessment of bone marrow-derived Cellular Therapy in progressive Multiple Sclerosis (ACTiMuS) is the first randomised, placebo-controlled trial of non-myeloablative autologous bone marrow-derived stem cell therapy in MS. It will determine whether bone marrow cell therapy can, as was suggested by the phase I safety study, improve conduction in multiple central nervous system pathways affected in progressive MS. Furthermore, laboratory studies performed in parallel with the clinical trial will inform our understanding of the cellular pharmacodynamics of bone marrow infusion in MS patients and the mechanisms underlying cell therapy. TRIAL REGISTRATION: ISRCTN27232902 Registration date 11/09/2012. NCT01815632 Registration date 19/03/201

Enhancing easy-plane anisotropy in bespoke Ni(II) quantum magnets

We examine the crystal structures and magnetic properties of several S = 1 Ni(II) coordination compounds, molecules and polymers, that include the bridging ligands HF2-, AF62- (A = Ti, Zr) and pyrazine or non-bridging ligands F-, SiF62-, glycine, H2O, 1-vinylimidazole, 4-methylpyrazole and 3-hydroxypyridine. Pseudo-octahedral NiN4F2, NiN4O2 or NiN4OF cores consist of equatorial Ni-N bonds that are equal to or slightly longer than the axial Ni-Lax bonds. By design, the zero-field splitting (D) is large in these systems and, in the presence of substantial exchange interactions (J), can be difficult to discriminate from magnetometry measurements on powder samples. Thus, we relied on pulsed-field magnetization in those cases and employed electron-spin resonance (ESR) to confirm D when J 0) and range from ≈ 8-25 K. This work reveals a linear correlation between the ratio d(Ni-Lax)/d(Ni-Neq) and D although the ligand spectrochemical properties may also be important. We assert that this relationship allows us to predict the type of magnetocrystalline anisotropy in tailored Ni(II) quantum magnets