Influence of structural distortions on the Ir magnetism in Ba2-xSrxYIrO6 double perovskites

We explore the relative strengths of spin orbit coupling and crystal field splitting in the Ir5+ compounds Ba2-xSrxYIrO6. In the case of strong spin orbit coupling and regular Ir5+ octahedra, one expects a nonmagnetic J = 0 state; in the case of distorted octahedra where crystal field effects dominate, the t2g manifold splits into a magnetic ground state. We report the results of continuously transitioning from the cubic Ba2YIrO6 double perovskite with ideal octahedra to the monoclinic Sr2YIrO6 double perovskite with distorted octahedra. We see no emergence of an enhanced Ir5+ magnetic moment in the series on increasing the structural distortions, as would have been the case for significant crystal field splitting. The near-constant magnetic moment observed through the Ba2-xSrxYIrO6 series reinforces the notion that spin-orbit coupling is the dominant force in determining the magnetism of iridium-oxygen octahedra in perovskite-like structure

Impact of hull propeller rudder interaction on ship powering assessment

It is the complex flow at the stern of a ship that controls the overall propulsive efficiency of the hull-propeller-rudder system. This work investigates the different analysis methodologies that can be applied for computing hull-propeller-rudder interaction. The sensitivity into which the interaction between the propeller and rudder downstream of a skeg is resolved as well as varying the length of the upstream skeg are also discussed including techniques to consider in such computations. Throughout the work, the importance of hull-propeller-rudder interaction for propulsive power enhancement is demonstrated. A final case study examines the performance of a twin skeg, twin screw arrangement

RANS computations of flow around a bulk carrier with energy saving device

The Fluid Structure Interactions group (University of Southampton) has been extensively involved in many research projects focusing on computations of ship wake field and the interactions between the propeller, rudder and the hull. A finite-volume RANS code, OpenFOAM (OpenFOAM, 2014) has been used mostly in majority of these works. The goal of the group has been to improve the in-house capability of prediction of ship stern flows using open-source software. In the present work OpenFOAM is benchmarked against a commercial code, Star-CCM+ (Star-CCM+, 2012), with the aim of exploring the differences in flow field results originating from particular features of both implementations.The Japan Bulk Carrier (JBC) has been chosen as a test case representative of the challenges faced in modern ship flow modelling. This vessel is fitted with an energy saving duct. The JBC case is part of the Tokyo 2015 CFD workshop and the latest in the series of benchmarking workshops to assess the state of art of marine CFD (Larsson et al., 2014). All computations are performed under steady state, fixed (even keel) conditions using identical grids and similar numerical setup. Presented analysis focuses on the mean flow, vortical structures and global hull forces

Overcoming barriers to the implementation of alternative fuels for road transport in Europe.

The success of implementing alternative fuels for road transport depends on their cost, performance and reliability. This paper focuses on the use of natural gas and LPG, hydrogen and biofuels in Europe. A brief presentation is given of their technical development status, their market potential, and barriers to their implementation in various market segments. Some market barriers are common to many new technologies, and can be overcome through adequate policy measures at European level. Generally, a combination of policies is required, and a number of supporting measures increase their effectiveness. The following policies affecting energy use in transport are discussed: market incentives, policies targeting technology and vehicle efficiency, and overall system improvement

Classical cornelia de lange syndrome

These two case reports illustrate the importance of doing a thorough dysmorphology examination for all so called “Multiple congenital anomalies” children and attempting to fit them into a recognizedsyndrome. Well over 2000 dysmorphic syndromes are now recognized and diagnosis of these children can be extremely difficult

Comparison of Alternative Methods for Estimating Household Trip Rates of Cross-Classification Cells with Inadequate Data

This paper investigates the forecast performance of a traditional cross-classification model and alternative models that seek to address the shortcomings of traditional cross-classification analysis, specifically when it has cells with inadequate data. The study uses five cross-sectional datasets collected in the San Francisco Bay Area in 1965, 1981, 1990, 1996, and 2000. Alternative models, estimated with travel data collected in the base year, were assessed for their ability to replicate the number of trips made by households in each cell of a cross-classification matrix and at the traffic zone level, respectively, in each of the five years. The results showed that the traditional crossclassification analysis (CCA) model, notwithstanding having a few unreliable cells provided more consistent predictions of travel than any of the alternative methods. They also show that it is better to synthesize trip rates for only those cells of the cross-classification matrix with inadequate data rather than to adjust the entire trip-rate matrix as is currently the practice

Structural Patterns in Asante Kente: An Indigenous Instructional Resource for Design Education in Textiles

Asante Kente is a richly coloured, intricately patterned indigenous hand woven fabric that is typically produced at Bonwire and Adanwomase in Ashanti Region, Ghana. Kente is woven in long narrow strips with brightly coloured silk or cotton yarns on Nsadua Kofi, the traditional narrow loom, which is a box-like wooden structure in which the weaver sits to weave. The strips are sewn together lengthways to purposely create definite patterns in the constructed cloth. Asante Kente motifs and cloth designs have names with philosophical meanings and colour symbolism that serve as a medium of communication to the indigenes.  The cloth designs consist of dots, lines, shapes, textures and colours that are carefully crafted to form geometric shapes and intricate patterns that exhibit balance, rhythm, variety, proportion and repetition. Unlike Asante Kente cloth designs that evolve on the loom, weaving in the higher education textiles curriculum requires expression of the structure of design concepts as drafts on point paper. To demystify drafting, which many textiles students perceive as “difficult to learn” led to adoption of the quasi-experimental approach to interpret selected Kente motifs to demonstrate the process of drafting to 148 Year One Industrial Art students of Kwame Nkrumah University of Science and Technology, Ghana. Using the draft as instructional resource, the students were guided to translate drafts they had made into woven Kente stole on the broadloom. The focus of this work was to bridge the gap between indigenous hand weaving and weaving as it is taught in the formal educational system. The structural patterns of Asante Kente designs provided the needed instructional resource and aesthetic experience to ensure successful learning of drafting in textiles design education. The importance of the study is to help preserve this natural cultural heritage of Kente weaving in the youth who are given formal education and again to set the pace for further research to be conducted into the use of motifs, symbols and designs in indigenous cloth as vast resource in design education in textiles. Keywords: Asante Kente Design, Structural Pattern, Instructional Resource, Drafting, and Textiles Design Educatio

Universal and Excavatable Controlled Low Strength Material Using High Loss on Ignition Fly Ash and Limestone Screenings†

Limestone screenings and high loss on ignition (LOI) fly ash are by-products that are stockpiling because of their unintentional production and the negative effects when utilized in portland cement concretes. The research objective was to investigate whether these by-products could produce controlled low strength materials (CLSMs) meeting the three types of Tennessee Department of Transportation (TDOT) 204.06 flowable fill specifications. TDOT defines these CLSMs as the following: general use, excavatable, and early strength. Each type is required to have an inverted slump flow of not less than 15 inches (38.1 cm) while meeting ASTM International D6024 at 24 hours. Because of trench unavailability, a 10-psi minimum compressive strength requirement was substituted for the ASTM D6024 ball drop. Early strength flowable fills must meet ASTM D6024 at 6 hours and provide a 30-psi minimum compressive strength at 24 hours. Excavatable flowable fills (EFFs) must also provide a 30-psi minimum at 28 days and a 140-psi maximum at 98 days. A universal flowable fill was produced without portland cement (PC), but by using an 11.1% LOI fly ash, class C fly ash, and limestone screenings. The EFF was produced using 92% high LOI fly ash and 7% PC by weight of the cementing materials. The results indicated that high LOI fly ash and limestone screenings can be combined to produce an excavatable CLSM satisfying TDOT CLSM requirements, and an universal CLSM can be produced that satisfies the requirements for general use, excavatable, and early strength TDOT CLSMs

Design and Production of Textile Mural: Combination of Computer Aided Programmes and Conventional Methods, An Alternative Innovative Approach

This novel textile mural production technique involves combination of digital printed fabric on flex sheet in conjunction with conventional appliqué and embroidery techniques. It was art-based studio research design that made use of exploration and experimental methods in the execution of four murals with different scenery. The works depict various activities within the Textiles section programme, Faculty of Art, College of Art and Built Environment, KNUST as a case study with the intent to promote and educate the populace. The activities were arranged into different scenery out of which four were selected for production. Step-by-step universal design methodology was carefully followed to ensure precision and easy reproduction of the murals. Flex sheet was used as substrate for the print out of the final works on which dyed, printed and woven fabrics were fixed to complete the sceneries. Wooden frames and transparent polyethylene rubber were used for the finishing of the works for them to be able to withstand harsh weather condition in order for them to be suitable for both out-door and in-door purposes. Background lighting system was installed within the frame to enhance their aesthetic appeal. This work was set to address the cumbersome, tedious, time consuming processes involve in conventional production of textile mural; cutting of pieces of textile materials and fixing them onto a substrate by applique and embroidery techniques. The importance of this alternative method is that it takes care of all the setbacks in the convention method as well as ensures precise and accurate reproduction of the work if need be. These were successful test projects that have set a new pace in design and production of textile mural. Combination of computer-aided design programmes like Adobe Photoshop CC and CorelDraw applications enable easy reproduction of textile murals in relatively shorter time with much precision and good finishing. Textile artists and interested researchers can now explore this new area of research for national development. Keywords: textile, mural, Adobe Photoshop CC, CorelDraw, flex sheet, appliqué, embroidery