Use of additive manufacture and Stirling Engines as engineering education tools

The recent proliferation of low to medium cost additive manufacturing equipment opens a doorway to using the technology for aiding the education of many engineering principles. Stirling cycle engines are highly complex thermodynamic machines that, if delved into, demonstrate many mechanical engineering disciplines. Importantly fully functional engines, using safe hot and cold water as the energy source, can be made by polymer additive manufacture using commonly available materials and printing machines. This process somewhat negates the need to invest in high cost laboratory demonstration equipment. It also allows remote and poorly funded institutions or individuals to work with live equipment. This publication will demonstrate the use of additive manufactured Stirling Engines for effective teaching in creative design, optimization product development, thermodynamics, mechanics, computational fluid dynamics, finite element analysis, live data acquisition, material science and additive manufacture

Report on final workshop on globalisation and seafood trade legislation: the effect on poverty in India. 23-24 January 2003, Visakhapatnam, Andhra Pradesh, India (NRI report no. 2721)

This report presents the proceedings and findings of a workshop held in the Green Park Hotel, Visakhapatnam from 23 to 24 January 2003. It was attended by participants (36 in all) representing a cross section of the fisheries industry from producer organisations, NGOs, government organisations and private companies involved in the fish export industry of India. (See appendix 1 ). The report outlines the results of the research project on "Globalisation and Seafood Trade Legislation – The Impact on Poverty in India" funded by the Post Harvest Fisheries Research Programme (PHFRP) of the Department for International Development (DFID). The workshop considered the status of the export industry in Kerala, Orissa and Andhra Pradesh and the effect that export legislation is having on livelihoods of the poor in these three states. The discussion of the issues raised is given in the main body of the report (section 2) with summaries of the presentations in the Appendices 3- 5

Fate specification and tissue-specific cell cycle control of the <i>Caenorhabditis elegans</i> intestine

Coordination between cell fate specification and cell cycle control in multicellular organisms is essential to regulate cell numbers in tissues and organs during development, and its failure may lead to oncogenesis. In mammalian cells, as part of a general cell cycle checkpoint mechanism, the F-box protein β-transducin repeat-containing protein (β-TrCP) and the Skp1/Cul1/F-box complex control the periodic cell cycle fluctuations in abundance of the CDC25A and B phosphatases. Here, we find that the Caenorhabditis elegans β-TrCP orthologue LIN-23 regulates a progressive decline of CDC-25.1 abundance over several embryonic cell cycles and specifies cell number of one tissue, the embryonic intestine. The negative regulation of CDC-25.1 abundance by LIN-23 may be developmentally controlled because CDC-25.1 accumulates over time within the developing germline, where LIN-23 is also present. Concurrent with the destabilization of CDC-25.1, LIN-23 displays a spatially dynamic behavior in the embryo, periodically entering a nuclear compartment where CDC-25.1 is abundant

A novel additive manufacturing method of cellulose gel

Screen-additive manufacturing (SAM) is a potential method for producing small intricate parts without waste generation, offering minimal production cost. A wide range of materials, including gels, can be shaped using this method. A gel material is composed of a three-dimensional cross-linked polymer or colloidal network immersed in a fluid, known as hydrogel when its main constituent fluid is water. Hydrogels are capable of absorbing and retaining large amounts of water. Cellulose gel is among the materials that can form hydrogels and, as shown in this work, has the required properties to be directly SAM, including shear thinning and formation of post-shearing gel structure. In this study, we present the developed method of SAM for the fabrication of complex-shaped cellulose gel and examine whether successive printing layers can be completed without delamination. In addition, we evaluated cellulose SAM without the need for support material. Design of Experiments (DoE) was applied to optimize the SAM settings for printing the novel cellulose-based gel structure. The optimum print settings were then used to print a periodic structure with micro features and without the need for support material

3D Printed Stirling Engines for Education of Machine Design and Analysis

The recent proliferation of low to medium cost additive manufacturing equipment opens a doorway to using the technology for aiding the education of many engineering principles. Stirling cycle engines are highly complex thermodynamic machines that, if delved into, demonstrate many mechanical engineering disciplines. Importantly fully functional engines, using safe hot and cold water as the energy source, can be made by polymer additive manufacture using commonly available materials and printing machines. This process somewhat negates the need to invest in high cost laboratory demonstration equipment. It also allows remote and poorly funded institutions or individuals to work with live equipment. This publication will demonstrate the use of additive manufactured Stirling Engines for effective teaching in creative design, optimization product development, thermodynamics, mechanics, computational fluid dynamics, finite element analysis, live data acquisition, material science and additive manufacture

Cytokinesis in bloodstream stage Trypanosoma brucei requires a family of katanins and spastin

Microtubule severing enzymes regulate microtubule dynamics in a wide range of organisms and are implicated in important cell cycle processes such as mitotic spindle assembly and disassembly, chromosome movement and cytokinesis. Here we explore the function of several microtubule severing enzyme homologues, the katanins (KAT80, KAT60a, KAT60b and KAT60c), spastin (SPA) and fidgetin (FID) in the bloodstream stage of the African trypanosome parasite, Trypanosoma brucei. The trypanosome cytoskeleton is microtubule based and remains assembled throughout the cell cycle, necessitating its remodelling during cytokinesis. Using RNA interference to deplete individual proteins, we show that the trypanosome katanin and spastin homologues are non-redundant and essential for bloodstream form proliferation. Further, cell cycle analysis revealed that these proteins play essential but discrete roles in cytokinesis. The KAT60 proteins each appear to be important during the early stages of cytokinesis, while downregulation of KAT80 specifically inhibited furrow ingression and SPA depletion prevented completion of abscission. In contrast, RNA interference of FID did not result in any discernible effects. We propose that the stable microtubule cytoskeleton of T. brucei necessitates the coordinated action of a family of katanins and spastin to bring about the cytoskeletal remodelling necessary to complete cell divisio

The Warden Attitude: An investigation of the value of interaction with everyday wildlife

Using a discrete choice experiment, we elicit valuations of engagement with ‘everyday wildlife’ through feeding garden birds. We find that bird-feeding is primarily but not exclusively motivated by the direct consumption value of interaction with wildlife. The implicit valuations given to different species suggest that people prefer birds that have aesthetic appeal and that evoke human feelings of protectiveness. These findings suggest that people derive wellbeing by adopting a warden-like role towards ‘their’ wildlife. We test for external validity by conducting a hedonic analysis of sales of bird food. We discuss some policy implications of the existence of warden attitudes

Fabrication of a compliant phantom of the human aortic arch for use in Particle Image Velocimetry (PIV) experimentation

Compliant phantoms of the human aortic arch can mimic patient specific cardiovascular dysfunctions in vitro. Hence, phantoms may enable elucidation of haemodynamic disturbances caused by aortic dysfunction. This paper describes the fabrication of a thin-walled silicone phantom of the human ascending aorta and brachiocephalic artery. The model geometry was determined via a meta-analysis and modelled in SolidWorks before 3D printing. The solid model surface was smoothed and scanned with a 3D scanner. An offset outer mould was milled from Ebalta S-Model board. The final phantom indicated that ABS was a suitable material for the internal model, the Ebalta S-Model board yielded a rough external surface. Co-location of the moulds during silicone pour was insufficient to enable consistent wall thickness. The resulting phantom was free of air bubbles but did not have the desired wall thickness consistency

A glimpse of the ERM proteins

In all eukaryotes, the plasma membrane is critically important as it maintains the architectural integrity of the cell. Proper anchorage and interaction between the plasma membrane and the cytoskeleton is critical for normal cellular processes. The ERM (ezrin-radixin-moesin) proteins are a class of highly homologous proteins involved in linking the plasma membrane to the cortical actin cytoskeleton. This review takes a succinct look at the biology of the ERM proteins including their structure and function. Current reports on their regulation that leads to activation and deactivation was examined before taking a look at the different interacting partners. Finally, emerging roles of each of the ERM family members in cancer was highlighted