DSMC simulations of neutral gas flow in the DTT particle exhaust system

Divertor Tokamak Test Facility (DTT) is a new European superconducting tokamak, currently under final design, addressed to investigate alternative power exhaust solutions for DEMO. Although the divertor system is not finalized yet, the machine and port geometry set limitations on the divertor pumping system operational space. A numerical study of neutral gas dynamics in the divertor region is performed based on the DSMC method by applying the DIVGAS code. The study includes both single-null (SN) and double-null (DN) divertor configurations. For both configurations, the SolEdge2D–EIRENE plasma simulations have been performed for a deuterium plasma with neon seeding and the extracted information about the neutral particles on the predefined interfaces is imposed as incoming boundary conditions for DIVGAS simulations. In the SN case, two plasma puffing scenarios and three candidate pumping port arrangements have been considered. The divertor dome influence on the pumped fluxes can reach 50%. An increase of the capture coefficient six times leads to a decrease in the pressure at the pumping openings by a factor of about 4.5–7. The influence of the size of the lower vertical opening has been studied showing that the enlarged vertical port may establish as the main pumping opening. In the DN case, when the pumping is performed from both lower and upper divertor the overall pumped fluxes at the upper divertor are always higher than the corresponding ones for the lower divertor by a factor of 2–2.5, mainly due to the difference in the pumping areas. In both SN and DN cases, the neutrals outflux toward the X-point dominates the particle transport in the private flux region. The operational space provided by this first assessment is relatively stable against modified classical divertor geometries and allows a more thorough assessment of the pumping technology of the DTT fusion device in the future.

Ergonomic Bench to Decrease Postural Risk Level on the Task of Changing Forklift's Brake Pads

Development of musculoskeletal disorders caused by awkward postures are present in tasks performed in small companies. Consequently, this chapter evaluates the postural risk level associated to the task of changing brake pads of a forklift, and proposes the design and the implementation of an ergonomic bench that helps to reduce this level of postural risk. As methods, postural risk level corresponding to the task was determined using REBA, whereas anthropometric analysis was developed, and axiomatic design and TRIZ methodologies were used to develop the proposed design. Results showed a REBA score of 8 (high-risk level). The final design is done of nylamid, and it contains some TRIZ principle, such as copying, extraction, and dynamicity. Respect axiomatic design, the bench meets some functional requirements, such as support the user's weight, avoid unsafety conditions, and be adjustable. With the TRIZ principles and functional requirements, this bench will help diminish postural risk level.

Establishment of data centre at Mzuzu University: A survey of anticipations and aspirations of key project stakeholders

Mzuzu University lost its Library as a result of a fire that took place on December 18, 2015. In response, the university established two processes to ensure the library services were not interrupted. The first process was to restore information services within six months by creating an interim Library. The second was to design a new library in collaboration with Virginia Tech’s School of Architecture and Design in the United States. A total of three conceptual designs were developed, from which Mzuzu University selected a final design. One key aspect of each conceptual design was a dedicated space for a data centre. The initial concept was that the data centre would support research activities at the University, within Malawi, and with international partners outside Malawi, such as Virginia Tech. This paper captures the anticipations and aspirations of the key stakeholders involved with the library design project at Mzuzu University in Malawi and Virginia Tech in the USA. Data were captured by a survey that was shared via email with 29 stakeholders. A total of 10 responded at Mzuzu University, and 12 responded at Virginia Tech. A key finding from the survey was the need to create clear plans for each aspect of the project to ensure the effective implementation of the data centre. Critical aspects to the project include staffing, equipment procurement, the management of the data centre, data literacy programming, and the long-term sustainability of the data centre. Developing a policy/process to guide the operations of the data centre was also found to be critical. The library construction began in February 2021 and is expected to end in February 2023. Having a clear plan for how the data centre could be operationalized will be essential to ensuring the centre is successful. The data centre will be a new facility for the university and this paper is a first step towards shaping the requirements of, and potential for, this new facility.

A Fully 3D-Printed Steerable Instrument for Minimally Invasive Surgery

In the field of medical instruments, additive manufacturing allows for a drastic reduction in the number of components while improving the functionalities of the final design. In addition, modifications for users’ needs or specific procedures become possible by enabling the production of single customized items. In this work, we present the design of a new fully 3D-printed handheld steerable instrument for laparoscopic surgery, which was mechanically actuated using cables. The pistol-grip handle is based on ergonomic principles and allows for single-hand control of both grasping and omnidirectional steering, while compliant joints and snap-fit connectors enable fast assembly and minimal part count. Additive manufacturing allows for personalization of the handle to each surgeon’s needs by adjusting specific dimensions in the CAD model, which increases the user’s comfort during surgery. Testing showed that the forces on the instrument handle required for steering and grasping were below 15 N, while the grasping force efficiency was calculated to be 10–30%. The instrument combines the advantages of additive manufacturing with regard to personalization and simplified assembly, illustrating a new approach to the design of advanced surgical instruments where the customization for a single procedure or user’s need is a central aspect.

AN INHERENTLY SAFER LAYOUT DESIGN FOR THE LIQUEFACTION PROCESS OF AN FLNG PLANT

Floating Liquefied Natural Gas (FLNG) facilities have limited space available and a high possibility of accidents occurring. The severity of consequences requires an inherently safer layout design. Scope of the liquefaction process requires to determine the size of utilities, operating costs, the deck area and the number of LNG trains. The layout of the liquefaction process plays a key role in defining operational and economical safety of the whole FLNG plant. The present study focuses on developing a novel methodology to design an inherently and optimally safer layout for the generic multi-deck liquefaction process of an FLNG plant. The integrated inherent safety principle is applied at the early phases of the layout design considering inherent safety and cost indices in three different layout options, and for the final design the most optimal option was selected. The proven indexing approach quantified the associated risks in all units. Safety measures were undertaken to eliminate or reduce the risk to an acceptable level. The results showed that the economic losses due to domino effects were limited by an improved layout design and passive control strategies. This study only dealt with evaluation and analysis of critical units of the plant due to a lack of detailed information at the early phase of the design. However, the proposed method plays a positive role in obtaining an inherently safer layout design of any multi-deck plants.

HULLFORM & HYDRODYNAMIC CONSIDERATIONS IN THE DESIGN OF THE UK FUTURE AIRCRAFT CARRIER (CVF)

An overview is provided of the manner in which hydrodynamic and hullform-related design considerations were addressed in the development of the BAE SYSTEMS team’s design proposal for the UK Future Aircraft Carrier (CVF). It also outlines how broader design considerations such as aviation, survivability and supportability requirements influenced these aspects of the design. A summary is also provided of some of the more detailed requirements development, option assessment and performance evaluation work that has been undertaken. The aircraft carrier designs discussed in this paper correspond to the BAE SYSTEMS team’s final design submission as it stood in January 2003, at the time it was discontinued by the UK Ministry of Defence, in favour of the rival Thales / BMT team design that has since been developed into the UK Royal Navy’s new ‘Queen Elizabeth’ class aircraft carrier. This final BAE SYSTEMS design submission consisted of two distinct design variants - one configured to operate a CTOL-based air group, the other configured to accommodate a STOVL air group. Both variants were based on a common ‘core’ ship design. The discussion presented in this paper is applicable to both variants.

Design and Fabrication of a New MHD Micropump for Continuous Subcutaneous Infusion to Thalassemia Major Patients

Background: In recent decades, reducing the size of the drug delivery systems along with precise control of the amount of drug pumped, has attracted the attention of many researchers. Objectives: The slow subcutaneous infusion of the deferoxamine in thalassemia major patients during day is of vital importance either for the drug effectiveness. However, this is difficult to achieve due to the large size of the conventional infusion pumps and their high weight. Therefore, size and weight reduction of the infusion pumps are very important issues that must be well addressed. Methods: A biomedical micropump for drug solution infusion to human body based on the magnetohydrodynamic (MHD) concept is and designed, and its performance experimentally is investigated in this research. The key challenge in the fabrication of the micropump is its size, weight, bubble generation, and high operating voltage. Results: The present design is well responded to these problems. The final design operates with a 1.2 v without any bubble generation, while its size and weight are 20 × 40 × 50 mm3 and 90 grams, respectively. The size of the micropump is about 1/3 size of conventional micropump, while its weight is half of them. Conclusions: Therefore, the newly designed micropump has the ability to inject the drug solution to thalassemia major patients with a sufficient infusion rate during the day without disturbing them, so it can increase their quality of life and increase their life expectancy.

Study and Optimization of Field Limiting Rings for 10kV SiC Insulated Gate Bipolar Transistor

A 10kV-level silicon carbide (SiC) insulated gate bipolar transistor (IGBT) with field limiting rings (FLRs) is designed and simulated with Sentaurus TCAD, the detailed optimization method and comparisons are presented in this paper. Linearly varying spacing between rings is introduced to SiC IGBT and adjustment is performed on width of rings, the final structure achieves a breakdown voltage over 12kV with a termination length of 164.5 µm , which is 69.93% lower than that of conventional structure with a fixed ring spacing. Moreover, the final design can decrease the sensitivity to the interface charges, the tolerance to positive surface charges exceeds 8 × 10 11 cm − 2 , which is 3.5 times that of the conventional structure. Besides, double pulse measurements prove no degradation of conduction and switching characteristics.

Mastering Maungawhau

<p>The Aotearoa (New Zealand) housing crisis and environmental shifts have inspired this thesis, which will address contemporary issues regarding Landscape Architecture, housing and urban design in Maungawhau (Mount Eden), Tāmaki-Makaurau (Auckland). Certain design decisions and some areas of local and national policy have restricted property development (or allowed poor development to occur). These developments have also limited infrastructural progress particularly in regard to sustainable urban planning strategies throughout Tāmaki-Makaurau in the past two decades in particular. The population of Tāmaki-Makaurau is rapidly growing, the 2018 census revealed a population increase of 11% in the past five years. Tāmaki-Makaurau is home to roughly 1.6million people, which is 1/3rd of Aotearoa‘s population. House prices reached an all-time high in 2016, causing major concern at a national level. To tackle these issues of improving sustainable infrastructure and high-density housing this thesis will create a design strategy which will form a new urban fabric for Eden Park. The Master Planning strategy will take a cross-disciplinary approach. Involving Landscape Architecture, elements or urbanism, architecture and hydrology. The landscape, and water sensitive design will be the key drivers in how the housing mosaic is formed. Eden Park will be used as a blank canvas site of 105,300m2. The applied design will evolve as the site challenges the aims of the thesis, methods will be tested and the project will adapt as the site develops, the implementation of precedent and methods will be displayed in the design development and final design. This will result in a robust Master Planning strategy. A detailed urban design strategy will be a solution to the challenges set out in the thesis statement. The design development for Eden Park will intertwine with the wider Maungawhau network, this will be displayed in the final design drawings. The wetland will aim to treat a larger catchment of the area of 1,026,130.33m2, this means that the wetland will need to be roughly 20,000m2 so that the total catchment can be treated by this artificial wetland at 2%. The design goal is to create a multi-layered high-density housing assemblage and mixed use space that will stand as an example of a contemporary water sensitive and high-density design in action. The final design will be strong, versatile, and have the potential to be developed and expanded into wider networks over time in regard to using similar design strategy. I envisage a successful landscape design framework as a tool that aims to design more cohesive, innovative, adaptive and local high-density urban plans, which will respond to the demands of a growing population, ever-changing environmental conditions, and overall enhance a better quality of life.</p>

Common unity: reconnecting people with the environment through indigenous values and participatory design

<p>A significant problem for struggling communities in New Zealand is disconnection from the environment and a loss of cultural values. These issues cause disengagement and division between the people and the environment. Social stability gradually declines, leading to participation within one’s community being discouraged. Investigations into community engagement and the enhancement of the community environment suggest there has been a failure to address the current issues affecting struggling communities. Disconnect and disregard for Indigenous values in communities prove to be a defining factor in the relationship between people and the environment. Indigenous Māori incorporated Mātauranga (knowledge), Tikanga (customs) and Māori values in their way of life which proved instrumental in their development and sense of Kotahitanga (unity) between themselves and with the environment. This allowed Māori to become one with the land and for Whanaungatanga (sense of belonging) and Kaitiakitanga (guardianship of the land) to spread through the people. However, these values have been compromised and subsequently lost due to the European influence on the land and on Māori people. There needs to be a vigorous search for answers on how to reconnect people with these values so as to build strong and united communities. This design research looks at ways of enhancing the struggling community of Takapūwāhia, Porirua, and the local iwi, Ngāti Toa. It seeks to address problems of disconnect, disengagement and loss of values between the environment and the people. This research aims to answer the research question ‘How can we unite a community by implementing Indigenous values when designing for people?’ The first step will be to undertake a literature review and evaluation of various case studies relevant to the research question. Then community engagement will take place so people can come together to evaluate existing problems and to enable the voice and vision of the people to influence the final design outcome. Effective methods of community engagement will be employed through Participatory and Consultative Design which will provide ways of communicating ideas and solutions. Design experiments will be carried out on the identified problem degraded sites within the Takapūwāhia community. These will be presented back to the community with participation with other community members in the design process, contributing to community growth and identity. With the key objective of the research being to unite the Takapūwāhia community, this will be achieved through their voice and their vision being integral to the design outcome, which will portray a story unique to the people of Ngāti Toa and to Takapūwāhia, exploring Māori symbolism essential to Ngāti Toa and integrating Māori values with Landscape Architecture. This will connect people to the design, this particular place and to the environment and help achieve the goal of the project of creating a sense of unity, ownership and belonging, of Kotahitanga, Whanaungatanga and Kaitiakitanga.</p>