Testing campaign for ECRIDA: the UV resin 3D printer flying on REXUS

ECRIDA is a student project participating in the REXUS/BEXUS campaign that develops a UV resin 3D printer device capable of working in the low-gravity environment offered by the REXUS rocket flight. Our main objective is to describe the impact of low gravity on the UV resin 3D printing process by comparing samples printed on Earth with samples printed in space. Due to the requirements of the host vehicle and driven by the novel design of our device, a thorough testing campaign must be planned and completed to qualify the device for flight and maximise the success of the scientific objectives. This paper describes the requirements that the device must fulfil and goes into the design of our test plan describing the procedures and the results. Vacuum, vibration, pressure, and functional tests were performed and described together with our learned lessons and conclusions in our will to help student teams with their testing activitie

End-to-end process of hollow spacecraft structures with high frequency and low mass obtained with in-house structural optimization tool and additive manufacturing

In the space sector the most decisive elements are: mass reduction, cost saving and minimum lead time; here, structural optimization and additive layer manufacturing (ALM) fit best. The design must be driven by stiffness, because an important requirement for spacecraft (S/C) structures is to reduce the dynamic coupling between the S/C and the launch vehicle. The objective is to create an end-to-end process, from the input given by the customer to the manufacturing of an aluminum part as light as possible but at the same time considerably stiffer while taking the full advantage of the design flexibility given by ALM. To design and optimize the parts, a specialized in-house tool was used, guaranteeing a load-sufficient material distribution. Using topological optimization, the iterations between the design and the stress departments were diminished, thus greatly reducing the lead time. In order to improve and lighten the obtained structure a design with internal cavities and hollow beams was considered. This implied developing of a procedure for powder evacuation through iterations with the manufacturer while optimizing the design for ALM. The resulted part can be then manufactured via ALM with no need of further design adjustments. To achieve a high-quality part with maximum efficiency, it is essential to have a loop between the design team and the manufacturer. Topological optimization and ALM work hand in hand if used properly. The team achieved a more efficient structure using topology optimization and ALM, than using conventional design and manufacturing methods

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Study regarding the influence of airbag deployment time on the occupant injury level during a frontal vehicle collision

The aim of this paper was to analyse the influence of airbag deployment delay upon the head of the occupant in the case of frontal collision using simulations in PC Crash and MADYMO dummy as the occupant. The study will also take into account the pretension delay of the seat-belt which is activated along with the airbag. Frontal airbags on both the passenger and the driver were analysed including the occupant kinematics during the collision. Also, to validate the simulation, a comparison was done with a real crash test. We predict that by increasing the delay of deployment, the head acceleration will increase due to the fact the head travels close to the instrument panel/steering wheel, and the force of the airbag will generate a significant acceleration upon the head. To better assess the potential injury of the occupant, the head injury criteria (HIC) will be calculated and correlated with the Abbreviated injury scale (AIS) code

Closing Force Evaluation of a Sample Return Capsule for a Phobos Sample Return Mission

The mission objective of the Phobos Sample Return is to collect and return 100 g of Phobos’ surface material to Earth inside a tight enclosure composed of a Vault, a Sample Container and sealing elements. One important aspect of the project was the development of a closing mechanism capable of ensuring a pushing force high enough compared to the available force of the robotic arm (40 N). The need for a higher pushing force derived from the design tests which were carried out to experimentally determine the necessary force to overcome the resistance of the sealing element when the vault is closed. Two types of sealing elements, custom made for this project, along with two SC with different geometrical shapes in the sealing area were tested. For better accuracy, the tests considered the imposed operational temperature domain for the vault, ECSS standards and the test rig set-up being performed at environmental temperature (+20 °C), −20 °C, −60 °C and +70 °C. The results of the tests highlighted that the negative temperature has a significant influence over the closing force, as this force is increasing once the operational temperature is decreasing. Based on the work performed, the most suitable type of sealing element was identified, in particular the piston geometry which allows a smaller force to close the vault

Pandemic lockdown, healthcare policies and human rights: integrating opposed views on COVID-19 public health mitigation measures

The issue of the COVID-19 pandemic occupies the agenda of the whole world. The pivot of this pandemic is a crucial element that has become almost as important as the virus itself, namely the lockdown. Although, the rationale for lockdown is well-sustained by strong epidemiological arguments, exploring the 'other' unwanted consequences of the contemporary COVID-19 pandemic is mandatory for coagulating a robust agreed position against the numerous problems generated by the SARS-CoV-2 virus. Starting from the rationale of the lockdown, in this paper we explored and exposed the other consequences of the COVID19 pandemic measures such as the use or abuse of human rights and freedom restrictions, economic issues, marginalized groups and eclipse of all other diseases. Our scientific attempt is to coagulate a stable position and integrate current opposing views by advancing the idea that rather than applying the uniform lockdown policy, one could recommend instead an improved model targeting more strict and more prolonged lockdowns to vulnerable risk/age groups while enabling less stringent measures for the lower-risk groups, minimizing both economic losses and deaths. Rigorous (and also governed by freedom) debating may be able to synchronize the opposed perspectives between those advocating an extreme lockdown (e.g., most of the epidemiologists and health experts), and those criticizing all restrictive measures (e.g., economists and human rights experts). Confronting the multiple facets of the public health mitigation measures is the only way to avoid contributing to history with yet another failure, as seen in other past epidemics

A Study on Using the Additive Manufacturing Process for the Development of a Closed Pump Impeller for Mechanically Pumped Fluid Loop Systems

The efficiency of a centrifugal pump for mechanical pump fluid loops, apart from the design, relies on the performance of the closed impeller which is linked to the manufacturing process in terms of dimensional accuracy and the surface quality. Therefore, the activities of this paper were focused on defining the manufacturing process of a closed impeller using the additive manufacturing technology for mechanically pumped fluid loop (MPFL) systems in space applications. Different building orientations were studied to fabricate three closed impellers using selective laser melting technology and were subjected to dimensional accuracy and surface quality evaluations in order to identify the optimal building orientation. The material used for the closed impeller is Inconel 625. The results showed that both geometrical stability and roughness were improved as the building orientation increased, however, the blade thickness presented small deviations, close to imposed values. Finishing processes for inaccessible areas presented significant results in terms of roughness, nevertheless, the process can be further improved. Abrasive flow machining (AFM) post-processing operations have been considered and the results show major improvements in surface quality. Thus, important steps were made towards the development of complex structural components, consequently increasing the technological readiness level of the additive manufacturing process for space applications

Taking That Perfect Aerial Photo: A Synopsis of Interactions for Drone-based Aerial Photography and Video

Personal drones are more and more present in our lives and acting as “flying cameras” is one of their most prominent applications. In this work, we conduct a synopsis of the scientific literature on human-drone interaction to identify system functions and corresponding commands for controlling drone-based aerial photography and video, from which we compile a dictionary of interactions. We also discuss opportunities for more research at the intersection of drone computing, augmented vision, and personal photography

The Impact of Cancer Stem Cells in Colorectal Cancer

Despite incessant research, colorectal cancer (CRC) is still one of the most common causes of fatality in both men and women worldwide. Over time, advancements in medical treatments have notably enhanced the survival rates of patients with colorectal cancer. Managing metastatic CRC involves a complex tradeoff between the potential benefits and adverse effects of treatment, considering factors like disease progression, treatment toxicity, drug resistance, and the overall impact on the patient’s quality of life. An increasing body of evidence highlights the significance of the cancer stem cell (CSC) concept, proposing that CSCs occupy a central role in triggering cancer. CSCs have been a focal point of extensive research in a variety of cancer types, including CRC. Colorectal cancer stem cells (CCSCs) play a crucial role in tumor initiation, metastasis, and therapy resistance, making them potential treatment targets. Various methods exist for isolating CCSCs, and understanding the mechanisms of drug resistance associated with them is crucial. This paper offers an overview of the current body of research pertaining to the comprehension of CSCs in colorectal cancer