ARCHITECTURAL AND PSYCHOLOGICAL ASPECTS IN OPTIMIZED RADIATION SHIELDING DESIGN FOR SPACE APPLICATIONS

NewSpace bears all the hallmarks of past revolutions in technology. Since we have other examples of exponential growth of specific technologies, we should maximize the economic and engineering potential of this movement by expanding the envelopes for long term crewed habitats in deep space. We should also take an approach that minimizes waste in both design and fabrication as these bases expand. This paper provides a systematic approach to habitats optimized for volume, radiation protection, crew psychology, reusability, affordability, crowd-sourced subsystem design, and expansion. These habitats and systems are designed to be as “future proof” as possible to allow rapid and safe technological advancement within the structures. One of major “showstoppers” of human space exploration is cosmic and solar events radiation. It is a serious problem that may cause cancer and other types of tissue damage and equipment malfunction. It has to be addressed in space vehicles design especially for long-term space exploration missions and future Moon or Mars surface settlements. This paper discusses a unique layered system incorporated into a habitat structure, which may help to reduce the radiation hazard to the crew and interior equipment and systems. The paper also argues that a successful mitigation of radiation impact on human health should be based on a multidisciplinary methodology that also includes psychophysiological approach to the problem. Multiple techniques and practices to minimize psychological stress that may suppress immune system and reduce resistance to cancer, are presented and compared. Conclusions are drawn upon results of those comparisons and a multidisciplinary design concept is proposed to be applied both in long-duration human space exploration missions and in radioactive environment on Earth

PRACTICAL DESIGN EXAMPLES FOR HUMAN HABITATS IN SPACE, OFF-GRID, AND IN LOW-IMPACT COMMUNITIES

All human habitat problems fall into three major categories- the environment, the habitat itself, and the occupants. By breaking these problems down into common themes and addressing them directly, we can build a common knowledge base for all three challenges faced by humanity. A crew living in space has the new problems of coping with radiation, microgravity, and vacuum. All the while, they are dealing the usual issues of eating, sleeping, and getting along with the rest of the occupants. By isolating the differences between space and earth habitats, we can create common architectural styles for each human habitat challenge where commonality is appropriate. We can then examine the differences, then isolate and modularize the secondary systems where possible. This simplifies experimentation and testing of the physical and psychological design of a structure on Earth prior to attempting use in space. It also allows spin-off architectures for extreme environments, off-grid settlements, research bases, and low impact communities on Earth. By isolating and testing each attribute of the system in parallel with control groups, we can scientifically refine the systems for human shelter regardless of environment. This paper will show numerous examples of architectures designed for space or space analog research bases. These designs can be both de-scoped to off-grid sustainable architecture, and scoped up for space habitat applications. Concepts such as internal greenhouses, enclosed permaculture, thermal protection, energy management, and radiation shielding are included for both minimal habitats and large bases. These systems can then be applied for disaster first responders, research bases in extreme environments, o-grid homes, and low-impact communities

Existing and new proposals of Space analog, off-grid and sustainable habitats with Space applications

All human habitat problems fall into three major categories – the environment, the habitat itself, and the occupants. By breaking these problems down into common themes and addressing them directly, we can build a common knowledge base for all three challenges faced by humanity. A crew living in space has the new problems of coping with radiation, microgravity, and vacuum. Meanwhile, they are dealing with the usual issues of eating, sleeping, and getting along with the rest of the occupants. By isolating the differences between space and earth habitats, we can create common architectural approaches for each human habitat challenge where commonality is appropriate. We can then examine the differences, and finally isolate and modularize the secondary systems where possible. This simplifies experimentation and testing of the physical and psychological design of a structure on Earth prior to attempting to use it in space. It also allows spin-off architectures for extreme environments, off-grid settlements, research bases, and low-impact communities on Earth with applications for self-sustainable building. This paper will show numerous examples of architectures designed for space or space-analog research bases. These designs can be both descoped to off-grid sustainable architecture, and scoped up for space habitat applications. Concepts such as internal greenhouses, enclosed permaculture, thermal protection, energy management, and radiation shielding are included for both minimal habitats and large bases. These systems can be applied for disaster first responders, research bases in extreme environments, off-grid homes, and low-impact communities. Examples of these applications are also presented in this paper with a series of projects developed by the authors

Vitamin E diffused highly cross-linked polyethylene in total hip arthroplasty at five years:a randomised controlled trial using radiostereometric analysis

Aims The objective of this five-year prospective, blinded, randomised controlled trial (RCT) was to compare femoral head penetration into a vitamin E diffused highly cross-linked polyethylene (HXLPE) liner with penetration into a medium cross-linked polyethylene control liner using radiostereometric analysis. Patients and Methods Patients scheduled for total hip arthroplasty (THA) were randomised to receive either the study E1 (32 patients) or the control ArComXL polyethylene (35 patients). The median age (range) of the overall cohort was 66 years (40 to 76). Results The five-year median (interquartile range) proximal femoral head penetration into the E1 was -0.05 mm (-0.13 to -0.02) and 0.07 mm (-0.03 to 0.16) for ArComXL. At three and five years, the penetration was significantly greater in the ArComXL group compared with the E1 group (p = 0.029 and p = 0.019, respectively). All patient-reported outcomes (PROs) improved significantly from the pre-operative interval compared with those at one year, and remained favourable at five years. There were no differences between the two groups at any interval. Conclusion The five-year results showed that E1 polyethylene does not wear more than the control, ArComXL. This is the longest-term RCT comparing the wear performance and clinical outcome of vitamin E diffused HXLPE with a previous generation of medium cross-linked polyethylene. Cite this article: Bone Joint J 2017;99-B:577–84. </jats:sec

Precision of radiostereometric analysis (RSA) of acetabular cup stability and polyethylene wear improved by adding tantalum beads to the liner

<div><p><b>Background and purpose —</b> In traditional radiostereometric analysis (RSA), 1 segment defines both the acetabular shell and the polyethylene liner. However, inserting beads into the polyethylene liner permits employment of the shell and liner as 2 separate segments, enabling distinct analysis of the precision of 3 measurement methods in determining femoral head penetration and shell migration.</p><p><b>Patients and methods —</b> The UmRSA program was used to analyze the double examinations of 51 hips to determine if there was a difference in using the shell-only segment, the liner-only segment, or the shell + liner segment to measure wear and acetabular cup stability. The standard deviation multiplied by the critical value (from a t distribution) established the precision of each method.</p><p><b>Results —</b> Due to the imprecision of the automated edge detection, the shell-only method was least desirable. The shell + liner and liner-only methods had a precision of 0.115 mm and 0.086 mm, respectively, when measuring head penetration. For shell migration, the shell + liner had a precision of 0.108 mm, which was better than the precision of the shell-only method. In both the penetration and migration analyses, the shell + liner condition number was statistically significantly lower and the bead count was significantly higher than for the other methods.</p><p><b>Interpretation —</b> Insertion of beads in the polyethylene improves the precision of femoral head penetration and shell migration measurements. A greater dispersion and number of beads when combining the liner with the shell generated more reliable results in both analyses, by engaging a larger portion of the radiograph.</p></div