Dimethylsilanediol (DMSD) Source Assessment and Mitigation on ISS: Estimated Contributions from Personal Hygiene Products Containing Volatile Methyl Siloxanes (VMS)

Dimethylsilanediol (DMSD) is a small organosilicon compound present in humidity condensate on the International Space Station. Aqueous DMSD originates from volatile methyl siloxane (VMS) compounds in the ISS cabin atmosphere. DMSD is not effectively removed by the WPA (Water Processor Assembly), requiring removal and replacement of both WPA Multifiltration (MF) Beds for an estimated resupply penalty of approximately 70 kg/year. Analyses indicate that WPA can handle DMSD if the concentration in the condensate can by reduced by fifty percent. Personal Hygiene Products (PHPs) used by crew are suspected to be a significant source of VMS. Source removal of VMS will be required to achieve a measurable impact to the DMSD concentration in the condensate. The inventory of total crew provisions for ISS was analyzed to identify silicon containing materials and products used for personal hygiene that emit VMS. Accounting for the wide range in mass of hygiene product applied to skin or hair, the frequency of application, the product selection, the number of crew using a given product, the range in silicon mass fraction of different products, and the potential vaporization of the product, the potential total VMS emissions from personal hygiene products for a crew of six on ISS were estimated. The total daily VMS emissions from PHPs estimate ranges from 261 to 1145 mg-Si per day, compared to total estimated VMS generation rates on ISS of 800 to 1500 mg-Si per day. The main sources of VMS were determined to be antiperspirants (173 to 696 mg-Si per day), skin lotions (63 to 248 mg-Si per day), wipes (25 to 124 mg-Si per day) and hair conditioner (0 to 69 mg-Si per day). Several siloxanes-free options are available for deodorants, wet wipes, lotions, and leave-in conditioners. These products are now being assessed for crew member use in future increments

The Interconnected Magmatic Plumbing System of the Natron Rift

Understanding the magmatic plumbing system of rift volcanoes is essential when examining the interplay between magmatic and tectonic forces. Recent seismicity, volcanic activity, magma emplacement, and volatile release make the Natron basin the ideal location to study these processes in the East African Rift System. Here, we present the first high-resolution tomographic imaging of Oldoinyo Lengai volcano and surrounding volcanic systems using attenuation mapping. High scattering and absorption features reveal fluid-filled fracture networks below regions of magmatic volatile release at the surface and a close spatial association between carbonatite volcanism and deeply penetrating, fluid-filled faults. High-absorption features appear sensitive to fluids and thermal gradients, revealing a central sill complex and connected plumbing system down to the mid-crust, which links volcanoes and rift segments across the developing magmatic rift

Exploring osteoporosis sufferers knowledge on sedentary behaviour in the management of their disease

Objectives: 1) To develop an understanding of the thoughts and opinions of older women diagnosed with osteoporosis regarding sedentary behaviour and 2) Investigate strategies used to reduce sedentary behaviour for future intervention development. Methods: Eleven older women with osteoporosis (mean age=68.2y±6.6(SD)) participated in semi-structured interviews (March-May 2020). They were recruited from the Royal Osteoporosis Society (Scottish) support group networks and the Strathclyde Age-Friendly-Academy. Telephone interviews were recorded, transcribed verbatim and thematically analysed using Braun & Clarke (2006). Results: Three main themes emerged: ‘Older Women’s Knowledge’, ‘Motivators to reduce Sedentary Behaviour’ and ‘Older Adult’s and Technology’. Participants reported an increase/maintenance of physical activity levels after osteoporosis diagnosis, had a good understanding and awareness of sedentary behaviour and how it affects health holistically. Participants identified motivators to interrupt sedentary behaviour (e.g. family/friends) and facilitators of sedentary behaviour (e.g. Television). Technology appeared to be used widely among participants to track movement patterns (e.g. Fitbit) but access and usability were identified as potential barriers when using technology to reduce sedentary behaviour among older adults. Conclusion: Knowledge does not appear to be a factor that needs addressing in relation to sedentary behavior in older women diagnosed with osteoporosis. Identified motivators and barriers could increase awareness of sedentary behaviour among older adults

Visualising transformative spaces for education: a focus on lecture halls, computer rooms and studios

One room, three learning spaces for creative education. This image-led investigation shows how a standard blank room can be effectively transformed into three different kinds of learning environments: a lecture hall, a computer room and a studio. Research has shown that effective design of teaching spaces is beneficial to the learning experience and contributes to creating a more engaging relationship between teachers and learners. On the other hand, few visual resources have been produced to support this in the UK. This article seeks to fill this gap. The design of these classrooms applies Basye’s idea of campfire to stimulate and support interaction between teachers and learners. In particular, these visuals show how technology can improve the students’ experience of the lecture hall, provide adequate lighting, personal space and drawing devices in the computer room, and finally how gathering in a circle may replicate the benefits of campfires in the studio

Local Eigenvalue Density for General MANOVA Matrices

We consider random n\times n matrices of the form (XX*+YY*)^{-1/2}YY*(XX*+YY*)^{-1/2}, where X and Y have independent entries with zero mean and variance one. These matrices are the natural generalization of the Gaussian case, which are known as MANOVA matrices and which have joint eigenvalue density given by the third classical ensemble, the Jacobi ensemble. We show that, away from the spectral edge, the eigenvalue density converges to the limiting density of the Jacobi ensemble even on the shortest possible scales of order 1/n (up to \log n factors). This result is the analogue of the local Wigner semicircle law and the local Marchenko-Pastur law for general MANOVA matrices.Comment: Several small changes made to the tex

Quantum conductance problems and the Jacobi ensemble

In one dimensional transport problems the scattering matrix $S$ is decomposed into a block structure corresponding to reflection and transmission matrices at the two ends. For $S$ a random unitary matrix, the singular value probability distribution function of these blocks is calculated. The same is done when $S$ is constrained to be symmetric, or to be self dual quaternion real, or when $S$ has real elements, or has real quaternion elements. Three methods are used: metric forms; a variant of the Ingham-Seigel matrix integral; and a theorem specifying the Jacobi random matrix ensemble in terms of Wishart distributed matrices.Comment: 10 page

Physical interpretation of the Wigner rotations and its implications for relativistic quantum information

We present a new treatment for the spin of a massive relativistic particle in the context of quantum information based on a physical interpretation of the Wigner rotations, obtaining different results in relation to the previous works. We are lead to the conclusions that it is not possible to define a reduced density matrix for the particle spin and that the Pauli-Lubanski (or similar) spin operators are not suitable to describe measurements where spin couples to an electromagnetic field in the measuring apparatus. These conclusions contradict the assumptions made by most of the previous papers on the subject. We also propose an experimental test of our formulation.Comment: 10 pages, 2 figures. Several changes were made on the text. One extra example was include