Early Online (Volume - 4 | Issue - 7) at IgMin Research

This paper reviews requirements for water supply rate for life support of human crews on deep space missions such as Mars, and approaches to provide a reliable water supply. The literature on the required water supply flow rate to support human crews in deep-space missions is sparse. Estimates were generated in an era where saving mass was critical, and the allocations were skimpy. Here, we provide updated estimates of the suggested water supply flow rate to support human crews on deep-space missions in an era when mass in deep space is fa...r more affordable. Water a higher flow rate of water to the crew than had previously been suggested.It was widely believed that water recycling systems are necessary to reduce mission mass in the era of high launch costs. However, the reliability of recycling technology is inadequate, as evidenced by experience on the International Space Station. Use of spares to replace subsystems that fail was proposed to greatly improve reliability, and that works well theoretically as shown by probabilistic analysis, but the logistics of validation and implementation are problematic. Mars mission water system designs should focus on maximizing reliability to provide crew safety. The earlier design goal of reducing launch mass by increasing water recycling closure is now less relevant because of the recent great reduction in launch cost. Reliable water supply for life support can be provided by some combination of stored water from Earth, recycling of wastewater, or use of indigenous Mars water. There is an implicit three-way trade between performance, cost, and risk depending on the mission design.A simplified human Mars mission that uses the Starship can bring water from Earth, thus avoiding the two difficult challenges of recycling and processing indigenous Mars water, achieving high safety and reliability, and landing at an equatorial site. More ambitious human Mars missions might need recycling and/or indigenous Mars water, but they should always bring survival-level water from Earth. If indigenous water is required, that limits landing sites to around 40°N or higher altitudes.Bringing water from Earth is the best way to supply crew requirements for limited missions likely to be the first human landings on Mars. For futuristic missions of great extent, either recycling or use of indigenous water from Mars would be needed. Both methods involve significant technical, timeline, and fiscal challenges. In any mission, as a minimum, bringing a survival level of water from Earth is strongly recommended.Read more

This paper presents a high-fidelity multiphysics numerical framework for simulating the acoustic performance of circumaural headphones coupled to a generic artificial ear, spanning the full audible frequency range from 20 Hz to 20 kHz. The proposed model integrates five essential physical phenomena: (1) pressure acoustics in air domains governed by the frequency-domain wave equation, (2) poroelastic wave propagation in foam cushion materials based on Biot's theory, (3) lumped-parameter electrodynamic driver modeling using Thiele-Small parameter...s, (4) frequency-dependent impedance characterization of perforated plates and acoustic meshes, and (5) physiological boundary conditions representing human skin and eardrum impedance. The computational domain incorporates a realistic 3D-scanned pinna geometry, an idealized ear canal (7.5 mm diameter, 19.8 mm length), and a headphone housing with internal acoustic chambers. Interior Perforated Plate conditions capture the acoustic resistance and mass effects of ventilation meshes, while Perfectly Matched Layers (PMLs) ensure artifact-free free-field radiation. Key findings reveal the frequency-dependent acoustic coupling mechanisms, demonstrating that the foam cushion acts as a low-pass filter at frequencies below 200 Hz, while perforated plates dominate the mid-to-high frequency response (200-2000 Hz and 2-20 kHz, respectively). The ear canal resonance at 3-4 kHz is successfully captured, with the coarse mesh model (28 GB RAM) showing excellent agreement with the fine mesh reference (100 GB RAM) up to 5 kHz, beyond which mesh resolution becomes critical. The study provides quantitative validation of SPL distribution on the pinna surface and at the eardrum, offering actionable insights for headphone design optimization. Computational trade-offs between accuracy and resource requirements are systematically evaluated, with recommendations for mesh sizing, solver configuration, and PML implementation. The validated framework establishes a robust digital twin methodology for virtual prototyping, parametric studies, and performance prediction in the audio industry.Read more

This paper proposes a novel deep learning-based framework for the multi-class prediction analysis of 3-D objects through the application of phase-only digital holographic data obtained via the phase-shifting approach. The dataset utilised in this study comprises seven distinct 3-D object pairings: M-L, D-L, C-N, A-I, D-S, C-S, and H-R, all represented by phase-only holographic images that maintain crucial spatial and depth information. The digital holograms were formed using programmatically generated synthetic 3-D objects and further numerical...ly processed to create 2-D phase images that served as inputs to the prediction task. A custom convolutional neural network (CNN) architecture, along with a modified AlexNet architecture, was employed to simultaneously predict multiple continuous attributes associated with the 3-D objects from their respective phase-only inputs. Regression (Prediction) task model performance was evaluated using mean squared error (MSE), mean absolute error (MAE), and R2 score metrics, demonstrating the ability to perform multi-class prediction with high accuracy and robustness, while also being computationally efficient. The CNN has achieved better regression performance compared to AlexNet in terms of MSE, MAE, and R2 score values. The use of deep learning in this manner thus provides a scalable method of analysing 3-D objects using holographic imaging techniques, moving away from previous binary regression techniques and the limitations of traditional machine learning approaches towards richer predictions of multiple associated attributes.Read more

Micromobility has emerged as an important element of sustainable urban transport, offering an effective solution for first- and last-mile connectivity. Despite the growing adoption of shared electric vehicles, many existing fleet deployment and routing methods continue to prioritise minimising travel distance while paying limited attention to the impact of road topography on energy consumption. This omission is particularly relevant in cities with varying terrain, where elevation changes can significantly affect battery usage and overall operat...ional efficiency. This paper introduces a physics-informed optimisation framework that incorporates terrain-related energy demand into micromobility fleet deployment. Instead of relying solely on travel distance, the proposed approach estimates the energy required for vehicle movement by accounting for rolling resistance, aerodynamic drag, gravitational effects caused by road slopes, and energy recovery through regenerative braking on downhill sections. These energy calculations are embedded within a graph-based optimisation model whose objective is to identify routes with the lowest total energy consumption. To assess the effectiveness of the proposed methodology, a case study was conducted using selected road segments from the Vilnius street network that represent different topographical characteristics. The simulation results indicate that road elevation has a substantial influence on vehicle energy requirements. They also reveal that the shortest path does not always correspond to the most energy-efficient one. In several scenarios, longer routes consumed less energy because of more favourable elevation profiles and the additional benefits provided by regenerative braking. Compared with traditional distance-based routing strategies, the proposed framework offers a more accurate representation of real-world energy consumption, leading to better-informed fleet deployment decisions. The methodology is suitable for integration into real-time fleet management systems and smart city platforms, where it can contribute to lower energy consumption, improved battery utilisation, and more sustainable operation of shared micromobility services.Read more

This paper reports on a case study in radiation protection, revealing that the statistical phenomena observed in the dose distribution of workers under dose reduction management exhibit an intriguing new probability distribution. This distribution unifies the lognormal and the normal distributions—previously considered distinct—by replacing the upper tail of the former with that of the latter. It is adjusted by the parameter ρ from the former (ρ → 0) to the latter ( → ∞), allowing for an accurate analysis of ...the statistical phenomena existing between the two. This is the “hybrid lognormal (HLN) distribution,” defined by the hybrid transformation hyb(ρX) = ln X + X, which replaces the logarithmic transformation ln X. The stimulus η = Δhyb(ρX) yields the increment ΔX = ηX/(1+ρX). Interpreting the numerator as the risk increment and the denominator as the risk reduction (achieved through feedback control), this equation represents the simplest risk management principle. The hybrid transformation is visualized as a hybrid scale (HS) consisting of a logarithmic scale and a linear scale, demonstrating its utility in evaluating the effectiveness of risk management. We discuss the background of this case study, the generation mechanism and statistical characteristics of the HLN distribution, application examples, as well as its position within the context of probability distributions and the applicability of the hybrid scale to case studies.Read more

This paper continues the fourth instalment of a series published in ArtyHum, No. 91: “A Brief Western History of Furniture Design (Part 4): The Indo-Ibero-American Chair.” It draws on theoretical concepts developed there and connects them to the doctoral dissertation of Dr Ibar Federico Anderson, industrial designer (National University of La Plata), and to the master’s thesis of architect Gastón Eduardo Girod (University of Buenos Aires), completed at the University of Palermo. The present study revisits concepts first... articulated by Anderson in ArtyHum Nos. 71 and 74, together with concepts co-authored by Anderson and Girod in previous instalments published in ArtyHum Nos. 84, 85, and 90. Taken together, these five research articles — which we refer to collectively as a Brief Western History of Furniture, and of the chair in particular — have allowed us to draw parallels between the Old Continent (Europe) and the New (America), tracing a line from the Iberian Peninsula (chiefly Spain) and its American colonies to the development of Latin American material culture. Across these publications, several theoretical concepts have been developed, several of which are resumed and deepened here, while new avenues for theoretical and methodological inquiry are opened. This article builds specifically on the previous instalment, “A Brief Western History of Furniture Design (Part 4): The Indo-Ibero-American Chair” (ArtyHum No. 91), to distil the essential character of the American chair itself. In doing so, it argues that the American chair should be read not as a derivative repetition of European stylistic categories but as the dialectical synthesis of a longer syncretic process — pre-Columbian, colonial, and Creole — and it makes explicit, for the first time in this series, the structural, gendered, and decolonial dimensions of that synthesis.Read more