56 research outputs found
Advancing public health: enabling culture-fair and education-independent automated cognitive assessment in low- and middle-income countries
No full textCITATION Garuma D, Lamba D, Abessa TG and Bonnechère B () Advancing public health: enabling culture-fair and education-independent automated cognitive assessment in low-and middle-income countries.The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study was supported by the NASCERE program
Design of inflatable lunar structure
No full textNASA and other space agencies are now looking to create a lunar settlement for the continued exploration of Moon and beyond. The most challenging aspect of a lunar settlement is its construction, and the weight and size of building materials brought from Earth. In-Situ Resource Utilization (ISRU) and inflatable structures are considered to be the most preferred way for the fabrication of a lunar settlement because they minimize weight and size. The use and performance of inflatables and flexible structures in space applications have been increased in the recent past due to the technological advancements in materials technology. So, we propose the concept of two-tier semi-rigid inflatable structure where the base is built with the help of autonomous robots using ISRU, and the main inflatable structure is manufactured on Earth and inflated on the lunar surface. Also, magnesium is proposed as the base material as it is the most abundantly available structural-strength material in lunar environment, and it is relatively easy to machine. A hemispherical inflatable structure placed on top of a cylindrical base with regolith shielding around the structure is considered as a possible lunar design as well as the test prototype. A static analysis is first conducted on the proposed design using ANSYS, and the stress values are order-of-magnitude verified with simple calculations that prove the possibility of the material and model. Also, an order-of-magnitude analysis is conducted on meteoroid impact loads where we estimate the maximum size of meteoroid that our structure can sustain. As future work, we suggest the framework known as Performance Based Engineering. We had spent some time attempting to use this framework for a simplified lunar structural analysis. However, large data gaps precluded significant progress. But we include it as one of our future research topics.M.S.Includes bibliographical referencesby Dheeraj Kumar Kaj
Development of two-way coupled CFD – DEM model for top spray fluid bed granulator using star CCM+
No full textA two-way coupled Computational fluid dynamics (CFD) – Discrete element method (DEM) model is developed using STAR-CCM+ for a top spray fluid bed granulator to study the effects of process parameters such as inlet air flow rate, temperature on the particle dynamics and the residence time in the spray zone. The framework relies on coupled CFD–DEM simulations to provide particle-level mechanistic information such as collision frequencies, particle flux and residence time of the particles in the spray zone. Particles of diameter 1 mm (Group B particles according to Geldart’s classification of powders) are considered for model development. To reduce the computational load, the particles are scaled by keeping the non-dimensional terms Archimedes, Reynolds’s numbers and the minimum fluidization velocity of the system constant. Passive scalar model is also used for Lagrangian phase to track the residence time of the particles within the spray zone. This model accurately predicts the effect of process parameters (inlet air flow rate, temperature) on the particle dynamics and the particle residence time inside the spray zone. This mechanistic data can be used in Population balance models (PBM) to model the rate processes such as agglomeration, breakage and consolidation.M.S.Includes bibliographical referencesby Dheeraj Reddy Devarampall
Meotipa andamanensis Tikader 1977, new combination
No full textMeotipa andamanensis (Tikader, 1977) new combination Argyrodes andamanensis Tikader, 1977: 170, f.7A–B (Df) Holotype (not eXamined): Female, ZSI, Chiriatapu, South Andaman, India. Original description and illustration of Argyrodes andamanensis mentioned black FS on legs and abdomen, shape of abdomen and colour pattern of white and brown patches (Tikader 1977). These characters as well as the illustrations provided by the author match closely with the type species M. picturata and thus leaves no doubt that A. andamanensis should be transferred to the genus Meotipa following the current diagnosis by Deeleman- Reinhold (2009). Therefore we propose the new combination here as Meotipa andamanensis (Tikader, 1977) n. comb. Distribution. Known from Chiriatapu, South Andaman, India.Published as part of Kulkarni, Siddharth, Vartak, Atul, Deshpande, Vishwas & Halali, Dheeraj, 2017, The spiny theridiid genus Meotipa Simon, 1895 in India, with description of a strange new species with translucent abdomen and a phylogenetic analysis about the genus placement (Araneae, Theridiidae), pp. 504-520 in Zootaxa 4291 (3) on pages 515-516, DOI: 10.11646/zootaxa.4291.3.4, http://zenodo.org/record/82765
Effect of virtual reality-based upper limb training on activity of daily living and quality of life among stroke survivors: a systematic review and meta-analysis
No full textBackground Stroke is a leading cause of disability worldwide, significantly impairing upper limb (UL) function and reducing patients' ability to perform activities of daily living (ADL) and quality of life (QoL). Virtual reality (VR) has emerged as a promising tool; for UL rehabilitation, offering immersive and engaging environments for motor recovery. However, the effectiveness of VR, its integration with conventional therapy, and their efficacy across different stroke recovery stages remain unclear. Therefore, this systematic review and meta-analysis aimed to evaluate the effectiveness of VR-based UL interventions in improving ADL and QoL among stroke survivors. Method This study adhered to PRISMA guidelines and was registered on PROSPERO (CRD42023426256). A systematic search of PubMed, Scopus, and Web of Science identified randomized controlled trials (RCTs) published in English. Inclusion criteria focused on studies using immersive VR (IVR) and non-immersive VR (NIVR) interventions to assess ADL and QoL in stroke survivors. Data extraction and quality assessment were performed independently by two reviewers using the PEDro scale to assess quality. Meta-analyses were conducted to determine the efficacy. Subgroup analyses were performed to compare IVR and NIVR, VR combined with conventional therapy versus standalone VR, and potential differences between stroke recovery stages. Result Thirty RCTs, representing 1,661 participants, were included. Overall, VR interventions significantly improved ADL (SMD = 0.27, 95% CI [0.11; 0.43], p < 0.001) and QoL (SMD = 0.94 [0.09; 1.79], p = 0.035) compared to conventional therapy. IVR demonstrated superior outcomes for ADL compared to NIVR (SMD = 0.54 [0.13; 0.95] Vs. 0.17 [0.02; 0.36], p = 0.03). Subacute stroke survivors exhibited the most significant gains in ADL (SMD = 0.52 [0.16; 0.88], p = 0.004), compared to chronic (SMD = 0.05 [-0.36; 0.46]) or acute patients (SMD = 0.08 [-0.11; 0.27]). Conclusion VR interventions, particularly IVR and VR combined with conventional therapy, significantly enhance ADL and QoL in stroke survivors with moderate certainty of evidence. These findings underscore the value of VR in rehabilitation, especially during the subacute phase, but highlight the need for further research into long-term effects and implementation in low-resource settings.Funding
The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study was supported by the NASCERE program.
Acknowledgements
The authors would like to express appreciation to all the NASCERE project coordinators and their teams, at Ghent University, Hasselt University and Jimma University, for the funding and other facilities
Modelling of Metastable Equilibrium State using PRB Principles
No full textThis thesis proposes the introduction of a metastable equilibrium state in a viscoelastic pre-curved beam. Generally, metamaterials with bistable unit cells need an external application of force to restore, leading to the contemplation of possible structures with self restorable behaviour. Such restorable nature is associated with metastable equilibrium, which is a time-dependent equilibrium state. The objective of the topic is to build a proof of concept for metastability in a pre-curved beam and identify the influence of geometric parameters on metastability. In the course of the thesis, various models of bistable designs are classified. A feasible bistable mechanism was selected, and the metastable nature is introduced through viscoelasticity. In this thesis, an analytical model is formulated by combining an equivalent Pseudo Rigid Body (PRB) model of the pre-curved beam (modelling the beam's compliance) with Standard Linear Solid (SLS) model (modelling the beam’s viscoelasticity). Prototypes are manufactured by using FDM printing of TPU material. Experimental studies are performed for the evaluation of material properties and testing for metastability in pre-curved beams with various shape factors. The results of experimental studies proved the possibility of metastable equilibrium in viscoelastic pre-curved beams. Later, discussions are offered to improve the predictability of metastability in pre-curved beams and the scope for future studies
Intent-Based Networking for Non-programmable Networks
No full textIntent-based Networking (IBN) is one of the hot topics of research in the modern field of networking. Abstracting the complexity of network management away from the network operator through automation is the cornerstone of the IBN concept. However, a lot of current research on intent-based networking is concentrated towards programmable software defined networks (SDN), rather than traditional non-programmable network devices which still hold a large market share in modern networks. Moreover, when it comes to traditional network devices, network validation becomes very crucial as it needs a endoragnostic environment to evaluate the network. This thesis studies the important aspects necessary for IBN adaptation for legacy devices and provides a solution for adaptation into modern networks, while being vendor-agnostic. Based on the design, the results obtained from the proofs-of-concept are then analyzed and concluded upon, ending by elucidating avenues of future work.Electrical Engineering | Embedded System
Hall coefficient measurement for residual stress assessment in precipitation hardened IN718 nickel-base superalloy
No full textWe investigated the feasibility of residual stress assessment based on Hall coefficient measurements in precipitation hardened IN718 nickel-base superalloy. As a first step, we studied the influence of microstructural variations on the magnetogalvanic properties of IN718 nickel-base superalloy. We found that the Hall coefficient of IN718 increases from ≈8.1×10-11 m3 /C in its fully annealed state of 15 HRC Rockwell hardness to ≈9.8×10-11 m3 /C in its fully hardened state of 45 HRC. Second, we studied the influence of cold work, i.e., plastic deformation at room temperature, and found that cold work had negligible effect on the Hall coefficient of fully annealed IN718, but significantly reduced it in the hardened state of the material. For example, measurements conducted on fully hardened IN718 specimens showed that the Hall coefficient decreased more or less linearly with cold work from its peak value of ≈9.8×10-11 m3 /C in its intact state to ≈9.3×10-11 m3 /C in its most deformed state of 22% plastic strain. Third, we studied the influence of applied stress, and found that elastic strain significantly increases the Hall coefficient of IN718 regardless of the state of hardening. The relative sensitivity of the Hall coefficient to elastic strain was measured as a unitless gauge factor F that is defined as the ratio of the relative change of the Hall coefficient ΔRH/RH divided by the axial strain ε = σ/E, where σ is the applied uniaxial stress and E is the Young’s modulus of the material, i.e., ΔRH = RH (1 + F ε). We determined that the galvanomagnetic gauge factor of IN718 is F ≈ 2.5-3 depending on the hardness level. Besides the fairly high value of the gauge factor, it is important that it is positive, which means that compressive stress in surface-treated components decreases the Hall coefficient in a similar way as plastic deformation does, therefore the unfortunate cancellation that occurs in fully hardened IN718 in the case of electric conductivity measurements will not happen in this case.</p
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