295 research outputs found
The reality of media freedom in Swaziland under the new constitutional dispensation
No full textThe study concludes that there is still lack of media freedom in Swaziland under the new constitutional dispensation. Its significant finding is that the lack of media freedom is a consequence of constitutional, legal and extra-legal constraints
Raw and real: How travel influencers package the nation.
No full textThis paper delineates how Indian travel influencers construct and morph the tourist gaze of the domestic viewer. The author argues that through Instagram reels, YouTube shorts and vlogs, domestic travel Social Media Influencers (SMIs) propagate a skewed understanding of the nation—one that necessarily (a) claims to offer a glimpse of unseen and authentic India that exists outside of where the viewer resides; (b) can be discovered only in remote, interior parts of the country such as towns/villages or larger neglected, peripheral regions such as the North-East; (c) consists of people who are uni-dimensionally kind, generous and happy—living in peace and harmony with no conflict. Anything that does not fit this paradigm is edited out and not presented to the viewers. Thereby these SMIs articulate an imaginative geography of the nation that not only echoes their ideology but frequently melds to become a
constitutive component of the very spaces they imagine.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/177343/1/22-Chaudhary-Travel-Social Media and Society in India Proceedings-125-132-10.73027940.pdfSEL
Resin and steel-reinforced resin used as injection materials in bolted connections
No full textInjection bolts are bolts in which the cavity produced by the clearance between the bolt and the wall of the hole is completely filled up with a two-component resin. Filling of the clearance is carried out through a small hole in the head of the bolt. After injection and complete curing, the connection is slip resistant. Recently the injection material, typically an epoxy resin, was modified at TU Delft by adding steel shots (spherical particles) to mitigate the effects of resin compliance in the shear connection of reusable composite (steel-concrete) structures. Experimental compressive material tests on unconfined/confined resin and steel-reinforced resin are evaluated in this chapter. The uniaxial model which combines damage mechanics and the Ramberg-Osgood relationship is proposed to describe the uniaxial compressive behavior of resin and steel-reinforced resin. First-order numerical homogenization is employed as a high-fidelity model, where a combined nonlinear isotropic/kinematic cyclic hardening model is employed to define the steel plasticity, the linear Drucker-Prager plastic criterion was used to simulate resin damage, and the cohesive surfaces reflecting the relationship between traction and displacement at the interface. The linear Drucker-Prager plastic model is used as a low-fidelity model.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Steel & Composite Structure
Mechanics of biopolymer networks, stimuli responsive particle suspensions, and their combinations
No full textThe key aim of this thesis is to demonstrate new paradigms in designing stiffness changing soft materials. The systems developed and studied in this work have salient and unprecedented features such as (1) the ability to controllably stiffen up to 100 times (10,000 %) when exposed to an external stimulus of temperature or magnetic field, (2) the ability to uncontrollably assemble into a ultra-soft hydrogel by undergoing 10,000 fold volume expansion within 0.4 s, and (3) transformation from a repulsive colloidal glassy state to a particulate gel thus undergoing change in the dynamics and mechanical properties. With a combination of rigorous experiments and mathematical models, this thesis offers novel ways to achieve functionality in soft materials and may have numerous applications in the fields of soft robotics, defense, and direct-write additive manufacturing.
In part one of this thesis, a naturally produced biomaterial, hagfish slime is studied to understand its design principles. Hagfish slime is a unique predator defense material containing a network of long fibrous threads each 10 -15 cm in length. Hagfish releases the threads in a condensed coiled state known as skeins (∼ 100 µm), which must unravel within a fraction of a second and form a soft hydrogel to thwart a predator attack. The mechanisms of how the hagfish controls the unraveling rates, and the properties of the resulting gel are not well understood. The combined experimental and theoretical approach adopted in this thesis address these questions. First, the hypothesis that the viscous hydrodynamics may be responsible for the rapid unravelling rates is considered, and the scenario of a single skein unspooling as the fiber peels away due to viscous drag is discussed. As a result, its is shown that under reasonable physiological conditions viscous-drag-induced unravelling can occur within a few hundred milliseconds, comparable with the physiological time scales. Subsequently, through the rheological study on slime networks it is shown that key rheological and structural features of hagfish slime are insensitive to its concentration, in spite of the uncontrolled gelation process, and this peculiar characteristic may be vital for its physiological use.
In part two, the linear and nonlinear rheology of a model system of soft microgel suspensions is investigated. The interaction pair-potential between the microgel is temperature-dependent. By increasing concentration of the suspension, a transition from a viscous liquid to an entropic glass to a soft jammed state at low temperatures where the microgels interact via a repulsive potential. Increasing the temperature of the suspension beyond the Lower Critical Solution Temperature [LCST], introduces additional attractive interactions, and results in the formation of particulate gels. The competition between repulsive and attractive interactions gives a rich temperature-dependent rheological response that is also concentration-dependent. An integrated experimental and quantitative theoretical approach is presented to understand the key linear and nonlinear of the suspensions in various regimes.
In part three, two novel soft composite systems capable of unprecedented change in their mechanical properties in response to magnetic and thermal excitation are developed. The composites were formed by integrating stimuli-responsive particles (thermoresponsive microgels and magnetic particles) into the strain stiffening network of biopolymer fibrin. The interactions between the stimuli-responsive particles and biopolymer mesh is hypothesized to induces local stresses in the mesh, which inherently stiffens under the stress owing to its semiflexible nature. This helps achieve a higher sensitivity to the external field in the fabricated composites compared to the traditional flexible-polymer matrix of composite systems. Phenomenological models are developed that quantify this hypothesis, and the derived predictions are qualitatively consistent with the experimental data. This approach of using composites based on semiflexible polymers with strong inherent nonlinearity offers a promising method for developing functional materials with actively tunable mechanical propertiesSubmission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2021-08-01The student, Gaurav Chaudhary, accepted the attached license on 2019-07-12 at 10:20.The student, Gaurav Chaudhary, submitted this Dissertation for approval on 2019-07-12 at 10:21.This Dissertation was approved for publication on 2019-07-12 at 14:32.DSpace SAF Submission Ingestion Package generated from Vireo submission #14296 on 2019-11-26 at 14:04:03Made available in DSpace on 2019-11-26T20:59:48Z (GMT). No. of bitstreams: 2
CHAUDHARY-DISSERTATION-2019.pdf: 55821292 bytes, checksum: 4de68df7543cc6616e21c2fdbc7be7f3 (MD5)
LICENSE.txt: 4213 bytes, checksum: 9b6722110899830fd960dae7c4e98fd1 (MD5)
Previous issue date: 2019-07-12Embargo set by: Seth Robbins for item 113090
Lift date: 2021-11-26T20:59:54Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 113090 on 2021-11-27T10:15:27Z
Development of metal contacts with screen printing for n+ polysilicon/SiO𝑥 passivated silicon solar cells
No full textThe continued reliance on fossil fuels to satisfy the world energy demand is leading to climate change, accelerating the melting of polar ice shelf, and is dealing irreversible damage to the flora and fauna of earth, to name few of the adverse effects from fossil fuel utilisation. In addition to not being renewable, fossil-fuel resources are also limited. Therefore these resources cannot meet the energy demand at some point in future. The most plausible way is to utilise renewable sources of energy to meet the increasing demand of energy. The Sun, our closest star is the answer to this demand. Utilising the abundant solar radiation arriving at earth to generate electricity is a great way. A photovoltaic (PV) solar cell can achieve this by converting the incident sunlight directly to electricity.....<br/
Predicting drum beats from high-density Brain Rhythms
No full textEntrainment is a phenomenon of phase or temporal matching of one system with that of another system. Human neural activity has been shown to resonate with external auditory stimuli. When we enjoy a piece of music, there is a resonance of brain responses with auditory signals. The crux of music cognition is based on this resonance of musical frequencies with intrinsic neural frequencies. It has also been demonstrated that the neural activities are synchronized across participants while listening to music, shown by high inter-subject correlation. In this work, we use this fact to predict the drumbeat a participant listens to based on their EEG response to the drumbeat. We also tested whether we could train on a smaller dataset and test with the rest of the dataset. We generated a frequency∗channel plot and fed it to a CNN model to predict drumbeat with a classification accuracy of 97% for 60-20-20 (train-dev-test) data split protocol and 94% accuracy for 20-20-60 data split. We also got 100% classification accuracy for predicting participants for both the data split protocols. Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Design Aesthetic
Microstructural evolutions, phase transformations and hard magnetic properties in polycrystalline Ce–Co–Fe–Cu alloys Author links open overlay panel
No full textThis work focuses on systematic studies of Ce–Co based 1:5 permanent magnet alloys of CeCo4.4-xFexCu0.6 and CeCo3.9-xFexCu1.2 (x = 0, 0.3, 0.6, 0.9, 1.2, 1.8) by varying Co:Fe. The overarching aim of this manuscript is to elucidate the hard-magnetic properties through a better understanding of phase formation by the structural, microstructural, and magnetic properties in these materials. Improved mutual solubility of Fe in the 1:5 phase has been observed with an extended homogeneity range by Cu substitution. For both composition series, Fe contents of x ≤ 0.6 show a homogeneous microstructure with a single 1:5 phase and good magnetic properties. The composition region 0.6 < x ≤ 0.9 appears to be near the boundary of solubility and evolution of other phases. At x = 1.8, it is found that the homogeneous 1:5 phase and magnetic hardness deteriorated due to the evolution of secondary phases such as 2:17, 2:7, and Fe–Co. The addition of Fe improved both the magnetization and Curie temperature via increased effective exchange interactions, while an increase in Cu content enhanced coercivity.This is a manuscript of an article published as Gandha, Kinjal, Rakesh P. Chaudhary, Matthew J. Kramer, Ryan T. Ott, Durga Paudyal, and I. C. Nlebedim. "Microstructural evolutions, phase transformations and hard magnetic properties in polycrystalline Ce–Co–Fe–Cu alloys." Materials Chemistry and Physics 286 (2022): 126179.
DOI: 10.1016/j.matchemphys.2022.126179.
Copyright 2022 Elsevier B.V.
Posted with permission.
DOE Contract Number(s): AC02-07CH11358
Analysing the feasibility of financial rewards for mentors engaged in entrepreneurial mentoring
No full textNeurofibroma of the maxillary antrum: A rare case
No full textNeurofibromas are benign tumors of peripheral nerve tissue, frequently associated with neurofibromatosis type 1. Their isolated occurrence in the maxillary antrum is rare, with only 6 cases described in the English literature to the best of our knowledge. Primary neurogenic tumors in the maxillary sinus are unusual entities. The majority of the reported cases that have dealt with neurilemmomas and isolated neurofibromas are extremely rare. Here, a case of neurofibroma of the maxillary sinus. We present the case of a 60-year-old female patient with the chief complain of growth in the upper right back region of the jaw, which was preceded by exfoliation of teeth in the same region 1 month back
- …
