77 research outputs found
Different quantities of manganese oxide nanoparticles incorporated feed on the growth and haematological traits of common carp Cyprinus carpio var. communis
No full textIn recent times, nanoparticles have been used as raw ingredients for biofertilizers, mineral supplements in animal feed, and pharmaceuticals. Manganese plays a vital role in enhancing fish\u27s growth and biological function. The present research work aimed to analyze the various quantities of manganese oxide nanoparticles on common carp growth and its haematological traits. Synthesized manganese oxide (Mn3O4) nanoparticles were illustrated using UV-visible Spectroscopy (UV-Vis), Scanning Electron Microscope (SEM), Energy Dispersive X–Ray Spectroscopy (EDAX), X–Ray Diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR). Six different feeds were prepared by incorporating different quantities of manganese oxide nanoparticles (Feed I (control-0mg), Feed II(3mg/100g), Feed III(6mg/100g), Feed IV(9mg/100g), Feed V(12mg/100g), and Feed VI(15mg/100g)) with common ingredients such as groundnut oil cake, fish meal, tapioca flour, and wheat flour. On the completion of 21 days, feed utilization and haematological characteristics of Common carp were assessed. The UV-Vis showed that manganese oxide nanoparticles exhibit strong adsorption peaks at 220nm. SEM image observed at the wavelength range from 9.22 nm to 9.35 nm. The size of the particles was in the 45-55 nm range. The EDAX spectrum recorded two peaks between 0.40 and 6 kev. The XRD graph shows that the diffraction peaks are indexed as 103, 004, 213, 204, 303, and 215. FT-IR spectrum measured at the wavelength range from 500-4000cm-1. Most of the growth parameters and haematological parameters were higher in feed III, containing 6mg of Manganese oxide nanoparticles. Therefore, results show that manganese oxide incorporated feed enhances the growth and haematological traits in common carp compared to control feed.
Validation of Large Area Capacitive Sensors for Impact Damage Assessment
No full textImpacts in fiber-reinforced polymer matrix composites can severely inhibit their functionality and prematurely lead to the composite’s failure. This research focuses on determining the efficacy of a novel capacitive sensor, termed as the Soft Elastomeric Capacitor or SEC, to monitor the magnitude of out-of-plane deformations in composites. This work forwards the development of a sensing skin that can be used as an in situ monitoring tool for composites. The capacitive sensor can be made to arbitrary sizes and geometries. The sensor is composed of an elastomer composite that measures strains experienced by the material it is bonded to. The structure of the sensor, fabricated to function as a parallel plate capacitor, responds to impacts by transducing strains into a measurable change in capacitance. In this work, the SECs are deployed on randomly oriented fiberglass-reinforced plates with a polyester resin matrix. The material is impacted at various energy levels until the monitored
composite material reaches its yielding point. The behavior of the sensor in impact detection applications below the proof resilience shows little to no change in the capacitance of the sensor. As the impacts surpass this yielding point, the sensor responds linearly with induced change in the area. The sensor performed within the expectations of the proposed model and demonstrated the efficacy of the proposed large-area sensor as a damage quantification tool in the structural health monitoring of composites.This is an accepted manuscript of an article published as Vereen, Alexander Brennan, Austin Downey, Subramani Sockalingam, and Simon Laflamme. "Validation of Large Area Capacitive Sensors for Impact Damage Assessment." Measurement Science and Technology (2023). doi:https://doi.org/10.1088/1361-6501/ad0954. This Accepted Manuscript is © 2023 The Author(s). This Accepted Manuscript is available for reuse under a CC BY 4.0
Optimally sparse and adaptive far-field sampling and pattern reconstruction: Approach for faster calibration of antenna system using compressed sensing
No full textRadiation pattern measurements is a critical step in characterizing antennas before they are used in any system for a specific application. To identify any defects or to acquire the true radiation characteristics of the antenna under test, densely sampled measurements are desired. However, this results in a time and cost expensive measurement process. Compressed sensing allows accurate reconstruction of radiation patterns using a reduced number of measurements. To ensure exact recovery, it is necessary to select an optimal sampling strategy as well as an effective reconstruction method. In this thesis, the discrete Fourier transform and spherical harmonic expansion of the electric field are used to obtain a sparse representation of radiation patterns. As a variation from the basis pursuit optimization problem which is widely used in compressed sensing for antenna measurements, a sparsity enhancing weighted l1-norm minimization problem is considered. The weights are determined from prior information on antenna from electromagnetic simulations. The proposed method, after investigation with various antennas and comparison with existing benchmark results in a further reduction of number of required measurements. A near-optimal sampling technique is adopted to acquire measurement in an incoherent manner for exact recovery of the pattern. The performance of the method has been evaluated using error metrics specific to important parameters of the radiation pattern such as the gain, peak side lobe level and half power beam width. Radiation patterns with non-idealities and distortions have also been recovered with high accuracy from a small number of measurements using the proposed method.Electrical Engineerin
Goblet cell-intrinsic colonic defense
No full textThe intestine is constantly exposed to billions of commensal microbes as well as
pathogens and opportunistic organisms. Protection of the epithelium depends on the
mucus barrier, produced by goblet cells (GCs), which separates bacteria from host
tissue while maintaining tolerance to the microbiota. Several studies have established
the importance of Muc2 and the inner and outer mucus layers in maintaining intestinal
homeostasis, but multiple key questions remained unresolved in our understanding of
mucus associated protection to bacterial infections. It has been unclear how
specialized GC subsets mature after birth, how pathogens selectively undermine these
protective cells, and how environmental factors such as diet destabilize mucus
integrity to permit disease.
This thesis addresses these gaps by defining the developmental, functional, and
pathological dynamics of distinct GC populations. We show that postnatal maturation
of sentinel goblet cells (senGCs) is driven by microbial colonization, requiring Duox2
signaling to enable rapid, MAMPs-dependent mucus secretion. In parallel,
noncanonical GCs contribute unique proteins to the mucus proteome reinforcing the
structural and antimicrobial properties of the inner mucus layer. Building on this, we
demonstrate that during Citrobacter rodentium infection, the pathogen destabilizes
the inner mucus layer and potentially exploits the type III secretion system effector
EspF to selectively deplete Spdef-dependent intercrypt GCs (icGCs). Loss of these
cells dismantle the intercrypt mucus network, creating niches for bacterial persistence
that cannot be compensated by crypt plume mucus alone. Our study further suggests
that senGCs are important drivers of crypt-specific secondary defense during
infection. They dynamically expand into deep crypts, sustain baseline mucus
secretion, and coordinate Th17 responses. Their absence leads to accelerated GC loss,
sex-specific susceptibility, and early indications of barrier compromise. Finally, we
reveal that short-term exposure to a Western-style diet disrupts jejunal mucus integrity
through increased Tgm2-mediated cross-linking of Muc2, preventing proper mucus
expansion and enabling ectopic colonization of the small intestine by C. rodentium.
Together, these findings update our understanding of the intestinal mucus barrier as a
dynamic and adaptable system shaped by microbial signals, dietary factors, and
contributions from specialized GC subsets. By uncovering how senGCs and icGCs
preserve barrier integrity, and how pathogens and diet exploit their vulnerabilities,
this work advances mechanistic understanding of how the intestinal GCs and the
secreted mucus barriers preserve homeostasis and how their functional ablation
creates vulnerabilities during infection
Refractive index engineering of poly (vinyl alcohol)/Li2ZnO2 nanocomposites: Effect of filler content and annealing temperature
No full textDynamic Era of Fijian Writing
No full textIn an article published recently (Fiji Times 04/08/2017) Dr. Joseph Veramu, a policy analyst consultant argues that “apart from the prolific internationally renowned writer Dr. Satendra Nandan, the Fijian writing scene appears dormant”. It might be prudent to imply that the writer is not aware of the number of writers that have emerged in the last few decades. Then again the article is quite contradicting when the author concludes “it appears that a lot of creative works are being produced locally”. In fact, there is a new vigour in Fijian writing as evident from an online publication New Fijian Writing (http://fijianstudies.net/2014-21/) which has significant mix of established and new writers, among them 10 old writers such as Subramani, Teresia Teiawa, Senoa Smiles, Satish Rai, Mohit Prasad, Larry Thomas, Joini Madraiwiwi, Satendra Nandan, Sudesh Mishra, and Brij Lal, with more than 15 new writers such as Bhim Singh, Satvick Dass, Anna Rarasea, Afsana Anzeg, Pauline Reyland, Praveen Chandra, Pranesh Prasad, Sakiusa Viaviaturaga, Seruwaia Vukivou, Anurag Subramani, Izaz Khan, Kelera Tuvou, Shyamendra Shrama and Harish Sharma. The notion of writing in Fiji has always been an ongoing pursuit and there seems to be a thrust in writing as more writers have joined in to continue the legacy
Physically secure and fog-enabled lightweight authentication scheme for WBAN
No full textAbstract Wireless Body Area Networks (WBANs) are vital for healthcare, fitness monitoring, and remote patient care by means of combining sensors and wearable technologies for data collection and transmission. However, ensuring secure communication in WBANs remains a critical challenge and is generally insecure against the manipulation of data, breaches of privacy, and unauthorized access. Current authentication methods are vulnerable to security risks and have a significant computational burden. The above-said shortcomings are addressed by proposing a lightweight, physically secure, fog-enabled authentication scheme that guarantees data privacy and system resilience by integrating Physically Unclonable Functions ( ) and Fog Computing. This approach involves two phases: WBAN node registration and secure anonymous authentication. The proposed system incurs a reduction in computational overhead of 64.33% and communication overhead of 29.58% compared to existing protocols. Short-life session keys are used to achieve mutual authentication between WBAN sensors and monitoring devices. The proposed scheme is analyzed using BAN logic against attacks on impersonation, replay, and unauthorized access using BAN logic. Its practical effectiveness is confirmed via informal analysis, which shows that it is a scalable and efficient solution for practical WBAN environments
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