1,789 research outputs found
Dynamics and ‘normal stress’ evaluation of dilute suspensions of periodically forced prolate spheroids in a quiescent Newtonian fluid at low Reynolds numbers
The problem of determining the force acting on a particle in a fluid where the motion of the fluid and the particle is given has been considered in some detail in the literature. In this work, we propose an example of a new class of problems where, the fluid is quiescent and the effect of an external periodic force on the motion of the particle is determined at low non-zero Reynolds numbers. We present an analysis of the dynamics of dilute suspensions of periodically forced prolate spheroids in a quiescent Newtonian fluid at low Reynolds numbers including the effects of both convective and unsteady inertia. The inclusion of both forms of inertia leads to a nonlinear integro — differential equation which is solved numerically for the velocity and displacement of the individual particle. We show that a ‘normal stress’ like parameter can be evaluated using standard techniques of Batchelor. Hence this system allows for an experimentally accessible measurable macroscopic parameter, analogous to the ‘normal stress’, which can be related to the dynamics of individual particles. We note that this ‘normal stress’ arises from the internal fluctuations induced by the periodic force. In addition, a preliminary analysis leading to a possible application of separating particles by shape is presented. We feel that our results show possibilities of being technologically important since the ‘normal stress’ depends strongly on the controllable parameters and our results may lead to insights in the development of active dampeners and smart fluids. Since we see complex behaviour even in this simple system, it is expected that the macroscopic behaviour of such suspensions may be much more complex in more complex flows
Anti-Yeast Efficacy of Cinnamomum Verum Extracts on Dermatologically Prevalent Yeast Malassezia Furfur
Malassezia furfur, a lipophilic, saprophytic yeast causes superficial skin diseases such as dandruff, pityriasis versicolor, folliculitis, seborrhoeic dermatitis and some forms of atopic dermatitis. The present study was aimed to investigate anti-yeast potential of Cinnamomum verum bark extracts. The powdered plant material was extracted with water and also successively extracted with hexane, chloroform and methanol, using the soxhlet apparatus. The anti-yeast activity was screened by disc diffusion assay and MIC by microdilution method. The results revealed that hexane extract of C. verum exhibited significant anti-yeast activity with Minimum Inhibitory Concentration (MIC) of 0.195 mg mL-1. Qualitative phytochemical tests of C. verum bark extracts was done using standard protocols and demonstrated the presence of phytocompounds such as alkaloids, carbohydrates, flavonoids, glycosides, naphthoquinones, phytosteroids, and terpenoids. Subsequently, high performance thin layer chromatographic analysis (HPTLC), followed by scanning of the spots at 254 nm and 366 nm using a UV detection mode and derivatization method was made to establish the phytochemical profile of C. verum. The results substantiate that hexane extract of C. verum exhibited significant activity to be used as an antimicrobial agen
Two new species of Camallanus (Nematoda: Camallanidae) from freshwater turtles in Queensland, Australia.
We describe 2 new species of Camallanus (Nematoda: Camallanidae) from freshwater turtles collected in Queensland, Australia: Camallanus nithoggi n. sp. from Elseya latisternum (Gray) and Camallanus waelhreow n. sp. from Emydura krefftii (Gray), Emydura macquarrii (Gray), and Em. macquarrii dharra Cann. The only Camallanus sp. previously reported from turtles is C. chelonius Baker, 1983 (all other species in the family have been transferred to Serpinema). The 2 new species described here differ from C. chelonius in the number of male preanal papillae (7 vs. 6 in C. chelonius), the number of male postanal papillae (5 vs. 4 in C. chelonius), and the number of buccal capsule ridges. Additionally, we removed the tissues overlying the buccal capsule and used scanning electron micrographs (SEM) to show that the peribuccal shields extend laterally from the buccal capsule, the basal ring is separated from the buccal capsule by a narrow isthmus, and there is a buttress along the lateral margin of the buccal capsule that has not previously been observed in species of Camallanus
Properties of high-frequency wave power halos around active regions: an analysis of multi-height data from HMI and AIA onboard SDO
We study properties of waves of frequencies above the photospheric acoustic
cut-off of 5.3 mHz, around four active regions, through spatial maps
of their power estimated using data from Helioseismic and Magnetic Imager (HMI)
and Atmospheric Imaging Assembly (AIA) onboard Solar Dynamics Observatory
(SDO). The wavelength channels 1600 {\AA} and 1700 {\AA} from AIA are now known
to capture clear oscillation signals due to helioseismic p modes as well as
waves propagating up through to the chromosphere. Here we study in detail, in
comparison with HMI Doppler data, properties of the power maps, especially the
so called 'acoustic halos' seen around active regions, as a function of wave
frequencies, inclination and strength of magnetic field (derived from the
vector field observations by HMI) and observation height. We infer possible
signatures of (magneto-)acoustic wave refraction from the observation height
dependent changes, and hence due to changing magnetic strength and geometry, in
the dependences of power maps on the photospheric magnetic quantities. We
discuss the implications for theories of p mode absorption and mode conversions
by the magnetic field.Comment: 22 pages, 12 figures, Accepted by journal Solar Physic
Threshold Saturation in Spatially Coupled Constraint Satisfaction Problems
We consider chains of random constraint satisfaction models that are
spatially coupled across a finite window along the chain direction. We
investigate their phase diagram at zero temperature using the survey
propagation formalism and the interpolation method. We prove that the SAT-UNSAT
phase transition threshold of an infinite chain is identical to the one of the
individual standard model, and is therefore not affected by spatial coupling.
We compute the survey propagation complexity using population dynamics as well
as large degree approximations, and determine the survey propagation threshold.
We find that a clustering phase survives coupling. However, as one increases
the range of the coupling window, the survey propagation threshold increases
and saturates towards the phase transition threshold. We also briefly discuss
other aspects of the problem. Namely, the condensation threshold is not
affected by coupling, but the dynamic threshold displays saturation towards the
condensation one. All these features may provide a new avenue for obtaining
better provable algorithmic lower bounds on phase transition thresholds of the
individual standard model
Real and Virtual Compton Scattering off the Nucleon
A review is given of the very recent developments in the fields of real and
virtual Compton scattering off the nucleon. Both real and virtual Compton
scattering reactions are discussed at low outgoing photon energy where one
accesses polarizabilities of the nucleon. The real Compton scattering at large
momentum transfer is discussed which is asymptotically a tool to obtain
information on the valence quark wave function of the nucleon. The rapid
developments in deeply virtual Compton scattering and associated meson
electroproduction reactions at high energy, high photon virtuality and small
momentum transfer to the nucleon are discussed. A unified theoretical
description of those processes has emerged over the last few years, which gives
access to new, generalized parton distributions. The experimental status and
perspectives in these fields are also discussed.Comment: 25 pages, 17 figure
The spiritual revolution and suicidal ideation: an empirical enquiry among 13- to 15-year-old adolescents in England and Wales
The association between conventional religiosity and suicide inhibition has been well explored and documented since the pioneering work of Durkheim. Commentators like Heelas and Woodhead point to ways in which conventional religiosity is giving way in England and Wales to a range of alternative spiritualities, including renewed interest in paranormal phenomena. Taking a sample of 3095 13- to 15-year-old adolescents, the present study examines the association between suicidal ideation and both conventional religiosity and paranormal beliefs, after controlling for individual differences in sex, age and personality (extraversion, neuroticism and psychoticism). The data demonstrate that, while conventional religiosity is slightly associated with lower levels of suicidal ideation, paranormal beliefs are strongly associated with higher levels of suicidal ideation
Treatment Stability and Intermolar Width Changes in Patients Undergoing Surgically Aided Rapid Palatal Expansion: A Systematic Review
Introduction: The primary objectives of this systematic review were to critically evaluate clinical research assessing the stability of treatment outcomes following surgically aided rapid palatal expansion (SARPE) and to review published studies on intermolar width measurements taken before and after the treatment.Materials and Methods: A complete search across the electronic databases of the Cochrane Library, Google Scholar, PUBMED, Europe PMC and Science Direct, and a complimentary manual search of all orthodontic journals until 2024 were carried out. Selection criteria were used in the evaluation of the articles.Selection Criteria: Based on the PICOS (population, intervention, comparison, outcome, study design), the inclusion criteria were established. Adult patients with constricted maxillary arches and resulting transverse discrepancies were included in the study, and SARPE was carried out to address this clinical problem. Although many studies have been conducted on this topic, only randomized clinical trials were covered in this review. Excluded from this review were case reports, conference papers, animal experiments, in vitro research, case series, and FEM studies.Data Collection and Analysis: The primary outcome of the systematic review was the assessment of treatment stability and intermolar width changes in patients who underwent surgically aided rapid palatal expansion (SARPE). The selection of studies and data collection were conducted using standard methodological techniques. The assessment of the risk of bias was conducted, and the results were synthesized. Cochrane Risk of Bias was used for evaluating the outcomes obtained in the various studies. They were assessed by the GRADE protocol for Outcome Assessment for listing the parameters studied.Results: No significant difference in stability was noted between the two groups.Conclusion: With adequate literature review and outcome assessment, it can be concluded from this review that weak evidence exists to conclusively prove the stability of SARPE in the inter-molar and inter-first premolar regions. Immediate post-surgical stability is dependent on a variety of factors that have not been standardized in the various RCTs. Further well-designed trials that establish the extent of transverse discrepancies along with defining the obtained results with clarity are required before we obtain sufficiently conclusive outcomes
Proactive flow control using adaptive beam forming for smart intra-layer data communication in wireless network on chip
Systems-on-chips need numerous predesigned cores to advance. NoC enables Multi-Core SoCs (MC_SoCs). Conventional NoC cores use power and latency on multi-hop wired connections. An effective Wireless Network-on-Chip (WiNoC) architecture can overcome NoC difficulties. On-chip antennas, transceivers, and routers replace multi-hop cable connections with high-bandwidth single-hop wireless networks using WiNoC. Nanotechnology development demands fast data transfer to overcome performance bottlenecks from sharing memory modules and connecting fabrics. This research offers a new Proactive Flow control using Adaptive Beam formation for Smart Intra-layer Data Communication technique(PF_SDC) to optimally use network resources and assure QoS in Wireless Network-on-Chip for next-generation nano-domain technology. Hybrid NoC architecture optimises application admission for data transfer over wired and wireless interconnects. Data traffic is managed by a fuzzy inference-based Intelligent Head Agent (IHA). Queue load predicts router status for the fittest path selection. IHA initiates beams at angles to admit data flow towards the target while utilising the least amount of network power and resources. A simulation model shows that the proposed system may be applied in real-world applications and consumes little power with good throughput
An in Vitro Assessment of the Retentive Property of Orthodontic Molar Bands Cemented With HY Agent-Containing Glass Ionomer Cement
Introduction: In orthodontic treatments, glass ionomer cements (GICs) are the most extensively used adhesive materials. Through an acid-base reaction with enamel and dentin, they function as chelating agents, creating a chemical bond with stainless steel bands. It has been reported that glass ionomer cement (GIC) containing HY agents along with a complex of zinc fluoride, strontium fluoride, and tannic acid offers enhanced retentive strength. This combination contributes to reduced solubility, promotes remineralization, and improves acid resistance. In this in vitro study, Shofu HY Bond glass ionomer cement (HY GIC) was utilized to compare and evaluate the retentive strength of molar bands cemented with it against Voco Meron (VM GIC), a conventional glass ionomer cement.Materials and Methods: The long axis of fifty extracted maxillary first molars was aligned at 90 degrees to the acrylic resin blocks. Of these teeth, twenty-five were bonded using HY-GIC (group 1), while the remaining twenty-five were bonded with Meron GIC (group 2). The retentive properties of both types of glass ionomer cement were evaluated using universal testing equipment. An independent t-test was employed to compare the retentive strength between the two groups.Results: The average retentive strength of bands bonded with HY-GIC was measured at 14.65 ± 1.37 MPa, while bands using Meron GIC had a strength of 10.75 ± 1.10 MPa. The difference between these two values was statistically significant.Conclusion: There was a significant difference in the retentive strength between the 2 groups with Shofu HY bond GIC being superior
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