693 research outputs found
Real-Time Illumination Capture and Rendering on Mobile Devices
We present our efforts to develop methods for rendering 3D objects on mobile devices using real-world dynamic illumination from the user’s environment. To achieve this, we use the front and back cameras on the mobile device to estimate the light distribution in the environment in real time. We then create a dynamic illumination map and render the object at interactive rates in a browser on the device using a web-based graphics API. This project achieves one of the goals of our related work on realistic visualization of virtual objects: to make virtual objects appear to be situated within the scene they are observed in
The use of reflectance measurements in the determination of diffusion of reactive dyes into cellulosic fiber
Reactive dye fixation and color yield of a dyed cellulosic fiber significantly depend on the dye diffusion into the fiber polymer system. In case of pad-dyeing processes, dye diffusion exerts a more significant influence on dye fixation and hence color yield. This article proposes a new method for determining the extent of diffusion of reactive dyes into the fiber in pad dyeings using Kubelka-Munk equation. The K/S values are used as in an equation, %D (extent of dye diffusion) = 100 - [(K/S diffusion index)/ (K/S reference) × 100]. The article introduces and explains how to determine the new K/S variables used in this equation. The new method is simple, nondestructive, relatively faster, and applicable to industrial dyehouses, and was validated by a microscopic analysis of dyed fiber cross-section carried out in this work and to the dye manufacturer's recommendations for dyebath-ingredient concentrations
Digital Modeling of Cultural Heritage Objects
Cultural heritage objects are a rich source of information about human history. Due to the physical nature of these often old and typically rare or unique objects, humanity is at risk of losing this history. Given their importance, preservation is an active area of interest in the research community. While, digitally capturing images of the objects is common practice, we propose a more comprehensive approach to preserving these objects. It involves creating digital models that represent both the three- dimensional shapes of the objects and the materials they are made of
Bone regeneration in implant dentistry: Which are the factors affecting the clinical outcome?
The key factors that are needed for bone regeneration to take place include cells (osteoprogenitor and immune-inflammatory cells), a scaffold (blood clot) that facilitates the deposition of the bone matrix, signaling molecules, blood supply, and mechanical stability. However, even when these principles are met, the overall amount of regenerated bone, its stability over time and the incidence of complications may significantly vary. This manuscript provides a critical review on the main local and systemic factors that may have an impact on bone regeneration, trying to focus, whenever possible, on bone regeneration simultaneous to implant placement to treat bone dehiscence/fenestration defects or for bone contouring. In the future, it is likely that bone tissue engineering will change our approach to bone regeneration in implant dentistry by replacing the current biomaterials with osteoinductive scaffolds combined with cells and mechanical/soluble factors and by employing immunomodulatory materials that can both modulate the immune response and control other bone regeneration processes such as osteogenesis, osteoclastogenesis, or inflammation. However, there are currently important knowledge gaps on the biology of osseous formation and on the factors that can influence it that require further investigation. It is recommended that future studies should combine traditional clinical and radiographic assessments with non-invasive imaging and with patient-reported outcome measures. We also envisage that the integration of multi-omics approaches will help uncover the mechanisms responsible for the variability in regenerative outcomes observed in clinical practice
Quantum illumination using polarization-path entangled single photons for low reflectivity object detection in noisy background
Detecting object with low reflectivity embedded within a noisy background is
a challenging task. Quantum correlations between pairs of quantum states of
light, though are highly sensitive to background noise and losses, offer
advantages over traditional illumination methods. Instead of using correlated
photon pairs which are sensitive, we experimentally demonstrate the advantage
of using heralded single-photons entangled in polarization and path degree of
freedom for quantum illumination. In the study, the object of different
reflectivity is placed along the path of the signal in a variable thermal
background before taking the joint measurements and calculating the quantum
correlations. We show the significant advantage of using non-interferometric
measurements along the multiple paths for single photon to isolate the signal
from the background noise and outperform in detecting and ranging the low
reflectivity objects even when the signal-to-noise ratio is as low as 0.03.
Decrease in visibility of polarization along the signal path also results in
similar observations. This will have direct relevance to the development of
single-photon based quantum LiDAR and quantum imaging.Comment: 8 pages and 6 figure
Second-order correlations and purity of unheralded single photons from spontaneous parametric down-conversion
Various quantum technology applications require high-purity single photons
with high generation rate. Although different methods are employed to generate
such photons, heralded single photons from spontaneous parametric
down-conversion (SPDC) is the most commonly used approach. Photon generation
rate from the heralded single-photon sources are limited by the efficiency of
the detectors to record coincidence detection of the photon pairs which are
lower than the single-photon counts recorded separately on each detector. In
this paper we present a revised expression to calculate second-order temporal
correlation function, for any fixed time window (bin) and report the
experimental characterization of purity of unheralded and heralded single
photons from the SPDC process. With an appropriate choice of time bin for a
given pump power, without heralding we show that higher rate of single photons
with can be generated with very high probability.Comment: 7 pages, 6 figure
Multimilliwatt, tunable, continuous‐wave, mid‐infrared generation across 4.6‐4.7 m based on orientation‐patterned gallium phosphide
We report the generation of tunable continuous-wave (cw) mid-infrared (mid-IR) radiation across 4608–4694 nm using the new nonlinear material, orientation-patterned gallium phosphide (OP-GaP). By exploiting difference-frequency mixing between a cw Tm-fiber laser and a home-built cw optical parametric oscillator in a 40-mm-long crystal, we have generated up to 43 mW of cw output power, with >30 mW across >95% of the mid-IR tuning range. The output at 4608 nm exhibits high beam quality with a passive power stability of 2.5% rms over 1.5 min. The temperature acceptance bandwidth of the OP-GaP crystal has been measured and compared with theory. The performance of the mid-IR source at high pump powers and polarization-dependent transmission in OP-GaP has been investigated.Peer ReviewedPostprint (author's final draft
Naturally Occurring Hydroxy Napthoquinones and Their Iron Complexes as Modulators of Radiation Induced Lipid Peroxidation in Synaptosomes
The modulation of radiation induced lipid peroxidation in synaptosomes by iron (II) and iron (III) complexes of two naturally occurring and therapeutically relevant naphthoquinones viz.
5,hydroxy-1,4 naphthoquinone; juglone and 2,hydroxy-1,4 naphthoquinone; lawsone, have been studied. At lower concentrations the complexes enhance lipid peroxidation predominantly through
redox cycling as observed for Fe(II)- juglonate while at higher concentrations the complexes tend to
limit lipid peroxidation through fast recombinations
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