First use of Deutschs Algorithm in a cluster state quantum computer

first_img Citation: First use of Deutsch’s Algorithm in a cluster state quantum computer (2007, April 18) retrieved 18 August 2019 from https://phys.org/news/2007-04-deutsch-algorithm-cluster-state-quantum.html Finding a way to build a quantum computer that works more efficiently than a classical computer has been the holy grail of quantum information processing for more than a decade. “There is quite a strong competition at the moment to realize these protocols,” Mark Tame tells PhysOrg.com. The latest experiment performed as a collaboration by a Queen’s University theoretical group and an experimental group in Vienna has “allowed us to pick up the pace” of quantum computing. The joint project’s experiment is reported in Physical Review Letters in an article titled, “Experimental Realization of Deutsch’s Algorithm in a One-Way Quantum Computer.”“This is the first implementation of Deutsch’s Algorithm for cluster states in quantum computing,” Tame explains. Tame along with members of the Queen’s group in Belfast, including Mauro Paternostro and Myungshik Kim joined a group from the University of Vienna, including Robert Prevedel, Pascal Böhi, and Anton Zeilinger (who is also associated with the Institute for Quantum Optics and Quantum Information at the Austrian Academy of Sciences) to perform this experiment.“When performing a quantum algorithm,” says Tame, “the standard approach is based on logical gates that are applied in a network similar to classical computing.” Tame points out that this method of quantum computing is not practical or efficient. “Our quantum computer model uses cluster states, which are highly entangled multi-partite quantum states.” The Irish and Austrian group’s quantum computer makes use of four entangled photons in a cluster state. Tame explains how it works:“Our setup is completely based on light, where quantum information is encoded on each photon. The information is in the polarization of each photon, horizontal or vertical, and superpositions in between. An ultra-violet laser pumps a crystal and produces an entangled pair of photons in one direction. The laser beam then hits a mirror and bounces back to form another pair of entangled photons on its second passage through the crystal. These four photons are then made to interact at beamsplitters to form the entangled cluster state resource on which we perform the quantum computation.”Next, Tame says, come the calculations. “We perform Deutsch’s Algorithm as a sequence of the measurements. When you measure in a specific basis, you can manipulate the quantum information in the photons using their shared entanglement.” He continues with an illustration related to classical computing: “You can think of the cluster state as the ‘hardware’, and the measurements as the ‘software’.”Now that the groups in Belfast and Vienna have proved that Deutsch’s Algorithm works for a cluster-based quantum computer, the next step is to apply it to larger systems. “Right now it’s really just a proof of principle,” explains Tame. “We’ve shown it can be done, but we need to build larger cluster states and perform more useful computations.”Tame admits that this next step is where it gets trickier. “Quantum systems like this can be influenced by small fluctuations in the environment. It can be difficult to get accurate computations using larger resources.” He says that noise resistant protocols need to be developed in order to maintain the coherence of the quantum information. “There’s not a lot of noise in the lab during the implementation of experiments on small numbers of qubits. But as we increase this number there are physical and technological concerns that need to be solved. This is a key issue.”And does Tame have any idea how to solve some of these issues? “We have some schemes at the moment. It’s a work in progress.” He pauses. “But for now it’s exciting to have this proof that quantum computing can be efficiently performed with Deutsch’s Algorithm.”Copyright 2007 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com. Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Simulations may explain nanoparticles ‘pinned’ to graphene Quantum computer set up. Image credit: Mark Tame.last_img read more

Read More »

Snail Braille reader could read books to the blind

first_imgThe machine would also feature kinetic recharging, which could possibly allow the reader to charge the device while they are using it. The only snag currently is that this device has not been created. It is currently in the design and prototype stages of development. With proper funding however, this tool could become indispensable to the newly blind. © 2010 PhysOrg.com This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Breakthrough design opens door to ‘full screen’ Braille displays for the blind Explore further (PhysOrg.com) — To most of us, Braille is largely a mystery. It feels really cool, but the idea of actually reading it is kind of a pipe dream. Our sense of touch simply is not as sensitive as that of a blind person. That is not a problem if you happen to have picked up a Braille book out of curiosity. If however, you have recently lost your eyesight, then this is a major problem. As with learning any new language, it takes time to adapt.center_img More information: via Yankodesign That time can be very frustrating, since writing and reading are still important forms of communication in our society. That is where a tool such as the Snail Braille reader could come in handy. Citation: Snail Braille reader could read books to the blind (2011, May 6) retrieved 18 August 2019 from https://phys.org/news/2011-05-snail-braille-reader.html This tool takes Braille text, and by rolling over a straight line of Braille text, the machine is able to read the Braille, and then translate it into speech. The machine, which is capable of storing text for latter replay, can also be paired with a standard Bluetooth headset, similar to the ones you get with your cell phone. That is good news for students who want to study without having to search for the page in a book, or for people who like to hear the instructions while they are completing a task. last_img read more

Read More »

Four new giant planets detected around giant stars

first_imgArtist’s concept of a giant extrasolar planet. Credit: NASA/JPL-Caltech. The team, led by Matias Jones of the Pontifical Catholic University of Chile, made the discovery during observations under the EXPRESS (EXoPlanets aRound Evolved StarS) radial velocity program. They used two telescopes located in the Atacama desert in Chile: the 1.5 m telescope at the Cerro Tololo Inter-American Observatory and the 2.2 m telescope at La Silla observatory. Complementary observations were conducted at the 3.9 m Anglo-Australian telescope in Australia.Using spectrographs mounted on these telescopes, the researchers were monitoring a sample of 166 bright giant stars that are observable from the southern hemisphere. They took several spectra for each of the stars in the sample thanks to these instruments. The observation campaign lasted from 2009 to 2015.The astronomers have computed a series of precision radial velocities of four giant stars: HIP8541, HIP74890, HIP84056 and HIP95124. According to them, these velocities show periodic signal variations. The team concluded that the most probable explanation of the periodic radial velocity signals observed in these stars must be the presence of planetary companions.”These velocities show periodic signals, with semi-amplitudes between approximately 50 to 100 ms−1, which are likely caused by the doppler shift induced by orbiting companions. We performed standard tests (chromospheric emission, line bisector analysis and photometric variability) aimed at studying whether these radial velocity signals have an intrinsic stellar origin. We found no correlation between the stellar intrinsic indicator with the observed velocities,” the paper reads.HIP8541b is the most massive of the newly found quartet of planets. With a mass of about 5.5 Jupiter masses, this exoplanet also has a much longer orbital period than the other three worlds, equal to 1,560 days. Its parent star is slightly more massive than the sun and has a radius of nearly eight solar radii.HIP74890b and HIP84056b are very similar in terms of mass and orbital period. The mass of HIP74890b is estimated to be 2.4 Jupiter masses, what is about 92 percent of the mass of HIP84056b. The more massive planet of this comparable duo has an orbital period lasting nearly 819 days – about three fewer days than the other planet. Their host stars are also of similar mass and size, about 1.7 the mass of the sun, with a radius of 5.03 (HIP 84056) and 5.77 (HIP 74890) solar radii.Among the exoplanets described in the paper, the one with the shortest orbital period (562 days), is designated HIP95124b. It has a mass of 2.9 Jupiter masses and orbits a star nearly two times more massive than the sun, with a radius of 5.12 solar radii.The discovery of these planets also yielded interesting results about correlations between the stellar properties and the occurrence rate of planets. The researchers have found that giant planets are preferentially detected around metal-rich stars. “We also present a statistical analysis of the mass-metallicity correlations of the planet-hosting stars in our sample. (…) We show that the fraction of giant planets increases with the stellar mass in the range between 1 to 2.1 solar masses, despite the fact that planets are more easily detected around less massive stars,” the scientists noted.The team concluded that the high fraction of multiple systems observed in giant stars is a natural consequence of the planet formation mechanism around intermediate-mass stars. Explore further (Phys.org)—An international team of astronomers reports the discovery of four new giant exoplanets orbiting stars much bigger than our sun. The newly detected alien worlds are enormous, with masses from 2.4 to 5.5 the mass of Jupiter and have very long orbital periods ranging from nearly two to slightly more than four Earth years. The findings were published on Mar. 11 in a research paper available online at arXiv.org. More information: Four new planets around giant stars and the mass-metallicity correlation of planet-hosting stars, arXiv:1603.03738 [astro-ph.EP] arxiv.org/abs/1603.03738AbstractCONTEXT. Exoplanet searches have demonstrated that giant planets are preferentially found around metal-rich stars and that their fraction increases with the stellar mass. AIMS. During the past six years, we have conducted a radial velocity follow-up program of 166 giant stars, to detect substellar companions, and characterizing their orbital properties. Using this information, we aim to study the role of the stellar evolution in the orbital parameters of the companions, and to unveil possible correlations between the stellar properties and the occurrence rate of giant planets. METHODS. Using FEROS and CHIRON spectra, we have computed precision radial velocities and we have derived atmospheric and physical parameters for all of our targets. Additionally, velocities computed from UCLES spectra are presented here. By studying the periodic radial velocity signals, we have detected the presence of several substellar companions. RESULTS. We present four new planetary systems around the giant stars HIP8541, HIP74890, HIP84056 and HIP95124. Additionally, we find that giant planets are more frequent around metal-rich stars, reaching a peak in the detection of f = 16.7+15.5−5.9% around stars with [Fe/H] ∼ 0.35 dex. Similarly, we observe a positive correlation of the planet occurrence rate with the stellar mass, between M⋆ ∼ 1.0 -2.1 M⊙, with a maximum of f = 13.0+10.1−4.2%, at M⋆ = 2.1 M⊙. CONCLUSIONS. We conclude that giant planets are preferentially formed around metal-rich stars. Also, we conclude that they are more efficiently formed around more massive stars, in the mass range of M⋆ ∼ 1.0 – 2.1 M⊙. These observational results confirm previous findings for solar-type and post-MS hosting stars, and provide further support to the core-accretion formation model. © 2016 Phys.org Astronomers discover two new ‘hot Jupiter’ exoplanets Citation: Four new giant planets detected around giant stars (2016, March 15) retrieved 18 August 2019 from https://phys.org/news/2016-03-giant-planets-stars.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

Read More »

Hypothetical new particle could solve two major problems in particle physics

first_img“The principle of lepton universality is a pillar of the standard model,” Miller said, referring to the idea that all leptons, including electrons and muons, should behave in the same way. “Our particle violates this principle, because interactions with muons and electrons are different.”The second problem involves the muon’s anomalous magnetic moment, which is a measure of how quantum effects contribute to the magnetic moment of a particle. So far, the most precise measurement disagrees with the standard model by more than three standard deviations. Once again, physicists think that the discrepancy may indicate physics beyond the standard model, or else more accurate measurements are needed. If the answer is new physics, then the new particle suggests that the proton and muon problems may be related.”The proton radius puzzle can be explained if there is a new additional attractive interaction between the muon and proton,” Miller said. “Such an interaction must also contribute to the muon anomalous magnetic moment. The proton radius puzzle (contribution to the Lamb shift) determines the strength of the interaction that contributes to the muon anomalous magnetic moment. The new contribution is just large enough to account for the current disagreement between theory and experiment. The equations in our paper allow us to obtain definite numbers, and these numbers can work out to be just right to account for both puzzles. New experiments will determine whether this is true physics or just a coincidence.”The physicists emphasize that they make no assumptions about the hypothetical particle other than that it could explain both of these puzzles. By constraining the mass of the hypothetical particle using data from previous experiments, the physicists predict that its mass would lie somewhere between 100 keV and 100 MeV. Although previous experiments have already explored part of this predicted range, the physicists have identified two unexplored regions that may be ideal places to look. They expect that future high-precision experiments involving protons and muons may be able to search for the particle in these regions. “We constrain the parameter space (mass and couplings) of this new particle in a finite range (except for the coupling of electrons),” Liu said. “So experimentalists can discover or exclude it by looking at a specific place, instead of measuring zero more and more accurately, like in the electron experiments.”In the meantime, the physicists are also looking forward to improved measurements of the muon anomalous magnetic moment—if the discrepancy remains, the results will offer further support for the existence of the new particle. The scientists also plan to apply some of the methods they developed here to look for other new particles.”Our work on this has allowed us to develop new theoretical tools to aid in the search for other kinds of bosons with different quantum numbers,” Miller said. “We will be applying those tools. Another direction is to develop a deeper theory that accommodates our new boson.” New measurement with deuterium nucleus confirms proton radius puzzle is real © 2016 Phys.org (Phys.org)—Although the Large Hadron Collider’s enormous 13 TeV energy is more than sufficient to detect many particles that theorists have predicted to exist, no new particles have been discovered since the Higgs boson in 2012. While the absence of new particles is informative in itself, many physicists are still yearning for some hint of “new physics,” or physics beyond the standard model. Explore further Journal information: Physical Review Letters Citation: Hypothetical new particle could solve two major problems in particle physics (2016, September 8) retrieved 18 August 2019 from https://phys.org/news/2016-09-hypothetical-particle-major-problems-physics.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. In a new paper published in Physical Review Letters, physicists Yu-Sheng Liu, David McKeen, and Gerald A. Miller at the University of Washington in Seattle have hypothesized the existence of a new particle that looks very enticing because it could simultaneously solve two important problems: the proton radius puzzle and a discrepancy in muon anomalous magnetic moment measurements that differ significantly from standard model predictions.”The new particle can account for two seemingly unrelated problems,” Miller told Phys.org. “We also point out several experiments that can further test our hypothesis.”The physicists describe the hypothetical new particle as an “electrophobic scalar boson.” Currently there are five bosons in the standard model, only one of which is a scalar (the Higgs), meaning it has zero spin. All five bosons have been experimentally confirmed, and all are force carriers that play a role in holding matter together.One of the distinct features of the new hypothetical particle is that, although it is predicted to bind to protons and neutrons, it would bind very weakly or not at all to electrons, making it “electrophobic.” The scientists showed that this electrophobic property would allow the particle to solve both the proton and muon problems.In the proton radius puzzle, the problem is that the proton radius seems to have a different size depending on what type of particle is orbiting it. Experiments have found that the proton radius is slightly larger when it is orbited by an electron than when it is orbited by a muon, which is identical to the electron except for being 200 times heavier. Assuming that the discrepancy is not due to measurement error (which it very well may be, considering how difficult it is to measure a particle that is less than a femtometer [10-15 meters] across), the results may point to the existence of a previously unknown fundamental force that pulls protons and muons closer together, but does not act between protons and electrons. Using constraints from previous experiments, the physicists identified two regions, A and B (dotted), to search for the new particle in proposed experiments. Credit: Liu et al. ©2016 American Physical Society More information: Yu-Sheng Liu, David McKeen, and Gerald A. Miller. “Electrophobic Scalar Boson and Muonic Puzzles.” Physical Review Letters. DOI: 10.1103/PhysRevLett.117.101801. Also at arXiv:1605.04612 [hep-ph]last_img read more

Read More »

3D grayscale digital light printing gDLP highly functionally graded materials FGM

first_img Compression of 2D lattice metamaterial. The movie play speed is 5X fast-forward. The FEM simulation predicts the experimental results well. Credit: Science Advances, doi: 10.1126/sciadv.aav5790. FTIR spectra showing the two-stage curing for practical printing. (A) The hybrid ink using a G70 light for printing. (B) The enlarged area showing the double bond evolution during the two-stage curing. (C) The enlarged area showing the epoxide group evolution during the two-stage cure. The hybrid ink was cured forming a network by photopolymerization. The following thermal curing results in both the decrease of the double bond and epoxide group. The residual monomer and dangling functional groups, such as end-terminated double bond and dangling epoxide group, would be further reacted by the diamine cross-linker to form more linkages. Credit: Science Advances, doi: 10.1126/sciadv.aav5790. LEFT: Applications of g-DLP–printed composites for sequential SMP components and 4D printing. (A) Design and print part of a helical SMP component with increasing grayscale level on the hinge from G20 to G80. (B) Snapshot showing the sequential shape recovery process of the helical SMP component with graded hinge materials in hot water (~60°C). (C) Design and print part of a sequential SMP as an artificial arm. (D and E) Snapshot showing sequential shape recovery of a single artificial arm (D) and artificial arms for soft robotics to lift a stick (E) by a heat gun. (F) Schematic of a shape-shifting film by cold drawing of printed lamina fiber-reinforced composites with asymmetric fiber distribution and recovery process. (G) Pictures of the printed strip with 0° of fiber orientation: original shape and bending shapes by applied stretching strain at room temperature. Scale bars, 1 cm. Photo credit: Xiao Kuang, Georgia Tech. RIGHT: Encryption via diffusion-assisted coloring for graded materials. (A) Two-stage cured films enabled by a continuous gradient grayscale pattern (inside G80 to outside G0) across the radius were immersed in fluorescein (B) or dye (C) solution followed by washing and drying to visualize the grayscale pattern by UV light and visible light, respectively. (D) Coloring kinetics of the film in (A) by analyzing the red value (RGB color) of the images. (E) Two-stage cured films using the design of staggered discrete gradient grayscale (G80 and G0) concentric circle pattern. The samples in (E) were colored using cyan dye solution and corresponding red value of image across the sample (F) as well as fluorescein solution and the green value of image across the section (G). (H) Design of a grayscale pattern for QR code and corresponding images of the colored pattern using fluorescein under UV light. (I) Design of a grayscale pattern for a name card colored with black dye solution. Scale bars, 5 mm. Photo credit: Xiao Kuang, Georgia Tech. Credit: Science Advances, doi: 10.1126/sciadv.aav5790. g-DLP 3D printing of FGM via two-stage curing. (A) Schematics showing the g-DLP printing of graded material via a two-stage curing process. A hybrid ink was used for DLP 3D printing first followed by thermal curing the printed part in a heating oven. (B) Predicted normalized conversion of cured material under different grayscale light with only one exposure (solid lines) and multiexposure (dashed lines) by the model using the exposure time of 20 s and curing thickness of 60 μm per layer. (C) Gel fraction of hybrid ink after the first- and second-stage curing. (D) Tensile stress-strain curves of printed materials using different grayscale during printing (sample size, >3). (E) Young’s modulus and glass transition temperature of printed materials as functions of grayscale. (F and G) Design, print part under bending, and corresponding FEM simulation of graded materials enabled by g-DLP using a discrete gradient (F) and a continuous gradient (G) grayscale pattern. Scale bars, 5 mm. Credit: Science Advances, doi: 10.1126/sciadv.aav5790 This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. 4-D printing reversible shape changing materials with light-based grayscale patterning Three-dimensional (3-D) printing or additive manufacture (AM) is a popular technique that has presently attracted tremendous attention as a promising method to revolutionize design and manufacture. Researchers have expanded its applications from rapid prototyping to tissue engineering, electronic devices, soft robotics and high-performance metamaterials, but most 3-D printing techniques only use a single material to print parts or form components using multiple discrete properties with complex mechanical gradients that cannot be cohesively controlled. © 2019 Science X Network 4-D printing shape memory polymers (SMPs) and encryption assisted by diffusion The g-DLP-printed material could be programmed or tuned across a temperature range (Tg) from 140 C to 680 C for use as a shape memory polymer (SMP), which exhibited actuation at different temperatures. To demonstrate this, they engineered a helical pattern, which when heated to 600 C opened to form a straight line, followed by cooling in ice to reverse to the original conformation. However, if the helical structures were printed with the same grayscale (G20), all hinges recovered their shape simultaneously at the same speed, albeit without shape recovery to the original architecture. The scientists then investigated the applications of such SMPs by developing a robotic arm.Since the graded materials had different moduli and Tg, this led to different diffusivity in the experimental system. The scientists were therefore able to view the diverse grayscale patterns with a variety of coloring dyes. Kuang et al. propose using fluorescein coloring for encryption and anti-counterfeiting applications. For instance, when the scientists included a QR (quick response) code into a film using grayscale patterning for printing, followed by fluorescein treatment, the pattern only became visible under UV light and invisible under visible light. Furthermore, when Kuang et al. printed a QR code as a grayscale pattern and scanned it using a smartphone, the scientists were able to directly link to the information or site encoded via the internet, preventing counterfeit 3-D products. In this way, Kuang et al. developed a g-DLP 3-D printing technique via two-stage curing to achieve high-resolution digital manufacture with complex shapes and programmable functional gradients. The scientists aim to optimize constituents in the material for additional printing applications. They were able to directly develop complex 2-D/3-D lattices, metamaterials, 4-D printing with shape memory polymers and produce anticounterfeit techniques that were built-in to the 3-D material itself. The scientists aim to further improve the new g-DLP method to engineer materials for future applications, including 4-D printing metamaterials, biomimetic presurgical models, soft robotics and additive manufacture with ingrained cyber security. Printing graded metamaterials with g-DLP (grayscale digital light printing) for multifunctional materialsThe scientists then used g-DLP to explore the design and fabrication of lattice and cellular structures in the study. For this they first printed a 2-D lattice architecture matrix with a grayscale pattern of a triangular region and a blank space beneath it. During compression studies the deformation only occurred in the triangular region with soft material, where the space under the triangular band did not deform to provide a shield that protected any material under this region. The scientists showed that such controlled buckling could enhance the energy absorption capability – verified using the stable stress drop in the accompanying stress-strain curve. As before, the FEM simulation accurately predicted the experimental results.Kuang et al. then designed a 3-D lattice architecture, where they assigned each layer with a different grayscale value to obtain a clean, printed lattice with high resolution. The architecture of the 3-D lattice showed sequential deformation behavior – with applications in energy absorption. The scientists can harness the graded material properties of the g-DLP printing technique to manufacture pre-surgical models. For instance, using the method they printed tissue-like structures with bioinspired mimicry to create bone (with grayscale G0), soft muscle (G85) and skin (G70) structures. They were also able to design a small-scale artificial limb structure with soft muscle (G85) and hard bone (G0), which was printed using the g-DLP method. Kuang et al. propose using the technique to engineer customized architectures with patient-specific physical properties to form presurgical models in tissue engineering for regenerative medicine. Explore further Introducing g-DLP (grayscale digital light printing) to develop digital materialsIn the present work, Kuang et al. developed a new, two-stage curing hybrid ink system in a single-vat to achieve grayscale digital light processing (g-DLP) 3-D printing. They synthesized the hybrid ink using bisphenol A ethoxylate diacrylate (BPADA), glycidyl methacrylate (GMA), a diamine crosslinker, n-butyl acrylate (BA), photoinitiators and photoabsorbers. In the experimental setup, they used monochromatic light intensity settings to cure the resin layer-by-layer, analogous to the CLIP technique. For this, they used an oxygen permeable membrane to separate the cured section from the window for faster printing. The scientists first sliced the designed structure into images corresponding to individual printing layers, followed by processing each image with a MATLAB code to generate the grayscale distribution containing the desired properties. They then passed the images of individual layers with grayscale patterns to the UV projector for printing. Compression of 3D anisotropic lattice. Compression of the 3D isotropic lattice. The movie play speed is 10X fast-forward. The compression tests were performed in different directions. Credit: Science Advances, doi: 10.1126/sciadv.aav5790 Researchers therefore pursued many other 3-D printing methods including fused filament fabrication and direct ink writing, although these techniques were not pursued further due to slow printing rates. When they used digital light processing (DLP) based on digital micromirror devices (DMDs) as a rapid, high-resolution AM approach, the polymer resins cured abruptly and were too fast in comparison. While methods in the past demonstrated limited capacity to practically manufacture functionally graded materials with tunable properties. In a more recent technique, scientists developed continuous liquid interface production (CLIP) as a true breakthrough to offer the fastest 3-D printing technology close to the production level; also relevant to the present work. More information: Xiao Kuang et al. Grayscale digital light processing 3-D printing for highly functionally graded materials, Science Advances (2019). DOI: 10.1126/sciadv.aav5790 Sean V Murphy et al. 3-D bioprinting of tissues and organs, Nature Biotechnology (2014). DOI: 10.1038/nbt.2958 Yoonho Kim et al. Printing ferromagnetic domains for untethered fast-transforming soft materials, Nature (2018). DOI: 10.1038/s41586-018-0185-0 Citation: 3-D grayscale digital light printing (g-DLP) highly functionally graded materials (FGM) (2019, May 21) retrieved 18 August 2019 from https://phys.org/news/2019-05-d-grayscale-digital-g-dlp-highly.html Journal information: Science Advances Comparatively, most natural structures such as fish scales and tendon-to-bone are made of a variety of materials with markedly different properties that function together. As an alternative, functionally graded materials (FGM) have drawn substantial recent research interest to improve the mechanical robustness and flow tolerance of substrates. This allows for FGM 3-D printing with widely tunable printing properties in a single process, which has increasing importance in materials science. In a recent study, now published in Science Advances, Xiao Kuang and colleagues at the interdisciplinary departments of Mechanical Engineering, Nanobiomechanics and Advanced Structure Technology in China and Canada presented a single-vat grayscale digital processing (gDLP) 3-D printing method. In the work, they used grayscale light patterns and a two-stage curing ink to obtain functionally graded materials (FGMs) with high resolution and mechanical gradients up to three orders of magnitude. To demonstrate the method, they developed complex 2-D and 3-D lattices with controlled buckling and deformation sequences, metamaterials with a negative Poisson’s ratio, presurgical models with varying stiffness, composites for 4-D printing and a method to anti-counterfeit 3-D printing. 3-D printing techniques at a glance For advanced 3-D printing applications, researchers had demonstrated the PolyJet method with multiple inkjet printheads to simultaneously deposit different materials on the printing bed. However, the method had some notable drawbacks including high equipment cost, rigorous resin requirements, limited material choices and a relatively low resolution multimaterial printing mode. , Nature , Nature Biotechnology During the experiments they induced radical-based photopolymerization to form the polymer network and printed structure, and showed that the crosslinking density and modulus of the material decreased with increased grayscale percentage. In the work, the GMA monomer and the diamine crosslinker played a critical role in the thermal curing process and determined the effects of grayscale photopolymerization of the hybrid ink. Kuang et al. showed the method’s nonlinear dependence on light intensity and developed reaction kinetics models to examine time-dependent light curation. The scientists prevented light leakage-based resolution reduction in the setup by adjusting the software using an optical system with smaller magnification, or via increased photoabsorber content to improve the resolution of printed materials. They monitored the chemical structure evolution during photocuration with Fourier Transform Infrared Spectroscopy (FTIR) and tested the mechanical and thermomechanical properties of the materials. Kuang et al. included tests on the Young’s modulus and glass transition temperature (Tg) as functions of the grayscale percentage to characterize the new material. Since the method offered the potential to create digital materials by controlling the grayscale, the scientists followed the initial experiments by printing samples of simple geometry with graded properties. They also used finite element modeling (FEM) simulations to predict the graded properties and deformation rates of the architectures to enable a continuous gradient pattern. This allowed Kuang et al. to manufacture a continuously graded material that bent with continuously changing curvature on application of a point load. The scientists showed that the experimental results agreed with the simulation on single-point bending behavior. last_img read more

Read More »

Its a high five

first_imgDirected by Devesh Nigam, the one and half hour play will bring some of the most interesting stories penned by eminent writers like – Anton Chekhov, O Henry, Guy de Maupassant and Manto in a single stage act.From feel good comedy, black humor, tragedy to the intense drama, the genre and presentation of each story gives a roller coaster ride of emotions and certainly the best works of these famous writers.Each story presents a particular emotion and feeling which forms the basic nature of humanity and how it helps in tough times in dealing with dreams, hardship, success, miseries and failures etc.The cast of the play are – Rohit Kumar, Anshul Pandey, Ayushi Aggarwal, Shorya Sehgal, Raghav Gahlout, Ayana Bansal, Neelesh Bisht, Roshan Raj, Siddarth Singh, Tanvi Tyagi, Satyendra Yadav, Shiv Dutt, Sunidhi Awasthi, Shubham, Anisha Singh and Dagar Sonu.When: 14 September Where: Akshara Theatre, Baba Kharag Singh MargTiming: 7pm Ticket Price: Rs 200 – 300last_img read more

Read More »

Dancing the art

first_imgConfluence of Form a solo show by Singapore based artist Sunaina Bhalla in collaboration with Odissi dancer Chitra Shankar will be presented at Art Konsult, Lado Sarai, in the capital from December 22 – 30.The show will be interpreting Sunaina’s paintings through dance.  Alka Pande will introduce the show followed by a talk by Sunaina interspersed with a dance demonstration on the confluence of the two art forms of painting and dance.  Chitra will be demonstrating the different ‘moods’ of the poem depicted in Sunaina’s paintings through dance gestures.   Also Read – ‘Playing Jojo was emotionally exhausting’Sunaina is a contemporary artist of Indian origin, who currently lives and works in Singapore. Born and educated in India, she moved to Tokyo in the late 90’s and has spent the last two decades in various parts of North and South Asia. Having completed her formal education as a textile designer specializing in print, she chose to pursue an immersive education in Nihonga, when living in Japan and spent 5 years working under Ohta-sensei of the Kyoshin-Do school, studying Sumie-e and Nihonga – the traditional Japanese art forms of painting.Her work is, in essence, a confluence of her experiences and observations in diverse situations and contrasting cultures.  Quite naturally her imagery revolves around the societal impact of economic, political and religious issues prevalent today, and represents her interpretation of social change in a rapidly shrinking world changing at an incredibly fast pace.last_img read more

Read More »

Ghoshs way of instigating party workers against cops unfortunate

first_imgKolkata: The Trinamool Congress Secretary General Partha Chatterjee on Friday launched a scathing attack on state BJP president for instigating party workers to attack policemen.While addressing BJP workers at the thana gherao programme organised by the party to protest against TMC’s atrocities during the three-tier Panchayat elections and after, Ghosh said the police force had been working as agents of the Trinamool Congress. “It may so happen that our party workers may attack police stations and put them on fire. Also, they may attack houses of police officers.” Also Read – Heavy rain hits traffic, flightsComing down heavily on the BJP, Chatterjee said: “It is unfortunate that the state president of a party is using such language which is unparliamentary. It reflects nothing else but Ghosh’s bad taste.” Chatterjee said his body language and the expressions he used do not go with the political culture of Bengal. “The way he is instigating his party workers against the police is most unfortunate. The people of Bengal are watching his behaviour and they will give a befitting reply during the elections,” he said. Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedHe said “BJP is such a shameless party that despite being a distant second the leaders have failed to assess the minds of the people of Bengal. The state has a political culture and tradition and any attempt to terrorise the police force or divide people on the basis of religion will become a boomerang.” It may be recalled that BJP national president Amit Shah during his visit to the city in 2017 had asked Ghosh to “use his language carefully” at a press conference at the Kolkata Press Club.last_img read more

Read More »

Intellectuals slam NRC final draft call it unscientific

first_imgKolkata: Intellectuals from Bengal on Friday raised questions on the procedure of publication of the final draft of Assam’s National Register of Citizens (NRC) omitting the names of around 40 lakh people.The issue has already triggered a political slugfest across the country with many from Bengal standing by those whose names did not figure in the draft. Now, Bengal’s intellectuals have criticised the method by calling it “unscientific”. They also assured that a rally would be organised in the city as a token of protest and they may also visit Assam to further strengthen their movement. Also Read – Rain batters Kolkata, cripples normal lifeDuring a press conference in the city, the prominent intellectuals have sent across the message that Bengal will stand by those whose names were “illegally omitted” in the final draft. The Bengal intelligentsia trained their guns at the Narendra Modi government for “dividing people” on the basis of religion.”A democratically elected government at the Centre has been acting like a fascist. A country like India where so many religions co-exist cannot be divided on the basis of language, religion or caste. The family members of those who have passports, voter cards and other documents cannot be driven out of the country in this manner attaching a tag of an illegal intruder,” artist Subhaprasanna Bhattacharjee. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedEconomist Abhirup Sarkar pointed out a pertinent issue where he discussed that these 40 lakh people out of a total of 3 crore in Assam cannot be illegal intruders. If what Centre is claiming is true, then what was the role of Central agencies including the BSF to check the illegal infiltration of such a huge number?”Around 13 percent of the total population cannot be illegal intruders. The method which was followed was full of flaws. Many people, particularly the poor do not have birth certificates, Madhyamik certificates or other documents that are mentioned in the draft,” Sarkar said. Poet Subodh Sarkar asked why the Centre has issued voter cards, Aadhar cards to those whose relatives have been omitted from the list. The Modi government was voted into power by those who have been declared as”illegal citizens”.”We are witnessing a difficult time. The Modi government has been doing worse than what Hitler did. The people whose family members are in various professions cannot be attributed a tag of “illegal intruders”. We, the Bengalis, will not tolerate this and fight for them.”Theatre personality Bibhash Chakraborty demanded that the Centre must clarify on what basis the names of these 40 lakh people have beenomitted.”It is very unfortunate to prove themselves as Indians who have been living in this country for a long time,” Chakraborty mentioned.Artist Subhaprasanna observed that similar to the Centre’s decision in regard to demonetization, this NRC will also prove to be a disaster.last_img read more

Read More »

Bodies of mother infant found at Baranagar residence

first_imgKolkata: Mystery shrouds the death of a 32-year-old woman and her-one-and-half-year old daughter whose bodies were found inside their house in Baranagar on Tuesday night.The victim woman, Soma Bhowmik, was found lying on her bed with her throat slit, while her daughter had a cut injury on her right wrist. The girl was found in the adjacent room. The incident took place when the woman’s husband, Subhajit was away from home. Both the victims were declared dead by doctors. Also Read – Rain batters Kolkata, cripples normal lifePolice said Subhajit, an employee of a private company, had returned home from office at around 10 pm on Tuesday and found that the front gate of the house open.As he entered the bed room, he found that his wife was lying on the bed with injuries around her neck and the daughter on the floor of an adjacent room. After being alerted by the screams of Bhowmik, locals rushed to the spot and informed the local police station.The victims were taken to a nearby hospital where the doctors pronounced them brought dead. The doctors have confirmed that both the victims have died in the afternoon. Police are waiting for the autopsy report that might throw some light on the nature of their deaths.According to a preliminary investigation, police suspect that the woman might have committed suicide by slitting her throat after killing her daughter.Police are not ruling out the possibility of a foul play behind the incident. No suicide note was found inside the roomPolice came to know that Bhowmik had married the woman around three years ago.last_img read more

Read More »