Month: August 2019

Password retrieval in lost or stolen iPhonesiPads takes six minutes w Video

first_img(PhysOrg.com) — A team of researchers has demonstrated how passwords in iPhones and iPads can be retrieved from a stolen or lost device in only six minutes, even if it is locked. The passwords can include access passwords for corporate networks. The demonstration showed the researchers were able to retrieve passwords in the keychain but not in other protection classes. They were able to access and decrypt passwords for Google Mail (as an MS Exchange account), voicemail, virtual private network (VPN), WiFi, some Apps, various MS Exchange accounts and Lightweight Directory Access Protocol (LDAP) accounts.The researchers said with the SIM card removed from the device they could also access email passwords and access codes for corporate WLANs and VPNs. Having access to email passwords gives the attacker even more passwords since many passwords are reset simply by requesting a reset and providing the email address. Screenshot of Proof of Concept approach with truncated Output of revealed Password Scientists at the Fraunhofer Institute for Secure Information Technology (SIT) test laboratory in Germany have shown how someone who steals or finds an iPhone or iPad can use existing software to “jailbreak” the device and gain access to the command shell. A secure shell (SSH) server can then be installed to enable them to run their own software on the device. Both procedures can be carried out even if the device is locked.The attackers can then upload a script to the device to use the device’s own tools to give them access to the keychain, which is Apple’s password management system. The keychain entries can then be downloaded to the attacker’s computer.The attack is successful because in the current operating system in “i” devices (iOS) large parts of the file system are accessible even if the device is locked, and the cryptographic key is not protected by the passcode. Explore further © 2010 PhysOrg.com The researchers recommended that anyone who loses an iOS device or has it stolen should immediately change all their passwords for all accounts, even those not stored in the iPhone or iPad. They also warned that similar or identical passwords to those the attackers might access on the device are especially vulnerable to hacking. They said that encryption is no protection because the encryption relies on the secret information that would be revealed by the attack.The attack is easy to conceal, and this means that devices left unattended even for just a few minutes could be vulnerable.center_img Credit: research paper (see link below) More information: www.sit.fraunhofer.de/en/Image … rds_tcm502-80443.pdf Germany warns of Apple security problem Citation: Password retrieval in lost or stolen iPhones/iPads takes six minutes (w/ Video) (2011, February 11) retrieved 18 August 2019 from https://phys.org/news/2011-02-password-lost-stolen-iphonesipads-minutes.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

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Tiny tech big results Quantum dot solar cells increase solar conversion efficiency

first_img More information: Tandem colloidal quantum dot solar cells employing a graded recombination layer, Nature Photonics 5, 480–484 (2011), Published online 26 June 2011, doi:10.1038/nphoton.2011.123 3D confined electron wave functions in a Quantum Dot. Here, rectangular and triangular-shaped quantum dots are shown. Energy states in rectangular dots are more ‘s-type’ and ‘p-type’. However, in a triangular dot the wave functions are mixed due to confinement symmetry. Image courtesy Wikipedia (c) Saumitra R Mehrotra & Gerhard Klimeck nanohub.org/resources/8805 Sometimes called artificial atoms, nanoparticles composed of cadmium, zinc, tellurium, selenium, sulfur and other compounds are so miniscule that adding or removing a single electron represents a significant change – a property that makes them suitable not only as components of advanced solar cells, but also in solid state lighting, medical sensors and other applications.In particular, colloidal quantum dots (CQDs) – synthesized from a three-component system composed of: precursors, organic surfactants, and solvents – can be tuned by changing their size, which in photovoltaic structures allows their spectral response to be tailored as needed. Recently, researchers in the Department of Electrical and Computer Engineering at the University of Toronto have demonstrated the first CQD tandem solar cells (a series of connected solar cell in which adding more devices allows for each device to be optimized to a narrower spectrum giving a higher overall efficiency) using the size-effect tuning of a single CQD material, lead(II) sulfide (PbS). Their ability to tune CQD films may allow tandem and multi-junction solar cells (fabricated by combining CQDs of differing sizes) to raise solar cell conversion limits from its current 31% to 42% 49%, respectively.The research – led by Prof. Edward H. Sargent, along with Xihua Wang, Ghada I. Koleilat, and other University of Toronto researchers – overcame the difficulties encountered by previous CQD photovoltaic research, which were stonewalled by a key missing piece: the junction – the point of connection – between the front and back cells. “Prior to our paper,” says Sargent, “there had been no prior reports of a colloidal quantum dot solar cell that efficiently matches the currents in the front, or visible-wavelength-bandgap, cell, and the back infrared-bandgap cell, and that successfully sums the voltages in each cell. We developed a new technique – which we term the Graded Recombination Layer – that connects the front and back cells with essentially no performance loss through a series of materials that gradually transfer front cell activity to that of the back cell.” The key is that this stack of materials is highly transparent, and therefore proved highly effective in building the first efficient colloidal quantum dot tandem cell. At this point, adds Sargent, “The main advanced need in CQD photovoltaics is improved transport within the colloidal quantum dot layer itself. This will benefit single-junction and multi-junction solar cells alike.”In terms of applications, Sargent notes that “Once we exceed 10% solar power conversion efficiency (today the best reports for CQD photovoltaics are 5.6%, so we still have a way to go), we will be poised to create flexible, large-area solar cells at low cost. Specifically, out target efficiency combined with our low materials and manufacturing costs will lead to a dramatic improvement in overall installed cost per Watt*peak.” Researchers crack full-spectrum solar challenge Copyright 2011 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 furthercenter_img 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. Colloidal semiconductor nanocrystals irradiated with ultraviolet light. Quantum confinement causes the band gap energy to vary with the nanocrystal’s size. Each vial contains a monodisperse sample of nanocrystals dispersed in a liquid solvent. Image courtesy Wikipedia (c) walkman16 The race to achieve ever-higher photovoltaic conversion ratios is, so to speak, a hot area of research. One line of research has focused on quantum dots – semiconductor nanocrystals under 2-10 nanometers (about 10-50 atoms) in diameter in which electron motion is confined in all three dimensions – as the fundamental elements of nanoscale solar cell technology. Citation: Tiny tech, big results: Quantum dot solar cells increase solar conversion efficiency (2011, August 2) retrieved 18 August 2019 from https://phys.org/news/2011-08-tiny-tech-big-results-quantum.html It follows, then, that CQD photovoltaics are amenable to significant scaling. “Even in the R&D lab,” Sargent points out, “we synthesize enough colloidal quantum dots in each run to cover a square meter of surface with a complete light absorber. Work remains to be done in developing the final thin-film-processing approaches that are compatible with large-area roll-to-roll processing.”Sargent notes that there is some overlap with Stanford University’s Photon Enhanced Thermionic Emission (PETE) research. PETE increases the energy conversion efficiency of thermionic devices (which convert heat to electricity) implemented as topping cycles for solar thermal systems, thereby potentially doubling photovoltaic conversion ratios. “What our approaches have in common is splitting the spectrum into two components – the higher-energy visible and the lower-energy but abundant-photon-fluence, or flux, infrared. That said,” he stresses, “there are also important differences: our approach does not require optical concentration, while PETE does. Also, ours works best at typical ambient temperatures; PETE requires that the cathode operate at 600-800ºC.” Sargent sees the next steps in the team’s research as being “focused on the task of enhancing electron and hole transport inside colloidal quantum dot films with the goal of making low-temperature-processed, flexible, low-cost solar cells that exceed 10% solar power conversion efficiency.”last_img read more

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Hitachi Maxell announces Air Voltage wireless charger for iPad2

first_img 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. © 2011 PhysOrg.com Citation: Hitachi Maxell announces ‘Air Voltage’ wireless charger for iPad2 (2011, September 30) retrieved 18 August 2019 from https://phys.org/news/2011-09-hitachi-maxell-air-voltage-wireless.html Three in China convicted for iPad2 design theft While technically not a wireless system as the term is customarily used, the system does allow users to recharge their iPad2 without having to plug anything in. Instead, the base itself is plugged in, as is done with say, a wireless router and it then charges the device using the “electric field coupling method” which is where electricity is moved from the charger to the device via the creation of an electric field that is generated between the two. Electrodes in the cover pick up the electricity and transfer it to the AC input port on the iPad2. The system has been developed for Hitachi Maxwell by Murata Manufacturing Co Ltd. Because the electricity is passed via the air, it is a wireless system, despite the fact that it appears to the user to be otherwise since they have to place their iPad2 on the base in order for it t be recharged.The cover (black or white) comes in two parts, top and bottom. To put it on, the iPad2 is slipped into the bottom part then the top half is slipped on till the two parts join. The back is a full cover, and the front looks like a picture frame. The whole works is then set on the base either horizontally or vertically. The iPad2 can be used while it is being recharged just as when using a regular plug-in AC adaptor.Though a price has not yet been set for the Air Voltage, industry analysts expect it will sell for around $200, though initially it will only be for sale in Japan. What’s not clear is whether users will be willing to accept a change of appearance to their brilliantly designed iPad2, by placing a cover on it, merely for the convenience of not having to plug it in to recharge it. Explore further (PhysOrg.com) — Hitachi Maxell Ltd has announced that it will release the “Air Voltage” a system for recharging the Apple iPad2 sans cable on November 25th. Comprised of the “energy stand” and “energy cover” for the iPad2, the two pieces together replace the AC adapter that comes with the iPad2. To recharge the iPad2, a user slips the energy cover onto it then sets the whole works on the stand where it is recharged in the normal amount of time, i.e. about three hours for a full charge.last_img read more

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Quantum shortcuts cannot bypass the laws of thermodynamics

first_imgCredit: CC0 Public Domain More information: Steve Campbell and Sebastian Deffner. “Trade-Off Between Speed and Cost in Shortcuts to Adiabaticity.” Physical Review Letters. DOI: 10.1103/PhysRevLett.118.100601Also at arXiv:1609.04662 [quant-ph] Now in a new study, physicists have shown that quantum shortcuts are subject to a trade-off between speed and cost, so that the faster a quantum system evolves, the higher the energetic cost of implementing the shortcut. In accordance with the laws of thermodynamics, an infinitely fast speed would be impossible since it would require an infinite amount of energy.The physicists, Steve Campbell at Queen’s University Belfast in the UK and the University of Milan in Italy, along with Sebastian Deffner at the University of Maryland Baltimore County in the US, have published a paper on the trade-off between cost and speed in quantum shortcuts in a recent issue of Physical Review Letters.”Some recently proposed methods to control quantum systems, called shortcuts to adiabaticity (STA), appear to be energetically for free, and even more concerning there was nothing to say they couldn’t be achieved in vanishingly small times,” Campbell told Phys.org. “That something wasn’t quite right led us to more explicitly consider what happens when these techniques are applied.”To do this, the scientists applied the quantum speed limit—a fundamental upper bound on the speed at which a quantum system can operate, which arises due to the Heisenberg uncertainty principle. Since the quantum speed limit is a consequence of this fundamental principle, it must apply to all STAs, and so it should prohibit them from operating in arbitrarily short times.”By calculating the quantum speed limit, we showed that the faster you want to manipulate a system using an STA, the higher the thermodynamic cost,” Campbell. “Moreover, instantaneous manipulation is impossible since it would require an infinite energy to be put in.” As the scientists explained, the results are not particularly surprising, just something that took time to figure out.”I believe this is another case of ‘if something seems too good to be true, it typically is,'” Deffner said. “There was probably a general sense in the community that one will have to quantify the cost. We were just the first to work it out.”To demonstrate the usefulness of this trade-off, the physicists applied it to two practical systems. The first is harmonic oscillators, which have a wide range of uses, including in tests of quantum thermodynamics. The second is the Landau-Zener model, which has applications in adiabatic quantum computing, as used in the D-Wave machine.In both models, the tradeoff places practical limits on the ultimate speed-up of these systems offered by STAs. The scientists expect that these limitations will help guide the design and implementation of these and other quantum systems in the future.”We would also like to look into the other techniques for STA that have been developed, and see whether we can find similar trade-offs,” Deffner said. “Another important route will be to generalize our work to non-standard quantum mechanics, such as Dirac materials and nonlinear systems.” © 2017 Phys.org Journal information: Physical Review Letters Physicists extend quantum machine learning to infinite dimensionscenter_img Citation: Quantum shortcuts cannot bypass the laws of thermodynamics (2017, March 16) retrieved 18 August 2019 from https://phys.org/news/2017-03-quantum-shortcuts-bypass-laws-thermodynamics.html Explore further (Phys.org)—Over the past several years, physicists have developed quantum shortcuts that speed up the operation of quantum systems. Surprisingly, some of these shortcuts theoretically appear to enable systems to operate nearly instantaneously while using no extra energy—a clear violation of the second law of thermodynamics. Although physicists have known that something is amiss, so far the solution to this predicament has been unclear. 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

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4000yearold woodhenge discovered in Yorkshire might have been a sauna

first_img © 2018 Phys.org 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. A team of researchers led by freelance archaeologist John Tibbles has found evidence suggesting that a woodhenge discovered in Yorkshire several months ago might have been used for sacrifices, or perhaps as a sauna. Tibbles spoke to the Yorkshire Post recently, offering up details of the site and his ideas on its purpose. The woodhenge was discovered at Little Catwick Quarry in Yorkshire, near a town called Hornsea, and was part of a site that has been under excavation since 1992. Even after surface excavation, however, it is still difficult to make out the configuration of the site—from the air, however, things become clearer. It forms a large circle with rectangles at its edges and a pile of small stones at its middle—the circle is made by a ditch and an outer sand bank. The site has been dated to approximately 4,000 years ago, putting it at the edge between the Neolithic and Bronze Age. Work done at the site, Tibbles reports, showed that the rectangles at the edges were bases for what appeared to be wood pole buildings or simple benches. There were also two entrances, one on the northwest side, the other on the southeast side of the circle.The pit at the center of the site has been the object of much study—it’s a hole filled with burnt stones that appear to have been carried to the site after heating. Similar stones were found buried near the entrances. Tibbles suggests that the stones indicate the possibility of rituals, possibly for cremation, in which bodies were burned and then removed. He notes that it seems logical to consider that there might be a link between the site and the site at Sandsfield, which is just a mile away and has a cemetery with a ring ditch and 37 urns, and dates back to around the same time period.Tibbles suggests there is also another possibility—that the site was actually used as a large sauna. Heated rocks could be carried in, he notes, followed by some water to toss on them for steam. The site could be a sweat lodge similar to those used by early American Indians.The researchers plan to continue digging in the spring as the quarry is extended.center_img Superhenge turns out to be giant circle of chalk-filled post holes Citation: 4000-year-old woodhenge discovered in Yorkshire might have been a sauna (2018, January 5) retrieved 18 August 2019 from https://phys.org/news/2018-01-year-old-woodhenge-yorkshire-sauna.html Aerial picture of the excavations at Little Catwick Quarry. Credit: John Tibbleslast_img read more

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Harmonic oscillators most classicallike state exhibits nonclassical behavior

first_img The physicists, S. Bose at University College London; D. Home at the Bose Institute in Kolkata, India; and S. Mal at the S.N. Bose National Center for Basic Science in Kolkata, India, have published a paper on the nonclassicality of a harmonic oscillator’s most classical-like state in a recent issue of Physical Review Letters.”Einstein’s intriguing and much debated question ‘Is the moon there when nobody looks at it?’ concerns the everyday notion of macrorealism, which lies at the core of the classical worldview,” Home told Phys.org. “To put it simply, macrorealism means that, at any instant, a system is in a definite state having definite properties, irrespective of any observation/measurement. “In this context, our work opens up a novel direction for testing macrorealism by showing that the quantum mechanical violation of macrorealism is testable for a system like a harmonic oscillator, which has a well-defined classical description and is initially in a state which is the most classical-like of all quantum states, the harmonic oscillator coherent state.”In their work, the physicists proposed a test involving a linear harmonic oscillator that can be implemented using a macroscopic particle that oscillates between two sides (left and right) of a harmonic well. The two sides of the well correspond to the particle’s two possible states. By performing a noninvasive measurement, it’s possible to determine which of the two states the particle is in without affecting its future behavior.The researchers then used a test in which a particle’s state is measured at two different times in four different runs of the experiment. By making two assumptions—that the particle obeys realism and that the measurements are non-invasive—restrictions can be placed on the possible outcomes of these measurements, giving rise to a testable prediction in the form of a Leggett-Garg inequality. The main result of the study is that, in this example, the quantum mechanical predictions violate the Leggett-Garg inequality even for particles with large mass. This implies that either the particle does not obey realism or that the measurements are invasive. But as the physicists ruled out the latter by proposing to use a measurement procedure called the negative result measurement, which is specifically designed to be noninvasive, the results indicate that the particle does not obey realism, a sign of nonclassical behavior.As the physicists explained, theoretically it’s possible for a particle of any mass to violate realism using this test, up to and including large macroscopic objects. The researchers argue that it may be experimentally feasible to use optically trapped nano-objects with masses of a million to a billion times heavier than the hydrogen atom to violate the Leggett-Garg inequality, thereby demonstrating violation of macrorealism for large masses. On the other hand, it should be much easier to experimentally demonstrate the violation for smaller masses since tests with larger masses require experimentally difficult-to-attain values for other parameters, such as the momentum. By the same token, if these other parameters are fixed, then an object may be too large to violate the inequality, indicating a lack of nonclassical behavior.Although there are other methods of testing for nonclassical behavior, the physicists believe that the new test is arguably the simplest method yet. The researchers expect that the test can be implemented using currently available, cutting-edge technology. Already, a group at the University of Southampton has plans to experimentally implement the test in the coming months. “The experimental complexity is seemingly far less than that for competitive matter wave interferometry experiments following the same goal, namely to test the possible macroscopic limits of quantum mechanics and the validity of the notion of macrorealism,” Home said. Easing uncertainty Showing just how blurry the boundary is between the quantum and classical worlds, physicists in a new study have theoretically demonstrated that a macroscopic oscillating object initially in a classical-like coherent state can exhibit nonclassical behavior—namely, it can violate the classical notion of realism by not having a single definite state at any given moment. Instead, the oscillator has one of two states with a certain probability, as theoretically shown by non-invasive measurements of the oscillator’s position at different times. Explore further In the proposed experiment to test the violation of macrorealism, a particle oscillates between two sides of a harmonic well. Credit: S. Bose et al. ©2018 American Physical Society © 2018 Phys.orgcenter_img More information: S. Bose, D. Home, and S. Mal. “Nonclassicality of the Harmonic-Oscillator Coherent State Persisting up to the Macroscopic Domain.” Physical Review Letters. DOI: 10.1103/PhysRevLett.120.210402 Journal information: Physical Review Letters Citation: Harmonic oscillator’s most ‘classical-like’ state exhibits nonclassical behavior (2018, June 14) retrieved 18 August 2019 from https://phys.org/news/2018-06-harmonic-oscillator-classical-like-state-nonclassical.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

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Canadian orphanage volunteer convicted of sexual assault

first_imgA Nepalese court convicted a Canadian orphanage volunteer on Sunday of sexually abusing a 15-year-old disabled boy and sentenced him to seven years in prison, an official said.Ernest Fenwick MacIntosh, 71, arrived in the Himalayan nation on a tourist visa last August and approached the Jesuit-run St Xavier’s Social Service Center for homeless children with an offer of donations.A court statement released after his conviction said MacIntosh repeatedly molested the boy, who has only one arm and was living in the orphanage, after offering him gifts and money and promising to pay for a prosthetic arm. “He has been proven guilty and sentenced to seven years in jail… the boy’s testimony and results of a polygraph test provided strong evidence against him,” court spokesman Kaushaleshwor Gyawali told AFP. Police arrested MacIntosh after the boy filed a complaint on December 19.last_img read more

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Mamata raises voice against Internet misuse

first_imgKolkata: On the occasion of the World Telecommunication and Information Society Day on Thursday, West Bengal Chief Minister Mamata Banerjee said that social media should not be used to spread negativity. “In this age, we must not use social media and the Internet to spread negativity or to malign others or spread fake news,” read Banerjee’s official Twitter post.Banerjee’s tweet resonates with the theme of World Telecommunication and Information Society Day 2018 — “Enabling the positive use of Artificial Intelligence for All”. Also Read – Heavy rain hits traffic, flightsThe World Telecommunication and Information Society Day (WTISD) is observed every year on May 17 which marks the anniversary of the signing of the first International Telegraph Convention and the creation of the International Telecommunication Union.The purpose is to raise awareness of the possibilities that the use of Internet and other information and communication technologies (ICT) can lead to, besides bridging the digital divide.last_img read more

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Reflective of joy within

first_imgColors of joy is the solo art show by Neelam Mansharamani that commenced on March 30 at the Hungarian Information and Cultural Centre. The show was inaugurated by KL Ganju, Honorary Consul General, Consulate of Union of Comoros, Tibor Kovacs, Director, Hungarian Information and Cultural Centre and Subha Rajan , Head External Affairs , Confederation of Indian Industry and a motivational thinker Paramjit S Kochar, art curator and Writer. An ardent visual artist then, Neelam Mansharamani, a well read and a well bred young girl started her career in a reputed advertising agency and topped it up with a few assignments in a couple of Embassies / Diplomatic Missions.  She paints the canvasses, drawing inspiration from the odds of her own life. Also Read – ‘Playing Jojo was emotionally exhausting’Wordsworth said, “Poetry is the spontaneous overflow of the deep passions in a person”. “I feel that Art is Visual Poetry. As a poet expresses his feelings in words, an artist conveys her mind by virtue of sketches, hues and works”, says Neelam.In her series titled Colors of Joy , Neelam has rightly portrayed her thoughts, evolved out of her own life of being a painter, a creator, an actor, a director, a character and above all a mother.last_img read more

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Adorned Dilli Haats welcome Teej Festival

first_imgA festival of feasts and celebrations, Teej marks the welcome of the monsoon season during the month of ‘Shravan’ or ‘Saawan.’  The festival is primarily dedicated to Goddess Parvati and her union with Lord Shiva. Hence, it is also said to be an auspicious occasion for married women to be blessed with marital bliss.One can witness the celebration of annual Teej festival at the three Dilli Haats of the city where it is being organised. One of the highlighting features of the Teej Festival is the coming together of women enjoying the Teej Jhula, a swing hung from trees in villages and towns.  Also Read – ‘Playing Jojo was emotionally exhausting’The celebrations are accompanied by dancing, singing folk songs, dressing up in colourful outfits, ceremonial art of applying Mehendi and sharing festive delicacies. Special Mehendi stalls put up at all the three Dilli Haats will offer hennaapplication with exclusive designs. Dilli Haat Janakpuri would be hosting competitions of making bindi, rangoli and mehendi art with an added attraction of the Teej Jhula and camel rides for kids. The evenings would be lightened up with cultural programmes specially hosted by Rajasthan Tourism showcasing the charm of the state’s folk dance and music. •       Dilli Haat, INA  When: August 16 —17, Timings 10:30 am – 10:00 pm•       Dilli Haat, Pitampura: When: August 14 – 16, Timings 11:00 am – 9:30 pm•       Dilli Haat, Janakpuri: When August 15 – 18, Timings 11:00 am – 10:00 pmlast_img read more

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