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  • richardmitnick 11:57 am on September 14, 2019 Permalink | Reply
    Tags: , , , , , , , , , University of Melbourne   

    From from the University of Melbourne and Australia’s ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) via COSMOS: “The hunt for a 12-billion-year-old signal” 

    From

    u-melbourne-bloc

    From University of Melbourne

    and

    arc-centers-of-excellence-bloc

    From ARC Centres of Excellence

    via

    10 September 2019
    Nick Carne

    1
    In this image the Epoch of Reionization, neutral hydrogen, in red, is gradually ionised by the first stars, shown in white.
    Paul Giel and Simon Mutch / UNIVERSITY OF MELBOURNE DARK-AGES REIONIZATION AND GALAXY OBSERVABLES FROM NUMERICAL SIMULATIONS (DRAGONS) PROGRAM

    Astronomers believe they are closing in on a signal that has been travelling across the Universe for 12 billion years.

    In a paper soon to be published in The Astrophysical Journal, an international team reports a 10-fold improvement on data gathered by the Murchison Widefield Array (MWA), a collection of 4096 dipole antennas set in the remote hinterland of Western Australia.

    SKA Murchison Widefield Array, Boolardy station in outback Western Australia, at the Murchison Radio-astronomy Observatory (MRO)

    The MWA was built specifically to detect electromagnetic radiation emitted by neutral hydrogen – a gas that made up most of the infant Universe in the period when the soup of disconnected protons and neutrons spawned by the Big Bang started to cool down.

    Eventually those atoms began to clump together to form the very first stars, initiating the major phase in the evolution of the Universe known as the Epoch of Reionization, or EoR.

    2
    Epoch of Reionization. Caltech/NASA

    “Defining the evolution of the EoR is extremely important for our understanding of astrophysics and cosmology,” says research leader Nichole Barry from the University of Melbourne and Australia’s ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D).

    “So far, though, no one has been able to observe it. These results take us a lot closer to that goal.”

    The neutral hydrogen that dominated space and time before and in the early period of the EoR radiated at a wavelength of approximately 21 centimetres.

    Stretched now to somewhere above two metres because of the expansion of the Universe, the signal persists – and detecting it remains the theoretical best way to probe conditions in the early days of the Cosmos.

    But that’s difficult to do, the researchers say, as the signal is old and weak and there are a lot of other galaxies in the way.

    That means the signals recorded by the MWA and other EoR-hunting devices, such as the Hydrogen Epoch of Reionisation Array (HERA) in South Africa and the Low Frequency Array (LOFAR) in The Netherlands, are extremely messy.

    UC Berkeley Hydrogen Epoch of Reionization Array (HERA), South Africa

    ASTRON LOFAR Radio Antenna Bank, Netherlands

    Using 21 hours of raw data, Barry and colleagues explored new techniques to refine analysis and exclude consistent sources of signal contamination, including ultra-faint interference generated by radio broadcasts on Earth.

    The result was a level of precision that significantly reduced the range in which the EoR may have begun, pulling in constraints by almost an order of magnitude.

    “We can’t really say that this paper gets us closer to precisely dating the start or finish of the EoR, but it does rule out some of the more extreme models,” says co-author Cathryn Trott, from Australia’s Curtin University.

    “That it happened very rapidly is now ruled out. That the conditions were very cold is now also ruled out.”

    The research was conducted by researchers from a number of institutions in Australia and New Zealand, in collaboration with Arizona State University, Brown University and MIT in the US, Kumamoto University in Japan, and Raman Research Institute in India.

    See the full article here .


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    Please help promote STEM in your local schools.

    Stem Education Coalition

    The objectives for the ARC Centres of Excellence are to:

    undertake highly innovative and potentially transformational research that aims to achieve international standing in the fields of research envisaged and leads to a significant advancement of capabilities and knowledge
    link existing Australian research strengths and build critical mass with new capacity for interdisciplinary, collaborative approaches to address the most challenging and significant research problems
    develope relationships and build new networks with major national and international centres and research programs to help strengthen research, achieve global competitiveness and gain recognition for Australian research
    build Australia’s human capacity in a range of research areas by attracting and retaining, from within Australia and abroad, researchers of high international standing as well as the most promising research students
    provide high-quality postgraduate and postdoctoral training environments for the next generation of researchers
    offer Australian researchers opportunities to work on large-scale problems over long periods of time
    establish Centres that have an impact on the wider community through interaction with higher education institutes, governments, industry and the private and non-profit sector.

    u-melbourne-campus

    The University of Melbourne (informally Melbourne University) is an Australian public research university located in Melbourne, Victoria. Founded in 1853, it is Australia’s second oldest university and the oldest in Victoria. Times Higher Education ranks Melbourne as 33rd in the world, while the Academic Ranking of World Universities places Melbourne 44th in the world (both first in Australia).

    Melbourne’s main campus is located in Parkville, an inner suburb north of the Melbourne central business district, with several other campuses located across Victoria. Melbourne is a sandstone university and a member of the Group of Eight, Universitas 21 and the Association of Pacific Rim Universities. Since 1872 various residential colleges have become affiliated with the university. There are 12 colleges located on the main campus and in nearby suburbs offering academic, sporting and cultural programs alongside accommodation for Melbourne students and faculty.

    Melbourne comprises 11 separate academic units and is associated with numerous institutes and research centres, including the Walter and Eliza Hall Institute of Medical Research, Florey Institute of Neuroscience and Mental Health, the Melbourne Institute of Applied Economic and Social Research and the Grattan Institute. Amongst Melbourne’s 15 graduate schools the Melbourne Business School, the Melbourne Law School and the Melbourne Medical School are particularly well regarded.

    Four Australian prime ministers and five governors-general have graduated from Melbourne. Nine Nobel laureates have been students or faculty, the most of any Australian university.

     
  • richardmitnick 10:33 am on July 29, 2019 Permalink | Reply
    Tags: , SABRE (Sodium-iodide with Active Background Rejection), , , University of Melbourne   

    From Swinburne University and University of Melbourne: “Swinburne goes underground in search for dark matter” 

    Swinburne U bloc

    From Swinburne University

    and

    u-melbourne-bloc

    University of Melbourne

    29 July 2019

    Swinburne
    Media enquiries
    0455 502 999
    media@swinburne.edu.au

    Melbourne Media contact
    Emma Sun
    emma.sun@unimelb.edu.au
    +61 466 133 480

    1
    Swinburne Associate Professor Alan Duffy (left) at the site of the future Stawell Underground Physics Laboratory, where Minister for Regional Development Jaclyn Symes (centre) announced the funding.

    Swinburne University of Technology will be a key institution in the international project to explore and search for dark matter, following an announcement that Victoria’s state government will contribute $5 million to build the Stawell Underground Physics Laboratory.

    The funding has been announced by Victoria’s state Minister for Regional Development, Jaclyn Symes, and matches the federal government’s funding commitment confirmed in April.

    The laboratory will be built one kilometre underground, within the Stawell Gold Mine, as a bespoke excavated cavity 30 metres long, 10 metres wide and 10 metres high. It will provide ultra-low background research facilities (free from the particles that form background radiation) needed in the ground-breaking search for dark matter.

    Swinburne is one of six international institutes involved in the project, led by the University of Melbourne.

    The search for dark matter

    Swinburne astrophysicist, Associate Professor Alan Duffy, says understanding dark matter is one of the greatest scientific challenges of this century.

    “Astronomers have seen the movement of stars pulled by the gravity of an unseen companion. We now think that this unseen companion, dark matter, makes up five times more of the Universe than everything we can see combined,” he says.

    “The attention of the world’s physicists will now be on regional Victoria as a leader in the search for dark matter.”

    Associate Professor Duffy says that the establishment of Stawell as a physics research hub will also provide local education benefits.

    “This Lab will undoubtedly inspire local students to study physics in school and at university, but it also means that if they want to be part of a global scientific experiment, they can do that right here in Stawell.”

    The project is expected to deliver economic value to the region of $180.2 million in its first ten years, and support ongoing jobs.

    Ms Symes says: “With nearly 80 ongoing jobs connected to the Lab, this project will diversify Stawell’s economy – attracting a new highly-skilled workforce to the region to live and work.”

    University of Melbourne project leader, Professor Elisabetta Barberio, says the laboratory will be home to important scientific experiments.

    “The investment by both the state and federal governments ensure the Lab is large enough to host dark matter experiments as well as everything from fundamental cancer research into how radiation affects cells growing, to creating new ultra-sensitive detectors and novel geological exploration techniques,” she says.

    The project is a collaboration between six international partners. It will be led by the University of Melbourne alongside Swinburne, the University of Adelaide, the Australian National University, the Australian Nuclear Science and Technology Organisation (ANSTO) and the Italian National Institute for Nuclear Physics.

    The Southern Hemisphere’s first dark matter detector

    Swinburne is heavily involved in building the largest experiment to take place in the Stawell Underground Physics Laboratory – SABRE (Sodium-iodide with Active Background Rejection), which is the Southern Hemisphere’s first dark matter detector.

    The vessel will be arriving at Swinburne’s Wantirna campus in August, where it will undergo a rigorous assembly and electronics fit-out process, including leak testing and internal reflective surface coating. Only once the international team is satisfied that it meets the exacting standards for this kind of precision experiment will it move to the underground laboratory where the search for dark matter can begin.

    See the full article here .

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    Please help promote STEM in your local schools.

    Stem Education Coalition

    University of Melbourne

    Swinburne U Campus

    Swinburne is a large and culturally diverse organisation. A desire to innovate and bring about positive change motivates our students and staff. The result is in an institution that grows and evolves each year.

     
  • richardmitnick 3:44 pm on February 23, 2017 Permalink | Reply
    Tags: Magnetic resonance imaging, , University of Melbourne   

    From MIT Tech Review: “This Microscope Reveals Human Biochemistry at Previously Unimaginable Scales” 

    MIT Technology Review
    M.I.T Technology Review

    February 23, 2017

    1

    Magnetic resonance imaging is one of the miracles of modern science. It produces noninvasive 3-D images of the body using harmless magnetic fields and radio waves. And with a few additional tricks, it can also reveal details of the biochemical makeup of tissue.

    1
    Atomic-scale MRI holds promise for new drug discovery | The Melbourne Newsroom

    That biochemical trick is called magnetic resonance spectroscopy, and it is a powerful tool for physicians and researchers studying the biochemistry of the body, including metabolic changes in tumors in the brain and in muscles.

    But this technique is not perfect. The resolution of magnetic resonance spectroscopy is limited to length scales of about 10 micrometers. And there is a world of chemical and biological activity at smaller scales that scientists simply cannot access in this way.

    So physicians and researchers would dearly love to have a magnetic resonance microscope that can study body tissue and the biochemical reactions within it at much smaller scales.

    Today, David Simpson and pals at the University of Melbourne in Australia say they have built a magnetic resonance microscope with a resolution of just 300 nanometers that can study biochemical reactions on previously unimaginable scales. Their key breakthrough is an exotic diamond sensor that creates magnetic resonance images in a similar way to a light sensitive CCD chip in a camera.

    Magnetic resonance imaging works by placing a sample in a magnetic field so powerful that the atomic nuclei all become aligned; in other words, they all spin the same way. When these nuclei are zapped with radio waves, the nuclei become excited and then emit radio waves as they relax. By studying the pattern of re-emitted radio waves, it is possible to work out where they have come from and so build up a picture of the sample.

    The signals also reveal how the atoms are bonded to each other and the biochemical processes at work. But the resolution of this technique is limited by how closely the radio receiver can get to the sample.

    Enter Simpson and co, who have built an entirely new kind of magnetic resonance sensor out of diamond film. The secret sauce in this sensor is an array of nitrogen atoms that have been embedded in a diamond film at a depth of about seven nanometers and about 10 nanometers apart.

    Nitrogen atoms are useful because when embedded in diamond, they can be made to fluoresce. And when in a magnetic field, the color they produce is highly sensitive to the spin of atoms and electrons nearby or, in other words, to the local biochemical environment.

    So in the new machine, Simpson and co place their sample on top of the diamond sensor, in a powerful magnetic field and zap it with radio waves. Any changes in the state of nearby nuclei causes the nitrogen array to fluoresce in various colors. And the array of nitrogen atoms produces a kind of image, just like a light sensitive CCD chip. All Simpson and co do is monitor this fireworks display to see what’s going on.

    To put the new technique through its paces, Simpson and co study the behavior of hexaaqua copper(2+) complexes in aqueous solution. Hexaaqua copper is present in many enzymes which use it to incorporate copper in metalloproteins. However, the distribution of copper during this process, and the role it plays in cell signaling, is poorly understood because it is impossible to visualize in vivo.

    Simpson and co show how this can now be done using their new technique, which they call quantum magnetic resonance microscopy. They show how their new sensor can reveal the spatial distribution of copper 2+ ions in volumes of just a few attoLitres and at high resolution. “We demonstrate imaging resolution at the diffraction limit (~300 nm) with spin sensitivities in the zeptomol (10‐21) range,” say Simpson and co. They also show how the technique reveals the redox reactions that the ions undergo. And they do all this at room temperature.

    That’s impressive work that has important implications for the future study of biochemistry. “The work demonstrates that quantum sensing systems can accommodate the fluctuating Brownian environment encountered in ‘real’ chemical systems and the inherent fluctuations in the spin environment of ions undergoing ligand rearrangement,” says Simpson and co.

    That makes it a powerful new tool that could change the way we understand biological processes. Simpson and co are optimistic about its potential. “Quantum magnetic resonance microscopy is ideal for probing fundamental nanoscale biochemistry such as binding events on cell membranes and the intra‐cellular transition metal concentration in the periplasm of prokaryotic cells.”

    Ref: arxiv.org/abs/1702.04418: Quantum Magnetic Resonance Microscopy

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The mission of MIT Technology Review is to equip its audiences with the intelligence to understand a world shaped by technology.

     
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