Events: Centre: Physics Centre events at Chalmers University of TechnologyTue, 22 May 2018 14:11:19 +0200 thesis review: Sophie Viaene<p>PJ, lecture hall, Fysik Origo, Fysik</p><p>​Sophie used techniques from general relativity, condensed matter physics, and nonlinear dynamics to describe advanced electromagnetic phenomena inside structured metamaterials. Title: Exploring metamaterial horizons:  New concepts and geometrical tools for the description of advanced electromagnetic phenomena.</p><h4 class="chalmersElement-H4">Abstract:</h4> <div>Einstein’s theory of general relativity has dramatically changed our world view by describing gravity as an intrinsic deformation of space and time. About fifteen years ago, John Pendry and Ulf Leonhard had the intriguing idea to emulate the behaviour of light in a deformed space by making use of carefully designed artificial metamaterials, which consist of elemental structures that are much smaller than the wavelength of light. To this end, they developed a technique known as transformation optics, which determines the metamaterial properties that are required to reproduce the Maxwell equations on a deformed space time. The required metamaterial properties are implemented by optimizing the shape, the composition, and the spacing of metamaterial structures and have resulted in several impressive, but often intuitive devices. For example, metamaterials may guide light around an object so that is becomes invisible.</div> <div>Thanks to rapidly advancing fabrication methods, the scope of metamaterial research has extended towards reconfigurable, two-dimensional, and/or quantum applications. However, reconfigurable, two-dimensional, and/or quantum metamaterial properties have not yet been described in an intuitive way. The first part of the thesis introduces new concepts to describe reconfigurable metamaterials with properties that are determined by an external control such as an electric signal or light. The intuitive description of reconfigurable materials with effective gauges and tools from nonlinear dynamics is important, because it shows to what extent metamaterials may improve active photonic devices. In the second part of the thesis, the geometrical tools of transformation optics are extended so that they apply to two-dimensional metamaterials and quantum metamaterials. This has resulted in designs of metamaterial layers that deform light flows along their surface and in light sources with controlled emission rates and frequencies inside a metamaterial black hole. By describing the behaviour of light inside reconfigurable metamaterials, two-dimensional metamaterials, and quantum metamaterials in an intuitive way, this thesis paves the way to novel metamaterial designs that will contribute to future light-based applications.</div> Nugroho, Physics<p>PJ, lecture hall, Fysik Origo, Fysik</p><p>Title of thesis: Nanoplasmonic Alloy Hydrogen Sensors A Quest for Fast, Sensitive and Poisoning-Resistant Hydrogen Detection</p><h4 class="chalmersElement-H4">Abstract:</h4> <div>Imagine driving a car for hours, travelling along the beautiful coasts of Sweden, and what is coming out of the exhaust pipe are not toxic and polluting gases but only water. How fun and relieving would it be? This scenario may sound like imagination but, in fact, it is not. It happens now as you read this, with the rise of a hydrogen energy system. Hydrogen, the smallest and most abundant element in the universe, is wonderful. It carries three times more energy than gasoline of the same mass and possesses high energy conversion efficiency. Even better, hydrogen can be produced from water and therefore enables a truly sustainable energy cycle, free from polluting and greenhouse gas emissions.</div> <div> </div> <div>With these fantastic facts, one may then wonder: “Why don’t we see it being used more often now?” Apparently, there are a lot of reasons. To fully integrate the concept into our lives, there are still a lot of technological advances that have to be accomplished in multiple sectors, from the creation of hydrogen gas, its storage, to its distribution and usage. Most importantly, in each of these sectors, the process has to be done safely as hydrogen is actually a quite dangerous gas: it is flammable! Just a mere 4% of hydrogen gas in a room is enough to start a fire if a tiny spark ignites the hydrogen-air mixture. In fact, the trauma of the Hindenburg disaster in 1937, where a zeppelin balloon filled with hydrogen caught fire and crashed, killing 35 people, hinders to some extent the wide use of hydrogen fuel still today. To move forward, it is thus imperative to have a hydrogen detection system to signal a leak before a flammable hydrogen concentration is reached. As a guideline for this development, many institutions and stakeholders of a hydrogen energy system have released demanding performance standards for hydrogen sensors. In general, they have to be fast, sensitive and stable for many years of application.</div> <div> </div> <div>Current hydrogen sensors mostly use palladium (often mixed with gold to produce “white gold”) since it can absorb a lot of hydrogen spontaneously, accompanied by the change in its characteristics. However, in this respect palladium hydrogen sensors are commonly characterized by slow response with low sensitivity. Even worse, palladium’s ability to absorb hydrogen disappears when it is exposed to some pollutant gases such as carbon monoxide and nitrogen dioxide, which we find readily in the (urban) air. To fulfill the requirements above, finding new type of sensors with novel materials is thus necessary.</div> <div> </div> <div>In this thesis I present a hydrogen-sensing platform using light and extremely small particles of alloys of palladium and other metals. To do so, I would like to bring the reader into a world thousand times smaller than a strand of hair, a scale where materials may behave significantly different than how they are commonly known to. For example, in this size regime, palladium particles exhibit a color that depends on their shape and size. I will discuss how these small palladium alloy particles are produced and how they absorb hydrogen, which later modifies their color. Finally I show how we can make use of this phenomenon to realize an optical hydrogen sensor by measuring the color change induced by hydrogen. By combining palladium with other metals such as gold and copper, as well as covering it with different types of polymers (one is the polymer we use in our non-stick frying pans!), I created a fast, sensitive and stable hydrogen sensor. As the key highlight of this thesis, I succeeded to detect as low as 1 hydrogen molecule per 1000 gas molecules in less than 1 second, that is, the fastest hydrogen sensor in the world! And best of all, it still works even under exposure to carbon monoxide and nitrogen dioxide. So sit back, get a drink and enjoy the reading!</div>é-Carmelo.aspx by José Carmelo<p>Lunchroom, Soliden floor 3</p><p>Seminar by Professor José Carmelo, University of Minho, Portugal Title: Effects of long-range interactions on spectral properties of low-dimensional systems</p><h4 class="chalmersElement-H4">Abstract:</h4> <div>A transformation that accounts for the universality found in Ref. [1] concerning the spectral functions of both integrable and non-integrable one-dimensional (1D) correlated systems is used to generate from the pseudofermion dynamical theory of the integrable 1D Hubbard model [2], which relies on a suitable rotated-electron representation [2,3], a corresponding renormalized theory with additional electron finite-range interactions [4]. An improved version of the latter theory that accounts for long-range interactions is used to describe the experimental spectral lines in the angle resolved photoemission spectroscopy (ARPES) of two low-dimensional systems: The quantum line defects in the two-dimensional van der Waals layered semiconductor MoSe2 [4] and an anisotropic InSb(001) surface covered with Bi [5]. The theoretical predictions refer to high-energy windows in the vicinity of the peaks of the observed spectral lines. For the parameters values for which the predicted peaks distribution agrees with that in the ARPES images, the low-energy power-law density of states suppression exponent α is given by α ≈ 0.72−078 for the MoSe2 line defects [4] and α ≈ 0.60 − 0.70 for Bi/InSb(001) [5], in agreement with their experimental uncertainties.</div> <div>(For the 1D Hubbard model, α &lt; 1/8).</div> microscope workshop<p></p><p>​​On 24-25 May Chalmers Materials Analysis Laboratory (CMAL) will host a Raman microscope workshop that is organised by CMAL together with WITec and Kimmyphotonics.</p><img class="chalmersPosition-FloatRight" src="/SiteCollectionImages/Institutioner/F/Blandade%20dimensioner%20inne%20i%20artikel/SensitivityBanner230x320_1.jpg" width="177" height="155" alt="" style="margin:5px" />The workshop will highlight new trends and perspectives in Raman imaging and give a detailed introduction to the operational principles and instrumental configurations relevant to confocal Raman imaging. It will also be possible to register for a hands-on demonstration of the instrument. <br />The workshop is free of charge. <br /><br /><strong><font color="#5b97bf"></font></strong><span><a href=""><span><span style="display:inline-block"></span></span></a></span> Reginald Penner and Laura Lechuga<p>PJ, lecture hall, Fysik Origo, Fysik</p><p>Seminar 1: 10.00-10.40 Biosensors for early cancer detection based upon electrical interfaces to virus particles. Professor Reginald Penner, University of California, Irvine, USA Seminar 2: 10.40-11.20 Nanophotonic biosensor platforms for ultrasensitive bioanalysis. Professor Laura Lechuga, Catalan Institute of Nanoscience and Nanotechnology, Barcelona, Spain</p><h4 class="chalmersElement-H4">Abstract:</h4> <div><strong>Seminarium</strong><strong> 1:</strong> Biosensor technologies that enable the rapid measurement of disease biomarkers in unprocessed biological samples, including blood, urine, saliva, and cerebrospinal fluids, remain elusive and highly sought after. The ultimate goal are devices that can be used with minimal training by physicians and patients to provide actionable information at the point-of-care (PoC). In addition to simplicity, analysis speed and sensitivity are critically important metrics for PoC biosensors but the technology must also provide for sensor-to-sensor reproducibility, manufacturability, and low cost. A new approach to PoC detection of protein disease markers involves the use of virus particles, rather than antibodies, within a bioaffinity capture layer.  Relative to antibodies, virus particles have several advantages that make them attractive for emerging PoC sensor technologies:  First, virus particles can be engineered to bind virtually any protein – even toxic proteins for which antibody development is difficult.  Second, virus particles are less thermally and chemically labile than antibodies, dramatically simplifying the storage and transport of biosensors that rely on virus–based bioaffinity layers. Finally, virus particles that are capable of antibody-like affinities can be produced in quantity for far lower cost. In this talk I describe a PoC biosensor that exploits electrodeposited bioaffinity layers that consist of a composite of virus particles with an electrically conductive polymer, poly(3,4 ethylenedioxythiophene) or PEDOT. <br /><br /><strong>Seminarium</strong><strong> 2</strong><strong>:</strong><br />Motivated by potential benefits such as sensor user-friendly, multiplexing capabilities and high sensitivities, nanophotonic point-of-care biosensor platforms have profiled themselves as an excellent alternative to traditional analytical techniques. The main objective of our research is to achieve ultrasensitive platforms for label-free analysis using nanophotonic technologies and custom-designed biofunctionalization protocols, accomplishing the requirements of disposability and portability. We are using innovative designs of nanophotonic biosensors based on silicon photonics technology (bimodal waveguide nanointerferometers) or nanoplasmonics (gold nanostructures) and full microfluidics lab-on-chip integration. We employ dedicated biofunctionalization routes of the biological receptors (as proteins or genomic strands) ensuring selectivity, life-cycle, non-fouling properties and reusability. We have demonstrated the suitability of our photonic nanobiosensors for the detection, with extremely sensitivity and selectivity, of environmental pollutants and human disease biomarkers. In all cases, our sensing methodology has shown excellent robustness with high reproducibility and sensitivity, rendering in valuable tool for the fast diagnostics of un-treated bodily fluids or environmental samples.</div> Physics Colloquium: Compacted dimensions and singular plasmonic surfaces<p>PJ, lecture hall, Fysik Origo, Fysik</p><p>​Special Colloquium by Professor Sir John Pendry, Imperial College London, UK</p><h4 class="chalmersElement-H4">​Abstract:</h4> <div>In advanced field theories, there can be more than four dimensions to space, the excess dimensions described as compacted and unobservable on everyday length scales. We report a simple model, unconnected to field theory, for a compacted dimension realized in a metallic metasurface periodically structured in the form of a grating comprising a series of singularities. An extra dimension of the grating is hidden, and the surface plasmon excitations, though localized at the surface, are characterized by three wave vectors rather than the two of typical two-dimensional metal grating. We propose an experimental realization in a doped graphene layer.</div>,-Microtechnology-and-Nanoscience.aspx,-Microtechnology-and-Nanoscience.aspxEmanuel Haglund, Microtechnology and Nanoscience<p>Kollektorn, lecture room, MC2-huset, MC2</p><p>​Title: VCSEL Cavity Engineering for High-Speed Modulation and Silicon Photonics Integration</p>​<span><br />Emanuel <span class="text-normal page-content">is a PhD student at the </span>Photonics Laboratory<span style="display:inline-block"></span></span><br /><span><span class="text-normal page-content">Faculty opponent is: Professor Elyahou (Eli) Kapon, Laboratory of the Physics of Nanostructures EPFL, Lausanne Switzerland</span><br />Examiner and main supervisor: Professor Anders Larsson<br />Co-supervisor: Docent Johan Gustavsson<span style="display:inline-block"></span></span> about Teaching and Learning<p>PJ, lecture hall, Fysik Origo, Fysik</p><p>Organiser: Gothenburg Physics Centre</p><p><strong>Programme:</strong> Read more on the Swedish page.<br /></p> on cat states<p>Luftbryggan, MC2, Kemivägen 9</p><p>​This is the 3rd journal club meeting on cat states, profiting from the participation of Steven M. Girvin from Yale.</p><div><h5 class="chalmersElement-H5">Single Cavity</h5> <span style="font-weight:700"></span><table cellspacing="0" width="100%" class=" chalmersTable-default " style="font-size:1em"><tbody><tr class="chalmersTableEvenRow-default"><td class="chalmersTableEvenCol-default" rowspan="1" colspan="1" style="width:104px">​10:​30 - 11:10<br /><br /></td> <td class="chalmersTableOddCol-default" rowspan="1" colspan="1"><span style="font-weight:700">​​​Laure Bruhat</span>: Implementing a universal gate set on a logical qubit encoded in an oscillator<br /><br /></td></tr> <tr class="chalmersTableOddRow-default"><td class="chalmersTableEvenCol-default" rowspan="1" colspan="1" style="width:104px">​11:10 - 12:10 <br /><br /></td> <td class="chalmersTableOddCol-default">​<span style="font-weight:700">Steven M. Girvin</span>: Quantum Information Processing with Microwave Photons<br /><br /></td></tr> <tr class="chalmersTableEvenRow-default"><td class="chalmersTableEvenCol-default" rowspan="1" colspan="1" style="width:104px">​12:10 - 13:20<br /><br /></td> <td class="chalmersTableOddCol-default">​Lunch<br /><br /></td></tr> <tr class="chalmersTableOddRow-default"><td class="chalmersTableEvenCol-default" rowspan="1" colspan="1" style="width:104px">​</td> <td class="chalmersTableOddCol-default">​</td></tr></tbody></table> <h5 class="chalmersElement-H5">Several cavities​</h5></div> <div><table cellspacing="0" width="100%" class=" chalmersTable-default" style="font-size:1em"><tbody><tr class="chalmersTableEvenRow-default"><td class="chalmersTableEvenCol-default" rowspan="1" colspan="1">​13:20 - 14:10<br /><br /></td> <td class="chalmersTableOddCol-default" rowspan="1" colspan="1">​<span style="font-weight:700">Pontus Wikståhl</span>: Quantum annealing with all-to-all connected non-linear oscillators<br /><br /></td></tr> <tr class="chalmersTableOddRow-default"><td class="chalmersTableEvenCol-default" rowspan="1" colspan="1">​14:10 - 15:00<br /><br /></td> <td class="chalmersTableOddCol-default">​<span style="font-weight:700">Steven M. Girvin</span>: Yale efforts, focus on scalability<span style="background-color:transparent;font-size:1em">​</span><br /><br /></td></tr> <tr class="chalmersTableEvenRow-default"><td class="chalmersTableEvenCol-default" rowspan="1" colspan="1">15:00 - 15:20<br />​</td> <td class="chalmersTableOddCol-default">​coffee break<br /><br /></td></tr> <tr class="chalmersTableOddRow-default"><td class="chalmersTableEvenCol-default" rowspan="1" colspan="1">15:20 - 16:20<br />​</td> <td class="chalmersTableOddCol-default">​Round table discussion: perspectives on scalability<br /><br /></td></tr> <tr class="chalmersTableEvenRow-default"><td class="chalmersTableEvenCol-default" rowspan="1" colspan="1">​16:20 - 16:30<br /><br /></td> <td class="chalmersTableOddCol-default">​conclusions<br /><br /></td></tr></tbody></table></div> Information Processing with Microwave Photons<p>Luftbryggan, MC2, Kemivägen 9</p><p>​Talk by Steven M. Girvin, Yale Quantum Institute</p>​<div>Abstract:</div> <div>This talk will describe recent theoretical and experimental progress towards creation of a modular architecture for quantum information processing in which the qubits are not material objects but rather superposition states of microwave photons stored in cavities with millisecond lifetimes.  The Josephson junction elements used as qubits in more traditional architectures are used here only as ancillae to provide universal control over the non-classical photon states.   Recent experimental progress in execution of new gate operations that entangle photons in separate cavities will be described.  These gates [SWAP, C-SWAP (Fredkin), exponential-SWAP] have the remarkable feature that they are universal in the sense that they do not depend on the particular encoding used to store quantum information in the photons.  The modular approach based on photon states is also highly advantageous for quantum error correction and fault tolerance.<br /></div> by Axel Brandenburg<p>PJ, lecture hall, Fysik Origo, Fysik</p><p>​Seminar by Axel Brandenburg, Nordita Title: Magnetohydrodynamic field generation</p><h4 class="chalmersElement-H4">Abstract:</h4> <div>Magnetic fields are prominent players in virtually all areas of astrophysics, Theory and simulations demonstrate their exponential growth starting from weak seed magnetic fields that, in turn, are generated by some battery term. This is the self-excited dynamo, a tremendously important concept for the utilization of electricity since the works of Wheatstone, von Siemens, and Varley of 1866. Homogeneous self-excited dynamos, which do not have wires, are susceptible to short-circuiting themselves. Although anticipated already 99 years by Larmor, it was only since the 1970s that astrophysical dynamos became theoretical and numerical reality and not just ideas. Since 2000, experimental realizations have begun to expand our understanding into corners of parameter space not yet accessible to simulations.</div> <div> </div> <div>In my talk, I will highlight the concepts of small-scale and large-scale dynamos, the dependence on the ratio of viscous to resistive dissipation, the inverse turbulent cascade of magnetic helicity, and new classes of large-scale dynamos beyond just helical ones. In density-stratified systems, cross helicity, characterizing the linkage between magnetic and vortex tubes, plays a rote in producing spots, perhaps like those seen on the Sun. In spite of much progress, though, we are still not sure how exactly the solar dynamo works, whether primordial magnetic fields play a role in galactic magnetism, and whether such primordial fields are perhaps even fully helical.</div> coffee seminar with Jonathan Burnett<p>Kollektorn, lecture room, MC2-huset, MC2</p><p></p> Quantum Photonics: Exploiting quantum and photonic confinements at the nano-scale<p>h-bar, C511, MC2</p><p>​Talk by Professor Eli Kapon, EPFL in Lausanne, Switzerland</p><strong>​Abstract:</strong><div><div>Preparation and processing of single photons and other quantum states of light is a prerequisite for an important class of quantum science and technology platforms. Integration of sources of quantum light with various photonic elements would allow the realization of compact, inexpensive and efficient photonic chips for generating, processing and detecting single photons and their combinations. Such systems can be realized by integrating semiconductor quantum dots (QDs) with photonic crystal (PhC) cavities and waveguides. Moreover, many features of light-matter interaction can be tailored in such structures due to quantum and photonic confinements at the 10-100nm scale. We discuss in some detail the realization and investigation of such systems using organometallic vapor phase epitaxy of site-controlled QDs and their integration with “tailored-potential” PhC structures.</div> <div><br /></div> <div><strong>References:</strong></div> <div>A. Surrente et al., Nano Research 9, (11), 3279-3290 (2016).</div> <div>M. Calic et al., Scientific Reports 7, 4100 (2017).</div></div> <div><br /></div> <div><br /></div> Lim, Physics<p>Kollektorn, lecture room, MC2-huset, MC2</p><p>​ Title of thesis: Novel materials for high capacity sulphur based batteries.</p><h4 class="chalmersElement-H4">Abstract:</h4> <div>Batteries have become a vital part of our everyday lives and are used in a wide range of portable electronic devices (e.g. mobile phones, laptops, toy, and power tools). With the increased problems of environmental pollution, due to the use of fossil fuels for electric energy and transportation, there is an increased need for high capacity batteries for load levelling in renewable energy systems (wind, solar, tidal, etc.) and for electric vehicles. Li-ion batteries are currently very successful in portable applications. However, the specific capacity of current systems (&lt; 250 mAh/g, &lt; 120 Wh/kg), typically based on lithiated graphite anodes and metal oxide cathodes, is not sufficient for large-scale applications. In addition, there is also a need to improve battery technology in terms of price and sustainability concerning the raw of materials used. This has motivated research on next generation battery technology based on other chemistries.</div> <div> </div> <div>One of the most promising chemistries for next generation batteries is based on the conversion of sulphur. As an example, the theoretical discharge capacity of a lithium-sulphur cell is 1675 mAh/g or 2500 Wh/kg. Sulphur can also be coupled to sodium or used in the form a metal sulphide (e.g. FeS2), still with superior capacity compared to Li-ion technology. Considering that the active material, sulphur, has a low cost and is abundant brings also the potential for a low cost and sustainable technology. However, even though sulphur-based batteries are very promising their theoretical capacity has so far not been realised in practice in a cell with long cycle life and high charge/discharge efficiency.</div> <div> </div> <div>In this thesis, I present new materials concepts aiming to enable next generation high capacity batteries based on the conversion of sulphur. The main target has been to improve the capacity, but the materials used have also good perspective in terms of sustainability and price. A key to improve the properties has been to tailor materials on the nanoscale. One example is the fibre-based materials prepared by electrospinning. These include carbon structures for high capacity and high rate electrodes as well as gel-polymer electrolyte membranes. The results presented in the thesis show that high discharge capacity and good cycle performance can be achieved with the new materials concepts. The functional mechanisms behind the concepts is discussed and the role of different material aspects is revealed.</div> <div> </div> <div> KEYWORDS: next generation batteries, lithium-sulphur battery, catholyte, gel electrolyte, electrospinning</div>,-Microtechnology-and-Nanoscience.aspx,-Microtechnology-and-Nanoscience.aspxAhmed Hassona, Microtechnology and Nanoscience<p>Kollektorn, lecture room, MC2-huset, MC2</p><p>​​Title: Non-galvanic Interconnects for Millimeter-wave Systems</p>​<br /><span class="text-normal page-content">​<span><span>Ahmed is a PhD student at the Microwave Electronics Laboratory <br /><span class="text-normal page-content"><span>​</span><span class="text-normal page-content">Discussion leader: Dr. Jan Svedin, Deputy Director of Research at the Swedish Defence Research Agency (FOI)<br />Examiner: Professor Herbert Zirath<br />Main supervisor:</span></span></span> Associate Professor Vessen Vassilev</span></span> thesis presentation: Johan Frisch<p>Raven and the Fox, multifunctional room, Forskarhuset Fysik, MC2</p><p>​Title: Information processing in the brain</p><h4 class="chalmersElement-H4">Abstract:</h4> <div>The understanding of the information processing in the brain have eluded many attempt. A partial explanation can be reached with organising neurons in groups, placing state memories in the dendrites and having a separate information processing system in the soma.</div> Physics Colloquium: Validity and failure of the Boltzmann weight<p>Kollektorn, lecture room, MC2-huset, MC2</p><p>Colloquium by Constantino Tsallis, Brazilian Center for Research in Physics, Brazil</p><h4 class="chalmersElement-H4">Abstract:</h4> <div>An analysis will be presented of the foundations of statistical mechanics, both classical and quantum. We will focus on a few selected complex systems for which the Boltzmann-Gibbs entropy and statistical mechanical traditional concepts differ from those that satisfactorily apply to analytical, experimental and computational evidences. In particular, first-principle dynamical simulations of models with long-range interactions neatly exhibit when the celebrated Boltzmann weight is valid and when it fails. <a href="">A Bibliography can be found here. </a></div> by Honorary Doctors 2018<p>Palmstedtsalen, university building, Palmstedtsalen, Campus Johanneberg</p><p>​ Welcome to lectures given by the honorary doctors 2018 ​Ruth Graham, independent consultant in engineering education and entreprenurship &quot;The global state of the art in engineering education&quot; Marcus Wallenberg, industrial leader and entrepreneur &quot;Investments in research and innovation key factors for further development&quot; Lars G Larsson, nuclear safety expert in Sweden and abroad &quot;Strategic Nuclear Safety memories from East and West&quot; Anne Nouri, professor of mathematics at the University of Aix- Marseille, France &quot;On anyons from a mathematical point of view&quot; Read more about the honorary doctors here ​For attendance please register here After the lectures you are invited to a &quot;fika&quot; and a chat with the honorary doctors.</p> thesis presentation: Johanna Nilsson<p>Raven and Fox, 5th Floor, Fysik Forskarhuset</p><p>Title: In vitro study of the effects of cortisol on mesenchymal stem cells and disc cells from patients with disc degeneration, as well as investigation of its potential quantification. Thesis work performed at the Lundberg Lab for Orthopedic Research, Gothenburg University</p><h4 class="chalmersElement-H4">Abstract:</h4> <div>Low back pain (LBP) is one of the biggest health issues in the western world today</div> <div>and its main cause is intervertebral disc degeneration. Chronic pain (LBP) induced</div> <div>stress correlates with high cortisol levels and have been linked with a number of</div> <div>adverse effects on the body and its cells. This master thesis investigates the effect</div> <div>that high cortisol levels have on disc cells (DC) and mesenchymal stem cells (MSC)</div> <div>from patients with intervertebral disc degeneration. The aim was to study the effect</div> <div>of cortisol in terms of chondrogenesis, proteoglycan production, and apoptosis. Cell</div> <div>viability, proliferation, and morphology of the cells were also investigated. The two</div> <div>cell types were studied both in monolayer and in pellet cultures, in the presence</div> <div>of cortisol at two concentrations, 150 and 300 ng/mL. The results showed that</div> <div>the cortisol did have a negative effect on the proliferation of the disc cells. For</div> <div>both cell types for the cortisol treated pellets, less proteoglycan production were</div> <div>seen and a higher degree of apoptotic cells were found compared to the control.</div> <div>Lastly, differentiation was compromised in MSCs treated with cortisol. However,</div> <div>chondrogenesis was achieved in all pellet systems. No clear difference were seen</div> <div>for the morphology and viability of the cells. To conclude, cortisol do seem to</div> <div>have an negative impact on mesenchymal stem cells and disc cells from patients</div> <div>with disc degeneration at the concentrations tested in this thesis. This thesis also</div> <div>explore different methods for measuring long-term cortisol level in human hair with</div> <div>the prospective of use in patients with low back pain. Two methods were chosen</div> <div>and evaluated, HPLC-MS2 and ELISA, both with high prospects. However, more</div> <div>research is needed to decide which method is the most suitable.</div> <div> </div> Physics Colloquium: Lene Vestergaard Hau<p>Lecture hall FB, Origo building, Fysikgården 4, campus Johanneberg</p><p>Title of talk: The art of taming light: What we can learn from a bacterium… and beyond. Special Physics Colloquium by Professor Lene Vestergaard Hau, Harvard University, USA</p> thesis presentation: Martin Ekman<p>Nexus, Origo, Fysik</p><p>​Title: Design of a Metasurface Based Optomechanical Resonator</p><p></p> <h4 class="chalmersElement-H4">Abstract: </h4> <div>The sub-field of physics called optomechanics has been of interest in recent decades as a possible alternative to observe quantum effects at room temperature. In this thesis the optical properties of a thin GaAs membrane with an array of holes are investigated through simulations using COMSOL Multiphysics, a software which is based on the finite element method. The aim was specifically to focus on looking for membranes of high reflectance and low thickness, and eventually found structures at three different thicknesses 50, 100 and 150 nm with reflectance values of 99.9 % and higher. Such membranes would allow for laser cooling to observe quantum phenomena instead of cryogenic liquids. This thesis also briefly investigates different structures, and multi-element optomechanics in the form of double membranes. The latter as a step towards allowing for studying single-photon strong coupling in cavity optomechanics. </div> <p></p>,-Microtechnology-and-Nanoscience.aspx,-Microtechnology-and-Nanoscience.aspxSebastian Gustafsson, Microtechnology and Nanoscience<p>Kollektorn, lecture room, MC2-huset, MC2</p><p>​Title: Nonlinear Measurement Techniques for Wideband Characterization of Microwave Devices</p><span><span><span class="text-normal page-content"><span style="display:inline-block">​Sebastian is a PhD student at the Microwave Electronics Laboratory<br />Faculty opponent is: Prof. Paul Tasker, School of Engineering, Cardiff University, UK<br />Examiner and main supervisor: Professor Herbert Zirath <br /><span></span>Co-supervisor: Assistant Professor Mattias Thorsell <br /></span></span></span></span> Lindroth, Physics<p>PJ, lecture hall, Fysik Origo, Fysik</p><p>Title of thesis: Thermal transport in van der Waals Solids and Inorganic Clathrates from first-principles calculations.</p><strong>Abstract: </strong><br />To be announced.<br /> Peerboom, Physics<p>Kollektorn, lecture room, MC2-huset, MC2</p><p>Title of thesis: Unraveling the molecular mechanisms of herpes simplex virus attachment and release using cell membrane mimics.</p><h4 class="chalmersElement-H4">Abstract:</h4> <div>The herpes simplex virus is a widespread human pathogen, most commonly known for causing cold sores. Its infection cycle is initiated with the formation of multiple bonds between viral glycoproteins and cellular glycosaminoglycans, which are long polysaccharide chains found close to the cell surface. While the key molecular actors of this initial attachment have been identified, less is known about the dynamics of the herpes-glycosaminoglycan interaction.</div> <div> </div> <div>This thesis focuses on implementing bioanalytical assays to address two main research questions. First, we investigated how specific physicochemical properties of the glycosaminoglycan chains and of the viral glycoproteins influence the binding characteristics of the virus, in particular particle mobility and binding kinetics. Second, we aimed at elucidating how new progeny virus successfully releases from the cell membrane without getting trapped. To this end, we used two different cell membrane mimics. The first one consisted of end-grafted glycosaminoglycan chains, mimicking the native brush-like architecture of glycosaminoglycans, while the second one was obtained through incorporation of native membrane material into supported lipid bilayers. To study virus mobility and measure affinities and binding forces, we mainly used total internal reflection fluorescence microscopy in combination with single particle tracking, and atomic force microscopy.</div> <div> </div> <div>Our results showed that the type of GAG or the glycosylation of the viral glycoproteins influence the diffusive behavior of herpes simplex virions, which we attributed to a change in binding forces of the herpes-glycosaminoglycan interaction. Furthermore, we suggest that a highly glycosylated region, called mucin-like region, found on certain glycoproteins balances the herpes-glycosaminoglycan interaction to ensure successful release.</div> <div> </div> <div>Taken together, this thesis provides new insights into the mechanisms regulating attachment and release of the herpes simplex virus to and from the cell membrane, which could be of relevance to the development of new strategies in antiviral research.</div> On dark matter<p>Kollektorn, lecture room, MC2-huset, MC2</p><p>This workshop will bring together theoretical and experimental physicists to identify optimal strategies for the analysis of next generation dark matter search experiments.</p><h4 class="chalmersElement-H4">Abstract:</h4> <div> Increasingly accurate astronomical and cosmological observations reveal that most of the matter in the Universe is non luminous, and made of an unknown substance called dark matter (DM). The nature of DM remains a mystery, but indirect evidence points towards a new hypothetical particle as the prime candidate. Although the DM particle has so far escaped detection, a new generation of experiments is or will soon start operating, reaching the sensitivity required by the state-of-the-art theories to discover the first non-gravitational signals of DM.</div> <div><span class="text-normal page-content"><div> </div> <div>The aim of this conference is to deliver optimised strategies for DM particle identification. This aim will be pursued by bringing together theoretical and experimental physicists in order to direct efforts jointly and wisely.</div> <div> </div> <div> </div> <div> </div> <div><strong>Topics to be covered in the conference include:</strong></div> <div> </div> <div>Status report on the experimental search for DM.</div> <div> </div> <div>DM phenomenology.</div> <div> </div> <div>DM theory.</div> <div> </div> <div>Complementarity of different DM detection strategies and global statistical analyses.</div> <div> </div> <div>Astrophysical and nuclear physics inputs.</div></span></div> fuelled reactors<p>PJ lecture hall, Fysikgården 1, Chalmers</p><p></p>​<span style="font-family:helvetica,arial,sans-serif">Professor Janne Wallenius from KTH, recently known for his project concerning small lead-cooled reactors for use in remote areas, will visit Chalmers to give a lecture on his new research on neptunium fuelled reactors and their remarkable properties.</span> coffee seminar Edoardo Trabaldo<p>Fasrummet, meeting room, MC2-huset, MC2</p><p></p>,-Microtechnology-and-Nanoscience.aspx,-Microtechnology-and-Nanoscience.aspxHans He, Microtechnology and Nanoscience<p>Fasrummet A820, MC2</p><p>​Title: Engineering Epitaxial Graphene for Quantum Metrology ​</p>​Hans He is a PhD student at the <span><span><span>Quantum Technology Laboratory<span style="display:inline-block"><br /></span></span></span></span><br /><span><span><span><span class="text-normal page-content"><span>​</span><span></span><span class="text-normal page-content"></span></span></span></span></span><span><span><span><span class="text-normal page-content"><span class="text-normal page-content">Discussion leader: Professor Avgust Yurgens<br />Examiner: Professor Sergey Kubatkin<br />Main supervisor:</span></span></span> Assistant Professor<span></span> Samuel Lara Avila<br /><span><span class="text-normal page-content"><span class="text-normal page-content"><span style="display:inline-block"><span style="display:inline-block"><span style="display:inline-block"></span></span></span></span></span></span></span></span><br /> colloquium: Using superconducting qubits for analog quantum simulation<p>Kollektorn, lecture room, MC2-huset, MC2</p><p>Talk by Gerhard Kirchmair, IQOQI Innsbruck, Austria</p>​<br /><img src="/SiteCollectionImages/Institutioner/MC2/Blandat/Kirchmair.jpg" class="chalmersPosition-FloatLeft" alt="" style="margin:5px;width:150px;height:200px" /><br />Univ. -Prof. Dr. Gerhard Kirchmair, Junior Research Director at the Institut für Quantenoptik und Quanteninformation, Innsbruck.<br />öm.aspx coffee seminar with Maria Ekström<p>Luftbryggan, conference room, MC2-huset, MC2</p><p></p> Study 2018<p>Hindås, Sweden</p><p>2D materials for environment and energy applications</p><h5 class="chalmersElement-H5">Description of the event:</h5> <div>The Graphene Study 2018, summer edition, titled 2D materials for environment and energy applications, will delve into deeper aspects of how things work, exploring experimenters' techniques in studying energy and environmental applications for graphene, mainly filtration and energy storage technologies. Leading academic and industry experts from around the world, including Prof. Rohit Karnik from the Massachusetts Institute of Technology, Prof. Aleksandra Radenovic from the École Polytechnique Fédérale de Lausanne and Dr. A. Pacheco from Tecnalia will provide delegates with their insights on topics from nanofluidics and power generation to desalination using graphene.</div>