| 1. |
- Abelev, Betty, et al.
(författare)
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Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :11
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Tidskriftsartikel (refereegranskat)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
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| 2. |
- Crous, Pedro W., et al.
(författare)
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Fungal Planet description sheets: 1383–1435
- 2022
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Ingår i: Persoonia: Molecular Phylogeny and Evolution of Fungi. - : Naturalis Biodiversity Center. - 0031-5850 .- 1878-9080. ; 48, s. 261-371
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Tidskriftsartikel (refereegranskat)abstract
- Novel species of fungi described in this study include those from various countries as follows: Australia, Agaricus albofoetidus, Agaricus aureoelephanti and Agaricus parviumbrus on soil, Fusarium ramsdenii from stem cankers of Araucaria cunninghamii, Keissleriella sporoboli from stem of Sporobolus natalensis, Leptosphaerulina queenslandica and Pestalotiopsis chiaroscuro from leaves of Sporobolus natalensis, Serendipita petricolae as endophyte from roots of Eriochilus petricola, Stagonospora tauntonensis from stem of Sporobolus natalensis, Teratosphaeria carnegiei from leaves of Eucalyptus grandis × E. camaldulensis and Wongia ficherai from roots of Eragrostis curvula. Canada, Lulworthia fundyensis from intertidal wood and Newbrunswickomyces abietophilus (incl. Newbrunswickomyces gen. nov.) on buds of Abies balsamea. Czech Republic, Geosmithia funiculosa from a bark beetle gallery on Ulmus minor and Neoherpotrichiella juglandicola (incl. Neoherpotrichiella gen. nov.) from wood of Juglans regia. France, Aspergillus rouenensis and Neoacrodontium gallica (incl. Neoacrodontium gen. nov.) from bore dust of Xestobium rufovillosum feeding on Quercus wood, Endoradiciella communis (incl. Endoradiciella gen. nov.) endophytic in roots of Microthlaspi perfoliatum and Entoloma simulans on soil. India, Amanita konajensis on soil and Keithomyces indicus from soil. Israel, Microascus rothbergiorum from Stylophora pistillata. Italy, Calonarius ligusticus on soil. Netherlands, Appendopyricularia juncicola (incl. Appendopyricularia gen. nov.), Eriospora juncicola and Tetraploa juncicola on dead culms of Juncus effusus, Gonatophragmium physciae on Physcia caesia and Paracosmospora physciae (incl. Paracosmospora gen. nov.) on Physcia tenella, Myrmecridium phragmitigenum on dead culm of Phragmites australis, Neochalara lolae on stems of Pteridium aquilinum, Niesslia nieuwwulvenica on dead culm of undetermined Poaceae, Nothodevriesia narthecii (incl. Nothodevriesia gen. nov.) on dead leaves of Narthecium ossifragum and Parastenospora pini (incl. Parastenospora gen. nov.) on dead twigs of Pinus sylvestris. Norway, Verticillium bjoernoeyanum from sand grains attached to a piece of driftwood on a sandy beach. Portugal, Collybiopsis cimrmanii on the base of living Quercus ilex and amongst dead leaves of Laurus and herbs. South Africa, Paraproliferophorum hyphaenes (incl. Paraproliferophorum gen. nov.) on living leaves of Hyphaene sp. and Saccothecium widdringtoniae on twigs of Widdringtonia wallichii. Spain, Cortinarius dryosalor on soil, Cyphellophora endoradicis endophytic in roots of Microthlaspi perfoliatum, Geoglossum laurisilvae on soil, Leptographium gemmatum from fluvial sediments, Physalacria auricularioides from a dead twig of Castanea sativa, Terfezia bertae and Tuber davidlopezii in soil. Sweden, Alpova larskersii, Inocybe alpestris and Inocybe boreogodeyi on soil. Thailand, Russula banwatchanensis, Russula purpureoviridis and Russula lilacina on soil. Ukraine, Nectriella adonidis on overwintered stems of Adonis vernalis. USA, Microcyclus jacquiniae from living leaves of Jacquinia keyensis and Penicillium neoherquei from a minute mushroom sporocarp. Morphological and culture characteristics are supported by DNA barcodes.
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| 3. |
- Ivanisevic, Nikola, 1988-
(författare)
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Circuit Design Techniques for Implantable Closed-Loop Neural Interfaces
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Implantable neural interfaces are microelectronic systems, which have the potential to enable a wide range of applications, such as diagnosis and treatment of neurological disorders. These applications depend on neural interfaces to accurately record electrical activity from the surface of the brain, referred to as electrocorticography (ECoG), and provide controlled electrical stimulation as feedback. Since the electrical activity in the brain is caused by ionic currents in neurons, the bridge between living tissue and inorganic electronics is achieved via microelectrode arrays. The conversion of the ionic charge into freely moving electrons creates a built-in electrode potential that is several orders of magnitude larger than the ECoG signal, which increases the dynamic range, resolution, and power consumption requirements of neural interfaces. Also, the small surface area of microelectrodes implies a high-impedance contact, which can attenuate the ECoG signal. Moreover, the applied electrical stimulation can also interfere with the recording and ultimately cause irreversible damages to the electrodes or change their impedance. This thesis is devoted to resolving the challenges of high-resolution recording and monitoring the electrode impedance in implantable neural interfaces.The first part of this thesis investigates the state-of-the-art neural interfaces for ECoG and identifies their limitations. As a result of the investigation, a high-resolution ADC is proposed and implemented based on a ΔΣ modulator. In order to enhance performance, dynamic biasing and area-efficient switched-capacitor circuits were proposed. The ΔΣ modulator is combined with the analog front-end to provide a complete readout solution for high-resolution ECoG recording. The corresponding chip prototype was fabricated in a 180 nm CMOS process, and the measurement results showed a 14-ENOB over a 300-Hz bandwidth while dissipating 54-μW.The second part of this thesis expands upon the well-known methods for impedance measurements and proposes an alternative digital method for monitoring the electrode-tissue interface impedance. The proposed method is based on the system identification technique from adaptive digital filtering, and it is compatible with existing circuitry for neural stimulation. The method is simple to implement and performs wide-band measurements. The system identification was first verified through behavioral simulations and then tested with a board-level prototype in order to validate the functionality under real conditions. The measurement results showed successful identification of the electrode-electrolyte and electrode-skin impedance magnitudes.
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| 4. |
- Abelev, Betty, et al.
(författare)
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Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :7
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
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| 5. |
- Albertsson, Dagur Ingi, 1993-, et al.
(författare)
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Compact Macrospin-Based Model of Three-Terminal Spin-Hall Nano Oscillators
- 2019
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Ingår i: IEEE transactions on magnetics. - : IEEE Press. - 0018-9464 .- 1941-0069. ; 55:10
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Tidskriftsartikel (refereegranskat)abstract
- Emerging spin-torque nano oscillators (STNOs) and spin-Hall nano oscillators (SHNOs) are potential candidates for microwave applications. Recent advances in three-terminal magnetic tunnel junction (MTJ)-based SHNOs opened the possibility to develop more reliable and well-controlled oscillators, thanks to individual spin Hall-driven precession excitation and read-out paths. To develop hybrid systems by integrating three-terminal SHNOs and CMOS circuits, an electrical model able to capture the analog characteristics of three-terminal SHNOs is needed. This model needs to be compatible with current electric design automation (EDA) tools. This work presents a comprehensive macrospin-based model of three-terminal SHNOs able to describe the dc operating point, frequency modulation, phase noise, and output power. Moreover, the effect of voltage-controlled magnetic anisotropy (VCMA) is included. The model shows good agreement with experimental measurements and could be used in developing hybrid three-terminal SHNO/CMOS systems.
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| 6. |
- Albertsson, Dagur Ingi
(författare)
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Spintronic and Electronic Oscillators for Magnetic Field Sensing and Ising Machines
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Oscillators can exhibit a range of complex dynamics which are often encountered in nature. These characteristics include synchronization, injection locking, chaos, bifurcations, etc. To date, the applications of electronic oscillators has mostly been limited to communication systems. However, in recent years, the possibility of using the rich dynamics of oscillators in unconventional applications, including time-based information processing and computational applications, has been also explored. In this thesis, this potential is investigated using emerging spintronic oscillators and established electronic oscillators. The first part of this thesis targets emerging spintronic oscillators, which exhibit a range of attractive features, including GHz operating frequency, wide tunability and nanoscale size. To explore the potential of these devices, an electrical behavioural model was developed for the promising three-terminal spin-Hall nano-oscillator. The behavioural model is based on the macrospin approximation, which is commonly used to describe the operation principles of spintronic oscillators, and it was implemented in Verilog-A. Moreover, the behavioural model was verified against experimental measurements from literature, demonstrating that the most important characteristics of three-terminal spin-Hall nano-oscillators are accurately captured. Subsequently, two potential applications that could benefit from the unique characteristics of spintronic oscillators were identified and explored. First, a magnetic field sensing system, which takes advantage of the wide frequency tunability of spintronic oscillators as a function of externally applied magnetic field, was proposed and demonstrated. This sensing system, inspired by voltage-controlled oscillator analog-to-digital converters, shows performance similar to the state-of-the-art magnetic field sensors, making it a promising application for spintronic oscillators. Next, the possibility of utilizing spintronic oscillators to realize Ising machines (IMs) was explored and demonstrated with numerical simulations. This was the first-time demonstration of spintronic oscillator-based Ising machines. The numerical simulation results show that spintronic oscillators are a promising device to realize ultra-fast Ising Machines able to solve complex combinatorial optimization problems on nano-second time scale.The second part of the thesis extends on the idea of oscillator-based IMs, but using electronic oscillators. The potential of realizing highly reconfigurable oscillator-based IMs based on quasiperiodically modulated coupling was explored. The advantages and potential challenges associated with this approach were highlighted, and a proof-of-concept IM using CMOS ring oscillators was proposed and simulated. Finally, a completely new type of IMs based on bifurcations in a network of coupled Duffing oscillators was proposed and developed. This work highlights a new research direction based on using dynamical systems implemented with analog circuits to realize IMs.
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| 7. |
- Atallah, Jad. G., et al.
(författare)
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A direct conversion WiMAX RF receiver front-end in CMOS technology
- 2007
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Ingår i: ISSCS 2007. - NEW YORK : IEEE. - 9781424409686 ; , s. 37-40
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Konferensbidrag (refereegranskat)abstract
- This paper presents a direct conversion RF receiver front-end supporting the WiMAX standard. The front-end is implemented in 0.18um CMOS technology and designed using the ARCHER software. It shows how the design flow can be accelerated starting from the standard specifications and going down to schematics. All this is accompanied by test benches to extract the relevant metrics. This front-end provides a total gain of 31dB, a noise figure of 3.3dB, an IIP2 of 49.5dBm, and an IIP3 of -13.8dBm.
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| 8. |
- Chaourani, Panagiotis, 1989-, et al.
(författare)
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A Study on Monolithic 3-D RF/AMS ICs: Placing Digital Blocks Under Inductors
- 2018
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Ingår i: IEEE SOI-3D-Subthreshold Microelectronics Technology Unified Conference (S3S). - : IEEE conference proceedings.
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Konferensbidrag (refereegranskat)abstract
- The placement of bottom tier blocks under top-tierinductors could significantly improve the area-efficiency of M3DRF/AMS circuits, paving the way for new applications of thisintegration technology. This work investigates the potential ofplacing digital blocks in the bottom tier, underneath top tierinductors. A design-technology co-optimization flow is appliedand a number of design guidelines are suggested. These guidelinesensure high electromagnetic isolation between the two tiers, withminimum penalties on the loading of bottom tier wires, as wellas on the inductor’s performance.
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| 9. |
- Chaourani, Panagiotis, 1989-, et al.
(författare)
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Enabling Area Efficient RF ICs through Monolithic 3D Integration
- 2017
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Ingår i: Proceedings of the 2017 Design, Automation and Test in Europe, DATE 2017. - : Institute of Electrical and Electronics Engineers (IEEE). - 9783981537093 ; , s. 610-613
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Konferensbidrag (refereegranskat)abstract
- The Monolithic 3D (M3D) integration technology has emerged as a promising alternative to dimensional scaling thanks to the unprecedented integration density capabilities and the low interconnect parasitics that it offers. In order to support technological investigations and enable future M3D circuits, M3D design methodologies, flows and tools are essential. Prospective M3D digital applications have attracted a lot of scientific interest. This paper identifies the potential of M3D RF/analog circuits and presents the first attempt to demonstrate such circuits. Towards this, a M3D custom design platform, which is fully compatible with commercial design tools, is proposed and validated. The design platform includes process characteristics, device models, LVS and DRC rules and a parasitic extraction flow. The envisioned M3D structure is built on a commercial CMOS process that serves as the bottom tier, whereas a SOI process is used as top tier. To validate the proposed design flow and to investigate the potential of M3D RF/analog circuits, a RF front-end design for Zig-Bee WPAN applications is used as case-study. The M3D RF front-end circuit achieves 35.5 % area reduction, while showing similar performance with the original 2D circuit.
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| 10. |
- Chaourani, Panagiotis, et al.
(författare)
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Inductors in a Monolithic 3-D Process : Performance Analysis and Design Guidelines
- 2019
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Ingår i: IEEE Transactions on Very Large Scale Integration (vlsi) Systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 1063-8210 .- 1557-9999. ; 27:2, s. 468-480
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Tidskriftsartikel (refereegranskat)abstract
- Monolithic 3-D (M3D) integration technology has demonstrated significant area reduction in digital systems. Recently, its applications to other fields have been considered as well. To fully investigate the potential of M3D for radio-frequency/analog-mixed signal (RF/AMS) circuits and systems, the behavior of inductors in this technology needs to be evaluated. Toward this, in this paper, the effect of M3D integration on their inductance densities and quality factors has been analyzed. The impact of shields on M3D inductors has been investigated, as well as the shunting of multiple metal layers to form multimetal inductors. In an attempt to improve the area efficiency of M3D RF/AMS circuits, the potential of placing bottom-tier blocks underneath top-tier inductors has been identified, and a set of guidelines has been proposed to maximize the inter-tier electromagnetic isolation. These guidelines deal with the suitable position of both low- and high-frequency blocks, their wiring, as well as the type of shield that is needed between them and the inductors. To prove the efficiency of these guidelines, an array of bottom-tier resistors has been placed underneath a top-tier inductor, resulting in more than 50 dB of inter-tier isolation for frequencies up to 20 GHz.
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