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Dissertations / Theses on the topic 'NEXP] Physics'

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Published: 4 June 2021
Last updated: 4 May 2024

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1

Keshet, Aviv. "A next-generation apparatus for lithium optical lattice experiments." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/79254.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, February 2013.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 167-173).<br>Quantum simulation is emerging as an ambitious and active subfield of atomic physics. This thesis describes progress towards the goal of simulating condensed matter systems, in particular the physics of the Fermi-Hubbard model, using ultracold Lithium atoms in an optical lattice. A major goal of the quantum simulation program is to observe phase transitions of the Hubbard model, into Néel antiferromagnetic phases and d-wave superfluid phases. Phase transitions are generally accompanied by a change in an underlying correlation in a physical system. Such correlations may be most amenable to probing by looking at fluctuations in the system. Experimental techniques for probing density and magnetization fluctuations in a variety of atomic Fermi systems are developed. The suppression of density fluctuations (or atom "shot noise") in an ideal degenerate Fermi gas is observed by absorption imaging of time-of-flight expanded clouds. Intrap measurements of density and magnetization fluctuations are not easy to probe with absorption imaging, due to their extremely high attenuation. A method to probe these fluctuations based on speckle patterns, caused by fluctuations in the index of refraction for a detuned illumination beam, is developed and applied first to weakly interacting and then to strongly interacting in-trap gases. Fluctuation probes such as these will be a crucial tool in future quantum simulation of condensed matter systems. The quantum simulation experiments that we want to perform require a complex sequence of precisely timed computer controlled events. A distributed GUI-based control system designed with such experiments in mind, The Cicero Word Generator, is described. The system makes use of a client-server separation between a user interface for sequence design and a set of output hardware servers. Output hardware servers are designed to use standard National Instruments output cards, but the client-server nature allows this to be extended to other output hardware. Output sequences running on multiple servers and output cards can be synchronized using a shared clock. By using an FPGA-generated variable frequency clock, redundant buffers can be dramatically shortened, and a time resolution of 100ns achieved over effectively arbitrary sequence lengths. Experimental set-ups for producing, manipulating, and probing ultracold atomic gases can be quite complicated. To move forward with a quantum simulation program, it is necessary to have an apparatus that operates with a reliability that is not easily achieved in the face of this complexity. The design of a new apparatus is discussed. This Sodium-Lithium ultracold gas production machine has been engineered to incorporate as much experimental experience as possible to enhance its reliability. Particular attention has been paid to maximizing optical access and the utilization of this optical access, controlling the ambient temperature of the experiment, achieving a high vacuum, and simplifying subsystems where possible. The apparatus is now on the verge of producing degenerate gases, and should serve as a stable platform on which to perform future lattice quantum simulation experiments.<br>by Aviv Keshet.<br>Ph.D.
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2

Hammett, Jason. "Leptoquark production at next-to-leading order." Thesis, University of Southampton, 2014. https://eprints.soton.ac.uk/375122/.

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In this thesis we study the effective leptoquark model of Buchm�uller, R�uckl and Wyler, focusing on a particular type of scalar (R2) and vector (U1) leptoquark. The primary aim is to perform the calculations for leptoquark production at next-to-leading order (NLO) to establish the importance of the NLO contributions and in addition to this to determine how effective the narrow-width-approximation (NWA) is at NLO. For both the scalar and vector leptoquarks it is found that the NLO contributions are large, with the largest corrections occurring to the vector leptoquark calculations. For the scalar leptoquark it is found that the NWA provides a good approximation for determining the resonant peak, however the NWA is not as effective for the vector leptoquark - where large differences are observed at NLO. For both the scalar and vector leptoquarks it is found that there are large contributions away from the resonant peak, which are missing from the NWA results, and these make a significant difference to the total cross-section.
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De, Motte Darren C. E. "Cryogenic ion trapping for next generation quantum technologies." Thesis, University of Sussex, 2016. http://sro.sussex.ac.uk/id/eprint/66011/.

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Quantum technology has made great strides in the last two decades with trapped ions demonstrating all the necessary building blocks for a quantum computer. While these proof of principle experiments have been demonstrated, it still remains a challenging task to scale these experiments down to smaller systems. In this thesis I describe the development of technology towards scalable cryogenic ion trapping and quantum hybrid systems. I first discuss the fundamentals of ion trapping along with the demonstration of ion trapping on a novel surface electrode ion trap with a ring shaped architecture. I then present the development of a cryogenic vacuum system for ion trapping at ~4 K, which utilizes a closed cycle Gifford McMahon cryocooler with a helium gas buffered ultra-low vibration interface to mechanically decouple a ultra-high vacuum system. Ancillary technologies are also presented, including a novel in-vacuum superconducting rf resonator, low power dissipation ceramic based atomic source oven and an adaptable in-vacuum permanent magnet system for long-wavelength based quantum logic. The design and fabrication of microfabricated surface ion traps toward quantum hybrid technologies are then presented. A superconducting ion trap with an integrated high quality factor microwave cavity and vertical ion shuttling capabilities is described. The experimental demonstration of the cavity is also presented with quality factors of Q6~6000 and Q~15000 for superconducting niobium nitride and gold based cavities respectively, which are the highest demonstrated for microwave cavities integrated within ion trapping electrode architectures. An ion trap with a multipole electrode geometry is then presented, which is capable of trapping a large number of ions simultaneously. The homogeneity of five individual linear trapping regions are optimized and the design for the principle axis rotation of each linear region is presented. An overview of microfabrication techniques used for fabricating surface electrode ion traps is then presented. This includes the detailed microfabrication procedure for ion traps designed within this thesis. A scheme for the integration of ion trapping and superconducting qubit systems as a step towards the realization of a quantum hybrid system is then presented. This scheme addresses two key diffculties in realizing such a system; a combined microfabricated ion trap and superconducting qubit architecture, and the experimental infrastructure to facilitate both technologies. Solutions that can be immediately implemented using current technology are presented. Finally, as a step towards scalability and hybrid quantum systems, the interaction between a single ion and a microwaves field produced from an on chip microwave cavity is explored. The interaction is described for the high-Q microwave cavity designed in this thesis and a 171Yb+ion. A description of the observable transmission from the cavity is described and it is shown that the presence of a single ion can indeed be observed in the emission spectrum of high-Q microwave cavity even in the weak coupling regime.
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4

Kartakis, Sokratis. "Next generation cyber-physical water distribution systems." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/52704.

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Over the last decade, there has been a trend where water utility companies aim to make water distribution networks more intelligent in order to improve their quality of service, reduce water and energy waste, minimize maintenance costs etc., by incorporating Information and Communications Technologies (ICT). Current state of the art solutions use expensive power hungry deployments to monitor and transmit water network states periodically in order to detect anomalous behaviors, such as water leakage and bursts, and control water network assets. However, more than 97% of water network assets are found in remote areas, away from power and are often in geographically remote underpopulated areas; facts that make current approaches unsuitable for next generation more dynamic adaptive water networks. Battery-driven wireless sensor/actuator-based solutions are theoretically the perfect choice to support next generation cyber-physical water distribution systems. In this context, this thesis answers the question: "How can the communication be optimized to achieve sustainable Cyber-Physical Systems (CPS) deployed in such harsh environments exploiting limited resources by combining Information, Control, and Communication theory (I2C)? " In order to efficiently utilize underground wireless sensor and actuator network infrastructures, the concepts of edge data processing, anomaly detection and localization, based on compression, stream analyses and graph theory, are introduced. Furthermore, energy optimization and network sustainability by exploiting data-rate and communication scheduling adaptation, based on Lyapunov optimization, is proposed; while the benefits of aperiodic communication are investigated by accommodating event-triggered control technique into smart water networks. In addition to simulations based on real data, WaterBox and BentoBox evaluation platforms were developed to evaluate the proposed algorithms and prove the benefits of event-triggered control and Low Power Wide Area (LPWA) communication technologies against the state-of-the-art solutions. Through theoretical analysis, simulations, and real testbed experiments, the proposed algorithms and systems are shown to outperform contemporary solutions by achieving communication and actuation optimization, data reliability enhancement, while ensuring the sustainable operation of smart water networks. The work presented in this thesis should be of interest to researchers in the emerging areas Cyber-Physical Systems (CPS), Internet of Things (IoT), and Information and Communications Technology (ICT) for smart sustainable cites.
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5

Romeo, Lorenzo. "Semiconductor nanowires: the building block for next generation electronics and photonics." Doctoral thesis, Scuola Normale Superiore, 2016. http://hdl.handle.net/11384/86200.

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6

Melville, Stacey Elizabeth. "Next-to-soft radiative corrections in QCD and quantum gravity." Thesis, University of Glasgow, 2016. http://theses.gla.ac.uk/7774/.

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The origin of divergent logarithmic contributions to gauge theory cross sections arising from soft and collinear radiation is explored and a general prescription for tackling next-to-soft logarithms is presented. The NNLO Abelian-like contributions to the Drell-Yan K-factor are reproduced using this generalised prescription. The soft limit of gravity is explored where the interplay between the eikonal phase and Reggeization of the graviton is explained using Wilson line techniques. The Wilson line technique is then implemented to treat the set of next-to-soft contributions arising from dressing external partons with a next-to-soft Wilson line.
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7

Dongxu, Yang. "Novel resists for next generation lithography." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6532/.

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With progress in the semiconductor industry, transistor density on a single computer chip has increased dramatically. This has resulted in a continuous shrinkage of the minimum feature size printed through microlithography technology. Resist, as the pattern recording medium of such printing, has been extensively studied to achieve higher resolution, higher sensitivity and lower line edge roughness. For decades this has been realized through chemical amplification. With the feature size continuously shrinking and the energy of exposure source therefore exceeding the resist ionization threshold, the performance of conventional chemically amplified resists is approaching the limits. Novel high-performance chemically amplified resists or non-chemically amplified resists are urgently needed to meet the requirement of next generation lithography. In this work a negative tone chemically amplified resist system based on a novel method to control the catalytic chain reaction is presented. The method to control the catalytic chain reaction is demonstrated using two model polymer resists. This method is then applied to a fullerene-based molecular resist system and a combination of good industrial compatibility, high resolution and good sensitivity has been achieved in this resist. Through a chromatographic separation, another chemically amplified molecular resist was also developed with further improved performance. An alternative route to sensitivity improvement other than chemical amplification is then introduced and a family of fullerene-based metal containing materials is presented. Lithographic performance is compared between the fullerene-metal resists and their control materials without metal. Using an aberration corrected scanning transmission electron microscope, the distribution of metal in the resist film and its behavior during the lithography process is evaluated and discussed.
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8

Du, Dechuan [Verfasser]. "Nucleon-nucleon scattering process in Lattice Chiral Effective Field Theory approach up to next-to-next-to-next-to-leading order / Dechuan Du." Bonn : Universitäts- und Landesbibliothek Bonn, 2018. http://d-nb.info/1160594236/34.

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9

Manyam, Jedsada. "Novel resist materials for next generation lithography." Thesis, University of Birmingham, 2011. http://etheses.bham.ac.uk//id/eprint/1333/.

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Fullerene derivatives have been demonstrated as negative-tone resists for electron beam lithography with impressive capability for high resolution and high plasma etching resistance, due to their carbon-rich nature. Their primary drawback of extremely poor sensitivity has been addressed by implementation of chemical amplification. A three-component chemically amplified negative-tone resist has been developed via the addition of a photoacid generator and a crosslinker to a fullerene derivative. This thesis work presents a significant extension of the previous work. The resists have undergone comprehensive optimisation, and systematic characterisation of electron beam lithography behaviours. In the first part, a systematic study into chemical amplification of negative-tone fullerene resists through variation of resist composition, additive, and resist processing in order to optimise sensitivity, resolution, line width roughness and etch resistance is presented. Sensitivity of sub 10 C/cm2 at 20 keV, half pitch resolution of 20 nm, a minimum sparse feature linewidth of 12 nm, line width roughness of sub 5 nm, and high etch resistance comparable with a commercial novolac resist have been demonstrated. The second part presents the development of a chemically amplified positive-tone fullerene based resists with the advantage of aqueous base solution development. Their lithographic capability is evaluated and discussed.
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Simpson, Robert E. "Chalcogenide thin film materials for next generation data storage." Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/52041/.

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Data can be stored in the form of amorphous and crystalline marks within a chalcogenide thin film. Commonly Ge. Therefore Ga:La:S:Cu shows potential as a future electrical phase change data storage material.
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11

Manalo, Joseph B. "Ascend Physical Therapy| A Private Practice Clinic for the Next Level." Thesis, California State University, Long Beach, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10605220.

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<p> Perfect economic conditions in the national unemployment rate, healthcare crisis in the medical management of acute and chronic conditions, aging population, and the promotion of an active lifestyle culminate in the need of services for physical therapy to address the medical necessity in the healthcare management of musculoskeletal disorders. A private practice in the City of Redondo Beach is primed to provide the needed services patients are seeking to help address all their musculoskeletal needs and goals. The combination of specialized training, advance education, and excellent patient satisfaction is placing Ascend Physical Therapy at the forefront as the first and best choice for physical therapy. Patient outcomes will exceed expectations and will form a relationship with both patients, provider and referral source that will foster a healthy active lifestyle.</p><p>
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12

Al-Ghazu, Nader. "A Study of the Next WLAN Standard IEEE 802.11ac Physical Layer." Thesis, KTH, Signalbehandling, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-133768.

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This thesis studies the Physical Layer (PHY) of the new IEEE 802.11acWireless Local Access Network (WLAN) standard. The 11ac is built basedon the 11n successful standard. The standard is expected to be completedby the end of 2013. And it promises a Very High Throughput (VHT),and robust communication. In order to achieve that, the 11ac uses morebandwidth, it employs higher numbers of Multiple-Input Multiple-Output(MIMO) spatial streams, and higher orders of modulations. The 11ac PHYframe structure is studied in details. The transmitter and receiver blocks areexplained and implemented by MATLAB. Bit Error Rate (BER) and ErrorVector Magnitude (EVM) simulations of the PHY were run. The effectof different Modulation and Coding Scheme (MCS), and bandwidths werestudied. The performance of MIMO and Space-Time Block Coding (STBC)was investigated. The simulation results shows how the 11ac benefits fromthe new employed features. The created MATLAB simulation program canbe used for further tests and research.
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13

Tuladhar, Aashish. "Structure and Dynamics of Water Next to Mineral Surfaces." Diss., Temple University Libraries, 2016. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/420679.

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Chemistry<br>Ph.D.<br>Vibrational sum frequency generation (vSFG) spectroscopy is a second order non-linear technique that can efficiently and selectively investigate an interface between two media. vSFG spectroscopy has been frequently used to interrogate the mineral/water interface by probing the interfacial O−H stretch, which is an excellent reporter of its hydrogen bonding environment. My work, described in this dissertation, is focused on using steady-state and time-resolved vSFG spectroscopy to understand how (a) the type of mineral, (b) the crystalline faces of the mineral, (c) the surface charge of the mineral, and (d) the ionic strength of the bulk liquid affect the structure and the ultrafast dynamics of the mineral/water interface. The results obtained for alumina/water interface are compared with the more commonly studied silica/water interface. The Al2O3/H2O interface provides an ideal opportunity to study the behavior of water next to a positively charged, neutral, and negatively charged mineral surface since its point of zero charge (PZC) lies near the pH of neutral water (pH 6-8). In contrast, due to its low PZC (~pH 2), silica surface is usually neutral or negatively charged. Additionally, a-alumina is crystalline in structure and can be cut to expose different faces (e.g., 0001, 11 ̅02, 112 ̅0) which has been speculated to uniquely affect the ordering and the hydrogen bonding environment of its adjacent water molecules. Our vSFG spectra of the O-H stretch at the alumina/water interface revealed the presence of highly red-shifted 3000 cm-1 species, which is absent at the silica/water interface. With the help of DFT calculations, we assigned the red-shifted peak to the O-H stretch of strongly hydrogen bonded surface aluminol groups and/or interfacial water molecules that are hydrogen bonded to the mineral surface. The 3000 cm-1 species was present at both the Al2O3(0001) and the Al2O3(112 ̅0) surface, but was more prominent for the latter which resulted in the O-H stretch of the Al2O3(112 ̅0)/H2O interface to appear more red-shifted compared to the Al2O3(0001)/H2O interface. This observation provided us with an experimental evidence that the water next to the Al2O3(112 ̅0) surface is in a stronger hydrogen bonded environment than next to the Al2O3(0001) surface as predicted by Catalano’s X-ray reflectivity measurements. Additionally, IR pump - vSFG probe experiments were used to investigate the ultrafast vibrational dynamics of the O-H stretch at alumina/water interfaces. The vibrational dynamics at the Al2O3(112 ̅0)/H2O interface was observed to be fast (T1 = 100-130 fs) and not affected by the mineral surface charge (controlled by bulk pH) or the ionic strength (up to 0.5 M NaCl). In contrast, for the Al2O3(0001)/H2O interface, the vibrational dynamics was observed to be two times faster for the charged surface (T1 ~ 105 fs) compared to the neutral surface (T1 ~ 220 fs). This result provides further evidence that the water next to the Al2O3(112 ̅0) surface is more ordered and/or strongly hydrogen bonded compared to the water next to the Al2O3(0001) surface. The vibrational dynamics observed at the charged Al2O3(0001)/H2O interface (T1 ~105 fs) is faster than in bulk water and at the charged silica/water interface (T1 = ~200 fs). We speculate that the red-shifted 3000 cm-1 species present at the alumina/water interface plays a major role in the mechanism of vibrational relaxation since the 3000 cm-1 species is present at the alumina/water interface and not at the silica/water interface. The main mechanism of vibrational relaxation of the O-H stretch in bulk water is known to proceed via the Fermi-resonance coupling between the overtone of the water bend and the O-H stretch. The presence of red-shifted O-H species at the alumina/water interface could lead to better coupling between the O-H stretch and the water bend overtone and hence result in faster vibrational relaxation than in bulk water. Alternatively, a new pathway of vibrational relaxation via an ultrafast excited state proton transfer reaction could be operative for the alumina/water interface due to the presence of different types of O-H stretches (arising from aluminol groups and water molecules). Such a mechanism would not be possible at the silica interface due to the significantly lower density of surface bound hydroxyls. We are not able to determine the dominant mechanism for vibrational relaxation at the alumina/water interface with our current experiments and therefore, our future work will involve collaborations with theoretical groups in order to answer this question.<br>Temple University--Theses
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14

Hontz, Michael Robert. "Next Generation Integrated Behavioral and Physics-based Modeling of Wide Bandgap Semiconductor Devices for Power Electronics." University of Toledo / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1556718365514067.

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15

Heymes, David Verfasser], Michal [Akademischer Betreuer] [Czakon, and Werner [Akademischer Betreuer] Bernreuther. "A general subtraction scheme for next to next to leading order computations in perturbative quantum chromodynamics / David Heymes ; Michal Czakon, Werner Bernreuther." Aachen : Universitätsbibliothek der RWTH Aachen, 2015. http://d-nb.info/1128157233/34.

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Heymes, David [Verfasser], Michal [Akademischer Betreuer] Czakon, and Werner [Akademischer Betreuer] Bernreuther. "A general subtraction scheme for next to next to leading order computations in perturbative quantum chromodynamics / David Heymes ; Michal Czakon, Werner Bernreuther." Aachen : Universitätsbibliothek der RWTH Aachen, 2015. http://d-nb.info/1128157233/34.

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17

Chen, Long Verfasser], Werner [Akademischer Betreuer] Bernreuther, and Michal [Akademischer Betreuer] [Czakon. "Heavy Quark-Pair Production in Electron Positron Collisions at Next-to-Next-to-Leading Order QCD / Long Chen ; Werner Bernreuther, Michal Wiktor Czakon." Aachen : Universitätsbibliothek der RWTH Aachen, 2017. http://d-nb.info/1162498927/34.

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18

Banerjee, Archan. "Optimisation of superconducting thin film growth for next generation superconducting detector applications." Thesis, University of Glasgow, 2017. http://theses.gla.ac.uk/8573/.

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There is a growing demand for superconducting detectors with single photon sensitivity from near- to far infrared wavelengths. Emerging application areas include imaging, remote sensing, astronomy and free space communications. Two superconducting device technologies, superconducting nanowire single-photon detectors (SSPDs/SNSPDs) and microwave kinetic inductance detectors (MKIDs) have the potential to outperform off-the-self semiconductor technologies and offer scalability to large arrays. Fabrication of high efficiency superconducting detectors strongly depends on the quality of superconducting thin films. The original work presented in this thesis has explored the growth and optimization of several superconducting thin film materials for next generation superconducting detectors. Films have been grown in an ultra-high vacuum sputter deposition system and an atomic layer deposition system. Since its initial demonstration, NbN and NbTiN have been predominantly used as the base material for SNSPDs. In this work, we have explored the optimization of both the materials with an emphasis on NbTiN. NbTiN is optimized by heating the substrates to 800 ̊C achieving a Tc of 10.4 K for a film thickness of 5.5 nm on silicon substrate. Due to their crystalline nature superconducting properties of NbN or NbTiN thin films are strongly correlated with the lattice parameters of substrate properties. This causes a restriction on the substrate choice and integration of SNSPD devices with complex circuits. Amorphous superconducting materials can be promising alternatives for this purpose. We have explored growth and optimization of amorphous MoSi and MoGe thin films. Both the materials are co-sputtered to tune the composition. For 5 nm thick MoSi film on silicon substrate we obtain Tc of 5.5 K. For MKID fabrication, TiN can be an useful base material due to its high sheet resistance and widely tuneable superconducting properties. TiN thin films have been sputtered on heated (500 ̊C) silicon substrates with a Tc of 3.9 K for a 90 nm thick film. The dielectric constants of the thin films as a function of wavelength (270-2200 nm) have been determined via variable angle spectroscopic ellipsometry (VASE). Atomic structure and stoichiometry of the films have been characterized in high resolution transmission electron microscopy (HRTEM). This study enables us to precisely control film properties and thus tailor superconducting films to the requirements of specific photon-counting applications.
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19

Scannell, Stephen Godfrey. "Next Generation Science Standards and Physics First: a Case Study of High School Teachers' Beliefs and Practices." PDXScholar, 2019. https://pdxscholar.library.pdx.edu/open_access_etds/5002.

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This dissertation is a case study of a school district in the Pacific Northwest that developed three-year high school science curricula using a Physics First course sequence (Physics, Chemistry, Biology), with the crosscutting concept Patterns as the central theme of the courses. The purpose of the study was to examine the impact of the implementation of the 9th grade course, Patterns Physics, on teacher practice and beliefs about science teaching and determine whether this new approach facilitated teacher classroom practices and beliefs congruent with those expressed in A Framework for K-12 Science Education (NRC, 2012) and the Next Generation Science Standards (NGSS Lead States, 2013). Results from this study indicate that the implementation of Patterns Physics positively impacted teacher confidence in teaching the NGSS science and engineering practices. Professional development that provided teachers multiple opportunities to engage with the curriculum--in the role of a student, in professional discussions with colleagues, and over several years were critical to support a change in practice consistent with three-dimensional (3D) teaching called for by the Framework and NGSS. Teacher participants viewed the Patterns PCB (Physics, Chemistry, and Biology) sequence as an appropriate course sequence, with strong agreement that a 9th grade physics course needs to be tailored to the needs of students, such as added support for students with minimal mathematics skills. The NGSS, with an emphasis on 3D learning (science content knowledge, crosscutting concepts, and science and engineering practices), had a significant positive impact on instructional practice.
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Bradley, Frank Mitchell. "Transport imaging for the study of quantum scattering phenomena in next generation Semiconductor devices /." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2005. http://library.nps.navy.mil/uhtbin/hyperion/05Dec%5FBradley.pdf.

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Sun, Yong. "A rigorous physical layer investigation of next generation high performance radio LANs." Thesis, University of Bristol, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390095.

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Prausa, Mario Verfasser], Robert V. [Akademischer Betreuer] [Harlander, and Michal [Akademischer Betreuer] Czakon. "Towards light quark mass effects in Higgs production and decay at next-to-next-to-leading order / Mario Prausa ; Robert Valentin Harlander, Michal Wiktor Czakon." Aachen : Universitätsbibliothek der RWTH Aachen, 2018. http://d-nb.info/1171818564/34.

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Prausa, Mario [Verfasser], Robert V. [Akademischer Betreuer] Harlander, and Michal [Akademischer Betreuer] Czakon. "Towards light quark mass effects in Higgs production and decay at next-to-next-to-leading order / Mario Prausa ; Robert Valentin Harlander, Michal Wiktor Czakon." Aachen : Universitätsbibliothek der RWTH Aachen, 2018. http://d-nb.info/1171818564/34.

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Summ, Benjamin. "Higgs mass calculations in the Next-to-Minimal Supersymmetric Standard Model." Thesis, KTH, Fysik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-212725.

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25

Coull, Jonathan. "Single-particle production and photon-hadron correlations in proton-proton collisions at next-to-leading order." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=104670.

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In this thesis, we study photon production and photon-hadron correlations at next-to-leading order (NLO) in proton-proton collisions, in both the cases of isolated and non-isolated photons. To begin, fundamentals of perturbative Quantum Chromodynamics (pQCD) are reviewed, with an emphasis on describing how to compute spectra for single particle production and correlated pairs at both leading order (LO) and NLO in hadronic collisions. In particular, a discussion of infrared and collinear singularities at NLO will provide a natural introduction to the concept of factorization. These results are then specifically applied to the case of computing photon and pion single-particle cross-sections in proton-proton collisions at Relativistic Heavy-Ion Collider (RHIC) and Large Hadron Collider(LHC) energies, and compared to experimental data from the PHENIX and CMS experiments respectively. Included in this will be a short study of the theoretical systematic uncertainty generated by the dependence on factorization scales, and a discussion of the modifications needed when moving from inclusive to isolated observables. Following this, double inclusive cross-sections for production of photon-tagged hadrons are computed and compared to data from PHENIX. Once again, a full NLO treatment is given, and the effects of isolation are implemented. We will conclude with a final section on the application of photon-hadron correlations to the tomographic mapping of energy loss in heavy-ion collisions.<br>Dans cette dissertation, nous étudions la production au seconde ordre (NLO) de photons ainsi que la corrélation entre photons durs et hadrons dans les collisions proton-proton. Dans les deux cas est inclus l'effet de l'application de critères d'isolement sur les photons. Nous commençons par une synthèse des résultats fondamentaux de la chromodynamique quantique perturbative (pQCD), dans laquelle nous résumons les méthodes principales pour calculer des sections efficaces aux premier et second ordres. En particulier, nous discutons des singularités infrarouges et colinéaires qui se produisent au seconde ordre, ce qui nous amènera à introduire la théorie de la factorisation. Ces outils sont par la suite utilisés pour calculer les section efficaces pour la production de photons et de pions dans les collisions proton-proton aux énergies atteintes au Relativistic Heavy Ion Collider (RHIC)et au Grand collisionneur de hadrons (LHC). Ces résultats sont comparés aux données des expériences PHENIX et CMS respectivement. Nous étudions aussi l'incertitude théorique due aux choix des échelles de factorisation et la différence entre les sections efficaces inclusives et isolées. Finalement, nous calculons les sections efficaces pour les paires photon-hadron corrélées et comparons les résultats aux données de PHENIX, tout en incluant les effets de second ordre et d'isolement. Nous concluons avec une description qualitative de l'application des corrélations pour établir une tomographie des collisions d'ions lourds.
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Marlowe, Hannah Rebecca. "Polarimetric and spectrographic instrumentation to enable next generation x-ray observatories." Diss., University of Iowa, 2016. https://ir.uiowa.edu/etd/3136.

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Ultraluminous X-ray (ULX) sources are non-nuclear extragalactic accreting compact objects whose X-ray luminosities exceed the Eddington limit for stellar mass black hole binaries (BHB). Their high luminosities suggest they are either intermediate mass black holes, that their emission is beamed, or that they are emitting at super-Eddington rates. We observed the ULX IC 342 X-1 simultaneously in X-ray and radio with Chandra and the VLA to investigate previously reported unresolved radio emission coincident with the ULX. The Chandra spectrum appears to be consistent with an accretion disc-dominated thermal state and suggests a mass of the black hole using the modeled inner disc temperature to be 157Mʘ ≤ M √ (cosi) ≤ 200 Mʘ. No significant radio emission was observed, consistent with the source being in a thermal disc-dominated state. Reanalysis of previous X-ray observations of the source shows that high energy curvature often interpreted as evidence for supercritical accretion cannot confidently be identified using the 2-10 keV energy band. Black hole systems such as BHBs, ULXs, and AGN represent the greatest test labs in the universe for the study of extreme gravity. Emission from the accretion disk and scattering from the surrounding corona allow study of the ultra-strong gravity and magnetic fields very near the central BH engine. However, many of these effects are imprinted as polarization of the emission and are invisible to spectral and timing studies alone. The outflows from AGN are also thought to play a key role in galaxy shaping and cluster formation. High efficiency and spectral resolution are required to measure ionization-velocities and density parameters from these sources to constrain the outflow structure. Beamline studies and theoretical modeling were carried out to characterize the throughput and spectral resolving power of off-plane gratings for use in future x-ray observatories which will make these measurements. Additionally, synchrotron measurements were carried out to test theoretical predictions of strong polarization response for off-plane diffraction gratings. The empirical results of this study are the first to demonstrate a lack of polarization sensitivity for grazing-incidence off-plane gratings and support more complex modeling results than used previously.
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Barker, Charles E. "Physical and geochemical conditions of organic metamorphism next to selected dikes, Victoria, Australia /." Title page, contents and abstract only, 1994. http://web4.library.adelaide.edu.au/theses/09PH/09phb2545.pdf.

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Schütte, Dirk [Verfasser]. "Modern control approaches for next-generation interferometric gravitational wave detectors / Dirk Schütte." Hannover : Technische Informationsbibliothek (TIB), 2016. http://d-nb.info/1118739361/34.

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Nguyen, Phuc Bao-Uyen. "Quark mass generation and mixing; and the next-to-leading order QCD calculation for hadron-hadron elastic collisions." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41226.

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This thesis is arranged in two distinct parts. The first part involves the construction of a novel dynamical scheme which is capable of generating the masses of the quarks and the elements of the Kobayashi-Maskawa matrix, and which does not rely upon the Higgs mechanism. The up quarks acquire their masses by coupling to a new heavy fermion via emission and reabsorption of a new scalar boson. The down quarks, on the other hand, obtain their masses via a correction to the up mass matrix as a result of an anomalous flavour changing interaction of the $W sp pm$. Extensions of the mass generation model are proposed and discussed. The second part involves the leading-log s study of hadron-hadron elastic scattering to order $ alpha sb{s} sp3$. By introducing wave functions, it is found that there are three types of form factor for the proton, and two for the pion. These form factors turn out to cancel the infrared divergence which occurs in quark-quark scattering. To this order in $ alpha sb{s}$, the amplitude of such elastic scattering is shown to have the form $ sim$(1 + log(s)($ alpha sb{o}$ + $ alpha sp prime t$ + $O(t sp2))$ for the imaginary part and a constant $ sim alpha sb{odd}$ for the real part, where s and t are the usual Mandelstam variables, and the $ alpha$'s are constants.
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Drechsel, Peter [Verfasser], and Georg [Akademischer Betreuer] Weiglein. "Precise Predictions for Higgs Physics in the Next-to-Minimal Supersymmetric Standard Model (NMSSM) / Peter Drechsel. Betreuer: Georg Weiglein." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2016. http://d-nb.info/1113184388/34.

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Jacqmin, Hermance. "Coherent combining of few-cycle pulses for the next generation of Terawatt-class laser sources devoted to attosecond physics." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLX064/document.

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Cette thèse s’inscrit dans le cadre du développement d’une source laser TW, de cadence élevée, stabilisée en phase, et délivrant des impulsions de quelques cycles optiques pour explorer la physique attoseconde. De telles impulsions contiennent seulement quelques oscillations de l’onde porteuse (durée de 5 fs à une longueur d’onde centrale de 800 nm) et ne sont pas directement disponibles à la sortie d’une source laser femtoseconde classique. Une technique de post-compression efficace pour obtenir de telles impulsions consiste à élargir le spectre des impulsions laser par automodulation de phase dans une fibre creuse remplie de gaz, puis à compenser la phase spectrale introduite avec des miroirs chirpés. Cette technique convient à des impulsions dont l’énergie est inférieure au millijoule. Au-delà, la transmission et la stabilité du compresseur chutent fortement à cause d'effets non linéaires tels que l'autofocalisation et l'ionisation. Pour comprimer des impulsions énergétiques et dont la phase de l’enveloppe est stabilisée par rapport à la porteuse (stabilisation de la CEP), il est possible de diviser l'impulsion initiale en plusieurs répliques d'énergie moindre et de réduire ainsi l'intensité crête en entrée de fibre. Le spectre de chaque réplique est alors élargi indépendamment. Dans le cadre de cette thèse, la combinaison cohérente passive d'impulsions de quelques cycles optiques issues d'une fibre creuse remplie de gaz est démontrée pour la première fois. L'utilisation de lames biréfringentes (calcite) dont l’orientation est soigneusement déterminée permet de générer et combiner des répliques avec une efficacité élevée. Ainsi, dans le cas d’une division en deux répliques, des impulsions stabilisées en phase (CEP), de durée 6 fs et d'énergie 0.6 mJ ont été générées de manière fiable et reproductible. L’étude détaillée de cette technique, aussi bien théorique qu’expérimentale, a permis de mettre en évidence les conditions requises pour générer des impulsions de quelques cycles optiques et présentant un bon contraste temporel. Plus précisément, la phase spectrale relative entre les répliques peut être mesurée à l'aide d'une méthode interférométrique permettant de quantifier les déphasages résiduels dus à la lame qui recombine les répliques, ainsi que ceux induits lors de la propagation dans la fibre par d'éventuels effets de modulation de phase croisée ou d'ionisation. Les effets qui affectent le processus de combinaison des répliques, tels que les modifications des états de polarisation des répliques ou bien les interactions non linéaires entre les répliques, sont analysés en détail. Une méthode est proposée pour minimiser ces effets, même dans le cas plus critique de la division et combinaison d'impulsions à quatre répliques<br>The framework of this thesis is the design and development of a TW-class, high-repetition rate, CEP-stabilized, few-cycle laser system devoted to attosecond physics. Few-cycle pulses includes only a few oscillations of the carrier wave (duration about 5 fs for 800nm central wavelength) and are not directly available at the output of typical femtosecond sources. One of the most popular techniques used for producing such pulses with high spatial quality is nonlinear spectral broadening in a gas-filled hollow-core fiber followed by temporal compression with chirped mirrors. However, as the input pulse energy approaches the milliJoule level, both the transmission and stability of hollow fiber compressors rapidly drop with the onset of self-focusing and ionization. A way of overcoming this limitation is to divide the input pulse into several lower energy replicas that can be subsequently recombined after independent spectral broadening in the fiber. In this thesis, the passive coherent combining of millijoule energy laser pulses down to few-cycle duration in a gas-filled hollow fiber is demonstrated for the first time. High combining efficiency is achieved by using carefully oriented calcite plates for temporal pulse division and recombination. Carrier-envelope phase (CEP)- stable, 6-fs, 800-nm pulses with more than 0.6 mJ energy were routinely generated in the case of twofold division and recombination. A detailed theoretical and experimental analysis of this temporal multiplexing technique is proposed to explain the conditions required for producing few-cycle pulses with high fidelity. In particular, an interferometric method for measuring the relative spectral phase between two replicas is demonstrated. This gives a measure of the phase mismatch in the combining plate, as well as that induced by eventual cross-phase modulation or ionization during propagation in the fiber. The effects degrading the combining process, as polarization change or nonlinear interactions between pulse replicas are analyzed in details. A method is proposed to overcome these limitations, even in the critical case of fourfold pulse division and combination
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Sangel, Marc [Verfasser], Dietrich [Akademischer Betreuer] Bödeker, and Nicolas [Akademischer Betreuer] Borghini. "Next-to-leading order rates in leptogenesis / Marc Sangel ; Dietrich Bödeker, Nicolas Borghini." Bielefeld : Universitätsbibliothek Bielefeld, 2016. http://d-nb.info/1119978025/34.

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Tegfalk, Elin. "Application of machine learning techniques to perform base-calling in next-generation DNA sequencing." Thesis, KTH, Tillämpad fysik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-280487.

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Karthein, Jonas [Verfasser], and Klaus [Akademischer Betreuer] Blaum. "Next-Generation Mass Spectrometry of Exotic Isotopes and Isomers / Jonas Karthein ; Betreuer: Klaus Blaum." Heidelberg : Universitätsbibliothek Heidelberg, 2020. http://d-nb.info/1210647753/34.

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35

Schulte, Lukas [Verfasser]. "Determining the Neutrino Mass Hierarchy with the Precision IceCube Next Generation Upgrade (PINGU) / Lukas Schulte." Bonn : Universitäts- und Landesbibliothek Bonn, 2015. http://d-nb.info/107927328X/34.

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36

Knippen, Gernot [Verfasser], and Stefan [Akademischer Betreuer] Dittmaier. "Next-to-leading-order QCD and electroweak corrections to WWW production at proton–proton colliders." Freiburg : Universität, 2019. http://d-nb.info/1204364532/34.

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Erbing, Axel. "In pursuit of next generation photovoltaics : An electronic structure study of lead-free perovskite solar cells." Licentiate thesis, Stockholms universitet, Fysikum, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-181608.

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The recent development of perovskite-based solar cells have shown a remarkably fast increase in power conversion efficiency making them a promising low-cost alternative to conventional cells. The most successful class of materials however, the lead-halide perovskites, are held back due to toxicity and stability issues significantly limiting their use. Because of this, the investigation of new, lead-free, light-absorber materials as a replacement is an important step towards improved solar cells. The focus of this licentiate thesis is the study of bismuth-based materials and their photovoltaic properties through electronic structure calculations. Specifically, the cubic-phase AgBi2I7 under gradual substitution of either bromine or antimony is investigated using density functional theory under periodic boundary conditions. This enables calculations of the system's energy levels and band structure. Furthermore, the energy variance of the employed model of the system is sampled with respect to its level of ion disorder to obtain a better understanding of the distribution of ions within the crystal. The materials are found to have good optical properties but comparatively low efficiencies. The introduced substitutions allow fine-tuning of the system's band gap and is shown to increase the overall performance of the solar cells. In addition, spin-orbit coupling effects are demonstrated to be important when treating these bismuth-based systems. The crystal structure is found to have a significant preference for separating its silver ions and cation vacancies.
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Munoz, Diego Jose. "Modeling and Simulation of Circumstellar Disks with the Next Generation of Hydrodynamic Solvers." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:11151.

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This thesis is a computational study of circumstellar gas disks, with a special focus on modeling techniques and on numerical methods not only as scientific tools but also as a target of study. In particular, in-depth discussions are included on the main numerical strategy used, namely the moving-mesh method for astrophysical hydrodynamics. In this work, the moving-mesh approach is used to simulate circumstellar disks for the first time.<br>Astronomy
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39

Brown, K. D., and John Klimek. "FLEXIBLE NETWORK TRANSCEIVER NEXT GENERATION TELEMETRY NETWORKING." International Foundation for Telemetering, 2005. http://hdl.handle.net/10150/604877.

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ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada<br>This paper describes the Flexible Telemetry Transceiver (FNT)-a modular, scalable, standards-based, software configurable, microwave wireless telemetry network transceiver. The FNT enables flexible, high-rate, long-range, duplex, network services across multipoint to multipoint wireless channel.
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Buberl, Theresa [Verfasser], and Ferenc [Akademischer Betreuer] Krausz. "Towards next-generation molecular fingerprinting : advancing mid-infrared spectroscopy for biomedical applications / Theresa Buberl ; Betreuer: Ferenc Krausz." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2021. http://d-nb.info/1229835830/34.

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41

Karan, Kanioar [Verfasser]. "Demonstration of a Dual Cavity Configuration for next Generation Light-Shining-Through-a-Wall Experiments / Kanioar Karan." Hannover : Gottfried Wilhelm Leibniz Universität, 2021. http://d-nb.info/1235138518/34.

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42

El, Fatimy Abdelouahad. "Détection et Emission Terahertz par les ondes de plasma dans des transistors HEMT à base d'hétérostructures GaN/AlGaN et InGaAs/InAlAs." Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2007. http://tel.archives-ouvertes.fr/tel-00182726.

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Les détecteurs et émetteurs travaillant dans la gamme dite Terahertz sont très coûteux et onctionnent généralement à basse température. Les Professeurs Dyakonov et Shur ont proposé en 1993 une théorie sur l'instabilité des ondes de plasma dans un gaz d'électrons bidimensionnel. Cette théorie énonce qu'un transistor peut fonctionner comme détecteur ou source Terahertz quand la longueur de grille est de taille nanométrique. Dans ce manuscrit, nous présentons une source de radiation Terahertz par un Transistor HEMT à base de l'hétérostructures GaN/AlGaN, (cohérente), accordable à température ambiante, relativement intense (0.1 NW), de taille nanométrique et peu coûteuse. En second lieu, nous proposons des détecteurs Terahertz basés sur la technologie GaN/AlGaN et InGaAs/InAlAs et accordables à température ambiante. Notre étude, d'intérêt pluridisciplinaire, vise à explorer les limites physiques et technologiques des performances des transistors HEMT sur l'Emission et la Détection de radiation Terahertz. L'estimation du NEP (Noise Equivalent Power) a également été réalisée. D'un point de vue fondamental, cette étude nous permettra de mieux connaître les propriétés de la détection et de l'émission par un gaz d'électrons bidimensionnel par le biais des ondes de plasma.
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de, Varona Ortega Omar [Verfasser]. "Fiber amplifiers at 1.5 μm for laser sources in next-generation gravitational wave detectors / Omar de Varona Ortega". Hannover : Gottfried Wilhelm Leibniz Universität Hannover, 2019. http://d-nb.info/1179909631/34.

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Mitrouskas, David [Verfasser], and Peter [Akademischer Betreuer] Pickl. "Derivation of mean-field equations and next-order corrections for bosons and fermions / David Mitrouskas ; Betreuer: Peter Pickl." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2017. http://d-nb.info/1153712180/34.

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Patil, Crystal L. "Weanling needs and the next pregnancy among the Iraqw of Tanzania." Columbus, Ohio : Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1086190016.

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Thesis (Ph. D.)--Ohio State University, 2004.<br>Title from first page of PDF file. Document formatted into pages; contains xxiv, 271 p.; also includes graphics (some col.). Includes abstract and vita. Advisor: Ivy L. Pike, Dept. of Anthropology. Includes bibliographical references (p. 205-231).
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Hangst, Christian [Verfasser], and M. [Akademischer Betreuer] Mühlleitner. "Matching Squark Production and Decay at Next-to-Leading Order Accuracy with Parton Showers / Christian Hangst. Betreuer: M. Mühlleitner." Karlsruhe : KIT-Bibliothek, 2014. http://d-nb.info/1051848288/34.

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Hekhorn, Felix [Verfasser], and Werner [Akademischer Betreuer] Vogelsang. "Next-to-Leading Order QCD Corrections to Heavy-Flavour Production in Neutral Current DIS / Felix Hekhorn ; Betreuer: Werner Vogelsang." Tübingen : Universitätsbibliothek Tübingen, 2019. http://d-nb.info/1196617104/34.

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48

Mobberley, Sean David. "Quantitative assessment of scatter correction techniques incorporated in next generation dual-source computed tomography." Thesis, The University of Iowa, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=1540384.

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<p> Accurate, cross-scanner assessment of in-vivo air density used to quantitatively assess amount and distribution of emphysema in COPD subjects has remained elusive. Hounsfield units (HU) within tracheal air can be considerably more positive than -1000 HU. With the advent of new dual-source scanners which employ dedicated scatter correction techniques, it is of interest to evaluate how the quantitative measures of lung density compare between dual-source and single-source scan modes. This study has sought to characterize in-vivo and phantom-based air metrics using dual-energy computed tomography technology where the nature of the technology has required adjustments to scatter correction. </p><p> Anesthetized ovine (N=6), swine (N=13: more human-like rib cage shape), lung phantom and a thoracic phantom were studied using a dual-source MDCT scanner (Siemens Definition Flash. Multiple dual-source dual-energy (DSDE) and single-source (SS) scans taken at different energy levels and scan settings were acquired for direct quantitative comparison. Density histograms were evaluated for the lung, tracheal, water and blood segments. Image data were obtained at 80, 100, 120, and 140 kVp in the SS mode (B35f kernel) and at 80, 100, 140, and 140-Sn (tin filtered) kVp in the DSDE mode (B35f and D30f kernels), in addition to variations in dose, rotation time, and pitch. To minimize the effect of cross-scatter, the phantom scans in the DSDE mode was obtained by reducing the tube current of one of the tubes to its minimum (near zero) value.</p><p> When using image data obtained in the DSDE mode, the median HU values in the tracheal regions of all animals and the phantom were consistently closer to -1000 HU regardless of reconstruction kernel (chapters 3 and 4). Similarly, HU values of water and blood were consistently closer to their nominal values of 0 HU and 55 HU respectively. When using image data obtained in the SS mode the air CT numbers demonstrated a consistent positive shift of up to 35 HU with respect to the nominal -1000 HU value. In vivo data demonstrated considerable variability in tracheal, influenced by local anatomy with SS mode scanning while tracheal air was more consistent with DSDE imaging. Scatter effects in the lung parenchyma differed from adjacent tracheal measures.</p><p> In summary, data suggest that enhanced scatter correction serves to provide more accurate CT lung density measures sought to quantitatively assess the presence and distribution of emphysema in COPD subjects. Data further suggest that CT images, acquired without adequate scatter correction, cannot be corrected by linear algorithms given the variability in tracheal air HU values and the independent scatter effects on lung parenchyma.</p>
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Riedl, Johann [Verfasser], and Andreas [Akademischer Betreuer] Schäfer. "Spin-dependent hadro- and photoproduction of heavy quarks at next-to-leading order of QCD / Johann Riedl. Betreuer: Andreas Schäfer." Regensburg : Universitätsbibliothek Regensburg, 2014. http://d-nb.info/1050591976/34.

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Bonetti, Marco [Verfasser], and K. [Akademischer Betreuer] Melnikov. "Next-to-leading order mixed QCD-electroweak corrections to Higgs boson production in gluon fusion / Marco Bonetti ; Betreuer: K. Melnikov." Karlsruhe : KIT-Bibliothek, 2019. http://d-nb.info/119237357X/34.

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