Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Engineering (6652)
- Physical Sciences and Mathematics (2969)
- Civil and Environmental Engineering (2149)
- Electrical and Computer Engineering (1607)
- Physics (1115)
-
- Geotechnical Engineering (1068)
- Computer Sciences (917)
- Chemical Engineering (790)
- Mechanical Engineering (651)
- Materials Science and Engineering (611)
- Chemistry (488)
- Structural Engineering (430)
- Civil Engineering (358)
- Aerospace Engineering (327)
- Earth Sciences (314)
- Mining Engineering (313)
- Operations Research, Systems Engineering and Industrial Engineering (295)
- Geology (270)
- Metallurgy (260)
- Petroleum Engineering (251)
- Biochemical and Biomolecular Engineering (187)
- Ceramic Materials (185)
- Architecture (172)
- Architectural Engineering (166)
- Social and Behavioral Sciences (164)
- Mathematics (155)
- Statistics and Probability (145)
- Geological Engineering (142)
- Nuclear Engineering (133)
- Geophysics and Seismology (121)
- Keyword
-
- Machine learning (38)
- Quantum Theory (36)
- Neural Nets (32)
- Electrodynamics (31)
- Hydrogen (29)
-
- Deep learning (27)
- Neural Networks (27)
- Ionization (26)
- Voltage Control (26)
- Machine Learning (25)
- Neurocontrollers (25)
- Mathematical Models (24)
- Simulation (24)
- Electrons (23)
- Power Electronics (23)
- Power System Control (23)
- Atoms (22)
- Electromagnetic Interference (22)
- Modeling (22)
- Security (22)
- Stability (22)
- Algorithms (21)
- Learning (Artificial Intelligence) (21)
- Photons (21)
- Electromagnetic Compatibility (20)
- Optimal Control (20)
- Article (19)
- Helium (19)
- Classification (18)
- DC-DC Power Convertors (18)
- Publication Year
- Publication
-
- Masters Theses (2098)
- The Missouri Miner Newspaper (1109)
- Electrical and Computer Engineering Faculty Research & Creative Works (1019)
- Doctoral Dissertations (952)
- Physics Faculty Research & Creative Works (868)
-
- International Conference on Case Histories in Geotechnical Engineering (545)
- International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics (512)
- Computer Science Faculty Research & Creative Works (388)
- Chemistry Faculty Research & Creative Works (316)
- Civil, Architectural and Environmental Engineering Faculty Research & Creative Works (314)
- Mechanical and Aerospace Engineering Faculty Research & Creative Works (308)
- Materials Science and Engineering Faculty Research & Creative Works (221)
- Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works (214)
- CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018) (207)
- Chemical and Biochemical Engineering Faculty Research & Creative Works (190)
- Computer Science Technical Reports (147)
- Engineering Management and Systems Engineering Faculty Research & Creative Works (139)
- Missouri S&T Magazine (106)
- Professional Degree Theses (105)
- UMR-MEC Conference on Energy / UMR-DNR Conference on Energy (100)
- Mathematics and Statistics Faculty Research & Creative Works (92)
- Opportunities for Undergraduate Research Experience Program (OURE) (78)
- Bachelors Theses (72)
- Symposia on Turbulence in Liquids (70)
- CCFSS Library (1939 - present) (68)
- American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present) (61)
- Biological Sciences Faculty Research & Creative Works (56)
- Mining Engineering Faculty Research & Creative Works (55)
- Business and Information Technology Faculty Research & Creative Works (48)
- Minutes & Agendas (44)
Articles 2041 - 2070 of 10898
Full-Text Articles in Entire DC Network
The Role Of Ceramic And Glass Science Research In Meeting Societal Challenges: Report From An Nsf-Sponsored Workshop, Katherine T. Faber, Tewodros Asefa, Monika Backhaus-Ricoult, Richard K. Brow, Julie Y. Chan, Shen Dillon, William Fahrenholtz, For Full List Of Authors, See Publisher's Website.
The Role Of Ceramic And Glass Science Research In Meeting Societal Challenges: Report From An Nsf-Sponsored Workshop, Katherine T. Faber, Tewodros Asefa, Monika Backhaus-Ricoult, Richard K. Brow, Julie Y. Chan, Shen Dillon, William Fahrenholtz, For Full List Of Authors, See Publisher's Website.
Materials Science and Engineering Faculty Research & Creative Works
Under the sponsorship of the U.S. National Science Foundation, a workshop on emerging research opportunities in ceramic and glass science was held in September 2016. Reported here are proceedings of the workshop. The report details eight challenges identified through workshop discussions: Ceramic processing: Programmable design and assembly; The defect genome: Understanding, characterizing, and predicting defects across time and length scales; Functionalizing defects for unprecedented properties; Ceramic flatlands: Defining structure-property relations in free-standing, supported, and confined two-dimensional ceramics; Ceramics in the extreme: Discovery and design strategies; Ceramics in the extreme: Behavior of multimaterial systems; Understanding and exploiting glasses and melts under …
The Role Of Urinary Pteridines As Disease Biomarkers, Casey Burton, Yinfa Ma
The Role Of Urinary Pteridines As Disease Biomarkers, Casey Burton, Yinfa Ma
Chemistry Faculty Research & Creative Works
Pteridines and their derivatives function as intermediates in the metabolism of several vitamins and cofactors, and their relevance to disease has inspired new efforts to study their roles as disease biomarkers. Recent analytical advances, such as the emergence of sensitive mass spectrometry techniques, new workflows for measuring pteridine derivatives in their native oxidation states and increased multiplexing capacities for the simultaneous determination of many pteridine derivatives, have enabled researchers to explore the roles of urinary pteridines as disease biomarkers at much lower levels with greater accuracy than with previous technologies or methods. As a result, urinary pteridines are being increasingly …
Faculty Senate Minutes Apr. 20, 2017, Missouri University Of Science And Technology Faculty Senate
Faculty Senate Minutes Apr. 20, 2017, Missouri University Of Science And Technology Faculty Senate
Minutes & Agendas
No abstract provided.
Early Detection Of Diseases Using Electronic Health Records Data And Covariance-Regularized Linear Discriminant Analysis, Jiang Bian, Laura E. Barnes, Guanling Chen, Haoyi Xiong
Early Detection Of Diseases Using Electronic Health Records Data And Covariance-Regularized Linear Discriminant Analysis, Jiang Bian, Laura E. Barnes, Guanling Chen, Haoyi Xiong
Computer Science Faculty Research & Creative Works
The availability of Electronic Health Records (EHR) in health care settings provides terrific opportunities for early detection of patients' potential diseases. While many data mining tools have been adopted for EHR-based disease early detection, Linear Discriminant Analysis (LDA) is one of the most widely used statistical prediction methods. To improve the performance of LDA for early detection of diseases, we proposed to leverage CRDA - Covariance-Regularized LDA classifiers on top of diagnosis-frequency vector data representation. Specifically, CRDA employs a sparse precision matrix estimator derived based on graphical lasso to boost the accuracy of LDA classifiers. Algorithm analysis demonstrates that the …
The Missouri Miner, April 6, 2017
Long-Range Tails In Van Der Waals Interactions Of Excited-State And Ground-State Atoms, Ulrich D. Jentschura, V. Debierre
Long-Range Tails In Van Der Waals Interactions Of Excited-State And Ground-State Atoms, Ulrich D. Jentschura, V. Debierre
Physics Faculty Research & Creative Works
A quantum electrodynamic calculation of the interaction of an excited-state atom with a ground-state atom is performed. For an excited reference state and a lower-lying virtual state, the contribution to the interaction energy naturally splits into a pole term and a Wick-rotated term. The pole term is shown to dominate in the long-range limit, altering the functional form of the interaction from the retarded 1/R7 Casimir-Polder form to a long-range tail - provided by the Wick-rotated term - proportional to cos[2(Em - En)R/(ħc)]/R2, where Em < En is the energy of a virtual state, …
Search For Continuous Gravitational Waves From Neutron Stars In Globular Cluster Ngc 6544, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Search For Continuous Gravitational Waves From Neutron Stars In Globular Cluster Ngc 6544, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We describe a directed search for continuous gravitational waves in data from the sixth initial LIGO science run. The target was the nearby globular cluster NGC 6544 at a distance of ≈2.7 kpc. The search covered a broad band of frequencies along with first and second frequency derivatives for a fixed sky position. The search coherently integrated data from the two LIGO interferometers over a time span of 9.2 days using the matched-filtering F-statistic. We found no gravitational-wave signals and set 95% confidence upper limits as stringent as 6.0 x 10-25 on intrinsic strain and 8.5 x 10 …
The Missouri Miner, March 23, 2017
The Missouri Miner, March 15, 2017
Multifunctional Porous Aramids (Aerogels), Fabrication Thereof, And Catalytic Compositions Derived Therefrom, Nicholas Leventis, Chariklia Sotiriou-Leventis, Malik Adnan Saeed
Multifunctional Porous Aramids (Aerogels), Fabrication Thereof, And Catalytic Compositions Derived Therefrom, Nicholas Leventis, Chariklia Sotiriou-Leventis, Malik Adnan Saeed
Chemistry Faculty Research & Creative Works
The present disclosure provides a series of new and improved porous polyamide aerogels derived from multifunctional aromatics that combine the high mechanical strength of aramids with the pore structure of aerogels. The polyamide aerogels have a hyperbranched structure, relatively low density, high porosity and may be derived from functionalized monomers having more aromatic groups than functional groups. The present disclosure also provides a new method for producing the porous polyamide aerogels by polymerizing an aromatic multifunctional carboxylic acid or a ferrocene multifunctional carboxylic acid with a polyfunctional aromatic isocyanate at moderate reaction conditions followed by drying with liquid CO2. Also …
The Missouri Miner, March 9, 2017
Evaluation Of Procedures To Quantify Solvent Retention In Electrospun Fibers And Facilitate Solvent Removal, Anthony R. D'Amato, Nicholas J. Schaub, Jesus M. Cardenas, Erich Franz, Deniz Rende, Alexis M. Ziemba, Ryan J. Gilbert
Evaluation Of Procedures To Quantify Solvent Retention In Electrospun Fibers And Facilitate Solvent Removal, Anthony R. D'Amato, Nicholas J. Schaub, Jesus M. Cardenas, Erich Franz, Deniz Rende, Alexis M. Ziemba, Ryan J. Gilbert
Chemical and Biochemical Engineering Faculty Research & Creative Works
Electro spun fiber scaffolds crafted from polyesters are studied extensively for potential tissue engineering applications. For translation of electro spun fibers into the clinic, the FDA requires analysis and quantification of any organic solvent that may be retained in the fibers since many organic solvents can negatively affect cells and tissues. If a significant amount of solvent is retained, then developing procedures for efficient solvent removal may enhance the clinical potential of these materials. In this study we use fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and nuclear magnetic resonance spectroscopy (NMR) to analyze solvent retention. A correlative analysis …
Missouri S&T Magazine Spring 2017, Missouri S&T Marketing And Communications Department, Miner Alumni Association
Missouri S&T Magazine Spring 2017, Missouri S&T Marketing And Communications Department, Miner Alumni Association
Missouri S&T Magazine
No abstract provided.
Using Mobile Sensing To Test Clinical Models Of Depression, Social Anxiety, State Affect, And Social Isolation Among College Students, Philip I. Chow, Karl Fua, Yu Huang, Wesley Bonelli, Haoyi Xiong, Laura E. Barnes, Bethany A. Teachman
Using Mobile Sensing To Test Clinical Models Of Depression, Social Anxiety, State Affect, And Social Isolation Among College Students, Philip I. Chow, Karl Fua, Yu Huang, Wesley Bonelli, Haoyi Xiong, Laura E. Barnes, Bethany A. Teachman
Computer Science Faculty Research & Creative Works
Background: Research in psychology demonstrates a strong link between state affect (moment-to-moment experiences of positive or negative emotionality) and trait affect (e.g., relatively enduring depression and social anxiety symptoms), and a tendency to withdraw (e.g., spending time at home). However, existing work is based almost exclusively on static, self-reported descriptions of emotions and behavior that limit generalizability. Despite adoption of increasingly sophisticated research designs and technology (e.g., mobile sensing using a global positioning system [GPS]), little research has integrated these seemingly disparate forms of data to improve understanding of how emotional experiences in everyday life are associated with time spent …
Estimating The Permanent Loss Of Groundwater Storage In The Southern San Joaquin Valley, California, Ryan G. Smith, Rosemary Knight, J. Chen, J. A. Reeves, H. A. Zebker, T. Farr, Z. Liu
Estimating The Permanent Loss Of Groundwater Storage In The Southern San Joaquin Valley, California, Ryan G. Smith, Rosemary Knight, J. Chen, J. A. Reeves, H. A. Zebker, T. Farr, Z. Liu
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
In the San Joaquin Valley, California, recent droughts starting in 2007 have increased the pumping of groundwater, leading to widespread subsidence. In the southern portion of the San Joaquin Valley, vertical subsidence as high as 85 cm has been observed between June 2007 and December 2010 using Interferometric Synthetic Aperture Radar (InSAR). This study seeks to map regions where inelastic (not recoverable) deformation occurred during the study period, resulting in permanent compaction and loss of groundwater storage. We estimated the amount of permanent compaction by incorporating multiple data sets: the total deformation derived from InSAR, estimated skeletal-specific storage and hydraulic …
Seismic Azimuthal Anisotropy Beneath The Eastern United States And Its Geodynamic Implications, Bin B. Yang, Yunhua Liu, Haider Dahm, Kelly H. Liu, Stephen S. Gao
Seismic Azimuthal Anisotropy Beneath The Eastern United States And Its Geodynamic Implications, Bin B. Yang, Yunhua Liu, Haider Dahm, Kelly H. Liu, Stephen S. Gao
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Systematic spatial variations of anisotropic characteristics are revealed beneath the eastern U.S. using seismic data recorded between 1988 and 2016 by 785 stations. The resulting fast polarization orientations of the 5613 measurements are generally subparallel to the absolute plate motion (APM) and are inconsistent with the strike of major tectonic features. This inconsistency, together with the results of depth estimation using the spatial coherency of the splitting parameters, suggests a mostly asthenospheric origin of the observed azimuthal anisotropy. The observations can be explained by a combined effect of APM-induced mantle fabric and a flow system deflected horizontally around the edges …
Calibration Of The Advanced Ligo Detectors For The Discovery Of The Binary Black-Hole Merger Gw150914, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Calibration Of The Advanced Ligo Detectors For The Discovery Of The Binary Black-Hole Merger Gw150914, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
In Advanced LIGO, detection and astrophysical source parameter estimation of the binary black hole merger GW150914 requires a calibrated estimate of the gravitational-wave strain sensed by the detectors. Producing an estimate from each detector's differential arm length control loop readout signals requires applying time domain filters, which are designed from a frequency domain model of the detector's gravitational-wave response. The gravitational-wave response model is determined by the detector's opto-mechanical response and the properties of its feedback control system. The measurements used to validate the model and characterize its uncertainty are derived primarily from a dedicated photon radiation pressure actuator, with …
Virtual Resonant Emission And Oscillatory Long-Range Tails In Van Der Waals Interactions Of Excited States: Qedtreatment And Applications, Ulrich D. Jentschura, Chandra Mani Adhikari, Vincent Debierre
Virtual Resonant Emission And Oscillatory Long-Range Tails In Van Der Waals Interactions Of Excited States: Qedtreatment And Applications, Ulrich D. Jentschura, Chandra Mani Adhikari, Vincent Debierre
Physics Faculty Research & Creative Works
We report on a quantum electrodynamic (QED) investigation of the interaction between a ground state atom with another atom in an excited state. General expressions, applicable to any atom, are indicated for the long-range tails that are due to virtual resonant emission and absorption into and from vacuum modes whose frequency equals the transition frequency to available lower-lying atomic states. For identical atoms, one of which is in an excited state, we also discuss the mixing term that depends on the symmetry of the two-atom wave function (these evolve into either the gerade or the ungerade state for close approach), …
Real-Time Flood Forecasting And Information System For The State Of Iowa, Witoldld F. Krajewski, Daniel Ceynar, Ibrahim Demir, Radoslaw Goska, Anton Kruger, Carmen Langel, Ricardo Mantilllla, James Niemeier, Felipe Quintero, Bong Chul Seo, Scott J. Smallll, Larry J. Weber, Nathan C. Young
Real-Time Flood Forecasting And Information System For The State Of Iowa, Witoldld F. Krajewski, Daniel Ceynar, Ibrahim Demir, Radoslaw Goska, Anton Kruger, Carmen Langel, Ricardo Mantilllla, James Niemeier, Felipe Quintero, Bong Chul Seo, Scott J. Smallll, Larry J. Weber, Nathan C. Young
Civil, Architectural and Environmental Engineering Faculty Research & Creative Works
Iowa Flood Center's automated real-time flood forecasting and information system serves as a complement to the National Water Center's proposed national system.
Hadoop-Based Replica Exchange Over Heterogeneous Distributed Cyberinfrastructures, Richard Platania, Shayan Shams, Chui Hui Chiu, Nayong Kim, Joohyun Kim, Seung Jong Park
Hadoop-Based Replica Exchange Over Heterogeneous Distributed Cyberinfrastructures, Richard Platania, Shayan Shams, Chui Hui Chiu, Nayong Kim, Joohyun Kim, Seung Jong Park
Computer Science Faculty Research & Creative Works
We present Hadoop-based replica exchange (HaRE), a Hadoop-based implementation of the replica exchange scheme developed primarily for replica exchange statistical temperature molecular dynamics, an example of a large-scale, advanced sampling molecular dynamics simulation. By using Hadoop as a framework and the MapReduce model for driving replica exchange, an efficient task-level parallelism is introduced to replica exchange statistical temperature molecular dynamics simulations. In order to demonstrate this, we investigate the performance of our application over various distributed cyberinfrastructures (DCI), including several high-performance computing systems, our cyberinfrastructure for reconfigurable optical networks testbed, the global environment for network innovations testbed, and the CloudLab …
The Missouri Miner, February 23, 2017
The Missouri Miner, February 23, 2017
The Missouri Miner Newspaper
No abstract provided.
Faculty Senate Minutes Feb. 23, 2017, Missouri University Of Science And Technology Faculty Senate
Faculty Senate Minutes Feb. 23, 2017, Missouri University Of Science And Technology Faculty Senate
Minutes & Agendas
No abstract provided.
Surrogate Modeling Of Ultrasonic Simulations Using Data-Driven Methods, Xiaosong Du, Robert Grandin, Leifur Leifsson
Surrogate Modeling Of Ultrasonic Simulations Using Data-Driven Methods, Xiaosong Du, Robert Grandin, Leifur Leifsson
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Ultrasonic testing (UT) is used to detect internal flaws in materials and to characterize material properties. In many applications, computational simulations are an important part of the inspection-design and analysis processes. Having fast surrogate models for UT simulations is key for enabling efficient inverse analysis and model-assisted probability of detection (MAPOD). In many cases, it is impractical to perform the aforementioned tasks in a timely manner using current simulation models directly. Fast surrogate models can make these processes computationally tractable. This paper presents investigations of using surrogate modeling techniques to create fast approximate models of UT simulator responses. In particular, …
Characterization And Fracture Property Of Different Strontium-Containing Borate-Based Glass Coatings For Ti6al4v Substrates, Yiming Li, Ali Matinmanesh, Declan J. Curran, Emil H. Schemitsch, Paul Zalzal, Marcello Papini, Anthony W. Wren, Mark R. Towler
Characterization And Fracture Property Of Different Strontium-Containing Borate-Based Glass Coatings For Ti6al4v Substrates, Yiming Li, Ali Matinmanesh, Declan J. Curran, Emil H. Schemitsch, Paul Zalzal, Marcello Papini, Anthony W. Wren, Mark R. Towler
Chemical and Biochemical Engineering Faculty Research & Creative Works
This work considered the effect of increasing Strontium ion (Sr2+) content on the structure of a series of glasses based on the B2O3-P2O5-CaCO3-Na2CO3-TiO2-SrCO3 series and their resultant fracture toughness when coated onto a surgical metal substrate. Six glasses with increasing Sr2+ content (0 to 25 mol%) were synthesized and subsequently characterized by X-ray Diffraction (XRD), Differential Thermal Analysis (DTA) and both Magic Angle Spinning Nuclear Magnetic Resonance (MAS-NMR) and Raman Spectroscopy. These techniques confirmed that increased Sr2+ content induced …
A Novel Tantalum-Containing Bioglass. Part Ii. Development Of A Bioadhesive For Sternal Fixation And Repair, Adel Mf Alhalawani, Cina Mehrvar, Wendy Stone, Stephen D. Waldman, Mark R. Towler
A Novel Tantalum-Containing Bioglass. Part Ii. Development Of A Bioadhesive For Sternal Fixation And Repair, Adel Mf Alhalawani, Cina Mehrvar, Wendy Stone, Stephen D. Waldman, Mark R. Towler
Chemical and Biochemical Engineering Faculty Research & Creative Works
With over a million median sternotomy surgeries performed worldwide every year, sternal wound complications have posed a serious risk to the affected patients. A rigid therapeutic sternal fixation device has therefore become a necessity. In this work, the incorporation of up to 0.5 mol% of tantalum pentoxide (Ta2O5), in exchange for zinc oxide (ZnO), into the SiO2-ZnO-CaO-SrO-P2O5 glass system is presented. The effect of Ta incorporation on the physical, chemical and biological properties of the glass polyalkenoate cements (GPCs) prepared from them have been presented in this manuscript. The data obtained …
Influence Of Permanent Dipole And Dynamic Core-Electron Polarization On Tunneling Ionization Of Polar Molecules, Van-Hung Hoang, Song-Feng Zhao, Van-Hoang Le, Anh-Thu Le
Influence Of Permanent Dipole And Dynamic Core-Electron Polarization On Tunneling Ionization Of Polar Molecules, Van-Hung Hoang, Song-Feng Zhao, Van-Hoang Le, Anh-Thu Le
Physics Faculty Research & Creative Works
We present a detailed theoretical investigation on strong-field ionization of polar (CO and NO) as well as nonpolar molecules (N₂, O₂, and CO₂). Our results indicate that accounting for the Stark correction in the molecular tunneling ionization theory leads to overall fairly good agreements with numerical solutions of the time-dependent Schrödinger equation. Furthermore, we show that the effect of dynamic core-electron polarization, in general, has a weak influence on the angle-dependent ionization probability. However, in the case of CO we confirm the recent finding by B. Zhang, J. Yuan, and Z. Zhao [Phys. Rev. Lett. 111, 163001 (2013)PRLTAO0031-900710.1103/PhysRevLett.111.163001] that accounting …
All-Sky Search For Short Gravitational-Wave Bursts In The First Advanced Ligo Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
All-Sky Search For Short Gravitational-Wave Bursts In The First Advanced Ligo Run, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We present the results from an all-sky search for short-duration gravitational waves in the data of the first run of the Advanced LIGO detectors between September 2015 and January 2016. The search algorithms use minimal assumptions on the signal morphology, so they are sensitive to a wide range of sources emitting gravitational waves. The analyses target transient signals with duration ranging from milliseconds to seconds over the frequency band of 32 to 4096 Hz. The first observed gravitational-wave event, GW150914, has been detected with high confidence in this search; the other known gravitational-wave event, GW151226, falls below the search's sensitivity. …
Long-Range Interactions Of Hydrogen Atoms In Excited States. I. 2s-1s Interactions And Dirac-Δ Perturbations, Chandra Mani Adhikari, Vincent Debierre, Arthur N. Matveev, Nikolai N. Kolachevsky, Ulrich D. Jentschura
Long-Range Interactions Of Hydrogen Atoms In Excited States. I. 2s-1s Interactions And Dirac-Δ Perturbations, Chandra Mani Adhikari, Vincent Debierre, Arthur N. Matveev, Nikolai N. Kolachevsky, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
The theory of the long-range interaction of metastable excited atomic states with ground-state atoms is analyzed. We show that the long-range interaction is essentially modified when quasidegenerate states are available for virtual transitions. A discrepancy in the literature regarding the van der Waals coefficient C6 (2S ;1 S ) describing the interaction of metastable atomic hydrogen ( 2 S state) with a ground-state hydrogen atom is resolved. In the the van der Waals range a0 ≪ R ≪ a0 / α , where a0 = ℏ / α m c is the Bohr radius and α …
Long-Range Interactions Of Hydrogen Atoms In Excited States. Ii. Hyperfine-Resolved 2s-2s Systems, Ulrich D. Jentschura, Vincent Debierre, Chandra Mani Adhikari, Arthur N. Matveev, Nikolai N. Kolachevsky
Long-Range Interactions Of Hydrogen Atoms In Excited States. Ii. Hyperfine-Resolved 2s-2s Systems, Ulrich D. Jentschura, Vincent Debierre, Chandra Mani Adhikari, Arthur N. Matveev, Nikolai N. Kolachevsky
Physics Faculty Research & Creative Works
The interaction of two excited hydrogen atoms in metastable states constitutes a theoretically interesting problem because of the quasidegenerate 2P1/2 levels that are removed from the 2S states only by the Lamb shift. The total Hamiltonian of the system is composed of the van der Waals Hamiltonian, the Lamb shift, and the hyperfine effects. The van der Waals shift becomes commensurate with the 2S-2P3/2 fine-structure splitting only for close approach (R < 100a0, where a0 is the Bohr radius) and one may thus restrict the discussion to the levels with n = 2 and J = 1/2 …
Monte Carlo Simulations Of The Disordered Three-Color Quantum Ashkin-Teller Chain, Ahmed K. Ibrahim, Thomas Vojta
Monte Carlo Simulations Of The Disordered Three-Color Quantum Ashkin-Teller Chain, Ahmed K. Ibrahim, Thomas Vojta
Physics Faculty Research & Creative Works
We investigate the zero-temperature quantum phase transitions of the disordered three-color quantum Ashkin-Teller spin chain by means of large-scale Monte Carlo simulations. We find that the first-order phase transitions of the clean system are rounded by the quenched disorder. For weak intercolor coupling, the resulting emergent quantum critical point between the paramagnetic phase and the magnetically ordered Baxter phase is of infinite-randomness type and belongs to the universality class of the random transverse-field Ising model, as predicted by recent strong-disorder renormalization group calculations. We also find evidence for unconventional critical behavior in the case of strong intercolor coupling, even though …