cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The Relationship Between the Economic Surplus and Production Function Approaches for Estimating Ex-Post Returns to Agricultural Research
Creators: name: Davis, Jeffrey S.
name: Davis, Jeffrey S.
Publisher: name: Unknown
Year: 1981
Subjects: Research and Development/Tech Change/Emerging Technologies

description: The objective of this paper is to develop the conceptual linkage between the production function and economic surplus approaches used to evaluate the returns to agricultural research. First it is established that, for the Cobb-Douglas functional form generally used, an increase in research expenditure will result in a pivotal divergent shift in the supply function. It is then shown that the measure of this change in economic surplus is approximately the same as the value marginal product. Finally it is concluded that if the other possible types of supply shifts, that is, proportional divergent, parallel or convergent, are appropriate, then the production function approach will under-estimate the benefits and therefore rate of return to research expenditure.
A fully differential SMEFT analysis of the golden channel using the method of moments
Creators: name: Banerjee, Shankha
name: Gupta, Rick S.
name: Ochoa-Valeriano, Oscar
name: Spannowsky, Michael
name: Venturini, Elena
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The Method of Moments is a powerful framework to disentangle the relative contributions of amplitudes of a specific process to its various phase space regions. We apply this method to carry out a fully differential analysis of the Higgs decay channel $h \to 4\ell$ and constrain gauge-Higgs coupling modifications parametrised by dimension-six effective operators. We find that this analysis approach provides very good constraints and minimises degeneracies in the parameter space of the effective theory. By combining the decay $h \to 4\ell$ with Higgs-associated production processes, $Wh$ and $Zh$, we obtain the strongest reported bounds on anomalous gauge-Higgs couplings.
description: v2: 32 pages, 6 figures, 2 tables, minor changes: references added, some numbers updated, conclusions unchanged; version accepted for publication in JHEP
Packet loss effects on the quality of MPEG-2 video transported over IP networks
Creators: name: Chiu, Daniel
Publisher: name: University of British Columbia
Year: 2009

description: In this thesis, we examine the effects of packet loss on the quality of the MPEG-2 video transported over an IP network. We performed experiments in a video-ondemand testbed network using three constant bit rate MPEG-2 video elementary streams of differing activity levels. We assessed the video quality using the objective peak signal to noise ratio (PSNR) metric and the subjective mean opinion score (MOS) metric. Our results confirmed that the objective PSNR video quality metric is poorly correlated with subjective quality assessments. We found that the activity level of the video influences the subjective MOS video quality assessments but not the objective PSNR quality measurements. The difference in the perceived video quality between the activity streams was found to be attributed to characteristics in the human visual system. In particular, a high temporal frequency decreases the sensitivity of the visual system. We found that slice loss is linearly correlated with packet loss while picture header loss is poorly correlated with packet loss. We also found that slice loss is the dominant factor contributing to the degradation in video quality rather than picture header loss. We found that low packet loss rates translate into much higher frame error rates due to propagation of errors. Finally, we investigated the effectiveness of forward error correction (FEC) using Reed-Solomon coding on the video quality. We found that FEC can increase a stream's packet loss rate tolerance significantly with a small increase in overhead.
EVALUATION OF COMPOST TOPDRESSING, COMPOST TEA AND CULTIVATION ON TALL FESCUE QUALITY, SOIL PHYSICAL PROPERTIES AND SOIL MICROBIAL ACTIVITY
Creators: name: Chen, Siqi
Publisher: name: Digital Repository at the University of Maryland
Year: 2015
Subjects: subject: Plant sciences
subject: Agriculture
subject: Soil sciences
subject: compost tea
subject: compost topdressing
subject: cultivation
subject: soil microbial activity
subject: soil physical properties
subject: tall fescue

description: Compost topdressing, compost tea, and hollow tine cultivation are common cultural practices employed in organic lawn care programs. Restrictions on the amount of bagged fertilizer nitrogen and phosphorus applied to turf have raised questions about the need to place similar restrictions on compost turfgrass applications.  In a three-year study the effect of reduced and common practitioner use rates of compost topdressing, the use of compost tea and of hollow tine cultivation on soil physical and biological properties and turfgrass quality were evaluated. Cultivation, monthly compost tea application and compost topdressing applied at rates consistent with annual bagged fertilizer nitrogen restrictions had little effect on soil organic matter, microbial activity, bulk density and infiltration. The use of a synthetic fertilizer resulted in higher turf quality than the use of compost on most evaluation dates. Nutrient fertilizer restrictions if applied to compost will likely result in a decline in turf quality.
Microwave Photon Number Resolving Detector Using the Topological Surface State of Superconducting Cadmium Arsenide
Creators: name: Chatterjee, Eric
name: Pan, Wei
name: Soh, Daniel
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Instrumentation and Detectors (physics.ins-det)
subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Photon number resolving detectors play a central role in quantum optics. A key challenge in resolving the number of absorbed photons in the microwave frequency range is finding a suitable material that provides not only an appropriate band structure for absorbing low-energy photons but also a means of detecting a discrete photoelectron excitation. To this end, we propose to measure the temperature gain after absorbing a photon using superconducting cadmium arsenide (Cd3As2) with a topological semimetallic surface state as the detector. The surface electrons absorb the incoming photons and then transfer the excess energy via heat to the superconducting bulk's phonon modes. The temperature gain can be determined by measuring the change in the zero-bias bulk resistivity, which does not significantly affect the lattice dynamics. Moreover, the obtained temperature gain scales discretely with the number of absorbed photons, enabling a photon-number resolving function. Here, we will calculate the temperature increase as a function of the number and frequency of photons absorbed. We will also derive the timescale for the heat transfer process from the surface electrons to the bulk phonons. We will specifically show that the transfer processes are fast enough to ignore heat dissipation loss.
description: 17 pages, 6 figures
Analysis of Helicopter Flight Dynamics through Modeling and Simulation of Primary Flight Control Actuation System
Creators: name: Nelson, Hunter Barton
Publisher: name: Digital Repository at the University of Maryland
Year: 2015
Subjects: subject: Aerospace engineering
subject: Actuator
subject: Dynamics
subject: Flight Controls
subject: Helicopter

description: A simplified second-order transfer function actuator model used in most flight dynamics applications cannot easily capture the effects of different actuator parameters. The present work integrates a nonlinear actuator model into a nonlinear state space rotorcraft model to determine the effect of actuator parameters on key flight dynamics.

The completed actuator model was integrated with a swashplate kinematics where step responses were generated over a range of key hydraulic parameters.  The actuator-swashplate system was then introduced into a nonlinear state space rotorcraft simulation where flight dynamics quantities such as bandwidth and phase delay analyzed.

Frequency sweeps were simulated for unique actuator configurations using the coupled nonlinear actuator-rotorcraft system.  The software package CIFER was used for system identification and compared directly to the linearized models.  As the actuator became rate saturated, the effects on bandwidth and phase delay were apparent on the predicted handling qualities specifications.
RECURRENCE AND TIMING OF EXPOSURE TO MATERNAL DEPRESSION AND THE DEVELOPMENT OF DEPRESSIVE AND CONDUCT SYMPTOMS IN CHILDREN WITH AND WITHOUT ADHD
Creators: name: Wang, Christine
Publisher: name: Digital Repository at the University of Maryland
Year: 2015
Subjects: subject: Psychology
subject: FOS: Psychology
subject: adhd
subject: conduct
subject: depression
subject: maternal depression
subject: recurrence
subject: timing

description: The current study examined the longitudinal associations between recurrence and timing of exposure to maternal depression and the development of depressive and conduct symptoms in children with and without ADHD. Methods: 125 children with ADHD and 122 comparison children, ages 4-6, were followed over an 8-year period (until age 12-14). Results: Total recurrence of maternal depression was associated with youth depressive and conduct symptoms. Moreover, early adolescent exposure to maternal depression predicted youth depressive symptoms for all children. Exposure to maternal depression during preschool, childhood, and early adolescence each independently predicted youth conduct symptoms. Child ADHD status moderated the link between total recurrence of maternal depression and youth depressive symptoms and the link between preschool exposure and youth depressive symptoms. Child ADHD status did not moderate relations between total recurrence and timing of exposure to maternal depression and youth conduct symptoms.
Closed-Loop Fluid Resuscitation: In-Silico Study
Creators: name: Lucas, Jon
Publisher: name: Digital Repository at the University of Maryland
Year: 2015
Subjects: subject: Mechanical engineering
subject: FOS: Mechanical engineering
subject: blood volume dynamics
subject: closed-loop fluid resuscitation
subject: control-oriented blood volume

description: This thesis validates a control-oriented model of human circulatory dynamics associated with hemorrhage and fluid resuscitation, uses this model to design a series of closed-loop controllers for fluid resuscitation, and demonstrates the viability of these controllers by examining the performance of these controllers in an established model of human cardiovascular physiology. First, a recently developed control-oriented model of hemorrhage and fluid resuscitation was validated across diverse physiological conditions using an established model of human cardiovascular physiology, by employing a system identification procedure. Second, a series of closed-loop controllers were designed based on the nominal control-oriented model, including proportional control and proportional-derivative control based on the root locus analysis, as well as observer-based optimal state feedback control based on modern control theory. Third, the performance and robustness of the designed closed-loop controllers were validated using the established model of human cardiovascular physiology. The results suggested that model-based closed-loop control may be a viable alternative to today’s manual fluid infusion practices.
Design and Simulation of Sine-Gordon Lattice System
Creators: name: Zhang, Miao
Publisher: name: Digital Repository at the University of Maryland
Year: 2015
Subjects: subject: Electrical engineering
subject: sine-Gordon equation
subject: sin(x)-circuit
subject: soliton

description: The sine-Gordon equation is one of the nonlinear and integrable partial differential equations that can be solved exactly and has soliton solution. This equation was first introduced for Josephson junction propagation and has been applied to many other scientific fields.

Based on three discretized forms of the sine-Gordon equation, i.e. conventional discrete sine-Gordon equation, Orfanidis’s discrete sine-Gordon equation and sine-lattice equation, we create and simulate three sine-Gordon lattice systems. By taking the difference between the adjacent outputs as the transmitting soliton signal, it is shown that all three systems could propagate the bell-shaped signal constantly and the sine-lattice equation system gives the best results.

Due to the low-voltage, low-power feature, we choose the MOS translinear circuit that exploits bulk voltages under weak inversion to realize the sine function in the sine-Gordon lattice system and the complete circuit of the sine-Gordon cell is also created utilizing this MOS translinear sin(x) circuit.
Measuring the Mass of Missing Baryons in the Halo of Andromeda Galaxy with Gamma-Ray Observations
Creators: name: Zhang, Yi
name: Liu, Ruo-Yu
name: Li, Hui
name: Shao, Shi
name: Yan, Huirong
name: Wang, Xiang-Yu
name: Sun, Xiao-Na
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: One of the biggest mysteries in the modern cosmology and galaxy formation is the hideout of the "missing baryons". The leading theory of galaxy formation predicts that a huge amount of baryons resides around galaxies extending out to their virial radii in the form of diffuse and hot gas of $10^6-10^7\,$K, which is also known as the major component of the circumgalactic medium (CGM). Studies by various groups via different techniques, however, have not reached a consensus on the role of CGM in accounting for the missing baryons, with the estimated contribution ranging from a minor fraction to enclosing the baryon budget of the galaxy. In this work we attempt to measure the mass of missing baryons in CGM with a novel method based on the gamma-ray observations of the extended halo of the Andromeda Galaxy. Since cosmic-ray particles that are generated inside the galaxy will eventually escape to the CGM, they will produce gamma-ray emission via the proton-proton collision with CGM. Different from some traditional measurements which are sensitive only to gas in certain specific temperature range, the hadronic gamma-ray flux is sensitive to baryonic gases in all phases and does not rely on the metallicity in the halo. Our result suggests that the total baryon mass contained within the virial radius is less than $(1.4-5)\times 10^{10}M_\odot$ according to the gamma-ray intensity obtained with a model-dependent analysis. It implies that the CGM of Andromeda Galaxy may not account for more than $30\%$ of the missing baryons, but the result is subject to uncertainties from the gamma-ray intensity upper limit, diffusion coefficient of the CRs in the halo as well as the stellar mass and dark matter halo mass of the galaxy. This method will become more constraining provided better understandings on these issues and more sensitive gamma-ray telescopes in the future.
description: 7 pages, 5 figures, 1 table, accepted for publication in ApJ
First-principles calculations of a high-pressure synthesized compound PtC
Creators: name: Li, L. Y.
name: Yu, W.
name: Jin, C. Q.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: First-principles density-functional method is used to study the recently high-pressure synthesized compound PtC. It is confirmed by our calculations that the platinum carbide has a zinc-blende ground-state phase at zero pressure and the rock-salt structure is a high-pressure phase. The theoretical transition pressure from zinc-blende to rock-salt is determined to be 52GPa. Furthermore, our calculation shows the possibility that the experimentally synthesized PtC by Ono et al. under high pressure condition might undergo a transition from rock-salt structure to zinc-blende after the pressure quench to ambient condition.
description: A revised version
An algorithm for finding minimal generating sets of finite groups
Creators: name: Udomworarat, Tanakorn
name: Suksumran, Teerapong
Publisher: name: arXiv
Year: 2020
Subjects: subject: Group Theory (math.GR)
subject: FOS: Mathematics
subject: Primary 05C25, Secondary 20F05, 20D99

description: In this article, we study connections between components of the Cayley graph $\mathrm{Cay}(G,A)$, where $A$ is an arbitrary subset of a group $G$, and cosets of the subgroup of $G$ generated by $A$. In particular, we show how to construct generating sets of $G$ if $\mathrm{Cay}(G,A)$ has finitely many components. Furthermore, we provide an algorithm for finding minimal generating sets of finite groups using their Cayley graphs.
description: 12 pages
In Vitro Study of an Orange Oil Derived Alternative to Antibiotics in the Treatment of Bovine Mastitis
Creators: name: Federman, Cassandra Skye
Publisher: name: Digital Repository at the University of Maryland
Year: 2015
Subjects: subject: Microbiology
subject: FOS: Biological sciences
subject: Animal diseases
subject: Animal sciences
subject: cattle
subject: dairy
subject: mastitis
subject: orange oil
subject: Staphylococcus aureus

description: Bovine mastitis is a costly disease in the U.S. dairy industry.  Its major causative agent Staphylococcus aureus is often unresponsive to antibiotic therapy.  Our first study examined terpeneless, cold-pressed Valencia (CPV) orange oil as a possible alternative to antibiotic therapy in the treatment of S. aureus associated bovine mastitis.  Orange oil showed significant inhibition of S. aureus growth and invasion of bovine epithelial mammary cells, but only modest reductions in pre-formed biofilms, which contribute to persistence of S. aureus infections.  Our second study examined major components of terpeneless, CPV orange oil.  Of four major compounds tested, only citral and linalool had significant inhibitory effects on S. aureus growth.  In addition, they were capable of reducing pre-formed biofilms as well as association and invasion to bovine epithelial mammary cells.  Part of this inhibition was due to downregulation of virulence and biofilm genes.
"The other side of the picture": Social History, Popular Culture, and the Idea of the Sand Creek Massacre
Creators: name: Tanner, Kerry
Publisher: name: Digital Repository at the University of Maryland
Year: 2015
Subjects: subject: History
subject: Native American studies
subject: Film studies
subject: film
subject: massacre
subject: memory
subject: Sand Creek
subject: western

description: Competing schools of thought regarding American imperialism, American constructions of race, Native American experiences, and white settlers’ place within the American West can be seen in non-fiction and fictional accounts of the 1864 Sand Creek massacre in what is now eastern Colorado. Due to a range of factors including the emergence of social history methodology and Cold War politics, a shift in both American historiography and fictional representations of Native Americans and the West can be observed in certain scholarly works and Western films and novels during the period 1945-1970. Debates over the meaning of Sand Creek, often inspired by film representations, also reveal Coloradans’ and Americans’ attempts to reckon with shameful and embarrassing events of the past by contesting notions of race and imperialism presented by Western fiction.
Some Economic Implications of Minimum Pricing: The Case of Wine Grapes in Australia
Creators: name: O'Mara, L. Paul
name: O'Mara, L. Paul
Publisher: name: Unknown
Year: 1981
Subjects: Demand and Price Analysis

description: Minimum pricing arrangements for grapes taken up by wineries in Australia arc briefly reviewed. A partial equilibrium model is developed to illustrate the implications of such arrangements for income transfers and dead-weight losses in both the grape and wine markets. An attempt is made to incorporate the contingencies of the long lead times associated with grape production and the possible occurrence of monopsonistic behaviour by wineries. The analysis is theoretical, so that, while directed specifically at the wine grape industry in Australia, much of it is relevant to other instances of minimum pricing for agricultural commodities.
Bayesian analysis of the spin distribution of LIGO/Virgo black holes
Creators: name: Garcia-Bellido, Juan
name: Siles, Jose Francisco Nuño
name: Morales, Ester Ruiz
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Gravitational wave detection from binary black hole (BBH) inspirals has become routine thanks to the LIGO/Virgo interferometers. The nature of these back holes remains uncertain. We study here the spin distributions of LIGO/Virgo black holes from the first catalogue GWTC-1 and the first four published BBH events from run O3. We compute the Bayes evidence for several independent priors: flat, isotropic, spin-aligned and anti-aligned. We find strong evidence for low spins in all of the cases, and significant evidence for small isotropic spins versus any other distribution. When considered as a homogeneous population of black holes, these results give support to the idea that LIGO/Virgo BBH are primordial.
description: Minor changes. Version accepted in Physics of the Dark Universe
Biotechnology: Scientific Potential and Socioeconomic Implications for Agriculture
Creators: name: Longworth, John W.
name: Longworth, John W.
Publisher: name: Unknown
Year: 1987
Subjects: Research and Development/Tech Change/Emerging Technologies

description: While genetic engineering has caught public attention, the associated advances in both cell fusion and tissue and cell culture hold more immediate promise for improving agricultural productivity. The potential of these biotechnologies for manipulating micro-organisms, improving plant production systems, improving animal and insect systems, and for industrial tissue culture, is briefly reviewed. The coming Biorevolution in agriculture will have much greater socio-economic impact than the Green Revolution. The distribution of these effects, both within and between countries, will be greatly influenced by private property rights. Biotechnology is not going to be a "quick fix" for the world food problem. Indeed, unless governments can meet the socio-economic policy challenges ahead, the Biorevolution will exacerbate the current paradox of famine in the midst of surplus.
A comparison of lexical access in adults who do and do not stutter
Creators: name: Howell, Timothy Andrew
Publisher: name: Digital Repository at the University of Maryland
Year: 2015
Subjects: subject: Speech therapy
subject: lexicalization
subject: phoneme monitoring
subject: stutter

description: Previous work has postulated that a deficit in lexicalization may be an underlying cause of a stuttering disorder (Prins, Main, & Wampler, 1997; Wingate, 1988).  This study investigates the time course of lexicalization of nouns and verbs in adults who stutter.  A generalized phoneme monitoring (GPM) paradigm was used.  Both populations showed a significant effect of word class (verbs yielded slower and less accurate monitoring than nouns), as well as phoneme position (word medial/final phonemes yielded slower and less accurate monitoring than word initial phonemes).  Few significant differences were found between groups, although the experimental group showed poorer performance in all conditions, with the exception of null trials, where the experimental group actually out-performed the control group.  The trends provide some level of support for the notion that people who stutter have a deficit in lexicalization, although the effect is mitigated by the lack of significance.
Stationary phase corrections in the process of bosonization of multi-quark interactions
Creators: name: Osipov, Alexander A.
name: Hiller, Brigitte
name: Moreira, Joao
name: Blin, Alex H.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The functional integration over the auxiliary bosonic variables of cubic order related with the effective action of the Nambu -- Jona-Lasinio model with 't Hooft term has recently been obtained in the form of a loop expansion. Even numbers of loops contribute to the action, while odd numbers of loops are assigned to the measure. We consider the two-loop corrections and analyse their effect on the low-lying pseudoscalar and scalar mass spectra, quark condensates and weak decay constants. The results are compared to the leading order calculations and other approaches.
description: 22 pages, LaTeX, to appear in European Physics Journal C
Non-intrusive and semi-intrusive uncertainty quantification of a multiscale in-stent restenosis model
Creators: name: Ye, Dongwei
name: Nikishova, Anna
name: Veen, Lourens
name: Zun, Pavel
name: Hoekstra, Alfons G.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computation (stat.CO)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Uncertainty estimations are presented of the response of a multiscale in-stent restenosis model, as obtained by both non-intrusive and semi-intrusive uncertainty quantification. The in-stent restenosis model is a fully coupled multiscale simulation of post-stenting tissue growth, in which the most costly submodel is the blood flow simulation. Surrogate modeling for non-intrusive uncertainty quantification takes the whole model as a black-box and maps directly from the three uncertain inputs to the quantity of interest, the neointimal area. The corresponding uncertain estimates matched the results from quasi-Monte Carlo simulations well. In the semi-intrusive uncertainty quantification, the most expensive submodel is replaced with a surrogate model. We developed a surrogate model for the blood flow simulation by using a convolutional neural network. The semi-intrusive method with the new surrogate model offered efficient estimates of uncertainty and sensitivity while keeping relatively high accuracy. It outperformed the result obtained with earlier surrogate models. It also achieved the estimates comparable to the non-intrusive method with similar efficiency. Presented results on uncertainty propagation with non-intrusive and semi-intrusive metamodeling methods allow us to draw some conclusions on the advantages and limitations of these methods.
Soldered Bundle Background for the De Sitter Top
Creators: name: Armenta, J.
name: Nieto, J. A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We prove that the mathematical framework for the de Sitter top system is the de Sitter fiber bundle. In this context, the concept of soldering associated with a fiber bundle plays a central role. We comment on the possibility that our formalism may be of particular interest in different contexts including MacDowell-Mansouri theory, two time physics and oriented matroid theory.
description: 12 pages, Latex; some improvements introduced, reference added, typos corrected
Systematically Accelerated Convergence of Path Integrals
Creators: name: Bogojevic, Aleksandar
name: Balaz, Antun
name: Belic, Aleksandar
Publisher: name: arXiv
Year: 2005
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: We present a new analytical method that systematically improves the convergence of path integrals of a generic $N$-fold discretized theory. Using it we calculate the effective actions $S^{(p)}$ for $p\le 9$ which lead to the same continuum amplitudes as the starting action, but that converge to that continuum limit as $1/N^p$. We checked this derived speedup in convergence by performing Monte Carlo simulations on several different models.
description: 4 pages, 1 figure
Dynamic relaxation of magnetic clusters in a ferromagnetic (Ga,Mn)As epilayer
Creators: name: Hamaya, K.
name: Koike, T.
name: Taniyama, T.
name: Fujii, T.
name: Kitamoto, Y.
name: Yamazaki, Y.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: A new scenario of the mechanism of intriguing ferromagnetic properties in Mn-doped magnetic semiconductor (Ga,Mn)As is examined in detail. We find that magnetic features seen in zero-field cooled and field cooled magnetizations are not interpreted with a single domain model [Phys. Rev. Lett. 95, 217204 (2005)], and the magnetic relaxation, which is similar to that seen in magnetic particles and granular systems, is becoming significant at temperatures above the lower-temperature peak in the temperature dependence of ac susceptibility, supporting the cluster/matrix model reported in our previous work [Phys. Rev. Lett. 94, 147203 (2005)]. Cole-Cole analysis reveals that magnetic interactions between such (Ga,Mn)As clusters are significant at temperatures below the higher-temperature peak in the temperature dependent ac susceptibility. The magnetizations of these films disappear above the temperature showing the higher-temperature peak, which is generally referred to as the Curie temperature. However, we suggest that these combined results are evidence that the temperature is actually the blocking temperature of (Ga,Mn)As clusters with a relatively high hole concentration compared to the (Ga,Mn)As matrix.
description: 8 pages, 7 figures, to appear in Phys. Rev. B
D4.3 - Impact, Exploitation and Sustainability Final Report
Creators: name: Gangas, Pilar
name: Alvarez, Arturo
name: Lyne, Fiona
Publisher: name: Zenodo
Year: 2022

description: This document presents the EU4CHILD final community building results, recommendations based on them, together with the impact, sustainability and exploitation strategies, based on multimethod results from the consultation with stakeholders’ fieldwork implemented under EU4CHILD. The achieved goals and the next steps to be taken by UNICA4EU have been discussed with the leaders of UNICA4EU WP4 and some of the next steps that will be taken have been suggested.
description: This project has received funding from the European Union's Call for Pilot Projects and Preparatory Actions (PPPA) under Grant Agreement No 101018783
Lie-Admissible Invariant Origin of Irreversibility for Matter and Antimatter at the Classical and Operator Levels
Creators: name: Santilli, Ruggero Maria
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: It was generally believed throughout the 20-th century that irreversibility is a purely classical event without operator counterpart. However, a classical irreversible system cannot be consistently decomposed into a finite number of reversible quantum particles (and, vice versa), thus establishing that the origin of irreversibility is basically unknown at the dawn of the 21-th century. To resolve this problem, we adopt the historical an- alytic representation of irreversibility by Lagrange and Hamilton with external terms in their analytic equations; we show that, when properly written, the brackets of the time evolution characterize covering Lie-admissible algebras; we show that the for- malism has a fully consistent operator counterpart given by the Lie-admissible branch of hadronic mechanics; we identify catastrophic mathematical and physical inconsis- tencies when irreversible formulations are treated with the conventional mathematics used for reversible systems; and show that, when the dynamical equations are treated with a novel irreversible mathematics, Lie-admissible formulations are fully consistent because invariant at both the classical and operator level. The case of closed-isolated systems verifying conventional total conservation laws, yet possessing an irreversible structure, is treated via the Lie-isotopic subclass of Lie-admissible formulations. The analysis is conducted for both matter and antimatter at the classical and operator levels to prevent insidious inconskistenmcies occurring for the sole study of matter or, separately, antimatter, as known known for the problem of grand unificationsr.
description: 37 pagew
Approximate value-directed belief state monitoring for partially observable Markov decision processes
Creators: name: Poupart, Pascal
Publisher: name: University of British Columbia
Year: 2009

description: Partially observable Markov decision processes (POMDPs) provide a principled approach to planning under uncertainty. Unfortunately, several sources of intractability currently limit the application of POMDPs to simple problems. The following thesis is concerned with one source of intractability in particular, namely the belief state monitoring task. As an agent executes a plan, it must track the state of the world by updating its beliefs with respect to the current state. Then, based on its current beliefs, the agent can look up the next action to execute in its plan. In many situations, an agent may be required to decide in real-time which action to execute next. Thus, efficient algorithms to update the current belief state would be desirable. Unfortunately, exact belief state monitoring turns out to be very time consuming for many domains. This thesis introduces a value-directed framework to analyze and design approximation methods that speed up the monitoring task. The goal of approximate belief state monitoring is to trade monitoring accuracy for efficiency. Thus, this framework outlines a principled approach to quantify the impact of approximating belief states on the original plan. Since at any point in time, an action is executed based on the current belief state, it may be possible that a less desirable action ends up being executed as a result of the approximations used to infer the current belief state. The framework developped covers a wide range of approximation methods including projection schemes and density trees. First, several bounds on the loss in decision quality due to approximate belief state monitoring are derived. Then, given a class of approximation methods, a few search algorithms are proposed to seek a relatively good approximation scheme within the given class. These algorithms essentially try to minimize the bounds derived. Next, a vector space analysis is performed to gain some insights regarding which properties of approximation methods are likely to ensure a minimal impact on decision quality. Finally, faster algorithms (than the previous ones) are designed to search for approximation methods that exhibit such properties.
Cosmic D-strings as Axionic D-term Strings
Creators: name: Blanco-Pillado, Jose J.
name: Dvali, Gia
name: Redi, Michele
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this work we derive non-singular BPS string solutions from an action that captures the essential features of a D-brane-anti-D-brane system compactified to four dimensions. The model we consider is a supersymmetric abelian Higgs model with a D-term potential coupled to an axion-dilaton multiplet. The strings in question are axionic D-term strings which we identify with the D-strings of type II string theory. In this picture the Higgs field represents the open string tachyon of the D-Dbar pair and the axion is dual to a Ramond Ramond form. The crucial term allowing the existence of non-singular BPS strings is the Fayet-Iliopoulos term, which is related to the tensions of the D-string and of the parent branes. Despite the presence of the axion, the strings are BPS and carry finite energy, due to the fact that the space gets very slowly decompactified away from the core, screening the long range axion field (or equivalently the theory approaches an infinitely weak 4D coupling). Within our 4D effective action we also identify another class of BPS string solutions (s-strings) which have no ten dimensional analog, and can only exist after compactification.
description: 26 pages, 4 figures; v2 Refs. added; v3 minor changes, version to appear in PRD
de-Sitter vacua via consistent D-terms
Creators: name: Villadoro, Giovanni
name: Zwirner, Fabio
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We introduce a new mechanism for producing locally stable de-Sitter or Minkowski vacua, with spontaneously broken N=1 supersymmetry and no massless scalars, applicable to superstring and M-theory compactifications with fluxes. We illustrate the mechanism with a simple N=1 supergravity model that provides parametric control on the sign and the size of the vacuum energy. The crucial ingredient is a gauged U(1) that involves both an axionic shift and an R-symmetry, and severely constrains the F- and D-term contributions to the potential.
description: 4 pages, 1 figure, v3: published version
NMR Evidence of Antiferromagnetic Spin Fluctuations in Nd$_{0.85}$Sr$_{0.15}$NiO$_2$
Creators: name: Cui, Yi
name: Li, C.
name: Li, Q.
name: Zhu, Xiyu
name: Hu, Z.
name: Yang, Yi-feng
name: Zhang, J. S.
name: Yu, Rong
name: Wen, Hai-Hu
name: Yu, Weiqiang
Publisher: name: arXiv
Year: 2020
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Despite the recent discovery of superconductivity in Nd$_{1-x}$Sr$_{x}$NiO$_2$ thin films, the absence of superconductivity and antiferromagnetism in their bulk materials remain a puzzle. Here we report the $^{1}$H NMR measurements on powdered Nd$_{0.85}$Sr$_{0.15}$NiO$_2$ samples by taking advantage of the enriched proton concentration after hydrogen annealing. We find a large full width at half maximum of the spectrum, which keeps increasing with decreasing the temperature and exhibits an upturn behavior at low temperatures. The spin-lattice relaxation rate $1/^{1}T_1$ is strongly enhanced when lowering the temperature, developing a broad peak at about 40 K, then decreases following a spin-wave-like behavior $1/^{1}T_1{\sim}T^2$ at lower temperatures. These results evidence a short-range glassy antiferromagnetic ordering of magnetic moments below 40 K and dominant antiferromagnetic fluctuations extending to much higher temperatures. Our findings reveal the strong electron correlations in bulk Nd$_{0.85}$Sr$_{0.15}$NiO$_2$, and shed light on the mechanism of superconductivity observed in films of nickelates.
description: 6 pages, 4 figures
Grit and Engagement as Mediators of the Relation between Academic Support and Literacy Achievement in Ethnic Minority Elementary School Students
Creators: name: Atapattu, Ranga
Publisher: name: Digital Repository at the University of Maryland
Year: 2015
Subjects: subject: Education

description: The relation of academic support from teachers and peers with later literacy achievement in ethnic minority elementary school students is not well defined in previous literature. Earlier theoretical models suggest that other socioemotional constructs, such as engagement and motivation, may act as mediators in this link. In this study, the model is updated with grit, a new motivational construct that has been tied to positive academic outcomes. This study uses a multi-method, longitudinal design (N = 144; ethnic minority 3rd-5th grade students) and mediation analyses to investigate four models where the link between academic support (from teachers or peers) and academic achievement is mediated by either engagement or grit. While earlier studies suggested that teacher academic support is positively correlated with academic achievement among students, this study did not find that correlation. However, both grit and emotional engagement acted as significant mediators between peer academic support and literacy achievement.
Superconducting fluctuations in overdoped Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$
Creators: name: He, Yu
name: Chen, Su-Di
name: Li, Zi-Xiang
name: Zhao, Dan
name: Song, Dongjoon
name: Yoshida, Yoshiyuki
name: Eisaki, Hiroshi
name: Wu, Tao
name: Chen, Xian-Hui
name: Lu, Dong-Hui
name: Meingast, Christoph
name: Devereaux, Thomas P.
name: Birgeneau, Robert J.
name: Hashimoto, Makoto
name: Lee, Dung-Hai
name: Shen, Zhi-Xun
Publisher: name: arXiv
Year: 2020
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Fluctuating superconductivity - vestigial Cooper pairing in the resistive state of a material - is usually associated with low dimensionality, strong disorder or low carrier density. Here, we report single particle spectroscopic, thermodynamic and magnetic evidence for persistent superconducting fluctuations in heavily hole-doped cuprate superconductor Bi$_2$Sr$_2$CaCu$_2$O$_{8+δ}$ ($T_c$ = 66~K) despite the high carrier density. With a sign-problem free quantum Monte Carlo calculation, we show how a partially flat band at ($π$,0) can help enhance superconducting phase fluctuations. Finally, we discuss the implications of an anisotropic band structure on the phase-coherence-limited superconductivity in overdoped cuprates and other superconductors.
description: main: 8 pages, 6 figures + supplement: 10 pages, 15 figures
Energy of interaction between solid surfaces and liquids
Creators: name: Gouin, Henri
Publisher: name: arXiv
Year: 2008
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We consider the wetting transition on a planar surface in contact with a semi-infinite fluid. In the classical approach, the surface is assumed to be solid, and when interaction between solid and fluid is sufficiently short-range, the contribution of the fluid can be represented by a surface free energy with a density of the form Phi(rho_s), where rho_s is the limiting density of the fluid at the surface. In the present paper we propose a more precise representation of the surface energy that takes into account not only the value of rho_s but also the contribution from the whole density profile rho(z) of the fluid, where z is the coordinate normal to the surface. The specific value of the functional of rho_s at the surface is expressed in mean-field approximation through the potentials of intermolecular interaction and some other parameters of the fluid and the solid wall. An extension to the case of fluid mixtures in contact with a solid surface is proposed.
description: 16 pages
THE IMPACT OF CLIMATE CHANGE ON AGRICULTURAL CRITICAL SOURCE AREAS (CSAS) AND BEST MANAGEMENT PRACTICES (BMPS) IN EASTERN MARYLAND
Creators: name: Renkenberger, Jaison
Publisher: name: Digital Repository at the University of Maryland
Year: 2015
Subjects: subject: Environmental engineering
subject: FOS: Environmental engineering
subject: Water resources management
subject: Climate change
subject: Climate Change
subject: Critical Source Areas
subject: NPS pollution
subject: SWAT Model
subject: Water Quality
subject: Watershed Modeling

description: Chesapeake Bay jurisdictions are required to develop Watershed Implementation Plans (WIPs) to reduce Non-Point Source (NPS) pollution by sediment, nitrogen, and phosphorus, and meet EPA Total Maximum Daily Loads (TMDLs) for water quality. This study quantifies the potential impacts of climate change on Critical Source Areas (CSAs) and Best Management Practice (BMP) efficiencies, two keys to WIP success, in an agricultural watershed in Maryland. The SWAT model was calibrated for the watershed and subjected to climate scenarios SRES B1, A1B and A2, over mid- and end-century time horizons. Simulation results predict that changed precipitation patterns will produce at least a doubling of CSA areas within the watershed and that, with BMPs designed for current climate, TMDLs will be exceeded by a factor of up to 2.4. For WIPs to be robust against climate change, BMPs must be designed for future climate and community-based, participatory implementation strategies are needed.
Influence of turbulence on the dynamo threshold
Creators: name: Laval, Jean-Philippe
name: Blaineau, Pierre
name: Leprovost, Nicolas
name: Dubrulle, Bérengère
name: Daviaud, François
Publisher: name: arXiv
Year: 2006
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Astrophysics (astro-ph)
subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: We use direct and stochastic numerical simulations of the magnetohydrodynamic equations to explore the influence of turbulence on the dynamo threshold. In the spirit of the Kraichnan-Kazantsev model, we model the turbulence by a noise, with given amplitude, injection scale and correlation time. The addition of a stochastic noise to the mean velocity significantly alters the dynamo threshold. When the noise is at small (resp. large) scale, the dynamo threshold is decreased (resp. increased). For a large scale noise, a finite correlation time reinforces this effect.
HOW TO PAY FOR AGRICULTURAL INCOME SUPPORTS
Creators: name: Runge, C. Ford
name: Runge, C. Ford
Publisher: name: Unknown
Year: 1986
Subjects: Agricultural and Food Policy
Agricultural Finance

description: This paper examines the impact of deficit reductions on agricultural price support spending, and proposes several policy innovations designed to remove agricultural programs from the entitlement category. First, agricultural program costs are analyzed in relation to deficit reduction requirements resulting from recent legislation. Second, price support and food stamp programs are proposed as a separate budget category to be financed through an excise tax on retail food sales. Third, the incidence of this tax on consumers is considered, and compensation for lower income groups is proposed via expanded eligibility for the food stamp program. A final section presents some conclusions for policy.
Generation and storage of spin squeezing via learning-assisted optimal control
Creators: name: Tan, Qing-Shou
name: Zhang, Mao
name: Chen, Yu
name: Liao, Jie-Qiao
name: Liu, Jing
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The generation and storage of spin squeezing is an attracting topic in quantum metrology and the foundations of quantum mechanics. The major models to realize the spin squeezing are the one- and two-axis twisting models. Here, we consider a collective spin system coupled to a bosonic field, and show that proper constant-value controls in this model can simulate the dynamical behaviors of these two models. More interestingly, a better performance of squeezing can be obtained when the control is time-varying, which is generated via a reinforcement learning algorithm. However, this advantage becomes limited if the collective noise is involved. To deal with it, we propose a four-step strategy for the construction of a new type of combined controls, which include both constant-value and time-varying controls, but performed at different time intervals. Compared to the full time-varying controls, the combined controls not only give a comparable minimum value of the squeezing parameter over time, but also provides a better lifetime and larger full amount of squeezing. Moreover, the amplitude form of a combined control is simpler and more stable than the full time-varying control. Therefore, our scheme is very promising to be applied in practice to improve the generation and storage performance of squeezing.
description: 10 pages, 6 figures, close to published version