1,699 research outputs found
A Sensitive Faraday Rotation Setup Using Triple Modulation
The utilization of polarized targets in scattering experiments has become a
common practice in many major accelerator laboratories. Noble gases are
especially suitable for such applications, since they can be easily
hyper-polarized using spin exchange or metastable pumping techniques. Polarized
helium-3 is a very popular target because it often serves as an effective
polarized neutron due to its simple nuclear structure. A favorite cell material
to generate and store polarized helium-3 is GE-180, a relatively dense
aluminosilicate glass. In this paper, we present a Faraday rotation method,
using a new triple modulation technique, where the measurement of the Verdet
constants of SF57 flint glass, pyrex glass, and air were tested. The
sensitivity obtained shows that this technique may be implemented in future
cell wall characterization and thickness measurements. We also discuss the
first ever extraction of the Verdet constant of GE-180 glass for four
wavelength values of 632 nm, 773 nm, 1500 nm, and 1547 nm, whereupon the
expected 1/{\lambda}^{2} dependence was observed.Comment: 4 pages, 2 figures Updated version for RSI submissio
The Role of Home Country Political Resources for Brazilian Multinational Companies
This paper aims to analyze the interactions between home country governments and Developing Country Multinational Companies (DMNCs). Drawing on evidence from the Brazilian political environment and Brazilian multinationals we investigate the mechanisms governments use to influence the internationalization process of domestic companies and firms’ political strategic responses to shape the political institutional environment in which they operate. We argue that foreign direct investment (FDI) outflows from developing economies need to be explored given specific country level contextual factors, such as high levels of government involvement. Our main findings support this idea and indicate that home country governments use a series of formal and informal mechanisms in order to drive the international expansion of DMNCs in both the entry and consolidation phases. Moreover, DMNCs political behavior in the home country political environment accounts for an important part of their strategy to develop political resources and obtain above average returns from governmental benefits
Study of Cell Charging Effects for the Neutron Electric Dipole Moment Experiment at Oak Ridge National Laboratory
The neutron electric dipole moment (nEDM) collaboration at the Spallation Neutron Source plans to use ultra-cold neutrons in superfluid helium to improve the nEDM limit by about two orders of magnitude. In this apparatus, neutrons are stored in poly(methyl methacrylate), PMMA, cells located in a strong, stable electric field. This electric field is produced by high voltage electrodes located outside of the neutron cells. Several sources generate charged particles inside the neutron cells. The electric field pulls these charges farther apart, attracting each to the oppositely charged electrode. As the charges build up on the cells walls, they create an increasing electric field in opposition to the field of the electrodes, reducing the strength and stability of the net field. The field fluctuations need to be kept below 1% in order to achieve the desired sensitivity, making it necessary to study this cell charging behavior, determine its effect on the experiment, and find ways to neutralize the charge.
A compact test setup was designed to study this effect using a scaled down cell and electrodes. Charged particles are generated by ionizing the helium with a 137Cs source and the electric field is monitored via the electro-optic Kerr effect. Linearly polarized light is passed through the helium. The Kerr effect then introduces an ellipticity to the polarization that is proportional to the square of the electric field. This effect is small compared to background noise; a triple modulation technique was used and adapted to measure the induced ellipticities. Liquid nitrogen was used to test the performance of the system. Having a Kerr constant that is over a factor of 100 larger than the helium Kerr constant, it is an ideal candidate for calibrating the polarimetry. Cell charging data was taken in liquid nitrogen as part of the system calibration and as a proof of principle. This document reports the results from the cell charging data taken in liquid nitrogen as well as the data taken in liquid helium
“Gut Heil”: Dayton Turner’s Preservation during the First World War
Good greetings, or Gut Heil!, was a common greeting made by German-Americans in Dayton. These German-Americans and the lives of millions of Americans on April the sixth, 1917 were forever altered because of the United States’ decision to join the war effort. As the United States entered the First World War, domestically the population felt emboldened to aid in the war effort in every way possible. The First World War brought unprecedented hysteria towards German-Americans for fear of treason and espionage upon the war effort. Eventually even legislation was passed 1 to halt anyone in the United States from interfering with the American war effort. With the true war happening thousands of miles from the United States, the war front for many citizens was actually the home front.2 In an effort to support the war effort and to create a unified patriotic nation, many Americans turned to their fellow citizens and began to question their loyalty that culminated in an anti-German hysteria. This hysteria was unprecedented from anything ever experienced within the United States. Radical displays of hysteria began to occur throughout the nation, including book burnings throughout the United States, including in Ohio, the lynching of Robert Prager, beatings, adoption of laws that restrict German language and immense pressure to abandon cultural practices associated with Germany or German-Americans
Development and pilot evaluation of a personalized decision support intervention for low risk prostate cancer patients.
ObjectivesDevelopment and pilot evaluation of a personalized decision support intervention to help men with early-stage prostate cancer choose among active surveillance, surgery, and radiation.MethodsWe developed a decision aid featuring long-term survival and side effects data, based on focus group input and stakeholder endorsement. We trained premedical students to administer the intervention to newly diagnosed men with low-risk prostate cancer seen at the University of California, San Francisco. Before the intervention, and after the consultation with a urologist, we administered the Decision Quality Instrument for Prostate Cancer (DQI-PC). We hypothesized increases in two knowledge items from the DQI-PC: How many men diagnosed with early-stage prostate cancer will eventually die of prostate cancer? How much would waiting 3 months to make a treatment decision affect chances of survival? Correct answers were: "Most will die of something else" and "A little or not at all."ResultsThe development phase involved 6 patients, 1 family member, 2 physicians, and 5 other health care providers. In our pilot test, 57 men consented, and 44 received the decision support intervention and completed knowledge surveys at both timepoints. Regarding the two knowledge items of interest, before the intervention, 35/56 (63%) answered both correctly, compared to 36/44 (82%) after the medical consultation (P = .04 by chi-square test).ConclusionsThe intervention was associated with increased patient knowledge. Data from this pilot have guided the development of a larger scale randomized clinical trial to improve decision quality in men with prostate cancer being treated in community settings
Event-triggered control for piecewise affine discrete-time systems
In the present work, we study the problems of stability analysis of piecewise-affine (PWA) discrete-time systems, and trigger-function design for discrete-time event-triggered control systems. We propose a representation for piecewise-affine systems in terms of ramp functions, and we rely on Lyapunov theory for the stability analysis. The proposed implicit piecewise-affine representation prevents the shortcomings of the existing stability analysis approaches of PWA systems. Namely, the need to enumerate regions and allowed transitions of the explicit representations. In this context, we can emphasize two benefits of the proposed approach: first, it makes possible the analysis of uncertainty in the partition and, thus, the transitions. Secondly, it enables the analysis of event-triggered control systems for the class of PWA systems since, for ETC, the transitions cannot be determined as a function of the state variables. The proposed representation, on the other hand, implicitly encodes the partition and the transitions. The stability analysis is performed with Lyapunov theory techniques. We then present conditions for exponential stability. Thanks to the implicit representation, the use of piecewise quadratic Lyapunov functions candidates becomes simple. These conditions can be solved numerically using a linear matrix inequality formulation. The numerical analysis exploits quadratic expressions that describe ramp functions to verify the positiveness of extended quadratic forms. For ETC, a piecewise quadratic trigger function defines the event generator. We find suitable parameters for the trigger function with an optimization procedure. As a result, this function uses the information on the partition to reduce the number of events, achieving better results than the standard quadratic trigger functions found in the literature. We provide numerical examples to illustrate the application of the proposed representation and methods.Ce manuscrit présente des résultats sur l’analyse de stabilité des systèmes affines par morceaux en temps discret et sur le projet de fonctions de déclenchement pour des stratégies de commande par événements. Nous proposons une représentation pour des systèmes affines par morceaux et l’on utilise la théorie de stabilité de Lyapunov pour effectuer l’analyse de stabilité globale de l’origine. La nouvelle représentation implicite que nous proposons rend plus simple l’analyse de stabilité car elle évite l’énumération des régions et des transitions entre régions tel que c’est fait dans le cas des représentations explicites. Dans ce contexte nous pouvons souligner deux avantages principaux, à savoir I) la possibilité de traiter des incertitudes dans la partition qui définit le système et, par conséquent des incertitudes dans les transitions, II) l’analyse des stratégies de commande par événements pour des systèmes affines par morceaux. En effet, dans ces stratégies les transitions ne peuvent pas être définies comme des fonctions des variables d’état. La théorie de stabilité de Lyapunov est utilisée pour établir des conditions pour la stabilité exponentielle de l’origine. Grâce à la représentation implicite des partitions nous utilisons des fonctions de Lyapunov quadratique par morceaux. Ces conditions sont données par des inégalités dont la solution numérique est possible avec une formulation par des inégalités matricielles linéaires. Ces formulations numériques se basent sur des expressions quadratiques décrivant des fonctions rampe. Pour des stratégies par événement, une fonctions quadratique par morceaux est utilisée pour le générateur d’événements. Nous calculons les paramètres de ces fonctions de déclenchement a partir de solutions de problèmes d’optimisation. Cette fonction de déclenchement quadratique par morceaux permet de réduire le nombre de d’événementsen comparaison avec les fonctions quadratiques utilisées dans la littérature. Nous utilisons des exemples numériques pour illustrer les méthodes proposées.No presente trabalho, são estudados os problemas de análise de estabilidade de sistemas afins por partes e o projeto da função de disparo para sistemas de controle baseado em eventos em tempo discreto. É proposta uma representação para sistemas afins por partes em termos de funções rampa, e é utilizada a teoria de Lyapunov para a análise de estabilidade. A representação afim por partes implícita proposta evita algumas das deficiências das abordagens de análise de estabilidade de sistemas afins por partes existentes. Em particular, a necessidade de anumerar regiões e transições admissíveis das representações explícitas. Neste contexto, dois benefícios da abordagem proposta podem ser enfatizados: primeiro, ela torna possível a análise de incertezas na partição, e, assim, nas transições. Segundo, ela permite a análise de sistemas de controle baseado em eventos para a classe de sistemas afins por partes, já que, para o controle baseado em eventos, as transições não podem ser determinadas como uma função das variáveis de estado. A representação proposta, por outro lado, codifica implicitamente a partição e as transições. A análise de estabilidade é realizada com técnicas da teoria de Lyapunov. Condi- ções para a estabilidade exponencial são então apresentadas. Graças à representação implícita, o uso de funções candidatas de Lyapunov se torna simples. Essas condições podem ser resolvidas numéricamente usando uma formulação de desigualdades matriciais lineares. A análise numérica explora expressões quadráticas que descrevem funções de rampa para verificar a postivividade de formas quadráticas extendidas. Para o controle baseado em eventos, uma função de disparo quadrática por partes define o gerador de eventos. Parâmetros adequados para a função de disparo sãoencontrados com um procedimento de otimização. Como resultado, esta função usa informação da partição para reduzir o número de eventos, obtendo resultados melhores do que as funções de disparo quadráticas encontradas na literatura. Exemplos numéricos são fornecidos para ilustrar a aplicação da representação e mé- todos propostos
Using Grit and Growth Mindset to Foster Resilience and Professionalism in Law Students and Attorneys
The presentation introduced current research showing correlation between grit, growth mindset, and success in varied disciplines, then suggested several means for improving grit. Attendees discussed several problems that a young lawyer might experience and considered how grit and growth mindset might affect the lawyer\u27s response to the problem
The characterization of wing-wing vortex interactions of a tandem flapping wing configuration and its relationship to the phase angle and wing spacing.
A number of flying insects make use of tandem wing configurations, suggesting that such a setup may have potential advantages over a single wing at low Reynolds numbers. Dragonflies, which are fast and highly maneuverable, demonstrate well, the potential performance of such a configuration. In a tandem wing configuration, the hindwing often operates in the wake of the forewing and, hence, its performance is affected by the vortices shed by the forewing. Changes in the phase angle between the flapping motions of the fore and hind wings, as well as the spacing between them, can affect the resulting vortex/wing and vortex/vortex interactions. In this thesis flapping wings in a tandem configuration were simulated using an incompressible Navier-Stokes solver on composite overlapping grids. Harmonic single frequency sinusoidal oscillations consisting of combined pitch and plunge motions were used for the flapping wing kinematics at a Strouhal number of 0.3. Different wing spacings ranging from 0.1 chords to 1 chord were tested at three different phase angles, 0°, 90° and 180°. It was found that changes in the spacing and phase angle affected the timing of the interaction between the vortex shed from the forewing and the hindwing. Such an interaction affects the LEV formation on the hindwing and results in changes to the aerodynamic force production and efficiencies of the hindwing. It is also observed that changing the phase angle has a similar effect as changing the spacing. The results further show that at different spacings the peak force generation occurs at different phase angles, as do the peak efficiencies. The aerodynamics of the hindwing was also compared in detail to a single wing, with the same geometry and undergoing the same flapping kinematics, to determine the effect of vortex shedding from the forewing on the hindwing, as well as how the phase angle affects the interaction. The average lift, thrust and power coefficients and the average efficiency of the fore and hind wings were compared to a single wing to determine how the tandem wing interaction affects performance
Anticipating Industry Convergence in the Context of Industry 4.0
© 2018 Portland International Conference on Management of Engineering and Technology, Inc. (PICMET). The merger of the digital and physical world in the context of Industry 4.0 is about to disrupt value chains and markets in almost every industry sector. In this context, the Internet of Things (IoT), enabling linkages and communication between physical and virtual objects, is the technological foundation of implementing Industry 4.0. In such a fast-paced environment, it is vital for companies to react quickly and exploit new business opportunities. One critical example is the interplay between logistics and information and communications technology (ICT) industries, where IoT has the potential to align goods and information flows in an unprecedented manner. The arising new functionalities, services and products show potential to blur the industries' boundaries and give birth to a whole new industry segment. Therefore, the present study strives to anticipate industry convergence between logistics and ICT industries in the realm of IoT. The empirical patent analysis is based on IPC co-classification and assignee structure. The analyses are refined along the different levels of IoT to provide detailed insights for companies where new technological and market competences need to be acquired
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