257 research outputs found
Imaging electric fields in the vicinity of cryogenic surfaces using Rydberg atoms
The ability to characterize static and time-dependent electric fields in situ
is an important prerequisite for quantum-optics experiments with atoms close to
surfaces. Especially in experiments which aim at coupling Rydberg atoms to the
near field of superconducting circuits, the identification and subsequent
elimination of sources of stray fields is crucial. We present a technique that
allows the determination of stray-electric-field distributions
at distances of less than from (cryogenic) surfaces using
coherent Rydberg-Stark spectroscopy in a pulsed supersonic beam of metastable
helium atoms. We demonstrate the
capabilities of this technique by characterizing the electric stray field
emanating from a structured superconducting surface. Exploiting coherent
population transfer with microwave radiation from a coplanar waveguide, the
same technique allows the characterization of the microwave-field distribution
above the surface.Comment: 6 pages, 4 figure
Driving Rydberg-Rydberg transitions from a co-planar microwave waveguide
The coherent interaction between ensembles of helium Rydberg atoms and
microwave fields in the vicinity of a solid-state co-planar waveguide is
reported. Rydberg-Rydberg transitions, at frequencies between 25 GHz and 38
GHz, have been studied for states with principal quantum numbers in the range
30 - 35 by selective electric-field ionization. An experimental apparatus
cooled to 100 K was used to reduce effects of blackbody radiation.
Inhomogeneous, stray electric fields emanating from the surface of the
waveguide have been characterized in frequency- and time-resolved measurements
and coherence times of the Rydberg atoms on the order of 250 ns have been
determined.Comment: 5 pages, 5 figure
Vacuum-ultraviolet frequency-modulation spectroscopy
Frequency-modulation (FM) spectroscopy has been extended to the
vacuum-ultraviolet (VUV) range of the electromagnetic spectrum. Coherent VUV
laser radiation is produced by resonance-enhanced sum-frequency mixing
() in Kr and Xe using two
near-Fourier-transform-limited laser pulses of frequencies
and . Sidebands generated in the output of the second laser ()
using an electro-optical modulator operating at the frequency
are directly transfered to the VUV and used to record FM
spectra. Demodulation is demonstrated both at and
. The main advantages of the method are that its
sensitivity is not reduced by pulse-to-pulse fluctuations of the VUV laser
intensity, compared to VUV absorption spectroscopy is its background-free
nature, the fact that its implementation using table-top laser equipment is
straightforward and that it can be used to record VUV absorption spectra of
cold samples in skimmed supersonic beams simultaneously with
laser-induced-fluorescence and photoionization spectra. To illustrate these
advantages we present VUV FM spectra of Ar, Kr, and N in selected regions
between 105000cm and 122000cm.Comment: 23 pages, 10 figure
Measuring the dispersive frequency shift of a rectangular microwave cavity induced by an ensemble of Rydberg atoms
In recent years the interest in studying interactions of Rydberg atoms or
ensembles thereof with optical and microwave frequency fields has steadily
increased, both in the context of basic research and for potential applications
in quantum information processing. We present measurements of the dispersive
interaction between an ensemble of helium atoms in the 37s Rydberg state and a
single resonator mode by extracting the amplitude and phase change of a weak
microwave probe tone transmitted through the cavity. The results are in
quantitative agreement with predictions made on the basis of the dispersive
Tavis-Cummings Hamiltonian. We study this system with the goal of realizing a
hybrid between superconducting circuits and Rydberg atoms. We measure maximal
collective coupling strengths of 1 MHz, corresponding to 3*10^3 Rydberg atoms
coupled to the cavity. As expected, the dispersive shift is found to be
inversely proportional to the atom-cavity detuning and proportional to the
number of Rydberg atoms. This possibility of measuring the number of Rydberg
atoms in a nondestructive manner is relevant for quantitatively evaluating
scattering cross sections in experiments with Rydberg atoms
Dissociation energy of the hydrogen molecule at 10 accuracy
The ionization energy of ortho-H has been determined to be
cm
from measurements of the GK(1,1)--X(0,1) interval by Doppler-free two-photon
spectroscopy using a narrow band 179-nm laser source and the ionization energy
of the GK(1,1) state by continuous-wave near-infrared laser spectroscopy.
(H) was used to derive the dissociation energy of
H, (H), at cm with a
precision that is more than one order of magnitude better than all previous
results. The new result challenges calculations of this quantity and represents
a benchmark value for future relativistic and QED calculations of molecular
energies.Comment: 6 pages, 5 figure
RelatĂłrio sobre experiĂȘncias na implantação de unidades de referencia tecnolĂłgica em sistemas agroflorestais, no Projeto IguatĂș II.
O pĂșblico alvo preferencial desta publicação sĂŁo os agricultores familiares e tĂ©cnicos de campo, principalmente aqueles motivados pelo cultivo de espĂ©cies arbĂłreas nativas e interessados na adoção de prĂĄticas agroecolĂłgicas. Com conteĂșdo simples e de fĂĄcil leitura, as informaçÔes e discussĂ”es foram descritas com a intenção de subsidiar a introdução do componente florestal nos sistemas de produção agropecuĂĄrios, visando principalmente Ă sustentabilidade e Ă qualidade ambiental. A diversificação dos eventos ocorridos nas diferentes experiĂȘncias traduz importantes recomendaçÔes que, embora de carĂĄter aparentemente simples, nem sempre sĂŁo de fĂĄcil solução.bitstream/item/40275/1/Doc181.pd
Chronic hand eczema in Europe:Patient experiences and perspectives (CHEPEP) in qualitative interviews
Background: Chronic hand eczema (CHE) is a very common skin disease among the European population. It causes itch and pain and, in more severe cases, seriously impairs hand functioning at work and in private life. Objectives: To explore perspectives of people with lived experience on CHE-related problems, wishes and goals. Methods: Following a qualitative approach, we conducted topic-guided interviews in five European countries and applied template analysis to identify recurrent themes among patients with CHE. Results: We interviewed 60 patients in seven outpatient dermatological and occupational medicine clinics in Croatia, Denmark, Germany, the Netherlands and Spain. Five main themes were identified: (1) knowledge about the disease and its course, (2) preventive behaviour, (3) hand eczema therapy, (4) impact on everyday life and (5) attitudes towards CHE and healthcare. Participants did not feel well informed about CHE, especially about causes, triggers and treatment options. Preventive measures were experienced as more or less effective but also cumbersome. Experiences with therapy were diverse. Treatment satisfaction depended on the results and on the perceived support from the treatment teams. Participants found it important to be taken seriously, to receive practical advice, to try out additional treatments or examinations, find new hope and have occupational perspectives. They wished that others could better understand the physical and emotional burden of CHE. Patient support groups were not mentioned. Participants found it important to learn to take care of themselves and accept life with CHE. Conclusions: Due to its annoying symptoms, high visibility and impaired functioning at work and in private life, CHE has a high emotional and social impact. Some people may require support to learn coping with CHE and its prevention. Patients wish for information about causes and triggers. They value physicians who listen to them and keep looking for solutions.</p
PrĂĄticas de marketing educacional nas escolas pĂșblicas
O presente trabalho tem como objetivo identificar prĂĄticas de Marketing Educacional nas escolas pĂșblicas.
Tendo por base razĂ”es pessoais, profissionais, teĂłricas e legais que justificam estudos sobre as prĂĄticas de Marketing Educacional nas escolas pĂșblicas, revĂȘ-se a literatura sobre a evolução do marketing (geral) atĂ© Ă emergĂȘncia do marketing societal e do Marketing Educacional.
Partindo dos normativos legais e da literatura, exploram-se as fontes de informação, a autonomia das escolas, a accountability, o planeamento estratĂ©gico e evidĂȘncias dessas prĂĄticas associadas ao Marketing Educacional. Para o efeito, optou-se, metodologicamente, por realizar uma pesquisa quantitativa atravĂ©s de um inquĂ©rito por questionĂĄrio realizado junto dos(as) diretores(as) dos agrupamentos de escolas e escolas nĂŁo agrupadas de Portugal Continental.
No que respeita aos principais resultados obtidos, Ă© possĂvel concluir que, apesar de haver evidĂȘncias de predominar a orientação da gestĂŁo para a âproduçãoâ do serviço educativo, hĂĄ prĂĄticas de Marketing Educacional nas escolas pĂșblicas. Contudo, as escolas tĂȘm ainda uma consciĂȘncia mĂope do que Ă© o Marketing Educacional, pois hĂĄ dĂ©fice na identificação e na implementação dessas prĂĄticas. Verifica-se que as escolas fazem estudos de suporte a decisĂ”es sobre oferta formativa, de avaliação institucional e de satisfação junto dos alunos e restante comunidade educativa. Definem e implementam estratĂ©gias nĂŁo sĂł para cumprir os normativos legais, mas tambĂ©m adequar os serviços aos alunos, tornando-os parte ativa da coprodução do serviço educativo.
Com base nas conclusÔes e nas opçÔes de concordùncia do(a)s diretores(as), foi delineado um plano de ação de intervenção de Marketing Educacional.This project aims to identify educational marketing practices in state schools.
Based on personal, professional, theoretical and legal reasons that justify studies on Educational Marketing practices in state schools, we'll be reviewing the literature on the evolution of marketing, and of general marketing until the emergence of Educational Marketing.
Starting from legal requirements and literature, we will explore information sources, school autonomy, accountability, strategic and practical evidence associated with Educational Marketing. For this purpose, it was decided, as far as methodology is concerned, to carry out a quantitative research through a survey with the School Directors/headmasters of the school groupings and schools in mainland Portugal.
Concerning the main results obtained, it is possible to conclude that, although there is evidence of a predominant management orientation towards the âproductionâ of the educational service, it is undeniable that there are Educational Marketing practices in state schools. However, schools still have a short-sighted awareness of what Educational Marketing is, as there is a deficit in identifying and implementing these practices. In fact, schools carry out surveys that support decisions on training courses, institutional assessment and satisfaction among students and the rest of the educational community. They define and implement strategies not only to comply with legal regulations, but also to adapt services to students, making them an active part of the co-production of the educational service.
Based on the headmasters' conclusions and agreement options, an Educational Marketing action plan was outlined.
KEYWORDS: Educational Marketing
The relevance of model-driven engineering thirty years from now
International audienceAlthough model-driven engineering (MDE) is now an established approach for developing complex software systems, it has not been universally adopted by the software industry. In order to better understand the reasons for this, as well as to identify future opportunities for MDE, we carried out a week-long design thinking experiment with 15 MDE experts. Participants were facilitated to identify the biggest problems with current MDE technologies, to identify grand challenges for society in the near future, and to identify ways that MDE could help to address these challenges. The outcome is a reflection of the current strengths of MDE, an outlook of the most pressing challenges for society at large over the next three decades, and an analysis of key future MDE research opportunities
Systemic treatment of children and adolescents with atopic dermatitis aged â„2 years : a Delphi consensus project mapping expert opinion in Northern Europe
Publisher Copyright: © 2022 The Authors. Journal of the European Academy of Dermatology and Venereology published by John Wiley & Sons Ltd on behalf of European Academy of Dermatology and Venereology.Background: Paediatric atopic dermatitis (AD) can be burdensome, affecting mental health and impairing quality of life for children and caregivers. Comprehensive guidelines exist for managing paediatric AD, but practical guidance on using systemic therapy is limited, particularly for new therapies including biologics and Janus kinase (JAK) inhibitors, recently approved for various ages in this indication. Objectives: This expert consensus aimed to provide practical recommendations within this advancing field to enhance clinical decision-making on the use of these and other systemics for children and adolescents aged â„2 years with moderate-to-severe AD. Methods: Nineteen physicians from Northern Europe were selected for their expertise in managing childhood AD. Using a two-round Delphi process, they reached full or partial consensus on 37 statements. Results: Systemic therapy is recommended for children aged â„2 years with a clear clinical diagnosis of severe AD and persistent disease uncontrolled after optimizing non-systemic therapy. Systemic therapy should achieve long-term disease control and reduce short-term interventions. Recommended are cyclosporine A for short-term use (all ages) and dupilumab or methotrexate for long-term use (ages â„6 years). Consensus was not reached on the best long-term systemics for children aged 2â6 years, although new systemic therapies will likely become favourable: New biologics and JAK inhibitors will soon be approved for this age group, and more trial and real-world data will become available. Conclusions: This article makes practical recommendations on the use of systemic AD treatments for children and adolescents, to supplement international and regional guidelines. It considers the systemic medication that was available for children and adolescents with moderate-to-severe AD at the time this consensus project was done: azathioprine, cyclosporine A, dupilumab, methotrexate, mycophenolate mofetil and oral glucocorticosteroids. We focus on the geographically similar Northern European countries, whose healthcare systems, local preferences for AD management and reimbursement structures nonetheless differ significantly.Peer reviewe
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