2,161 research outputs found

    Determination of the Rb ng-series quantum defect by electric-field-induced resonant energy transfer between cold Rydberg atoms

    Full text link
    Resonant energy transfer between cold Rydberg atoms was used to determine Rydberg atom energy levels, at precisions approaching those obtainable in microwave spectroscopy. Laser cooled Rb atoms from a magneto-optical trap were optically excited to 32d Rydberg states. The two-atom process 32d(j=5/2) + 32d(j=5/2) -> 34p(j=3/2) + 30g is resonant at an electric field of approximately 0.3 V/cm. This process is driven by the electric dipole-dipole interaction, which is allowed due to the partial f character that the g state acquires in an electric field. The experimentally observed resonant field, together with the Stark map calculation is used to make a determination of the Rb ng-series quantum defect: delta_g (n=30) = 0.00405(6)

    Spectroscopic observation of resonant electric dipole-dipole interactions between cold Rydberg atoms

    Full text link
    Resonant electric dipole-dipole interactions between cold Rydberg atoms were observed using microwave spectroscopy. Laser-cooled Rb atoms in a magneto-optical trap were optically excited to 45d Rydberg states using a pulsed laser. A microwave pulse transferred a fraction of these Rydberg atoms to the 46p state. A second microwave pulse then drove atoms in the 45d state to the 46d state, and was used as a probe of interatomic interactions. The spectral width of this two-photon probe transition was found to depend on the presence of the 46p atoms, and is due to the resonant electric dipole-dipole interaction between 45d and 46p Rydberg atoms.Comment: 5 pages, 3 figures. Accepted for publication in Phys. Rev. Lett. Titles and e-print numbers of references added to this versio

    Asymptotic diophantine approximation:the multiplicative case

    Get PDF
    Let α\alpha and ÎČ\beta be irrational real numbers and 0<\F<1/30. We prove a precise estimate for the number of positive integers q≀Qq\leq Q that satisfy \|q\alpha\|\cdot\|q\beta\|<\F. If we choose \F as a function of QQ we get asymptotics as QQ gets large, provided \F Q grows quickly enough in terms of the (multiplicative) Diophantine type of (α,ÎČ)(\alpha,\beta), e.g., if (α,ÎČ)(\alpha,\beta) is a counterexample to Littlewood's conjecture then we only need that \F Q tends to infinity. Our result yields a new upper bound on sums of reciprocals of products of fractional parts, and sheds some light on a recent question of L\^{e} and Vaaler.Comment: To appear in Ramanujan Journa

    Exploring women's sensory experiences of undergoing colposcopy and related procedures: implications for preparatory sensory information provision

    Get PDF
    INTRODUCTION: Some women experience distress during colposcopy examinations which is partly related to women's fear, or experience, of pain during the procedure. However, little is known about women's sensory experiences of colposcopy (other than pain) or what might impact on these experiences. The aim of this study was to explore women's sensory experiences of colposcopy and related procedures and identify factors which influenced negative sensory experiences. METHODS: In-depth interviews were conducted with 23 women who had undergone, for the first time, a colposcopy (some with related procedures, including punch biopsies and loop excision) as part of follow-up for abnormal cervical cytology. Interviews were analysed thematically using the Framework Approach to organise the data and identify emerging higher-order themes. RESULTS: Women described a range of sensory experiences including pain or discomfort, cramping, stinging and cold sensations (due to the application of acetic acid to the cervix). Four key themes emerged as important aspects of the overall sensory experience: levels of pain, treatment-specific sensations, anaesthetic-specific sensations and solution-specific sensations. Factors that may influence women having a negative sensory experience were sensory expectations of the procedure(s) and lack of preparatory sensory information. DISCUSSION: Our study provides unique in-depth insight into women's sensory experiences of colposcopy and related procedures and suggests women require more preparatory sensory information. The issues identified as contributing to women having a negative sensory experience may help inform the development of pre-colposcopy information which may better prepare women with abnormal cervical cytology for follow-up examinations

    Absolute frequency measurements of 85Rb nF7/2 Rydberg states using purely optical detection

    Full text link
    A three-step laser excitation scheme is used to make absolute frequency measurements of highly excited nF7/2 Rydberg states in 85Rb for principal quantum numbers n=33-100. This work demonstrates the first absolute frequency measurements of rubidium Rydberg levels using a purely optical detection scheme. The Rydberg states are excited in a heated Rb vapour cell and Doppler free signals are detected via purely optical means. All of the frequency measurements are made using a wavemeter which is calibrated against a GPS disciplined self-referenced optical frequency comb. We find that the measured levels have a very high frequency stability, and are especially robust to electric fields. The apparatus has allowed measurements of the states to an accuracy of 8.0MHz. The new measurements are analysed by extracting the modified Rydberg-Ritz series parameters.Comment: 12 pages, 5 figures, submitted to New. J. Phy

    Socio-economic variations in anticipated adverse reactions to testing HPV positive: Implications for the introduction of primary HPV-based cervical screening

    Get PDF
    Some cervical cancer screening programmes are replacing cytology with human papillomavirus (HPV) DNA testing as the primary screening test. Concerns have been previously raised around the potential psychosocial impact of testing positive for HPV. We analysed socio-economic variations in anticipated adverse reactions to testing positive for HPV in women of screening age in the general population. A questionnaire was mailed to a random sample of 5553 women aged 20-64 in 2010, selected through primary care in Ireland. This included questions on: socio-economics; HPV knowledge; and women's anticipated adverse psychosocial responses to testing HPV positive (shame, anxiety, stigma and worry). Multivariable linear regression was used to identify socio-economic factors significantly associated with each anticipated adverse reaction. The response rate was 62% (n = 3470). In multivariate analyses, having only attained primary level education were significantly associated with higher mean scores for all four adverse outcomes. Religion was significantly associated with all four adverse outcomes. Age was associated with anxiety and worry; younger women (<30 years) had the highest mean scores. Being married/cohabiting was significantly associated with significantly lower shame and worry scores. Not working was significantly associated with higher mean anxiety and worry scores. Our large population-based survey found significant socio-economic variations in anticipated adverse reactions to testing HPV positive. In order to minimise possible negative impacts on screening uptake and alleviate potential adverse psychological effects of HPV-based screening on women, screening programmes may need to develop specific messages around HPV infection and HPV screening that target certain subgroups of women

    USL NASA/RECON project presentations at the 1985 ACM Computer Science Conference: Abstracts and visuals

    Get PDF
    This Working Paper Series entry represents the abstracts and visuals associated with presentations delivered by six USL NASA/RECON research team members at the above named conference. The presentations highlight various aspects of NASA contract activities pursued by the participants as they relate to individual research projects. The titles of the six presentations are as follows: (1) The Specification and Design of a Distributed Workstation; (2) An Innovative, Multidisciplinary Educational Program in Interactive Information Storage and Retrieval; (3) Critical Comparative Analysis of the Major Commercial IS and R Systems; (4) Design Criteria for a PC-Based Common User Interface to Remote Information Systems; (5) The Design of an Object-Oriented Graphics Interface; and (6) Knowledge-Based Information Retrieval: Techniques and Applications

    Effects of ischemia, preconditioning, and adenosine deaminase inhibition on interstitial adenosine levels and infarct size

    Full text link
    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41750/1/395_2004_Article_BF00796218.pd
    • 

    corecore