Pinch Resonances in a Radio Frequency Driven SQUID Ring-Resonator System

In this paper we present experimental data on the frequency domain response of a SQUID ring (a Josephson weak link enclosed by a thick superconducting ring) coupled to a radio frequency (rf) tank circuit resonator. We show that with the ring weakly hysteretic the resonance lineshape of this coupled system can display opposed fold bifurcations that appear to touch (pinch off). We demonstrate that for appropriate circuit parameters these pinch off lineshapes exist as solutions of the non-linear equations of motion for the system.Comment: 9 pages, 8 figures, Uploaded as implementing a policy of arXiving old paper

Giant Relaxation Oscillations in a Very Strongly Hysteretic SQUID ring-Tank Circuit System

In this paper we show that the radio frequency (rf) dynamical characteristics of a very strongly hysteretic SQUID ring, coupled to an rf tank circuit resonator, display relaxation oscillations. We demonstrate that the the overall form of these characteristics, together with the relaxation oscillations, can be modelled accurately by solving the quasi-classical non-linear equations of motion for the system. We suggest that in these very strongly hysteretic regimes SQUID ring-resonator systems may find application in novel logic and memory devices.Comment: 7 pages, 5 figures. Uploaded as implementing a policy of arXiving old paper

Pollutant dispersion in a developing valley cold-air pool

Pollutants are trapped and accumulate within cold-air pools, thereby affecting air quality. A numerical model is used to quantify the role of cold-air-pooling processes in the dispersion of air pollution in a developing cold-air pool within an alpine valley under decoupled stable conditions. Results indicate that the negatively buoyant downslope flows transport and mix pollutants into the valley to depths that depend on the temperature deficit of the flow and the ambient temperature structure inside the valley. Along the slopes, pollutants are generally entrained above the cold-air pool and detrained within the cold-air pool, largely above the ground-based inversion layer. The ability of the cold-air pool to dilute pollutants is quantified. The analysis shows that the downslope flows fill the valley with air from above, which is then largely trapped within the cold-air pool, and that dilution depends on where the pollutants are emitted with respect to the positions of the top of the ground-based inversion layer and cold-air pool, and on the slope wind speeds. Over the lower part of the slopes, the cold-air-pool-averaged concentrations are proportional to the slope wind speeds where the pollutants are emitted, and diminish as the cold-air pool deepens. Pollutants emitted within the ground-based inversion layer are largely trapped there. Pollutants emitted farther up the slopes detrain within the cold-air pool above the ground-based inversion layer, although some fraction, increasing with distance from the top of the slopes, penetrates into the ground-based inversion layer.Peer reviewe

Energy Down Conversion between Classical Electromagnetic Fields via a Quantum Mechanical SQUID Ring

We consider the interaction of a quantum mechanical SQUID ring with a classical resonator (a parallel $LC$ tank circuit). In our model we assume that the evolution of the ring maintains its quantum mechanical nature, even though the circuit to which it is coupled is treated classically. We show that when the SQUID ring is driven by a classical monochromatic microwave source, energy can be transferred between this input and the tank circuit, even when the frequency ratio between them is very large. Essentially, these calculations deal with the coupling between a single macroscopic quantum object (the SQUID ring) and a classical circuit measurement device where due account is taken of the non-perturbative behaviour of the ring and the concomitant non-linear interaction of the ring with this device.Comment: 7 pages, 6 figure

Consumer acceptance of patient-performed mobile teledermoscopy for the early detection of melanoma

Background Mobile teledermoscopy allows consumers to send images of skin lesions to a teledermatologist for remote diagnosis. Currently, technology acceptance of mobile teledermoscopy by people at high risk of melanoma is unknown. Objectives We aimed to determine the acceptance of mobile teledermoscopy by consumers based on perceived usefulness, ease of use, compatibility, attitude/intention, subjective norms, facilitators and trust before use. Consumer satisfaction was explored after use

A Fully Quantum Mechanical Model of a SQUID Ring Coupled to an Electromagnetic Field

A quantum system comprising of a monochromatic electromagnetic field coupled to a SQUID ring with sinusoidal non-linearity, is studied. A magnetostatic flux $\Phi_{x}$ is also threading the SQUID ring, and is used to control the coupling between the two systems. It is shown that for special values of $\Phi_{x}$ the system is strongly coupled. The time evolution of the system is studied. It is shown that exchange of energy takes place between the two modes and that the system becomes entangled. A second quasi-classical model that treats the electromagnetic field classically is also studied. A comparison between the fully quantum mechanical model with the electromagnetic field initially in a coherent state and the quasi-classical model, is made.Comment: 7 pages, 9 figures. Uploaded as implementing a policy of arXiving old paper

Occupational exposure to N-nitrosamines and pesticides and risk of pancreatic cancer

Objectives Animal evidence shows that N-nitrosamines and similar xenobiotic compounds are pancreatic carcinogens. We aimed to determine whether occupational exposure to N-nitrosamines or to pesticides increases risk of pancreatic cancer development. Methods Participants (504 cases, 643 controls) in a population-based case-control study (The Queensland Pancreatic Cancer Study) provided data on demographic, medical and lifestyle factors and lifetime job histories. Specific questions were asked regarding work in rubber and leather industries, metalworking jobs and occupational or direct use of pesticides on animals or crops. An occupational hygienist reviewed this information (blind to case status) to assess likelihood of exposure to N-nitrosamines and pesticides, and estimated level and frequency of such exposures. Results No associations were found for risk of pancreatic cancer and occupational exposure to N-nitrosamines (OR=0.85, 95% CI 0.51 to 1.42) and no associations were seen with level or frequency of exposure. No associations were observed for ever exposure to pesticides in general (OR=0.90, 95% CI 0.61 to 1.33) or to any of the pesticide subgroups. Stratification by history of cigarette smoking did not change these results. Conclusions This comprehensive analysis of a large case-control study does not support an association between occupational exposure to N-nitrosamines or pesticide use and risk of pancreatic cancer

The METCRAX II Field Experiment: A Study of Downslope Windstorm-Type Flows in Arizona\u2019s Meteor Crater

The second Meteor Crater Experiment (METCRAX II) was conducted in October 2013 at Arizona\u2019s Meteor Crater. The experiment was designed to investigate nighttime downslope windstorm 12type flows that form regularly above the inner southwest sidewall of the 1.2-km diameter crater as a southwesterly mesoscale katabatic flow cascades over the crater rim. The objective of METCRAX II is to determine the causes of these strong, intermittent, and turbulent inflows that bring warm-air intrusions into the southwest part of the crater. This article provides an overview of the scientific goals of the experiment; summarizes the measurements, the crater topography, and the synoptic meteorology of the study period; and presents initial analysis results

Quantum Statistics and Entanglement of Two Electromagnetic Field Modes Coupled via a Mesoscopic SQUID Ring

In this paper we investigate the behaviour of a fully quantum mechanical system consisting of a mesoscopic SQUID ring coupled to one or two electromagnetic field modes. We show that we can use a static magnetic flux threading the SQUID ring to control the transfer of energy, the entanglement and the statistical properties of the fields coupled to the ring. We also demonstrate that at, and around, certain values of static flux the effective coupling between the components of the system is large. The position of these regions in static flux is dependent on the energy level structure of the ring and the relative field mode frequencies, In these regions we find that the entanglement of states in the coupled system, and the energy transfer between its components, is strong.Comment: 15 pages, 19 figures, Uploaded as implementing a policy of arXiving old paper

Complications of Common Gynecologic Surgeries among HIV-Infected Women in the United States

Objective. To compare frequencies of complications among HIV-infected and-uninfected women undergoing common gynecological surgical procedures in inpatient settings. Methods. We used 1994–2007 data from the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project, a nationally representative sample of inpatient hospitalizations. Our analysis included discharge records of women aged ≥15 undergoing hysterectomy, oophorectomy, salpingectomy for ectopic pregnancy, bilateral tubal sterilization, or dilation and curettage. Associations between HIV infection status and surgical complications were evaluated in multivariable logistic regression models, adjusting for key covariates. Results. For each surgery, HIV infection was associated with experiencing ≥1 complication. Adjusted ORs ranged from 2.0 (95% confidence interval (CI): 1.7, 2.2) for hysterectomy with oophorectomy to 3.1 (95% CI: 2.4, 4.0) for bilateral tubal sterilization with no comorbidity present. HIV infection was positively associated with extended length of stay and infectious complications of all of the surgeries examined. For some surgeries, it was positively associated with transfusion and anemia due to acute blood loss. Among HIV-infected women, the odds of infectious and other complications did not decrease between 1994–2000 and 2001–2007. Conclusion. HIV infection was associated with elevated frequencies of complications of gynecologic surgeries in the US, even in the era of HAART