ABSTRACT
Granular aluminum (grAl) is a promising high kinetic inductance material for detectors, amplifiers, and qubits. Here we model the grAl structure, consisting of pure aluminum grains separated by thin aluminum oxide barriers, as a network of Josephson junctions, and we calculate the dispersion relation and nonlinearity (self-Kerr and cross-Kerr coefficients). To experimentally study the electrodynamics of grAl thin films, we measure microwave resonators with open-boundary conditions and test the theoretical predictions in two limits. For low frequencies, we use standard microwave reflection measurements in a low-loss environment. The measured low-frequency modes are in agreement with our dispersion relation model, and we observe self-Kerr coefficients within an order of magnitude from our calculation starting from the grAl microstructure. Using a high-frequency setup, we measure the plasma frequency of the film around 70 GHz, in agreement with the analytical prediction.
ABSTRACT
BACKGROUND: Ocular trauma is a major cause of monocular blindness and visual impairment in industrialized countries. OBJECTIVES: The aim of this paper was to study epidemiology, causes, and clinical features of work-related and non-work-related eye injuries in a highly industrialized area of northern Italy. METHODS: All patients hospitalized for eye injuries were enrolled. Two 3-year periods were studied (1994-1996 and 2005-2007). The variables analyzed included sex, age, social class of the patients, nature of the injuring agent (e.g., metal, plastic, etc.), place where the accident occurred (e.g., home, work, etc.), and time of the year (e.g., summer, winter, etc.). RESULTS: We enrolled 1001 men and 129 women. There were no significant differences between the two 3-year periods as regards distribution of sex, age, and location. Road-related injuries significantly decreased (p < 0.004). Comparison of injuring agents showed a decrease in metallic agents (p < 0.001) and an increase in lime agents (p < 0.001). Analysis of the type of trauma showed a decrease in blunt traumas (p < 0.001) and an increase in chemical injuries (p < 0.001) and actinic keratitis (p = 0.002). In the second 3-year period, we found a significant increase in injuries in non-Italian subjects (p < 0.001). CONCLUSIONS: Work-related injuries were the major cause of eye trauma. Road accident-related eye injuries dropped significantly in the second 3-year period. The adoption of higher safety standards, as well as information and educational campaigns, can significantly reduce work-related and non-work-related eye injuries.
Subject(s)
Accidents, Occupational/prevention & control , Accidents, Occupational/statistics & numerical data , Eye Injuries/epidemiology , Eye Injuries/prevention & control , Inpatients/statistics & numerical data , Occupational Diseases/epidemiology , Occupational Diseases/prevention & control , Adolescent , Adult , Age Distribution , Aged , Aged, 80 and over , Child , Child, Preschool , Eye Injuries/diagnosis , Eye Injuries/etiology , Eye Injuries/therapy , Female , Humans , Incidence , Industry , Italy/epidemiology , Male , Middle Aged , Occupational Diseases/diagnosis , Occupational Diseases/etiology , Occupational Diseases/therapy , Risk Assessment , Risk Factors , Sex Distribution , Time Factors , Visual AcuityABSTRACT
We present a new type of cryogenic local velocity probe that operates in liquid helium (1 K < T < 4.2 K) and achieves a spatial resolution of ≈ 0.1 mm. The operating principle is based on the deflection of a micro-machined silicon cantilever which reflects the local fluid velocity. Deflection is probed using a superconducting niobium micro-resonator sputtered on the sensor and used as a strain gauge. We present the working principle and the design of the probe, as well as calibration measurements and velocity spectra obtained in a turbulent helium flow above and below the superfluid transition.
ABSTRACT
The mixed occurrence of s-wave and p-wave contributions in a first forbidden unique Gamow-Teller beta decay has been investigated for the first time by measuring the beta environmental fine structure (BEFS) in a 187Re crystalline compound. The experiment has been carried out with an array of eight AgReO4 thermal detectors operating at a temperature of approximately 100 mK. A fit of the observed BEFS spectrum indicates the p-wave electron emission as the dominant channel. The complete understanding of the BEFS distortion of the 187Re beta decay spectrum is crucial for future experiments aiming at the precise calorimetric measurement of the antineutrino mass.
