518 research outputs found
Stray Magnetic Field Compensation with a Scalar Atomic Magnetometer
We describe a system for the compensation of time-dependent stray magnetic
fields using a dual channel scalar magnetometer based on non-linear Faraday
rotation in synchronously optically pumped Cs vapour. We detail the active
control strategy, with an emphasis on the electronic circuitry, based on a
simple phase-locked-loop integrated circuit. The performance and limits of the
system developed are tested and discussed. The system was applied to
significantly improve the detection of free induction decay signals from
protons of remotely magnetized water precessing in an ultra-low magnetic field.Comment: 8 pages, 6 figures, 31 refs, v2 (with minor improvements) appearing
in Rev.Sc.Instr. June 201
Linee Guida per la conservazione delle architetture di interesse archeologico e l’esperienza del commissariamento delle aree archeologiche di Roma e Ostia Antica.
Linee Guida per la conservazione delle architetture di interesse archeologico e l’esperienza del commissariamento delle aree archeologiche di Roma e Ostia Antica
Small ruminant Gongylonema pulchrum infection in the South West Algerian desert: prevalence of a sporadic zoonosis
Individual faecal samples were randomly collected from the rectum of goats (n = 120) and sheep (n = 182)
bred in four distinct areas of the South West Algerian desert. All the samples were examined by faecal
flotation technique. A range of gastro-intestinal parasites was recorded by microscopic examination. Special
reference was given to potentially zoonotic nematodes. Typical G. pulchrum eggs were detected as mixed or
single infections in 9.3% of the animals (15% of goats and 5.5% of sheep). Goats were statistically (OR=3.04
[1.35-6.83]) more likely to harbor G. pulchrum infections than sheep. Animals older than 1 year of age were
more likely to be infected with G. pulchrum than younger ones, but these differences di not reach statistically
significant values. Monitoring human infections represents an imperative need of modern society. Anyone
working with sheep and goats or sharing the same environment with them and physicians should be aware of
gongylonemiasis and other potentially zoonotic nematode infections due to ovicaprines, though considered not
life-threatening, sporadic or neglected
Fast, cheap, and scalable magnetic tracker with an array of magnetoresistors
We present the hardware of a cheap multi-sensor magnetometric setup where a
relatively large set of magnetic field components is measured in several
positions by calibrated magnetoresistive detectors. The setup is developed with
the scope of mapping the (inhomogeneous) field generated by a known magnetic
source, which is measured as superimposed to the (homogeneous) geomagnetic
field. The final goal is to use the data produced by this hardware to
reconstruct position and orientation of the magnetic source with respect to the
sensor frame, simultaneously with the orientation of the frame with respect to
the environmental field. Possible applications of the setup are shortly
discussed, together with a synthetic description of the data elaboration and
analysis.Comment: 10 pages, 7 figures, 30 ref
Satellite and ground-based radar interferometry for detection and monitoring of structural instability in archaeological sites
Effect of Substrates and Thermal Treatments on Metalorganic Chemical Vapor Deposition-Grown Sb2Te3 Thin Films
Antimony telluride (Sb2Te3) thin films were obtained by metalorganic chemical vapor deposition (MOCVD). The films were grown on crystalline Si(100) and Al2O3(0001) and amorphous SiO2 and alpha-Al2O3 substrates. Their structural properties were compared with those of the Sb2Te3/Si(111) heterostructure. In addition to the effect of the substrate, the influence of pre- and post-growth thermal annealing is also presented. The quality of the films is discussed by comparing their morphological properties, such as roughness and granularity, and ascertaining their crystallinity and their in-plane and out-of-plane orientation
Validation of a fast and accurate magnetic tracker operating in the environmental field
We characterize the performance of a system based on a magnetoresistor array.
This instrument is developed to map the magnetic field, and to track a dipolar
magnetic source in the presence of a static homogeneous field. The position and
orientation of the magnetic source with respect to the sensor frame is
retrieved together with the orientation of the frame with respect to the
environmental field. A nonlinear best-fit procedure is used, and its precision,
time performance, and reliability are analyzed. This analysis is performed in
view of the practical application for which the system is designed that is an
eye-tracking diagnostics and rehabilitative tool for medical purposes, which
require high speed (~Sa/s) and sub-millimetric spatial resolution. A
throughout investigation on the results makes it possible to list several
observations, suggestions, and hints, which will be useful in the design of
similar setups.Comment: 12 pages, 9 figs, 15 ref
Legal medicine aspects of female sterilization: our experience
IntroductionThe most frequent sterilization procedures include postpartum tubal ligation, laparoscopic tubal disruption or salpingectomy, and hysteroscopic tubal occlusion. It may be performed via laparoscopy, mini-laparotomy, or hysteroscopy. Safety, efficacy, short-term complications, long-term complications, and non-contraceptive benefits of sterilization are different for each procedure. Female sterilization has become an important professional liability problem in obstetrics and gynecology.Materials and methodsWe analyzed 6 cases of surgical sterilization that have been the subject of civil proceedings. We review indications, contraindications, and complications associated with each sterilization procedure.ResultsIn our small number of cases, women who have undergone sterilization performed negligently are entitled to recover damages for wrongful conception, negligence, and wrongful birth. We also consider the issue of female sterilization of minors.DiscussionTubal sterilization can be performed with different techniques, chosen in light of the various situations involved, with the goal of reducing as many as possible any failures. Thorough and complete communication of information is of primary importance.ConclusionSterilization is the most widely used birth control method around the world. The procedure is generally safe and highly effective. As reported in the literature, the decision concerning method depends on the setting, the surgeon’s experience, the country’s economic development, and the woman’s preference, but we think that some techniques present a greater risk of failure and expose the surgeon to malpractice litigation
A Wearable Wireless Magnetic Eye-Tracker, in-vitro and in-vivo tests
A wireless, wearable magnetic eye tracker is described and characterized. The proposed instrumentation enables simultaneous evaluation of eye and head angular displacements. Such a system can be used to determine the absolute gaze direction as well as to analyze spontaneous eye re-orientation in response to stimuli consisting in head rotations. The latter feature has implications to analyze the vestibulo-ocular reflex and constitutes an interesting opportunity to develop medical (oto-neurological) diagnostics. Details of data analysis are reported together with some results obtained in-vivo or with simple mechanical simulators that enable measurements under controlled conditions
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