60 research outputs found
Geodetic observations to monitor natural hydraulic overpressure
The pressurization of a channel system occurs naturally through intake of rainfall and river drainage. The consequences of up to 1MPa pressurization include sudden uprise of water level, blockage of channels, increased erosion and possible triggering of seismicity, with associated diversified hazards. We model the expected deformation with the Finite Element Method and analytical approaches, and find that the pressures induce deformation which can be geodetically detected. The careful analysis of GNSS timeseries and tilt observations recovered in N-Italy demonstrates that the signals are observable. The observations of tilt have been made in karstic caves where a GPS station has been colocated on the surface. The uplift of GPS during underground floods is expected to be up to several mm and the titling at the microradians level for the tiltmeters. The results demonstrate that geodetic observations could be used to monitor internal pressure loading of the underground channel system. The research is based on the results described in Grillo et al. 2018 and Braitenberg et al. 2019.
References
Braitenberg C., Pivetta T., Barbolla D.F., Gabrovšek F., Devoti R., Nagy I. (2019) Terrain uplift due to natural hydrologic overpressure in karstic conduits, Scientific Reports, in press.
Grillo B., Braitenberg C., Nagy I., Devoti R., Zuliani D., Fabris P. (2018). Cansiglio Karst-Plateau: 10 years of geodetic-hydrological observations in seismically active northeast Italy. Pure and Applied Geophysics, Volume 175, Issue 5, 1765-1781, doi:10.1007/s00024-018-1860-7
Global Emergence of Trimethoprim/Sulfamethoxazole Resistance in Stenotrophomonas maltophilia Mediated by Acquisition of sul Genes
The first sul2 genes have been found in S. maltophilia from several different countries
Electrical characterization of electron cyclotron resonance deposited silicon nitride dual layer for enhanced Al/SiNx:H/InP metal–insulator–semiconductor structures fabrication
Costs and difficulties of recruiting patients to provide e-health support: pilot study in one primary care trust
<p>Abstract</p> <p>Background</p> <p>Better use of e-health services by patients could improve outcomes and reduce costs but there are concerns about inequalities of access. Previous research in outpatients suggested that anonymous personal email support may help patients with long term conditions to use e-health, but recruiting earlier in their 'journey' may benefit patients more. This pilot study explored the feasibility and cost of recruiting patients for an e-health intervention in one primary care trust.</p> <p>Methods</p> <p>The sample comprised 46 practices with total patient population of 250,000. We approached all practices using various methods, seeking collaboration to recruit patients via methods agreed with each practice. A detailed research diary was kept of time spent recruiting practices and patients. Researcher time was used to estimate costs. Patients who consented to participate were offered email support for their use of the Internet for health.</p> <p>Results</p> <p>Eighteen practices agreed to take part; we recruited 27 patients, most (23/27) from five practices. Practices agreed to recruit patients for an e-health intervention via waiting room leaflets (16), posters (16), practice nurses (15), doctors giving patients leaflets (5), a study website link (7), inclusion in planned mailshots (2), and a special mailshot to patients selected from practice computers (1). After low recruitment response we also recruited directly in five practices through research assistants giving leaflets to patients in waiting rooms. Ten practices recruited no patients. Those practices that were more difficult to recruit were less likely to recruit patients. Leaving leaflets for practice staff to distribute and placing posters in the practice were not effective in recruiting patients. Leaflets handed out by practice nurses and website links were more successful. The practice with lowest costs per patient recruited (£70) used a special mailshot to selected patients.</p> <p>Conclusion</p> <p>Recruitment via general practice was not successful and was therefore expensive. Direct to consumer methods and recruitment of patients in outpatients to offer email support may be more cost effective. If recruitment in general practice is required, contacting practices by letter and email, not following up non-responding practices, and recruiting patients with selected conditions by special mailshot may be the most cost-effective approach.</p
Deep levels in p+-n junctions fabricated by rapid thermal annealing of Mg or Mg/P implanted InP
Health communication in primary health care -A case study of ICT development for health promotion
Experimental observation of conductance transients in Al/SiNx:H/Si metal-insulator-semiconductor structures
Room temperature conductance transients in the SiNx:H/Si interface are reported. Silicon nitride thin films were directly deposited on silicon by the low temperature electron-cyclotron-resonance plasma method. The shape of the conductance transients varies with the frequency at which they are obtained. This behavior is explained in terms of a disorder-induced gap-state continuum model for the interfacial defects. A perfect agreement between experiment and theory is obtained proving the validity of the model. (C) 1997 American Institute of Physics
Deep levels in p(+)-n junctions fabricated by rapid thermal annealing of Mg or Mg/P implanted InP
In this work, we investigate the deep levels present in ion implanted and rapid thermal annealed (RTA) InP p(+)-n junctions. The samples were implanted with magnesium or coimplanted with magnesium and phosphorus. These levels were characterized using deep level transient spectroscopy (DLTS) and capacitance-voltage transient technique (CVTT). Seven majority deep levels located in the upper half of the band gap were detected in the junctions by using DLTS measurements, four of which (at 0.6, 0.45, 0.425, and 0.2 eV below the conduction band) result from RTA, while the origin of the other three levels (at 0.46, 0.25, and 0.27 eV below the conduction band) can be ascribed to implantation damage. An RTA-induced origin was assigned to a minority deep level at 1.33 eV above the valence band. From CVTT measurements, several characteristics of each trap were derived. Tentative assignments have been proposed for the physical nature of all deep levels
Characterization of the EL2 center in GaAs by optical admittance spectroscopy
We have measured the electron optical capture cross section, σ0n(hν), of EL2 (the most important native center in GaAs) using a new technique which we have recently developed: optical admittance spectroscopy. This is a spectroscopic technique based on the measurement of the capacitance and conductance of a junction under monochromatic light of energy hν. This technique allows the measurement of the spectrum σ0n(hν) of each center located in the band gap. We have measured the electron photoionization cross section of the EL2 center, σ0n(hν), at three different temperatures within a range limited at high temperature by thermal emission and at low temperature by photoquenching (a feature characteristic of EL2 below 140 K). The study of the experimental data reveals that this center has a more complex nature than that of a simple defect. It seems to behave like a family of very close levels corresponding to similar atomic structures and located near the midgap. These results also reveal the existence of a sha..
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