Simulation of a high-speed demultiplexer based on two-photon absorption in semiconductor devices

In this paper, we present a theoretical model of an all-optical demultiplexer based on two-photon absorption in a specially designed semiconductor micro-cavity for use in an optical time division multiplexed system. We show that it is possible to achieve error-free demultiplexing of a 250 Gbit/s OTDM signal (25 × 10 Gbit/s channels) using a control-to-signal peak pulse power ratios of around 30:1 with a device bandwidth of approximately 30 GHz

Dispersion monitoring for high-speed WDM networks via two-photon absorption in a semiconductor microcavity

Due to the continued demand for bandwidth, network operators have to increase the data rates at which individual wavelengths operate at. As these data rates will exceed 100 Gbit/s in the next 5-10 years, it will be crucial to be able to monitor and compensate for the amount of chromatic dispersion encountered by individual wavelength channels. This paper will focus on the use of the novel nonlinear optical-to-electrical conversion process of two-photon absorption (TPA) for dispersion monitoring. By incorporating a specially designed semiconductor microcavity, the TPA response becomes wavelength dependent, thus allowing simultaneous channel selection and monitoring without the need for external wavelength filterin

Edge detection versus videodensitometry for quantitative angiographic assessment of directional coronary atherectomy

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All-optical sampling utilising two-photon absorption in semiconductor microcavity

A highly-efficient optical sampling system based on Two-Photon Absorption in a semiconductor micro-cavity is presented. The sensitivity of the sampling system is calculated to be 0.1mW² with a temporal resolution of 2ps

Effectiveness of the inclusive design wheel in practice: Lessons from five pilot projects

The Inclusive Design Wheel (IDW) is an established inclusive con-cept design process, emphasizing iteration and early-stage evaluation. However, a structured evaluation of its effectiveness in practice has not been previously conducted. This paper describes how the IDW process was adapted for use in the design of digital mobility services. It was then trialled on five pilot projects in Italy, Spain, Belgium and the Netherlands. Questionnaires were completed by participants (both pilot partners and end-users) and interviews were held with pilot partners at the end of the project. Initial insights from the pilot experiences and the evaluation are described. The pilot teams found the IDW helpful and particularly valued its help in structuring the design process and offering clear steps and tools. Insights for improving the IDW focus on the importance and role of co-creation, issues with recording iteration and the balance between structure and flexibility. Implications are highlighted for improving the Inclusive Design Wheel and for inclusive design processes more generally.Peer ReviewedPreprin

Successful multiple segment coronary angioplasty: Effect of completeness of revascularization in single-vessel multilesions and multivessels

A long-term follow-up study was performed to evaluate the long-term value of performing multiple dilatations according to their procedural (single-vessel multilesion or mutltivessel dilatations) and anatomic types (single-vessel disease with multiple dilatations or multivessel disease dilatations with complete and incomplete revascularization). From 1980 until 1988, 248 patients met the following criteria: (1) at least two lesions dilated (range: 2 to 4) and (2) all attempted lesions successfully dilated. The mean length of follow-up was 33 months. The end points analyzed were death, myocardial infarction, redilatation, and bypass surgery. No differences were found for these events between the single-vessel multilesion group (144 patients) and the multivessel group (104 patients). The 4.5-year probability of event-free survival was 68% and 70%, respectively, for the multilesion group and the multivessel group. In the event-free patients, 57% versus 59% were asymptomatic and 45% versus 46% were not taking antianginal drugs. In the anatomic subgroups, there were less event-free patients in the cohort of incompletely revascularized multivessel disease patients (55% of 55 patients) when compared with the cohort of those who were completely revascularized (84% of 79 patients) or when compared with the single-vessel disease multiple dilatation patients (74% of 107 patients). The 4.5-year event-free survival probability for each group was 44%, 78%, and 74%, respectively. This difference was caused by more infarctions (9% versus 2% versus 4%, respectively) and bypass operations in the multivessel disease, incomplete revascularization group (20% versus 5% versus 10%, respectively). In event-free patients, improvement of angina was similar and was documented in over 85% of patients in each group. Furthermore, the number of asymptomatic patients at follow-up was similar in all groups except that within the incomplete revascularization group, less patients were free of antianginal drugs (21% versus 51% versus 48%). Finally, 48% of the entire cohort performed an exercise test 4.6 months (mean) after dilatation and no difference was found in any of the variables in any group. About 10% of the patients experienced angina and approximately 30% had a positive exercise test for ischemia by ST segment criteria. The functional performance in every group was over 90% of the predicted work load. These results suggest that completeness of revascularization in multivessel disease patients is an important prognostic variable. However, the symptomatic improvement after dilatation is very rewarding in all subsets of patients and argues in favor of the continued use of multiple dilatations as a treatment strategy

Magnetic phase separation in ordered alloys

We present a lattice model to study the equilibrium phase diagram of ordered alloys with one magnetic component that exhibits a low temperature phase separation between paramagnetic and ferromagnetic phases. The model is constructed from the experimental facts observed in Cu$_{3-x}$AlMn$_{x}$ and it includes coupling between configurational and magnetic degrees of freedom which are appropriated for reproducing the low temperature miscibility gap. The essential ingredient for the occurrence of such a coexistence region is the development of ferromagnetic order induced by the long-range atomic order of the magnetic component. A comparative study of both mean-field and Monte Carlo solutions is presented. Moreover, the model may enable the study of the structure of the ferromagnetic domains embedded in the non-magnetic matrix. This is relevant in relation to phenomena such as magnetoresistance and paramagnetism.Comment: 12 pages, 11 figures, accepted in Phys. Rev.

Hemodynamic and Metabolic Observations Associated with Intracoronary Stenting for Acute Closure Following Percutaneous Transluminal Coronary Angioplasty

Emergency stent implantation appears to be an effective method for restoring antegrade flow in case of an abrupt coronary occlusion during percutaneous transluminal coronary angioplasty (PTCA). In this case report, hemodynamic and metabolic changes throughout abrupt coronary closure and stent implantation were followed in order to study the efficacy of this bail out technique in restoring metabolic and hemodynamic disturbances due to acute coronary occlusion. Copyrigh

Comparative angiographic quantitative analysis of the immediate efficacy of coronary atherectomy with balloon angioplasty, stenting, and rotational ablation

Interventional cardiology has branched in two directions: devices that primarily dilate coronary stenoses and those that debulk coronary tissue. Presently the optimum coronary intervention has not been found. While patients are awaiting randomized trials, a comparison based on matched quantitative coronary analysis may be useful to evaluate results of new interventional techniques. Therefore we compared 51 patients undergoing atherectomy with individually matched patients who were undergoing balloon angioplasty and stenting. The lesions were matched according to location of stenosis and reference diameter. Atherectomy and stenting resulted in larger gains in minimal luminal diameter compared with conventional balloon angioplasty. The minimal luminal diameter was increased from 1.2 +/- 0.4 mm to 2.6 +/- 0.4 mm in the atherectomy group and from 1.2 +/- 0.3 mm to 1.9 +/- 0.4 mm in the angioplasty group (p less than 0.00001). Atherectomy and stenting resulted in similar gains in minimum luminal diameter (1.4 mm vs 1.3 mm, p = NS). In addition, atherectomy and stenting appear to be more effective in resisting elastic recoil because of tissue removal and an intrinsic dilating effect, respectively. In matched populations directional atherectomy and stenting appear to be more effective intracoronary interventional devices than balloon angioplasty based on the immediate results. However, atherectomy is limited in smaller coronary vessels because of its larger size