Tunable Flux Qubit manipulated by fast pulses: operating requirements, dissipation and decoherence

A double SQUID manipulated by fast magnetic flux pulses can be used as a tunable flux qubit. In this paper we study the requirements for the qubit operation, and evaluate dissipation and decoherence due to the manipulation for a typical system. Furthermore, we discuss the possibility to use an integrated Rapid Single Flux Quantum logic for the qubit control.Comment: 6 pages, 4 figure

A tunable rf SQUID manipulated as flux and phase qubit

We report on two different manipulation procedures of a tunable rf SQUID. First, we operate this system as a flux qubit, where the coherent evolution between the two flux states is induced by a rapid change of the energy potential, turning it from a double well into a single well. The measured coherent Larmor-like oscillation of the retrapping probability in one of the wells has a frequency ranging from 6 to 20 GHz, with a theoretically expected upper limit of 40 GHz. Furthermore, here we also report a manipulation of the same device as a phase qubit. In the phase regime, the manipulation of the energy states is realized by applying a resonant microwave drive. In spite of the conceptual difference between these two manipulation procedures, the measured decay times of Larmor oscillation and microwave-driven Rabi oscillation are rather similar. Due to the higher frequency of the Larmor oscillations, the microwave-free qubit manipulation allows for much faster coherent operations.Comment: Proceedings of Nobel Symposium "Qubits for future quantum computers", Goeteborg, Sweden, May 25-28, 2009; to appear in Physica Script

Paper Tiger or Game-Changer? Challenges of and Opportunities for EU Engagement with the Eurasian Economic Union. Bruges Regional Integration & Global Governance Papers (BRIGG) 1/2015.

The Eurasian Economic Union (EEU) started work on 1 January 2015. Considered as Russia’s response to the EU’s Eastern Partnership (EaP), it has been almost ignored in Brussels. However, with the Ukraine crisis and the deteriorating relations with Moscow, some European leaders have begun to reconsider Putin’s proposal for a region-to-region engagement. This paper tries to analyse under which conditions this could represent a long-term solution for a new European order. First, it is argued that the EEU is still far from being a credible international interlocutor. Second, Russia’s commitment to international trade rules and liberalization is questioned, whereas its geopolitical objectives seem predominant. EU engagement with the EEU in Ukraine would mean, in the short term, legitimizing Russia’s vision of a ‘bipolar Europe’ divided in spheres of influence. In the long run, prospects for inter-regional cooperation remain open, but the way to go is long and full of obstacles

Paper tiger or game-changer? Challenges of and opportunities for EU engagement with the Eurasian Economic Union. Bruges Regional Integration & Global Governance Papers 1/2015

The Eurasian Economic Union (EEU) started work on 1 January 2015. Considered as Russia’s response to the EU’s Eastern Partnership (EaP), it has been almost ignored in Brussels. However, with the Ukraine crisis and the deteriorating relations with Moscow, some European leaders have begun to reconsider Putin’s proposal for a region-to-region engagement. This paper tries to analyse under which conditions this could represent a long-term solution for a new European order. First, it is argued that the EEU is still far from being a credible international interlocutor. Second, Russia’s commitment to international trade rules and liberalization is questioned, whereas its geopolitical objectives seem predominant. EU engagement with the EEU in Ukraine would mean, in the short term, legitimizing Russia’s vision of a ‘bipolar Europe’ divided in spheres of influence. In the long run, prospects for inter-regional cooperation remain open, but the way to go is long and full of obstacles

Droplet breakup driven by shear thinning solutions in a microfluidic T-Junction

Droplet-based microfluidics turned out to be an efficient and adjustable platform for digital analysis, encapsulation of cells, drug formulation, and polymerase chain reaction. Typically, for most biomedical applications, the handling of complex, non-Newtonian fluids is involved, e.g. synovial and salivary fluids, collagen, and gel scaffolds. In this study we investigate the problem of droplet formation occurring in a microfluidic T-shaped junction, when the continuous phase is made of shear thinning liquids. At first, we review in detail the breakup process providing extensive, side-by-side comparisons between Newtonian and non-Newtonian liquids over unexplored ranges of flow conditions and viscous responses. The non-Newtonian liquid carrying the droplets is made of Xanthan solutions, a stiff rod-like polysaccharide displaying a marked shear thinning rheology. By defining an effective Capillary number, a simple yet effective methodology is used to account for the shear-dependent viscous response occurring at the breakup. The droplet size can be predicted over a wide range of flow conditions simply by knowing the rheology of the bulk continuous phase. Experimental results are complemented with numerical simulations of purely shear thinning fluids using Lattice Boltzmann models. The good agreement between the experimental and numerical data confirm the validity of the proposed rescaling with the effective Capillary number.Comment: Manuscript: 11 pages 5 figures, 65 References. Textual Supplemental Material: 6 pages 3 figure. Video Supplemental Materials: 2 movie

A deep learning approach for object counting on embedded systems

openThis thesis discusses the implementation of a piece counter, based on deep learning methods, to be used on industrial packaging lines. In particular, we aim at obtaining a system capable of detecting small objects (diameter < 1cm) and that can be executed on embedded devices. The object detection models SSD MOBILENET V2 and SSD RESNET 50 , after a brief analysis of their characteristics, result to be the most suitable for this application and their performance is measured by using bolts of different sizes as test object to be detected. In the experimental results, the pros and cons of the two models are analyzed in terms of accuracy, inference time and efficiency. All tests are performed on the development board NVIDIA JETSON NANO in order to optimize models using TensorRT and evaluate the results

Evaluation of the Effectiveness of Femoral Neck Prophylactic Surgery in Elderly Osteoporotic Patiens to Prevent Hip Fractures

The aim of our RCT was to evaluate safety and efficacy of a new device called Prevention Nail System (PNS) developed for the prevention of femoral neck fractures (FNFs) in patients with severe osteoporosis. The PNS is a titanium screw with a hydroxyapatite coating implanted in the femoral neck in order to reinforce it. We enrolled patients with: FNF; age ≥65 years; DXA of the noninjured hip with a T-score ≤ −2.5 SD. In the fractured hip patients received standard treatment while the contralateral hip was randomized either to receive PNS (group A) or not: control group (B). During each follow-up (FU) at 3, 12 and 24 months, DXA, CT and X-rays of the reinforced hip were performed. The mean age was 83 years and the preoperative DXA was −3.3 SD in both groups. The walking ability of patients with PNS were comparable to controls. The CT scan showed good integration of the PNS in the bone. At the longest available FU 23 patients reported one or more falls. 16 nonfemoral fractures were recorded: 10 (A) and 6 (B) and 6 contralateral hip fractures (CHFs): 3 in the PNS group and 3 in the control group. In A all CHFs occurred within 1 month after surgery and there was a difficult screw placement during surgery, in the control group the CHFs were consequence of a fall (6 months to 2 years after the first FNF). No statistical differences were reported between groups A and B. In conclusion, the device was well tolerated; CHFs in the PNS group should be considered a technical error due to the surgical instruments. Safety of the device can be increased by improving the instruments to reduce the risk of iatrogenic fractures