Quantum and Classical in Adiabatic Computation

Adiabatic transport provides a powerful way to manipulate quantum states. By preparing a system in a readily initialised state and then slowly changing its Hamiltonian, one may achieve quantum states that would otherwise be inaccessible. Moreover, a judicious choice of final Hamiltonian whose groundstate encodes the solution to a problem allows adiabatic transport to be used for universal quantum computation. However, the dephasing effects of the environment limit the quantum correlations that an open system can support and degrade the power of such adiabatic computation. We quantify this effect by allowing the system to evolve over a restricted set of quantum states, providing a link between physically inspired classical optimisation algorithms and quantum adiabatic optimisation. This new perspective allows us to develop benchmarks to bound the quantum correlations harnessed by an adiabatic computation. We apply these to the D-Wave Vesuvius machine with revealing - though inconclusive - results

A Structured Framework and Resources to Use to Get Your Medical Education Work Published.

IntroductionMedical educators often have great ideas for medical education scholarship but have difficulty converting their educational abstract or project into a published manuscript.MethodsDuring this workshop, participants addressed common challenges in developing an educational manuscript. In small-group case scenarios, participants discovered the importance of the "So what?" in making the case for their project. Incorporating conceptual frameworks, participants chose appropriate outcome metrics, discussed how to frame the discussion section, and ensured appropriate journal fit. After each small-group exercise, large-group discussions allowed the small groups to report back so that facilitators could highlight and reinforce key learning points. At the conclusion of the workshop, participants left with a checklist for creating an educational manuscript and an additional resources document to assist them in avoiding common pitfalls when turning their educational abstract/project into a publishable manuscript.ResultsThis workshop was presented in 2016 and 2017. Presenter evaluations were completed by 33 participants; 11 completed conference evaluations. The mean overall rating on presenter evaluations was 4.55 out of 5, while the conference evaluations mean was 3.73 out of 4. Comments provided on both evaluation tools highlighted the perceived effectiveness of the delivery and content. More than 50% of respondents stated that they planned to incorporate the use of conceptual frameworks in future work.DiscussionThis workshop helped participants address common challenges by providing opportunities for hands-on practice as well as tips and resources for use when submitting a medical education manuscript for publication

Robotic surgery for gynecologic cancers: indications, techniques and controversies.

Minimally invasive surgery for gynecologic cancers is associated with fewer postoperative complications including less blood loss and quicker recovery time compared to traditional laparotomy. The robotic platform has allowed patients access to minimally invasive surgery due to its increased utilization by gynecologic oncologists. Many surgeons have embraced the robotic platform due to its technological advances over traditional laparoscopy including high-definition 3D optics, wristed instrumentation, camera stability and improved ergonomics. While robotic surgery continues as a mainstay in the management of gynecologic cancers, it remains controversial in regards to its cost effectiveness and more recently, its long-term impact on clinical and oncologic outcomes. A strong component of the justification of this surgical platform is based on extrapolated data from traditional laparoscopy despite limited prospective randomized trials for robotic-assisted surgery. In this review, we highlight the use of robotic surgery in the management of gynecologic cancers in special populations: fertility sparing patients, the morbidly obese, the elderly, and patients with a favorable response to neoadjuvant chemotherapy

A mathematical model of low-head oxygenators

AbstractA mathematical model is presented that predicts the performance of low-head oxygenators (LHO). Experimentally determined values of G20 for a single hole in a flooded orifice plate were used as the basis to develop a mathematical model that can be used to predict LHO performance under a variety of design and operating conditions. Model predictions were compared to two published studies. The model predicted the published data for dissolved oxygen levels in the departing effluent within 2–3%, oxygen absorption efficiencies within 5–6%, and total gas pressures within 1%. The mathematical model is thoroughly developed including an analysis of numerical stability and necessary restrictions to assure stability and accuracy. Convergence based solely upon effluent values was not sufficient to produce accurate results, but required additional criteria of requiring a minimum number of chamber flushings prior to convergence checking. The model was used to demonstrate its utility in predicting the effects of G/L ratio on gas absorption efficiency, effluent gas conditions and the effects of number of LHO chambers used. This model allows the designer or operator of an LHO to easily make design and operational decisions by modifying the input parameters and observing the exit conditions and performance indicators

Decaying shock studies of phase transitions in MgOSiO2 systems: implications for the Super-Earths interiors

We report an experimental study of the phase diagrams of periclase (MgO), enstatite (MgSiO3) and forsterite (Mg2SiO4) at high pressures. We investigated with laser driven decaying shocks the pressure/temperature curves of MgO, MgSiO3 and Mg2SiO4 between 0.2-1.2 TPa, 0.12-0.5 TPa and 0.2-0.85 TPa respectively. A melting signature has been observed in MgO at 0.47 TPa and 9860 K, while no phase changes were observed neither in MgSiO3 nor in Mg2SiO4. An increasing of reflectivity of MgO, MgSiO3 and Mg2SiO4 liquids have been detected at 0.55 TPa -12 760 K, 0.15 TPa - 7540 K, 0.2 TPa - 5800 K, respectively. In contrast to SiO2, melting and metallization of these compounds do not coincide implying the presence of poor electrically conducting liquids close to the melting lines. This has important implications for the generation of dynamos in Super-earths mantles

Size effects in statistical fracture

We review statistical theories and numerical methods employed to consider the sample size dependence of the failure strength distribution of disordered materials. We first overview the analytical predictions of extreme value statistics and fiber bundle models and discuss their limitations. Next, we review energetic and geometric approaches to fracture size effects for specimens with a flaw. Finally, we overview the numerical simulations of lattice models and compare with theoretical models.Comment: review article 19 pages, 5 figure

Properties of large scale ultra-high temperature ceramic matrix composites made by filament winding and spark plasma sintering

In this paper, for the first time, we report the manufacturing and characterization of large UHTCMCs discs, made of a ZrB2/SiC matrix reinforced with PyC-coated PAN-based carbon fibres. This work was the result of a long term collaboration between different institutions and shows how it is possible to scale-up the production process of UHTCMCs for the fabrication of large components. 150 mm large discs were produced by filament winding and consolidated by spark plasma sintering and specimens were machined to test a large set of material properties at room and elevated temperature (up to 1800 °C). The extensive characterization revealed a new material with mechanical behaviour similar to CMCs, but with intrinsic higher thermal stability. Furthermore, the scale-up demonstrated in this work increases the appeal of UHTCMCs in sectors such as aerospace, where severe operating conditions limit the application of conventional materials

Link between laboratory and astrophysical radiative shocks

This work provides analytical solutions describing the post-shock structure of radiative shocks growing in astrophysics and in laboratory. The equations including a cooling function $\Lambda \propto \rho^{\epsilon} P^{\zeta} x^{\theta}$ are solved for any values of the exponents $\epsilon$, $\zeta$ and $\theta$. This modeling is appropriate to astrophysics as the observed radiative shocks arise in optically thin media. In contrast, in laboratory, radiative shocks performed using high-power lasers present a radiative precursor because the plasma is more or less optically thick. We study the post-shock region in the laboratory case and compare with astrophysical shock structure. In addition, we attempt to use the same equations to describe the radiative precursor, but the cooling function is slightly modified. In future experiments we will probe the PSR using X-ray diagnostics. These new experimental results will allow to validate our astrophysical numerical codes