128 research outputs found
Spinor Dynamics-Driven Formation of a Dual-Beam Atom Laser
We demonstrate a novel dual-beam atom laser formed by outcoupling oppositely
polarized components of an F=1 spinor Bose-Einstein condensate whose Zeeman
sublevel populations have been coherently evolved through spin dynamics. The
condensate is formed through all-optical means using a single-beam running-wave
dipole trap. We create a condensate in the field-insensitive state, and
drive coherent spin-mixing evolution through adiabatic compression of the
initially weak trap. Such dual beams, number-correlated through the angular
momentum-conserving reaction , have been
proposed as tools to explore entanglement and squeezing in Bose-Einstein
condensates, and have potential use in precision phase measurements.Comment: 4 pages, 4 figure
A compact high-flux cold atom beam source
We report on an efficient and compact high-flux Cs atom beam source based on
a retro-reflected two-dimensional magneto-optical trap (2D MOT). We realize an
effective pushing field component by tilting the 2D MOT collimators towards a
separate three-dimensional magneto-optical trap (3D MOT) in ultra-high vacuum.
This technique significantly improved 3D MOT loading rates to greater than atoms/s using only 20 mW of total laser power for the source. When
operating below saturation, we achieve a maximum efficiency of atoms/s/W
Shell potentials for microgravity Bose-Einstein condensates
Extending the understanding of Bose-Einstein condensate (BEC) physics to new
geometries and topologies has a long and varied history in ultracold atomic
physics. One such new geometry is that of a bubble, where a condensate would be
confined to the surface of an ellipsoidal shell. Study of this geometry would
give insight into new collective modes, self-interference effects,
topology-dependent vortex behavior, dimensionality crossovers from thick to
thin shells, and the properties of condensates pushed into the ultradilute
limit. Here we discuss a proposal to implement a realistic experimental
framework for generating shell-geometry BEC using radiofrequency dressing of
magnetically-trapped samples. Such a tantalizing state of matter is
inaccessible terrestrially due to the distorting effect of gravity on
experimentally-feasible shell potentials. The debut of an orbital BEC machine
(NASA Cold Atom Laboratory, aboard the International Space Station) has enabled
the operation of quantum-gas experiments in a regime of perpetual freefall, and
thus has permitted the planning of microgravity shell-geometry BEC experiments.
We discuss specific experimental configurations, applicable inhomogeneities and
other experimental challenges, and outline potential experiments.Comment: 6 pages, 3 figure
Is diagnosis enough to guide interventions in mental health? Using case formulation in clinical practice
While diagnosis has traditionally been viewed as an essential concept in medicine, particularly when selecting treatments, we suggest that the use of diagnosis alone may be limited, particularly within mental health. The concept of clinical case formulation advocates for collaboratively working with patients to identify idiosyncratic aspects of their presentation and select interventions on this basis. Identifying individualized contributing factors, and how these could influence the person\u27s presentation, in addition to attending to personal strengths, may allow the clinician a deeper understanding of a patient, result in a more personalized treatment approach, and potentially provide a better clinical outcome.<br /
EPIdemiology of Surgery-Associated Acute Kidney Injury (EPIS-AKI) : Study protocol for a multicentre, observational trial
More than 300 million surgical procedures are performed each year. Acute kidney injury (AKI) is a common complication after major surgery and is associated with adverse short-term and long-term outcomes. However, there is a large variation in the incidence of reported AKI rates. The establishment of an accurate epidemiology of surgery-associated AKI is important for healthcare policy, quality initiatives, clinical trials, as well as for improving guidelines. The objective of the Epidemiology of Surgery-associated Acute Kidney Injury (EPIS-AKI) trial is to prospectively evaluate the epidemiology of AKI after major surgery using the latest Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI. EPIS-AKI is an international prospective, observational, multicentre cohort study including 10 000 patients undergoing major surgery who are subsequently admitted to the ICU or a similar high dependency unit. The primary endpoint is the incidence of AKI within 72 hours after surgery according to the KDIGO criteria. Secondary endpoints include use of renal replacement therapy (RRT), mortality during ICU and hospital stay, length of ICU and hospital stay and major adverse kidney events (combined endpoint consisting of persistent renal dysfunction, RRT and mortality) at day 90. Further, we will evaluate preoperative and intraoperative risk factors affecting the incidence of postoperative AKI. In an add-on analysis, we will assess urinary biomarkers for early detection of AKI. EPIS-AKI has been approved by the leading Ethics Committee of the Medical Council North Rhine-Westphalia, of the Westphalian Wilhelms-University Münster and the corresponding Ethics Committee at each participating site. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and used to design further AKI-related trials. Trial registration number NCT04165369
Autogenous shrinkage development and setting monitoring of slag cement concretes
info:eu-repo/semantics/publishe
Développement du retrait endogène et suivi de la prise de bétons formulés à base de ciment au laitier de haut-fourneau
info:eu-repo/semantics/publishe
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