Relevant Closure Research Articles

Magnetic dipole moments as a strong signature for alpha -clustering in even-even self-conjugate nuclei

We investigate the magnetic dipole moments in even-even self-conjugate nuclei from ^{12}C to ^{48}Cr. For these nuclei, the measured gyromagnetic factors of excited states turn out to assume the same value of g approx + 0.5 within statistical errors. This peculiar feature can be interpreted on the basis of collective excitations of alpha -clusters. Analogously, the behaviour of the same observable is studied for all isotopes obtained by adding one or two neutrons to the considered self-conjugate nuclei. It is found that for the N = Z + 1 isotopes the alpha -cluster structure hardly contributes to the observed negative g- factor value, corroborating molecular alpha -cluster models. The addition of a further neutron, however, restores the original alpha -cluster g-factors, except for the semi-magic isotopes, in which the deviations from g approx + 0.5 can be associated with the relevant shell closures. Secondly, we analyze the same observable in the framework of a macroscopic alpha -cluster model on a finite lattice of side length L. We focus on the discretization effects induced in the magnetic dipole moments of the 2_1^+ and the 3_1^- states of ^{12}C at different values of the lattice spacing a.

The bystander effect: Impact of rural hospital closures on the operations and financial well-being of surrounding healthcare institutions.

There is presently a rural hospital shortage in the United States with 180 closures since 2005 and hundreds of institutions in financial peril. Although the hospital closure phenomenon is well-established, less is known about the spillover impact on the operations and financial wellbeing of surrounding hospitals. This preliminary study quantified how discrete rural hospital closures impact institutions in their regional proximity, finding a significant increase in inpatient admissions and emergency department visits for these "bystander hospitals". Using a repository of rural hospital closures collected by the UNC Sheps Center for Health Services Research, we identified closures over the past 15 years. Criteria for inclusion were hospitals that had been fully closed between 2005-2016 and with >25-bed capacity. We then designated surrounding hospitals within a 30-mile radius of each closed hospital as "bystander hospitals." We examined the average rate-of-change for inpatient admissions and emergency department visits in surrounding hospitals both two years before and after relevant hospital closures. We identified 53 hospital closures and 93 bystander hospitals meeting our criteria during the study period. With respect to geographic distribution, 66% of closures were in the Southern US, including 21% in Appalachia. Average emergency department visits increased by 3.59% two years prior to a hospital's closure; however, at two years post-closure the average rate of increase rose to 10.22% (F (4,47) = 2.77, p = 0.0375). Average bystander hospital admissions fell by 5.73% in the two years preceding the hospital closure but increased 1.17% in the two years after (F (4,46) = 3.05, p = 0.0259). These findings predict a daunting future for rural healthcare. While previous literature has described the acute effects hospital closures have on communities, this study suggests a significant spillover effect on hospitals within the geographic region and a cyclical process at play in the rural healthcare sector. In the absence of significant public health assistance in regions affected by closures, poor health outcomes, including "diseases of despair," are likely to continue proliferating, disproportionately affecting the most vulnerable. In the COVID-19 era, it will be especially necessary to focus on hospital closures given increased risk of maintaining solvency due to delayed and deferred care atop already tight margins.

Phenomenological model of disturbance waves in annular two-phase flow

A new, phenomenological, model of disturbance waves in annular two-phase flow is presented. The model builds upon the three-field (gas, drops and film) one-dimensional model of annular two-phase flow by considering the disturbance waves as an additional fluid field, traveling over a thin liquid base film, along with its own mass, momentum and energy conservation equations. The waves are modeled as fluid particles characterized by basic macroscopic parameters such as the wave shape factor (amplitude/width) and the wave number density (spatial frequency of waves). Phase change is considered and relevant closure models are developed for the field mass and momentum exchange rates (drop entrainment/deposition and waves/base film interactions). A Boltzmann transport equation of wave number density is introduced to model the hydrodynamic non-equilibrium effects related to the wave creation, merging and splitting processes, characteristic of developing annular two-phase flows (due to e.g., inlet effect, phase change, geometrical change or transient). Finally, the base film mass and wave number density sink and source rates are modeled using a relaxation time approximation. The new model is motivated and fully documented in this paper and has been implemented in the latest version of the transient sub-channel analysis code MEFISTO-T. While the proposed model framework is generic for coherent disturbance waves, the required wave characteristic correlations are specifically developed and calibrated using high pressure steam/water experiments under equilibrium conditions relevant of Boiling Water Reactor operation. The model relaxation times are then estimated by comparing the model predictions against measured wave parameters downstream various flow perturbations (evaporation and film suction), along the channel recovery length toward equilibrium. For all considered experiments, the model predicts the averaged wave and base film parameters typically within +/-20% and is able to capture the axial development of disturbance wave characteristics. The consideration of non-equilibrium effects is found fundamental to the accurate simulation of axially developing annular two-phase flows.

On turbulence and interfacial momentum transfer in dispersed gas-liquid flows: Contribution of bubbly flow experiments under microgravity conditions

The major focus of the present work is to develop an adequate closure model for the turbulent contribution of the interfacial momentum transfer term in turbulent bubbly flow. For this purpose, numerical simulations have been conducted on bubbly pipe flows under microgravity conditions. With no buoyancy effect, the average interfacial forces are negligible due to the small interphase relative motion. In these conditions, the distribution and the dynamics of bubbles are mainly controlled by the turbulence effects. Based on a phenomenological approach, a new closure for the turbulent interfacial momentum transfer is developed within Eulerian two-fluid modelling based on the averaging of the added mass force. The turbulent terms thus obtained comprises a non-linear term and a convective acceleration term associated with the drift velocity. The two-fluid model with the proposed interfacial momentum transfer closure and an original three-equation turbulence model for bubbly flows has been implemented in a 3D CFD code and applied to pipe bubbly flow under microgravity conditions. When compared to conventional two-fluid closures, the turbulent contribution of the added mass force proved to be a relevant closure that provides a substantial improvement in predicting the void fraction distribution and the bubbles’ dynamics.

Numerical characterization of thermalhydraulics of subcooled flow boiling through the annular core of a test facility

Presence of thermal nonequilibrium inside the vertical boiling channels can significantly influence the thermalhydraulic characteristics of BWRs. The nature of thermal interactions across interfaces is susceptible to numerous operational factors. Present study reports a comprehensive numerical investigation of subcooled boiling in a vertical annulus with heated outer wall during upflow of subcooled water. Separate conservation equations are solved for both liquid and vapor phases, coupled with wall heat flux partitioning approach and relevant closure relations. Developed computational framework is validated using experimental data from literature and employed for subsequent appraisal of one heated channel of the PCNCTF test facility. Three important transition locations are identified along the heated surface. The model efficiently emulates first vapor generation at ONB and appreciable vapor generation beyond OSV, along with gradual thickening of superheated liquid layer and penetration of vapor towards the unheated wall. Saturated boiling initiates after disappearing of convective heat flux, with a peak in quenching contribution. Appearance of actual boiling boundary is significantly delayed due to subcooled boiling, occasionally continuing the entire phase-change process in subcooled mode. Effect of heat flux, mass flux and pressure is explored on thermal characteristics and wall shear stress profiles.

Miniaturized Forced Degradation of Therapeutic Proteins and ADCs by Agitation-Induced Aggregation Using Orbital Shaking of Microplates

Microplate-based formulation screening is a powerful approach to identify stabilizing excipients for therapeutic proteins while reducing material requirements. However, this approach is sometimes not representative of studies conducted in relevant container closures. The present study aimed to identify critical parameters for a microplate-based orbital shaking method to screen biotherapeutic formulations by agitation-induced aggregation. For this purpose, an in-depth methodological study was conducted using different shakers, microplates, and plate seals. Aggregation was monitored by size exclusion chromatography, turbidity, and backgrounded membrane imaging. Both shaker quality and liquid-seal contact had substantial impacts on aggregation during shaking and resulted in non-uniform sample treatment when parameters were not suitably selected. The well volume to fill volume ratio (Vwell/Vfill) was identified as an useful parameter for achieving comparable aggregation levels between different microplate formats. An optimized method (2400 rpm [ac 95 m/s2], Vfill 60-100 µL [Vwell/Vfill 6-3.6], 24 h, RT, heat-sealed) allowed for uniform sample treatment independent of surface tension and good agreement with vial shaking results. This study provides valuable guidance for miniaturization of shaking stress studies in biopharmaceutical drug development, facilitating method transfer and comparability between laboratories.

Algorithmic definitions for KLM-style defeasible disjunctive Datalog

Datalog is a declarative logic programming language that uses classical logical reasoning as its basic form of reasoning. Defeasible reasoning is a form of non-classical reasoning that is able to deal with exceptions to general assertions in a formal manner. The KLM approach to defeasible reasoning is an axiomatic approach based on the concept of plausible inference. Since Datalog uses classical reasoning, it is currently not able to handle defeasible implications and exceptions. We aim to extend the expressivity of Datalog by incorporating KLM-style defeasible reasoning into classical Datalog. We present a systematic approach for extending the KLM properties and a well-known form of defeasible entailment: Rational Closure. We conclude by exploring Datalog extensions of less conservative forms of defeasible entailment: Relevant and Lexicographic Closure. We provide algorithmic definitions for these forms of defeasible entailment and prove that the definitions are LM-rational.

A reconstruction of multipreference closure

The paper describes a preferential approach for dealing with exceptions in KLM preferential logics, based on the rational closure. It is well known that rational closure does not allow an independent handling of inheritance of different defeasible properties of concepts. In this work, we consider an alternative closure construction, called Multi Preference closure (MP-closure), which has been first considered for reasoning with exceptions in DLs. We reconstruct the notion of MP-closure in the propositional case and show that it is a natural (weaker) variant of Lehmann's lexicographic closure, which appears to be too bold in some cases. The MP-closure defines a preferential consequence relation that, although weaker than lexicographic closure, is stronger than Relevant Closure.

Ex vivo-expanded highly pure ABCB5+ mesenchymal stromal cells as Good Manufacturing Practice-compliant autologous advanced therapy medicinal product for clinical use: process validation and first in-human data

Background aimMesenchymal stromal cells (MSCs) hold promise for the treatment of tissue damage and injury. However, MSCs comprise multiple subpopulations with diverse properties, which could explain inconsistent therapeutic outcomes seen among therapeutic attempts. Recently, the adenosine triphosphate-binding cassette transporter ABCB5 has been shown to identify a novel dermal immunomodulatory MSC subpopulation. MethodsThe authors have established a validated Good Manufacturing Practice (GMP)-compliant expansion and manufacturing process by which ABCB5+ MSCs can be isolated from skin tissue and processed to generate a highly functional homogeneous cell population manufactured as an advanced therapy medicinal product (ATMP). This product has been approved by the German competent regulatory authority to be tested in a clinical trial to treat therapy-resistant chronic venous ulcers. ResultsAs of now, 12 wounds in nine patients have been treated with 5 × 105 autologous ABCB5+ MSCs per cm2 wound area, eliciting a median wound size reduction of 63% (range, 32–100%) at 12 weeks and early relief of pain. ConclusionsThe authors describe here their GMP- and European Pharmacopoeia-compliant production and quality control process, report on a pre-clinical dose selection study and present the first in-human results. Together, these data substantiate the idea that ABCB5+ MSCs manufactured as ATMPs could deliver a clinically relevant wound closure strategy for patients with chronic therapy-resistant wounds.

A Lightweight Defeasible Description Logic in Depth

In this thesis we study KLM-style rational reasoning in defeasible Description Logics. We illustrate that many recent approaches to derive consequences under Rational Closure (and its stronger variants, lexicographic and relevant closure) suffer the fatal drawback of neglecting defeasible information in quantified concepts. We propose novel model-theoretic semantics that are able to derive the missing entailments in two differently strong flavours. Our solution introduces a preference relation to distinguish sets of models in terms of their typicality (amount of defeasible information derivable for quantified concepts). The semantics defined through the most typical (most preferred) sets of models are proven superior to previous approaches in that their entailments properly extend previously derivable consequences, in particular, allowing to derive defeasible consequences for quantified concepts. The dissertation concludes with an algorithmic characterisation of this uniform maximisation of typicality, which accompanies our investigation of the computational complexity for deriving consequences under these new semantics.

Closed without boundaries

The paper critically discusses two prominent arguments against closure principles for knowledge. The first one is the “argument from aggregation”, claiming that closure under conjunction has the consequence that, if one individually knows i premises, one also knows their i-fold conjunction—yet, every one of the premises might exhibit interesting positive epistemic properties while the i-fold conjunction might fail to do so. The second one is the “argument from concatenation”, claiming that closure under entailment has the consequence that, if one knows a premise, one also knows each of its remote consequences one arrives at—yet, again, the premise might exhibit interesting positive epistemic properties while some of its remote consequences might fail to do so. The paper firstly observes that the ways in which these two arguments try to establish that the relevant closure principle has the relevant problematic consequence are strikingly similar. They both crucially involve showing that, given the features of the case, the relevant closure principle acts in effect as a soritical principle, which is in turn assumed to lead validly to the relevant problematic consequence. There are however nontransitive logics of vagueness (“tolerant logics”, developed elsewhere by the author) where soritical principles do not have any problematic consequence. Assuming that one of these logics is the correct logic of vagueness, the paper secondly observes that both arguments describe situations where knowledge is arguably vague in the relevant respects, so that a tolerant logic should be used in reasoning about it, with the effect that the relevant soritical principle no longer validly leads to the relevant problematic consequence. This shows an interesting respect in which the gap between validity and good inference that arguably arises in a transitive framework can be bridged in a tolerant one, thereby approximating better certain features of our epistemic lives as finite subjects. Moreover, even for those who do not subscribe to tolerant logics, the paper’s two observations jointly indicate that, for all the arguments from aggregation and concatenation show, the status of the relevant closure principles should be no worse than that assigned by one’s favoured theory of vagueness to soritical principles, which only rarely is plain falsity and can indeed get arbitrarily close to full truth.

Evaluation of Hydrodynamic Closures for Bubbly Regime CFD Simulations in Developing Pipe Flow

AbstractThe effect of interfacial forces and relevant closures, particularly the lift and wall lubrication forces, on the predictions of Eulerian‐Eulerian computational fluid dynamics simulations of bubbly flows was studied. The test case under study was a developing turbulent bubbly pipe flow, simulated by using OpenFOAM. The results show that the geometric approach to consider the wall effect leads to better agreement than a standard relation assuming asymmetric drainage around the bubble near the wall. Furthermore, the results verify the need for employing negative lift coefficients in cases with large bubbles. A sensitivity analysis on the lift coefficient highlighted the importance of investigating spatially developing flows to draw general conclusions on the applicability of closure relations.

Reasoning in the Defeasible Description Logic —computing standard inferences under rational and relevant semantics

Defeasible Description Logics (DDLs) extend Description Logics with defeasible concept inclusions. Reasoning in DDLs often employs rational closure according to the (propositional) KLM postulates. A well-known approach to lift this closure to DDLs is by so-called materialisation. Previously investigated algorithms for materialisation-based reasoning employ reductions to classical reasoning using all Boolean connectors. As a first result in this paper, we present a materialisation-based algorithm for the sub-Boolean DDL ▪, using a reduction to reasoning in classical ▪, rendering materialisation-based defeasible reasoning tractable.The main contribution of this article is a kind of canonical model construction, which can be used to decide defeasible subsumption and instance queries in ▪ under rational and the stronger relevant entailment. Our so-called typicality models can reproduce the entailments obtained from materialisation-based rational and relevant closure and, more importantly, obtain stronger versions of rational and relevant entailment. These do not suffer from neglecting defeasible information for concepts appearing nested inside quantifications, which all materialisation-based approaches do. We also show the computational complexity of defeasible subsumption and instance checking in our stronger rational and relevant semantics.

Long crack growth and crack closure in high strength nodular cast iron

In the context of wind turbines, highly stressed structural components are often made of EN-GJS-700-2. This high strength nodular cast iron grade is characterized by an almost purely pearlitic matrix resulting in a comparatively low toughness. Therefore and due to inevitable casting defects, a fracture mechanical strength assessment, additionally to a conventional one, is often required. However, it lacks a detailed characterisation of EN-GJS-700-2 in terms of fracture mechanical material parameters. Thus, the objective of this study was to derive a comprehensive description of long crack growth for this cast iron grade.For this purpose, profound experiments were performed on raw material taken from a real planet carrier. Crack growth was analysed under varying loading conditions whereby the impact of the stress ratio and the maximum stress intensity factor was of special interest. The threshold behaviour was described in terms of two threshold values. Relevant crack closure mechanisms were analysed in detail: plasticity, oxidation and surface roughness. The latter one was identified as the most dominating mechanism. Three different approaches to describe crack closure were derived. Its integration into a crack growth law yielded a uniform description in terms of an effective stress intensity factor. To describe crack growth in a less complex way, two other crack growth laws, based on a two-parameter approach respectively on the maximum stress intensity factor, were derived.

Platelet-rich fibrin, a physiological concentrate in the management of buccal dehiscence of implant – A case report

IntroductionSuccessful implant dentistry is based on proper selection of patients, careful surgery, preplanned restorations, and postoperative and supportive care. Although implant therapy is highly successful and predictable, it is not without early and/or late complications. Placement of dental implants in narrow or atrophic edentulous ridges often leads to complications, such as dehiscence and fenestration.1 Case reportThis case report presents the successful management of buccal dehiscence of single-staged implant for replacement of left central incisor with the platelet-rich fibrin (PRF) and autogenous bone graft material. The initial mobility was completely resolved after 12 weeks and final restoration was given to patient. DiscussionThe treatment for dehiscence requires the use of various regenerative procedures but PRF belongs to a new generation of platelet concentrates geared to simplify preparation without biochemical blood handling.2 Adjunctive implantation of PRF does appear to significantly improve the healing response, which has resulted in rapid, clinically relevant bone closure of dental implant dehiscence defect in the present case.

On squares of representations of compact Lie algebras

We study how tensor products of representations decompose when restricted from a compact Lie algebra to one of its subalgebras. In particular, we are interested in tensor squares which are tensor products of a representation with itself. We show in a classification-free manner that the sum of multiplicities and the sum of squares of multiplicities in the corresponding decomposition of a tensor square into irreducible representations has to strictly grow when restricted from a compact semisimple Lie algebra to a proper subalgebra. For this purpose, relevant details on tensor products of representations are compiled from the literature. Since the sum of squares of multiplicities is equal to the dimension of the commutant of the tensor-square representation, it can be determined by linear-algebra computations in a scenario where an a priori unknown Lie algebra is given by a set of generators which might not be a linear basis. Hence, our results offer a test to decide if a subalgebra of a compact semisimple Lie algebra is a proper one without calculating the relevant Lie closures, which can be naturally applied in the field of controlled quantum systems.

Evaluation of drag models for cocurrent and countercurrent gas–solid flows

Gas–solid systems, whether cocurrent or countercurrent, manifest meso-scale heterogeneity to some extent. However, most of the previous modelling efforts, including the study of the effects of meso-scale structures as well as relevant drag closures, are mainly focused on cocurrent up riser flows, leaving cocurrent down and countercurrent systems less explored. In this work, by extending drift flux analysis and experimental validation for cocurrent down and countercurrent flow systems, we show that the most commonly used homogeneous drag models may be successful in a certain range of operating conditions, especially with fine-grid resolution. Fine-grid resolution is indeed helpful for reliable simulation of coexisting states, by predicting concave slip velocity curves. By comparison, the energy minimization multiscale (EMMS) drag model allows the use of much coarser grid resolution and better prediction over wider range of operating conditions. Its predictability of the overall slip velocity as well as the drift flux is nearly grid independent over the entire range of voidage. This fact leads us to the obvious advantage of saving computational time.

High on‐treatment platelet reactivity on commonly prescribed antiplatelet agents following transient ischaemic attack or ischaemic stroke: results from the Trinity Antiplatelet Responsiveness (TRAP) study

The prevalence of ex vivo 'high on-treatment platelet reactivity' (HTPR) to antiplatelet regimens in patients with ischaemic cerebrovascular disease (CVD) is uncertain. HTPR was assessed with PFA-100 collagen-epinephrine (C-EPI) and collagen-ADP (C-ADP) cartridges. Platelet activation (CD62P, CD63 and leucocyte-platelet complex formation) was assessed with whole-blood flow cytometry. Patients were assessed at baseline [≤ 4 weeks of transient ischaemic attack (TIA) or ischaemic stroke], and at 14 days and ≥ 90 days after changing treatment from (i) no medication to aspirin monotherapy (N = 26) or (ii) aspirin to clopidogrel monotherapy (N = 22). HTPR was defined in a novel, 'longitudinal fashion' as failure to prolong relevant closure times compared with the patient's 'baseline value' before he/she underwent an antiplatelet change by more than twice the coefficient of variation of the assay. (i) C-EPI closure times increased at 14 days and 90 days after commencing aspirin (P = 0.002); 24% at 14 days and 18% at 90 days demonstrated HTPR on aspirin. (ii) C-ADP closure times increased at 14 days (P = 0.001) but not 90 days (P = 0.09) after changing from aspirin to clopidogrel; 41% at 14 days, and 35% at 90 days demonstrated HTPR on clopidogrel. Platelet activation was unaffected by aspirin (P = 0.09). The percentage neutrophil-platelet complexes decreased at 14 days (P = 0.02), but this reduction was not maintained 90 days after changing to clopidogrel (P = 0.3). No patient had a recurrent vascular event during prospective follow-up. Longitudinal definitions of HTPR in patients with ischaemic CVD who are undergoing a change in antiplatelet therapy have the potential to provide more clinically meaningful information than traditional 'cross-sectional definitions' of HTPR which are usually based on the comparison of patients' values with those in healthy controls. Using our novel, longitudinal definition of HTPR, the PFA-100 could be used to monitor ex vivo responsiveness to aspirin, and larger, prospective studies are warranted to assess the clinical predictive value of this and other platelet function tests in patients with ischaemic CVD.

A numerical technique for analysis of transient two-phase flow in a vertical tube using the Drift Flux Model

► A numerical technique for transient two-phase flow in a vertical channel using the Drift Flux Model is presented. ► The proposed model was validated for wide range two-phase flow parameters. ► Good agreement between the predicted void fraction, RELAP5 code and the experimental data was obtained. ► The analysis lead to a better understanding of the basic mechanism of sub-cooled flow boiling. ► It was concluded that the model predicts the void fraction in two phase flow with sufficient accuracy. This paper presents a numerical solution of one-dimensional transient two-phase flow in a vertical channel using the Drift Flux Model (DFM). The DFM treats the two phases as a mixture, but allows slippage between the gas and the liquid phase. The DFM was used for the calculation of velocity and fraction of each phase, combined with the most relevant closure relationships models for condensation, wall evaporation, and phasic velocities. The solution of the three conservation equations for the mixture and a continuity equation for the gas phases is obtained by a semi-implicit numerical method. A finite volume method is used to discretize the governing equations on a staggered grid in the computational domain. Satisfactory agreement is shown between predicted void fraction, RELAP5 code and available experimental data under both transient and steady state conditions. Numerical solution was also obtained for a wide two-phase flow conditions: system pressure, surface heat flux, mass flow rate and inlet sub-cooling to check the model ability to predict void fraction accurately. It is concluded, therefore, that the DFM is able to predict void fraction in subcooled flow boiling with sufficient accuracy. For pressures lower than 30 bars, the DFM overestimated the void fraction in comparison with the experimental data by about 15%. The model requires less computational power to simulate than other approaches and has no limitations on the nodalization process for numerical stability. It is therefore expected that development of presented model will be useful for the assessment of experimental data, as well as performing pre-test numerical experimentation.

A GLOBAL TURBULENCE MODEL FOR NEUTRINO-DRIVEN CONVECTION IN CORE-COLLAPSE SUPERNOVAE

Simulations of core-collapse supernovae (CCSNe) result in successful explosions once the neutrino luminosity exceeds a critical curve, and recent simulations indicate that turbulence further enables explosion by reducing this critical neutrino luminosity. We propose a theoretical framework to derive this result and take the first steps by deriving the governing mean-field equations. Using Reynolds decomposition, we decompose flow variables into background and turbulent flows and derive self-consistent averaged equations for their evolution. As basic requirements for the CCSN problem, these equations naturally incorporate steady-state accretion, neutrino heating and cooling, non-zero entropy gradients, and turbulence terms associated with buoyant driving, redistribution, and dissipation. Furthermore, analysis of two-dimensional (2D) CCSN simulations validate these Reynolds-averaged equations, and we show that the physics of turbulence entirely accounts for the differences between 1D and 2D CCSN simulations. As a prelude to deriving the reduction in the critical luminosity, we identify the turbulent terms that most influence the conditions for explosion. Generically, turbulence equations require closure models, but these closure models depend upon the macroscopic properties of the flow. To derive a closure model that is appropriate for CCSNe, we cull the literature for relevant closure models and compare each with 2D simulations. These models employ local closure approximations and fail to reproduce the global properties of neutrino-driven turbulence. Motivated by the generic failure of these local models, we propose an original model for turbulence which incorporates global properties of the flow. This global model accurately reproduces the turbulence profiles and evolution of 2D CCSN simulations.