Βελτιστοποίηση παραμέτρων ελέγχου ανεμογεννητριών με χρήση υποκατάστατων μοντέλων

Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Παραγωγή και Διαχείρηση Ενέργειας

Truncation Error-Based Anisotropic pp-Adaptation for Unsteady Flows for High-Order Discontinuous Galerkin Methods

In this work, we extend the $\tau$-estimation method to unsteady problems and use it to adapt the polynomial degree for high-order discontinuous Galerkin simulations of unsteady flows. The adaptation is local and anisotropic and allows capturing relevant unsteady flow features while enhancing the accuracy of time evolving functionals (e.g., lift, drag). To achieve an efficient and unsteady truncation error-based $p$-adaptation scheme, we first revisit the definition of the truncation error, studying the effect of the treatment of the mass matrix arising from the temporal term. Secondly, we extend the $\tau$-estimation strategy to unsteady problems. Finally, we present and compare two adaptation strategies for unsteady problems: the dynamic and static $p$-adaptation methods. In the first one (dynamic) the error is measured periodically during a simulation and the polynomial degree is adapted immediately after every estimation procedure. In the second one (static) the error is also measured periodically, but only one $p$-adaptation process is performed after several estimation stages, using a combination of the periodic error measures. The static $p$-adaptation strategy is suitable for time-periodic flows, while the dynamic one can be generalized to any flow evolution. We consider two test cases to evaluate the efficiency of the proposed $p$-adaptation strategies. The first one considers the compressible Euler equations to simulate the advection of a density pulse. The second one solves the compressible Navier-Stokes equations to simulate the flow around a cylinder at Re=100. The local and anisotropic adaptation enables significant reductions in the number of degrees of freedom with respect to uniform refinement, leading to speed-ups of up to $\times4.5$ for the Euler test case and $\times2.2$ for the Navier-Stokes test case

First Report for Pathogenity of Cydia Pomonella Granulovirus and Helicoverpa Armigera Nucleopolyhedrovirus to Indian Meal Moth Plodia Interpunctella Hϋbner (Lepidoptera: Pyralidae) in Vitro

The purpose of this study was to examine the for the first time the effect of Cydia pomonella granulovirus and Helicoverpa armigera nucleopolyhedrovirus on the larvae of the Lepidopteran Plodia interpunctella. L3 larvae were tested to see whether they were influenced by the infection of the two entomopathogenic viruses Cydia pomonella granulovirus and Helicoverpa armigera nucleopolyhedrovirus. The experiment lasted seven days. The results showed that the effect of the two Baculoviruses was statistically important in relation to the control. The effect of the virus H. armigera nucleopolyhedrovirus was greater than the effect of the virus C. pomonella granulovirus, and this led us to the assumption that the use of entomopathogenic viruses can play an important role in controlling P. interpunctella larvae. The recorded mortality after 7 days was for larvae treated with C. pomonella granulovirus 33.3 to 86.7%, with H. armigera nucleopolyhedrovirus 53.3 to 93.3% and control mortality was 0.7%. This information may appear particularly useful in the future control of the insect’s populations in the warehouse

Retrospective, controlled observational case study of patients with central retinal vein occlusion and initially low visual acuity treated with an intravitreal dexamethasone implant

Background Patients with initially low visual acuity were excluded from the therapy approval studies for retinal vein occlusion. But up to 28 % of patients presenting with central retinal vein occlusion have a baseline BCVA of less than 34 ETDRS letters (0.1). The purpose of our study was to assess visual acuity and central retinal thickness in patients suffering from central retinal vein occlusion and low visual acuity (<0.1) in comparison to patients with visual acuity (≥0.1) treated with Dexamethasone implant 0.7 mg for macular edema. Methods Retrospective, controlled observational case study of 30 eyes with macular edema secondary to central retinal vein occlusion, which were treated with a dexamethasone implantation. Visual acuity, central retinal thickness and intraocular pressure were measured monthly. Analyses were performed separately for eyes with visual acuity <0.1 and ≥0.1. Results Two months post intervention, visual acuity improved only marginally from 0.05 to 0.07 (1 month; p = 0,065) and to 0.08 (2 months; p = 0,2) in patients with low visual acuity as compared to patients with visual acuity ≥0.1 with an improvement from 0.33 to 0.47 (1 month; p = 0,005) and to 0.49 (2 months; p = 0,003). The central retinal thickness, however, was reduced in both groups, falling from 694 to 344 μm (1 month; p = 0.003,) to 361 μm (2 months; p = 0,002) and to 415 μm (3 months; p = 0,004) in the low visual acuity group and from 634 to 315 μm (1 month; p < 0,001) and to 343 μm (2 months; p = 0,001) in the visual acuity group ≥0.1. Absence of visual acuity improvement was related to macular ischemia. Conclusions In patients with central retinal vein occlusion and initially low visual acuity, a dexamethasone implantation can lead to an important reduction of central retinal thickness but may be of limited use to increase visual acuity

Clot characterization by multidisciplinary approach: biochemical and imaging parameters in a hypocoagulative setting. A pilot study.

Background: Clot characterization is, to the present days, a multimodal approach: scanning the clot by electron microscopy (SEM) is helpful for the visualization of fibrin structure along with laboratory parameters such as the clot waveform analysis (CWA) and thrombin generation in different settings of clot abnormalities. This study aimed to assess whether the coagulative parameters were consistent with the clot images texture acquired by SEM, and therefore to propose a more generalist and integrative approach to clots classification.Design and Methods: In this pilot study, the examined population consists of eight healthy subjects, seven patients affected by Acquired Hemophilia A (AHA) and seven patients treated with Vitamin K Antagonists (VKAs), similar for age and gender. We studied the velocity and acceleration (1st and 2nd derivative of the aPTT) of clot formation (CWA), the thrombin generation, and the clots' scanning by SEM. Images acquired with SEM were then analyzed with the MATLAB software with the "Texture Analysis" methods to perform classification. Among the various texture parameters, we reported Contrast and Energy.Results: Significant differences among healthy subjects, patients with AHA and those treated with VKAs were detected for the coagulative parameters. We found no differences between VKAs and AHA patients. Contrast and energy highlighted a significant difference among the three groups in agreement with the laboratory's parameters. We found no significant differences between VKAs and AHA patients.Conclusions: The use of SEM, CWA and thrombin generation parameters may be a starting point for studies aimed to demonstrate the general characteristics of clot formation in different clinical conditions with a multiparametric approach

Retinal Involvement in a Patient with Cerebral Manifestation of Chronic Graft-Versus-Host-Disease

Background: We report a 35-year-old female patient with cerebral manifestations of chronic graft-versus-host disease (cGvHD) and putative retinal involvement after allogeneic peripheral blood stem cell transplantation (alloHSCT). Patient and Methods: The patient experienced recurrent episodes of fever and encephalitic signs 7 months after alloHSCT during taper of immunosuppression (IS). Results: Cerebral magnetic resonance imaging (MRI) showed non-gadolinium-enhancing confluent periventricular lesions and cerebrospinal fluid inflammation. After exclusion of infectious causes, treatment with steroids and antiepileptics improved cognitive deficits. Steroid reduction provoked a relapse responding to IS. 2 years later, she complained of right-sided blurred vision and floaters; both eyes showed whitish circumscribed retinal infiltrations, cellular infiltration of the vitreous and mild bilateral optic disc edema. Oncological and neurological work-up ruled out infectious diseases and other GvHD manifestations. Symptoms and signs resolved under continued systemic IS, leaving pigmented retinal scars. After IS withdrawal, classical cutaneous cGvHD developed, resolving on systemic IS. 94 months after transplantation, she is doing well. Conclusion: To our knowledge, this is the first observation of retinal involvement of cerebral cGvHD manifestations with retinal infiltrations documented in the absence of other causes and in parallel to periventricular lesions in cerebral MRI. Based on bone marrow histology, we discuss a small vessel pathophysiology of cGvHD

Chelator-free/chelator-mediated radiolabeling of colloidally stabilized iron oxide nanoparticles for biomedical imaging

The aim of this study was to develop a bioimaging probe based on magnetic iron oxide nanoparticles (MIONs) surface functionalized with the copolymer (p(MAA-g-EGMA)), which were radiolabeled with the positron emitter Gallium-68. The synthesis of the hybrid MIONs was realized by hydrolytic condensation of a single ferrous precursor in the presence of the copolymer. The synthesized MagP MIONs displayed an average D-h of 87 nm, suitable for passive targeting of cancerous tissues through the enhanced permeation and retention (EPR) effect after intravenous administration, while their particularly high magnetic content ascribes strong magnetic properties to the colloids. Two different approaches were explored to develop MIONs radiolabeled with Ga-68: the chelator-mediated approach, where the chelating agent NODAGA-NHS was conjugated onto the MIONs (MagP-NODAGA) to form a chelate complex with Ga-68, and the chelator-free approach, where Ga-68 was directly incorporated onto the MIONs (MagP). Both groups of NPs showed highly efficient radiolabeling with Ga-68, forming constructs which were stable with time, and in the presence of PBS and human serum. Ex vivo biodistribution studies of [Ga-68]Ga- MIONs showed high accumulation in the mononuclear phagocyte system (MPS) organs and satisfactory blood retention with time. In vivo PET imaging with [Ga-68]Ga-MagP MIONs was in accordance with the ex vivo biodistribution results. Finally, the MIONs showed low toxicity against 4T1 breast cancer cells. These detailed studies established that [Ga-68]Ga- MIONs exhibit potential for application as tracers for early cancer detection.Web of Science117art. no. 167