Search results for "PIP"

Res sunt ut agas. Scritti per Gianna Petrone

2010

Intrakraniālo aneirismu endovaskulāra ārstēšana ar plūsmas novirzītāju stentiem

2016

Darba mērķis ir zinātniski pamatot intrakraniālu aneirismu endovaskulāru ārstēšanu ar plūsmas novadītājiem. Darba uzdevumi 1. apkopot esošos teorētiskos datu rezultātus par intrakraniālu aneirismu patoloģiju, anamnēzi un ārstēšanu, kur lietoti plūsmas novirzītāji; 2. apkopot PSKUS plūsmas novirzītāju lietošanas pieredzi intrakraniālu aneirismu ārstēšanā. 3. atrast saistību starp intrakraniālo stentu implantāciju un mātes asinsvada remodelāciju, aneirismas maisa mazināšanos. Metodes tika veikts retrospektīvs pētījums, kuram ētikas komisijas atļauju deva LU Eksperimentālās un klīniskās medicīnas institūta Zinātniskās izpētes ētikas komisija. Pētījumā tika analizēts 31 intrakraniālo aneirismu …

Autonomous Mooring towards Autonomous Maritime Navigation and Offshore Operations

2020

Bollard is a vital component of mooring system. It is the anchor point for mooring ropes to be fixed in order to secure the vessel or ship. An algorithm that translates the segmented mask of bollard output from masked R-CNN along with bounding box and associated class probability to its corresponding edge coordinate and finally to the single reference point for efficient detection and classification of bollard towards autonomous mooring is presented. At first stage, Mask R-CNN framework is trained with custom built bollard. The model obtained from the training is inferred with real data resulting in instance segment of bollard. The segmented mask obtained contains relatively large amount of…

Monitoring Mediterranean marine pollution using remote sensing and hydrodynamic modelling

2011

Human activities contaminate both coastal areas and open seas, even though impacts are different in terms of pollutants, ecosystems and recovery time. In particular, Mediterranean offshore pollution is mainly related to maritime transport of oil, accounting for 25% of the global maritime traffic and, during the last 25 years, for nearly 7% of the world oil accidents, thus causing serious biological impacts on both open sea and coastal zone habitats. This paper provides a general review of maritime pollution monitoring using integrated approaches of remote sensing and hydrodynamic modeling; focusing on the main results of the MAPRES (Marine pollution monitoring and detection by aerial survei…

Templated synthesis of a large and flexible covalent porphyrinic cage bearing orthogonal recognition sites.

2012

A large covalent cage incorporating two porphyrins attached by four long and flexible polyether chains each bearing two 3-pyridyl ligands was synthesized from a DABCO-templated olefin metathesis reaction. The X-ray structure of the cage with the DABCO coordinated inside the cavity to the two zinc(II) porphyrins reveals a highly symmetric structure.

Suzuki-Miyaura cross-coupling of arenediazonium salts catalyzed by alginate/gellan-stabilized palladium nanoparticles under aerobic conditions in wat…

2012

The use of palladium nanoparticles stabilized by natural. beads made of an alginate/gellan mixture in the Suzuki-Miyaura cross-coupling reaction of arenediazonium. tetrafluoroborates with potassium aryltrifluoroborates. (1 : 1 molar ratio) with loading as low as 0.01–0.002. mol% under aerobic, phosphine-, and base-free conditions. in water is described. The catalyst system can be reused. several times without significant loss of activity.

Cost-Benefit Analysis for Hydropower Production in Water Distribution Networks by a Pump as Turbine

2014

AbstractThe use of microhydroelectric plants in urban pipe networks, based on the combination of a pump as turbine (PAT), two regulating valves, and two pressure meters, is proposed along with simple automation rules. Its economic benefit is tested on a small pipe network, where the network geometry as well as the demand coefficient variation in time and space have been inferred from previously collected data and existing analysis. A similar analysis has been also carried out for different scenarios in which the reduction of pipe installation cost due to a diameter reduction is compared with the increased benefit in energy production. The case study shows that a small increment of the pipe …

Preoperative Planning for Guidewires Employing Shape-Regularized Segmentation and Optimized Trajectories

2019

Upcoming robotic interventions for endovascular procedures can significantly reduce the high radiation exposure currently endured by surgeons. Robotically driven guidewires replace manual insertion and leave the surgeon the task of planning optimal trajectories based on segmentation of associated risk structures. However, such a pipeline brings new challenges. While Deep learning based segmentation such as U-Net can achieve outstanding Dice scores, it fails to provide suitable results for trajectory planning in annotation scarce environments. We propose a preoperative pipeline featuring a shape regularized U-Net that extracts coherent anatomies from pixelwise predictions. It uses Rapidly-ex…

Loop seals in circulating fluidized beds – Review and parametric studies using CPFD simulation

2020

Abstract Loop seal is a robust particle recycling technique used in circulating fluidized bed (CFB) reactors. The rate and the location of the loop seal aeration exert a significant impact on the rate of particle circulation (GS). The standpipe balances the cumulative pressure drop across the rest of the CFB by adjusting its particle height or gas-particle slip velocity. Higher fraction of the loop seal aeration naturally flows down to riser. Increased pressure drop in the standpipe results in high rate of particle circulation. Computational-particle-fluid-dynamic (CPFD) code is customized for multiphase flow modelling. The inbuilt tool of “BC connectors” was incorporated to downsize a CFB …

Simplified Procedure to Evaluate Head Losses in Drip Irrigation Laterals

2005

The lateral lines of a drip irrigation system consist of pressurized pipelines with inline or online emitters. Proper hydraulic design of drip laterals usually requires the accurate evaluation of the total head losses, represented by friction losses along the pipe and the emitters, and local losses due to the emitter connections. This paper extends the local loss evaluation procedure, previously obtained for coextruded laterals, on the basis of new experiments. In addition, a simplified procedure was proposed based on the constant outlet discharge assumption for a quick evaluation of total head losses in drip irrigation lines, taking into account the total local loss due to the emitter conn…