8 research outputs found
Long-term bio-functional performance of a novel, self-positioning balloon expandable transcatheter biological aortic valve system in the ovine aortic banding model
Background: The aim of the study was to evaluate bio-functionality of a novel, proprietary balloon-expandable biological transcatheter aortic valve implantation (TAVI) system (InFlow, CardValve Consortium, Poland) in an ovine model of aortic banding.
Methods: Surgical ascending aorta banding was created in 21 sheep. Two weeks later, 18 biological valves were implanted within the model using 15–16 F InFlow TAVI systems and carotid cut-down approach. Follow-up transthoracic echocardiography was performed at 30, 90, and 180-day. At designated time, animals were euthanized and valves harvested for analysis.
Results: All sheep survived the banding procedure. There were 4 (22%) procedure related deaths within a 7-day period. During the observation an additional 2 sheep died. In one, the valve dislocated after the procedure — the animal was excluded. Two animals completed 30-day follow up, five 90-day follow-up and four terminal follow-up of 180 days. Valves examined via transesophageal echocardiography showed proper hemodynamic parameters without evidence of structural valve deterioration. The maximum and average flow gradients at 180 days were 31.4 (23.3–37.7) and 17.5 (13.1–20.2) mmHg, respectively. There was one case of moderate insufficiency and no case of perivalvular leaks. By histopathology, there were no inflammation, thrombosis, nor calcifications in any tested valves at long-term follow-up. Neointimal coverage of stent struts increased with time from basal part in “early” groups to nearly 3/4 of stent length in the 180-day group. The pannus tissue showed maturation that increased with time with no stenotic “collar” visible in orthotopically implanted valves.
Conclusions: The study showed good hemodynamic performance, durability and biocompatibility of the novel biological THV
Scalone uklady elektroniki odczytu dla matryc detektorów półprzewodnikowych o dużej liczbie atomowej Z rozprawa doktorska /
Praca doktorska. Akademia Górniczo-Hutnicza im. Stanisława Staszica (Kraków), 2011.Zawiera bibliogr.Dostępna także w wersji drukowanej.Tryb dostępu: Internet.Detektory promieniowania X, oddziaływanie z materią, opis zjawisk fizycznych, przekroje czynne, długość absorpcji dla różnych materiałów, mechanizm generacji ładunku w detektorze, średnia energia potrzebna do generacji pary elektron-dziura, współczynnik Fano, przebieg czasowy impulsu w detektorze, twierdzenie Ramo, detektory pozycyjne, paskowe jednostronne, dwustronne, mozaikowe, dryfowe, typu integrującego, CCD, monolityczne aktywne piksele, model elektryczny detektora paskowego, dobór materiału detektora promieniowania X, przegląd istniejących rozwiązań elektroniki odczytowej, układy odczytowe dla detektorów paskowych, projektowane przez BNL, układ KW03, RENA 3, DEDIX, CERN-DxCTA, dla detektorów mozaikowych, Medipix 2, H04, XPAD, wielokanałowy układ scalony w technologii submikronowej dla potrzeb detektorów o wysokiej liczbie atomowej Z, architektura układu, wzmacniacz ładunkowy, układ równoważenia par biegun-zero, analiza szumów wzmacniacza ładunkowego z uwzględnieniem prądu upływu detektora, układ PZC dostosowany do pracy z detektorami typu AC, DC, układ kształtujący, przywracania poziomu zerowego, dyskryminator, pomiary układu SXDR64 z detektorami promieniowania X, pomiary testowe SXDR64 bez detektora, opis stanowiska do pomiarów z promieniowaniem X, pomiary referencyjne z detektorem krzemowym, detektor krzemowy typu AC, DC, CdTe, podsumowanie wyników pomiarowych układu SXDR64, układ SXDv2, architektura, detektor CdTe, pracujący w trybie zbierania dziur, zliczania elektronó
Hydrocode Investigations of Terminal Astroballistics Problems during the Hypothetical Future Planetary Defense System’s Space Mission
The article is devoted to the preliminary concept of the Future Planetary Defense System (FPDS) emphasizing astroballistics. This paper is intended to support international efforts to improve the planetary security of Earth. The work covers three areas of knowledge: astronautics, astrodynamics, and astroballistics. The most important part of the presented article is dynamic, contact combat modeling against small, deformable celestial bodies. For these purposes, the original, proprietary hydrocode of the free particle method (HEFPM-G) with gravity was used. The main aim of combat is to redirect potentially hazardous objects (PHOs) to orbits safe for Earth or destroy them. This concept’s first task is to find, prepare, and use dynamic three-dimensional models of the motion of celestial bodies and spacecraft or human-crewed spaceships in the solar system’s relativistic frame. The second task is to prepare the FPDS’ architecture and computer simulation space missions’ initial concepts in the internal part of the solar system. The third and main task covers simulating, using hydrocodes, and selected methods of fighting 100 m diameter rock material asteroids
Intake System Performance Stability as a Function of Flow Throttling
This paper presents a numerical analysis of the stability of the flow parameters along the intake duct of an aircraft jet turbine engine. This problem has been investigated by many research teams and was included in the literature analysis. The unstable operation of a turbojet intake system can be the consequence of many adverse factors, including an intake vortex. The investigated intake system, due to its low location to the plane of the airport, is highly susceptible to the formation of an intake vortex. The phenomenon of an intake vortex can, in the worst-case scenario, result in the surging of the turbojet, and even engine stalling. This paper presents a developed model of the forward section of an aircraft, complete with its intake duct, and the method of its discretization. The intake-system model and numerical analysis were performed in Ansys Fluent. The flow parameters adopted for numerical simulations, under specific boundary conditions, corresponded to the operating conditions of the engine cooperating with the investigated intake system. The numerical calculations were performed assuming an air-pressure rise in the end section of the engine-intake system, reflecting the reduction in the pitch angle of the inlet stator blades of the fan. As a result, the pressure distributions in a significant cross section in the intake system were obtained. The results were analyzed with the quantitative distribution of the pressure fields by applying a dimensionless potential-pressure ratio. The pressure ratio enabled a comparative analysis of the nonuniformity of the total-pressure distribution in selected cross sections of the intake system. The results were revealing in terms of growing unstable flows in the flow duct. A major conclusion drawn from the results, by testing the dimensionless potential-pressure ratio, was that, within certain limits, it was possible to improve the flow uniformity by increasing the throttling pressure
Assessment of the Possibility of Using Hemp Biomass (Cannabis Sativa L.) for Energy Purposes: A Case Study
During testing, the possibility of using hemp biomass for energy purposes was assessed. The criteria assessed were the physical and chemical properties of hemp biomass, as well as the combustion process of straw and briquettes made of it in a low-power boiler. The results were made and compared with currently applicable standards. Technical and chemical properties of hemp biomass are comparable with the best plants used for energy purposes. Studies have also shown the susceptibility of hemp biomass compaction. However, large emissions recorded during the combustion of the tested forms of biofuels from hemp straw in light of applicable standards disqualify this fuel for use in grate-type heating devices with air fed under the grate. It would be advisable to carry out research on the total costs of pellet production and their use in heating devices with a retort burner, while taking into account this biofuel’s ashes’ susceptibility of sintering
New pixel detector concept DuTiP for Belle II upgrade and the ILC with an SOI technology
International audienceBelle II detector upgrade is being discussed aiming to collect five times larger integrated luminosity of 250 ab−1. The beam background level is expected five times higher than current design, thus a new pixel vertex detector with faster readout should be developed. We have invented a new pixel detector concept DuTiP for the Belle II upgrade which can be also used for the International Linear Collider (ILC) with small modifications. To realize the DuTiP concept, an SOI technology is chosen as a baseline with a pixel size of 35μm×35μm. The DuTiP concept and its application to a monolithic pixel detector in an SOI technology are explained
International Large Detector: Interim Design Report
The ILD detector is proposed for an electron-positron collider with collision centre-of-mass energies from 90~\GeV~to about 1~\TeV. It has been developed over the last 10 years by an international team of scientists with the goal to design and eventually propose a fully integrated detector, primarily for the International Linear Collider, ILC. In this report the fundamental ideas and concepts behind the ILD detector are discussed and the technologies needed for the realisation of the detector are reviewed. The document starts with a short review of the science goals of the ILC, and how the goals can be achieved today with the detector technologies at hand. After a discussion of the ILC and the environment in which the experiment will take place, the detector is described in more detail, including the status of the development of the technologies foreseen for each subdetector. The integration of the different sub-systems into an integrated detector is discussed, as is the interface between the detector and the collider. This is followed by a concise summary of the benchmarking which has been performed in order to find an optimal balance between performance and cost. To the end the costing methodology used by ILD is presented, and an updated cost estimate for the detector is presented. The report closes with a summary of the current status and of planned future actions
The ILD detector at the ILC
The International Large Detector, ILD, is a detector concept which has been developed for the electron-positron collider ILC. The detector has been optimized for precision physics in a range of energies between 90 GeV and 1 TeV. ILD features a high precision, large volume combined silicon and gaseous tracking system, together with a high granularity calorimeter, all inside a 3.5 T solenoidal magnetic field. The paradigm of particle flow has been the guiding principle of the design of ILD. In this document the required performance of the detector, the proposed implementation and the readiness of the different technologies needed for the implementation are discussed. This is done in the framework of the ILC collider proposal, now under consideration in Japan, and includes site specific aspects needed to build and operate the detector at the proposed ILC site in Japan