Search results for " Stability"
showing 10 items of 1355 documents
Stabilność polityczna i personalna władz w warunkach alternacji i ciągłości rządów
2017
Celem rozdziału jest analiza stabilności polskiej sceny politycznej w wymiarze politycznym i personalnym. Przejścia i rozłamy w klubach parlamentarnych oraz zmiany w ramach gabinetów rządowych w trakcie V, VI i VII kadencji Sejmu poddane zostały analizie ilościowej i jakościowej. Pozwoliła ona sformułować wnioski o stabilności struktur władzy ustawodawczej i wykonawczej. Analizie poddano okres 10 lat, obejmujący trzy kadencje Sejmu oraz pięć gabinetów rządowych. Głównym problemem badawczym jest określenie, na ile zmiany w politycznym i personalnym składzie organów władzy wykonawczej i ustawodawczej odzwierciedlają polityczną stabilność całego systemu politycznego. Pod uwagę wzięto trzy kade…
On the high-pressure phase stability and elastic properties ofβ-titanium alloys
2017
We have studied the compressibility and stability of different β-titanium alloys at high pressure, including binary Ti–Mo, Ti–24Nb–4Zr–8Sn (Ti2448) and Ti–36Nb–2Ta–0.3O (gum metal). We observed stability of the β phase in these alloys to 40 GPa, well into the ω phase region in the P–T diagram of pure titanium. Gum metal was pressurised above 70 GPa and forms a phase with a crystal structure similar to the η phase of pure Ti. The bulk moduli determined for the different alloys range from 97 ± 3 GPa (Ti2448) to 124 ± 6 GPa (Ti–16.8Mo–0.13O).
Assessment of Physical and Chemical Stability of Different Magnesium Compounds in Tablets
2020
Modern lifestyle, excessive chemicalization of agricultural products, excessive processing and refining of food, cause a decrease in daily intake of magnesium, cation with an extremely important role in prevention and treatment of many diseases. As a result, there arises the need for extra magnesium intake in the form of dietary supplements. In this study were evaluated the physical and chemical stability of magnesium-containing tablets, depending on the active compound and the excipients used. Magnesium tablets in the form of orotate, lactate, citrate, oxide and hydroxide were taken into study and physical and chemical stability were observed over the validity period, at 6 and at 12 month…
The Interconnecting Hairpin Extension "Arm": An Essential Allosteric Element of Phytochrome Activity
2023
In red-light sensing phytochromes, isomerization of the bilin chromophore triggers structural and dynamic changes across multiple domains, ultimately leading to control of the output module (OPM) activity. In between, a hairpin structure, "arm", extends from an interconnecting domain to the chromophore region. Here, by removing this protein segment in a bacteriophytochrome from Deinococcus radiodurans (DrBphP), we show that the arm is crucial for signal transduction. Crystallographic, spectroscopic, and biochemical data indicate that this variant maintains the properties of DrBphP in the resting state. Spectroscopic data also reveal that the armless systems maintain the ability to respond t…
Plasmid Viability Depends on the Ecological Setting of Hosts within a Multiplasmid Community
2022
Plasmids are extrachromosomal genetic elements, some of which disperse horizontally between different strains and species of bacteria. They are a major factor in the dissemination of virulence factors and antibiotic resistance. Understanding the ecology of plasmids has a notable anthropocentric value, and therefore, the interactions between bacterial hosts and individual plasmids have been studied in detail. However, bacterial systems often carry multiple genetically distinct plasmids, but dynamics within these multiplasmid communities have remained unstudied. Here, we set to investigate the survival of 11 mobilizable or conjugative plasmids under five different conditions where the hosts h…
Competition between chain scission and branching formation in the processing of high-density polyethylene: effect of processing parameters and of sta…
2009
Two samples of high-density polyethylene with different molecular weight were processed in a batch mixer and the rheological and structural properties were investigated. In particular, the effect of different processing parameters and the eventual presence of different stabilizers were evaluated. Actually, two reactions may occur during processing: branching/crosslinking or chain scission. The results indicate that when the processing conditions promote a scarce mobility of the macromolecular chains (lower temperatures, lower mixing speed, and higher molecular weight), branching is more favored than chain scission. On increasing the mobility of the chain (higher temperature, higher mixing s…
Struttura galleggiante ad elevata stabilità (Floating structure with high stability)
2015
DESCRIZIONE GENERALE La struttura galleggiante innovativa è composta da diversi elementi modulari collegati fra loro. La composizione modulare della struttura consente di conferirle la lunghezza dettata dalle particolari esigenze da soddisfare. Tipiche applicazioni della struttura galleggiate innovativa sono i pontili, le passerelle pedonali o ciclabili su specchi d'acqua, e in generale le opere finalizzate a consentire lo spostamento di persone, merci e/o veicoli fra punti di uno specchio d'acqua (marino o lacustre) utilizzando strutture galleggianti. Ogni modulo, lungo 10-15 m, è tenuto a galla dalla spinta di Archimede sulle sue parti immerse (le carene), spinta che nella struttura innov…
In vitro evaluation of the influence of bone cortical thickness on the primary stability of conventional- and short-sized implants
2022
Made available in DSpace on 2022-04-28T19:50:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Background: The aim of this in vitro study was to evaluate the influence of the cortical thickness on the primary stability of short and conventional-sized implants with two types of prosthetic connection. Material and Methods: Seventy-two implants were used. These implants were placed in polyurethane blocks that simulated low-density bone tissue (type IV bone), with two bone cortical heights (type I bone): 1mm and 3mm. The implants were divided into 6 groups with 12 implants each according to the type of prosthetic connections (external-hexagon -EH and morse taper- MT) and implant s…
Controversies in ameloblastoma management: Evaluation of decision making, based on a retrospective analysis
2020
Background The ameloblastoma management is still challenging to the high recurrence rates and significant morbidity associated with radical treatment. The purpose of this 10-year retrospective study was to analyze the influence of ameloblastoma type and treatment strategy on the long-term outcomes and recurrence rates. Material and Methods The retrospective analyses of 64 histologically-confirmed ameloblastoma cases was performed. The possible risk factors for recurrence and the development of complications were estimated statistically. Results The treatment strategy applied for this group of patients was the following: thirty-four patients (53.1%) were treated conservatively with enucleati…
Enhancing Metastability by Dissipation and Driving in an Asymmetric Bistable Quantum System.
2018
The stabilizing effect of quantum fluctuations on the escape process and the relaxation dynamics from a quantum metastable state are investigated. Specifically, the quantum dynamics of a multilevel bistable system coupled to a bosonic Ohmic thermal bath in strong dissipation regime is analyzed. The study is performed by a non-perturbative method based on the real-time path integral approach of the Feynman-Vernon influence functional. We consider a strongly asymmetric double well potential with and without a monochromatic external driving, and with an out-of-equilibrium initial condition. In the absence of driving we observe a nonmonotonic behavior of the escape time from the metastable regi…