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PL
W pracy przeprowadzono badania stabilności składnika warstwy receptorowej biosensora po dodaniu nanocząstek złota. Wykazano przyspieszone zmiany konformacyjne pod wpływem Au. Obliczono względne procentowe zmiany w czasie między czystym białkiem a białkiem domieszkowanym Au. Wykazano, że z czasem zmiany te są większe i przekraczają 20 % w ostatnich dniach eksperymentu.
EN
In this study, the stability of the receptor layer component of a biosensor after addition of gold nanoparticles was investigated. Accelerated conformational changes under the influence of Au were demonstrated. The relative percentage changes over time between the pure protein and the Au doped protein were calculated. It was shown that these changes are greater with time and exceed 20 % in the last days of the experiment.
EN
Alkyl amines are widely used as cationic collectors in flotation. In this work, the flotation foaming behaviors of alkyl amines, including dodecylamine (DDA), di-n-hexylamine (DHA), octadecylamine (ODA), oleylamine (OLA), in the presence or absence of quartz were investigated by a new approach, “foam analyzer”. The effects of pH, reagent dosage, concentration of quartz powder, and particle size on foaming property and stability of bubble were explored, and the physical model of foam structure evolution was established. The adsorption mechanism of amines on quartz surface was studied from molecular structure, surface tension, zeta potential, charging mode, and adsorption form. The results show the foam stability of four amine collectors as follows: OLA > ODA > DHA > DDA. In the range of pH=6-10, the foam properties of the four amines are better. Under the same conditions, the longer carbon chain of aliphatic amine, the more unsaturated bonds, the fewer hydrogen atoms of the amine group, and the corresponding foam properties are better. When the concentration of quartz powder is 8-10%, the foaming and stability of the foam of four kinds amines are the best, The finer quartz powder particle size, the more stable the amine foam and the stronger the foamability.
3
Content available The Stability Interval of the Set of Linear System
EN
The article considers the problem of stability of interval-defined linear systems based on the Hurwitz and LienardShipar interval criteria. Krylov, Leverier, and Leverier-Danilevsky algorithms are implemented for automated construction and analysis of the interval characteristic polynomial. The interval mathematics library was used while developing the software. The stability of the dynamic system described by linear ordinary differential equations is determined and based on the properties of the eigenvalues of the interval characteristic polynomial. On the basis of numerical calculations, the authors compare several methods of constructing the characteristic polynomial. The developed software that implements the introduced interval arithmetic operations can be used in the study of dynamic properties of automatic control systems, energy, economic and other non-linear systems.
EN
The paper is devoted to a particular case of the nonlinear and nonautonomous control law design problem based on the application of the optimization approach. Close attention is paid to the controlled plants, which are presented by affine-control mathematical models characterized by integral quadratic functionals. The proposed approach to controller design is based on the optimal damping concept firstly developed by V.I. Zubov in the early 1960s. A modern interpretation of this concept allows us to construct effective numerical procedures of control law synthesis initially oriented to practical implementation. The main contribution is the proposition of a new methodology for selecting the functional to be damped. The central idea is to perform parameterization of a set of admissible items for this functional. As a particular case, a new method of this parameterization has been developed, which can be used for constructing an approximate solution to the classical optimization problem. Applicability and effectiveness of the proposed approach are confirmed by a practical numerical example.
EN
Diagnostics of stability of the cores constructions, elements of the carrier system of the ship and port facilities, reduces to the definition of critical forces, excess which causes a transition of the system from one equilibrium state to another. Such a transition often leads to the destruction of the constructions or other forms of accidents, and therefore it is extremely undesirable and for practice it is important to knowledge of a specific spectrum of critical forces and their corresponding forms of loss of stability.
EN
Recently in many cities of the world began to introduce so-called «metrobus» or BRT (Bus Rapid Transit) systems, which became a cheaper alternative to the metro and other rail transport, in particular trams. The aim of the work is to determine the stability indicators of the metrobus in the transitional traffic modes, in particular when performing such manoeuvres as «steering wheel jerk» and «shuffle». For this purpose, the equations of metrobus plane-parallel motion are supplemented by equations of the links of the road train in the vertical plane by halopilation (tangage, trim) and roll. The critical straight-line speed of the three-link metrobus has been determined, which was 32,06 m/s, and this speed is independent of the corners of the steering wheels of the bus and the trailer links. It has been shown that as the steering wheel angle of the bus increases, the difference in the folding angles of the bus increases, with the second folding angle significantly exceeding the first, especially considering the roll of the metrobus body. It has been established that the greatest rolls and loads of the metrobus axles are those of the last trailer, which is the limiting factor for the critical speed. The lateral accelerations of individual metrobus links and their yaw velocity when performing the manoeuvre «steering wheel jerk» and «shuffle, Sl = 24 m», show that both the bus and the second trailer link are a limiting factor when performing various manoeuvres, but the acceleration value does not exceed the permissible 0.4 g, so its stability under these conditions is ensured.
7
EN
This paper presents a dynamic model of a palletised load unit during a static tilt test. The stability (also called rigidity) of a load unit was evaluated. The palletised load unit was built of packages forming layers and protected against disintegration by stretch film. The aim of this study was to compare the results of a static tilt test with a commonly used and recommended dynamic acceleration test.
8
EN
Purpose: The purpose of the paper is to present the concept of providing organizational structure with necessary stability and variability. Design/methodology/approach: The concept draws from the results of a case study on the Society of Jesus (Jesuits), an organization that dates back to the first half of the sixteenth century, whose leaders assure great adaptive capacity, as well as stability and identity at the same time. Findings: The article sheds light on combining stability and variability during the structuring of organizations and presents a new approach, which builds on the principles of continuity and simplicity. Originality/value: Unlike the well-known organization life cycle models, which consider the organizational structure as a relatively stable element, that is subject to significant transformations when progressing through the life cycle phases, the presented concept favors evolutionary development of structures based on dynamic focusing of continuity and simplicity. The simultaneous observance of both principles has not yet been presented in the literature.
PL
Ideą pracy badawczej była analiza wybranych właściwości mechanicznych lokomotywy EP09. Za główny cel artykułu obrano analizę stabilności lokomotywy EP09, poprzez określenie prędkości krytycznej pojazdu. W tym celu w powyższej publikacji opisano w jaki sposób został zamodelowany układ obliczeniowy, jakie parametry i założenia zostały przyjęte do przeprowadzenia symulacji oraz zaprezentowano końcowe wyniki na podstawie których określono prędkość krytyczną pojazdu. Aby wyniki symulacji były w jak największym stopniu tożsame z wynikami rzeczywistymi, do stworzenia modelów symulacyjnych lokomotywy oraz wózka wykorzystano materiały i wyniki badań uzyskane z Instytutu Pojazdów Szynowych Tabor w Poznaniu. Większość obliczeń została wykonana w programie SIMPAK. W wyniku przeprowadzonej symulacji i analizy uzyskanych wyników określona została prędkość krytyczna lokomotywy EP09, przy której pojazd traci stabilność ruchu.
EN
The idea of the research was analysis selected mechanical preferences of the locomotive EP09. As the main objective of article was chosen analysis of the stability of the locomotive EP09 by define the critical speed of the vehicle. With this and in view in this publication was described how the calculative model was built, what parameters and assumptions were taken to simulate and presented the final results on the basis of which identified the critical speed of the vehicle. In order to simulation results were as much as possible the same as the real results, to create simulation models locomotive and trolley, there have been used information and the research results obtained from the Institute of Rail Vehicles Tabor in Poznan. Most of the calculations has been made in the computer software SIMPLE. As a result of the simulation and analysis of the results was defined the critical speed of locomotive EP09, at which the vehicle loses stability movement.
EN
This article presents a modified incremental model describing pre-failure deformations of granular soils under classical triaxial conditions. The original shape of equations has been proposed by Sawicki and Świdziński [40, 41]. A new form of equations that are consistent with the proposed definitions of deviatoric loading and unloading is suggested. Triaxial tests necessary for calibrating the proposed model have been performed. The modified model is used to simulate the deformations and stability of sand for every pre-failure loading path and makes it possible to describe the behaviour of granular soil under both drained and undrained conditions. A comparison of experimental and numerical results is presented. All investigations were performed in a classical tri-axial apparatus.
PL
Przedstawiono wyniki badań stabilności fazowej dwóch gatunków ropy naftowej, które posłużyły do opracowania procedury znajdowania kompatybilnej mieszaniny. Metoda polegała na wykreśleniu zależności między parametrem Heithausa a zawartością poszczególnych grup węglowodorów, a następnie wyznaczeniu optymalnego składu. Przewidywane wyniki weryfikowano za pomocą zmodyfikowanego testu filtracji na gorąco.
EN
The colloidal stability index (Heithaus parameter) was detd. for 2 types of crude oil differing in phys.-chem. properties and for their mixts. (25, 50 and 75% by mass) by turbidimetry. The relationship between the Heithaus parameter and content of particular hydrocarbon groups was plotted and the optimal mixt. compn. was detd. The result of prediction by using the developed model were confirmed by a modified hot filtration test.
PL
Napromienianie śródoperacyjne w onkologii polega na wykonaniu jednorazowej radioterapii bezpośrednio w loży pooperacyjnej w ciele chorego, po wyciętej podczas operacji chirurgicznej tkance nowotworowej. Celem zabiegu jest zniszczenie ewentualnie nieusuniętych komórek nowotworowych, korzystając z bezpośredniego do nich dostępu. Proces dokowania akceleratora śródoperacyjnego, czyli zgrywania osi wiązki terapeutycznej z osią loży pooperacyjnej, ułatwiłaby jego automatyzacja. Jednak automatyczne przesuwanie całego aparatu stwarza znaczne ryzyko. Publikacja analizuje jeden z wariantów automatycznego bezpiecznego dokowania wykonywanego w dwóch etapach. W pierwszym etapie operator wstępnie pozycjonowałby głowicę akceleratora, a przede wszystkim wyjście wiązki elektronów względem aplikatora umieszczonego już w loży, w drugim realizowano by automatyczne, precyzyjne dosunięcie samej głowicy akceleratora do aplikatora. To rozwiązanie wymaga stworzenia możliwości wykonania w poziomie ruchów kolumny akceleratora wraz z ramieniem i głowicą względem podstawy aparatu. Opracowanie przedstawia analizę możliwości wprowadzenia do konstrukcji akceleratora zbudowanego w Narodowym Centrum Badań Jądrowych układu realizującego przedstawione wymaganie.
EN
Intraoperative irradiation in oncology involves performing one-off radiotherapy directly on the operating bed in the patient’s body, in the place after tumor tissue resection during surgery. The aim of the procedure is to destroy any undeleted cancer cells by using direct access to them. The process of docking the intraoperative accelerator, i.e. bringing the therapeutic beam axis into line with the axis of the site after tumor resection, would facilitate its automation. However, automatically moving the accelerator creates significant risks. One of the considered variants of automatic docking is to carry out itin two steps. In the first step, the operator would initially position the accelerator head, and above all the electron beam output relative to the applicator already located at the tumor resection site, in the second automatic step, precise approach of the accelerator head to the applicator would follow. Such a solution requires ensuring horizontal movements of the column with the arm and the accelerating head in relation to the base of the unit. The paper presents an analysis of the possibility of introducing to the accelerator built at the National Centre for Nuclear Research a system implementing the presented requirement.
PL
W artykule przedstawiono bardzo ogólnie przykłady współczesnych możliwości analizy konstrukcji stalowych w odniesieniu do komercyjnego oprogramowania inżynierskiego w aspekcie praktycznym. Prezentowane przykłady pochodzą z rzeczywistych analiz wykonanych na potrzeby prac badawczych, ekspertyz lub projektów zrealizowanych przez autora i jego współpracowników. Są więc one przykładem praktycznego wykorzystania procedur i teorii potocznie uważanych za akademickie.
EN
The paper presents generally examples of recent possibilities for analyzing steel structures in environment of commercial engineering software in a practical aspect. The examples presented come from real analyses carried out for research work, expertise or projects carried out by the author and his team. They are therefore an example of the practical use of procedures and theories colloquially known as academic.
EN
The proposed study is improvised value-engineered modifications for the basic interleaved boost converter (IBC) by including relevant modifications in circuits, which is expected for a better performance in switching with reduction in losses. The newly modified IBC circuit with insulated gate bipolar transistor (IGBT) along with converter has been experimented by simulations and the results are tabulated to modified IBC with metal oxide silicon field effect transistors. Further experimental analysis and validations of the proposed simulation with hardware developed adopting model SKM195GB066D consisting of IGBTs is presented. This study further enhances and summarises the optimum utilisation and the performance of IBC with the proposed IGBT modules that synchronises power diode. Enhancing the simulation outcomes, the hardware is proposed and developed to be tested for a load up to 1.5 kW with the evaluation of key parameters such as efficiency of the converter.
EN
The aim of the work presented in the article is to determine the effect of the type of fat and the variable protein content of algae on selected physicochemical properties of emulsions determining the stability of the disersion systems. Fat emulsions were prepared in the following three variants: based on hemp oil, based on a mixture of hemp oil and mutton tallow (1: 1) and based on the same fat mixture, but subjected to the enzymatic interesterification process (1: 1). The experimental part of the work included the preparation of animal fat by subjecting it to the bleaching process, and then enzymatic interesterification with hemp oil. Then, 9 variants of emulsions containing hemp oil, nonesterified fat mixture and interesterified fat mixture, respectively, were prepared. Each emulsion had a different algal protein content ranging from 0.4 to 1.2% by weight of the emulsion. The emulsions prepared in this way were tested 24 hours after their preparation and after 1 month of storage. The following parameters of the emulsion were assessed: color, texture, viscosity, and microscopic structure, and the intensity of the light backscattered by the sample was measured with the use of the Turbiscan Lab device. It was noticed that with the increase in the protein content of algae in the emulsions, there was an increase in the value of the b * parameter corresponding to the yellow color for all variants of these emulsions. There was also an increase in droplet size in microscopic examination and a decrease in the stability of the emulsions based on the interesterified fats. There was no unequivocal influence of the algae protein on the following parameters: emulsion adhesiveness, viscosity and hardness.In the study, it was not possible to select an emulsion with high stability, nor to indicate a clear influence of protein on the rheological properties of the emulsions produced, regardless of the type of fat used. In order to produce more stable systems, research should be extended to change the amount or type of protein, or to select a different viscosity modifier which, together with the algae protein, is able to create a synergistic system that stabilizes the dispersion systems produced.
PL
Celem pracy przedstawionej w artykule jest określenie wpływu rodzaju tłuszczu oraz zmiennej zawartości białka z alg na wybrane właściwości fizykochemiczne emulsji decydujące o stabilności układu. Emulsje tłuszczowe wytworzono w trzech następujących wariantach: na bazie oleju konopnego, na bazie mieszaniny oleju konopnego i łoju baraniego (1:1) oraz na bazie tej samej mieszaniny tłuszczowej, ale poddanej procesowi enzymatycznego przeestryfikowania (1:1). Zakres eksperymentalnej części pracy obejmował przygotowanie tłuszczu zwierzęcego (łoju baraniego) przez poddanie go procesowi bielenia, a następnie przeestryfikowanie enzymatyczne z olejem konopnym. Następnie przygotowano 9 wariantów emulsji zawierających odpowiednio olej konopny, mieszaninę tłuszczową nieprzeestryfikowaną oraz mieszaninę tłuszczową przeestryfikowaną. Każda z emulsji zawierała inną zawartość białka z alg w ilości od 0.4 do 1,2% w stosunku do masy emulsji. Tak przygotowane emulsje poddano badaniom po 24 godzinach od ich sporządzenia oraz po 1 miesiącu przechowywania. Przeprowadzono ocenę następujących parametrów emulsji: barwy, tekstury, lepkości, struktury mikroskopowej oraz dokonano pomiaru intensywności światła wstecznie rozproszonego przez próbkę w czasie, z wykorzystaniem urządzenia Turbiscan Lab. Zauważono, że wraz ze wzrostem zawartości białka z alg w emulsjach, nastąpił wzrost wartości parametru b* odpowiadającego za żółty kolor dla wszystkich wariantów tych emulsji. Nastąpił również wzrost wielkości kropel w badaniu mikroskopowym i zmniejszenie stabilności emulsji na bazie tłuszczów przeestryfikowanych. Nie zauważono jednoznacznego wpływu białka z alg na następujące parametry: adhezyjność, lepkość oraz twardość emulsji.W pracy nie udało się wytypować emulsji o wysokiej stabilności, ani wskazać wyraźnego wpływu białka na właściwości reologiczne wytworzonych emulsji bez względu na rodzaj zastosowanego tłuszczu. W celu wytworzenia bardziej stabilnych układów należy rozszerzyć badania w kierunku zmiany ilości lub rodzaju białka, czy wytypowania innego modyfikatora lepkości, który z białkiem z alg jest w stanie stworzyć układ synergistyczny oddziaływający stabilizująco na wytworzone układy dyspersyjne.
EN
Usually, the concept of sufficient stability of a floating structure is connected with the capacity to keep a small heel angle despite the moment of heeling. The variable responsible for these characteristics is the initial metacentric height, which is the relation between the hydrostatic features of the pontoon and the mass properties of the entire object. This article answers the questions of how heavy the floating system should be, what the minimum acceptable draft is, and whether it is beneficial to use internal fixed ballast. To cover various technologies, a theoretical model of a cuboid float with average density representing different construction materials was analysed. The results indicate that the common practice of using heavy and deep floating systems is not always reasonable. In the case of floating buildings, which, unlike ships, can be exploited only under small heel angles, the shape and width of the submerged part of the object may influence the stability more than the weight or draft.
EN
Four years of observations of radon, meteorology and atmospheric pollution was used to demonstrate the efficacy of combined diurnal and synoptic timescale radon-based stability classification schemes in relating atmospheric mixing state to urban air quality in Zgierz, Central Poland. Nocturnal radon measurements were used to identify and remove periods of non-stationary synoptic behaviour (13–18% of each season) and classify the remaining data into five mixing states, including persistent temperature inversion (PTI) conditions, and non-PTI conditions with nocturnal conditions ranging from well mixed to stable. Mixing state classifications were performed completely independently of site meteorological measurements. World Health Organization guideline values for daily PM2.5/PM10 were exceeded only under strong PTI conditions (3–15% of non-summer months) or often under non-PTI stable nocturnal conditions (14–20% of all months), when minimum nocturnal mean wind speeds were also recorded. In non-summer months, diurnal amplitudes of NO (CO) increased by the factors of 2–12 (3–7) from well-mixed nocturnal conditions to PTI conditions, with peak concentrations occurring in the morning/evening commuting periods. Analysis of observations within radon-derived atmospheric mixing ‘class types’ was carried out to substantially clarify relationships between meteorological and air quality parameters (e.g. wind speed vs. PM2.5 concentration, and atmospheric mixing depth vs. PM10 concentration).
EN
Support stability is critical to ensure fully-mechanized top coal caving of large dip angle coal seam. To obtain the relations between each factor and hydraulic support stability, the mechanic model of large dip angle coal seam along face dip and strike was built to analyze support stability, including antitoppling, anti-slip, and anti-rotation of supports. The result indicates: Along the face dip, the suport stability was negatively correlated with dip angle; Higher top caving means lower anti-rotation at suport tail; With initial support force and working resistance of supports enhanced, the anti-slip, and antirotation stability of supports can be risen significantly. Along the strike, the critical toppling angle was proportional to dip angle, mining height, support weight, support width and support force; The critica slip angle was positive correlation with support force, friction coefficient of roof and supports. According to the results of both mechanical analysis and engineering projects, support stability in large dip angle can be risen efficiently and supports slipping, toppling and rotation can be avoided by selecting proper technical methods and equipment, like enhancing initial support force appropriately.
EN
The paper focuses on measuring and evaluating the impact of selected technical and technological factors - the height of adjustable guides and stretching force - on the side deflection of the saw band of a joinery band saw. There is a detailed description of the ways the side deflection can be measured. In order to find out the intensity of the stretching force was used portable tension meter SANDVIK 5000, enabling to check the tensile stress in the saw blades of a gang saw or in the saw bands of a band saw. The actual experiment was conducted on a joinery band saw, at the cutting rate vc = 15 m·s-1. The results of the measurements confirmed the theoretical assumption of the impact of the selected technical and technological factors on the stability of the saw band, where the side deflection decreases with increasing stretching force and increases with increasing height of the guides. The stability of the saw band affects the quality of the surface to be treated, thus saving the cost of machining the workpiece and making work productivity more efficient.
EN
In this paper, an analytical model is proposed to predict lateral vibration of a drillstring in a vertical well. The effect of parameters, such as stiffness of spring, average weight on bit (WOB), amplitude of fluctuating WOB and so on, on the dynamic stability of the drillstring is discussed. It is found that the interaction between the drillstring and drilling mud has a great influence on drillstring buckling and dynamics. For constant drilling pressure, the mud flow rate stabilizes the drillstring under certain conditions, but the fluctuating WOB drives the drillstring parametric resonance.
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