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Wyszukujesz frazę "radial" wg kryterium: Temat


Tytuł:
Acute Radial Head Resection for Fracture: are We Likely to Miss an Essex-Lopresti Injury?
Autorzy:
Zhang, Dafang
Benavent, Kyra A.
Dyer, George S.M.
Earp, Brandon E.
Blazar, Philip
Powiązania:
https://bibliotekanauki.pl/articles/28409349.pdf
Data publikacji:
2021-08-21
Wydawca:
Fundacja Edukacji Medycznej, Promocji Zdrowia, Sztuki i Kultury Ars Medica
Tematy:
Essex-Lopresti injury
forearm instability
radial head excision
radial head fracture
radial head resection
Opis:
Background. Given the current available evidence, surgical treatment of radial head fracture with acute resection is controversial. The aim of this study was to determine whether acute resection of the radial head for a radial head fracture leads to longitudinal forearm instability due to a missed Essex-Lopresti injury. Material and methods. A retrospective review was conducted of radial head resections performed for acute radial head fractures at two Level I trauma centers from 2000 to 2018. A total of 11 patients met inclusion criteria. Our primary outcome was a missed Essex-Lopresti injury at time of final clinical follow-up. Long-term telephone follow-up was attempted for QuickDASH, pain scores, and satisfaction scores. Results. Of the 11 radial head fractures in this study, intraoperative radial pull tests were performed and normal in 6 patients. No patient was found to have a missed Essex-Lopresti injury at a mean of 36.2 months’ clinical follow-up after radial head resection. At a mean telephone follow-up of 12.6 years in available patients, mean QuickDASH was 3.4, mean satisfaction was 9.75 out of 10, and no further complication or reoperation was reported. Conclusion. Our findings challenge the dogma that the radial head cannot be safely excised in the setting of acute fracture, even with elbow instability and/or wrist pain, particularly when intraoperative longitudinal stability is assessed by a stress maneuver.
Źródło:
Ortopedia Traumatologia Rehabilitacja; 2021, 23(4); 263-270
1509-3492
2084-4336
Pojawia się w:
Ortopedia Traumatologia Rehabilitacja
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD code - a useful tool for the turbomachinery designer
Autorzy:
Chodkiewicz, R.
Sobczak, K.
Papierski, A.
Borzecki, T.
Powiązania:
https://bibliotekanauki.pl/articles/1931600.pdf
Data publikacji:
2002
Wydawca:
Politechnika Gdańska
Tematy:
CFD
radial compressor
radial pump
axial flow turbine
Opis:
The presentation of CFX-TASCflow code possibilities for the turbomachinery design is the main aim of this study. In the first part of the work the compressor design process is presented. Next, CFX-TASCflow possibilities in predicting unstable operating conditions (surge) are shown. The one-stage, radial blower installed in the Institute of Turbomachinery TU of Lodz has been chosen owing to the available numerous experimental data. The pump calculations discussed in the third part concern a comparison of different turbulence models with the experimental results. In the last part devoted to the turbine design, the code usefulness is proved on the examples of the last stage design process.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2002, 6, 4; 553-575
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radial fan controlled with impeller movable blades – CFD investigations
Autorzy:
Jóźwik, K.
Papierski, A.
Sobczak, K.
Obidowski, D.
Kryłłowicz, W.
Marciniak, E.
Wróbel, G.
Marciniak, A.
Wróblewski, P.
Kobierska, A.
Frącczak, Ł.
Podsędkowski, L.
Powiązania:
https://bibliotekanauki.pl/articles/175168.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
radial fan control systems
CFD methods
radial fan performance
partial load
Opis:
Modern classical power generation systems, based on power plants in Poland, where coal (hard bituminous coal or lignite) is the primary energy source, operate under variable loading conditions. Thus, all machines working in the technological system of the power generation unit are required to be adapted to variable loading, and, consequently, to operate beyond the design point of their performance characteristics. High efficiency of the process requires the efficiency of individual devices to be high, beyond the design point, as well. For both air and exhaust gases fans, an effective control system is needed to attain a high level of efficiency. As a result of cooperation between two institutes from the Faculty of Mechanical Engineering, Lodz University of Technology, and the Vibroson company, a new design of the radial fan with impeller movable blades, which allows for controlling the device operation within a wide range, has been developed. This new design and determination the performance characteristics for two geometrical variants of blades with computational fluid dynamics methods are presented. The obtained results have been compared to the results of the measurements of fan performance curves conducted on the test stand.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2016, 131; 17-40
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modernization of a high pressure synthesis gas turbocompressor
Autorzy:
Kryłłowicz, W.
Kozanecki, Z.
Świder, P.
Powiązania:
https://bibliotekanauki.pl/articles/175307.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
syngas
radial compressor
modernization
Opis:
The paper describes several modernization aspects of a three-staged synthesis gas radial turbo compressor. The principal aim was to adapt the machine to new working conditions, resulting from the current state-of-art production technology. The required discharge pressure was changed from 21.1 MPa to 14 MPa. The paper covers the discussion on the scope of modernization, its variants and the final variant choice. It provides review of the thermodynamic calculation methodology, dedicated test stand results and also some of the on-site acceptance tests. The revamped compressor is in continuous service since October 2015.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2016, 131; 121-130
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of reservoir process using the method of radial drilling : [abstract]
Autorzy:
Zhapbasbayev, U. K.
Assilbekov, B. K.
Kabdolov, S. Z.
Khairov, G. B.
Powiązania:
https://bibliotekanauki.pl/articles/300091.pdf
Data publikacji:
2007
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
wiercenie promieniowe
radial drilling
Opis:
At present, a number of methods of improvement of reservoir recovery are well--known: 1) thermal method of effect on productive horizon; 2) formation hydro-breakdown and application of combustible gas energy for organizing of blast in a borehole; 3) acid treatment of wellbottom zone etc. The most common is the first method, which maintains not only producing energy, but due to improvement of rheological characteristics increases oil fluidity. However, this method is applied with large consumption of facilities at pumping and heating of heat carriers. Hydro-breakdown with application of combustible gas energy requires delicate management and may lead to uncontrolled process that is fraught with dangerous situations. The third method generally is suitable for bottomhole formation zone. The method of radial drilling, when reservoirs with high permeability are made for oil withdrawal from strata with low conductive characteristics and extensive dimensions (of high thickness) - is one of effective methods improvement of reservoir recovery. This task is of large interest due to involving in treatment strata with complicated geological structure and for rehabilitation of deposits with abnormal rheological characteristics of oil. The problem is to determine interaction of low-permeable bank of high thickness with high-permeable reservoir, produced by radial drilling method, and find required oil withdrawal for rational exploitation of deposit. The Report presents results of calculation-theoretical study of reservoir recovery using the method of radial drilling. 1. Mathematical model of oil filtration in the bed with high-permeable reservoir, formed in the result of radial drilling, has been developed. High-permeable reservoir represents itself porous medium with filtration characteristics, much exceeding coefficients of permeability of ambient block of high power. In high-permeable reservoir pressure decreases due to fluid withdrawal that leads to fluid influx from ambient low-permeable block. Using representation of mechanics of interpenetrating continuums the process may be described by single equation with different filtration characteristics. Generalized mathematical model of filtration allows automatically meeting conditions of continuity of pressure and mass flows when passing the interface of porous mediums. 2. Obtained calculation data of pressure field and velocity vector illustrate the picture of filtration flow, regularities of interaction between porous block and high-permeable reservoir, and value of fluid influx through the interface depend upon order parameters. 3. The developed mathematical model allows assessing ratios of coefficients of permeability, piezoconductivity of the block and high-permeable reservoir, required for optimal consumption of withdrawing fluid for efficient development of the field with low permeability and higher power.
Źródło:
Wiertnictwo, Nafta, Gaz; 2007, 24, 1; 59-60
1507-0042
Pojawia się w:
Wiertnictwo, Nafta, Gaz
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Further results on radial graphs
Autorzy:
Kathiresan, Kumarappan
Marimuthu, G.
Powiązania:
https://bibliotekanauki.pl/articles/744513.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
radius
diameter
radial graph
Opis:
In a graph G, the distance d(u,v) between a pair of vertices u and v is the length of a shortest path joining them. The eccentricity e(u) of a vertex u is the distance to a vertex farthest from u. The minimum eccentricity is called the radius of the graph and the maximum eccentricity is called the diameter of the graph. The radial graph R(G) based on G has the vertex set as in G, two vertices u and v are adjacent in R(G) if the distance between them in G is equal to the radius of G. If G is disconnected, then two vertices are adjacent in R(G) if they belong to different components. The main objective of this paper is to characterize graphs G with specified radius for its radial graph.
Źródło:
Discussiones Mathematicae Graph Theory; 2010, 30, 1; 75-83
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of super-radial graphs
Autorzy:
Kathiresan, K.M.
Marimuthu, G.
Parameswaran, C.
Powiązania:
https://bibliotekanauki.pl/articles/30148721.pdf
Data publikacji:
2014-11-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
radius
diameter
super-radial graph
Opis:
In a graph G, the distance d(u, v) between a pair of vertices u and v is the length of a shortest path joining them. The eccentricity e(u) of a vertex u is the distance to a vertex farthest from u. The minimum eccentricity is called the radius, r(G), of the graph and the maximum eccentricity is called the diameter, d(G), of the graph. The super-radial graph R*(G) based on G has the vertex set as in G and two vertices u and v are adjacent in R*(G) if the distance between them in G is greater than or equal to d(G) − r(G) + 1 in G. If G is disconnected, then two vertices are adjacent in R*(G) if they belong to different components. A graph G is said to be a super-radial graph if it is a super-radial graph R*(H) of some graph H. The main objective of this paper is to solve the graph equation R*(H) = G for a given graph G.
Źródło:
Discussiones Mathematicae Graph Theory; 2014, 34, 4; 829-848
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New trends in design of instruments for measurements of roundness and cylindricity
Autorzy:
Stępień, K.
Powiązania:
https://bibliotekanauki.pl/articles/132109.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
roundness
cylindricity
measurement
radial method
Opis:
The paper deals with modern systems for roundness and cylindricity measurements. It gives the classification of methods for roundness and cylindricity measurement and it describes more precisely the radial method. Fundamental part of the paper is presentation of measuring abilities of Talyrond 365. In the summary a brief comparison between of and new systems for cylindricity measurements are given.
Źródło:
Advanced Technologies in Mechanics; 2014, 1, no. 1 (1); 19-27
2392-0327
Pojawia się w:
Advanced Technologies in Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of methods for the determination of Tesla turbine performance
Autorzy:
Rusin, Krzysztof
Wróblewski, Włodzimierz
Strozik, Michał
Powiązania:
https://bibliotekanauki.pl/articles/280194.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
Tesla turbine
roughness
radial turbine
Opis:
A numerical and experimental investigation of the Tesla turbine is presented in the paper. The experiment is conducted for various inlet pressure and load. The roughness of the rotor disc is determined as it is a key factor to obtain high turbine efficiency and power. The numerical investigations are performed for the same conditions as in the experiment. The computational results are compared with the analytical model. Comparison of performance characteristics show a relatively good agreement between the experiment and CFD. The analytical model overestimates distributions of pressure and circumferential velocities, although the predicted power is on the similar level as in the experiment and CFD.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 3; 563-575
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical surge modeling based on the pressure oscillations in the stable operation range of the compressor
Autorzy:
Jaeschke, A.
Liśkiewicz, G.
Powiązania:
https://bibliotekanauki.pl/articles/175279.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
radial compressors
surge
Greitzer model
Opis:
Prevention of surge phenomenon is a very active field of research in last decades. The Greitzer model is the most widely applied mathematical model describing the surge phenomenon. Two parameters that characterize the given compressing system: the Helmholtz oscillator frequency and the so-called B parameter have to be given as the input to Greitzer model. Although those parameters are easy to determine for simplified compressor models, they are extremely hard to predict in case of real industrial compressors. Moreover, in most cases it is impossible to analyse compressor unstable work, which makes this prediction even more speculative. Therefore the method that determines the parameters basing on the compressor stable operation is indispensable. In paper the regularly perturbed Greitzer model based method of predicting the behaviour of a compressor in the unstable operation basing on signals from its stable operation is proposed and discussed.
Źródło:
Transactions of the Institute of Fluid-Flow Machinery; 2016, 133; 91-108
0079-3205
Pojawia się w:
Transactions of the Institute of Fluid-Flow Machinery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of the long term use of a computer on median, ulnar and radial sensory nerves in the wrist region
Autorzy:
Bamac, Belgin
Colak, Serap
Dundar, Gulmine
Selekler, Hamit M.
Taşkiran, Yavuz
Colak, Tuncay
Balci, Emin
Powiązania:
https://bibliotekanauki.pl/articles/2179017.pdf
Data publikacji:
2014-12-01
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
computer users
ulnar
median
radial
nerve
Opis:
Objectives: Repetitive microtrauma or overuse injuries may often affect upper extremities of the long term computer users. The aim of this study was to compare sensory nerve conduction velocities (SNCV) for median, radial and ulnar nerves in the wrist of computer users with the same parameters in controls who do not use computers regularly. Material and Methods: Twenty one male computer users (age: mean (M) = 28.3 years ± standard deviation (SD) = 7.5 years) and 21 male control subjects (age: M±SD = 24.1±4.6 years) were recruited for the study. Limb length and the perimeters of the dominant arm and forearm were measured for each subject. The neurophysiological study consisted of measuring sensory nerve conduction of the median, ulnar and radial nerves. Results: The sensory conduction velocities of both median and ulnar nerves were significantly delayed in the dominant arm of the computer users compared to the controls. In addition, sensory conduction velocity of the median nerve was significantly delayed in the dominant extremity of the computer users compared to their non-dominant extremity. Conclusions: This study shows that computer users have a tendency toward developing median and ulnar sensory nerve damage in the wrist region. Mechanism of delayed SNCV in the median and ulnar nerves may be due to sustained extension and ulnar deviation of the wrist during computer mouse use and typing. Reduced SNCV changes were more apparent on the dominant side of the median nerve. This may indicate the increased neural deficits related to an increased use of the dominant side. Further investigation is needed to determine how to reduce potential risk factors at this stage in order to prevent development of median or ulnar neuropathy in the long term computer users.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2014, 27, 6; 1026-1035
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modal Analysis of a Steel Radial Gate Exposed to Different Water Levels
Autorzy:
Brusewicz, K.
Sterpejkowicz-Wersocki, W.
Jankowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/241116.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
modal analysis
radial gate
dynamic loads
Opis:
With the increase in water retention needs and planned river regulation, it might be important to investigate the dynamic resistance of vulnerable elements of hydroelectric power plants, including steelwater locks. The most frequent dynamic loads affecting hydroengineering structures in Poland include vibrations caused by heavy road and railway traffic, piling works and mining tremors. More destructive dynamic loads, including earthquakes, may also occur in our country, although their incidence is relatively low. However, given the unpredictable nature of such events, as well as serious consequences they might cause, the study of the seismic resistance of the steel water gate, as one of the most vulnerable elements of a hydroelectric power plant, seems to be important. In this study, a steel radial gate has been analyzed. As far as water gates are concerned, it is among the most popular solutions because of its relatively small weight, compared to plain gates. A modal analysis of the steel radial gate was conducted with the use of the FEM in the ABAQUS software. All structural members were modelled using shell elements with detailed geometry representing a real structure.Water was modelled as an added mass affecting the structure. Different water levels were used to determine the most vulnerable state of the working steel water gate. The results of the modal analysis allowed us to compare the frequencies and their eigenmodes in response to different loads, which is one of the first steps in researching the dynamic properties of steel water gates and their behaviour during extreme dynamic loads, including earthquakes.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2017, 64, 1; 37-47
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The problem with flow in radial channels synchronous machine
Autorzy:
Makki, Z.
Janda, M.
Deeb, R.
Powiązania:
https://bibliotekanauki.pl/articles/377188.pdf
Data publikacji:
2012
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
radial channels
synchronous machine
flow rate
Opis:
This paper describes the use of computational methods for solving the flow of the air-cooling in the large synchronous machines where it is used to cool the stator winding and stator radial channels which are located between the stator packet sheets. The overall process flow is mostly influenced by the size of air gap between stator and rotor, the shape of the radial channels, and by flow rates in machines. This paper mostly discusses about the influence flow rate of the cooling medium which has effects on the pressure distribution and flow rate in the radial channels. Cooling medium considered in this article an air and for and for calculation was chosen ANSYS CFX.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2012, 72; 75-82
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radial growth of pedunculate oak and European ash on active river terraces. Hydrologic and climatic controls
Autorzy:
Okoński, B.
Powiązania:
https://bibliotekanauki.pl/articles/100989.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Stowarzyszenie Infrastruktura i Ekologia Terenów Wiejskich PAN
Tematy:
oak
ash
floodplain forest
radial growth
Opis:
The aim of this study was (1) to assess relationships binding hydroclimatic factors and radial growth of pedunculate oak and European ash growing on active terraces of river valleys; (2) to compare the growth reaction of these species from this location. Research site was located in a floodplain valley, within mid-course of the lowland section of the Warta River in the Lasy Czeszewskie Forest, Poland. The Warta River (length 808 km, basin area: 54,529 km2 ) is a mid-size European river, a tributary of the Odra River draining the North European Plain to the Baltic Sea. The sampled forest stand was an old growth composed of pedunculate oak and European ash mixed with other mature tree species. The main conclusions are: (1) ash in comparison to oak growing on the same site located on floodplains appeared to be both more sensitive to hydroclimatical features and less ecologically flexible as far as monthly pattern of water requirements is concerned, therefore adaptation to changing climatic conditions and drought may be a greater ecological challenge for ash than for oak in river valleys; (2) streamflow could be considered as the parameter that substituted precipitation well, or even was more important than precipitation, as far as availability of water for development of tree rings of ash and oak growing on active terraces of river valleys is concerned; however, the role of streamflow in radial growth developing decreased substantially during 20th century; (3) Standardized Precipitation Evapotranspiration Index (SPEI) as a measure of drought is a prospective parameter in dendroecological analysis, since it conveys real availability of water for trees.
Źródło:
Infrastruktura i Ekologia Terenów Wiejskich; 2017, III/1; 1075-1091
1732-5587
Pojawia się w:
Infrastruktura i Ekologia Terenów Wiejskich
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Układ wylotowy typu kolana sprężarki promieniowej i osiowo-promieniowej
Autorzy:
Antas, Stanisław
Powiązania:
https://bibliotekanauki.pl/articles/2032833.pdf
Data publikacji:
2020
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
sprężarka promieniowa
sprężarka osiowo-promieniowa
kanał wylotowy
kolano
radial compressor
axial-radial compressor
exhaust duct
knee
Opis:
Kolano jest układem wylotowym kanału przepływowego sprężarki promieniowej i osiowo-odśrodkowej, w którym następuje zmiana kierunku przepływu z promieniowego na kierunek wyznaczony przez oś dyfuzora komory spalania. W pracy przedstawiono metodę wyznaczania parametrów strumienia w przekroju wyjściowym układu wylotowego sprężarki promieniowej i osiowo-odśrodkowej. Analiza obejmuje układ wylotowy typu kolana. Zaprezentowano także odpowiednią metodę określania parametrów geometrycznych dla kanału wylotowego tego typu. Wymienione metody mogą być stosowane w trakcie realizacji projektu koncepcyjnego sprężarki, a oparto je na równaniu zachowania energii, równaniu ciągłości przepływu, pierwszej i drugiej zasadzie termodynamiki oraz funkcjach gazodynamicznych i definicjach używanych w teorii maszyn wirnikowych. Końcowa część pracy zawiera zasady doboru obliczeniowej wartości sprężu sprężarki z promieniowym dyfuzorem łopatkowym oraz wnioski.
Źródło:
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika; 2020, z. 92 [300], 1; 29-43
0209-2689
2300-5211
Pojawia się w:
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
Dostawca treści:
Biblioteka Nauki
Artykuł

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