Wyniki wyszukiwania - Biblioteka Nauki

1

Hydraulic Research of Sediment Transport in the Vertical Slot Fish Passes

100%

Mumot J. , Tymiński T.

Journal of Ecological Engineering

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2016

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tom Vol. 17, nr 1

143--148

EN

The physical model of vertical slot fishway was conducted. On the fishway a device used for sediment dispense was installed. The sediment was dispensed to each chamber. Measurements of approx. height of the water table, measurements of flow rate, observation of line streams in chambers were carried out during the studies. The flows of sediment and hydraulic parameters inside designed fishway, single compartments and their connection with sedimentation process in individual chambers were also studied. the obtained research results constitute starting point for experimental analyses and research analyses. Based on the observation and measurements it is possible to state that the constructed physical model reflects the activity conditions of the vertical slot fishway. During the studies a place of deposition in sediments of individual fishway chambers were determined.

2

The analysis of factors influencing the dynamics of lowland riverbed erosion downstream of the Jeziorsko reservoir dam (central Poland)

100%

Smaga A. , Wierzbicki J. , Wierzbicki M. , Hämmerling M. , Radaszewski R.

Geological Quarterly

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2017

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tom Vol. 61, No. 4

926--933

EN

Increased riverbed erosion could recently be observed in close vicinity of hydrotechnical constructions in many lowland rivers. The immediate effect of erosion in this case is a very significant reduction of the riverbed level over a considerable distance, downstream of large reservoir dams. This process is influenced simultaneously by both hydraulics of river flow and geotechnical properties of soil eroded. The paper presents an analysis of parametric changes in the level of river bottom and grain size of bed material, and the relative density in the context of changes in hydrological conditions and diversity of engineering-geological conditions. As the result, a multiparametric model of erosional potential of riverbed sediments has been proposed, which can significantly help in proper planning of locations and construction of correction thresholds under given hydraulic conditions of the river.

3

Numerical study of wave transmission over double submerged breakwaters using non-hydrostatic wave model

100%

Liang B. , Wu G. , Liu F. , Fan H. , Li H.

Oceanologia

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2015

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tom 57

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nr 4

4

Synthesis and evaluation analysis of the indicator information in nuclear safeguards applications by computing with words

100%

Liu J. , Ruan D. , Carchon R.

International Journal of Applied Mathematics and Computer Science

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2002

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tom 12

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nr 3

449-462

EN

This paper aims at the handling and treatment of nuclear safeguard relevant information by using a linguistic assessment approach. This is based on a hierarchical analysis of a State's nuclear activities in a multi-layer structure of the evaluation model. After a hierarchical analysis of the State's nuclear activities on the basis of the IAEA Physical Model, the addressed objective is divided into several less complex levels. The overall evaluation can be obtained step by step from those lower levels. Special emphasis is put on the synthesis and evaluation analysis of the Physical Model indicator information. Accordingly, the aggregation process with the consideration of the different kinds of qualitative criteria is in focus. Especially, the symbolic approach is considered by the direct computation on linguistic values instead of the approximation approach using the associated membership function. In this framework, several kinds of ordinal linguistic aggregation operators are presented and analyzed. The application of these linguistic aggregation operators to the combination of the Physical Model indicator information is provided. An example is given to support and clarify the mathematical formalism.

5

Hydraulic jump and energy dissipation with stepped weir

100%

Azmeri A. , Basri H. , Yulianur A. , Ziana Z. , Jemi F. Z. , Rahmah R. A.

Journal of Water and Land Development

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2021

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tom no. 51

56--61

EN

Energy dissipator functions to dissipate the river-flow energy to avoid longitudinal damage to the downstream river morphology. An optimal energy dissipator planning is essential to fulfilling safe specifications regarding flow behavior. This study aims to determine the variation of energy dissipators and evaluate its effect on the hydraulic jump and energy dissipation. For this purpose, a physical model was carried out on the existing weir condition (two steps). It was also carried out on four stepped-weir variations, i.e., three-step, three-step with additional baffle blocks at the end sills, four-step, and six-step. Dimensional analysis was employed to correlate the different parameters that affect the studied phenomenon. The study shows a three-step jump shows a significantly higher Lj/y1 ratio, which is an advantage to hydraulic jumps’ compaction. The comparison of energy dissipation in all weir variations shows that the three-stepped weir has wasted more energy than other types. The energy dissipation increase of the three-step type is 20.41% higher than the existing type’s energy dissipation and much higher than other types. The dimensions of the energy dissipation basin are the ratio of the width and height of the stairs (l/h) of the three-step type (2.50). Therefore, this type is more optimal to reduce the cavitation risk, which damages the river structure and downstream area.

6

Synthesis and Evaluation Analysis of the Indicator Information in Nuclear Safeguards Applications by Computing With Words

88%

Liu J. , Ruan D. , Carchon R.

International Journal of Applied Mathematics and Computer Science

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2002

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tom Vol. 12, no 3

449-462

EN

This paper aims at the handling and treatment of nuclear safeguard relevant information by using a linguistic assessment approach. This is based on a hierarchical analysis of a State's nuclear activities in a multi-layer structure of the evaluation model. After a hierarchical analysis of the State's nuclear activities on the basis of the IAEA Physical Model, the addressed objective is divided into several less complex levels. The overall evaluation can be obtained step by step from those lower levels. Special emphasis is put on the synthesis and evaluation analysis of the Physical Model indicator information. Accordingly, the aggregation process with the consideration of the different kinds of qualitative criteria is in focus. Especially, the symbolic approach is considered by the direct computation on linguistic values instead of the approximation approach using the associated membership function. In this framework, several kinds of ordinal linguistic aggregation operators are presented and analyzed. The application of these linguistic aggregation operators to the combination of the Physical Model indicator information is provided. An example is given to support and clarify the mathematical formalism.

7

The physical model of changes setting in multilayer bearings

88%

Kowalczyk S.

Journal of KONES

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2009

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tom Vol. 16, No. 1

281-288

EN

This work presents the physical model of changes setting in multilayer bearing of combustion engines. It is known, that the slide bearing of high-load combustion engines independently from manufacturing technology, must have a material stability with regard on diffusion process of the alloy components. The present state of materials used on slide multilayer bearings of combustion engines has not changed during the last 30-year. Only small changes and modifications of material multilayer bearings, with the use of the same groups of materials, independently from specific manufacturing technology of bearing and their use were observed. The change of bearings materials. growth of operating requirements of combustion engines, ecological limitation and the price of materials may force changes in present constructional and technological conception of multilayer, in range of materials selection and huilding the bearings. This work presents the physical model of changes setting in multilaver bearing on different building. U was found that the slide bearing of high-load combustion engines is not physically and thermally stable up to l80 centigrade. Different models show that after heating, all phases and structural components present on graph of equilibrium in given temperature are not created.

8

Effects of water intake layout along the wharf shoreline on ships

88%

Kong X.-w. , Ding L. , Liu H.-c. , Qu J. , Li X.-s.

Polish Maritime Research

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2019

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tom nr 4

165--171

EN

The construction of a water intake along the wharf shoreline can realise the intensive and comprehensive utilisation of the shoreline. However, since the water intake will increase the lateral flow at the wharf and also the hydrodynamic forces on ships, it will bring risks to ships mooring and leaving. The effects of the water intake on ships are studied using a physical model, numerical model and standard formulas. The results show that it leads to an increase of the hydrodynamic forces acting on the ship when the standard formulas are used to calculate the forces without considering the water level difference between the two sides of the ship. The results of the physical model are closer to the real situation. Measures that can effectively reduce the influence of the water intake on ships are proposed by increasing the distance between the wharf front and the front of the water intake as well as the depth of the water inlet windows.

9

Dehydration of no flotation size coal's slimes on the deck of high-frequency screen with multislopes area's working surface

88%

Eremejev I. , Polulyakh A. , Polulyakh D. , Grachyov O.

Teka Komisji Motoryzacji i Energetyki Rolnictwa

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2014

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tom 14

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nr 2

10

A physical model of separation process by means of jigs

88%

Surowiak A. , Brozek M.

Physicochemical Problems of Mineral Processing

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2016

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tom Vol. 52, iss. 1

228--243

EN

In the case of ideal separation of minerals, partition into products is conducted according to a specific partition feature which is, for instance, the density of raw material. Usually, enrichment in a jig is described by means of the particle density as a partition feature. However, the degree of particle loosening in the jig's bed is influenced by, among others, the particle free settling velocity. After some time of the pulsating movement duration, particle segregation along the vertical axis according to the settling velocity will occur. It can be said that the particle free settling velocity constitutes a feature characteristic of the feed heterogeneous in terms of physical and geometric properties in the jigging process. In the article on the basis of heuristic considerations, a physical model of the partition function (recovery of the i-th fraction), in which interactions between particles in the working bed of the jig are taken into account, is derived. A cause of the formation of the mechanism of particle dispersion around equilibrium layers is given and the accuracy of particle partition for a narrow size fraction in two variations, i.e. in conditions when a partition feature is, accordingly, the particle density and settling velocity, is calculated. These calculations allowed for the analysis of causes of process and inherent dispersion formation which takes place during the jigging process.

11

K matematicheskojj modeli razdelenija zernovykh smesejj po plotnosti cilindricheskimi rabochimi poverkhnostjami

75%

Bredikhin V. , Shevchenko V.

Motrol. Motoryzacja i Energetyka Rolnictwa

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2015

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tom 17

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nr 7

12

Labyrinth screw pump theory

75%

Andrenko P. , Lebedev A.

Motrol. Motoryzacja i Energetyka Rolnictwa

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2014

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tom 16

|

nr 6

13

Experimental study of the effect of rock blasting with various cutting forms for tunnel excavation using physical model tests

75%

An H. , Song Y. , Yang D. , An H. , Song Y. , Yang D.

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tom 67

|

nr 3

14

Modelling edutainment

75%

Tofil J.

Czasopismo Techniczne. Architektura

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2015

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tom Y. 112, iss. 9-A

367--373

EN

The paper elaborates on a certain way of describing an architectural space by means of a physical model, along with a project exercise realized as a part of the course in Descriptive Geometry which is an element of the program of the first year of studies in the Faculty of Architecture. The intent is to incorporate a component of entertainment to break out of the “rigid” and “dry” way of teaching this subject.

PL

Artykuł prezentuje sposób opisu przestrzeni architektonicznej, jakim jest model fizyczny w powiązaniu z wybranym ćwiczeniem projektowym realizowanym w ramach przedmiotu Geometria wykreślna prowadzonego podczas pierwszego semestru studiów na Wydziale Architektury. Ćwiczenie to jest próbą wprowadzenia elementu zabawy strukturą dla przełamania „sztywnego” programu nauczania przedmiotu.

15

Właściwości statyczne łożyska ślizgowego z panewką pływającą

75%

Mazurkow A.

Przegląd Mechaniczny

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2003

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tom nr 5

14-20

PL

W pracy przedstawiono model fizyczny i matematyczny łożyska ślizgowego z panewką pływającą, badania właściwości filmu smarnego przeprowadzono dla modelu adiabatycznego, stacjonarnych warunków pracy z uwzględnieniem temperatury i ciśnienia oleju zasilającego łożysko

EN

A physical and mathematical model of a slide bearing with a floating sleeve. Examination of the properties of the lubricarting film was made for an adiabatic model and stationary operating conditions including temperature and pressure of oil delivered to the bearing.

16

Utilisation d’un modele reduit pour l’etude precise des marees dans une mer littorale

75%

Le Provost C.

Oceanologia

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1978

|

tom 09

17

A mathematical model of the sprocket – tensioner and/or road - wheel - hub motor/generator for the intelligent main battle tank

75%

Fijałkowski B.

Journal of KONES

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2009

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tom Vol. 16, No. 1

125-136

EN

In the paper has been formulated a mathematical model of the sprocket-, tensioner- and/or road-wheel-hub motor/generator for the electrically-powered and mechatronically-controlled intelligent main battle tank (IMBT). In order to formulate a mathematical model of the sprocket-, tensioner- and/or road-wheel-hub AC-AC, AC-DC-AC or DC-AC/AC-DC macrocommutator magnetoelectrically-excited in-wheel-hub motor/generator, analogous to the mathematical model of the brushed DC-AC/AC-DC commutator IPM magnetoelectrically-excited motor/generator with a rotating DC-AC/AC-DC mechanoelectńcal commutator taking into consideration equations of unholonomic constraints of the AC-AC, AC-DC-AC or DC-AC/AC-DC commutator, a set of the second-order Euler-Lagrange differential equations ofdynamics in a matrix notationfor the AC commutatorless on-board generator can be written. After taking into account the equations of unholonomic constraints of the MCT or MOSFET AC-DC/DC-AC macrocommutator in the differential equations of dynamics one can be obtained differential equations of dynamics, establishing of a mathematical model of AC-DC/DC-AC macrocommutator magnetoelectrically excited in-wheel-hub generator/motor with the MCT or MOSFET application specific integrated matrixer (ASIM) AC-DC/DC-AC macrocommutator, acting as the electrical machine's MCT or MOSFET ASIM AC-DC rectifier/DC-AC inverter.

18

Działanie mechanizmów broni automatycznej z odprowadzeniem gazów po zatrzymaniu tłoka gazowego

75%

Pac M. , Torecki S.

Problemy Techniki Uzbrojenia

|

2011

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tom R. 40, z. 120

85--92

PL

W referacie przedstawiono model fizyczny i matematyczny działania mechanizmów broni automatycznej z odprowadzeniem gazów prochowych po zatrzymaniu tłoka gazowego. W modelu uwzględniono okresy charakterystyczne wynikające z wykresu cyklicznego działania automatyki rozpatrywanego układu. Powyższe modele zostały uzupełnione przykładem obliczeń dla parametrów geometrycznych demonstratorów technologii karabinków standardowych Modułowego Systemu Broni Strzeleckiej kalibru 5,56 mm (MSBS-5,56).

EN

Physical and mathematical models of gas operated weapon after gas piston detaining are presented in this paper. The phenomenon was divided into eight specific periods regarding cycle of operation. Moreover some simulations results complemented by examples of calculations for geometric parameters of the Module-based Firearm System (MSBS-5,56) assault rifle technology demonstrators are included.

19

ANAFIS and neural network for modeling and prediction of ship squat in shallow waters: a new approach

75%

Zeraatgar H. , Akbari Vakilabadi K. , Salmalian K. , Haghi A. K.

International Journal of Applied Mechanics and Engineering

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2011

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tom Vol. 16, no 1

211-231

EN

The reduction of the distance between ship floor and seabed, while the ship is moving forward, is called squat. In this research, squat is determined for vessels with Series-60 hull forms in various depths by experimental methods and then different numerical methods are employed for squat modeling. For this reason, a set of facilities for testing the ship movement in shallow waters is prepared. A series of models of the vessel is manufactured and many tests are carried out. The aim of the present study is to demonstrate the usefulness of an adaptive-network-based fuzzy inference system (ANFIS) for modeling and predicting the squat parameter for ships in shallow waters. It is also shown how dimensionless squat (S*) varies with the variation of important parameters, namely: block coefficient (CB), dimensionless distance between the seabed and ship floor […] and hydraulic Froude Number (Fnh). The results obtained through the ANFIS are also compared with those of a multiple linear regression and GMDH-type neural network with multi-layered feed forward back propagation algorithm. The results show that the ANFIS-based squat has higher predictability function than other numerical methods.

20

Study of multi-layer flow in coextrusion processes

75%

Levanichev V.

Teka Komisji Motoryzacji i Energetyki Rolnictwa

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2014

|

tom 14

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nr 1