scholarly journals Studying the impact of amendments in the Polish guidelines on the values of basic geometric parameters of railway lines

2019 ◽  
Vol 20 (1-2) ◽  
pp. 466-470
Author(s):  
Dorota Błaszkiewicz ◽  
Paulina Szabłowska
Keyword(s):  
Geometric Parameters ◽  
Geometric Systems ◽  
Basic Parameters ◽  
The Impact

The article discusses changes in domestic regulations related to de-signing geometric systems of railway lines. Also, a model of calculating the basic parameters of geometric systems performed for three different (extreme) design examples was presented. The calculations were performed according to two guidelines

Solow economy model

2019 ◽  
pp. 150-157
Author(s):  
Oleksandr Synenko ◽  
Kateryna Yarema ◽  
Yuliia Bezsmertna
Keyword(s):  
Economic Growth ◽  
Regression Analysis ◽  
Solow Model ◽  
Economy Model ◽  
Accelerated Depreciation ◽  
Basic Parameters ◽  
The Subject ◽  
Investment Process ◽  
The Impact ◽  
Model Algorithm

The subject of the research is the approach to the possibility of using the Solow model to perform the regression analysis on the example of the Ukrainian economy model. The purpose of writing this article is to investigate the notion of regres- sion analysis, Solow’s economy model, algorithm for performing regression analy- sis on the example of Ukraine’s economy model. This model can be adapted for the economy of enterprises. Methodology. The research methodology is system-struc- tural and comparative analyzes (to study the structure of GDP); monograph (when studying methods of regression analysis on the example of the Ukrainian economy); economic analysis (when assessing the impact of factors on Ukraine’s GDP). The scientific novelty consists the features of the use of the Solow model on the ex- ample of Ukrainian economy are determined. An algorithm for calculating the basic parameters of a model using the Excel application package is disclosed. The main recommendations on the development of the national economy and economic growth through the use of macroeconomic instruments are given. Conclusions. The use of the Solow model enables forecasting and analysis. The results obtained re- vealed the problem of low resource return of capital as a resource, along with the means of macroeconomic regulation of the investment process, using which can improve the situation. A special place in these funds belongs to the accelerated depreciation and interest rate policies.

Experimental Investigation and Characterization of the Rotating Stall in a High Pressure Centrifugal Compressor: Part II — Influence of Diffuser Geometry on Stage Performance

2002 ◽  
Author(s):  
G. Ferrara ◽  
L. Ferrari ◽  
C. P. Mengoni ◽  
M. De Lucia ◽  
L. Baldassarre
Keyword(s):  
Experimental Tests ◽  
Rotating Stall ◽  
Geometric Parameters ◽  
Flow Coefficient ◽  
Low Flow ◽  
Main Task ◽  
Stage Performance ◽  
The Impact ◽  
Prediction Criteria

Extensive research on centrifugal compressors has been planned. The main task of the research is to improve present prediction criteria coming from the literature with particular attention to low flow coefficient impellers (low width to radius ratios) where they are no more valid. Very little data has been published for this kind of stages, especially for the last stage configuration (with discharge volute). Many experimental tests have been planned to investigate different configurations. A simulated stage with a backward channel upstream, a 2D impeller with a vaneless diffuser and a constant cross section volute downstream constitute the basic configuration. Several diffuser types with different widths, pinch shapes and diffusion ratios were tested. The effect of geometric parameters on stage stability has been discussed inside part I of the present work; the purpose of this part of the work is to illustrate the effect of the same geometric parameters on stage performance and to quantify the impact of stability improvements on stage losses.

scholarly journals The impact of haulroad geometric parameters on open pit mine strip ratio

2019 ◽  
Vol 72 (1 suppl 1) ◽  
pp. 25-31
Author(s):  
Douglas Alexandre Gonçalves Alegre ◽  
Rodrigo de Lemos Peroni ◽  
Eduardo da Rosa Aquino
Keyword(s):  
Open Pit Mine ◽  
Geometric Parameters ◽  
Open Pit ◽  
The Impact

scholarly journals Towards a Better Understanding of Microbial Community Dynamics through High-Throughput Cultivation and Data Integration

mSystems ◽  
2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Karoline Faust
Keyword(s):  
Microbial Community ◽  
High Throughput ◽  
Community Dynamics ◽  
Analysis Software ◽  
High Quality ◽  
Microbial Community Dynamics ◽  
Lack Of Control ◽  
Basic Parameters ◽  
Community Data ◽  
The Impact

ABSTRACT The investigation of microbial community dynamics is hampered by low resolution, a lack of control, and a small number of replicates. These deficiencies can be tackled with defined communities grown under well-controlled conditions in high-throughput automated cultivation devices. Besides delivering high-quality microbial community data, automated cultivation will also ease measurement of the basic parameters needed to parameterize mathematical models of microbial communities. Better experimental data will allow revisiting classical ecological questions, such as the impact of community structure on dynamics. In addition, such data will allow validation and comparison of community models and benchmarking of microbial data analysis software. In summary, high-throughput automated cultivation will lead to a deeper understanding of microbial community dynamics through better models and software.

On the Effective Properties of 3D Metamaterials

2016 ◽  
Author(s):  
Mohamed Abdelhamid ◽  
Aleksander Czekanski
Keyword(s):  
Elastic Modulus ◽  
Effective Properties ◽  
Lattice Structure ◽  
Surface Elasticity ◽  
Geometric Parameters ◽  
Stiffness Tensor ◽  
Loading Direction ◽  
Octet Truss ◽  
The Impact ◽  
Effective Mechanical Properties

A continuum-based model is developed for the octet-truss unit cell in order to describe the effective mechanical properties (elastic modulus) of the lattice structure. This model is to include different geometric parameters that impact the structural effects; these parameters are: lattice angle, loading direction, thickness to diameter ratio, diameter to length ratio, and ellipticity. All these geometric parameters are included in the stiffness matrix, and the impact of each parameter on the stiffness tensor is investigated. Specifically, the effect of the lattice angle on the elastic moduli is discussed, and the loading direction of the highest elastic modulus is investigated for different lattice angles. Furthermore, the Gurtin-Murdoch model of surface elasticity is used to include the size effect in the stiffness tensor, as well as anisotropy of this model is investigated.

Parametric Experimental and Numerical Study of LP Diffuser and Exhaust Hoods

2016 ◽  
Author(s):  
Derek Taylor ◽  
Gurnam Singh ◽  
Phil Hemsley ◽  
Martin Claridge
Keyword(s):  
Numerical Study ◽  
Design Guidelines ◽  
Geometric Parameters ◽  
Design Tools ◽  
Steam Turbines ◽  
Exhaust Hood ◽  
Geometric Configurations ◽  
Last Stage ◽  
Lp Turbine ◽  
The Impact

The design of an effective diffuser for a given last stage blade of an LP turbine is known to be highly dependent on the size and shape of the exhaust hood in which it is located. For retrofit steam turbines in particular, where a new last stage blade and diffuser are fitted into an existing exhaust hood, the shapes and sizes of the exhaust box have been seen to vary significantly from one contract to the next. An experimental parametric study of diffuser lips and exhaust hood configurations has been run on a model test turbine rig at GE Power to investigate the impact of various geometric parameters on the performance of the diffusers. Improved testing and post-processing methodologies means the diffuser performance has been obtained for a greater number of geometric configurations than was previously typically possible. The results of these experiments are compared with numerical calculations and confirm the accuracy of the standard in-house diffuser design tools. Key geometric parameters are identified from the test data and used to generate improved diffuser design guidelines.

Continuum Aeroelastic Model and Flutter Analysis for a Variable-Span Morphing Wing

2013 ◽  
Vol 300-301 ◽  
pp. 1136-1143 ◽  
Author(s):  
Ren Huang ◽  
Zhi Ping Qiu ◽  
Xiao Jun Wang
Keyword(s):  
Reduced Order ◽  
Spatial Span ◽  
Aeroelastic Model ◽  
Flutter Analysis ◽  
Basic Parameters ◽  
Variable Span ◽  
The Time Domain ◽  
The Galerkin Method ◽  
The Impact ◽  
Euler Bernoulli Beam

A linear aeroelastic continuum model for a variable-span wing is developed. Considering the fixed inboard part and the movable outboard part of the wing, a stepped Euler-Bernoulli beam with three jumped discontinuities in its spatial span is used for structural modeling. The dynamic analysis of stepped beam is introduced by a dimensionless form. The time-domain aerodynamic forces are calculated by a reduced-order unsteady vortex lattice model. Then the first-order state-space aeroelastic formulations are built by using the Galerkin method. The impact of the different wing configurations is of particular interest for understanding the fundamental aeroelastic behavior of variable-span wing. To clarify the implementation of the proposed method, a simple variable-span wing with the basic parameters of the Goland wing is studied, and numerical simulations are provided to demonstrate the flutter speeds and frequencies for different wing configurations.

Effects of Manufacturing Noise on Microturbine Centrifugal Impeller Performance

2012 ◽  
Author(s):  
A. Javed ◽  
R. Pecnik ◽  
M. Olivero ◽  
J. P. van Buijtenen
Keyword(s):  
Performance Analysis ◽  
Three Dimensional ◽  
Geometric Parameters ◽  
Tip Clearance ◽  
Centrifugal Impeller ◽  
Analysis Tool ◽  
Modeling Tools ◽  
Output Performance ◽  
1D Model ◽  
The Impact

This paper presents a study on a small centrifugal impeller for microturbine application from a manufacturing perspective. The aim is to analyze the impact of geometric deviations on part performance using adequate performance modeling tools and statistical methods. A one-dimensional (1D) performance analysis tool has been developed in-house derived from the meanline and two-zone modeling methods. The 1D model has proved to be a simple and computationally inexpensive tool for having a quick performance analysis of the impeller using basic geometric information extracted from part drawings. For the sensitivity analysis, a total of eight input geometric parameters including radii, tip-clearance and blade angles have been varied individually within specific limits in the 1D tool for classifying their influence on the output performance. Since the 1D model is a simplified version of a much complex three-dimensional (3D) model, a commercial computational fluid dynamics (CFD) tool has been used to provide a comparison with the 1D model and scrutinize the effects of such deviations on the fluid behavior inside the impeller passage at a detailed level. For uncertainty quantification, Monte Carlo simulation has been performed using the 1D model to assess the variability of overall impeller output performance to simultaneous random deviations in the input geometric parameters. The study is useful to evaluate the possibility of designing gas turbine parts for manufacturability and superior production cost-effectiveness.

The Impact of Browsing Animals on the Stand Dynamics of Monotypic Mountain Beech (Nothofagus solandri) Forests in Canterbury, New Zealand

1994 ◽  
Vol 42 (2) ◽  
pp. 113 ◽  
Author(s):  
GT Jane
Keyword(s):  
New Zealand ◽  
Cervus Elaphus ◽  
Basal Area ◽  
Stand Density ◽  
Natural Disturbance ◽  
Basic Relationship ◽  
Basic Parameters ◽  
The 1960S ◽  
Logarithmic Relationship ◽  
The Impact

Mountain beech is frequently the sole canopy species in the montane forests of Canterbury, New Zealand and often the only significant tree or shrub present over large areas and this allows examination of a very simple ecosystem. Data from remeasurement of over 400 permanent quadrats in six areas are examined to elucidate the impact of browsing animals on natural processes. The changes in basic parameters such as stand density and basal area over a decade form consistent patterns in both visual and statistical techniques and this allows identification of important quadrats for detailed study. The basic relationship between density and basal area follows well an established semi-logarithmic relationship, even in decade by decade changes on individual quadrats. Deviations in this pattern can be related to natural disturbance events. The impact of browsing animals, mainly red deer (Cervus elaphus) varied between the different areas. Although numbers peaked in the 1930s and 1940s and declined through commercial hunting in the 1960s-1980s, the impact on the vegetation remains and will persist for many decades.

scholarly journals Influence Of Nanoparticles Diameter On Structural Properties Of Magnetic Fluid In Magnetic Field

2015 ◽  
Vol 66 (4) ◽  
pp. 231-234 ◽  
Author(s):  
Jozef Kúdelčík ◽  
Peter Bury ◽  
Štefan Hardoň ◽  
Peter Kopčanský ◽  
Milan Timko
Keyword(s):  
Magnetic Field ◽  
Structural Changes ◽  
Magnetic Fluids ◽  
Continuous Change ◽  
Acoustic Attenuation ◽  
Nanoparticle Diameter ◽  
Carrier Liquid ◽  
Basic Parameters ◽  
Transformer Oils ◽  
The Impact

AbstractThe properties of magnetic fluids depend on the nanoparticle diameter, their concentration and the carrier liquid. The structural changes in magnetic fluids with different nanoparticle diameter based on transformer oils TECHNOL and MOGUL under the effect of a magnetic field and temperature were studied by acoustic spectroscopy. At a linear and jump changes of the magnetic field at various temperatures a continuous change was observed of acoustic attenuation caused by aggregation of the magnetic nanoparticles to structures. From the anisotropy of acoustic attenuation and using the Taketomi theory the basic parameters of the structures are calculated and the impact of nanoparticle diameters on the size of structures is confirmed.

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