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1. Criticism study of J-Shaped darrieus wind turbine: Performance evaluation and noise generation assessment

Author:
Mohamed, M.H.
Source:
Energy 2019 v.177 pp. 367-385
ISSN:
0360-5442
Subject:
equations,   etc   ; aerodynamics; wind turbines;     Show all 3 Subjects
Abstract:
... Vertical Axis Wind Turbines (VAWTs) are suitable for use in populated areas. The main parameter of the design of this type of the wind turbine is the cross sectional profile of the turbine blade. Additionally, the turbine performance and the generated aerodynamic noise of the VAWTs are critical issues that could limit the spreading of these turbines especially in the residential zones. In the last ...
DOI:
10.1016/j.energy.2019.04.102

2. Water surface topology of supercritical junction flow

Author:
Rak, Gašper; Hočevar, Marko; Steinman, Franci
Source:
Vodohospodársky časopis 2019 v.67 no.2 pp. 163-170
ISSN:
0042-790X
Subject:
equations,   etc   ; engineering; hydrodynamics; topology;     Show all 4 Subjects
Abstract:
... The complexity of flow conditions at junctions amplifies significantly with supercritical flow. It is a pronounced three-dimensional two-phased flow phenomenon, where standing waves with non-stationary water surface are formed. To analyse the hydrodynamic conditions at an asymmetric right-angled junction with incoming supercritical flows at Froude numbers between 2 and 12, an experimental approach ...
DOI:
10.2478/johh-2018-0042

3. A normal contact force approach for viscoelastic spheres of the same material

Author:
Jian, B.; Hu, G.M.; Fang, Z.Q.; Zhou, H.J.; Xia, R.
Source:
Powder technology 2019 v.350 pp. 51-61
ISSN:
0032-5910
Subject:
equations,   etc   ; powders; viscoelasticity; viscosity;     Show all 4 Subjects
Abstract:
... This paper presents a normal contact force approach for viscoelastic spheres of the same material based on the theory of viscoelasticity. The approach treats the normal contact force as an elastic component superposed with a dissipative component based on which to derive a reduced expression, and is numerically analyzed for the viscoelastic spheres modelled by the standard linear solid with the si ...
DOI:
10.1016/j.powtec.2019.03.034

4. Boundary layer development over non-uniform sand rough bed channel

Author:
Sharma, Anurag; Kumar, Bimlesh
Source:
ISH journal of hydraulic engineering 2019 v.25 no.2 pp. 162-169
ISSN:
2164-3040
Subject:
equations,   etc   ; sand; seepage;     Show all 3 Subjects
Abstract:
... Experimental investigations were carried out to investigate the development of boundary layer in non-uniform sand bed channels with and without seepage. Steady flows over non-uniform sand bed channel were simulated experimentally with downward seepage applied through the boundary. Velocity measurements were made at 12 different sections along the channel mid-section for no seepage and seepage flow ...
DOI:
10.1080/09715010.2017.1391133

5. Gradually varied flow profile based on adaptive pattern

Author:
Jahandar Malekabadi, Mohammad; Kalateh, Farhoud
Source:
ISH journal of hydraulic engineering 2019 v.25 no.2 pp. 223-231
ISSN:
2164-3040
Subject:
equations,   etc   ; accuracy; water flow;     Show all 3 Subjects
Abstract:
... The basic equation of gradually varied flow (GVF) describes gradual changes in its water surface elevation. One of the challenges of numerical integration is determining the appropriate integration spatial step size. In this study, the water surface elevations in GVF are calculated by adaptive Runge–Kutta method and adaptive Newton–Raphson method. The steps are calculated using error estimation du ...
DOI:
10.1080/09715010.2017.1408035

6. Experimental study and modelling of the ventilation power and maximum temperature of low-pressure steam turbine last stages at low load

Author:
Mambro, Antonio; Congiu, Francesco; Galloni, Enzo; Canale, Laura
Source:
Applied energy 2019 v.241 pp. 59-72
ISSN:
0306-2619
Subject:
equations,   etc   ; models; temperature; turbines;     Show all 4 Subjects
Abstract:
... Experimental investigations on the behavior of a low-pressure turbine operating at low volume flow have been carried out. Detailed analysis of the measurements reveal a series of macroscopic correlations useful for both understanding and modelling the whole low volume flow phenomenon. A novel concept of blade saturation temperature has been introduced, while a non-dimensional group has been identi ...
DOI:
10.1016/j.apenergy.2019.03.003

7. A general framework for quantile estimation with incomplete data

Author:
Han, Peisong; Kong, Linglong; Zhao, Jiwei; Zhou, Xingcai
Source:
Journal of the Royal Statistical Society 2019 v.81 no.2 pp. 305-333
ISSN:
1369-7412
Subject:
equations,   etc   ; models; probability;     Show all 3 Subjects
Abstract:
... Quantile estimation has attracted significant research interest in recent years. However, there has been only a limited literature on quantile estimation in the presence of incomplete data. We propose a general framework to address this problem. Our framework combines the two widely adopted approaches for missing data analysis, the imputation approach and the inverse probability weighting approach ...
DOI:
10.1111/rssb.12309

8. Clustering functional data into groups by using projections

Author:
Delaigle, Aurore; Hall, Peter; Pham, Tung
Source:
Journal of the Royal Statistical Society 2019 v.81 no.2 pp. 271-304
ISSN:
1369-7412
Subject:
equations,   etc   ; algorithms; models; statistics;     Show all 4 Subjects
Abstract:
... We show that, in the functional data context, by appropriately exploiting the functional nature of the data, it is possible to cluster the observations asymptotically perfectly. We demonstrate that this level of performance can sometimes be achieved by the k‐means algorithm as long as the data are projected on a carefully chosen finite dimensional space. In general, the notion of an ideal cluster ...
DOI:
10.1111/rssb.12310

9. Construction of row–column factorial designs

Author:
Godolphin, J. D.
Source:
Journal of the Royal Statistical Society 2019 v.81 no.2 pp. 335-360
ISSN:
1369-7412
Subject:
equations,   etc   ; models; statistics;     Show all 3 Subjects
Abstract:
... The arrangement of 2ⁿ‐factorials in row–column designs to estimate main effects and two‐factor interactions is investigated. Single‐replicate constructions are given which enable estimation of all main effects and maximize the number of estimable two‐factor interactions. Constructions and guidance are given for multireplicate designs in single arrays and in multiple arrays. Consideration is given ...
DOI:
10.1111/rssb.12305

10. Analysis strategy for multi-criteria optimization: Application to inter-seasonal solar heat storage for residential building needs

Author:
Launay, S.; Kadoch, B.; Le Métayer, O.; Parrado, C.
Source:
Energy 2019 v.171 pp. 419-434
ISSN:
0360-5442
Subject:
equations,   etc   ; energy; heat; models;     Show all 4 Subjects
Abstract:
... As energetic systems become more and more complex, it is necessary to develop strategies for analyzing the influence of the parameters as well as their couplings. This approach is even unavoidable when the optimization procedure is based on multi-criteria. In the present work, we propose an analysis strategy for multi-criteria optimization applied to inter-seasonal solar heat storage for residenti ...
DOI:
10.1016/j.energy.2018.12.181

11. Apparent efficiency of serially coupled columns in gradient elution liquid chromatography: Extension to the combination of any column formats

Author:
Codesido, Santiago; Rudaz, Serge; Guillarme, Davy; Horváth, Krisztián; Fekete, Szabolcs
Source:
Journal of chromatography 2019 v.1588 pp. 159-162
ISSN:
0021-9673
Subject:
equations,   etc   ; liquid chromatography; models;     Show all 3 Subjects
Abstract:
... It was shown earlier that in serially coupled column systems, not only retention (selectivity) but peak width as well can change and the apparent peak width depends on the order of the columns. A generic equation has been developed to describe the apparent efficiency of serially coupled columns in gradient elution liquid chromatography mode. In a previous work, the theoretical basis for a two-colu ...
DOI:
10.1016/j.chroma.2018.12.037

12. Solution for short-term hydrothermal scheduling with a logarithmic size mixed-integer linear programming formulation

Author:
Jian, Jinbao; Pan, Shanshan; Yang, Linfeng
Source:
Energy 2019 v.171 pp. 770-784
ISSN:
0360-5442
Subject:
equations,   etc   ; energy; linear programming;     Show all 3 Subjects
Abstract:
... Short-term hydrothermal scheduling issue is usually hard to tackle on account of its highly non-convex and non-differentiable characteristics. A popular strategy for handling these difficulties is to reformulate the issue by various linearization techniques. However, in this process, a fairly large number of continuous/binary variables and constraints will be introduced, which may result in a heav ...
DOI:
10.1016/j.energy.2019.01.038

13. Dephasing in a Molecular Junction Viewed from a Time-Dependent and a Time-Independent Perspective

Author:
Rahman, Hasan; Karasch, Patrick; Ryndyk, Dmitry A.; Frauenheim, Thomas; Kleinekathöfer, Ulrich
Source:
Journal of physical chemistry 2019 v.123 no.14 pp. 9590-9599
ISSN:
1932-7455
Subject:
equations,   etc   ; models; physical chemistry;     Show all 3 Subjects
Abstract:
... The current through a molecular junction can be determined numerically in a multitude of ways. Some of these methods like the Landauer scheme are only valid for coherent transport and the steady state regime while other schemes are able to treat time-dependent electronic currents across molecular junctions subject to fluctuating environments. In time-independent formalisms, the effect of thermal e ...
DOI:
10.1021/acs.jpcc.9b00955

14. Polydispersity Effects on Interpenetration in Compressed Brushes

Author:
Klushin, Leonid I.; Skvortsov, Alexander M.; Qi, Shuanhu; Kreer, Torsten; Schmid, Friederike
Source:
Macromolecules 2019 v.52 no.4 pp. 1810-1820
ISSN:
1520-5835
Subject:
equations,   etc   ; polymers; thermal energy;     Show all 3 Subjects
Abstract:
... We study the effect of polydispersity on the compression and interpenetration properties of two opposing polymer brushes by numerical self-consistent field approach and by analytical theory. Polydispersity is represented by an experimentally relevant Schulz–Zimm chain-length distribution. We focus on three different polydispersities representing sharp, moderate, and extremely wide chain length dis ...
DOI:
10.1021/acs.macromol.8b02361

15. An omnibus non‐parametric test of equality in distribution for unknown functions

Author:
Luedtke, Alex; Carone, Marco; van der Laan, Mark J.
Source:
Journal of the Royal Statistical Society 2019 v.81 no.1 pp. 75-99
ISSN:
1369-7412
Subject:
equations,   etc   ; models; statistics;     Show all 3 Subjects
Abstract:
... We present a novel family of non‐parametric omnibus tests of the hypothesis that two unknown but estimable functions are equal in distribution when applied to the observed data structure. We developed these tests, which represent a generalization of the maximum mean discrepancy tests described by Gretton and colleagues, using recent developments from the higher order pathwise differentiability lit ...
DOI:
10.1111/rssb.12299

16. On cross‐validation for sparse reduced rank regression

Author:
She, Yiyuan; Tran, Hoang
Source:
Journal of the Royal Statistical Society 2019 v.81 no.1 pp. 145-161
ISSN:
1369-7412
Subject:
equations,   etc   ; models; shrinkage; statistics;     Show all 4 Subjects
Abstract:
... In high dimensional data analysis, regularization methods pursuing sparsity and/or low rank have received much attention recently. To provide a proper amount of shrinkage, it is typical to use a grid search and a model comparison criterion to find the optimal regularization parameters. However, we show that fixing the parameters across all folds may result in an inconsistency issue, and it is more ...
DOI:
10.1111/rssb.12295

17. Effect of different discretizations on the numerical solution of 2D aggregation population balance equation

Author:
Singh, Mehakpreet; Vuik, Kees; Kaur, Gurmeet; Bart, Hans-Jörg
Source:
Powder technology 2019 v.342 pp. 972-984
ISSN:
0032-5910
Subject:
equations,   etc   ; data analysis; powders;     Show all 3 Subjects
Abstract:
... This work is concerned with the assessment of the various discretizations used to obtain the numerical solutions of the bivariate aggregation population balance equation. It was illustrated in the literature that the accuracy and the efficiency of the numerical approximations is majorly controlled by the directionality and orientation of the grid selected for the domain discretization [4,6,35]. Th ...
DOI:
10.1016/j.powtec.2018.10.028

18. Study of the column efficiency using gradient elution based on Van Deemter plots

Author:
Alvarez-Segura, T.; Cabo-Calvet, E.; Baeza-Baeza, J.J.; García-Alvarez-Coque, M.C.
Source:
Journal of chromatography 2019 v.1584 pp. 126-134
ISSN:
0021-9673
Subject:
equations,   etc   ; chromatography; sulfonamides; uncertainty;     Show all 4 Subjects
Abstract:
... Performance of chromatographic columns is of major importance in the development of more efficient separation methods. So far, a common practice is to study the column behavior in isocratic elution by modifying the flow rate and fitting the theoretical plate height values versus the mobile phase linear velocity, according to the Van Deemter equation. In this work, an approach is presented to exten ...
DOI:
10.1016/j.chroma.2018.11.042

19. A comparison of search strategies to design the cokriging neighborhood for predicting coregionalized variables

Author:
Madani, Nasser; Emery, Xavier
Source:
Stochastic environmental research and risk assessment 2019 v.33 no.1 pp. 183-199
ISSN:
1436-3240
Subject:
equations,   etc   ; models; prediction; variance;     Show all 4 Subjects
Abstract:
... Cokriging allows predicting coregionalized variables from sampling information, by considering their spatial joint dependence structure. When secondary covariates are available exhaustively, solving the cokriging equations may become prohibitive, which motivates the use of a moving search neighborhood to select a subset of data, based on their closeness to the target location and the screen effect ...
DOI:
10.1007/s00477-018-1578-1

20. Correction to: Analysis of swale factors implicated in pollutant removal efficiency using a swale database

Author:
Fardel, Alexandre; Peyneau, Pierre-Emmanuel; Béchet, Béatrice; Lakel, Abdelkader; Rodriguez, Fabrice
Source:
Environmental science and pollution research international 2019 v.26 no.2 pp. 1303
ISSN:
0944-1344
Subject:
equations,   etc   ; databases; pollution control;     Show all 3 Subjects
Abstract:
... The original publication of this paper contains an error. Correct presentation of Equation 1 is presented in this paper. ...
DOI:
10.1007/s11356-018-3846-5