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Abstract

Lighting of the workplaces has a large impact on safety, proper vision comfort and visual efficiency. The aim of this article is to present an analysis of the lighting of the workplaces of people working on scaffoldings. The researches were carried out on 23 frame-type facade scaffoldings. The scaffoldings were examined from March to October 2017. Due to the specificity of works performed on scaffoldings, the researches were carried out in accordance with an individually adapted research program. The study analyzed the illuminance at particular points and variability in the lighting uniformity in a given workspace. Analysis of the obtained results showed a large variability in illuminance in workplaces of people working on scaffoldings. The measured illuminance levels in the workspaces on the one hand were higher than the minimum illuminance levels defined by the construction site standards, but on the other hand, illuminance levels that may dazzle the employees were also recorded. The luminous intensity depended on the season, time of day, location of the scaffolding, as well as the presence of a protective net installed on the scaffolding, which reduced the occurrence of values that could lead to situations in which the worker could be dazzled. The protective net installed on the scaffolding also reduces the differences in lighting in the scaffolding workspace, improving the lighting conditions of the workplaces.
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Authors and Affiliations

Iwona Szer
1
ORCID: ORCID
Jacek Szer
1
ORCID: ORCID

  1. Lodz University of Technology, Department of Building Materials Physics and Sustainable Design, Politechniki 6, 90-924 Łódz, Poland
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Abstract

The paper presents analytical and numerical model calculation results of the temperature distribution along the thermal flow meter. Results show a very good conformity between numerical and analytical model. Apart from the calculation results the experimental investigations are presented. The author performed the test where a temperature of duct wall surface was measured. Therelation between mass flow rate in terms of the duct surface temperature difference was developed.
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Authors and Affiliations

Artur Cebula
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Abstract

Diagnostics and decomposition of atmospheric disturbances in a planar flow are considered in this work. The study examines a situation in which the stationary equilibrium temperature of a gas may depend on the vertical coordinate due to external forces. The relations connecting perturbations are analytically established. These perturbations specify acoustic and entropy modes in an arbitrary stratified gas affected by a constant mass force. The diagnostic relations link acoustic and entropy modes, and are independent of time. Hence, they provide an ability to decompose the total vector of perturbations into acoustic and non-acoustic (entropy) parts, and to establish the distribution of energy between the sound and entropy modes, uniquely at any instant. The total energy of a flow is hence determined in its parts which are connected with acoustic and entropy modes. The examples presented in this work consider the equilibrium temperature of a gas, which linearly depends on the vertical coordinate. Individual profiles of acoustic and entropy parts for some impulses are illustrated with plots.

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Authors and Affiliations

Sergey Leble
Anna Perelomova
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Abstract

This paper presents a new modified method for the synthesis of non-uniform linear antenna arrays. Based on the recently developed invasive weeds optimization technique (IWO), the modified invasive weeds optimization method (MIWO) uses the mutation process for the calculation of standard deviation (SD). Since the good choice of SD is particularly important in such algorithm, MIWO uses new values of this parameter to optimize the spacing between the array elements, which can improve the overall efficiency of the classical IWO method in terms of side lobe level (SLL) suppression and nulls control. Numerical examples are presented and compared to the existing array designs found in the literature, such as ant colony optimization (ACO), particle swarm optimization (PSO), and comprehensive learning PSO (CLPSO). Results show that MIWO method can be a good alternative in the design of non-uniform linear antenna array.
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Authors and Affiliations

El Hadi Kenane
Farid Djahli
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Abstract

This paper presents a novel low-complexity soft demapping algorithm for two-dimensional non-uniform spaced constellations (2D-NUCs) and massive order one-dimensional NUCs (1D-NUCs). NUCs have been implemented in a wide range of new broadcasting systems to approach the Shannon limit further, such as DVB-NGH, ATSC 3.0 and NGB-W. However, the soft demapping complexity is extreme due to the substantial distance calculations. In the proposed scheme, the demapping process is classified into four cases based on different quadrants. To deal with the complexity problem, four groups of reduced subsets in terms of the quadrant for each bit are separately calculated and stored in advance. Analysis and simulation prove that the proposed demapper only introduces a small penalty under 0.02dB with respect to Max-Log-MAP demapper, whereas a significant complexity reduction ranging from 68.75% to 88.54% is obtained.

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Authors and Affiliations

Chen Wang
Fang Wang
Mingqi Li
Jinfeng Tian
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Abstract

In this paper the authors present the test carried out to obtain the uniform velocity distribution at the outlet cross section of flow fan. In the investigations the inner flat vane mounted inside of the impeller has been applied. For various angular position of the inner vane, one obtained different flow structures as well as different velocity distributions. The analysis of the obtained results is presented in form of graphs shown in 10 figures, juxtaposing flow phenomena with velocity distributions. Numerical flow simulation with the use of Flo++ program based on the Finite Volume Method was carried out.

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Authors and Affiliations

Jolanta Stacharska-Targosz
Monika Chmielowiec
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Abstract

In this work, steady flow-field and heat transfer through a copper-water nanofluid around a rotating circular cylinder, dissipating uniform heat flux, with a constant non-dimensional rotation rate varying from 0 to 5 was investigated numerically using a finite-volume method for Reynolds numbers from the range 10–40. Furthermore, the range of nanoparticle volume fractions considered is 0–5%. The variation of the local and the average Nusselt numbers with Reynolds number, volume fractions, and rotation rate are presented for the range of conditions. The average Nusselt number is found to increase with increasing the nanoparticle volume fractions and decrease with increasing value of the rotation rate.

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Authors and Affiliations

Rafik Bouakkaz
Abded El Ouahed Ouali
Yacine Khelili
Salhi Faouzi
Ilyes Tiauiria
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Abstract

Simulation of wave propagation in the three-dimensional (3D) modeling of the vocal tract has shown significant promise for enhancing the accuracy of speech production. Recent 3D waveguide models of the vocal tract have been designed for better accuracy but require a lot of computational tasks. A high computational cost in these models leads to novel work in reducing the computational cost while retaining accuracy and performance. In the current work, we divide the geometry of the vocal tract into four equal symmetric parts with the introduction of two axial perpendicular planes, and the simulation is performed on only one part. A novel strategy is defined to implement symmetric conditions in the mesh. The complete standard 3D digital waveguide model is assumed as a benchmark model. The proposed model is compared with the benchmark model in terms of formant frequencies and efficiency. For the demonstration, the vowels /O/, /i/, /E/, /A/, and /u/ have been selected for the simulations. According to the results, the benchmark and current models are nearly identical in terms of frequency profiles and formant frequencies. Still the current model is three times more effective than the benchmark model.
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Authors and Affiliations

Tahir Mushtaq
1
Ahmad Kamran
1
Muhammad Zubair Akbar Qureshi
2
Zafar Iqbal
3

  1. Department of Mathematics, COMSATS University Islamabad, Vehari Campus, Vehari, Pakistan
  2. Department of Mathematics, Air University, Islamabad, Pakistan
  3. Department of Mathematics, Government Graduate College of Science, Multan, Pakistan
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Abstract

A computer model EUSS (Emission Uniformity on Sloping Surfaces) has been developed to design and evaluate the system capacity under operating conditions for drip irrigation system. And achieve the desired value of emission uniformity that is not significantly different according to the recommended values by applying it in field experiment located at Al- -Slahia city, Egypt. The model has the ability to design the system by all of the common design techniques and have ability to customize any of them.

EUSS model includes two main parts: crop water requirements, and hydraulic calculations of the system using metric unit system. It developed in graphical user interface of the programming language C-sharp (C#) by using Microsoft Visual Studio. The model database is containing the equations, tables and reference values to get more rapid and accurate results, and gives the opportunity for selecting some parameters such as: soil properties, characteristics of the corresponding crop, and climatic data. EUSS model allows the user to assume or set definite values, for example plot layout, land slopes and topography, the emitter characteristics and operating conditions.

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Bibliography

ALI M. 2016. Design approach to optimize pressurized irrigation systems in Egypt. M.Sc. Thesis. Helwan University. Mataria Faculty of Engineering, Mechanical Power Department pp. 113.
ALLEN R. 1999. SPRINKMOD – pressure and discharge simulation model for pressurized irrigation systems. 1. Model development and description. Irrigation Science. Vol. 18 p. 141–148.
ALLEN R.G., PEREIRA L.S., RAES D., SMITH M. 1998. Chapter 1. Introduction to evapotranspiration. In: Crop evapotranspiration – Guidelines for computing crop water requirements [online]. Food and Agriculture Organization of the United Nations (FAO). Irrigation and Drainage Paper 56. Rome. FAO. [Access 15.12.2019]. Available at: http://www.fao.org/3/X0490E/x0490e04.htm#evapotranspiration
ASAE 1999a. Design and installation of micro-irrigation systems. EP405.1 DEC98. In: ASAE Standards 1999: Standards Engineering Practices Data. St. Joseph. American Society of Agricultural Engineers p. 879–881.
ASAE 1999b. Field evaluation of micro-irrigation systems, EP458 DEC98. In: ASAE Standards 1999: Standards Engineering Practices Data. St. Joseph. American Society of Agricultural Engineers p. 922–923.
BREMERE I., KENNEDY M., STIKKER A., SCHIPPERS J. 2001. How water scarcity will affect the growth in the desalination market in the coming 25 years. Desalination. Vol. 138. Iss. 1–3 p. 7–15. DOI 10.1016/S0011-9164(01)00239-9.
EL-FELLALY S., SALEH E. 2004. Egypt’s experience with regard to water demand management in agriculture. [Eighth International Water Technology Conference, IWTC8]. [2004 Alexandria, Egypt].
FAO 2011. The state of the world’s land and water resources for food and agriculture. Managing systems at risk. Rome–London. Food and Agriculture Organization of the United Nations, Earthscan. ISBN 978-1-84971-327-6 pp. 285.
GU Z., QI Z., MA L., GUI D., XU J., FANG Q., YUAN S., FENG G. 2017. Development of an irrigation scheduling software based on model predicted crop water stress. Computers and Electronics in Agriculture. Vol. 143 p. 208–221.
HOFWEGEN P., SVENDSEN M. 2000. A vision of water for food and ruaral development: Final. [International Conference “World Water Forum”]. [17 March 2000 The Hague] pp. 82.
IRMAK S., ODHIAMBO L., KRANZ W., EISENHAUER D. 2011. Irrigation efficiency and uniformity, and crop water use efficiency [online]. Department of Biological Systems Engineering: Papers and Publications. University of Nebraska – Lincoln. [2011]. Available at: https://extensionpublications.unl.edu/assets/pdf/ec732.pdf
ISMAIL S., ELNESR M., ELASHRY R. 2000. Computer aided design of drip irrigation systems. Misr Journal of Agricultural Engineering. Vol. 18(2) p. 243–260. JAIN S. 2001. Development of design methodology and software for micro-irrigation sub-units. M.Sc. Thesis. Pantnagar. G. B. Pant University of Agriculture and Technology. Department of Irrigation and Drainage Engineering pp. 155.
JAMREY P.K., NIGAM G.K. 2018. Performance evaluation of drip irrigation systems. The Pharma Innovation Journal. Vol 7(1) p. 346–348.
KELLER J., BLIESNER R. 1990. Sprinkle and trickle irrigation. New York. Springer Science and Business Media. ISBN 9780442246457 pp. 652.
LAMM F., AYARS J., NAKAYAMA F. 2007. Microirrigation for crop production. Design, operation, and management. United Kingdom. Elsevier. ISBN 0-444-50607-1 pp. 642.
MAHROUS A., HANAFY M., BAKEER G., BAZARAA A. 2008. Computer program for predicting emission uniformity of odd-shaped sub-units in drip irrigation system. Misr Journal of Agricultural. Engineering. Irrigation and drainage. Vol. 25(4) p. 1240–1255.
MIRZAEI F., HATAMI M., MOUSAZADEH F. 2009. A simple model to estimate wetted soil volume from the trickle by use of the dimensional analysis technique. Advances in Water Resources and Hydraulic Engineering p. 345–352.
MOSTAFA E. 2004. Correction factor for friction head loss through lateral and Manifold. Eighth International Water Technology Conference IWTC8. Alexandria, Egypt p. 735–749.
PHILIPOVA N., NICHEVA O., KAZANDJIEV V., CHILIKOVA-LUBO¬MIROVA M. 2012. A computer program for drip irrigation system design for small plots. Journal of Theoretical and Applied Mechanics. Vol. 42. Iss. 4 p. 3–18. DOI 10.2478/v10254-012-0016-x.
PHOCAIDES A. 2001. Technical handbook on pressurized irrigation techniques. Rome. Food and Agriculture Organization of the United Nations (FAO). ISBN 9251045321 pp. 208.
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SWAMEE P., RATHIE P. 2005. Discussion of “Direct equations for hydraulic jump elements in rectangular horizontal channel”. Journal of Irrigation and Drainage Engineering. Vol. 131(3) p. 300–302. DOI 10.1061/(ASCE)0733-9437(2005)131:3 (298).
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USDA 2013. Micro-irrigation. Chapt. 7. National engineering handbook. Part 623. Irrigation [online]. United States Department of Agriculture. [Access 10.03.2020]. Available at: https://directives.sc.egov.usda.gov/OpenNonWebContent.aspx?content=34517.wba

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Authors and Affiliations

Wafaa Abo Zied
1
ORCID: ORCID
Mohammed Hanafy
1
Ehab Mostafa
1
ORCID: ORCID
Ahmed Abo Habssa
2

  1. Cairo University, Faculty of Agriculture, Agricultural Engineering Department, Gamaa Street 1, Giza, 12613, Egypt
  2. Helwan University, Mataria Faculty of Engineering, Mechanical Power Department, Helwan, Egypt
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Abstract

In this research work, high uniform CuFeS2 chalcopyrite with 20-40 nm particles were synthesized via a simple hydrothermal method. Different analysis were used to characterize the obtained product such as X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA). The photocatalytic activity of the product was investigated by degradation three different dyes namely acid brown, acid red and methylene blue. The results showed the synthesized CuFeS2 nanoparticles have high photocatalytic activity and can degrade the used dyes in large quantities.

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Authors and Affiliations

Mohammad Sabet
Kamran Mahdavi
Fahimeh Salmeh
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Abstract

In recent years, many scientific and industrial centres in the world developed a virtual reality systems or laboratories. The effect of user “immersion” into virtual reality in such systems is largely dependent on optical properties of the system. In this paper, problems of luminance distribution uniformity in CAVE-type virtual reality systems are analyzed. For better characterization of CAVE luminance nonuniformity corner and edge CAVE nonuniformity were introduced. Based on described CAVE-type virtual reality laboratory, named Immersive 3D Visualization Lab (I3DVL) just opened at the Gdansk University of Technology, luminance nonuniformity of the system is evaluated and discussed. Data collection of luminance distribution allows for software compensation of intensity distribution of individual images projected onto the screen (luminance non-uniformity minimization) in the further research.

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Authors and Affiliations

A. Mazikowski
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Abstract

The work deals with experimental and numerical thermodynamic analyses of cross-flow finned tube heat exchangers of the gas-liquid type. The aim of the work is to determine an impact of the gas non-uniform inlet on the heat exchangers performance. The measurements have been carried out on a special testing rig and own numerical code has been used for numerical simulations. Analysis of the experimental and numerical results has shown that the range of the non-uniform air inlet to the considered heat exchangers may be significant and it can significantly affect the heat exchanger efficiency.

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Authors and Affiliations

Tomasz Bury
Jan Składzień
Katarzyna Widziewicz
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Abstract

The work deals with the heat analysis of generalized Burgers nanofluid over a stretching sheet. The Rosseland approximation is used to model the non-linear thermal radiation and incorporated non-uniform heat source/sink effect. The governing equations reduced to a set of nonlinear ordinary differential equations under considering the suitable similarity transformations. The obtained ordinary differential equations equations are solved numerically by Runge-Kutta-Fehlberg order method. The effect of important parameters on velocity, temperature and concentration distributions are analyzed and discussed through the graphs. It reveals that temperature increases with the increase of radiation and heat source/sink parameter.
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Authors and Affiliations

Ganesh Kumar K.
B.J. Gireesha
G.K. Ramesh
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Abstract

The goal of this paper is to explore and to provide tools for the investigation of the problems of unit-length scheduling of incompatible jobs on uniform machines. We present two new algorithms that are a significant improvement over the known algorithms. The first one is Algorithm 2 which is 2-approximate for the problem Qm|pj  = 1, G = bisubquartic|Cmax. The second one is Algorithm 3 which is 4-approximate for the problem Qm|pj  = 1, G = bisubquarticCj, where m ∈ {2, 3, 4}. The theory behind the proposed algorithms is based on the properties of 2-coloring with maximal coloring width, and on the properties of ideal machine, an abstract machine that we introduce in this paper.

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Authors and Affiliations

T. Pikies
M. Kubale
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Abstract

Complex structures used in various engineering applications are made up of simple structural members like beams, plates and shells. The fundamental frequency is absolutely essential in determining the response of these structural elements subjected to the dynamic loads. However, for short beams, one has to consider the effect of shear deformation and rotary inertia in order to evaluate their fundamental linear frequencies. In this paper, the authors developed a Coupled Displacement Field method where the number of undetermined coefficients 2n existing in the classical Rayleigh-Ritz method are reduced to n, which significantly simplifies the procedure to obtain the analytical solution. This is accomplished by using a coupling equation derived from the static equilibrium of the shear flexible structural element. In this paper, the free vibration behaviour in terms of slenderness ratio and foundation parameters have been derived for the most practically used shear flexible uniform Timoshenko Hinged-Hinged, Clamped-Clamped beams resting on Pasternak foundation. The findings obtained by the present Coupled Displacement Field Method are compared with the existing literature wherever possible and the agreement is good.

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Bibliography

[1] C.F. Lü, C.W. Lim, and W.A. Yao. A new analytic symplectic elasticity approach for beams resting on Pasternak elastic foundations. Journal of Mechanics of Materials and Structures, 4(10):1741–1754, 2010. doi: 10.2140/jomms.2009.4.1741.
[2] C. Franciosi and A. Masi. Free vibrations of foundation beams on two-parameter elastic soil. Computers & Structures, 47(3):419–426, 1993. doi: 10.1016/0045-7949(93)90237-8.
[3] I. Caliò and A. Greco. Free vibrations of Timoshenko beam-columns on Pasternak foundations. Journal of Vibration and Control, 19(5):686–696, 2013. doi: 10.1177/1077546311433609.
[4] S. Lee, J.K. Kyu Jeong and J. Lee. Natural frequencies for flexural and torsional vibrations of beams on Pasternak foundation. Soils and Foundations, 54(6):1202–1211, 2014. doi: 10.1016/j.sandf.2014.11.013.
[5] M.A. De Rosa. Free vibrations of Timoshenko beams on two-parameter elastic foundation. Computers & Structures, 57(1):151–156, 1995. doi: 10.1016/0045-7949(94)00594-S.
[6] M.A. De Rosa and M.J. Maurizi. The influence of concentrated masses and Pasternak soil on the free vibrations of Euler beams—exact solution. Journal of Sound and Vibration, 212(4):573–581, 1998. doi: 10.1006/jsvi.1997.1424.
[7] M. Karkon and H. Karkon. New element formulation for free vibration analysis of Timoshenko beam on Pasternak elastic foundation. Asian Journal of Civil Engineering (BHRC), 17(4):427–442, 2016.
[8] K. Meera Saheb et al. Free vibration analysis of Timoshenko beams using Coupled Displacement Field Method. Journal of Structural Engineering, 34:233–236, 2007.
[9] M.T. Hassan and M. Nassar. Analysis of stressed Timoshenko beams on two parameter foundations. KSCE Journal of Civil Engineering, 19(1):173–179, 2015. doi: 10.1007/s12205-014-0278-8.
[10] N.D. Kien. Free vibration of prestress Timoshenko beams resting on elastic foundation. Vietnam Journal of Mechanics, 29(1):1–12, 2007. doi: 10.15625/0866-7136/29/1/5586.
[11] P. Obara. Vibrations and stability of Bernoulli-Euler and Timoshenko beams on two-parameter elastic foundation. Archives of Civil Engineering, 60(4):421–440, 2014. doi: 10.2478/ace-2014-0029.
[12] S.Y. Lee, Y.H. Kuo, and F.Y. Lin. Stability of a Timoshenko beam resting on a Winkler elastic foundation. Journal of Sound and Vibration, 153(2):193–202, 1992. doi: 10.1016/S0022-460X(05)80001-X.
[13] T.M. Wang and J.E. Stephens. Natural frequencies of Timoshenko beams on Pasternak foundations. Journal of Sound and Vibration, 51(2):149–155, 1977. doi: 10.1016/S0022-460X(77)80029-1.
[14] T.M. Wang and L.W. Gagnon. Vibrations of continuous Timoshenko beams on Winkler-Pasternak foundations. Journal of Sound and Vibration, 59(2):211–220, 1978. doi: 10.1016/0022-460X(78)90501-1.
[15] T. Yokoyama. Vibration analysis of Timoshenko beam-columns on two-parameter elastic foundations. Computers & Structures, 61(6):995–1007, 1996. doi: 10.1016/0045-7949(96)00107-1.
[16] T. Yokoyama. Parametric instability of Timoshenko beams resting on an elastic foundation. Computers & Structures, 28(2):207–216, 1988. doi: 10.1016/0045-7949(88)90041-7.
[17] W.Q. Chen, C.F. Lü, and Z.G. Bian. A mixed method for bending and free vibration of beams resting on a Pasternak elastic foundation. Applied Mathematical Modelling, 28(10):877–890, 2004. doi: 10.1016/j.apm.2004.04.001.
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Authors and Affiliations

Korabathina Rajesh
1
Koppanati Meera Saheb
1

  1. Jawaharlal Nehru Technological University Kakinada, Andhra Pradesh, India
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Abstract

The performance of majority engineering systems made of composite laminates can be improved by increasing strength to weight ratio. Variable thickness approach (VTA), in discrete form, used in this study is capable of finding minimum laminate thickness in one stage only, instead of two stage methodology defined by other researchers, with substantial accuracy for the given load conditions. This minimum required laminate thickness can be used by designers in multiple ways. Current study reveals that effectiveness of VTA in this regard depends on ply thickness increment value and number of plies. Maximum Stress theory, Tsai Wu theory and Tsai Hill theory are used as constraints, while ply angles, ply thicknesses and number of plies in discrete form are used as design variables in current simulation studies. Optimization is carried out using direct value coded genetic algorithm. The effect of design variables such as ply angles, ply thicknesses and number of plies in discrete form on optimum solution is investigated considering Uniform Thickness Approach (UTA) and Variable Thickness Approach (VTA) for various load cases.

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Authors and Affiliations

Nishant Shashikant Kulkarni
Vipin Kumar Tripathi
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Abstract

Affine discrete-time control periodic systems are considered. The problem of global asymptotic stabilization of the zero equilibrium of the closed-loop system by state feedback is studied. It is assumed that the free dynamic system has the Lyapunov stable zero equilibrium. The method for constructing a damping control is extended from time-invariant systems to time varying periodic affine discrete-time systems. By using this approach, sufficient conditions for uniform global asymptotic stabilization for those systems are obtained. Examples of using the obtained results are presented.
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Authors and Affiliations

Adam Czornik
1
Evgenii Makarov
2
Michał Niezabitowski
3
Svetlana Popova
4
Vasilii Zaitsev
4

  1. Faculty of Automatic Control, Electronics and Computer Science, Silesian University of Technology, 44-100 Gliwice, Poland
  2. Institute of Mathematics, National Academy of Sciencesof Belarus, 220072 Minsk, Belarus
  3. Faculty of Automatic Control, Electronics and Computer Science,Silesian University of Technology, 44-100 Gliwice, Poland
  4. Udmurt State University, 426034 Izhevsk, Russia
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Abstract

In this paper we deal with the problem of uniform exponential stabilization for a class of distributed bilinear parabolic systems with time delay in a Hilbert space by means of a bounded feedback control. The uniform exponential stabilization problem of such a system reduces to stabilizing only its projection on a suitable finite dimensional subspace. Furthermore, the stabilizing feedback control depends only on the state projection on the finite dimensional subspace. An explicit decay rate estimate of the stabilized state is given provided that a nonstandard weaker observability condition is satisfied. Illustrative examples for partial functional differential equations are displayed.
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Authors and Affiliations

Azzeddine Tsouli
1
Mostafa Ouarit
2

  1. Laboratory of Mathematics and Applications, ENSAM, Hassan II University of Casablanca, Morocco
  2. Laboratory of Fundamental and Applied Mathematics LAMFA, Faculty of Sciences Ain Chock, Hassan II University of Casablanca, Morocco
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Abstract

In this study, free and forced vibration responses of carbon nanotube reinforced uniform and tapered composite beams are investigated. The governing differential equations of motion of a carbon nanotube (CNT) reinforced uniform and tapered composite beams are presented in finite element formulation. The validity of the developed formulation is demonstrated by comparing the natural frequencies evaluated using present FEM with those of available in literature. Various parametric studies are also performed to investigate the effect of aspect ratio, percentage of CNT content, ply orientation, and boundary conditions on natural frequencies and mode shapes of a CNT reinforced composite beam. It was observed that the addition of carbon nanotube in fiber reinforced polymer composite (FRP) beam enhances the stiffness of the structure which consequently increases the natural frequencies and alters the mode shapes.

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Authors and Affiliations

Ananda Babu Arumugam
Vasudevan Rajamohan
Naresh Bandaru
Edwin Sudhagar P.
Surajkumar G. Kumbhar
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Abstract

The non-uniformity of temperature field distribution of long-span steel structure is proportional to the intensity of solar radiation. Based on the background of Guangzhou Baiyun Station large-span complex steel roof structure, this paper studies the non-uniformtemperature field distribution of large-span steel structure under the Summer Solstice daily radiation-thermal-fluid coupling action based on Star-ccm¸ finite element software, and uses Spa2000 software to analyze the stress and deformation of steel roof under temperature action. Combined with the on-site temperature monitoring, the maximum difference with the measured value is 2.5˚C compared with the numerical simulation results, which verifies the validity of the finite element simulation. The results show that: from 8:00, with the increase of solar altitude angle, the intensity of solar radiation increases, the temperature rises, and the temperature distribution of large-span steel structure becomes more and more non-uniform. From14:00 to18:00, the solar radiation weakens, and the temperature distribution tends to be uniform. Finally, reasonable construction suggestions and measures are proposed to reduce the adverse effects of temperature effects, which can provide theoretical references for the safe construction and normal operation of large-span steel structures located in the subtropics.
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Authors and Affiliations

Pengcheng Jiang
1
ORCID: ORCID

  1. Station Construction Command, China Railway Guangzhou Group Co., Ltd., Guangzhou, Guangdong, China
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Abstract

A mathematical method for nonlinear surrogate synthesis of frame surface eddy current probes providing a uniform eddy current density distribution in the testing object area is proposed. A metamodel of a frame movable eddy-current probe with a planar excitation system structure, used in the algorithm for surrogate optimal synthesis was created. The examples of a nonlinear synthesis of excitation systems with the application of the modern metaheuristic stochastic algorithms for finding the global extremum are considered. The numerical findings of the problem analyses are presented. The efficiency of the synthesized excitation structures was demonstrated on the basis of the eddy current density distribution graphs on the surface of the control zone of the object in comparison with classical analogues.
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Bibliography

[1] Rosado, L. S., Gonzalez, J. C., Santos, T. G., Ramos, P. M., & Pieda, M. (2013). Geometric optimization of a differential planar eddy currents probe for non-destructive testing. Sensors and Actuators A: Physical., 197, 96–105. https://doi.org/10.1016/j.sna.2013.04.010
[2] Su, Z., Efremov, A., Safdarnejad, M., Tamburrino, A., Udpa, L., & Udpa, S. (2015). Optimization of coil design for near uniform interrogating field generation. AIP Conference Proceedings, 1650, 405–413. https://doi.org/10.1063/1.4914636
[3] Su, Z.,Ye, C., Tamburrino, A., Udpa, L.,&Udpa, S. (2016). Optimization of coil design for eddy current testing of multi-layer structures. International Journal of Applied Electromagnetics and Mechanics, 52(1–2), 315–322. https://doi.org/10.3233/JAE-162030
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Authors and Affiliations

Volodymyr Ya. Halchenko
1
Ruslana Trembovetska
1
ORCID: ORCID
Volodymyr Tychkov
1
ORCID: ORCID

  1. Cherkasy State Technological University, Instrumentation, Mechatronics and Computer Technologies Department, Blvd. Shevchenka, 460, 18006, Cherkasy, Ukraine
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Abstract

Non−uniformity noise, it was, it is, and it will probably be one of the most non−desired attached companion of the infrared focal plane array (IRFPA) data. We present a higher order filter where the key advantage is based in its capacity to estimates the detection parameters and thus to compensate it for fixed pattern noise, as an enhancement of Constant Statistics (CS) theory. This paper shows a technique to improve the convergence in accelerated way for CS (AACS: Acceleration Algorithm for Constant Statistics). The effectiveness of this method is demonstrated by using simulated infrared video sequences and several real infrared video sequences obtained using two infrared cameras

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Authors and Affiliations

A.G. Jara-Chavez
F.O. Torres-Vicencio

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