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Abstract

The article introduces an innovative approch for the inspection challenge that represents a generalization of the classical Traveling Salesman Problem. Its priciple idea is to visit continuous areas (circles) in a way, that minimizes travelled distance. In practice, the problem can be defined as an issue of scheduling unmanned aerial vehicle which has discrete-continuous nature. In order to solve this problem the use of local search algorithms is proposed.

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Authors and Affiliations

Radosław Grymin
Wojciech Bożejko
Zenon Chaczko
Jarosław Pempera
Mieczysław Wodecki
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Abstract

The (Zn) – single crystal strengthened by the E = (Zn) + Zn16Ti eutectic precipitate is subjected to directional growth by the Bridgman’s system and current analysis. Experimentally, the strengthening layers (stripes) are generated periodically in the (Zn) – single crystal as a result of the cyclical course of precipitation which accompanies the directional solidification. These layers evince diversified eutectic morphologies like irregular rods, regular lamellae, and regular rods. The L – shape rods of the Zn16Ti – intermetallic compound appear within the first range of the growth rates when the irregular eutectic structure is formed. Next, the branched rods transform into regular rods and subsequently the regular rods into regular lamellae transitions can be recorded. The regular lamellae exist only within a certain range of growth rates. Finally, the regular rods re-appear at some elevated growth rates.

A new solution to the diffusion equation is provided to describe the micro-field of the solute concentration in the liquid adjacent to the front of the growing eutectic structure. The solution is based on the mass balance in the considered system. Moreover, the existence of the protrusion of the leading eutectic phase over the wetting one is required by the mass balance. The appearance of the d – protrusion in the growing eutectic is well confirmed by the experimental observations of the frozen solid/liquid interface. The mentioned solution satisfies the concept of the eutectic coupled growth according to which undercooling of the leading phase is less than undercooling of the wetting eutectic phase. Also, the Ti – solute micro-segregation / redistribution is analyzed within the matrix of the single crystal. The micro-segregation is described as a result of the solution to the adequate, newly developed differential equation. The definition for the solute redistribution is given by the subsequently / separately formulated relationship. This definition takes into account both extent -, and intensity of the solute redistribution.

Finally, the entropy production is calculated for the regular lamellae -, and for the regular rods formation, respectively. The entropy production is a function of some parameters which define the eutectic phase diagram, coefficient of the diffusion in the liquid, and some capillary parameters connected with the mechanical equilibrium located at the triple point of the solid/liquid interface. Branches formation is related to the marginal stability. A new criterion is formulated and subjected to successful verification. It is: in the structural – thermodynamic competition the winner is this kind of the pattern for which minimum entropy production has a lower value.

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Authors and Affiliations

W. Wołczyński
ORCID: ORCID
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Abstract

Stone mastic asphalt is a gap-graded mix and is usually related to its high bitumen content and its skeleton-like constitution. Although famous for its durability, high resistance to fatigue and rutting, issues such as bleeding and premature aging do occur in the mix since it has a high bitumen content and voids due to its gap-graded structure. In order to encounter these problems from affecting the mix, some instances such as adding additives, rejuvenators and stabilizers into the mixture has been implemented. Nowadays, nano materials are being used in the asphalt mixtures and nano titanium is being introduced as a modifier to the asphalt binder in order to improve the mechanical properties of the stone mastic asphalt mix. The related tests done in order to access the improvement are resilient modulus, dynamic creep, moisture susceptibility and binder drain down. The content of nano titanium used in this research are 1%, 2%, 3%, 4% and 5%. This study is done to assess the mechanical performance of stone mastic asphalt with nano titanium modified binder.
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Authors and Affiliations

Nur Syafiqah Shamimi Mohd Zali
1
ORCID: ORCID
Khairil Azman Masri
1
ORCID: ORCID
Ramadhansyah Putra Jaya
1
ORCID: ORCID
Mohd Mustafa Al Bakri Abdullah
2
ORCID: ORCID
Muzamir Hasan
1
ORCID: ORCID
Mohd Rosli Mohd Hasan
3
ORCID: ORCID
Bartłomiej Jeż
4
ORCID: ORCID
Marcin Nabiałek
4
ORCID: ORCID
Marek Sroka
5
ORCID: ORCID
Paweł Pietrusiewicz
4
ORCID: ORCID

  1. Department of Civil Engineering, College of Engineering, Universiti Malaysia Pahang, 26300 Gambang, Kuantan, Pahang, Malaysia
  2. Faculty of Chemical Engineering Technology, Universiti Malaysia Perlis, 02600 Arau, Perlis, Malaysia
  3. School of Civil Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia
  4. Department of Physics, Faculty of Production Engineering and Materials Technology, Czestochowa University of Technology, 42-201 Czestochowa, Poland
  5. Division of Materials Processing Technology and Computer Techniques in Materials Science, Silesian 21 University of Technology, Poland

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