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Number of results: 20
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Abstract

The article presents research results of the strength parameters of HPC achieved in various research conditions. The research was carried out on substantially different samples, both as to the size as the slenderness ratio. Moreover, the assessment of the effect of speed of a load on strength parameters as well as other factors which in a significant way show the difference in the strength values was made. For comparison, the results were also applied to the relations known in ordinary concrete.

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Authors and Affiliations

Daniel Wałach
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Abstract

This paper addresses the tensile and flexural strength of HPC (high performance concrete). The aim of the paper is to analyse the efficiency of models proposed in different codes. In particular, three design procedures from: the ACI 318 [1], Eurocode 2 [2] and the Model Code 2010 [3] are considered. The associations between design tensile strength of concrete obtained from these three codes and compressive strength are compared with experimental results of tensile strength and flexural strength by statistical tools. Experimental results of tensile strength were obtained in the splitting test. Based on this comparison, conclusions are drawn according to the fit between the design methods and the test data. The comparison shows that tensile strength and flexural strength of HPC depend on more influential factors and not only compressive strength.

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Authors and Affiliations

M. Kępniak
P. Woyciechowski
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Abstract

The new control method for Permanent Magnet Synchronous Motor (PMSM) and Brushless DC Motor (BLDCM) is presented. Balance of power in three-phase permanent magnet synchronous motor is based on conservation of energy law. Space vector theory determined by instantaneous value of phase quantities is applied in mathematical analysis. It makes possible to estimate instantaneous values of reactive energy and electromagnetic torque. The presented control method belongs to flux-oriented method; it synchronizes current vector in relation to stator flux vector. New structure of control system as well as block diagram containing all basic elements and operating modes of specific blocks are described. Simulation studies and experimental results for two kinds of motors: PMSM and BLDCM were performed based on the dSPACE development DS1103 system.

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Authors and Affiliations

M. Janaszek
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Abstract

This paper presents the results of research on high performance concretes (HPC) modified by theaddition of polypropylene fibres
(PP fibres). The scope of the research was the measurement of theresidual transport properties of heated and recooled concretes: gas permeability and surface waterabsorption. Seven types of concrete modified with fibrillated PP fibres were tested. Three lengths: 6,12 and 19 mm and three amounts of fibres: 0, 0.9 and 1.8 kg/m3 were used. The research programmewas designed to determine which length of fibres, used in which minimum amount, will, after thefibres melt, permit the development of a connected network and pathway for gases and liquids.

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Authors and Affiliations

I. Hager
T. Tracz
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Abstract

The paper presents the results of experimental investigations performed by the authors on the casting position factor. It was proved that at the height of reinforced concrete elements there are different bond conditions. Moreover, the bond depends on concrete mechanical properties, element height as well as concrete mix composition and consistency. The experiments also showed the advisability of determining the casting position factor separately for bars from normal concrete and those from high–performance concrete (HPC). The analysis of investigation results has shown that “good” bond conditions are a relative concept and depend on, among other things, element height. The higher the element the better the concrete to lower bars bond. Consequently, elements of considerable height (higher than 600 mm) demonstrate a bigger difference between concrete to upper bars bond and concrete to lower bars bond.

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Authors and Affiliations

Piotr Dybeł
Kazimierz Furtak
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Abstract

The present study aimed to investigate the contamination of poultry feed with aflatoxin B1 and zearalenone at laying hen farms in Tehran suburbs. The poultry feed was selected from five laying hen farms. A total of 60 poultry feed samples were collected from each farm during four consecutive seasons, from spring to winter of 2021. High-performance liquid chromatography was used to determine the amount of aflatoxin B1 and zearalenone. The mean aflatoxin B1 and zearalenone concentrations in various seasons showed significant differences (p<0.01). The highest reported aflatoxin concentration was in winter, with a mean concentration of 1366.53±77.85 ng/kg. The lowest concentrations were reported in autumn and summer, indicating a significant difference (p<0.01). The highest concentration of zearalenone was reported in summer, with a mean concentration of 150.72±10.35 μg/kg. The lowest concentration was reported in winter, with a mean concentration of 22.87±10.35 μg/kg, indicating a statistically significant difference (p<0.01). Overall, the concentrations of aflatoxin B1 and zearalenone toxins significantly differed in various poultry farms. The poultry farm D had the highest aflatoxin contamination with a mean concentration of 648.08±59.89 ng/kg. Poultry farms A, B, and C had the highest zearalenone concentrations with mean concentrations of 125.17±20.61, 96.04±20.61, and 99.49±20.61 μg/kg, respectively. Autumn was the only season showing significant differences regarding zearalenone toxin concentration in poultry farms.
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Authors and Affiliations

A. Sohrabi
1
M.H. Movassaghghazani
2
J. Shayegh
3
A.R. Karamibonari
3
F. Tajedini
4

  1. Faculty of Veterinary Medicine, Shabestar Branch, Islamic Azad University, Shabestar, Iran
  2. Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Shabestar Branch, Islamic Azad University, Shabestar, Iran
  3. Department of Pathobiology, Faculty of Veterinary Medicine, Shabestar Branch, Islamic Azad University, Shabestar, Iran
  4. Department of Basic Sciences, Faculty of Veterinary Medicine, Karaj Branch, Islamic Azad University, Karaj, Iran
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Abstract

This paper presents an innovative solution in the form of a virtual reality (VR) and high performance computing (HPC) system dedicated to aid designing rotary forming processes with laser beam reheating the material formed. The invented method allowing a virtual machine copy to be coupled with its actual counterpart and a computing engine utilizing GPU processors of graphic NVidia cards to accelerate computing are discussed. The completed experiments and simulations of the 316L stainless steel semi-product spinning process showed that the developed VR-HPC system solution allows the manufacturing process to be effectively engineered and controlled in industrial conditions.
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Authors and Affiliations

Marcin Hojny
Przemysław Marynowski
ORCID: ORCID
G. Lipski
1
ORCID: ORCID
T. Gądek
2
ORCID: ORCID
Ł. Nowacki
2
ORCID: ORCID

  1. AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Kraków, Poland
  2. Research Network Łukasiewicz – Metal Forming Institute, Jana Pawła II 14, 61-139 Poznań, Poland
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Abstract

This study investigates (1) the effect of quality information on quality performance through process control and (2) the moderating role of shop floor leadership on the relationship between quality information and quality performance in the context of manufacturing plants on a global basis. The moderated mediation analysis with a bootstrapping approach was employed to analyse data for hypotheses testing. The data is from the fourth-round dataset of the High- Performance Manufacturing Project, collected from manufacturing plants worldwide. The results indicate that (1) quality information is positively associated with quality performance through process control, and (2) shop floor leadership (i.e., supervisory interaction facilitation) positively moderates the indirect effect of quality information on quality performance; that is, the shop floor leadership practice strengthens the effect of quality information on quality performance through process control. This study also has a practical implication for top managers who should consider the vital role of leadership practices adopted by shop floor supervisors in implementing total quality management practices and should raise awareness that leadership practices are not only for the ‘C-suite’ but also for shop floor supervisors.
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Authors and Affiliations

Ngoc Anh Nguyen
Chi Phan Anh
Thi Xuan Thoa Pham
Matsui Yoshiki
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Abstract

This paper presents the results of investigation on polycyclic aromatic hydrocarbons (PAHs) concentration in sludge coming from industrial wastewater treatment. The sludge was characterised according to chemical composition and heavy metal contents. Leaching of PAHs from sludge in dynamic conditions was also done with lizymetric columns used to simulate the real conditions during the storage of wastes. The changes or PAHs concentration in sludge stored under various lights conditions were also compared (daylight and darkness). A periodic extraction method with cyclohexane was used to select PAHs from samples. High performance liquid chromatography (HPLC) with fluorescent detector was used to analyse PAHs. Six PAHs listed by WHO were analysed (fluoranthene Fl, benzo(b)fluoranthene BbF, benzo(k)fluoranthene BkF, benzo(a)pyrene BaP, benzo(ghi)perylene BghiP and indeno(l ,2,3-cd)pyrene IP).
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Authors and Affiliations

Agnieszka Popenda
Maria Włodarczyk-Makuła
Marta Janosz-Rajczyk
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Abstract

Tetranychus urticae (Acari: Tetranychidae) infesting many plants but Mentha viridis L., and Mentha piperita L., were low in number of infestation. Therefore the objective of this study was to identify the resistance of M. viridis and M. piperita plants against T. urticae by studying the external shape and internal contents of those plants. For morphological studies, dried leaves were covered with gold utilizing an Edwards Scan coat six sputter-coater. For histological studies, arrangements of Soft Tissue technique were used. For phytochemical studies, the plants were cut, dried and then high performance liquid chromatography (HPLC) was used. While feeding the mites were collected from the area between oily glands, trichomes and respiratory stomata in both mint species. The most important leaf structures in aromatic plants are the oily glands found on the external part of the leaves (both upper and lower epidermis). The number of oil glands in M. viridis leaves was greater than in M. piperita; the trichomes on the epidermis of M. viridis were greater in number than in M. piperita; the spongy mesophyll in M. viridis was much thicker than in M. piperita. The essential oils in the leaves of both mint species contained 71 compounds representing 99.61% of the total oil constituents identified from M. viridis before infestation, and 90.95% after infestation, and about 99.65% from M. piperita before infestation, and 99.98% after infestation.

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Authors and Affiliations

Sally Farouk Allam
Basem Abdel-Nasser Soudy
Ahmed Salah Hassan
Mahmoud Mohamed Ramadan
Doha Abo Baker
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Abstract

The use of elastic bodies within a multibody simulation became more and more important within the last years. To include the elastic bodies, described as a finite element model in multibody simulations, the dimension of the system of ordinary differential equations must be reduced by projection. For this purpose, in this work, the modal reduction method, a component mode synthesis based method and a moment-matching method are used. Due to the always increasing size of the non-reduced systems, the calculation of the projection matrix leads to a large demand of computational resources and cannot be done on usual serial computers with available memory. In this paper, the model reduction software Morembs++ is presented using a parallelization concept based on the message passing interface to satisfy the need of memory and reduce the runtime of the model reduction process. Additionally, the behaviour of the Block-Krylov-Schur eigensolver, implemented in the Anasazi package of the Trilinos project, is analysed with regard to the choice of the size of the Krylov base, the blocksize and the number of blocks. Besides, an iterative solver is considered within the CMS-based method.

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Authors and Affiliations

Thomas Volzer
Peter Eberhard
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Abstract

This work outlines a unified multi-threaded, multi-scale High Performance Computing (HPC) approach for the direct numerical simulation of Fluid-Solid Interaction (FSI) problems. The simulation algorithm relies on the extended Smoothed Particle Hydrodynamics (XSPH) method, which approaches the fluid flow in a Lagrangian framework consistent with the Lagrangian tracking of the solid phase. A general 3D rigid body dynamics and an Absolute Nodal Coordinate Formulation (ANCF) are implemented to model rigid and flexible multibody dynamics. The twoway coupling of the fluid and solid phases is supported through use of Boundary Condition Enforcing (BCE) markers that capture the fluid-solid coupling forces by enforcing a no-slip boundary condition. The solid-solid short range interaction, which has a crucial impact on the small-scale behavior of fluid-solid mixtures, is resolved via a lubrication force model. The collective system states are integrated in time using an explicit, multi-rate scheme. To alleviate the heavy computational load, the overall algorithm leverages parallel computing on Graphics Processing Unit (GPU) cards. Performance and scaling analysis are provided for simulations scenarios involving one or multiple phases with up to tens of thousands of solid objects. The software implementation of the approach, called Chrono::Fluid, is part of the Chrono project and available as an open-source software.

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Authors and Affiliations

Arman Pazouki
Radu Serban
Dan Negrut
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Abstract

This paper presents the details of optimized mix design for normal strength and high performance concrete using particle packing method. A critical review of mix design methods have been carried out for normal strength concrete using American Concrete Institute (ACI) and Bureau of Indian Standards (BIS) methods highlighting the similarities and differences towards attaining a particular design compressive strength. Mix design for M30 and M40 grades of concrete have been carried out using ACI, BIS and particle packing methods. Optimization of concrete mix has been carried out by means of particle packing method using EMMA software, which employs modified Anderson curve to adjust the main proportions. Compressive strength is evaluated for the adjusted proportions and it is observed that the mixes designed by particle packing method estimates compressive strength closer to design compressive strength. Further, particle packing method has been employed to optimize the ingredients of high performance concrete and experiments have been carried out to check the design adequacy of the desired concrete compressive strength.

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Authors and Affiliations

S. Gopinath
A. Ramachandra Murthy
D. Ramya
Nagesh R. Iyer
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Abstract

The ductility of High Performance Concrete (HPC) can develop both in tension and compression.This aspect is evidenced in the present paper by measuring the mechanical response of normalvibrated concrete (NC), self-compacting concrete (SC) and some HPCs cylindrical specimensunder uniaxial and triaxial compression. The post-peak behaviour of these specimens is definedby a non-dimensional function that relates the inelastic displacement and the relative stress duringsoftening. Both for NC and SC, the increase of the fracture toughness with the confinement stressis observed. Conversely, all the tested HPCs, even in absence of confinement, show practically thesame ductility measured in normal and self-compacting concretes with a confining pressure. Thus,the presence of HPC in compressed columns is itself sufficient to create a sort of active distributedconfinement.

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Authors and Affiliations

A.P. Fantilli
H. Mihashi
P. Vallini
B. Chiaia
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Abstract

In the recent years a tendency for design of increasingly slender structures with the use of high performance concrete has been observed. Moreover, the use of high performance concrete in tunnel structures, subject to high loads with possibility of extreme loads occurrence such as fire, has an increasing significance. Presented studies aimed at improving high performance concrete properties in high temperature conditions (close to fire conditions) by aeration process, and determining high temperature impact on the concretes features related to their durability. In this paper it has been proven that it is possible to obtain high performance concretes resistant to high temperatures, and additionally that modification of the concrete mix with aerating additive does not result in deterioration of concrete properties when subject to water impact in various form.

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Authors and Affiliations

W. Jackiewicz-Rek
T. Drzymała
A. Kuś
M. Tomaszewski
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Abstract

The paper deals with the properties and microstructure of Reactive Powder Concrete (RPC), which was developed at Cracow University of Technology. The influence of three different curing conditions: water (W), steam (S) and autoclave (A) and also steel fibres content on selected properties of RPC was analyzed. The composite characterized by w/s ratio equal to 0.20 and silica fume to cement ratio 20%, depending on curing conditions and fibres content, obtained compressive strength was in the range from 200 to 315 MPa, while modulus of elasticity determined during compression was about 50 GPa. During three-point bending test load-deflection curves were registered. Base on aforementioned measurements following parameters were calculated: flexural strength, stress at limit of proportionality (LOP), stress at modulus of rapture (MOR), work of fracture (WF), and toughness indices I₅, I₁₀ and I₂₀. Both amount of steel fibres and curing conditions influence the deflection of RPC during bending.

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Authors and Affiliations

T. Zdeb
J. Śliwiński
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Abstract

A novel dual mode logic (DML) model has a superior energy-performance compare to CMOS logic. The DML model has unique feature that allows switching between both modes of operation as per the real-time system requirements. The DML functions in two dissimilar modes (static and dynamic) of operation with its specific features, to selectively obtain either low-energy or high-performance. The sub-threshold region DML achieves minimum-energy. However, sub-threshold region consequence in performance is enormous. In this paper, the working of DML model in the moderate inversion region has been explored. The near-threshold region holds much of the energy saving of subthreshold designs, along with improved performance. Furthermore, robustness to supply voltage and sensitivity to the process temperature variations are presented. Monte carol analysis shows that the projected near-threshold region has minimum energy along with the moderate performance.

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Authors and Affiliations

Pavankumar Bikki
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Abstract

In recent years, carbon fibres have been extensively used to strengthen concrete structures. In most cases, the lamination process is carried out using epoxy resin as matrix. In some cases, especially when strengthen structural elements made of weak concrete, it is possible to replace the epoxy resin with an inorganic, cement matrix, while at the same time maintaining a sufficient efficiency of strengthen understood as the percentage increase in the compressive strength of concrete samples due to the applied reinforcement in relation to the reference concrete. In these studies, elements of carbon fibres mats that are reinforced with a cement matrix were used as the starting product for fibre recovery. The laminate, which was used to reinforce concrete elements, was detached from the concrete surface and subjected to processing in order to obtain clean carbon fibre scraps without cement matrix. Then, the obtained carbon material, in shaped form, was used to strengthen self-compacting, high performance, fibre reinforced concrete (SCHPFRC). For comparative purposes, this concrete was also strengthened by carbon fibre mats (with one and three layers of CFRP). Each samples were tested in uniaxial compression test. The compressive strength of concrete reinforced with 1 and 3 layers of CFRP was higher by 37.9 and 96.3%, respectively, compared to the reference concrete. On the other hand, the compressive strength of concrete reinforced with 1 and 3 layers of carbon fibre scrapswas higher by 11.8 and 40.1%, respectively. Regardless of the reinforcement technique used, the composite elements showed a higher deformability limit in comparison plain concrete. The obtained results showed that it is possible to reuse carbon fibre to strengthen structural elements made of SCHPFRC effectively, using simple processing methods.
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Authors and Affiliations

Krzysztof Ostrowski
1
ORCID: ORCID
Kazimierz Furtak
1
ORCID: ORCID

  1. Cracow University of Technology, Faculty of Civil Engineering, Warszawska 24, 31-155 Cracow, Poland
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Abstract

Continuous steel-concrete composite girder can fully utilize material strength and possess large spanning ability for bridge constructions. However, the weak cracking resistance at the negative bending moment region of the girder seriously harms its durability and serviceability. This paper investigates practical techniques to improve the cracking performance of continuous steel-concrete composite girders subjected to hogging moment.Areal continuous girderwas selected as the background bridge and introduced for numerical analysis. Modeling results show that under the serviceability limit state, the principle stress of concrete slabs near the middle piers of the bridgewas far beyond the allowable material strength, producing a maximum tensile stress of 10.0 MPa. Approaches for strengthening concrete decks at the negative moment region were developed and the effectiveness of each approach was assessed by examing the tensile stress in the slabs. Results indicate that the temporary counterweight approach decreased the maximum tensile stress in concrete slabs by 22%. Due to concrete shrinkage and creep, more than 65% of the prestressed compressive stresses in concrete slabs were finally dispersed to the steel beams. A thin ultra-high performance concrete (UHPC) overlay at the hogging moment region effectively increased the cracking resistance of the slabs, and practical engineering results convicted the applicability of the UHPC technique.
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Authors and Affiliations

Min Cai
1
ORCID: ORCID
Wenjie Li
2
ORCID: ORCID
Zhiyong Wan
3
ORCID: ORCID
Jianjun Sheng
1
ORCID: ORCID
Juliang Tan
4
ORCID: ORCID
Chao Ma
1
ORCID: ORCID

  1. Guangdong Highway Construction Co., LTD, 510623 Guangzhou, China
  2. Guangdong Yunmao Expressway Co. Ltd, 525346 Guangzhou, China
  3. Guangdong Communication Planning & Design Institute Co., Ltd,510507 Guangzhou, China
  4. Guangdong Communication Planning & Design Institute Co., Ltd, 510507 Guangzhou, China
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Abstract

This study provides a comparative analysis of natural nanosilica (NSn), which is an extract of natural silica sand processed into nanosilica with commercial nanosilica (NSc) derived from semiconductor industrial waste, in 80 MPa high performance concrete (HPC). The percentage of using nanosilica is (3%, 5%, 10%, 15%) by weight of cement used directly and combined with 5% silica fume. Analysis was carried out through compressive strength test, durability through permeability test, rapid chloride penetration test (RCPT), and microstructure test through scanning electron microscopy (SEM). The results of the analysis show that natural nanosilica is equivalent to commercial nanosilica, in applications it is better to use silica fume incorporation. The optimum percentage of using NSn10% and (SF) 5%, while 5% NSc and 5% SF, in these proportions shows the best compressive strength and durability. It’s just that the use of natural nanosilika is 5% more than commercial nanosilika. The benefit of this research is that natural materials such as silica sand with high SiO2 content, can be processed into nanosilica as an advanced material, which can be used as an eco-friendly construction material.
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Authors and Affiliations

A.R. Indra Tjahjani
1
ORCID: ORCID
Mohamad Ali Fulazzaky
2
ORCID: ORCID
Jonbi Jonbi
1
ORCID: ORCID
Nuryani Tinumbia
1
ORCID: ORCID
Wita Meutia
1
ORCID: ORCID
Daral Suraedi
1
ORCID: ORCID
Prima Ranna
1
ORCID: ORCID

  1. Pancasila Univesity, Faculty of Civil Engineering, Jagakarsa, South Jakarta, 12630, Indonesia
  2. Ton Duc Thang University, Sustainable Development in Civil Engineering Research Group (SDCE), 19 Nguyên Huu Tho, Tân Hung, Quân 7, Hô Chí Minh 700000, Vietnam

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