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Abstract

This paper presents the problem of the increasing negative impact of urban heat islands (UHI) on urban residents based on land surface temperature (LST). It is assumed that water bodies in the agglomeration remain cooler than the air and surrounding urban areas. The study aimed to determine the impact of water bodies and surrounding areas covered by trees on the temperature of an urban area and to minimise the impact of UHI on the life quality of people in the temperate climate zone at day temperatures 25°C (W day) and 29°C (H day). In the adopted research methodology, 167 reservoirs, larger than 1 ha, located within 300 m of urban areas, were analysed. Satellite thermal imagery, spatial land use data (Corine Land Cover), and local land characteristics were used. The average temperature of the reservoirs was appropriately at 4.69°C on W day and 1.9°C for H day lower than in residential areas. The average temperature of areas at a distance of 30 m from the reservoirs was 2.69°C higher onWand 0.32°C higher on H than the water of the reservoirs. The area covered by trees was 0.52°C lower on W day and 0.39°C lower on H day than the residential areas located at a distance of 300 m from the reservoir. On terrestrial areas, the lowest temperature was observed in the area covered by trees within 0–30 m from reservoirs both on warm and hot days. Based on the results of this study, UHI mitigation solutions can be suggested.
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Authors and Affiliations

Edyta Sierka
1
ORCID: ORCID
Łukasz Pierzchała
2

  1. University of Silesia in Katowice, Faculty of Natural Sciences, Jagiellońska St. 28, 40-032 Katowice, Poland
  2. Central Mining Institute in Katowice, Katowice, Poland
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Abstract

Recently, aluminum matrix syntactic foams (AMSFs) have become notably attractive for many different industrial areas like automotive, aerospace, construction and defense. Owing to their low density, good compression response and perfect energy absorption capacity, these advanced composite materials are also considered as strong alternatives to traditional particle reinforced composites and metal foams. This paper presents a promising probability of AMSF fabrication by means of industrial cold chamber die casting method. In this investigation, contrary to other literature studies restricted in laboratory scale, fully equipped custom-build cold chamber die casting machine was used first time and all fabrication steps were designed just as carried out in the real industrial high pressure casting applications. Main casting parameters (casting temperature, injection pressure, piston speed, filler pre-temperature and piston waiting time) were optimized in order to obtain flawless AMSF samples. The density alterations of the syntactic foams were analyzed depending upon increasing process values of injection pressure, piston speed and piston waiting time. In addition, macroscopic and microscopic investigations were performed to comprehend physical properties of fabricated foams. All these efforts showed almost perfect infiltration between filler particles at the optimized injection parameters.

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Authors and Affiliations

C. Bolat
A. Goksenli
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Abstract

The article presents the most important causes of the unstable connection between cast iron ring inserts and the silumin casting of an engine piston. It is shown that manufacturing defects are mainly related to the alfin processing of inserts in Al-Si alloy (the so-called AS9 alloy). Exceeding the permissible iron content in AS9 alloy causes the crystallization of brittle -Al5FeSi phases. Their unfavorable morphology and large size are the main reasons for the weakening of the diffusion connection between the inserts and the piston, causing an unacceptable proportion of defective products. The study presented in this work was conducted under industrial conditions on a population of 10.000 pistons. Quality control data, production parameters, as well as the micro- and macro-structures of the cast iron inserts, and the interface area between the inserts and the silumin piston, were analyzed. Material and technological solutions have been proposed to reduce the occurrence of casting defects at the insert-piston joint. This includes the introduction of so-called "morphological correctors" of the -Al5FeSi phases, reducing the possibility of gaseous impurities in the AS9 alloy and optimizing the temperature of the alfin alloy.
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Authors and Affiliations

M. Szucki
1
ORCID: ORCID
J. Piątkowski
2
ORCID: ORCID
M. Czerepak
3

  1. Foundry Institute, Technische Universität Bergakademie Freiberg, Bernhard-von-Cotta-Str. 4,09599 Freiberg, Germany
  2. Department of Material Technologies, Silesian University of Technology, Krasińskiego 8, 40-019 Katowice, Poland
  3. Federal-Mogul Gorzyce sp. z o.o., Odlewników 52, 39-432 Gorzyce, Poland

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