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Volume 115 (2018): Edition 11 (November 2018)

Volume 115 (2018): Edition 10 (October 2018)

Volume 115 (2018): Edition 9 (September 2018)

Volume 115 (2018): Edition 8 (August 2018)

Volume 115 (2018): Edition 7 (July 2018)

Volume 115 (2018): Edition 6 (June 2018)

Volume 115 (2018): Edition 5 (May 2018)

Volume 115 (2018): Edition 4 (April 2018)

Volume 115 (2018): Edition 3 (March 2018)

Volume 115 (2018): Edition 2 (February 2018)

Volume 115 (2018): Edition 1 (January 2018)

Volume 114 (2017): Edition 11 (November 2017)

Volume 114 (2017): Edition 10 (October 2017)

Volume 114 (2017): Edition 9 (September 2017)

Volume 114 (2017): Edition 8 (August 2017)

Volume 114 (2017): Edition 7 (July 2017)

Volume 114 (2017): Edition 6 (June 2017)

Volume 114 (2017): Edition 5 (May 2017)

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Volume 114 (2017): Edition 3 (March 2017)

Volume 114 (2017): Edition 2 (February 2017)

Volume 114 (2017): Edition 1 (January 2017)

Détails du magazine
Format
Magazine
eISSN
2353-737X
Première publication
20 May 2020
Période de publication
1 fois par an
Langues
Anglais

Chercher

Volume 115 (2018): Edition 7 (July 2018)

Détails du magazine
Format
Magazine
eISSN
2353-737X
Première publication
20 May 2020
Période de publication
1 fois par an
Langues
Anglais

Chercher

15 Articles
Accès libre

Is the Energy Price Premium Spatially Aggregated? A Listing Price Analysis of the Residential Market in Barcelona

Publié en ligne: 21 May 2020
Pages: 5 - 19

Résumé

Abstract

Building energy efficiency has aroused much discussion around the world. Energy Performance Certificates (EPCs) and relevant regulations and legislation have been established and enforced in the past 15 years due to the extreme 40% consumption of total energy and 38% of total CO2 emissions caused by residential buildings in Europe. This paper aims to confirm the energy premium in the Metropolitan Area of Barcelona (AMB) and the presence of spatial homogeneity of this energy premium with OLS hedonic prices and the GWR model. The results suggest that the energy premium causes a 12.2% housing price increase from Class G to Class A, or an implicit housing price rise of 1.9% with every ranking of EPC ordinal scale improvement. Furthermore, the areas with a higher incidence of energy labelling are situated in the middle and north-eastern parts of AMB that are inhabited by skilled professionals who more commonly have a higher university education.

Mots clés

  • Energy Performance Certificates (EPCs)
  • housing price
  • spatial aggregation
Accès libre

Gorlice Cemetery- a Funeral Space in the Landscape

Publié en ligne: 21 May 2020
Pages: 21 - 34

Résumé

Abstract

In Poland nowadays new cemeteries are hardly ever designed. It usually comes down to designating an area and equipping with the necessary road system and fence. The design of burial fields, transport facilities, landscaping, and architectural cemetery facilities are not considered a necessity. When the city of Gorlice launched a cemetery project it announced an architectural competition, which was won by eM4 Pracownia Architektury Brataniec. Currently, the cemetery project has been submitted and is waiting for a building permit. This article presents the idea, concept, and design process of the cemetery – a contemporary sacred space that blends into the surrounding landscape.

Mots clés

  • cemetery space
  • funeral home
  • cemetery greenery
  • cemetery alley
  • plant symbolism
Accès libre

Visual Transformations within the Space of the City. The Bilbao Effect

Publié en ligne: 21 May 2020
Pages: 35 - 49

Résumé

Abstract

The article focuses on the changes to the face of the space of the city that have been initiated towards the end of the twentieth and which have been developing since the start of the twenty-first century in Bilbao, resulting from a broadly understood process of urban regeneration. It refers to the main problems associated with this process, which cover the spatial, economic and social sides of the city. It discusses the use of art in the humanisation of a place, improving its attractiveness and promoting modern solutions in architecture and urban planning. The process of holistic, systemic urban planning-related transformations of a decayed area has covered improving the accessibility of the site and the placement of a structure that crystallised the spatial layout. The success of this programme can constitute an indication for other centres affected by the necessity to introduce functional and spatial changes, as well as an effective municipal policy.

Mots clés

  • Bilbao
  • urban regeneration
  • transformations
  • space
  • accessibility
  • art
Accès libre

Zakopane – in Defence of Cultural Landscape – Clerks’ Parcels

Publié en ligne: 21 May 2020
Pages: 51 - 59

Résumé

Abstract

This article addresses the issue of cultural values regarding the need to protect one of the housing estates in Zakopane – known as the Clerks’ Parcels. From the north-west the area is enclosed by Sabały St., from the west by Piłsudskiego St., from the south by Czecha St., and on the east side it borders on the Faluszowy Brook. It was designed and shaped during the 1920s according to the project of the renowned architect, Karol Stryjeński. The Clerks’ Parcels area is not merely a defined, consciously shaped urban layout, but also culturally significant objects listed in the heritage register and entered in the district monument records. In the opinion of the authors of this article, the area deserves to be under a statutory form of protection, namely listed in the immovable monument register of the Lesser Poland Voivodeship, which would safeguard that space against degradation and cultural annihilation.

Mots clés

  • Zakopane
  • Clerks’ Parcels
  • urban layout of Zakopane
Accès libre

The Influence of the Development of Private Air Communication on the Architecture and Urban Planning of the 21st Century

Publié en ligne: 21 May 2020
Pages: 61 - 73

Résumé

Abstract

In the first part, the article describes the stages of the development of gyroplanes and the influence of wartime policy on the interest in light aircraft. Also presented are links and the possibilities of using gyroplanes in various sectors of the economy. The authors, based on source texts, present the current position of the aviation industry in the Polish economy and attempt to diagnose its development capabilities. As a result, factors responsible for the current condition of the light aviation industry and its links with architecture and urban planning are submitted. The question is posed: what consequences will the development of the aviation industry bring for architecture and urban planning, for the community and the image of 21st century cities?

Mots clés

  • metropolitan transport
  • urban planning
  • urban mobility
  • urban airspace
  • landing areas
  • helipads
  • high-rise buildings
  • ultra-light aviation
  • helicopters
  • gyroplanes
  • architecture
  • future of aviation
  • personal aviation
  • air traffic control
Accès libre

Comparative Analysis of the Coarse Aggregate Shapes used to Manufacturing High Performance Self-Compacting Concrete

Publié en ligne: 21 May 2020
Pages: 75 - 86

Résumé

Abstract

The influence of the shape of coarse aggregate on the properties of fresh concrete mixes, and the strength of high-performance self-compacting concrete (HPSCC) is important issue. In this study, irregular and regular grains were separated from the basalt, porphyry and granite coarse aggregate. The shape of these grains was determining using digital image analysis and was in accordance with the European Standard [19]. The aspect ratio (AR) and roundness (R) were ascertained in order to highlight the differences in the coarse aggregate shape used the design HPSCC. The study indicates that using the same crushing system, varied parameters of the shape of coarse aggregates were obtained. It was determined that the best fitting distribution for aspect ratio and roundness at a 95% confidence level is the generalised extreme value distribution.

Mots clés

  • coarse aggregate
  • shape
  • computer image analysis
  • self-compacting concrete
Accès libre

Control of the Vibration Structure Induced during Works with the use of Explosives

Publié en ligne: 21 May 2020
Pages: 87 - 99

Résumé

Abstract

This article presents the results of research on controlling the structure of vibrations induced during the firing of explosives with the use of non-electrical and electronic systems and the influence of the vibration structure during a transition from the ground to the building. The use of procedures associated with the selection of millisecond delay for firing explosive charges during blasting allows to get the excitation of favourable structure vibrations, thanks to a strong damping which is obtained at the transition from the ground to the structure. This means that optimally designed blasting works do not have to limit the mass of the explosives in the borehole as well as their number.

Mots clés

  • Open-pit mining
  • blasting technique
  • millisecond blasting
  • vibration structure
  • impact of vibrations on buildings
Accès libre

Transport Attractiveness of Shopping Malls

Publié en ligne: 21 May 2020
Pages: 101 - 112

Résumé

Abstract

The dynamic development of analytical methods used for the modelling of town travel increases the demand for various kinds of data necessary to estimate the road traffic volume on transport networks. The estimation of traffic volume generated by particular facilities located in a city is an important element of modelling. Among these facilities, large shopping malls are considered to be one of the most significant road traffic generators. The estimation of transport attractiveness of such large objects is a big challenge in modelling customers’ journey to large shopping malls. In this study, a new method is proposed for the assessment of transport attractiveness of large trade and service facilities.

Mots clés

  • shopping malls
  • attractiveness
  • road traffic modelling
Accès libre

The Evaluation of Control Quality in Automatic Systems Based on Maximum Error

Publié en ligne: 21 May 2020
Pages: 113 - 120

Résumé

Abstract

The article presents an approach that uses the value of the maximum error to assess the quality of control in automatic control systems. The integral-square-error criterion is analysed together with the signals that enable its derivation. Signals with two constraints are considered.

Mots clés

  • Control error
  • integral-square criterion
  • maximising signals
  • constraints of signals
Accès libre

The Application of Non-Standard GPR Techniques for the Examination of River Dikes

Publié en ligne: 21 May 2020
Pages: 121 - 138

Résumé

Abstract

A standard measurement procedure currently applied in the ground penetrating radar (GPR) method is short-offset reflection profiling. As this procedure delivers data that is suited only for qualitative interpretation, its application should be limited exclusively to reconnaissance surveys. There are various other techniques used in GPR surveying that may be regarded as non-standard, such as multi-offset and adaptable-polarisation surveying and tomography. Because these techniques deliver information that allows for quantitative interpretation, they could be applied for the detailed examination of geological media and investigations of various buried anthropogenic targets. This paper focuses on the application of non-standard GPR techniques for the detection of high-porosity zones in river dikes. REsults from both field surveys and numerical modelling are presented.

Mots clés

  • GPR
  • ground penetrating radar
  • non-standard surveys
  • river dike
Accès libre

A Prototype of a Small Stirling Refrigeration Unit

Publié en ligne: 21 May 2020
Pages: 139 - 151

Résumé

Abstract

This paper presents original mathematical models which can be used for the size optimization of particular elements in the design process of cooling appliances using the Stirling cycle. The models were used to design a prototype of the Stirling cooling device. The project employs a unique piston–cylinder kinematic pair which enables dry fiction work. Original platelet and ball ceramic regenerators were designed. The presented model assumes adiabatic transformations of the medium in the cylinders as this approach yields more realistic results in comparison to a simple isothermal Schmidt analysis. One cycle of the device (one rotation of the shaft) is divided into elementary angles Φ, where the state of the gas is considered as constant. As a result, states of the gas in individual components of the working space are determined in any given, discrete time steps of the Stirling cycle.

Mots clés

  • Stirling cycle
  • Stirling engine
  • Stirling cooler
  • Stirling cycle numerical modelling
  • optimisation of Stirling engine
  • cogeneration
  • heat transfer
Accès libre

A Note On Browkin’s and Cao’s Cancellation Algorithm

Publié en ligne: 21 May 2020
Pages: 153 - 165

Résumé

Abstract

In this paper, we follow our generalisation of the cancellation algorithm described in our previous paper [A. Tomski, M. Zakarczemny, On some cancellation algorithms, NNTDM. 23, 2017, p. 101–114]. for f being a natural-valued function defined on ℕs s, ≥1 we remove the divisors of all possible values of f in the points in which the sum of coordinates is less than or equal to n. The least non-cancelled number is called the discriminator Df(n). We find formulas, or at least an estimation for this discriminator, in the case of a broad class of sequences.

Mots clés

  • discriminator
  • sequence
  • congruence
  • odious numbers
  • Thue-Morse sequence
Accès libre

Two-Dimensional Numerical Simulation of a Thermoelectric Cooler Module

Publié en ligne: 21 May 2020
Pages: 167 - 178

Résumé

Abstract

The paper presents the methodology and results of a numerical simulation of coupled thermal and electrical phenomena in a thermoelectric (TE) cooler module obtained with the MOOSE Framework released by Idaho National Laboratory. The coupled system of partial differential equations is solved for the value of electric potential and temperature fields. Equations include contributions from electric conduction, Seebeck effect, thermal conduction, Joule heating as well as Peltier and Thomson effects. The values of the cooling capacity and the voltage drop of the module are calculated and compared with the data provided by the manufacturer of the thermoelectric cooler in order to determine if the simplified assumptions adopted in the numerical model are appropriate to reliably infer about the performance of the TE module composed of over one hundred thermoelectric pairs.

Mots clés

  • thermoelectrics
  • Peltier effect
  • Thomson effect
  • Seebeck effect
  • numerical simulation
  • MOOSE
Accès libre

Numerical Simulation of Temperature Distribution during the First Stage of the Friction Stir Alloying Process

Publié en ligne: 21 May 2020
Pages: 179 - 190

Résumé

Abstract

This work demonstrates the numerical modelling of thermal dispersion accompanying the first stage of the friction stir alloying process. It is very important to recognise the temperature field in the modified workpiece in order to identify the zones where the physical material properties are changing. The temperature gradient leads to a drop of yield strength of the material and, as a consequence, the occurrence of the possibility of plastic flow around the tool. An attempt has been made to analyse the axisymmetric thermal problem described by a Fourier equation with an internal heat source in which the heat is derived only from work of frictional forces occurring between the workpiece and the tool material. The example under consideration focuses on the production of an Al-TiC composite using FSA technology. Macrostructure images of the composite and the simulation results confirm the correctness of the applied mathematical model, where the obtained temperature field corresponds with specific FSA zones.

Mots clés

  • FSA
  • temperature field
  • Al-TiC composite
Accès libre

The Microstructure and Properties of Titanium Carbide Reinforced Stainless Steel Matrix Composites Prepared by Powder Metallurgy

Publié en ligne: 21 May 2020
Pages: 191 - 206

Résumé

Abstract

TiC particle-reinforced AISI 316l stainless-steel matrix composites were prepared using conventional powder metallurgy technology. The effect of TiC content on the microstructure and properties of these composites has been investigated with a particular emphasis upon hardness, wear resistance and corrosion resistance in sea water environments. The results showed that TiC particle reinforcement improved the hardness, wear resistance and corrosion resistance of AISI 316l stainless steel. The higher TiC content in the studied composites resulted in a higher hardness of the wear surface and a lower wear rate. The best corrosion resistance in sea water was achieved for sintered AISI 316l – 5% TiC composite.

Mots clés

  • metal matrix composites
  • TiC particles
  • AISI 316L
  • density
  • hardness
  • wear resistance
  • corrosion resistance
  • microstructure
15 Articles
Accès libre

Is the Energy Price Premium Spatially Aggregated? A Listing Price Analysis of the Residential Market in Barcelona

Publié en ligne: 21 May 2020
Pages: 5 - 19

Résumé

Abstract

Building energy efficiency has aroused much discussion around the world. Energy Performance Certificates (EPCs) and relevant regulations and legislation have been established and enforced in the past 15 years due to the extreme 40% consumption of total energy and 38% of total CO2 emissions caused by residential buildings in Europe. This paper aims to confirm the energy premium in the Metropolitan Area of Barcelona (AMB) and the presence of spatial homogeneity of this energy premium with OLS hedonic prices and the GWR model. The results suggest that the energy premium causes a 12.2% housing price increase from Class G to Class A, or an implicit housing price rise of 1.9% with every ranking of EPC ordinal scale improvement. Furthermore, the areas with a higher incidence of energy labelling are situated in the middle and north-eastern parts of AMB that are inhabited by skilled professionals who more commonly have a higher university education.

Mots clés

  • Energy Performance Certificates (EPCs)
  • housing price
  • spatial aggregation
Accès libre

Gorlice Cemetery- a Funeral Space in the Landscape

Publié en ligne: 21 May 2020
Pages: 21 - 34

Résumé

Abstract

In Poland nowadays new cemeteries are hardly ever designed. It usually comes down to designating an area and equipping with the necessary road system and fence. The design of burial fields, transport facilities, landscaping, and architectural cemetery facilities are not considered a necessity. When the city of Gorlice launched a cemetery project it announced an architectural competition, which was won by eM4 Pracownia Architektury Brataniec. Currently, the cemetery project has been submitted and is waiting for a building permit. This article presents the idea, concept, and design process of the cemetery – a contemporary sacred space that blends into the surrounding landscape.

Mots clés

  • cemetery space
  • funeral home
  • cemetery greenery
  • cemetery alley
  • plant symbolism
Accès libre

Visual Transformations within the Space of the City. The Bilbao Effect

Publié en ligne: 21 May 2020
Pages: 35 - 49

Résumé

Abstract

The article focuses on the changes to the face of the space of the city that have been initiated towards the end of the twentieth and which have been developing since the start of the twenty-first century in Bilbao, resulting from a broadly understood process of urban regeneration. It refers to the main problems associated with this process, which cover the spatial, economic and social sides of the city. It discusses the use of art in the humanisation of a place, improving its attractiveness and promoting modern solutions in architecture and urban planning. The process of holistic, systemic urban planning-related transformations of a decayed area has covered improving the accessibility of the site and the placement of a structure that crystallised the spatial layout. The success of this programme can constitute an indication for other centres affected by the necessity to introduce functional and spatial changes, as well as an effective municipal policy.

Mots clés

  • Bilbao
  • urban regeneration
  • transformations
  • space
  • accessibility
  • art
Accès libre

Zakopane – in Defence of Cultural Landscape – Clerks’ Parcels

Publié en ligne: 21 May 2020
Pages: 51 - 59

Résumé

Abstract

This article addresses the issue of cultural values regarding the need to protect one of the housing estates in Zakopane – known as the Clerks’ Parcels. From the north-west the area is enclosed by Sabały St., from the west by Piłsudskiego St., from the south by Czecha St., and on the east side it borders on the Faluszowy Brook. It was designed and shaped during the 1920s according to the project of the renowned architect, Karol Stryjeński. The Clerks’ Parcels area is not merely a defined, consciously shaped urban layout, but also culturally significant objects listed in the heritage register and entered in the district monument records. In the opinion of the authors of this article, the area deserves to be under a statutory form of protection, namely listed in the immovable monument register of the Lesser Poland Voivodeship, which would safeguard that space against degradation and cultural annihilation.

Mots clés

  • Zakopane
  • Clerks’ Parcels
  • urban layout of Zakopane
Accès libre

The Influence of the Development of Private Air Communication on the Architecture and Urban Planning of the 21st Century

Publié en ligne: 21 May 2020
Pages: 61 - 73

Résumé

Abstract

In the first part, the article describes the stages of the development of gyroplanes and the influence of wartime policy on the interest in light aircraft. Also presented are links and the possibilities of using gyroplanes in various sectors of the economy. The authors, based on source texts, present the current position of the aviation industry in the Polish economy and attempt to diagnose its development capabilities. As a result, factors responsible for the current condition of the light aviation industry and its links with architecture and urban planning are submitted. The question is posed: what consequences will the development of the aviation industry bring for architecture and urban planning, for the community and the image of 21st century cities?

Mots clés

  • metropolitan transport
  • urban planning
  • urban mobility
  • urban airspace
  • landing areas
  • helipads
  • high-rise buildings
  • ultra-light aviation
  • helicopters
  • gyroplanes
  • architecture
  • future of aviation
  • personal aviation
  • air traffic control
Accès libre

Comparative Analysis of the Coarse Aggregate Shapes used to Manufacturing High Performance Self-Compacting Concrete

Publié en ligne: 21 May 2020
Pages: 75 - 86

Résumé

Abstract

The influence of the shape of coarse aggregate on the properties of fresh concrete mixes, and the strength of high-performance self-compacting concrete (HPSCC) is important issue. In this study, irregular and regular grains were separated from the basalt, porphyry and granite coarse aggregate. The shape of these grains was determining using digital image analysis and was in accordance with the European Standard [19]. The aspect ratio (AR) and roundness (R) were ascertained in order to highlight the differences in the coarse aggregate shape used the design HPSCC. The study indicates that using the same crushing system, varied parameters of the shape of coarse aggregates were obtained. It was determined that the best fitting distribution for aspect ratio and roundness at a 95% confidence level is the generalised extreme value distribution.

Mots clés

  • coarse aggregate
  • shape
  • computer image analysis
  • self-compacting concrete
Accès libre

Control of the Vibration Structure Induced during Works with the use of Explosives

Publié en ligne: 21 May 2020
Pages: 87 - 99

Résumé

Abstract

This article presents the results of research on controlling the structure of vibrations induced during the firing of explosives with the use of non-electrical and electronic systems and the influence of the vibration structure during a transition from the ground to the building. The use of procedures associated with the selection of millisecond delay for firing explosive charges during blasting allows to get the excitation of favourable structure vibrations, thanks to a strong damping which is obtained at the transition from the ground to the structure. This means that optimally designed blasting works do not have to limit the mass of the explosives in the borehole as well as their number.

Mots clés

  • Open-pit mining
  • blasting technique
  • millisecond blasting
  • vibration structure
  • impact of vibrations on buildings
Accès libre

Transport Attractiveness of Shopping Malls

Publié en ligne: 21 May 2020
Pages: 101 - 112

Résumé

Abstract

The dynamic development of analytical methods used for the modelling of town travel increases the demand for various kinds of data necessary to estimate the road traffic volume on transport networks. The estimation of traffic volume generated by particular facilities located in a city is an important element of modelling. Among these facilities, large shopping malls are considered to be one of the most significant road traffic generators. The estimation of transport attractiveness of such large objects is a big challenge in modelling customers’ journey to large shopping malls. In this study, a new method is proposed for the assessment of transport attractiveness of large trade and service facilities.

Mots clés

  • shopping malls
  • attractiveness
  • road traffic modelling
Accès libre

The Evaluation of Control Quality in Automatic Systems Based on Maximum Error

Publié en ligne: 21 May 2020
Pages: 113 - 120

Résumé

Abstract

The article presents an approach that uses the value of the maximum error to assess the quality of control in automatic control systems. The integral-square-error criterion is analysed together with the signals that enable its derivation. Signals with two constraints are considered.

Mots clés

  • Control error
  • integral-square criterion
  • maximising signals
  • constraints of signals
Accès libre

The Application of Non-Standard GPR Techniques for the Examination of River Dikes

Publié en ligne: 21 May 2020
Pages: 121 - 138

Résumé

Abstract

A standard measurement procedure currently applied in the ground penetrating radar (GPR) method is short-offset reflection profiling. As this procedure delivers data that is suited only for qualitative interpretation, its application should be limited exclusively to reconnaissance surveys. There are various other techniques used in GPR surveying that may be regarded as non-standard, such as multi-offset and adaptable-polarisation surveying and tomography. Because these techniques deliver information that allows for quantitative interpretation, they could be applied for the detailed examination of geological media and investigations of various buried anthropogenic targets. This paper focuses on the application of non-standard GPR techniques for the detection of high-porosity zones in river dikes. REsults from both field surveys and numerical modelling are presented.

Mots clés

  • GPR
  • ground penetrating radar
  • non-standard surveys
  • river dike
Accès libre

A Prototype of a Small Stirling Refrigeration Unit

Publié en ligne: 21 May 2020
Pages: 139 - 151

Résumé

Abstract

This paper presents original mathematical models which can be used for the size optimization of particular elements in the design process of cooling appliances using the Stirling cycle. The models were used to design a prototype of the Stirling cooling device. The project employs a unique piston–cylinder kinematic pair which enables dry fiction work. Original platelet and ball ceramic regenerators were designed. The presented model assumes adiabatic transformations of the medium in the cylinders as this approach yields more realistic results in comparison to a simple isothermal Schmidt analysis. One cycle of the device (one rotation of the shaft) is divided into elementary angles Φ, where the state of the gas is considered as constant. As a result, states of the gas in individual components of the working space are determined in any given, discrete time steps of the Stirling cycle.

Mots clés

  • Stirling cycle
  • Stirling engine
  • Stirling cooler
  • Stirling cycle numerical modelling
  • optimisation of Stirling engine
  • cogeneration
  • heat transfer
Accès libre

A Note On Browkin’s and Cao’s Cancellation Algorithm

Publié en ligne: 21 May 2020
Pages: 153 - 165

Résumé

Abstract

In this paper, we follow our generalisation of the cancellation algorithm described in our previous paper [A. Tomski, M. Zakarczemny, On some cancellation algorithms, NNTDM. 23, 2017, p. 101–114]. for f being a natural-valued function defined on ℕs s, ≥1 we remove the divisors of all possible values of f in the points in which the sum of coordinates is less than or equal to n. The least non-cancelled number is called the discriminator Df(n). We find formulas, or at least an estimation for this discriminator, in the case of a broad class of sequences.

Mots clés

  • discriminator
  • sequence
  • congruence
  • odious numbers
  • Thue-Morse sequence
Accès libre

Two-Dimensional Numerical Simulation of a Thermoelectric Cooler Module

Publié en ligne: 21 May 2020
Pages: 167 - 178

Résumé

Abstract

The paper presents the methodology and results of a numerical simulation of coupled thermal and electrical phenomena in a thermoelectric (TE) cooler module obtained with the MOOSE Framework released by Idaho National Laboratory. The coupled system of partial differential equations is solved for the value of electric potential and temperature fields. Equations include contributions from electric conduction, Seebeck effect, thermal conduction, Joule heating as well as Peltier and Thomson effects. The values of the cooling capacity and the voltage drop of the module are calculated and compared with the data provided by the manufacturer of the thermoelectric cooler in order to determine if the simplified assumptions adopted in the numerical model are appropriate to reliably infer about the performance of the TE module composed of over one hundred thermoelectric pairs.

Mots clés

  • thermoelectrics
  • Peltier effect
  • Thomson effect
  • Seebeck effect
  • numerical simulation
  • MOOSE
Accès libre

Numerical Simulation of Temperature Distribution during the First Stage of the Friction Stir Alloying Process

Publié en ligne: 21 May 2020
Pages: 179 - 190

Résumé

Abstract

This work demonstrates the numerical modelling of thermal dispersion accompanying the first stage of the friction stir alloying process. It is very important to recognise the temperature field in the modified workpiece in order to identify the zones where the physical material properties are changing. The temperature gradient leads to a drop of yield strength of the material and, as a consequence, the occurrence of the possibility of plastic flow around the tool. An attempt has been made to analyse the axisymmetric thermal problem described by a Fourier equation with an internal heat source in which the heat is derived only from work of frictional forces occurring between the workpiece and the tool material. The example under consideration focuses on the production of an Al-TiC composite using FSA technology. Macrostructure images of the composite and the simulation results confirm the correctness of the applied mathematical model, where the obtained temperature field corresponds with specific FSA zones.

Mots clés

  • FSA
  • temperature field
  • Al-TiC composite
Accès libre

The Microstructure and Properties of Titanium Carbide Reinforced Stainless Steel Matrix Composites Prepared by Powder Metallurgy

Publié en ligne: 21 May 2020
Pages: 191 - 206

Résumé

Abstract

TiC particle-reinforced AISI 316l stainless-steel matrix composites were prepared using conventional powder metallurgy technology. The effect of TiC content on the microstructure and properties of these composites has been investigated with a particular emphasis upon hardness, wear resistance and corrosion resistance in sea water environments. The results showed that TiC particle reinforcement improved the hardness, wear resistance and corrosion resistance of AISI 316l stainless steel. The higher TiC content in the studied composites resulted in a higher hardness of the wear surface and a lower wear rate. The best corrosion resistance in sea water was achieved for sintered AISI 316l – 5% TiC composite.

Mots clés

  • metal matrix composites
  • TiC particles
  • AISI 316L
  • density
  • hardness
  • wear resistance
  • corrosion resistance
  • microstructure

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