Pub Date : 2023-09-22DOI: 10.24840/2183-6493_009-004_001131
Alla Suseela, SS. Asadi
Snail shells are the discarded bio-shell waste from restaurants, and oceans creating huge environmental problems for society. Living organisms are harmed when these shells are released. As previously stated, the work focuses primarily on the utilisation of snail shell powder as a raw ingredient in cement mortar. The mechanical and durability features of snail shell-based cement mortar were compared to the nominal mortar in this study. Snail shell powder, ranging from 0% to 35%, was used to partially substitute cement in mortar, with a variation of 5%. XRD (X-Ray Diffraction) was used to determine the chemical composition of both mixes. The mechanical properties of mortar for both mixes were determined using a compressive strength test. The tests on cement mortar viz., Water Absorption, Sorptivity, Acid Durability, and Rapid Chloride Permeability Test (RCP Test) were compared with nominal mortar mix. According to the results of the investigation, the optimum use of snail shell powder is 30%. The durability of both mixes increased by the increase of the snail shell powder. To detect the C-S-H gel formations, microstructural analysis was performed for both mixes.
{"title":"Experimental Investigation of Snail Shell-based Cement Mortar: Mechanical Strength, Durability and Microstructure","authors":"Alla Suseela, SS. Asadi","doi":"10.24840/2183-6493_009-004_001131","DOIUrl":"https://doi.org/10.24840/2183-6493_009-004_001131","url":null,"abstract":"Snail shells are the discarded bio-shell waste from restaurants, and oceans creating huge environmental problems for society. Living organisms are harmed when these shells are released. As previously stated, the work focuses primarily on the utilisation of snail shell powder as a raw ingredient in cement mortar. The mechanical and durability features of snail shell-based cement mortar were compared to the nominal mortar in this study. Snail shell powder, ranging from 0% to 35%, was used to partially substitute cement in mortar, with a variation of 5%. XRD (X-Ray Diffraction) was used to determine the chemical composition of both mixes. The mechanical properties of mortar for both mixes were determined using a compressive strength test. The tests on cement mortar viz., Water Absorption, Sorptivity, Acid Durability, and Rapid Chloride Permeability Test (RCP Test) were compared with nominal mortar mix. According to the results of the investigation, the optimum use of snail shell powder is 30%. The durability of both mixes increased by the increase of the snail shell powder. To detect the C-S-H gel formations, microstructural analysis was performed for both mixes.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136060329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-22DOI: 10.24840/2183-6493_009-004_001945
Luigi Solazzi, Nicola Danzi
The present research concerns the evaluation of the dynamic effect on lattice boom cranes. The dynamic actions involved in this research are: wind, moving load and earthquake, assumed as time-varying actions. The research starts with the design of a large crane by adopting classical standards for these structures (UNI EN 13001 series). The elaborations were performed by analytical methods followed by solid model building and finite element analysis (Solidworks® and Ansys® software). The next step was to define the aforementioned loads acting on these structures. The wind action model was compared with the static approach. Payload displacement induces high-intensity actions on the crane structure; to better understand these effects, several load curves were simulated. The last action considered is the earthquake phenomenon, which is not usually adopted to design this type of structure.
本文研究的是格架吊车的动力效应评价问题。本研究涉及的动力作用有:风、移动荷载和地震，假定为时变作用。研究从大型起重机的设计开始，采用这些结构的经典标准(UNI EN 13001系列)。通过分析方法进行详细阐述，然后进行实体模型构建和有限元分析(Solidworks®和Ansys®软件)。下一步是定义上述作用在这些结构上的载荷。将风的作用模型与静力法进行了比较。载荷位移对起重机结构产生高强度作用;为了更好地理解这些影响，模拟了几个负载曲线。最后考虑的作用是地震现象，在设计这类结构时通常不采用地震现象。
{"title":"Dynamic effects on the lattice boom crane due to the wind, moving load and earthquake events","authors":"Luigi Solazzi, Nicola Danzi","doi":"10.24840/2183-6493_009-004_001945","DOIUrl":"https://doi.org/10.24840/2183-6493_009-004_001945","url":null,"abstract":"The present research concerns the evaluation of the dynamic effect on lattice boom cranes. The dynamic actions involved in this research are: wind, moving load and earthquake, assumed as time-varying actions. The research starts with the design of a large crane by adopting classical standards for these structures (UNI EN 13001 series). The elaborations were performed by analytical methods followed by solid model building and finite element analysis (Solidworks® and Ansys® software). The next step was to define the aforementioned loads acting on these structures. The wind action model was compared with the static approach. Payload displacement induces high-intensity actions on the crane structure; to better understand these effects, several load curves were simulated. The last action considered is the earthquake phenomenon, which is not usually adopted to design this type of structure.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136061309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-22DOI: 10.24840/2183-6493_009-004_001741
Hassan Abdolpour, Paweł Niewiadomski, Łukasz Sadowski, Arkadiusz Kwiecień
The main aim of the present study is to design an innovative self-compacting material modified with recycled steel fibers (RSF) from waste tires and spent equilibrium catalyst (Ecat) from the petrochemical industry for ultra-high performance application. For this purpose, 17 different mixtures were developed and analysed using different percentages of RSF (0%-3%) and replacement of cement by different percentages of Ecat (0%-15%).
The developed mortars' self-compatibility was evaluated in a fresh stage using mini-cone tests. Regarding the hardened stage, the mortars were characterized at the ages of 7 days and 28 days using compression and unnotched flexural tests. The abilities of RSF to increase the post-cracking behavior of the specimens and to use Ecat to increase the bond performance between RSF and the cement matrix were assessed by performing notched three-point bending tests. The results of notched flexural tests were used to obtain the residual flexural strength in service limit state (SLS), ultimate limit state (ULS), and two equivalent flexural strengths.
The experimental results for the fresh stage demonstrated that inclusion of RSF and Ecat significantly reduced the workability of mortars. The beneficial use of RSF and Ecat was observed to increase compressive strength and flexural strength for 7 days and 28 days of tested specimens. Notched flexural tested specimens showed that the addition of RSF and Ecat can significantly decrease the brittle behavior of cement-based materials by improving its toughness and post-cracking resistance. Middle-span deflection, crack initiation load, and ultimate flexural load were also increased with the addition of RSF and Ecat. In this sense, the results of this research showed that RSF and Ecat seem to have the potential to constitute a sustainable material for structural and nonstructural applications.
{"title":"Design of an innovative self-compacting material modified with recycled steel fibers and spent equilibrium catalyst for ultra-high performance applications","authors":"Hassan Abdolpour, Paweł Niewiadomski, Łukasz Sadowski, Arkadiusz Kwiecień","doi":"10.24840/2183-6493_009-004_001741","DOIUrl":"https://doi.org/10.24840/2183-6493_009-004_001741","url":null,"abstract":"The main aim of the present study is to design an innovative self-compacting material modified with recycled steel fibers (RSF) from waste tires and spent equilibrium catalyst (Ecat) from the petrochemical industry for ultra-high performance application. For this purpose, 17 different mixtures were developed and analysed using different percentages of RSF (0%-3%) and replacement of cement by different percentages of Ecat (0%-15%).
 The developed mortars' self-compatibility was evaluated in a fresh stage using mini-cone tests. Regarding the hardened stage, the mortars were characterized at the ages of 7 days and 28 days using compression and unnotched flexural tests. The abilities of RSF to increase the post-cracking behavior of the specimens and to use Ecat to increase the bond performance between RSF and the cement matrix were assessed by performing notched three-point bending tests. The results of notched flexural tests were used to obtain the residual flexural strength in service limit state (SLS), ultimate limit state (ULS), and two equivalent flexural strengths.
 The experimental results for the fresh stage demonstrated that inclusion of RSF and Ecat significantly reduced the workability of mortars. The beneficial use of RSF and Ecat was observed to increase compressive strength and flexural strength for 7 days and 28 days of tested specimens. Notched flexural tested specimens showed that the addition of RSF and Ecat can significantly decrease the brittle behavior of cement-based materials by improving its toughness and post-cracking resistance. Middle-span deflection, crack initiation load, and ultimate flexural load were also increased with the addition of RSF and Ecat. In this sense, the results of this research showed that RSF and Ecat seem to have the potential to constitute a sustainable material for structural and nonstructural applications.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136061313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-21DOI: 10.24840/2183-6493_009-002_002081
Lara Costa Bomfim, S. Santos Cruz
Individuals react differently when moving in urban spaces, as their senses are distinctively activated. Their interpretations and how the built environment is perceived result in different meanings. When studying public spaces, it is of utmost importance to understand how residents and visitors construct images of the city, by perceiving and appropriating urban spaces. In particular, this is decisive when designing Pedestrian Wayfinding Systems (PWS) in urban areas. Based on spatial cognition studies, this paper identifies and explores the main aspects influencing the design of wayfinding systems. The study is structured in three main parts. First, the article reviews literature on spatial cognition and human behaviors. Second, it analyzes some reference cases considered good practices for PWS, their implementation in contemporary public spaces, and their visual and aesthetic forms of expression. Third, it develops a practical guide for designing a PWS focused on end-users. More specifically, the research aims to support the municipality of Porto in defining the tender specifications for the development of a PWS, to be included in the future Integrated Signage and Information System. Ultimately, this study proposes recommendations to improve pedestrian navigation in the urban context and help decision-makers, designers, and urban planners potentially create better wayfinding systems in the future.
{"title":"Understanding Spatial Cognition for Designing Pedestrian Wayfinding Systems","authors":"Lara Costa Bomfim, S. Santos Cruz","doi":"10.24840/2183-6493_009-002_002081","DOIUrl":"https://doi.org/10.24840/2183-6493_009-002_002081","url":null,"abstract":"Individuals react differently when moving in urban spaces, as their senses are distinctively activated. Their interpretations and how the built environment is perceived result in different meanings. When studying public spaces, it is of utmost importance to understand how residents and visitors construct images of the city, by perceiving and appropriating urban spaces. In particular, this is decisive when designing Pedestrian Wayfinding Systems (PWS) in urban areas. \u0000Based on spatial cognition studies, this paper identifies and explores the main aspects influencing the design of wayfinding systems. The study is structured in three main parts. First, the article reviews literature on spatial cognition and human behaviors. Second, it analyzes some reference cases considered good practices for PWS, their implementation in contemporary public spaces, and their visual and aesthetic forms of expression. Third, it develops a practical guide for designing a PWS focused on end-users. More specifically, the research aims to support the municipality of Porto in defining the tender specifications for the development of a PWS, to be included in the future Integrated Signage and Information System. \u0000Ultimately, this study proposes recommendations to improve pedestrian navigation in the urban context and help decision-makers, designers, and urban planners potentially create better wayfinding systems in the future.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80696316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-10DOI: 10.24840/2183-6493_009-002_002207
Hasan Mansour, F. B. Alves, A. Costa
Despite the inherently dynamic nature of the urban identity concept and its interconnections among various academic disciplines, including philosophy, psychology, environmental studies, and urbanism, the term is employed in distinct contexts within each field. This divergence in usage has resulted in ambiguity and a lack of clarity regarding the meaning of urban identity. This research aims to scrutinize the existing literature on identity and urban identity across various scientific disciplines, reaching a better understanding of the term. As a methodological approach, we undertake a systematic analysis of the theoretical debate to identify and comprehend the descriptive and analytical perspectives on identity and urban identity concepts, the evaluation processes of urban identity, and the identification of primary debates, issues, and related gaps. The findings of this research will facilitate a more comprehensive understanding of the urban identity concept and its identification, thereby contributing to the evolution of academic research on urban identity.
{"title":"The Challenges in Understanding Urban Identity","authors":"Hasan Mansour, F. B. Alves, A. Costa","doi":"10.24840/2183-6493_009-002_002207","DOIUrl":"https://doi.org/10.24840/2183-6493_009-002_002207","url":null,"abstract":"Despite the inherently dynamic nature of the urban identity concept and its interconnections among various academic disciplines, including philosophy, psychology, environmental studies, and urbanism, the term is employed in distinct contexts within each field. This divergence in usage has resulted in ambiguity and a lack of clarity regarding the meaning of urban identity. \u0000This research aims to scrutinize the existing literature on identity and urban identity across various scientific disciplines, reaching a better understanding of the term. \u0000As a methodological approach, we undertake a systematic analysis of the theoretical debate to identify and comprehend the descriptive and analytical perspectives on identity and urban identity concepts, the evaluation processes of urban identity, and the identification of primary debates, issues, and related gaps. The findings of this research will facilitate a more comprehensive understanding of the urban identity concept and its identification, thereby contributing to the evolution of academic research on urban identity.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89814099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-28DOI: 10.24840/2183-6493_009-003_001845
Marina Mergulhão, Sofia Magalhães, J. M. Costa
The evaluation of product cycles has allowed companies to transition from linear to circular production and reuse collected material. However, recycling is only sometimes straightforward and involves the material history of thermal cycles, the recycled content, and other characteristics. Therefore, recycling processes’ adversities and products need to be studied. Thus, this study aims to obtain a recycled Onyx filament, a micro carbon fiber-filled nylon, and evaluate its recycling potential to produce 3D printed samples. Tensile tests, optical microscopy, and evaluation of the quality of 3D printed samples and filaments were conducted. Under the studied conditions, the recycled Onyx filament did not present a satisfactory performance for 3D Printing, leading to nozzle clogs and precluding the 3D printed samples from being completed. These problems have been related to previous work. Therefore, it is necessary to investigate Onyx recycling under other conditions, such as recycling conditions or adding virgin material during recycling.
{"title":"Recycling Potential of Onyx Composite for Additive Manufacturing","authors":"Marina Mergulhão, Sofia Magalhães, J. M. Costa","doi":"10.24840/2183-6493_009-003_001845","DOIUrl":"https://doi.org/10.24840/2183-6493_009-003_001845","url":null,"abstract":"The evaluation of product cycles has allowed companies to transition from linear to circular production and reuse collected material. However, recycling is only sometimes straightforward and involves the material history of thermal cycles, the recycled content, and other characteristics. Therefore, recycling processes’ adversities and products need to be studied. Thus, this study aims to obtain a recycled Onyx filament, a micro carbon fiber-filled nylon, and evaluate its recycling potential to produce 3D printed samples. Tensile tests, optical microscopy, and evaluation of the quality of 3D printed samples and filaments were conducted. Under the studied conditions, the recycled Onyx filament did not present a satisfactory performance for 3D Printing, leading to nozzle clogs and precluding the 3D printed samples from being completed. These problems have been related to previous work. Therefore, it is necessary to investigate Onyx recycling under other conditions, such as recycling conditions or adding virgin material during recycling.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84322428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-28DOI: 10.24840/2183-6493_009-003_001808
Mahmoud Karaz, J. C. Teixeira
Construction waste (CW) is an abstract, high-level concept and difficult to measure systematically. The conventional management methods have failed to translate the reality in the construction industry context. The integrated Lean Construction (LC) and Building Information Modelling (BIM) streamline several proactive and collaborative solutions to address CW at its source across the whole asset lifecycle. This paper adopts the systematic literature review method to (i) understand ‘waste’ and ‘waste elimination’ concepts through LC perspectives and (ii) to review factors of LC-BIM for waste elimination. Based on thematic analysis applied to 54 relevant documents in the Scopus and IGLC databases, some literature was approached. According to thematic analysis applied to the existing LC-BIM approaches, despite the potential of LC-BIM for CW elimination, the current literature lacks the concept of waste elimination in the number and content of publications. The paper highlights some generic recommendations for future theoretical and empirical developments.
{"title":"Waste Elimination based on Lean Construction and Building Information Modelling: A Systematic Literature Review","authors":"Mahmoud Karaz, J. C. Teixeira","doi":"10.24840/2183-6493_009-003_001808","DOIUrl":"https://doi.org/10.24840/2183-6493_009-003_001808","url":null,"abstract":"Construction waste (CW) is an abstract, high-level concept and difficult to measure systematically. The conventional management methods have failed to translate the reality in the construction industry context. The integrated Lean Construction (LC) and Building Information Modelling (BIM) streamline several proactive and collaborative solutions to address CW at its source across the whole asset lifecycle. This paper adopts the systematic literature review method to (i) understand ‘waste’ and ‘waste elimination’ concepts through LC perspectives and (ii) to review factors of LC-BIM for waste elimination. Based on thematic analysis applied to 54 relevant documents in the Scopus and IGLC databases, some literature was approached. According to thematic analysis applied to the existing LC-BIM approaches, despite the potential of LC-BIM for CW elimination, the current literature lacks the concept of waste elimination in the number and content of publications. The paper highlights some generic recommendations for future theoretical and empirical developments.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88805255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-28DOI: 10.24840/2183-6493_009-003_001962
Cauê Rios, Cecília Silva
Environmental issues and sustainability are inherent parameters of mobility. The environmental emergency has influenced the paradigms of transport to give rise to new sustainable discourses. Changing of signifying patterns suggests transfiguring the discourses of what was in force. Thus, the main objective of this research is to understand the set of institutional characteristics that can be related to motivate the agents to have a more or less favorable attitudinal stages towards the sustainable mobility. To this end, a theoretical contribution on governance, institutional work and sustainable mobility is used to understand the institutional mechanisms focused on mobility planning. The Attitudinal Stages method is at the core of the research on the more or less favorable planners’ cycling attitudes. As a result of the interpolation of the methods, it will be verify whether there is a relationship between certain characteristics of institutional functioning and the planners attitudes.
{"title":"Bicycle mobility","authors":"Cauê Rios, Cecília Silva","doi":"10.24840/2183-6493_009-003_001962","DOIUrl":"https://doi.org/10.24840/2183-6493_009-003_001962","url":null,"abstract":"Environmental issues and sustainability are inherent parameters of mobility. The environmental emergency has influenced the paradigms of transport to give rise to new sustainable discourses. Changing of signifying patterns suggests transfiguring the discourses of what was in force. Thus, the main objective of this research is to understand the set of institutional characteristics that can be related to motivate the agents to have a more or less favorable attitudinal stages towards the sustainable mobility. To this end, a theoretical contribution on governance, institutional work and sustainable mobility is used to understand the institutional mechanisms focused on mobility planning. The Attitudinal Stages method is at the core of the research on the more or less favorable planners’ cycling attitudes. As a result of the interpolation of the methods, it will be verify whether there is a relationship between certain characteristics of institutional functioning and the planners attitudes.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81252868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-28DOI: 10.24840/2183-6493_009-003_001645
B. V, Chandra Shekhar Reddy Atla, M.R.Shivakumar
Maintaining voltage stability is an important factor in modern power system study and operation. Supplementing the system with reactive power (VAr) support devices such as FACTS helps to overcome voltage instability issues. Commonly, dynamic optimization based method is employed to study the dynamic Voltage Stability Analysis (VSA) of the system. The existing dynamic optimization approach has dependencies on the availability of specific tools and the FACTS model to perform dynamic VSA. Besides, the application of the existing method for the voltage collapse phenomenon is not addressed in detail. It is desirable to have a generic dynamic VSA approach that does not have dependencies on specific tools and the FACTS model. This paper proposes a new generic approach to carry-out dynamic VSA with any given DAE tool. A method of emulating the FACTS device’s behaviour for dynamic VAr injection is introduced using an incremental optimization approach. A generic interface is newly developed as a Modifiable Off The Shelf (MOTS) component to couple the DAE solver and optimization solver. The existing approach is enhanced into a generic dynamic optimization framework by integrating incremental optimization technique and the generic interface. Voltage collapse phenomenon on IEEE-9 bus system is investigated employing the enhanced framework. Post contingency behaviour of the system illustrates the successful mitigation of voltage collapse issues. Obtained results show the effectiveness of the new generic approach in performing dynamic VSA.
{"title":"Power System Voltage Collapse Mitigation Employing Optimization Based Dynamic Voltage Stability Analysis","authors":"B. V, Chandra Shekhar Reddy Atla, M.R.Shivakumar","doi":"10.24840/2183-6493_009-003_001645","DOIUrl":"https://doi.org/10.24840/2183-6493_009-003_001645","url":null,"abstract":"Maintaining voltage stability is an important factor in modern power system study and operation. Supplementing the system with reactive power (VAr) support devices such as FACTS helps to overcome voltage instability issues. Commonly, dynamic optimization based method is employed to study the dynamic Voltage Stability Analysis (VSA) of the system. The existing dynamic optimization approach has dependencies on the availability of specific tools and the FACTS model to perform dynamic VSA. Besides, the application of the existing method for the voltage collapse phenomenon is not addressed in detail. It is desirable to have a generic dynamic VSA approach that does not have dependencies on specific tools and the FACTS model. This paper proposes a new generic approach to carry-out dynamic VSA with any given DAE tool. A method of emulating the FACTS device’s behaviour for dynamic VAr injection is introduced using an incremental optimization approach. A generic interface is newly developed as a Modifiable Off The Shelf (MOTS) component to couple the DAE solver and optimization solver. The existing approach is enhanced into a generic dynamic optimization framework by integrating incremental optimization technique and the generic interface. Voltage collapse phenomenon on IEEE-9 bus system is investigated employing the enhanced framework. Post contingency behaviour of the system illustrates the successful mitigation of voltage collapse issues. Obtained results show the effectiveness of the new generic approach in performing dynamic VSA.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90367554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-28DOI: 10.24840/2183-6493_009-003_001493
José Maria Carvalho Belo Ximenes, Carlos de Jesus, J. Aguiar
The principles of this work are the study of masonry materials with a view to the conservation and rehabilitation of buildings. It is important to preserve and care for the historical heritage. Development and associated innovation require knowledge of the physical and mechanical characteristics of materials.Situational causes of pathologies found in stone masonry can be identified by the photographs presented, showing a horizontal cracking due to physical natural actions, temperature variations and the presence of water.The main causes of pathological changes are air pollution, but the water and the temperature also play a very important role in the development of the deterioration.The test results are essential to obtain the quality and durability of the materials of the limestone and mortar to prevent damage the water in the environment with the incorporation of paint with good quality.
{"title":"Surface pathology on the walls of limestone and mortar masonry","authors":"José Maria Carvalho Belo Ximenes, Carlos de Jesus, J. Aguiar","doi":"10.24840/2183-6493_009-003_001493","DOIUrl":"https://doi.org/10.24840/2183-6493_009-003_001493","url":null,"abstract":"The principles of this work are the study of masonry materials with a view to the conservation and rehabilitation of buildings. It is important to preserve and care for the historical heritage. Development and associated innovation require knowledge of the physical and mechanical characteristics of materials.Situational causes of pathologies found in stone masonry can be identified by the photographs presented, showing a horizontal cracking due to physical natural actions, temperature variations and the presence of water.The main causes of pathological changes are air pollution, but the water and the temperature also play a very important role in the development of the deterioration.The test results are essential to obtain the quality and durability of the materials of the limestone and mortar to prevent damage the water in the environment with the incorporation of paint with good quality.","PeriodicalId":36339,"journal":{"name":"U.Porto Journal of Engineering","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82257029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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