One objective of gifted education is to provide fair opportunities for all children, including access to the nomination and selection procedures for gifted programs and services. This study aims to identify invisible biases in the nomination of gifted students in the National Gifted Identification Project (Mawhiba Test) during the periods of 2014, 2015, and 2017. The participants were limited to students nominated in Al Ahsa, in the Eastern Province of Saudi Arabia, which includes students from rural, urban, and settlement schools. There was a total sample of 74,199 male students and 74,097 female students. The study followed the descriptive approach, and the Chi-square test was used to measure whether the location variable (i.e., the school’s location) was independent of the number of candidates. The results showed a significant correlation between the location and the number of male and female candidates. Additionally, the results indicated a significant decrease in the percentage of male and female students in settlement schools, which requires the relevant authorities to reconsider the procedures followed in nomination and selection, especially in remote areas and settlements. KEYWORDS Gifted students, disadvantaged students, rural, urban, settlement schools, Mawhiba Test, underrepresentation
{"title":"Invisible Bias in Nominating and Selecting Gifted Students","authors":"A. Aljughaiman, Waleed Albosaif","doi":"10.37575/h/edu/210073","DOIUrl":"https://doi.org/10.37575/h/edu/210073","url":null,"abstract":"One objective of gifted education is to provide fair opportunities for all children, including access to the nomination and selection procedures for gifted programs and services. This study aims to identify invisible biases in the nomination of gifted students in the National Gifted Identification Project (Mawhiba Test) during the periods of 2014, 2015, and 2017. The participants were limited to students nominated in Al Ahsa, in the Eastern Province of Saudi Arabia, which includes students from rural, urban, and settlement schools. There was a total sample of 74,199 male students and 74,097 female students. The study followed the descriptive approach, and the Chi-square test was used to measure whether the location variable (i.e., the school’s location) was independent of the number of candidates. The results showed a significant correlation between the location and the number of male and female candidates. Additionally, the results indicated a significant decrease in the percentage of male and female students in settlement schools, which requires the relevant authorities to reconsider the procedures followed in nomination and selection, especially in remote areas and settlements. KEYWORDS Gifted students, disadvantaged students, rural, urban, settlement schools, Mawhiba Test, underrepresentation","PeriodicalId":39024,"journal":{"name":"Scientific Journal of King Faisal University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89164617","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}
This paper critically reviews and observes the nature of contemporary careers and the orientation in which careers research has advanced over the past decade. The contemporary concept of career refers to an individual’s pursuit of career advancement without being restricted to a single job in a single company. Specifically, career concepts that appeared in the 1990s, including the protean and boundaryless career frameworks, and the next generation of career concept, including integrative frameworks, hybrid careers, and the kaleidoscope career model, are discussed. These models and theories all focus on the change in the concept of career management for individuals. This change occurred because of the developments taking place in this era, including economic aspects, globalization, and technology. This review aims to improve our understanding of careers in today’s dynamic work environment, especially after the COVID-19 pandemic and the rapid changes that Saudi Arabia is witnessing at all levels. The challenges facing individuals in career advancement during this period are different from previous ones, so researchers should study the effects of the pandemic on changing the behavior of individuals towards the concept of career management. This review provides a comprehensive discussion of current theories and offers major questions for future research.
{"title":"Contemporary Career Theories in the Light of the COVID-19 Pandemic: A Critical Literature Review","authors":"Abdulrahman Alshaikhmubarak","doi":"10.37575/h/mng/210076","DOIUrl":"https://doi.org/10.37575/h/mng/210076","url":null,"abstract":"This paper critically reviews and observes the nature of contemporary careers and the orientation in which careers research has advanced over the past decade. The contemporary concept of career refers to an individual’s pursuit of career advancement without being restricted to a single job in a single company. Specifically, career concepts that appeared in the 1990s, including the protean and boundaryless career frameworks, and the next generation of career concept, including integrative frameworks, hybrid careers, and the kaleidoscope career model, are discussed. These models and theories all focus on the change in the concept of career management for individuals. This change occurred because of the developments taking place in this era, including economic aspects, globalization, and technology. This review aims to improve our understanding of careers in today’s dynamic work environment, especially after the COVID-19 pandemic and the rapid changes that Saudi Arabia is witnessing at all levels. The challenges facing individuals in career advancement during this period are different from previous ones, so researchers should study the effects of the pandemic on changing the behavior of individuals towards the concept of career management. This review provides a comprehensive discussion of current theories and offers major questions for future research.","PeriodicalId":39024,"journal":{"name":"Scientific Journal of King Faisal University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86928329","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}
This study aims to investigate the psychological impact of the Saudi low variety (henceforth, it will be referred to as “SLV”) in enticing prospective customers to their commercial products or services. It proceeds from a premise that the marketing messages employed by business providers massively influences our opinions about a product or a business establishment. In order to validate such a view, 80 native speakers of SLV, representing 2 groups of simple (regular consumers) and stratified (advertisers) samplings, participated in the study. Each group consisted of 40 subjects. They were requested to fill out a questionnaire that included two questions; each question included 10 options, representing high (Modern Standard Arabic) and SLV. The findings from the data analysis reveal that the marketing message code conveyed in SLV influences customers’ and business providers’ selling and purchasing inclinations and preferences. KEYWORDS Low variety, high variety, marketing, code choice, psychology, language variation
{"title":"The Influence of the Low Variety in Advertisements: The Saudi Context","authors":"Yasir Alasiri","doi":"10.37575/h/lng/220009","DOIUrl":"https://doi.org/10.37575/h/lng/220009","url":null,"abstract":"This study aims to investigate the psychological impact of the Saudi low variety (henceforth, it will be referred to as “SLV”) in enticing prospective customers to their commercial products or services. It proceeds from a premise that the marketing messages employed by business providers massively influences our opinions about a product or a business establishment. In order to validate such a view, 80 native speakers of SLV, representing 2 groups of simple (regular consumers) and stratified (advertisers) samplings, participated in the study. Each group consisted of 40 subjects. They were requested to fill out a questionnaire that included two questions; each question included 10 options, representing high (Modern Standard Arabic) and SLV. The findings from the data analysis reveal that the marketing message code conveyed in SLV influences customers’ and business providers’ selling and purchasing inclinations and preferences. KEYWORDS Low variety, high variety, marketing, code choice, psychology, language variation","PeriodicalId":39024,"journal":{"name":"Scientific Journal of King Faisal University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72792536","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}
This study aims to practically identify the reality of empowering Saudi women in leadership positions in higher education institutions, reveal the challenges that prevent their empowerment, and suggest some methods to overcome these challenges. To achieve the study’s objectives, the researcher used the descriptive survey method based on a questionnaire as a tool for the analysis. The researcher used a classified random sample of 376 faculty members in the following Saudi government universities: King Saud in Riyadh, King Abdulaziz in Jeddah, and Imam Abdulrahman bin Faisal in the Eastern. The study reached several conclusions. The analysis indicates that there is empowerment of Saudi women in leadership positions in higher education institutions and that there is agreement among the study sample members on the challenges that prevent the empowerment of Saudi women in leadership positions in higher education institutions. Cultural challenges come first, followed by personal challenges, and finally, organizational challenges. There is strong agreement on ways to overcome challenges that prevent Saudi women from being empowered in leadership positions in higher education institutions. KEYWORDS Saudi universities, change, educational administration, leadership, equality, female
{"title":"Empowering Women in University Leadership Positions: The Saudi Context","authors":"Leena S. Alkhlewi","doi":"10.37575/h/edu/220010","DOIUrl":"https://doi.org/10.37575/h/edu/220010","url":null,"abstract":"This study aims to practically identify the reality of empowering Saudi women in leadership positions in higher education institutions, reveal the challenges that prevent their empowerment, and suggest some methods to overcome these challenges. To achieve the study’s objectives, the researcher used the descriptive survey method based on a questionnaire as a tool for the analysis. The researcher used a classified random sample of 376 faculty members in the following Saudi government universities: King Saud in Riyadh, King Abdulaziz in Jeddah, and Imam Abdulrahman bin Faisal in the Eastern. The study reached several conclusions. The analysis indicates that there is empowerment of Saudi women in leadership positions in higher education institutions and that there is agreement among the study sample members on the challenges that prevent the empowerment of Saudi women in leadership positions in higher education institutions. Cultural challenges come first, followed by personal challenges, and finally, organizational challenges. There is strong agreement on ways to overcome challenges that prevent Saudi women from being empowered in leadership positions in higher education institutions. KEYWORDS Saudi universities, change, educational administration, leadership, equality, female","PeriodicalId":39024,"journal":{"name":"Scientific Journal of King Faisal University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74370150","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}
Soil degradation associated with wind and water erosion and physical and chemical deterioration is increasing at an alarming rate worldwide. This research identified soil characteristics and spatial distribution of soil degradation risks in the Al Ahsa Oasis. Several quantitative analytical approaches used geospatial techniques, namely, ArcGIS, Erdas Imagine10, and ENVI 5.3. Six selected remote sensing indices were used, i.e. the salinity index (SI), normalised difference salinity index (NDSI), brightness index (BI), normalised differential vegetation index (NDVI), vegetation soil salinity index (VSSI), and soil adjusted vegetation index (SAVI) software. Field verification monitored the degradation of different types of soil. Samples were collected in May 2019 and processed using satellite images and mechanical and chemical laboratory analysis for 36 samples. The Universal Soil Loss Equation and climatic data were used to measure the annual soil loss rate in the Al Ahsa Oasis. Integration of these datasets resulted in a map of soil degradation values. The results show that the sampled oasis soils have degraded physically, chemically, and biologically. The average physical degradation was 9.93 g/cm3/year, the average biological degradation was 2.93%/year, and the average chemical degradation was 36.36 mmhos/cm.
{"title":"Determination of Soil Characteristics and Degradation Using Geospatial Technologies in the Al Ahsa Oasis","authors":"Amani Hassan","doi":"10.37575/b/agr/210070","DOIUrl":"https://doi.org/10.37575/b/agr/210070","url":null,"abstract":"Soil degradation associated with wind and water erosion and physical and chemical deterioration is increasing at an alarming rate worldwide. This research identified soil characteristics and spatial distribution of soil degradation risks in the Al Ahsa Oasis. Several quantitative analytical approaches used geospatial techniques, namely, ArcGIS, Erdas Imagine10, and ENVI 5.3. Six selected remote sensing indices were used, i.e. the salinity index (SI), normalised difference salinity index (NDSI), brightness index (BI), normalised differential vegetation index (NDVI), vegetation soil salinity index (VSSI), and soil adjusted vegetation index (SAVI) software. Field verification monitored the degradation of different types of soil. Samples were collected in May 2019 and processed using satellite images and mechanical and chemical laboratory analysis for 36 samples. The Universal Soil Loss Equation and climatic data were used to measure the annual soil loss rate in the Al Ahsa Oasis. Integration of these datasets resulted in a map of soil degradation values. The results show that the sampled oasis soils have degraded physically, chemically, and biologically. The average physical degradation was 9.93 g/cm3/year, the average biological degradation was 2.93%/year, and the average chemical degradation was 36.36 mmhos/cm.","PeriodicalId":39024,"journal":{"name":"Scientific Journal of King Faisal University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69891008","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}
This paper investigates the effect of coral reef roughness on mitigating marine floods by using numerical analysis. The study includes two ocean bathymetries – idealised bathymetry with 1% gradient and real bathymetry – for Gold Coast, Australia. The results indicate that characteristics of the marine flood (wave height and period), coral roughness, and shape of the bathymetry are key to the mitigation of marine floods. Wave height reduction behind the reef and at the shore increases with the incident wave height of the marine flood. The maximum reduction behind the reef is around 60% for both bathymetries for the incident wave height of 4 m. When the incident wave period increases from 10 min to 20 min, the wave height reduction increases to 60% but increases from 20 min to 40 min, decreasing the reduction to as little as 3% behind the reef for the ideal bed condition. However, the marine floods caused by longer period waves can be slowed by higher coral roughness compared to the floods caused by relatively shorter period waves. The wave force reduction behind the reef increases with the incident wave height of the marine flood. The wave force reduction is greater than the wave height reduction behind the reef. KEYWORDS Marine flood; roughness; coral; numerical modelling; long-period waves
{"title":"Coral Mitigates High-energy Marine Floods: Numerical Analysis on Flow–Coral Interaction","authors":"N. Nandasena, Irshaad Chawdhary","doi":"10.37575/b/sci/220007","DOIUrl":"https://doi.org/10.37575/b/sci/220007","url":null,"abstract":"This paper investigates the effect of coral reef roughness on mitigating marine floods by using numerical analysis. The study includes two ocean bathymetries – idealised bathymetry with 1% gradient and real bathymetry – for Gold Coast, Australia. The results indicate that characteristics of the marine flood (wave height and period), coral roughness, and shape of the bathymetry are key to the mitigation of marine floods. Wave height reduction behind the reef and at the shore increases with the incident wave height of the marine flood. The maximum reduction behind the reef is around 60% for both bathymetries for the incident wave height of 4 m. When the incident wave period increases from 10 min to 20 min, the wave height reduction increases to 60% but increases from 20 min to 40 min, decreasing the reduction to as little as 3% behind the reef for the ideal bed condition. However, the marine floods caused by longer period waves can be slowed by higher coral roughness compared to the floods caused by relatively shorter period waves. The wave force reduction behind the reef increases with the incident wave height of the marine flood. The wave force reduction is greater than the wave height reduction behind the reef. KEYWORDS Marine flood; roughness; coral; numerical modelling; long-period waves","PeriodicalId":39024,"journal":{"name":"Scientific Journal of King Faisal University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69894742","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}
The practice of writing in a foreign language is a demanding skill that requires deep understanding of relevant error types. This research focuses on understanding, analysing and specifying the error types related to writing in a foreign language in two different language settings, considering differences in their cultural and linguistic systems. The study has adopted two rubrics for marking and determining different types of error made by learners while writing in a foreign language (English or Arabic). Each rubric, with its error categories, is suitable for the nature of each language. The results of this study can lead to an understanding of major errors in English and Arabic writing experienced by foreign-language learners (e.g., mechanical errors in English and grammatical errors in Arabic). In light of these findings, future learners in academic writing classes of English and Arabic as foreign languages can be provided with further instruction on and exposure to common errors, as well as how to minimize them. Further research is recommended to explore both the benefits of providing sufficient feedback on learners’ future writing and how typical errors are made. KEYWORDS Error, writing, English as a foreign language (EFL), Arabic as a foreign language (AFL), virtual exchange, telecollaboration
{"title":"Learners’ Writing Errors in Foreign Languages: Arabic and English as Examples","authors":"Ahmed A. Al Khateeb","doi":"10.37575/h/lng/220016","DOIUrl":"https://doi.org/10.37575/h/lng/220016","url":null,"abstract":"The practice of writing in a foreign language is a demanding skill that requires deep understanding of relevant error types. This research focuses on understanding, analysing and specifying the error types related to writing in a foreign language in two different language settings, considering differences in their cultural and linguistic systems. The study has adopted two rubrics for marking and determining different types of error made by learners while writing in a foreign language (English or Arabic). Each rubric, with its error categories, is suitable for the nature of each language. The results of this study can lead to an understanding of major errors in English and Arabic writing experienced by foreign-language learners (e.g., mechanical errors in English and grammatical errors in Arabic). In light of these findings, future learners in academic writing classes of English and Arabic as foreign languages can be provided with further instruction on and exposure to common errors, as well as how to minimize them. Further research is recommended to explore both the benefits of providing sufficient feedback on learners’ future writing and how typical errors are made. KEYWORDS Error, writing, English as a foreign language (EFL), Arabic as a foreign language (AFL), virtual exchange, telecollaboration","PeriodicalId":39024,"journal":{"name":"Scientific Journal of King Faisal University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91000009","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}
In the field of water resource management, rainfall intensity-duration-frequency (IDF) curves are of great importance, especially in the design of hydraulic structures and the assessment of flash-flood risks. The aim of this study is to obtain IDF curves and find empirical equations for rain duration for Al-Najaf city in the southwest of Iraq. Rainfall data for 30 years, from 1989 to 2018, were collected. The practical reduction equation of the Indian Meteorological Department (IMD), with six methods of probability distribution, was used for short intervals (0.25, 0.5, 1, 2, 3, 6, 12, and 24 hours) with a specified recurrence period (100, 50, 25, 10, 5, and 2 years). The Kolmogorov-Smirnov, chi-squared, and Anderson-Darling goodness of fit tests were used with the help of EasyFit 5.6 software. The findings revealed that the highest intensity of rainfall occurs during a repeated cycle of 100 years with a duration of 0.25 hours, while the lowest intensity of rainfall occurs during a repeated cycle of 2 years with a duration of 24 hours. In the results obtained from the six methods, as well as the superiority of the log Pearson type III method, the consistency of the fit tests showed some convergence.
{"title":"Development of a General Equation for Intensity-Duration-Frequency (IDF): Iraq","authors":"H. Mahdi","doi":"10.37575/b/eng/0042","DOIUrl":"https://doi.org/10.37575/b/eng/0042","url":null,"abstract":"In the field of water resource management, rainfall intensity-duration-frequency (IDF) curves are of great importance, especially in the design of hydraulic structures and the assessment of flash-flood risks. The aim of this study is to obtain IDF curves and find empirical equations for rain duration for Al-Najaf city in the southwest of Iraq. Rainfall data for 30 years, from 1989 to 2018, were collected. The practical reduction equation of the Indian Meteorological Department (IMD), with six methods of probability distribution, was used for short intervals (0.25, 0.5, 1, 2, 3, 6, 12, and 24 hours) with a specified recurrence period (100, 50, 25, 10, 5, and 2 years). The Kolmogorov-Smirnov, chi-squared, and Anderson-Darling goodness of fit tests were used with the help of EasyFit 5.6 software. The findings revealed that the highest intensity of rainfall occurs during a repeated cycle of 100 years with a duration of 0.25 hours, while the lowest intensity of rainfall occurs during a repeated cycle of 2 years with a duration of 24 hours. In the results obtained from the six methods, as well as the superiority of the log Pearson type III method, the consistency of the fit tests showed some convergence.","PeriodicalId":39024,"journal":{"name":"Scientific Journal of King Faisal University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69892242","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}
In this paper, graphene plasma was obtained through the interaction of the fundamental radiation from a pulsed Nd:YAG laser at the fundamental wavelength of 1064 nm focused onto a solid plane of graphene material. This reaction was carried out under conditions of an atmospheric status. The resulting plasma was tested using an optical emission spectroscopy technique. The temperature of the electrons is calculated by the tow line ratio of C I and C II emission lines singly ionised, and the density of the plasma electron is calculated with Saha-Boltzmann equation. The upper limit of the electron temperature was approximately 1.544 eV. The corresponding electron density was 11.5×1015 cm-3. Then the electron temperature decreased when the energy was 300 mJ and it was near 1.462 eV, corresponding to the density of those electrons 8.7×1015 cm-3.
{"title":"Spectroscopic Investigation of Laser-Induced Graphene Plasma","authors":"M. Khalaf","doi":"10.37575/B/SCI/0053","DOIUrl":"https://doi.org/10.37575/B/SCI/0053","url":null,"abstract":"In this paper, graphene plasma was obtained through the interaction of the fundamental radiation from a pulsed Nd:YAG laser at the fundamental wavelength of 1064 nm focused onto a solid plane of graphene material. This reaction was carried out under conditions of an atmospheric status. The resulting plasma was tested using an optical emission spectroscopy technique. The temperature of the electrons is calculated by the tow line ratio of C I and C II emission lines singly ionised, and the density of the plasma electron is calculated with Saha-Boltzmann equation. The upper limit of the electron temperature was approximately 1.544 eV. The corresponding electron density was 11.5×1015 cm-3. Then the electron temperature decreased when the energy was 300 mJ and it was near 1.462 eV, corresponding to the density of those electrons 8.7×1015 cm-3.","PeriodicalId":39024,"journal":{"name":"Scientific Journal of King Faisal University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69893690","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}
Esraa Mouhson, Sufian H. Humeedi, S. Darweesh, Adnan Ahmed
A plasma thermal spraying method was used for the purpose of coating the pre-prepared surfaces of turbine blades. Chromium oxide (Cr2O3) was used as a matrix reinforced with a metal material of Ni-5%Al at rates of 10, 20, 30, 40 and 50. The cermet powders were stirred for one hour then used to coat bases of steel (316L). A spray distance of 8cm was applied, and the binding material of Ni-22%Cr-10%Al-1%Y was sprayed with a thickness of 100μm. Then, the reinforced matrix was sprayed with a thickness of 300–350μm and the final thickness of the samples prepared was 400–450μm. The samples produced were sintered at 900°C for an hour and a half and underwent a hardness test, which gave the best hardness of the samples after sintering at a reinforcement rate of 50% by 612Hv. The lowest porosity value for the above rate was obtained at 3.88%. The results of the adhesive strength gave a value of 31.5 MPa after sintering and at the same 50% reinforcement. The results of the scanning electron microscope (SEM) showed that there was weakness and cracking in the coating layers at the low reinforcement ratios. However, the mechanical and physical properties improved with the increase in reinforcement ratios to reach the highest value of 50%. KEYWORDS Adhesion force, ceramites, scanning electron microscope, Vickers hardness
{"title":"Treatment of Turbine Blades via Cr2O3-Ni5%Al System Using Plasma Thermal Spraying","authors":"Esraa Mouhson, Sufian H. Humeedi, S. Darweesh, Adnan Ahmed","doi":"10.37575/b/sci/210036","DOIUrl":"https://doi.org/10.37575/b/sci/210036","url":null,"abstract":"A plasma thermal spraying method was used for the purpose of coating the pre-prepared surfaces of turbine blades. Chromium oxide (Cr2O3) was used as a matrix reinforced with a metal material of Ni-5%Al at rates of 10, 20, 30, 40 and 50. The cermet powders were stirred for one hour then used to coat bases of steel (316L). A spray distance of 8cm was applied, and the binding material of Ni-22%Cr-10%Al-1%Y was sprayed with a thickness of 100μm. Then, the reinforced matrix was sprayed with a thickness of 300–350μm and the final thickness of the samples prepared was 400–450μm. The samples produced were sintered at 900°C for an hour and a half and underwent a hardness test, which gave the best hardness of the samples after sintering at a reinforcement rate of 50% by 612Hv. The lowest porosity value for the above rate was obtained at 3.88%. The results of the adhesive strength gave a value of 31.5 MPa after sintering and at the same 50% reinforcement. The results of the scanning electron microscope (SEM) showed that there was weakness and cracking in the coating layers at the low reinforcement ratios. However, the mechanical and physical properties improved with the increase in reinforcement ratios to reach the highest value of 50%. KEYWORDS Adhesion force, ceramites, scanning electron microscope, Vickers hardness","PeriodicalId":39024,"journal":{"name":"Scientific Journal of King Faisal University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69894711","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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