Effects of B-Site Donor Modification on the Crystal Structure and the Electrical Properties of Lead-Free 0.65BiFeO3-0.35BaTiO3 Ceramics

salman,파잘 아카람,김준찬,송태권,김명호,이순일,Rizwan Ahmed Malik,Ali Hussain,김원정,성연수 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.75 No.10

In the present work, lead-free piezoelectric ceramics 0.65Bi1.05Fe1−xTixO3-0.35BaTi1−yNbyO3, where x = y = 0, 0.01, 0.015, 0.02, and 0.025, abbreviated as BFT-BTNb, were successfully synthesized by a solid-state reaction method and an air quenching method. The effects of B-Site donor modifications (Nb5+ and Ti4+) on the crystal structure, the morphology and the electrical properties of the 0.65BF-0.35BT ceramics were studied. X-ray diffraction patterns showed the formation of a pure perovskite structure, without any secondary phases. Scanning electron microscope (SEM) micrographs revealed that the average grain size of the BF-BT ceramics decreased with the addition of B-Site donors. Improvements in the ferroelectric properties (P-E loops) and the electric fieldinduced strain properties (S-E loops) were obtained at the optimum composition of the BFT-BTN ceramics. In addition, the dynamic piezoelectric coefficient (d ∗ 33) was enhanced from 265 pm/V for (BFT-BTNb-0) to 360 pm/V for (BFT-BTNb-1) with high working temperature, Tm = 320 ◦ C.

RETRACTED ARTICLE: Droop Control based Approach for Frequency and Voltage in Hybrid AC/DC Microgrid

Salman Salman,Xin Ai 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.5

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A framework of examining the factors affecting public acceptance of nuclear power plant: Case study in Saudi Arabia

Alzahrani Salman M.,Alwafi Anas M.,Alshehri Salman M. 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.3

The Saudi National Atomic Energy project aims to adopt peaceful nuclear technologies and be part of the country's energy mix. As emerging nuclear energy, it is essential to understand public concerns and acceptability of nuclear energy, as well as the factors influencing acceptance to develop nuclear energy policy and implement nuclear energy programs. The purpose of this study is to analyze the public attitudes and acceptance of nuclear energy among Saudi Arabian citizens by utilizing protection motivation theory and theory of planned behavior. A total of 1,404 participants answered a questionnaire which was distribute by convenience sampling approach. A Structural Equation Modeling framework was constructed and analyzed to understand public behavior toward building the country's first Nuclear Power Plant (NPP). Before analyzing the data, the model was validated. The research concluded that the benefits of nuclear power plants were essential in determining people's acceptance of NPPs. Surprisingly, the effect of the perceived benefits was found higher than the effect of the perceived risks to the acceptance. Furthermore, the public's participation in this study revealed that the NPPs location has a significant impact on their acceptance. Based on the finding, several policy implementations were suggested. Finally, the study's model results would benefit scholars, government agencies, and the business sector in Saudi Arabia and worldwide.

Assessment of Geometrical Features of Internal Flaws with Artificial Neural Network

Salman Lari,Yanjun Qian,Hyock Ju Kwon 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.5

In nondestructive testing (NDT), geometrical features of a flaw embedded in the material such as its location, length, and orientation are critical factors to assess the severity of the flaw and make post-manufacturing decisions to improve the design. In this study, artificial intelligence (AI) based NDT approach was applied to the ultrasonic oscillograms obtained from virtual ultrasonic NDT to estimate geometrical features of a flaw. First, a numerical model of NDT specimen was constructed using acoustic finite element analysis (FEA) to produce the ultrasonic signals. The model was validated by comparing the simulated signals produced from the numerical model with the experimental data from actual NDT tests. Then, 750 numerical models containing flaws with different locations, lengths, and orientation angles were generated by FEA. Next, the oscillograms produced by the models were divided into 3 datasets: 525 for training, 113 for validation, and 112 for testing. Training inputs of the network were parameters extracted from ultrasonic signals by fitting them to sine functions. Lastly, to evaluate the network performance, outputs of the network including flaw’s location, length, and angle were compared with the desired values for all datasets. Deviations of the outputs from desired values were calculated by a regression analysis. Statistical analysis was also performed by measuring root mean square error (RMSE) and efficiency. RMSE in x-location, y-location, length, and angle estimations are 0.09 mm, 0.19 mm, 0.46 mm, and 0.75°, with efficiencies of 0.9229, 0.9466, 0.9140, and 0.9154, respectively for the testing dataset. Results suggest that the proposed AI-based method has the potential to interpret the oscillograms from ultrasonic NDT to estimate geometrical features of flaws embedded in the material.

Condition assessment model for residential road networks

Salman, Alaa,Sodangi, Mahmoud,Omar, Ahmed,Alrifai, Moath Techno-Press 2021 Structural monitoring and maintenance Vol.8 No.4

While the pavement rating system is being utilized for periodic road condition assessment in the Eastern Region municipality of Saudi Arabia, the condition assessment is costly, time-consuming, and not comprehensive as only few parts of the road are randomly selected for the assessment. Thus, this study is aimed at developing a condition assessment model for a specific sample of a residential road network in Dammam City based on an individual road and a road network. The model was developed using the Analytical Hierarchy Process (AHP) according to the defect types and their levels of severity. The defects were arranged according to four categories: structure, construction, environmental, and miscellaneous, which was adopted from sewer condition coding systems. The developed model was validated by municipality experts and was adjudged to be acceptable and more economical compared to results from the Eastern region municipality (Saudi Arabia) model. The outcome of this paper can assist with the allocation of the government's budget for maintenance and capital programs across all Saudi municipalities through maintaining road infrastructure assets at the required level of services.

Alumina joining using magnesium- or calcium-aluminosilicate glass-ceramic filler comprising Si3N4

SALMAN MUHAMMAD,Ryu Sung-Soo,윤당혁 한국세라믹학회 2023 한국세라믹학회지 Vol.60 No.3

Magnesium- and calcium-aluminosilicate (MAS and CAS, respectively) glass-ceramics containing different amounts of Si3N4 (0, 20, 40, and 60 wt.%) were examined as fillers for alumina joining. After applying filler paste onto the alumina base plate via screen-printing, joining was performed at 1500 °C for 1 h at 12 MPa pressure in a N 2 atmosphere. The phase and microstructural evolution in the joint interlayer and the resulting joint strength were analyzed as a function of the Si 3N4 content. Both MAS and CAS fillers with up to 40 wt.% Si 3N4 wetted the alumina surface after melting, while those with 60 wt.% Si 3N4 exhibited incomplete melting. The variation in joint strength was explained by the evolution of phases at the interface and the thermal expansion coeffi cient mismatch between the filler and alumina base plate. The highest joint strength of 317 ± 39 MPa was obtained for the MAS fi ller with 40 wt.% Si 3N4.

Design Structure Matrix: A Model Proposal and Implementation on Harbor and Building Design Project

Salman Akram,김정환,피승우,서종원 한국건설관리학회 2013 한국건설관리학회 논문집 Vol.14 No.1

Design is an iterative, generative, and multidisciplinary process by its nature. Iteration occurs often in most of the engineering design and development projects including construction. Design iterations cause rework, and extra efforts are required to get the optimal sequence and to manage the projects. Contrary to simple design, isolation of the generative iterations in complex design systems is very difficult, but reduction in overall iterations is possible. Design depends upon the information flow within domain and also among various design disciplines and organizations. Therefore, it is suggested that managers should be aware about the crucial iterations causing rework and optimal sequence as well. In this way, managers can handle design parameters related to such iterations proactively. There are a number of techniques to reduce iterations for various kinds of engineering designs. In this paper, parameter based Design Structure Matrix (DSM) is chosen. To create this DSM, a survey was performed and then partitioned using a model. This paper provides an easy approach to those companies involved in or intend to be involved in“ design and build projects.”

An Analysis by Window DEA on the Influence of International Sanction to the Efficiency of Iranian Container Ports

Salman ZARBI,Sang-Hoon SHIN,Yong-John SHIN 한국해운물류학회 2019 The Asian journal of shipping and Logistics Vol.35 No.4

The sanctions imposed on the Iranian port's operators and shipping lines during the period of year 2012 to 2018 were huge challenges for Iranian seaports and maritime trades. Its impact on container business was instantaneous and port throughput shrank by 38 percent. In order to evaluate the Iranian porfs performance and their relative efficiency during the sanction period, 10-year data had been collected for five container ports of Iran. This set of data was then analyzed by using Data Envelopment Analysis (DEA). All ports had shown decreased port average efficiency after imposed sanction. Then four ports namely Khorramshahr (from 0.73 to 0.51), Bushehr (from 0.78 to 0.83), Bandar Imam Khomeni (from 0.27 to 0.33) and Chabahar (slight increase) had shown increased port average efficiency only one port namely Shahid Rajaei (from0.89 to .083).

Numerical Investigation on Shear Deflection of Steel Welded I Sections with Varying Span to Depth Ratios

Salman Kamali,Harry Far 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.2

Defl ection of the steel I-sections is an important phenomenon that needs to be taken into account to ensure that the serviceability limit state criteria of the Australian Standards are met. The method that is widely used to calculate the defl ection of steel I-sections is by the use of existing formulae that only accommodate the bending stiff ness of the beams. A numerical investigation is performed in this study to fi nd the contribution of shear eff ects in the fi nal defl ection of the Welded-Beams (WB) and Welded-Columns (WC). The numerical analyses were carried out in SAP2000 and numerical model was fi rst validated using the experimental results of welded plate girders. The model was then used to analyse simply supported WB and WC sections under uniformly distributed load (UDL) with varying span lengths. The results of the numerical analyses are reported in this study which compare the mid-span defl ection values from the simply supported defl ection formula with the numerical model defl ection values. The data acquired from the numerical analyses were used to establish a span to depth ratio for WB and WC sections below which the shear defl ection becomes signifi cant. The analysis of the results obtained from the numerical investigation suggests that a predication error begins to emerge in the result that is acquired from fl exure defl ection formulae at a certain span-depth ratio.

Public awareness and practices towards health impacts of PM<SUB>2.5</SUB> in the Kingdom of Bahrain: identifying areas for intervention

Salman Alzayani,Maha Alsabbagh 환경독성보건학회 2022 환경독성보건학회지 Vol.37 No.2

Air quality has critical public health impacts as several diseases have been attributed to exposure to high PM<SUB>2.5</SUB> concentrations. In the Kingdom of Bahrain context, while the sources of PM<SUB>2.5</SUB> and prevailing trends have been studied, its social and health dimensions remain a gap in the literature. This study explores public perceptions of PM<SUB>2.5</SUB> in the Kingdom of Bahrain, focusing especially on public awareness of PM<SUB>2.5</SUB>, its sources, and its health impacts. It further highlights actions taken by individuals to mitigate associated health impacts. This cross sectional study was based on the Driver-Pressure-State-Impact-Response framework. A self-administered questionnaire was distributed to the public, a total sample size of 263 responses. Descriptive statistics, including frequencies and percentages of participants’ responses, were calculated. The Independent Samples t-test and a one-way analysis of variance (ANOVA) were applied along with the Chi-Square test to identify factors associated with the public’s knowledge and practices relating to PM<SUB>2.5</SUB> in Bahrain. A p-value of less than 0.05 was considered as statistically significant. A significant proportion of the participants were unaware of PM<SUB>2.5</SUB>, its concentration in Bahrain, and whether it is being measured. However, the majority of respondents had respiratory problems and took self-protective measures when the air quality was bad. There were statistically significant differences in the adoption of precautionary measures, which was prevalent among participants suffering from respiratory problems. Around 32% of the respondents were willing to pay monthly contributions to improve air quality and indicated their interest in receiving information on Bahrain’s air quality via social and mass media. The findings suggest that there is a need to raise public awareness towards air pollution and its health effects. Moreover, epidemiological studies should be conducted to advance understanding on how air pollution is linked to morbidity and mortality in Bahrain.