Mehran Masdari, Maryam Ghorbani and Arshia Tabrizian
The purpose of this paper is to analyze experimentally subsonic wake of a supercritical airfoil undergoing a pitch–hold–return motion. The focus of the investigation has been…
Abstract
Purpose
The purpose of this paper is to analyze experimentally subsonic wake of a supercritical airfoil undergoing a pitch–hold–return motion. The focus of the investigation has been narrowed to concentrate on the steadiness of the flow field in the wake of the airfoil and the role of reduced frequency, amplitude and the hold phase duration.
Design/methodology/approach
All experiments were conducted in a low sub-sonic closed-circuit wind tunnel, at a Reynolds number of approximately 600,000. The model was a supercritical airfoil having 10% thickness and wall-to-wall in ground test facilities. To calculate the velocity distribution in the wake of the airfoil, total and static pressures were recorded at a distance of one chord far from the trailing edge, using pressure devices. The reduced frequency was set at 0.012, 0.03 and the motion pivot was selected at c/4.
Findings
Analysis of the steadiness of the wake flow field ascertains that an increase in reduced frequency leads to further flow time lag in the hold phase whereas decreases the time that the wake remains steady after the start of the return portion. Also, the roles of amplitude and stall condition are examined.
Practical implications
Examination of a pitch–hold–return motion is substantial in assessment of aerodynamics of maneuvers with a rapid increase in angle of attack. Moreover, study of aerodynamic behavior of downstream flow field and its steadiness in the wake of the airfoil is vital in drag reduction and control of flapping wings, dynamic stability and control of aircrafts.
Originality/value
In the present study, to discuss the steadiness of the flow field behind the airfoil some statistical methods and concept of histogram using an automatic algorithm were used and a specific criterion to characterize the steadiness of flow field was achieved.
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Maryam Nilghaz, Mohammadreza Shahparvari, Azita Hekmatdoost, Saeede Saadati, Moloud Ghorbani, Amir Sadeghi and Zahra Yari
Dietary components have been mentioned as modifiable risk factors in the development of gallstone disease (GSD), but it has been less addressed. The present study aimed to…
Abstract
Purpose
Dietary components have been mentioned as modifiable risk factors in the development of gallstone disease (GSD), but it has been less addressed. The present study aimed to investigate the potential association between different types of dietary carbohydrate and the risk of gallstone.
Design/methodology/approach
In this case-control study 189 patients diagnosed with GSD as a case group and 342 people as a control group were enrolled. Dietary intake of the participants was collected through a 168-item semi-quantitative food frequency questionnaire. Total intakes of calories, macronutrients and different types of carbohydrate were estimated. Crude and multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the association between carbohydrate intake and GSD.
Findings
Patients with gallstone consumed significantly more fructose and sucrose and less fiber. After fully adjustment, the logistic regression indicated significant association between GSD with dietary intake of total carbohydrate (OR = 1.65, 95% CI: 1.1–2.4, p = 0.009), sugar (OR = 1.23, 95% CI: 0.8–1.7, p = 0.014), fructose (OR = 2.5, 95% CI: 1.7–3.9, p < 0.001), glucose (OR = 1.9, 95% CI: 1.3–2.9, p = 0.002) and sucrose (OR = 1.37, 95% CI: 0.9–1.6, p = 0.042). Also, increasing intakes of lactose, galactose and maltose were associated with a decrease in the risk of GSD, but not statistically significant, although lactose was close to significance (OR = 0.71, 95% CI: 0.48–1, p = 0.051).
Originality/value
There is a positive and significant relationship between total carbohydrate, sugar, fructose, glucose and sucrose intake and the occurrence of gallstone.
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Pedram Pam, Maryam Behrooz, Mehrdad Jamali, Hosna Ghorbani, Amirataollah Hiradfar, Azim Rezamand and Zohreh Ghoreishi
The purpose of this study is to investigate the relationship between dietary total antioxidant capacity (DTAC) and the dietary inflammatory index (DII) with inflammatory status in…
Abstract
Purpose
The purpose of this study is to investigate the relationship between dietary total antioxidant capacity (DTAC) and the dietary inflammatory index (DII) with inflammatory status in children recently diagnosed with Acute Lymphoblastic Leukemia (ALL). As the relationship between diet quality scores and inflammation remains uncertain in this population, the authors carried out a hospital-based cross-sectional study.
Design/methodology/approach
The study used a cross-sectional design involving 54 children recently diagnosed with ALL. Dietary data was collected using a 147-item semi-quantitative food frequency questionnaire developed for the Tehran Lipid and Glucose Study. Inflammatory status was evaluated using various indicators like C-reactive protein (CRP), neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), Glasgow prognostic score (GPS) and Complete blood count-based inflammatory score.
Findings
The authors found no significant relationship between DII with inflammatory indices and length of hospitalization in patients. However, a significant inverse relationship was observed between the antioxidant indices ferric-reducing ability of plasma, total reactive antioxidant potential and Trolox equivalent antioxidant capacity with the inflammatory index MLR, respectively (ß: −0.19, p = 0.001), (ß: −0.42, p = 0.02), (ß: −0.53, p = 0.005). Also, a significant inverse relationship between FRAP and CRP was observed in the crude model (ß: −0.13, p = 0.05). FRAP was also inversely correlated with GPS and PLR, respectively (ß: −0.08, p = 0.02), (ß: −0.26, p = 0.03). No additional significant links were discovered between food scores and the outcomes studied.
Originality/value
This study found no link between DII with inflammatory markers or hospitalization duration in children with ALL. However, the authors did observe a noteworthy inverse relationship between DTAC and certain inflammatory markers like MLR. To achieve more dependable findings, further research in this area is necessary.
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Satar Rezaei, Behzad Karami Matin, Mohammad Hajizadeh, Ali Soroush, Zahra Mohammadi, Maryam Babakhany and Khadije Jamshidi
Education is a human right and access to high quality education is key to sustainable socioeconomic development. Improving the quality of higher education institutes is essential…
Abstract
Purpose
Education is a human right and access to high quality education is key to sustainable socioeconomic development. Improving the quality of higher education institutes is essential for generating the productive human resources. Assessing the quality of higher education from the students’ perspective can be considered a crucial factor in the monitoring of service quality in universities. The purpose of this paper is to evaluate the quality of educational services in a higher education institute, the Kermanshah University of Medical Sciences (KUMS), in the west of Iran.
Design/methodology/approach
A multistage sampling method was used to select 346 students from the KUMS, who were enrolled in the second semester of the academic year 2015-2016. The SERVQUAL questionnaire was used to gather data on students’ perceptions and their expectations about the quality of educational services. The authors used a statistical significance level of 0.05 to examine the gap between the students’ expectations and their perceptions of service quality in five dimensions, namely tangibles, responsiveness, reliability, empathy and assurance.
Findings
The results showed that there was a negative service quality gap in all five dimensions. The overall mean score of students’ expectations and their perceptions was 3.19±0.44 and 2.4±0.45, respectively. The score gap between the overall mean score of perceptions and expectations of students was −0.79, which was statistically significant (p<0.0001). The highest and lowest quality gaps were related to the assurance (−0.84) and tangible (−0.70) dimensions, respectively.
Originality/value
The study indicated that the quality of educational services provided in the KUMS did not meet students’ expectations in five dimensions of service quality. Thus, it warrants further investigations to determine how to improve the quality of educational services in higher education institutes such as the KUMS.
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Maryam Seifzadeh, Raha Rajaeei and Arezao Allahbakhsh
This study aims to assess the relationship between managerial entrenchment and the chance of fraud in financial statements, which are the only available source for shareholders’…
Abstract
Purpose
This study aims to assess the relationship between managerial entrenchment and the chance of fraud in financial statements, which are the only available source for shareholders’ decisions, so their accuracy and reliability are of great importance. Hence, the realization of contributing factors to preventing financial information distortion is vital. Moreover, managerial entrenchment on the chance of fraud in the company’s upcoming years has also been analyzed.
Design/methodology/approach
The factor analysis of five variables [chief executive officer (CEO) duality, managerial ownership, board independence, board compensation and CEO tenure] is used for management entrenchment. To examine the hypothesis testing, multivariate regressions, feasible general least squares regression and Logit model regression are used. The statistical sample under study in this paper includes 1,122 year-company observations during 2013–2018 and Beneish’s (1999) model is used for evaluating fraud.
Findings
The study results show a negative and significant relationship between management entrenchment and the chance of fraud in financial statements. That means managers with a higher degree of managerial entrenchment are more likely to create value and acquire wealth for the firm, and that causes them not to waste and waste the firm resources through enhancing the supervisory mechanisms. Moreover, the study results also show that improving and strengthening management entrenchment will lower the upcoming years’ fraud condition.
Originality/value
The current paper is the first time that the relationship between managerial entrenchment and financial statement fraud is assessed within a study. The results of the paper help the beneficiaries and shareholders realize different aspects of management entrenchment. That means managers’ power and authority can be used to make shareholders’ interests, but they can hinder misuse and fraud.
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Mohammad Mehdi Mohammadi, Mehdi Safari Gerayli, Maryam Shahri, Hasan Valiyan and Farhad Dehdar
The citizen-shareholder approach in the capital market is considered a knowledge-enhancing and emerging concept in financial and accounting offerings. Its reliable background in…
Abstract
Purpose
The citizen-shareholder approach in the capital market is considered a knowledge-enhancing and emerging concept in financial and accounting offerings. Its reliable background in management and human sciences makes it an essential basis for protecting the interests of shareholders and investors. Shareholders are considered a necessary part of the social platforms that are companies and regulatory institutions in the capital market; beyond being obligated to protect their material and intellectual rights, they are responsible for developing norms and facilitating investment values and gaining trust through mutual interactions based on respect for their interests. The purpose of this paper is to perform interactive qualitative analysis of the requirements for protecting the rights of citizens of capital market shareholders.
Design/methodology/approach
The methodology of the research is mixed, so that in the qualitative part, through content screening, the dimensions related to the protection of the citizen rights of the capital market shareholders were identified through a systematic review of 10 research in the period of 2017–2022. Then, the reliability of the specified dimensions was examined through Delphi analysis; in the quantitative part of the research, the criteria identified through the pairwise comparison matrix were first determined by the level of their relationships to determine based on the pattern of systemic representation of drivers and the consequences of requirements to protect the rights of citizens of capital market shareholders.
Findings
The research results in the qualitative part indicated the existence of 12 primary themes; during the two stages of Delphi analysis, three themes were removed, and a total of nine themes entered the quantitative phase. The results in a quantitative part indicate the creation of specialized and active committees of the board of directors as the primary driver and the reliability and timely disclosure of information in the long term as a systemic consequence.
Originality/value
To the best of the authors’ knowledge, this is the first research that presents the new concept of citizen shareholders to strengthen the requirements of protecting the rights of shareholders in the capital market while developing new theoretical literature.
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Maryam Hemmati, Saleh S. Tabrizy and Yashar Tarverdi
To study the key determinants of chronically high inflation in Iran.
Abstract
Purpose
To study the key determinants of chronically high inflation in Iran.
Design/methodology/approach
Relying on annual data from 1978 to 2019, the authors employ an Auto-Regressive Distributed Lag (ARDL) model and Error Correction Model (ECM) to study the inflationary effects of monetary and fiscal policies as well as exchange rate swings and sanctions intensification.
Findings
The authors find that increase in money supply, depreciation of nominal exchange rate, increase in fiscal deficit and intensification of sanctions are among the key drivers of inflation in Iran. Their impact is profound in the long run, but in the short run only money supply and currency depreciation are significant. Also, when exploring the inflation in different components of Consumer Price Index (CPI), we find robust long- and short-run effects from money supply and exchange rate, while the effects of fiscal deficit and sanctions vary across different components.
Originality/value
The authors contribute to the literature by setting apart the long-vs short-run effects of key variables on inflation in Iran. The authors also employ improved measures of fiscal deficit and sanctions that are shown to be of significance in the long run. Lastly, the authors go beyond the aggregate index and examine the variations in different CPI components.
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Maryam Fatima, Ayesha Sohail, Youming Lei, Sadiq M. Sait and R. Ellahi
Enzymes play a pivotal role in orchestrating essential biochemical processes and influencing various cellular activities in tissue. This paper aims to provide the process of…
Abstract
Purpose
Enzymes play a pivotal role in orchestrating essential biochemical processes and influencing various cellular activities in tissue. This paper aims to provide the process of enzyme diffusion within the tissue matrix and enhance the nano system performance by means of the effectiveness of enzymatic functions. The diffusion phenomena are also documented, providing chemical insights into the complex processes governing enzyme movement.
Design/methodology/approach
A computational analysis is used to develop and simulate an optimal control model using numerical algorithms, systematically regulating enzyme concentrations within the tissue scaffold.
Findings
The accompanying videographic footages offer detailed insights into the dynamic complexity of the system, enriching the reader’s understanding. This comprehensive exploration not only contributes valuable knowledge to the field but also advances computational analysis in tissue engineering and biomimetic systems. The work is linked to biomolecular structures and dynamics, offering a detailed understanding of how these elements influence enzymatic functions, ultimately bridging the gap between theoretical insights and practical implications.
Originality/value
A computational predictive model for nanozyme that describes the reaction diffusion dynamics process with enzyme catalysts is yet not available in existing literature.
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Maryam Sadat Seyedi, Mahmoud Reza Sohrabi, Fereshteh Motiee and Saeid Mortazavinik
The purpose of this paper is to analyze nano zero-valent iron (nZVI)-activated carbon/Nickel (nZVI-AC/Ni) by a novel method. The synthesized adsorbent was used to degrade reactive…
Abstract
Purpose
The purpose of this paper is to analyze nano zero-valent iron (nZVI)-activated carbon/Nickel (nZVI-AC/Ni) by a novel method. The synthesized adsorbent was used to degrade reactive orange 16 (RO 16) azo dye.
Design/methodology/approach
The optimum conditions for the highest removal of RO 16 dye were determined. Characterization of nZVI-AC/Ni was done by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction and energy-dispersive X-ray spectroscopy. The nZVI-AC/Ni were used for the removal of dye RO 16 and the parameters affecting were discussed such as pH, adsorbent dosage, contact time and concentration of dye. To investigate the variables and interaction between them, an analysis of variance test was performed.
Findings
The characterization results show that the synthesis of nZVI-AC/Ni caused no aggregation of nanoparticles. The maximum dye removal efficiency of 99.45% occurred at pH 4, the adsorbent dosage = 0.1 gL-1 and the dye concentration of 10 mgL-1. Among various algorithms of feed-forward backpropagation neural network, Levenberg–Marquardt with mean square error (MSE) = 9.86 × 10–22 in layer = 5 and the number of neurons = 9 was selected as the best algorithm. On the other hand, the MSE of the radial basis function model was 0.2159 indicating the good ability of the model to predict the percentage of dye removal.
Originality/value
There are two main innovations. One is that the novel nZVI-AC/Ni was prepared successfully. The other is that the optimized conditions were obtained for the removal of RO 16 dye from an aqueous solution. Furthermore, to the best of the knowledge, no study has ever investigated the removal of RO 16 by nZVI-AC/Ni produced.
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Maryam Hasanzadeh, Fereshteh Kalantari, Hadi Emamat, Hamid Ghalandari and Hadith Tangestani
Iron deficiency anemia (IDA) is the most common nutritional anemia in the world and a pervasive health problem, especially in developing countries. Children under two years of age…
Abstract
Purpose
Iron deficiency anemia (IDA) is the most common nutritional anemia in the world and a pervasive health problem, especially in developing countries. Children under two years of age are more prone to be affected by IDA. The best strategy to prevent and treat IDA is to use iron supplements. This study aims to examine the factors associated with noncompliance (such as non-utilization or inconsistent usage) of iron drop supplementation among infants between 6 and 24 months old.
Design/methodology/approach
Online databases (PubMed, Scopus and SID) were searched to retrieve relevant articles published from inception up to July 2023. Among the 2,177 articles detected, after removing duplicate and irrelevant titles, 21 cross-sectional studies that met the authors’ inclusion criteria were included. Screening for articles and data extraction were conducted separately by two researchers.
Findings
The findings suggest that some factors related to mothers, such as education, knowledge, attitude and performance; some factors associated with child such as child’s gastrointestinal and dental complications; taste and smell of iron drops; and birth order and gender are the main determinants of adherence to iron supplementation.
Originality/value
It can be proposed that the most significant factors affecting the feeding of iron drops to children under the age of two include: the level of mother’s awareness, socio-economic status of the household and the occurrence of digestive complications following the supplementation. Given these observations, adopting proper policies toward improving the nutritional awareness of mothers and producing iron supplements with minimal side effects seems crucial.