Showing 6 results for Pourahmadi
Volume 12, Issue 2 (4-2023)
Abstract
Abstract
In the present study, The effect of phthalate ester toxicity (0.1 and 1 mg/L) was investigated on some non-specific mucus parameters of common carp (Cyprinus carpio). 180 common carp (17.60±2.22gr) is gathered from warm water fish center and they were allocated into 9 tanks (20 Fish per tank). Fish adapted to new condition for a week. During this time; they were feed twice a day with same diets. Fishes were exposed at 3 concentration treatments containing 0; 0.1 and 1 mg/L DEHP under laboratory condition (25±0.5°C; pH: 7.4-8) for a period of 96 hours. Alkaline phosphatase, lysozyme, soluble protein, and immunoglobulin of mucus was measured and evaluated. The results showed that the levels of lysozyme, alkaline phosphatase and immunoglobulin in common carp skin mucus decreased when exposed to DEHP (with increasing concentration and exposure duration) And the level of soluble protein of common carp skin mucus increased when exposed to DEHP (with increasing concentration and exposure duration). These results indicated that concentrations of DEHP beneficially affects Amino Acid profiles of skin mucus in carp and they were categorized in 4 branches. There were Significant differences between exposed and control groups. Therefore; fish skin mucus can be a biomarker for showing contaminants and toxins. And the high consumption of plastic materials can be a warning to the health of aquatic animals and humans.
S.a.a. Pourahmadi, Sh. Talebi,
Volume 20, Issue 1 (January 2020)
Abstract
Electrowinning is the process of copper deposing from the intracellular electrolyte solution to the cathode by creating an electric current. In the present study, the hydrodynamic simulation of the electrowinning cell of Miduk Copper Complex is studied using computational fluid dynamics. Ansys-CFX software is used for this modeling. Navier Stokes and continuity equations are considered as the two-phase fluid and gas, turbulent, incompressible and steady states and the equation for copper concentration in the electrolyte will be solved with consideration of its specific boundary condition. Turbulence will be modeled using the k-ω method. The general and local simulations have been used together due to the large variation in the properties, close to the cathode and anode, and the large volume of the cell, to create a good mesh and increase the speed and accuracy of the solution. First, in general simulation, the entire geometry of the cell is modeled by creating a suitable mesh. Then in the local simulation, only the volume between the two cathodes of the cell is considered and modeled with higher precision. Data on boundary conditions in the local simulation of interface boundary are obtained with general simulation data, which increases the accuracy of modeling. Comparison of the results of general and local simulations shows an accuracy of up to 30% in close to the electrodes. The results of this simulation are the velocity vector, the concentration of acid and copper, the turbulence intensity, pressure and the volume fraction of the oxygen phase in the whole of the electrowinning cell. Finally, the model has been validated by experiments on the real cells. The results show the high accuracy of this modeling technique with less than 2.5% deviation.
Saeed Pourahmadian, Mohamad Ali Bijarchi,
Volume 24, Issue 7 (July 2024)
Abstract
The compound droplets resulting from water-in-oil-in-water emulsions have many applications, including in the food, pharmaceutical and cosmetic industries. Investigating the effective parameters in the production of these droplets plays an important role in their controlled production. In this numerical study, the production of compound droplets in a three-phase axisymmetric glass capillary microfluidic device is investigated. The structure of this system consists of two co-flow and one flow-focusing devices. In this study, the volume of fluid (VOF) method is used to solve the governing equations in different phases. 5 dimensionless parameters are selected to check the effect of each component on the diameter, the generation frequency, and the breakup length of the compound droplets. This study has successfully predicted the formation of compound droplets in the droplet regime. The simulation results show that with increasing the ratio of inner nozzle diameter to outer tube diameter, the core diameter enhances and the shell thickness decreases. By decreasing the angle of the inner nozzle tip, the drop regime changes to the jet regime. By increasing the contact angle of the middle phase with respect to the outer phase in the outer tube wall from 90 to 120 degrees, the frequency of droplet generation increases by 22%. The results of this study can be used for applications such as 3D cell culture.
Volume 26, Issue 4 (Fall 2023)
Abstract
Background: Most digital imaging systems provide a variety of image processing techniques. The aim of the present study was to compare the performance of bite wing digital radiography with and without the application of 3D emboss image processing filters in identifying recurrent proximal caries. Materials and methods: In the current study, cavities were created in both proximal surfaces of 52 healthy premolar teeth for Class II amalgam restoration. Caries lesions were artificially created by a 0.5 mm trend burr randomly in each tooth and repaired with amalgam. Standard digital radiographs were performed using the Digora® Optime system. Unfiltered and filtered images with 3D emboss filter were observed by 2 radiologists with at least 2 years of work experience and the final results were analyzed with Chi-square statistics. Results: The obtained results demonstrated that the sensitivity and specificity of caries detection changes with the change in the observer, although no significant difference was observed between the sensitivity and specificity of the third and fourth observers. In addition, the results of this research showed that the sensitivity, accuracy and specificity of detecting recurrent secondary caries in radiographs without using the 3D emboss filter for all observers participating in this project was more significant than the sensitivity, accuracy and specificity of radiographs with 3D emboss filter. Conclusion: The obtained data documents that use of the 3D emboss filter failed to improve the diagnosis of recurrent secondary caries through reduces the sensitivity, accuracy and specificity of diagnosis.
Volume 27, Issue 2 (Spring 2024)
Abstract
The current article seeks to review the published literature regarding the possible impacts of antioxidant therapy on the management of oral inflammatory conditions. Evidence for this review was systematically collected from reputable scientific databases, focusing on studies published between 2010 and 2024. To ensure a thorough exploration of the topic, broad keywords such as Antioxidants, Oxidative Stress, Inflammation, and Oral Diseases were employed, utilizing both "OR" and "AND" search strategies. The findings from the reviewed literature suggest that antioxidant therapy, whether derived from natural sources or synthesized, demonstrates statistically significant improvements in alleviating oral diseases associated with oxidative stress and inflammation. In conclusion, this review underscores the promise of antioxidant agents in both the prevention and treatment of inflammatory oral diseases, indicating that dietary changes and the intake of antioxidant supplements may be beneficial in managing these conditions
Volume 28, Issue 1 (Winter 2025)
Abstract
Background: Oral health issues, such as dental caries, periodontal disease, and oral cancer, represent significant challenges to global health. Proper and balanced nutrition plays a vital role in this context, as it is fundamental to overall health, which includes the condition of the oral cavity and teeth. Nutrition pertains to the specific nutrients absorbed by the body, while diet encompasses all nutrients and non-nutrients consumed. The quality of nutrition directly influences the growth, development, and metabolic functions of the periodontium. A deficiency in essential nutrients can lead to changes in the primary factors associated with periodontal diseases, and dietary choices can significantly influence the progression of these ailments. This review article provides a meta-analysis of the existing literature to evaluate the effects of dietary and lifestyle factors on the prevention of oral health problems. Method: A systematic review of studies was performed from databases such as PubMed, Scopus, Web of Science, and the Cochrane Library from 2000 onward to investigate the connections between specific dietary components, lifestyle habits, and oral health outcomes. Results: The findings indicate notable correlations among elevated consumption of processed sugars, inadequate oral hygiene, and the use of tobacco and alcohol, all of which increase the likelihood of developing oral diseases. Conversely, a diet abundant in fruits, vegetables, and vital nutrients, along with consistent oral hygiene practices, is linked to a lower risk of these health issues. Conclusion: This meta-analysis highlights the essential role that dietary and lifestyle modifications play in strategies aimed at preventing oral diseases
