An integrated of fuzzy-WASPAS and E-FMEA methods for environmental risk assessment: a case study of petrochemical industry, Iran.

Due to the scope and volume of activities, the petrochemical industry has a high potential for risk to humans and the environment. This study aimed to evaluate the environmental risks caused by the ammonia and urea production process. To screen the risks identified in the follow-up phase, the process hazard analysis (PHA) was used. The environmental aspects were also assessed using environmental failure mode and effects analysis (EFMEA). The most significant environmental aspect with a Risk Priority Number (RPN) of 100 was related to CO2 emissions from the disposal tower. To rank the final aspects, the criteria "severity," "probability of occurrence," "probability of detection," and the "extent of contamination" were first weighed by the fuzzy Shannon entropy method. Then, each aspect was prioritized based on the mentioned criteria and using fuzzy Weighted Aggregated Sum Product Assessment (WASPAS). According to this technique, among the 24 environmental aspects, the highest score (with a value of 0.702) was given to CO2 emissions from the disposal tower. Finally, suggestions were made to mitigate the risks.

Comparative analytical study of the results of environmental risk assessment of urban landfills approach: bowtie, network analysis techniques (ANP), TOPSIS (case study: Gilan Province).

Most landfill projects run in a dynamic and complex environment; therefore, uncertainty and risk are inherent. To improve the performance and reduce the damage caused by waste, risk study and its management have become necessary in implementing landfill location projects. As a result of the biodegradation of organic matter in waste, landfills produce various materials such as leachate, and gas. Therefore, it is necessary to conduct environmental risk assessments so that the destructing factors and their effects on the environment can be identified, and subsequently, control and management solutions offered. In the present study, the author has identified the most critical risks of construction phases and operation of landfills in Gilan province, using the Analytic Network Process (ANP), Delphi, and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) techniques. According to the results, the environmental sector represents the highest risk in the construction and operation phases. Therefore, solutions for reducing or eliminating adverse outcomes have been proposed according to the bowtie method. Solutions to reduce or eliminate the adverse effects of leachate leakage from the landfill floor that causes pollution and infiltration into groundwater: installation of a conventional control system. Routing of landfill gases by passing soil filters at the highest points of landfills using the bowtie method is recommended. The results showed that anthropogenic activities related to sanitary landfilling of waste have greatly affected Gilan province in recent years.

Using Artificial Intelligent to Model Predict the Biological Resilience With an Emphasis on Population of cyanobacteria in Jajrood River in The Eastern Tehran, Iran.

Prediction of bio-resilience in water resources such as rivers is important for better management of land-use systems and water resources. This study has proposed the use of artificial intelligent (AI) models for assessing the relationship among the biological conditions in Jajrood River. For this purpose, the qualitative monthly data of the river related to 2008-2018 were applied. Different resilience indicators for preparation of scenarios were determined using the canonical correlation analysis (CCA) method. Appropriate time-series scenarios (5scenarios) were modelled via Gene Expression Programming (GEP) plus Support Vector Machine (SVM), the bio-indicators were predicted. In order to reduce the error, the wavelet hybrids (W-GEP and W-SVM) were also used for modelling. Validation of the models was performed using Nash-Sutcliffe efficiency (E), root mean square error (RMSE), and mean absolute error (MAE). In all the models investigated, Scenario 3 and Scenario 4 had the highest and lowest accuracies as 0.98 and 0.33 in validation, respectively. The third scenario combined with NO3 -, BODt-1, BOD, PO3-, and Q provided the best results. Then, the values of 0.98, 0.94, 0.82, and 0.78 were obtained for its validation by WSVM, WGEP, SVM, and GEP models, respectively. These findings suggested the superiority of hybrid models and SVM over classical models and GEP in water quality assessment respectively. Examination of the scenarios revealed that NO3 - and DO had the highest and the lowest impact on Shannon index of Cyanophyceae algae over time, as a bio-indicator of water quality in the river, respectively.

Effect of low-level diode laser on streptococcus mutans and lactobacillus acidophilus growth: An invitro study.

Introduction: Caries lesions are high prevalent dental infectious. Gram-positive bacteria are the most common pathogenic microorganisms causing caries lesions. Low-Level laser therapy has been shown to have a significant bactericidal effect without causing damage to the oral tissues. This study was designed to evaluate the efficacy of diode laser (980 nm) at different times and doses on Streptococcus (S.) Mutans and (Lactobacillus) L. Acidophilus microorganisms. Methods: This study was performed on two groups of microorganisms, including S. mutans and L. acidophilus, at a concentration of 108 CFU/ml, which exposed to a diode laser source with a central wavelength of 980 nm to investigate three different energies with the following time-exposures (at doses of 5, 10 and 20 J/cm2 with irradiation times of 5, 10 and 20 s). The growth of bacteria (CFU/ml) was calculated. Results: A significant decrease in CFUs/ml of two microorganisms was observed immediately and 24 h after irradiation (p-value < 0.05). The most effective laser radiation for S. mutans immediately and 24 h after exposure was seen at 5 s with 20 J/cm2 and 20 s with 5 J/cm2, respectively. The most effective laser radiation for L. acidophilus was the time of 5 s with 10 J/cm2 both immediately and 24 h after exposure. Conclusion: In the present study, we demonstrated that diode laser (980 nm) has great efficacy in the growth reduction of S. mutans and L. acidophilus at different times and doses.

Ecotourism spatial-time planning model using ecosystem approaches and landscape ecology.

Tourism industry is one of the new fields and new fields studied by various sciences and today it has been considered by countries in various ways. Because the use of tourism potential and capabilities in each region can provide a dynamic and active ground for the development of that region, the study of the potential of these capabilities in terms of geography will be a special necessity. Therefore, the aim of the study was to evaluate and validate a variety of criteria and methods of land capability assessment for tourism and ecotourism. In this study, the aesthetic value of the landscape, the value of the landscape, and the quality of the habitat and the rarity of the habitat effect were studied from 2000 to 2020 and were predicted for 2040. The result of this study showed that the four criteria used in the decision system with fuzzy gamma method will improve the model from 0.42 to 0.776. The 8 most common criteria for reviewing resources by overlapping methods in ecotourism decision-making systems were not accurate enough or could not be referenced for other areas.

An evaluation of the marine environmental resilience to the north of Qeshm Island.

There is always an adamant need to comprehend and draw the complex challenges of sustainability in order to help organize studies, due to the increasing human-related pressures on coastal zones. Hence, by formulating such a comprehensive framework, it could be possible to anticipate changes and support managerial decisions, as well as the degree of resilience of the region's environment. One of the approaches utilized in littoral or coastal zones is the conceptual framework of drivers, pressure, status, impact, and responses (DPSIR)..Qeshm Island, the largest island in the Persian Gulf, is accounted for being the most vital and strategic areas of the mentioned region. In recent decades, Qeshm has become one of the major cultural, natural, geological, and tourism hubs of the country due to its unique regional characteristics, along with its biodiversity and environmental sensitivity. Thereby, in the present research, a combined approach shall be followed to explore the resilience of the marine environment on the northern coast of Qeshm Island by taking advantage of the socioeconomic criterion. In this respect, the conceptual framework of the DPSIR model is utilized in combination with the structural equation model (SEM-PLS) (or partial least squares), which is one of the nonexperimental techniques, to quantify the results in the best manner possible. On the basis of the fuzzy cognitive map (FCM), the regional economic index bearing the weights of 0.62, 0.62, and 0.5, along with an institutional-managerial and biological index, respectively, denotes a two-way positive correlation, whereas this factor has a two-way, but adverse correlation, relationship with a weight of 0.65 in terms of the sociocultural index. Similarly, there is also a one-way and negative relationship, as to the economic index, with a weight of 0.69 which is in relevance with the physio-chemical index.

A comparative study on the stress distribution around dental implants in three arch form models for replacing six implants using finite element analysis.

BACKGROUND: Dental implant is a method to replacement of missing teeth. It is important for replacing the missed anterior teeth. In vitro method is a safe method for evaluation of stress distribution. Finite element analysis as an in vitro method evaluated stress distribution around replacement of six maxillary anterior teeth implants in three models of maxillary arch. MATERIALS AND METHODS: In this in vitro study, using ABAQUS software (Simulia Corporation, Vélizy-Villacoublay, France), implant simulation was performed for reconstruction of six maxillary anterior teeth in three models. Two implants were placed on both sides of the canine tooth region (A model); two implants on both sides of the canine tooth region and another on one side of the central incisor region (B model); and two implants on both sides of the canine tooth region and two implants in the central incisor area (C model). All implants evaluated in three arch forms (tapered, ovoid, and square). Data were analyzed by finite analysis software. RESULTS: Von Mises stress by increasing of implant number was reduced. In a comparison of A model in each maxillary arch, the stress created in the cortical and cancellous bones in the square arch was less than ovoid and tapered arches. The stress created in implants and cortical and cancellous bones in C model was less than A and B models. CONCLUSIONS: The C model (four-implant) reduced the stress distribution in cortical and cancellous bones, but this pattern must be evaluated according to arch form and cost benefit of patients.

Salivary Interferon Gamma and Interleukin-4 Levels in Patients Suffering from Oral Lichen Planus.

OBJECTIVE: Oral lichen planus (OLP) is a chronic inflammatory disease. Immunological factor may act as etiological factor. The cellular immune cells such as T cells are impor- tant in pathogenesis. Interferon gamma (IFN-γ) and interleukin 4 (IL-4) are secreted by T-helper 1 (Th1) and Th2, respectively. The aim of this study was to investigate the cor- relation between salivary levels of IFN-γ and IL-4 with OLP. MATERIALS AND METHODS: This case control study included sixty three Iranian OLP patients who were selected from the Department of Oral Medicine of Ahvaz Jundishapur University of Medical Sciences from January to July 2013. An equal number of healthy volunteers were also selected as a control group. The OLP patients were then divided into two follow- ing sub-groups: reticular (n=30) and erythematous/ulcerative (n=33). All patients had no systemic disease and received no medication. IFN-γ and IL-4 levels in whole unstimulated saliva (WUS) were measured using the enzyme-linked immunosorbent assay (ELISA) test. Data analysis was done using t test, ANOVA, least significant difference (LSD) test, and the Kruskal-Wallis test. RESULTS: Reticular OLP patients showed higher salivary IFN-γ (7.74 ± 0.09 pg/ml ) and IL-4 (3.876 ± 0.05 pg/ml) levels compared with the control group, indicating that difference was significant. Salivary IFN-γ/IL-4 ratio significantly increased compared with control group (P=0.042). Salivary IFN-γ and IL-4 levels between sub-groups (re- ticular and erythematous/ulcerative) were not significantly different (2.6 ± 0.06 and 2.3 ± 0.05, respectively, P<0.05). CONCLUSION: Salivary IFN-γ and IL-4 levels were increased in OLP patients. An increase of salivary IFN-γ/IL-4 ratio in OLP patients showed that Th1 might have a dominant role in the OLP pathogenesis.

Investigation of The Association between Salivary Procalcitonin Concentration and Chronic Periodontitis.

OBJECTIVE: Chronic periodontitis is the most common form of periodontal disease. Chang- es in biomarkers seem to be associated with the disease progression. Procalcitonin (PCT) is one of these biomarkers that are altered during infection. This study was established to investigate the relationship between periodontitis as an infectious disease and salivary PCT. MATERIALS AND METHODS: This case-control study was performed on 30 patients with gen- eralized chronic periodontitis and 30 health individuals as control group who were referred to Dental School, Jundishapur University of Ahvaz, Ahvaz, Iran at Feb to Apr 2014. The saliva samples were collected and analyzed by the enzyme-linked immunosorbent assay (ELISA) method. Data analysis was performed using t test with the SPSS (SPSS Inc., Chicago, IL, USA) version 13. RESULTS: In both groups, age and sex distribution values were not significantly differ- ent. The concentrations of salivary PCT in controls and patients ranged from 0.081 pg/ mL to 0.109 pg/mL and from 0.078 pg/mL to 0.114 pg/mL, respectively. The statistically significant differences between the two groups were not observed (P=0.17). CONCLUSION: It seems that salivary PCT concentration is not affected by disease progres- sion. Therefore, PCT is not a valuable marker for the existence of periodontal disease.

Comparison of the Antibacterial Properties of Three Mouthwashes Containing Chlorhexidine Against Oral Microbial Plaques: An in vitro Study.

BACKGROUND: The mouth provides an environment that allows the colonization and growth of a wide variety of microorganisms, especially bacteria. One of the most effective ways to reduce oral microorganisms is using mouthwashes. OBJECTIVES: The aim of this study was to investigate the antibacterial effects of chlorhexidine mouthwashes (manufacture by Livar, Behsa, Boht) on common oral microorganisms. MATERIALS AND METHODS: In this in vitro study, isolated colonies of four bacteria, including Streptococcus mutans, S. sanguinis, S. salivarius and Lactobacillus casei, were prepared for an antimicrobial mouth rinse test. The tube dilution method was used for determining the minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC). RESULTS: The MICs for Kin gingival, Behsa and Boht mouthwashes were 0.14, 0.48 and 1000 micrograms/mL using the tube method for S. mutans, respectively. The MBCs for the mentioned mouthwashes were 0.23, 1.9 and 2000 micrograms/mL for S. mutans, respectively. The MICs for Kin gingival, Behsa and Boht mouthwashes were 0.073, 0.48 and 250 micrograms/mL using the tube method for S. sanguinis, respectively. The MBCs for the mentioned mouthwashes were 0.14, 1.9 and 1000 micrograms/mL for S. sanguinis, respectively. CONCLUSIONS: The Kin Gingival chlorhexidine mouthwash has a greater effect than Behsa and Boht mouthwashes on oral microorganisms and is recommended to be used for plaque chemical inhibition.

A comparison of magnetostrictive and piezoelectric ultrasonic scaling devices: an in vitro study.

PURPOSE: The effects of magnetostrictive and piezoelectric devices on tooth surfaces seem to differ with regard to the root surface roughness they produce. This study aimed to compare the results of scaling using magnetostrictive and piezoelectric devices on extracted teeth. METHODS: Forty-four human extracted teeth were assigned to four study groups (n=11). In two groups (C100 and C200), the teeth were scaled using a magnetostrictive device and two different lateral forces: 100 g and 200 g, respectively. In the other two groups (P100 and P200), the teeth were scaled with a piezoelectric device with 100 g and 200 g of lateral force, respectively. he teeth were scaled and the data on the duration of scaling and the amount of surface were collected and analyzed using the t-test. RESULTS: The mean time needed for instrumentation for the piezoelectric and magnetostrictive devices was 50:54 and 41:10, respectively, but their difference was not statistically significant (P=0.171). For root surface roughness, we only found a statistically significantly poorer result for the C200 group in comparison to the P200 group (P=0.033). CONCLUSIONS: This study revealed that applying a piezoelectric scaler with 200 g of lateral force leaves smoother surfaces than a magnetostrictive device with the same lateral force.

Comparison of salivary antioxidants in healthy smoking and non-smoking men.

BACKGROUND: Tobacco use is known as a serious global public health problem, and is also an important risk factor for oral diseases. Saliva is the first biological medium encountered during inhalation of cigarette smoke. Therefore, the main aim of this study was to compare the levels of salivary antioxidants between healthy smoking and non-smoking men. METHODS: Unstimulated whole saliva samples were collected from 80 men. Forty subjects were smokers with a daily consumption of 20 cigarettes for at least 10 years and 40 subjects were non-smokers. The salivary levels of uric acid, superoxide dismutase, glutathione peroxidase, and peroxidase were measured and compared between studied groups. RESULTS: The mean levels of salivary superoxide dismutase, glutathione peroxidase, and peroxidase were significantly lower in smokers than non-smokers. There was no statistically significant difference in the salivary uric acid level between smokers and non-smokers. CONCLUSIONS: Measurement of antioxidant agents in human saliva might be useful for estimating the level of oxidative stress caused by cigarette smoke.

Detection of IL-4, IL-6 and IL-12 serum levels in generalized aggressive periodontitis.

BACKGROUND: Periodontitis is a multifactorial chronic inflammatory disease characterized by destruction of tooth-supporting tissues. Environmental and genetic factors as well as the immune system participate in this process. Recent studies have attempted to elucidate the role of cytokine networks involved in periodontal diseases. OBJECTIVE: To assess and compare the levels of IL-4, IL-6 and IL-12 in serum samples of patients with generalized aggressive periodontitis (GAgP) and control individuals. METHODS: A total of 50 subjects were included in the study of which 25 patients had generalized aggressive periodontitis and 25 were healthy unrelated age and gender matched patients undergoing extraction and surgical crown lengthening (control group). Local blood samples of patients were collected from surgical sites of pocket reduction and from healthy individuals before tooth extraction or crown lengthening from non inflamed sites. The levels of IL-4, IL-6 and IL-12 were determined by an ELISA assay using serum samples separated from the whole blood of both groups. RESULTS: The level of IL-4 increased significantly in control group in comparison with the test group (p=0.002). The amount of IL-6 in GAgP patients increased strongly compared with control group (p<0.0001). There was no significant difference between the two groups concerning the level of IL-12. CONCLUSION: There is an association between generalized aggressive periodontitis and low level of IL-4 as an anti-inflammatory cytokine, and high level of IL-6 as a proinflammatory cytokine. No correlation between IL-12 and generalized aggressive peridontitis was found.