marzieh ahmadi

The drying of the river in recent years has caused disruption of the river ecosystem and loss of aquatic life and vegetation. Among the other main problems of the drying up of the Zayandeh Rood River, the following can be mentioned: disturbance of the form and process and function of the geomorphology of the river, loss of vegetation, destruction of the aquatic ecosystem and water pollution, reduction of the groundwater level. And finally, the destruction of the environment of the Gavkhoni wetland and as a result of it becoming a center of micro-pollution and from the point of view of the city dwellers, tourism has decreased, the view and the beautiful view of the city along the river has also been lost. This issue has also had a negative impact on the microclimate of the city. Therefore, it is necessary to carry out deep and comprehensive studies and investigations on the current morphological and hydrological conditions of the river in order to minimize these problems and issues by finding suitable solutions. Considering the drying up of Zayandeh Rood river and severe human changes in this urban river, the purpose of this research is to evaluate the condition and morphological quality of Zayandeh Rood river in the urban part of Isfahan. For this purpose, the MQI morphological quality index method will be used. This method is a new method for classifying the quality and performance of rivers. This method provides an approach to evaluate the morphological quality of rivers and its improvement strategies by considering all river forms and processes, past analysis and adjustment and changes of the river channel.

In this research, the morphological quality of the Zayandeh Rood River has been investigated and analyzed with the MQI model (from Najvan Park to Ashkavand Bridge). In this study, a 16 km path of the river was divided into 6 sections.The River Morphological Quality Index (MQI) method consists of two main phases and several sub-phases. The first phase studied the current trends in the assessment of the morphological conditions of the river and includes the investigation of the natural characteristics of the basin, the investigation of the morphology of the river channel and the division of the river. These ranges represent the primary units for evaluating morphological conditions In the second phase, to evaluate the morphological quality of river basins, the following three aspects are taken into consideration: Continuity of river processes, including longitudinal and transverse continuity, The morphological conditions of the conduit including the conduit pattern, cross section shape and bed sediments, Vegetation.

To implement the MQI method, the area and route of this 16 km section of the river from Najvan Park (Kalamkar Bridge) to Ashkavand Ring Bridge was divided in the inner city and the urban outskirts of Isfahan. This division is based on criteria such as changes in the width of the channel, changes in the width of the alluvial plain, the presence of bridges, the presence and changes of marginal vegetation, the presence of artificial structures, the channel planform (straight, winding), the presence or absence of banks It is fixed, the changes in the size of bed sediment, as well as field investigations and visual evaluation of Google Earth images, and it was divided into 6 intervals. The morphological quality of the river basins including: continuity of river processes, morphological conditions of the channel and vegetation were evaluated. With field studies, the use of Google Earth images and the implementation of the MQI model, the results of this research showed that the first, fifth, and sixth ranges with scores of 0.57, 0.66, and 0.58 are in the category of medium morphological quality, these ranges are outside the urban area. are located and geomorphologically, they are in a better condition than other ranges. The second, third, and fourth ranges are located in the urban area with scores of 0.38, 0.41, and 0.48, respectively, and have suffered the most human changes and are in the weakest state in terms of geomorphology.

By classifying the types of river channels and evaluating their morphological and functional quality, it is possible to use many specific management solutions, including various restoration methods and hard to soft engineering to improve their conditions. Regarding the revitalization of the Zayandeh Rood urban river, it is necessary to consider the basic flow of water for the river by respecting the water rights of the river and providing a minimum discharge, reducing the pumping of water from the river upstream for agricultural purposes, especially in the highlands.In the field investigations that were conducted in the study route and six river sections, the complete dryness of the river bed, longitudinal sedimentary barriers were created, some rocky outcrops, islands and sedimentary barriers between channels, mainly artificial sedimentary embankments, destruction of natural vegetation, changes Land use and human intervention and stabilization of the banks were clearly observed.

Some studies indicated that membership in social networks could lead to overweight or obesity. Other studies showed that social networks and the Internet could affect people's nutritional status. Therefore, this study aimed to examine the effect of social networking on students' attitudes and eating habits. This study is a descriptive survey conducted among students. A questionnaire designed in four main parts to measure students' nutritional status and attitude was used as an instrument. Three hundred sixty-four (364) students participated in this study. In addition, a Chi-square test was used to determine the relationship between the variables. Most participants in this study were female and single, and Telegram was the social network with the most users. The participants believed that spending time on social networking did not significantly change their tendency to get more nutritional information. Also, respondents to the questionnaire stated that there was no significant change in their food consumption patterns following social networking. Moreover, the results explained a statistically significant difference in the participants' dietary beliefs due to social networking (p<0.001). Although the effect of social networking on users is a fact, and most of the participants used social networking and were members of several channels, the role of social networking in students' nutrition status was not confirmed. However, social networking could change the students' nutritional beliefs.

The culture of planning in the school and achieving the predetermined goals and missions is central to school management. The current research was conducted with the aim of designing an optimal school-centered management model in education. The statistical population of the research includes principals, assistants, teachers and other personnel of schools in Fars province, which are more than 50000 people. Research information was collected in two qualitative (interview) and quantitative (researcher-made questionnaire) sections. In the qualitative section, after semi-structured interviews with the interviewees and through open, central and selective coding, 20 main categories (decentralization, delegation, responsibility, empowerment, commitment, flexibility, participation, organizational culture, accountability, independence, trust and respect, economic and Facilities, social, talent and creativity of students, type and conditions of school, educational content, meritocracy, justice, mission and non-discrimination) and 60 sub-categories were identified for school management. 100 questions in the questionnaire for the components (5 questions for each component) were designed and distributed and collected among 382 people from the statistical population. The results of the research showed that all the above components are effective on school-centered management. Due to the large amount of information through exploratory factor analysis (with factor loading equal to 0.5), the number of 30 questions were placed in three main factors (independence and facilities, selection of competent, social and justice-oriented managers, sharing of information and goals in the organization). They explained 40.6% of the total variance. The general fit indices of the school-centered management model indicate an acceptable fit and high validity of the designed model.

The notion of educational service quality is multifaceted and arises from the perceived variance between students' expectations from the educational system and the services they actually receive. The progression of universities has shifted from a quantitative phase to a qualitative one, and as such, it has become necessary to assess the quality of university services. This research was conducted to evaluate the educational service quality at Gorgan Dental School.

A cross-sectional descriptive study was conducted in 2021, among dental students attending Gorgan Dental School, Golestan University of Medical Sciences. Data were collected using the SERVQUAL model questionnaire, which was devised considering the five domains of service quality. Descriptive statistics and inferential statistics were used in SPSS 23 to analyze the data.

 A total of 103 students, with an average age of 23. 09±3. 31 years, participated in this study. Most of the students were female (59%) and the rest were male (44%). The average overall score of expected service quality was 4.52±0.49 and the overall average score of perceived service quality was 3.09±0.71. The overall average gap in service quality was -1.44±0.79. The greatest gap was noticed in the responsiveness domain (-1.58±1.05) and the least gap was found in the tangible domain (-23.1±0.92).

There was a gap in all aspects of the quality of educational services and related terms, which shows that the expectations of students have not been completely met. In order to resolve this gap, meticulous planning and effective management of educational services should be enacted.

The culture of planning in schools and achievement of predetermined goals and missions serve as the foundation for school-centered management. This research aimed at examining the effectiveness of the school-centered management model and environmental conditions on students’ academic performance, with the moderating role of ethical values.

The research method employed an exploratory mixed methods approach, incorporating both qualitative and quantitative elements. In the qualitative phase, the main and sub-factors of the school-centered management model were extracted using thematic analysis. Additionally, the quantitative phase utilized a descriptive-survey method. The data collection instrument in the qualitative phase consisted of semi-structured interviews. In the quantitative phase, a researcher-developed questionnaire was designed based on the research components, comprising 107 items measured on a 5-point Likert scale. The qualitative sample included 12 beneficiaries in the education system of Fars province, including managers, deputies, teachers, and other school staff. The sampling method was purposive and saturated. The statistical population in the quantitative phase consisted of managers, deputies, teachers, and other school staff in the education system of Fars province, and the sample size was determined using Krejcie and Morgan’s table (1970), amounting to 382 participants. Clustered multi-stage sampling was employed in this section.

The research questions were analyzed using Smart-PLS3 software. The results of the study indicated that ethical values have a positive impact on the performance of students’ educational content. Moreover, environmental conditions and school-centered management significantly and positively influence the performance of students’ educational content. Ethical values enhance the impact of environmental conditions on the performance of students’ educational content while reducing the impact of school-centered management.

Furthermore, the overall model fit is strong and acceptable (GOF=0.381).

Tobit method is applied in this research to consider in three sections, the effective factors on transportation demand of the people of Tehran. Results of applying tobit method to consider effective factors to use autobus and minibus (public transportation system) show that there is a meaningful and negative relation with income level, number of family members, number of educating members and number of male members, but this relation is meaningful and positive for the number of employed members. The age of head of family has meaningful and positive relation with using public transportation system only during third three decades of age. There is also no meaningful relation with other age groups and education level of head of family. Consideration of effective factors to use public taxi and telephone taxi by tobit method shows that there is a meaningful and positive relation with income level, educating members, number of employed members and education level of head of family in second and third levels of education. The relation between age of head of family and using public and telephone taxi is meaningful and positive only in fifth decade of age. As the results show, there is no meaningful relation with number of family members and number of male members. Tobit method to consider effective factors to use subway shows that there is a meaningful and positive relation with income level, number of family members, number of educating members and education level of head of family but this relation is meaningful and negative for number of male members of family. The relation with the age of head of family is meaningful and positive only in fifth decade of age and there is no meaningful relation with the number of employed members of family.

Financial markets play a key role in economic development, and the insurance industry as a financial institution can be the bedrock of economic growth. Thus, risk and performance appraisal are very important in the insurance industry. There are several methods for evaluate risk and efficiency in financial markets, but since the performance of insurance companies is different from other financial institutions for the risk acceptance of other organizations and individuals, it is necessary to rank factors affecting efficiency and risk in insurance companies separately based on the performance of companies prior to focus on the calculation method. This paper discussed factors affecting the financial risks of insurance companies and efficiency and their rankings using the Delphi qualitative method and collecting expert’s opinions as well as data from domestic and forign papers. The statistical population of the research is experts and specialists in the field of risk and insurance. Spss, Eviews and Excell 2013 were used to review the questionnaires and estimate the results. The results of this paper identified the factors affecting each of the risks of financial wealth, liquidity, credit, operations and efficiency, and in the ranking obtained through Friedman test, efficiency is the highest rank, followed by liquidity, operational and credit risk in the rankings.

Because students receive a variety of educational services during their studies, their view of the services provided can be considered as one of the characteristics of quality in the university. This study was conducted to determine the quality of educational services from the perspective of nursing students.

A cross-sectional study was performed in the School of Nursing of Golestan University of Medical Sciences with a sample of 164 people. The data collection tool was a valid and reliable SERVQUAL questionnaire. Data analysis was performed using SPSS-23 statistical software.

In all five dimensions of educational services (physical dimensions, guarantee, accountability, confidence, and empathy) there was a negative gap between the current and desired status of students and the quality of educational services. The highest mean gap was in the dimension of empathy and responsiveness (-1.73) and the lowest mean gap was related to the tangible dimension (-1.43). The age of students was directly and significantly related to the quality gap in the dimensions of confidence (P = 0.028) and empathy (P = 0.046). Gender of students with total quality gap (P = 0.004) and in the dimensions of confidence (P = 0.018), accountability (P = 0.003), guarantee (P = 0.013) and empathy (P = 0.001) P) and students' education also had a significant relationship in terms of confidence (P = 0.001).

Students' expectations are beyond their perception of the current situation and in none of the dimensions, their expectations have been met. Holding effective communication training courses and receiving feedback can play an effective role in improving the quality of educational services.

This paper designs an Optimized Adaptive Combined Hierarchical Sliding Mode Controller (OACHSMC) for a time-varying crane model in presence of uncertainties. Uncertainties have always been one of the most important challenges in designing control systems, which include unknown parameters or un-modeled dynamics in systems. Sliding mode controller (SMC) is able to compensate the system in the presence of uncertainties due to un-modeled dynamics and is used for robust stability and performance behavior in the presence of additive un-modeled dynamics of system and multiplicative friction forces. This under-actuated crane has two sub-systems: trolley and payload. Therefore, it can be controlled by a single input signal with combined hierarchical sliding mode controller (CHSMC) using a two-layer-sliding manifold accurately. Payload mass and cable length are time-variant variables through load transferring. Due to the Time-varying models and the inefficiency of most controllers, the use of an adaptive controller can help improve system performance. This controller is adapted by considering a time-varying coefficient of the second layer sliding manifold. For energy saving of the input signal, the parameter of the first layer sliding manifold of ACHSMC is optimized by two intelligent strategies: genetic algorithm (GA) and particle swarm optimization (PSO) method. The simulation results show robust stability and performance of the proposed optimized controller.

Regarding the bilateral relationship between financial decentralization and regional development at the national level, this study examines the relationship between regional inequality and vertical balance financial decentralization across the provinces of Iran. For this purpose, the calculations are carried out in two stages: in the first stage, the Composite Index of Regional Development (CIRD) is calculated in five dimensions (macroeconomics, science and innovation, environmental sustainability, human capital and public services) by using the two-stage principal components analysis (PCA) during 2006-2016. In the second stage, the interactions between vertical balance financial decentralization and regional development are estimated using the simultaneous equations and error component two-stage least squares (EC2SLS). The results of the first stage analysis show that Tehran province is at the highest level of development, and Sistan and Baluchestan province is at the lowest level of development, and these two provinces practically reflect the wide inequality in the provinces of Iran. In addition, the highest regional inequality is related to the dimensions of science, innovation and human capital. The results of the second stage indicate that the effect of vertical balance financial decentralization on negative regional development is significant and negative, meaning that if provinces spend based on their income, a slight decrease in provincial development has it Because provinces play lesser role in determining tax rates and bases, less developed provinces are not able to generate sufficient revenue to cover their provincial expenditures. Financial decentralization also increases with an increase in regional development, meaning that provinces with different levels of development are likely to have different tendencies toward the quality and quantity of public goods.

Language teacher immunity has recently attracted the attention of the scholars interested in teacher psychology. Following the previous line of research in teacher psychology, the present study explored the immunity types among 260 Iranian EFL teachers working in schools and language institutes. Drawing on Hiver’s (2017) categorization, this study found that the participants were classified into productively and maladaptively immunized teachers through cluster analysis. It was also found that gender played a significant role, and female participants were more productively immunized than men. Regarding the role of teaching experience, it was found that EFL teachers’ immunity fluctuated in the late stages of their practice to a more fossilized, negative one. Regarding age differences, the results also suggested different immunity types among the participants of different age groups. The results implied that teacher education programs should enhance EFL teachers’ understanding of language teacher immunity as an important factor in their effectiveness and well-being as well as students’ achievement.

Urinary incontinence is one of the clinical symptoms of pelvic floor muscle instability whose potential role in the body balance has been suggested. The present study aimed to compare static and dynamic balance indices in women with and without Stress Urinary Incontinence (SUI).

In the present cross-sectional analytic study, 15 women with and 15 women without SUI were enrolled. After collecting demographic data, the static balance indices, time to stability, rate of loading during landing, and ground reaction force during walking were measured using the force plate device. Independent t tests were used for data analysis and the significance level was set at p≤0. 05.

The length of the route of the center of pressure in the anterior-posterior (p=0.004) and lateral (p=0.002) directions, the velocity of the center of pressure in the anterior-posterior (p=0.004) and lateral (p=0.002) directions, and length of total path traveled with open eyes in women with and without SUI had significant difference. All of the static balance indices were significantly different between the two groups (p< 0.05). Time for stability in the vertical (p=0.001), anterior-posterior (p=0.008), and lateral (p=0.044) directions in the group without SUI was significantly less than that of the group with SUI.

Based on our results, almost all static and dynamic balance indices were weaker in women with SUI than in women without SUI. Therefore, it can be concluded that pelvic floor muscles, as a part of core muscles, play an important role in postural control.

The usual methods of measuring regional inequalities can not reflect the internal changes of the country in terms of displacement in different development groups. Thus, the indicators of inequalities are not effective in demonstrating the dynamics of the distribution of inequalities. For this reason, this paper examines the dynamics of the regional inertial transport in the country during the period of 2006-2016 using the CIRD multidimensional index and stochastic kernel density method. To that end, 25 indicators were selected in five dimensions including macroeconomic conditions (MEI), science and innovation (SII), environmental sustainability (ESI), human capital (HCI) and public facilities (PFI). In turn, a two-stage Principal Component Analysis (PCA) methodology was developed to create a composite index of inequality. Then, in the second stage, using a nonparametric analytical approach to internal distribution dynamics and a stochastic kernel density method, the convergence hypothesis of the CIRD index of the Iranian provinces was tested. Afterwards, based on the ergodic density, the long-run equilibrium was shown. At this stage, to adopt the most accurate regional policies, the distribution dynamics and the process of convergence or divergence of the Iranian provinces for each of the five dimensions in three successive periods (2006 and 2016) were studied separately. According to the results of the first stage in 2006, the highest level of development was related to Tehran province, followed by Semnan, Yazd and Markazi provinces. In turn, Sistan and Baluchestan province had the lowest level of development. In 2016, the highest level of development and the highest positive inequality were in Tehran, Yazd, Semnan and Isfahan provinces and the lowest level of development was in Sistan and Baluchestan, Chaharmahal and Bakhtiari, North Khorasan and Kurdistan provinces. The results showed that the central provinces of the country were at the highest level of development due to the effects of Tehran's knowledge spillover, while the country's lower provinces were at the lowest level of development. The main reason for this may be due to the lack of access to the markets in the border provinces. Based on the results of the second stage, which examines the dynamics of regional inequality transmission in the country during 2006-2016, the first year (i.e., 2006) was not multifaceted and according to the kernel density graph, the CIRD index of about 70% of the provinces was between -1.1 and -0.1. The rest of the sequence on the right was distributed at a level higher than -0.1. In the kernel distribution, a convergence process was observed. One peak was about 1 and the other about 3, but the main peak remains at -0.6 with about 55 percent of the provinces. In the second year (i.e., 2011), according to the kernel density diagram, the curve clearly showed the pattern of the triplet nature and there was a small but a clear increasing trend in the distribution of this year relative to 2006. In this year, the previous uniform distribution is divided into two parts at the highest level, one peak at about 1 and the other at about 3. However, the main peak remains the same at -0.6 with approximately 55% of the remaining provinces. In 2016, the multidimensional pattern remained constant and there was no mobility in the lower level groups. On the contrary, at the higher level, the CIRD index accounted for about 45% of the provinces at about -0.4. This year clearly faces the twin density pattern, indicating that the provincial provinces tend to be closely related to each other in terms of development. This way, the provincial provinces are low in terms of development. The findings tend to be -0.6 and the value of the more developed CIRD index tends to be about 0.4. These three curves show that the provinces tend to converge toward several different CIRDs in terms of development. Moreover, according to the distribution dynamics results, the provinces of Iran followed the single-density pattern in 2006. However, in 2016 they followed the double-peak density pattern in low and moderate inequality index levels as well as in the development index. In conclusion, the country diverged during the years 2006 to 2016.

Regarding the dual relationship of various studies between financial decentralization (expenditure and income) and regional development at the national level, this study examined the relationship between regional inequality and financial decentralization (expenditure and income) in the provinces of the country. For this purpose, the calculations were carried out in two stages: In the first stage, the index of regional inequality (CIRD) on 5 dimensions (macroeconomics, science and innovation, environmental sustainability, human capital and public services) is calculated by using the principal component analysis (PCA). This index is the development composite index that it is calculated for the years of 2006 and 2016. In the second part, using the simultaneous equations (SEs) and error component two-stage least squares (EC2SLS), examine the dual relationship of financial decentralization (expenditure and income) and regional development. In the next section, which examined the interaction of financial decentralization variables and regional development, the effect of both decentralization variables on regional development index are significant but the effect of financial decentralization of expenditures on increasing regional development is greater than the effect of financial decentralization of income.

Neutrophil-to-lymphocyte ratio (NLR) is considered as an independent predictor of long-term prognosis in the individual patients with coronary artery disease (CAD). This study sought to assess the relationship between NLR and CAD severity in Iranian patients undergoing cardiac catheterization.
Material and This prospective study was conducted on 500 patients with acute coronary syndrome (ACS) presented to Shahid Beheshti Hospital, Qom, Iran, for admission and underwent cardiac catheterization between March 2015 and May 2017. The patients were assigned into three groups of high NLR (more than 3), intermediate NLR (between 2 and 3), and low NLR (less than 2). Then the CAD severity and its relationship with NLR were assessed.
According to the results, there was a significant difference between the groups in terms of CAD severity (P Given the results of this study, high NLR was associated with CAD severity.

ýýIn this paper we determine all finite 2 -groups ofý ýclass 2 in which every automorphism of order 2 leaving the Frattini subgroup elementwise fixed is innerý.

The relationship between technology and international competitiveness dates back to the neo-technological trade theories of the 1960s. This approach considers difference in technology as the primary motive for difference among nations in terms of trade performance. The technology gap approach emphasizes inter-country differences in innovativeness as the basis for international trade flows. The gravity equation is the most successful and celebrated empirical model in international Trade. The empirical gravity literature does not include any form of multilateral resistance in the analysis. The importance of using fixed effects to control for country-specific characteristics has been emphasized in an influential paper by Anderson & Van Wincoop (2003). This paper investigates the effect of innovation on international trade. It examines the impact of R&D as a proxy of innovation on three medium high-tech industries exports in Iran, Japan, Korea and Australia using panel data method over a period of 10 years. We incorporate an industry-specific intercept into the model for estimating the role of innovation in explaining industry-level trade across selected countries. Our findings show that innovation has a positive and economically large effect on export performance of all industries. This suggests innovation is a central driver of trade.

Uterine myoma is a common benign, solid tumor in women with reproductive age. Thrombosis factors play a major role in tumor formation and also tumors induce thrombotic processes. Factor V (FV) and factor 13A1 (F13A1) are two thrombotic factors, which their dysfunctions affect the clot formation. FV Leiden, a common mutation in F5 gene, and V34L mutation in F13A1 gene are known to affect the risk of thrombosis. The purpose of the present study was to determine the possible association of FV Leiden and F13A1 Valine to Leucine at codon 34 (Val34Leu) mutations with the risk of developing uterine myoma in the women from south of Iran.
In this case-control study, FV Leiden and V34L mutations were genotyped in 73 myoma patients and 73 healthy subjects using amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). The data were analyzed by logistic regression, χ2 test and SPSS software version 16.0.
Regarding the results, only F13A1 V34L mutation was associated with myoma. The Val allele showed the protective role on myoma among the studied population (OR: 0.49, 95% CI: 0.24 - 1, P = 0.05). In addition, we found that individuals with F13A1 V/V (OR: 0.09, 95% CI: 0.005 - 1.8, P = 0.04) and V/L (OR: 0.1, 95% CI: 0.006 - 1.98, P = 0.042) genotypes had a significantly lower risk of myoma tumor compared with the other genotype (L/L). Moreover, there was no association between V34L mutation and myoma after adjusting the data for the factor age (P > 0.05).
Our results introduce the F13A1 V34L mutation as an age-related risk factor for myoma.

This paper proposes the design of a nonlinear optimal controller for a submarine with nonlinear model with six degrees of freedom (6-DOF). The control aims includes achieving system stability، reaching the submarine to a desirable point at the end of the maneuver، and choosing the optimal path that are accessible by solution of optimal cost function. The novelty of this paper is the systematic step selection in the gradient descent algorithm that has increased the rate of convergence beyond two times rather than fixed step algorithm. Finally، via some simulations، the robust performance of the designed controller for moving in different depths with considering of parametric uncertainty has been confirmed.

In this paper, finite element model of the L4 vertebra subjected to combination of compression and flexion loading in isotropic and anisotropic cases is investigated. In both cases, the vertebra is considered homogeneous. Also, the body of vertebra is divided to cancellous and cortical sections in anisotropic model, but the process is assumed isotropic such as isotropic model. The maximum Von Mises stress on the fourth lumbar vertebrae is obtained. Also, the stress intensity factor is analyzed with placing a small crack on the critical region of the model from view point of fracture mechanics. Furthermore, the required force for the fracture of fourth lumbar vertebrae is obtained through increasing the applied force for assumed model. The results show that the highest stress value and its position is 7.237MPa in the upper pedicle region for anisotropic property of vertebrae. At the end of this article, stress intensity factors in different aspect ratios of crack for anisotropic vertebrae under combination of flexion and compression loading are plotted.

Membrane bioreactor systems are extensively used in biological treatment of the municipal and industrial wastewater. Despite the efficiency of these bioreactors in biological wastewater treatment, several problems, including bacterial biofilm formation, have limited their use. This study aimed to identify the dominant bacteria in the biofilm of such systems as well as to investigate the lethal effect of the silver nanoparticles in small size (4 nm) and higher dilutions in wastewater. This laboratory-scale experimental study was performed on 140 samples; the dominant isolates were identified using the differential biochemical tests. Using Broth micro dilution, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were calculated. Standard discs were prepared by different concentrations of nanosilver particles (0.5, 1, 2, 4, 8 ppm) and evaluated through the disc agar diffusion method on Muller-Hinton agar plates. Finally, the inhibition zone diameter was measured. The frequencies of isolates were Escherichia coli, Pseudomonas aeruginosa, Proteus, Bacillus subtilis, Bacillus cereus, Citrobacter and Bacillus anthracis, respectively. Moreover, The MIC of sliver nanoparticles (4nm) against the isolates were as follows: Escherichia coli, 2ppm; Citobacter, 1ppm; Bacillus cereus, 1ppm; Bacillus anthracis, 0.5 ppm; Bacillus subtilis, 1ppm; Pseudomonas aeruginosa, 4ppm and Proteus, 2ppm. It can be concluded that silver nanoparticles, with a particle size of <10 nm, have a positive impact on the removal of dominant resistant isolates, especially gram-positive bacteria.