mohammad javad jafari

Banks and financial institutions are the driving force of every country's economy due to their central role in financing and circulation of money and wealth in the society. Any disruption in their operations will leave very destructive effects on the financial system of countries, which can lead to monetary crises and have unpredictable economic and even social, political and security consequences; Therefore, in the monetary systems of the world, how to deal with this phenomenon is of particular importance and is done with great sensitivity. The purpose of this article is to examine the suspension of bankruptcy of banks and financial and credit institutions and the role of the central bank in bankruptcy and settlement operations.

This article is descriptive and analytical. Materials and data are also qualitative and data collection was used in collecting materials and data.

Ethical Considerations:

 In this article, the originality of the texts, honesty and trustworthiness are respected.

The findings showed that the central bank has a supervisory role in verifying the suspension and liquidation of the bankruptcy of banks and financial institutions, and this supervision is discretionary.

The criterion for stopping the bankruptcy of banks and financial institutions is the supervisory threshold that is determined in monetary and banking regulations.

This article was compiled with the aim of examining the possibility of filing a lawsuit for loss of opportunity in Iran's legal system and judicial procedure with a review of American law. In this article, the legal concept of loss of opportunity and its relationship with similar concepts such as loss of benefit and lack of benefit have been analyzed. Our goal in this research is to compare the legal system of Iran and America regarding the lost opportunity.

The research method in this article is descriptive, analytical and library method.

Ethical Considerations:

 From the beginning to the end of the article, the principles of honesty and trustworthiness have been observed.

The findings indicate that the existence of disagreements between jurists and jurists on the one hand, and the discussion about previous and current laws in accordance with the American law, on the other hand, creates serious challenges in this field; Because the legal system derived from jurisprudence in Iran, whose effects and signs are evident in the legislative process, on the one hand, they believe in compensation for the loss of opportunity, and on the other hand, some people do not consider these losses to be compensable.

Finally, the interpretation of civil laws, the opinions of jurists and the judicial procedure lead us to the conclusion that the damages caused by the loss of opportunity can be compensated without a doubt if they are real and definite.

In the present article, forced vibration control of Timoshenko’s micro sandwich beam based on modified couple stress theory (MCST) is studied. The face sheets are made of three-phase reinforced nanocomposite including resin, piezoelectric and CNT\CNR\GPL materials, and top and bottom layers operate as actuator and sensor, respectively. The micro sandwich beam is placed on Kerr’s foundation and subject to harmonic force with resonance excitation frequency. By considering the equations of motion in the state-space form and using LQR, the amplitude of forced vibrations of the micro beam is optimized. Furthermore, the effects of various parameters including the volume fraction of CNT, GPL and CNR, three parameters of Kerr’s elastic foundation and three natural frequency modes on the suppression and settling time and forced vibration response of a micro sandwich beam is investigated. In this research, for various types and volume fractions of nanocomposites, the second and third natural frequency modes increase 3.5 and 6.7 times, respectively, compared to first natural frequency mode. Also, the Kerr foundation increases the first, second and third mode of natural frequency by about 46%, 13.1% and 7.7%, respectively.

The rescission condition is one of the clauses that is sometimes included in contracts by mutual agreement of the parties, stipulating that if either party regrets the concluded transaction, they must pay a specified amount to the other party. In applying the rescission condition in contracts, the parties do not specify a specific duration. This condition does not align with any of the types of options provided in civil law, and the legislator has not clearly defined a specific approach regarding this matter, leading to differing opinions and a lack of consensus in existing practices. The concept of condition is a key topic in jurisprudence, and understanding it accurately is crucial for analyzing related legal rulings. A condition refers to a future event that the parties consider to have legal effects. In legal principles, a condition is any factor whose existence is essential for the realization of another matter. In legal and jurisprudential terminology, this term signifies a general obligation that can exist within a contract or independently.The option condition is unanimously accepted among jurists of both Sunni and Shia schools, based on consensus and tradition. In Iranian law, the option condition is determined by mutual agreement of the parties; otherwise, according to Article 401 of the Civil Code, both the option condition and the contract are void. Iranian courts do not have a unified approach regarding one of the applications of the option condition, namely the condition of withdrawal or rescission of the transaction. Some view this as rendering both the condition and contract void, while others consider the condition void but uphold the contract's validity. Additionally, some believe that this condition does not constitute an option but rather represents a form of compensation aimed at reinforcing the transaction.

The condition of regret is one of the conditions that is included in contracts, and on the other hand, it is not in accordance with any of the options in civil rights. No, it is a matter of disagreement. Based on this, the purpose of this article is to examine the effects of the regret clause in contracts in Iranian and Egyptian law. 

The present article is descriptive and analytical, and data collection was used in data collection. 

Ethical Considerations:

 In this article, the originality of the texts, honesty and trustworthiness are observed. 

In Iran's civil law, there is no condition under the title of remorse condition.There is a difference of opinion in this regard in legal doctrine. Some consider it to be the same as the option of the condition, some with the obligation, and some with the cancellation. But it is a kind of condition that is raised according to Article 10 of the Civil Law in order to strengthen the contracts. Deprivation of execution, annulment and liquidation of the contract are the most important effects of the condition of regret in contracts. 

According to the principle of the necessity of contracts, the condition of regret should be narrowed down to the minimum valid and certain cases of that interpretation. Accordingly, in the condition of regret, the condition of paying damages is stated.

WBV and heat stress are important hazardous agents, which can affect the people’s cognitive function. The present study aimted to explore the effect of co-exposure to heat stress and WBV on auditory-visual attention and reaction time in a laboratory setting.

The present study was conducted on 32 consenting male students chosen from the university in accordance with the inclusion criteria. The participants were required to complete the General Health Questionnaire (GHQ-28) in order to determine their state of health. The Ishihara color blind test was performed afterward. Heat stress exposure was exerted at a WBGT index of 22, 29, and 34 °C, with 22 °C as the control condition. WBV was applied at 0.53, 0.81, and 1.12 m/s2, as well as a no WBV exposure condition (the control), making a total of 12 different exposure modes. The reaction times and auditory-visual attention of the subjects were measured via the IVA test. Further, the individuals’ heart rate was recorded by a digital heart rate monitor.

Elevation of WBV acceleration and WBGT from 29°C to 34°C independently caused a significant reduction in auditory-visual attention, as well as a significant rise in reaction times. Co-exposure to WBV and heat stress significantly affected auditory-visual attention and reaction time (p<0.001).

According to the results, WBV and heat stress are two influential factors on cognitive performance which can reduce concentration and attention devoted to work.

Customer churn presents a significant challenge for the telecommunications industry, necessitating effective strategies for prediction and prevention. While prior research has explored diverse methodologies, including Agent-based Modeling (ABM), limitations persist. Existing approaches often rely heavily on theoretical constructs, resulting in oversimplified models and constrained data utilization. This study addresses a critical research gap: the absence of a comprehensive framework integrating empirical data, agent-based modeling, and machine learning techniques for churn prediction in telecommunication markets. By bridging the gap between theoretical abstraction and empirical reality, proposed framework enables more proactive churn management strategies. Additionally, it facilitates the simulation of diverse market scenarios, empowering stakeholders to optimize key metrics such as revenue and market share. Through the implementation of the proposed framework within a specific telecom market scenario involving two competing entities, this study demonstrates its efficacy in achieving desired market share objectives. This research contributes to advancing the understanding and management of customer churn in the telecommunications industry.

The principle of passive sound control is based on the phenomenon of sound absorption by absorbers. The factors affecting sound absorption include porosity, pore size, pore opening size, thickness, and air flow resistance.

In this study, the authors compared the optimization results of the effective parameters on sound absorption coefficient (AC) using the three optimization methods Guided Local Search (GLS), Genetic Algorithm (GA) and Particle Swarm Optimization (PSO). The programming was done in MATLAB software. Thicknesses of 5, 10, 20, 30 and 40 mm were chosen for optimization at frequencies of 500 to 3000 Hz.

In frequencies above 2 kHz (thickness 5 to 40 mm), the three optimal methods had the same performance and estimated AC of 1. At low frequencies of 2 kHz and thicknesses of 30 and 40 mm, GA and PSO methods obtained an AC of 1.

It seems that the GA and PSO optimization algorithm are suitable methods to optimize the AC of metal foam in low and high frequencies.

Exposure to heat and noise can have negative impacts on cognitive and behavioral performance in various work and non-work settings. Therefore, this study was conducted with the aim of providing a model based on a multilayer perceptron neural network for occupational exposure classification of different levels of noise and heat.

This study involved the examination of 72 voluntary students, aged between 23 and 33 years. The input data provided to the neural network included cognitive, behavioral, physiological, and neurophysiological information. The output layer of the network was designed to classify exposure to various levels of noise and heat into three categories: lower, higher, and within permissible limits.

In this study, a two-layer neural network (15:10) was considered as the optimal model, with a chance of approximately 33 percent for correctly classifying the data. To evaluate this model, accuracy percentage, mean squared error (MSE), and sensitivity were calculated. The classification accuracy for different levels of noise and heat during the learning phase was 93.87 percent, and during the testing phase was 92.62 percent and the validity of 92.68 percent. Additionally, the mean squared error percentage was 0.53, and the sensitivity percentage was 90.42.

The present study demonstrated that the proposed model based on a multi-layer perceptron neural network has an acceptable accuracy and sensitivity for predicting different classes of noise and heat using psychophysiological and neurophysiological input data.

Adherence to the obligations resulting from international treaties such as the United Nations Charter and the obligations arising from it, including the Security Council resolutions in the legal system of the Islamic Republic of Iran, which is influenced by the powers of the legal guardian, has different theoretical foundations from other states. Although Article 25 of the United Nations Charter obliges the member states to accept and implement the decisions of the Security Council, and the organization's practice considers at least the resolutions issued based on the seventh chapter of the Charter to be binding, however, the Islamic Republic of Iran has always been critical of the actions of this organ due to the fact that it sees most of the Security Council's decisions as detrimental to itself. Resolutions 598 and 2231 of the Security Council, the first of which ended the war and the second of which temporarily ended the nuclear conflict between Iran and the West, although it has finally been approved by the highest political authority in Iran (supreme leader), this acceptance was not done out of commitment to international obligations and requirements arising from the Charter, but simply by adhering to and appealing to political-jurisprudential standards. The investigation of this research is analytical-descriptive and the method of collecting information is library. The question of this article is about the position of the resolutions of the Security Council in the fundamental rights of the Islamic Republic of Iran, and the hypothesis that is raised is that since the system governing the Security Council is unfair, oppressive and a reflection of the system of domination in the eyes of the leaders of the Islamic Republic, therefore, the possible acceptance of the aforementioned resolutions is not based on international obligations and its norms, but on the basis of politics.

One of the important categories in Iran is cultural diversity. The purpose of this article is to examine the question of what place cultural diversity has in the constitution of the Islamic Republic of Iran and what are the solutions for cultural diversity in the Islamic Republic of Iran from the perspective of political sociology? This article is descriptive and analytical, and data collection has been used in data collection. The findings indicate that cultural diversity is formed in appropriate political and social contexts. Cultural diversity is recognized in Iran's constitution. Several principles of the constitution deal with the issue of culture and cultural rights, such as the right to free education, the right to freedom of communication and information, and the right to equality in enjoying all cultural rights. Cultural diversity in Iran's constitution includes three cultural elements, namely, language, religion and way of life. It seems that one of the challenges and problems facing cultural diversity is the non-recognition of cultural rights in an independent form and the non-allocation of a specific annual cultural budget from the government. The opportunity to consider cultural diversity, view cultural diversity as the foundation of security, adopt multicultural policies in general and multicultural education policies in particular, pay attention to social realities and intercultural sensitivities, intercultural communication, intercultural education and intercultural dialogue are among the most important It is a solution to strengthen cultural diversity in the Islamic Republic of Iran from the perspective of political sociology.

Heat stress is the most physically harmful factor in open and closed industrial environments. It affects people's cognitive and mental functions, causes the speed of fatigue, reduces concentration and skill, and increases the amount of errors. Therefore, the current research has The Effect of Heat Stress Exposure on Visual- Auditory Performances of subjects in laboratory conditions.

This study was conducted on 32 male students of Shahid Beheshti University of Medical Sciences, aged 20 to 29, who were selected according to the condition of consent and meeting the inclusion criteria. Environmental heat stress was applied at three levels of temperature index of 22, 29, and 34 degrees Celsius, and the temperature index of 22 degrees Celsius was considered as the laboratory background condition. Then, they were studied in different laboratory conditions, including exposure to heat stress. The subjects' attention level and reaction time were evaluated using the Integrated Visual and Auditory Continues test tool. The participants completed the written consent form, demographic information form, and general health questionnaire. Also, the subjects' heart rate was recorded with a digital heart rate monitor.

This study showed that the amount of visual and auditory attention decreased significantly (p<0.001). The reaction time of people increased significantly under the influence of heat stress (p<0.001).

The results showed that exposure to heat stress are an effective factor in reaction time, attention level, and heart rate, which can reduce accuracy in doing work. Therefore, paying attention to the amount of thermal stress in working environments plays an important role in improving the speed and performance of people.

Iran's criminal law allows the punishment of the perpetrators to be intensified in the real multiplicity of the crime, but not in the spiritual multiplicity. However, it is not always easy to distinguish the spiritual multiplicity from the real one. Based on this, the aim of this article is a comparative study of spiritual multiplicity of crimes in Iranian and French laws. This article is descriptive and analytical and has investigated the subject of reference using the library method. The findings indicate that the legislator in the 2019 Penalty Reduction Law, in the case of multiplicity and repetition of the crime, in which the application of the intensification of the punishment was mandatory, this amendment law to some extent removed the requirement to intensify the punishment in the situation of the multiplicity and repetition of the crime, and with some conditions The judicial authority has placed and even allowed the application of reduced punishment in cases of multiple and repeated crimes. In the criminal laws of Iran, in the spiritual multiplicity of the crime, the theory of aggravating the punishment is not accepted. According to the Supreme Court of this country, if these two definitions cannot be added together and create a violation of the interests of others, a single act can cause the realization of two or more crimes.

Bachground: Noise is one of the most important harmful factors in the environment. There are limited studies on the effect of noise loudness on brain signals and attention. The main objective of this study was to investigate the relationship between exposure to different loudness levels with brain index, types of attention, and subjective evaluation.

Four noises with different loudness levels were generated. Sixty‑four male students participated in this study. Each subject performed the integrated visual and auditory continuous performance test (IVA-2) test before and during exposure to noise loudness signals while their electroencephalography was recorded. Finally, the alpha‑to‑gamma ratio (AGR), five types of attention, and the subjective evaluation results were examined.

During exposure to loudness levels, the AGR and types of attention decreased while the NASA‑Tax Load Index (NASA‑TLX) scores increased. The noise exposure at lower loudness levels (65 and 75 phon) leads to greater attention dysfunction than at higher loudness. The AGR was significantly changed during exposure to 65 and 75 phon and audio stimuli. This significant change was observed in exposure at all loudness levels except 85 phon and visual stimuli. The divided and sustained attention changed significantly during exposure to all loudness levels and visual stimuli. The AGR had a significant inverse correlation with the total score of NASA‑TLX during noise exposure.

These results can lead to the design of methods to control the psychological effects of noise at specific frequencies (250 and 4000 Hz) and can prevent non‑auditory damage to human cognitive performance in industrial and urban environments.

Noise is one of the most important environmental stressors, which, along with the prevalence of exposure in the work and living environment, has various effects. Noise exposure can create positive or negative consequences at different levels. Based on this, in the present study, brain wave changes in exposure to different levels of noise were investigated. In this experimental study, 72 student volunteers with an average age of 26.27 years old, participated in this study after meeting the exclusion criteria and receiving sufficient training regarding the implementation procedure. Before starting the test, demographic questionnaires, noise sensitivity, and audiometry were completed for the participants. For exposure, a noise level of 45 dB was chosen as the background sound, and three levels of 75, 85, and 95 dB were selected for exposure. The participants were exposed to the determined facial pressure level for half an hour and rested for half an hour after that. During exposure to the noise, the brain waves of the volunteers were used by the portable EEG device Ewave, 16 channels. And the results were analyzed by the mat lab v12 software. The results of the study show that exposure to two levels of 75 and 85 dB of absolute power alpha has increased in 14 brain channels, including CZ and O2 channels. The results showed that the noise level of 75 dB compared to the background state did not change significantly in any of the channels (P>0.05). At the level of 85 and 95 dB, the absolute power of the beta frequency band has increased. At the level of 95 dB, this increase is statistically noticeable and significant in almost all brain regions (P<0.05). Based on the results of this study, it can be said that exposure to noise causes changes in neuronal activities in the brain, and this can affect the performance of the exposed workers.

Customer churn prediction has been gaining significant attention due to the increasing competition among mobile service providers. Machine learning algorithms are commonly used to predict churn; however, their performance can still be improved due to the complexity of customer data structure. Additionally, the lack of interpretability in their results leads to a lack of trust among managers. In this study, a step-by-step framework consisting of three layers is proposed to predict customer churn with high interpretability. The first layer utilizes data preprocessing techniques, the second layer proposes a novel classification model based on supervised and unsupervised algorithms, and the third layer uses evaluation criteria to improve interpretability. The proposed model outperforms existing models in both predictive and descriptive scores. The novelties of this paper lie in proposing a hybrid machine learning model for customer churn prediction and evaluating its interpretability using extracted indicators. Results demonstrate the superiority of clustered dataset versions of models over non-clustered versions, with KNN achieving a recall score of almost 99% for the first layer and the cluster decision tree achieving a 96% recall score for the second layer. Additionally, parameter sensitivity and stability are found to be effective interpretability evaluation metrics.

This study aims to provide a risk assessment method based on a fuzzy Bayesian network (FBN) to prevent the failure of firefighting systems (FSs).

In this research, the fault tree structure was validated, and the failure factors were identified. Triangular fuzzy numbers and the combined CoA/Sum-Product method were used to calculate the failure probability. Then, deductive and inductive reasoning and sensitivity analysis were performed using fuzzy logic and fault tree transmission in a Bayesian network (BN).

The results of a case study in methanol storage tanks showed that the combination of FBN and validation of structures can be presented as a suitable method to evaluate the reliability of FSs. The content validity index of the final basic events was over 0.79. The highest and lowest failure probabilities were related to foam system failure and valve failure, respectively. Also, the failure probability for the failure of FSs was 5.7E-6 based on a fuzzy fault tree (FFT). After updating with BN, the previous probability of failure of FSs with FBN was calculated to be 0.022978, which was greater than the value of the FFT. The reliability of the system was equal to 0.77022.

the present approach can help the decisions of managers and analysts of the petrochemical industry to prevent the failure of FSs in tanks due to changes in systems.

The growing importance of the role of banks and credit financial institutions in various aspects of economic life and the need for legal supervision and protection over them, has caused legislators to pay more attention to the rights governing their activities. Bankruptcy is one of the most important issues for banks and financial and credit institutions, which is discussed in this article.

This is a descriptive-analytical article using the library method to investigate the question.

Ethical considerations:

 In this article, the originality of the texts, honesty and trustworthiness have been observed.

In jurisprudence, bankruptcy is referred to as bankruptcy and usury, which is reflected in the discussion of bankruptcy in Iranian law. In commercial law, the bankruptcy of banks is seen as the bankruptcy of other merchants or corporations, which does not explain the bankruptcy of banks and credit institutions. Differences in the concept of bankruptcy and the goals, performance and nature of banks with commercial companies are important issues that have been overlooked. Violations of the Commercial Code in the Draft Banking Law have been largely eliminated. The bill takes a more coherent and precise approach to the bankruptcy of banks and credit financial institutions.

The draft banking law does not pay attention to international laws and therefore is not in line with the needs of international trade today.

Administrative litigation as one of the most important types of litigation in any legal system is related to individual freedoms. Thus, along with the chapter on hostility and the realization of justice, the discovery of the truth is one of the most important goals of administrative proceedings. Discovering the truth, which means the process of convincing the judge's conscience in obtaining the truth of the cases, is one of the most important challenges and issues in administrative proceedings; Because the process of discovering it is not simply possible. Accordingly, if the ultimate goal of administrative proceedings is to discover the truth, it must include characteristics and requirements. Accordingly, the judicial system with features such as the principle of publicity of the proceedings, the principle of expertise and correspondence and requirements such as the fulfillment of fair trial standards, the right to a lawyer, two-stage proceedings, results show that judges can not resort to methods that are outside the scope of the law to discover the truth. acquisition of evidence will be legitimate and lawful whenever the provisions of the law are observed and the fundamental rights and freedoms of individuals are observed in the collection of evidence, but if, in the process of obtaining evidence, legal rules are violated, obtaining evidence is illegitimate and illegal. will be. Therefore, the mere legality of the study of reason or the legitimacy of the system of legal reasons is not sufficient to be presented in court; Because the reason must be obtained legally.

The applicability of Nanofiber (NF) membranes in air sampling of pollutants for the purpose of determining the airborne concentration has received little attention around the world. The present study aims to optimize the fabrication of NF membrane for the of air sampling application.

The polyvinyl chloride NF membranes were fabricated using needle-based solution electrospinning technique. The experimental design was prepared by Design-Expert v7.0 and data analysis was done by Central Composite Design (CCD) base on Response Surface Methodology (RSM) technique. The ability of the fabricated membranes in air sampling applications was performed by sampling of airborne crystalline silica by them using the National Institute for Occupational Safety and Health (NIOSH7602) method and then comparing with the commercial PVC membranes.

The fabricated NF membranes had a mean porosity of 31.60% compared to a porosity of 25.1% in the case of commercial Polyvinyl Chloride (PVC) membranes. The electrospun NF membranes had mean pressure drop of 194.23 Pa, which is lower than the 204 Pa pressure drop of commercial PVC filters. The mean concentration of silica sampled by the electrospun NF membrane was 0.14 mg/m3 while this was 0.03 mg/m3 for commercial PVC membrane. The difference concentration of crystalline silica sampled by NF and commercial PVC membranes had the strongest relationship with the electrospinning solution concentration (r=-0.785, p>0.05).

The NF membrane has high performance in sampling the crystalline silica dust from the air stream compared to commercial PVC membranes.

Vibration, especially whole body vibration, is one of the most important physical harmful factors in industrial environments as well as vehicles. Exposure to whole-body vibration can cause different mental and physiological reactions in humans. This study aimed to investigate the effect of exposure to whole body vibration on the mental performances of 20-29 years old males in laboratory conditions.

In this research, 32 male students of Shahid Beheshti University of Medical Sciences with an average age of 22.19±2.6 years and a BMI of 20.23±2.21 kg/m2 participated. The acceleration of the whole body vibration was considered at three levels of low (0.53 m/s2), moderate (0.81 m/s2) and high (1.12 m/s2) according to the ISO 2631 standard at a frequency of 3-7 Hz. The mental functions of each subject were examined first in the vibration-free state and then at different vibration acceleration levels using the IVA (Integrated Visual and Auditory Continues) tool.  The heart rate of the subjects was also recorded by a digital heart rate monitor.

The results of this study showed that with increasing whole body vibration acceleration, visual and auditory attention decreased significantly (P<0.001). In addition, the heart rate and response time of the subjects significantly increased (P<0.001).

The results showed that whole body vibration is an effective factor in reaction time, mental functions and physiological parameters, which can reduce the accuracy of the work.

The evolution of cyberspace in recent years and its pervasive expansion and the tremendous impact this environment has on human life in a way that minimizes the boundary between real-world and cyber-life. The need to pay for new aspects of cyberspace has become inevitable. The evolution of cybercrime and the spread of organized cyber crime groups apart from its various forms make it increasingly necessary to address legal strategies to tackle this transnational criminal phenomenon. In other words, given the limitation of the scope of organized cybercrime and the interference of international organizations and governments with this type of criminal phenomenon, identifying national and transnational legislative measures and strategies against it is particularly important; It can be tackled by other cyber-attackers. Therefore, in the present study, by analyzing the strategies of the United Nations and the Council of Europe, as well as the legislative policies of some governments in the fight against organized cybercrime, and in addition to examining the legal policy of our country against such crimes, it has provided an analysis and analysis of existing strategies. It was determined, therefore, that in order to fully address and prevent organized cybercrime, we need to develop legal criminal policy and take advantage of the practices and actions of other international actors as described in this article to address the gaps and shortcomings of criminal polic to let's get rid of our legacies.

One of the most important issues regarding environmental pollution in Iranian law is the issue of balancing the expediency and responsibility of the government, because if it causes pollution and damage to the government, it will cause difficulties. Because the government structure is made up of individuals whose actions may sometimes intentionally or unintentionally cause serious pollution and damage to the environment, and since the environment has no private claimant, the compensation ratio may sometimes be neglected. As a result, the government should not be held responsible. Therefore, the interest of the government requires that the pollution caused and the damage done by the person or persons under the control of the government be compensated. So the question that will arise in this regard is how to assess the expediency and responsibility of the government in relation to environmental pollution? Therefore, according to the research question in a descriptive-analytical manner and using library tools, we came to the conclusion that in general, the government is responsible and enforces laws and regulations, but the protection of public interest is also one of the main goals and policies of the government. Sometimes it leads the government to ignore and violate the rules and regulations, in other words, the interest of society requires the government to ignore some principles and red moral and human lines in the field of environment and assign responsibility to the government.

The application of particles’ electrical mobility in the electric field has always been an important concern, as the functional basis of a number of particle measuring and classification instrumentations. The objective of this study was to design and construct an aerosol particles classification system using electrical mobility feature in laboratory scale.

This laboratory experimental study was carried out in collaboration with the Atomic Energy Organization of Iran and Shahid Beheshti University of Medical Sciences. The theoretical principles governing the development of the DMAs, the FORTRAN programming software and the Excel-2016 program were used in design and construction of the DMA system. The technical drawings of the constituent parts of the DMA and laboratory layout were carried out using SOLIDWORKS-2017 software. The laboratory instrumentation including the particle generator, particle counter, dry and clean air supply system and high voltage power supply were prepared in order to study the performance of the DMA system.

The length of classification area, the diameter of the central and outer electrodes were 160, 20 and 55 mm, respectively. The efficiency of the proposed DMA in particle classification was in the range of 71.9 - 92.4 % for particles in the range of 500 - 600 nm and 300 - 350 nm, respectively. Each range of particle size leave the equipment with maximum efficiency at a specific voltage.

By knowing the peak voltage for a particular particle size, the size distribution of the unknown particles can be determined by this device. The good performance and wide range of particle size distribution are the capabilities of the proposed DMA in this study.