حسین وحیدی

Organizing the collection of valuable recyclable waste at the city level has always been a major challenge for municipalities due to unprincipled activities. So far, various attempts have been made to organize these people in Iran, but all of them have failed. Almost all municipalities have accepted the presence of these people as an informal part of urban waste management. The purpose of this study is to create a new financial structure in the form of an activity license and investigate the informal flow of waste collectors in three scenarios by the causal loop diagram of the waste management cycle in Vensim software. The causal loop model obtained in this research brings a new and complete understanding of stakeholders, effective variables in cooperation, and competition between formal and informal actors in the waste management cycle of Kerman City.

To simulate the performance of different financial license pricing scenarios, the concepts of simulation of system thinking, dynamic planning, and CLD model have been used in Vensim software. At first, the CLD model of the waste cycle in Kerman City was drawn and analyzed using local conditions, the infrastructures of Kerman Municipality, and the behavior of actors in collecting recyclable waste. The drawing model was developed in Vensim software based on the collected field data and statistics from 2021 to 2022. The new scenario was defined based on the use of financial licenses to organize the informal collectors of recycled waste and separation from the origin of the definition and the assumptions of the model. Three scenarios of the existing situation, the basic license price of 500000 and 1000000 Tomans were examined and compared with each other.

  According to the results, in scenario 2, the municipality's share of the recycling market has increased by about 204%, and the amount of the municipality's profit, including the amount of the license issuance along with the discount, has increased by 232%. In scenario 3, the municipality's share of the recycling market has increased by about 400% compared to the current situation, and compared to the second scenario, it has increased by 64%, and the amount of the municipality's profit has increased by 507% compared to the current situation.

Financial licenses in the field of municipal waste management have been used in their simplest form so far, which have been mostly ineffective. The use of smart financial and licensing systems based on field conditions, the dynamics of actors' behavior, and smart policies can be a suitable solution for organizing urban waste management, especially the informal waste collection fleet.

The world around us is always changing. The process of these changes is focused on the fourth industrial revolution (industry 4/0). These changes will definitely affect the entire society and as a result the educational needs and teaching/learning methods will also change. The purpose of this article is to identify and classify the implementation requirements of the fourth generation education, which was done by using the mixed research method (qualitative-quantitative). The research is in terms of developmental and practical purpose, in terms of descriptive-survey nature, purposeful sampling method and library and field data collection method. The statistical population of the research includes experts in the fields of management and industrial engineering, educational management and curriculum planning. First, by analyzing the texts regarding the education of the fourth generation, 42 basic themes were identified and classified into 7 organizing themes and 2 comprehensive themes. Then, based on the extracted basic themes, we compiled a questionnaire containing 42 questions and provided it to the experts. After the answers of 21 experts, the results were ranked in the SPSS25 software by Friedman test, which shows that the three basic themes are low delay and high data rate, acceptance educational software are the most necessary basic topics for implementing 4/0 education.

Waste management has always been a significant challenge for municipalities. Alongside the formal operational cycle of municipalities, other stakeholders and actors also play an informal role in urban waste management. The majority of the segregation of valuable waste is carried out by these individuals. This study presents the waste management of the city of Kerman, focusing on both formal and informal recycling collection cycles and utilizing financial permits and municipal oversight to regulate these activities.

In this study, the waste management cycle model of the city of Kerman is initially introduced, emphasizing the formal and informal recycling collection cycles. Subsequently, a simulated model in MATLAB software is presented, along with a fuzzy controller system for determining the purchase price of recyclable materials by the municipality to compete with the informal cycle.

The model's results, including the number of individuals attracted by the formal network, the municipality's revenue from the purchase and sale of recyclables, and the sale of permits for a scenario with a permit price equivalent to ten million Rials, were examined. According to the results, the existence of an activity permit tool significantly impacts the municipality's share in attracting the participation of informal collectors throughout the city.

To prevent protests and a lack of support for the plan, it is recommended that the permit price be lower at the initial implementation stage, and the intensity of oversight be increased as much as possible to ensure collectors are required to obtain an activity permit. Issuing activity permits can not only enhance the financial benefits for the municipality but also have positive social and environmental effects, improving the supervision of individuals' activities.

Leachate from waste disposal is recognized as one of the primary sources of groundwater contamination. Therefore, improving the management of landfill sites is crucial for reducing and controlling environmental threats. This study focuses on modeling the dispersion of leachate in a landfill in the city of Isfahan using the finite element method, located 35 kilometers outside the city. The leachate is considered in this area with dimensions of 100 by 250 meters and a depth of 2 centimeters from the bottom. The transmission and spread of pollution across twenty sub-layers of soil have been modeled using Richards' equations and pollution transport equations in porous media. This research utilizes COMSOL software to merge different environments using two model equations, and the three-dimensional model investigates the movement and absorption of leachate based on these equations. Meshing in the landfill is done finer in the upper and bottom layers where leachate leakage exists and coarser in the lower parts. Also, mesh modeling in the software is done freely and in a hexagonal shape. According to the findings, the soil under the landfill becomes saturated over time, with the saturation occurring faster in the upper layers. Modeling results show that phosphorus metal pollution has penetrated up to a depth of 1.8 meters in the soil over 15 years, and leachate has reached approximately 10 meters deep into the ground. Given the proximity of groundwater to the soil surface, measures such as pumping wells and geomembranes must be considered to prevent pollution from entering the groundwater.

Today, the efficient sharing of knowledge increases the chances of survival of organizations and is considered as a strategic resource for improving the productivity of organizations. The purpose of this research is to identify knowledge sharing mindsets among generation Z employees in a defense research training center in Malik Ashtar University of Technology. The current research is cross-sectional in terms of practical purpose, in terms of descriptive method, in terms of quantitative and qualitative (mixed) data collection, and in terms of time horizon, and as far as the researchers have investigated, no research with this title has been conducted. The statistical population of the research consisted of 20 employees of generation Z (born in 1373 and later) and several university faculty members who were selected purposefully. Q methodology has been used to analyze the collected statistical data. In this research, after reviewing the subject literature and conducting interviews with several university experts, different propositions regarding the research topic (36 indicators) were identified and extracted. Then the questionnaires were completed by 20 participants in the research and the collected data were analyzed by exploratory factor analysis. Seven different mentalities and viewpoints with the names of good sense of knowledge sharing, knowledge-oriented leadership, teamwork, reward system, perception of relative benefits, job satisfaction and organizational commitment were discovered and identified, which explain and cover 77% of the total variance.

The relatively high rate of failure in the implementation of the organization's strategies, the comprehensive understanding of the factors affecting the successful implementation of strategies is of particular importance. despite the importance of this issue, so far there is no comprehensive research on the explanation of the factors and components affecting the success of the Strategies implementation have not been implemented.
The purpose of this research is to comprehensively identify and categorize the factors affecting the successful implementation of strategies in Iranian organizations based on previous studies in this field.
This study used qualitative method and for data collection , articles has been used and in terms of purpose this research is practical. in this study based on the searches made among Iranian article databases and internet sources between 2013 and 2023.At the First, 108 articles related to the topic of discovery were gathered and finally 21 articles were evaluated using the meta- synthesis qualitative analysis method and inclusion criteria.
Based on the 7-step method of Barroso and Sandelowski and the open coding method, 45 factors were identified and extracted, and in 5 components distributed : planning and management (18 codes), infrastructure and structure (5 codes), human resources. (13 codes), organizational culture (4 codes) and financial and credit component (5 codes) were categorized.
Among the final articles, the factor of organizational culture had the most repetition and factors such as strategic budgeting fit, vertical alignment of strategies, etc. had the least repetition among the studied articles

There is a direct relationship between the number of machinery in any industrial problem, their costs of purchase,  and the space they occupy. Accordingly, due considerations about the constraints are required in space and budget. Workshop production problems under uncertainty conditions including more than two pieces of machinery are regarded as NP-hard. Therefore, using common research in operation techniques, one cannot embark upon modelling and finding the optimal answer for such problems. Hence, this study aims to propose a conceptual mathematical model for the problem of industrial production. The research problem involves cost limitations while working out the solution through simulation studies.

Design/methodology/approach: 

First a mathematical model has been proposed for workshop production with cost and space constraints. Then by enlisting the help of Arena software, 14 simulation models have been designed for machine ‘m’ and work ‘n’ of different production sequences. Finally, by solving a numerical model example, the problem of nearing the optimal condition of the problem, considering minimizing the objective function of the tardiness and earliness costs, has been resolved. This measure has been adopted to determine the optimal number of machinery, considering work prioritization laws in work cells by executing the model and scatter search algorithm and designing relevant experiments.

Solving a numerical example considering the default number of machinery and the LPT optimization method resulted in the best answer when the total tardiness and earliness costs were intended. In contrast, in the case of increasing the number of machineries, both the LPT (longest process time) and CR (critical ratio) methods led to the best answers with the help of dispersed search algorithms in simulation studies. The results included the cost and space constraints.

Research implications:

 One of the prominent features of simulation is that with the minimum distance between the problem and the real world (not removing the limitations and complexities for solving the problem, which is usually done by removing the facts in other problem-solving methods, to reduce the complexity and the possibility of solving the problem) problem-solving and decision-making scenarios are applied. This helps managers in decision-making. Most of the time, the physical study of systems is very difficult and costly, or even impossible; therefore, an alternative model should be used to study the system.

Originality/value: 

A careful investigation of previous research and relevant literature reveals that none of the studies in the literature have simultaneously dealt with the problem of the number of machinery in conditions of cost and space limitations. Therefore, the present study incorporated the mentioned constraints in the scheduling problems and adopted simulation problem-solving methods. It resulted in delving and enriching the subject further.

The integration of advanced technologies, such as smart automation systems and the Internet of Things (IoT), has revolutionized modern greenhouses by enhancing product quality, precise plant growth control, disease and pest reduction, chemical and toxin minimization, waste reduction, and overall operational efficiency. This study focuses on the development of a wireless configuration to transform conventional greenhouses into smart ones with minimal expenses and modifications. The proposed system employs a comprehensive range of sensors to monitor crucial environmental parameters, including temperature, air humidity, light intensity, soil moisture, and CO2 concentration. WiFi and ZigBee protocols are evaluated to establish seamless communication between these sensors and the central monitoring station. WiFi protocol is deemed cost-effective in greenhouses where no interference occurs within the 2.4 GHz frequency range. However, in cases where frequency interference is present, utilizing ZigBee modules operating at sub-one gigahertz frequency (900 MHz) or using the WiFi in the 5 GHz band is recommended. This wireless configuration minimizes installation and setup time and costs and enables remote monitoring and control of greenhouse conditions, empowering users with real-time access to intelligent control system information anytime and anywhere. The proposed solution contributes to the advancement of smart greenhouse automation, offering an economical and efficient approach for the widespread adoption of intelligent systems in the agricultural sector.

The development of the necessary infrastructure to enhance the walkability in urban areas has an important role in sustainable urban development and from various aspects of the environment, public health and social justice can improve the quality of life. This study aimed to investigate the pedestrian capability approach for the development of a sustainable city in District 16 of Tehran Municipality as one of the greenest urban areas in Tehran.

In this research, the criteria, qualities, characteristics and physical, functional and spatial variables of the man-made environment that affect the amount of walking in the D16 of Tehran Municipality have been studied and collected. Then, using GIS spatial analysis and prioritization of indicators using Analytical Hierarchical Process, the pedestrianization of different parts of the region has been investigated.

Criteria affecting the location of sidewalks and greenways in the D16 in 9 main categories and 30 sub-criteria were collected in a hierarchical structure and their spatial information was collected. The diversity and wide range of indicators evaluated results in a comprehensive analysis of the current situation can be considered as one of the strengths of this study. Each of these indicators was analyzed for the study area and the situation of walking potential in the D16 was studied based on each of the indicators. Using the preference of criteria based on the opinion of experts and the overlap of different layers, finally, the map of the degree of walkability and the map of the degree of the walkability of the road network in the 16th district of Tehran Municipality was obtained. According to the results, the spatial value shows the highest values ​​in Khazaneh, Naziabad and Bagh Azari neighborhoods, respectively. In addition, Bukharai Street, Madaen Street, Rajaei Street and Street next to Besat Park are the axes with the highest amount of pedestrian traffic in the region, respectively.

Based on detailed traffic studies, the best places to define sidewalks or urban greenways were identified, and since these axes have a high volume of pedestrian traffic, it is very important to pay attention to the needs of pedestrians in them. The three neighborhoods of Naziabad, Aliabad North and Khazaneh were identified as three suitable areas for the development of pedestrian axes in the region and were introduced to further concentrate the municipality of the region.

Using waste as a source of energy production is one of the appropriate solutions for the sustainable development of urban waste management. Biomass sources are superior to other renewable sources because they are easily converted into solid fuels, liquids and useful gases. One of these resources, which has caused a great deal of concern in large cities today, is municipal waste, which is one of the main policies of the relevant organizations in determining the best solution for its management. One of the most important solutions that can be introduced in this direction is the use of technologies that can convert a large part of waste into very valuable biofuels that are a good alternative to fossil fuels. There are various types of these technologies, including incinerators, anaerobic digestion, SRF fuels, and pyrolysis. In this project, the main purpose is to study the use of municipal waste according to the concept of zero waste (Zero Waste) and to know the exact types of technologies for the conversion of municipal waste into biofuels. The analysis method used in this research is AHP method. The result of hierarchical analysis shows that the SRF fuel technology method and use in the cement plant furnace for organic waste management is the first priority in Kerman. The result of hierarchical method analysis using Expert Choice software was also confirmed.

Due to population growth and industrial progress, the only important issue isn`t the lack of water resources, but besides that, the issues of runoff management, its quality, and urban wastewater management are also important. In this research, Khoorsuzan estuary located in Bandar Abbas city, Hormozgan province, was studied in terms of water quality. SWMM rainfall-runoff dynamic model was used for quality modeling of regional runoff. Hydraulic modeling was done for four precipitation events. The results of the sensitivity analysis showed that three parameters, percentage of impermeability of sub-basins, curve number and channel roughness coefficient, were the most effective parameters, respectively. Calibration and verification were done based on the objective functions of MRE and N.S. Its results were within the very good range of matching the model with the observational data for four times. Finally, qualitative modeling was done for four target pollutants, including COD, TDS, NO2 and PO4, and the qualitative results showed that the model was in good agreement with the observational laboratory data. At the end, three scenarios were considered to solve the problem. The first scenario showed the reduction of TDS pollutant concentration up to 84.52%. The results of the second scenario for COD, NO2 and PO4 pollutants reduced up to 100% and the application of the third scenario effectively reduced TDS, PO4, COD and NO2 pollutants. Based on the results of this research, the amount of water pollution around Khoorsuzan without wastewater management is more than the standard and the runoff from rainfall does not help to reduce pollution.

Understanding what obstacles are in the direction of knowledge management is essential, despite the importance of this issue, a comprehensive study has not been conducted so far. The purpose of this study is to identify and categorize the challenges facing Iranian organizations for implementing knowledge management based on the study of previous research between 2011 to 2021 by ultra combination Method. In the present study, the 7-step method of Sandluski and Baruosu has been used. For this purpose, searching, and identifying research -related research through the library search system on websites such as Academic Jihad, Islamic Computer Science Research Center, Scientific Articles of Country Provision, Iranian Magazines, and Net Science were studied, and 188 relevant articles were then extracted, then Based on the title, abstract and text of related research, prioritization and elimination of unwanted or less related cases were discussed and finally 31 final articles were selected. The data analysis method is based on open coding and the results of the study include 59 codes (challenge) below 4 main components: managerial and structural factors (28 codes), executive factors (17 code), cultural factors (10 codes) and technology and infrastructure factors (4 code) were categorized.

Green management is one of the key factors for sustainable development and improvement of organizational performance level. The development of university waste management with a green management approach can help to improve the environmental status and quality of university sustainability indicators. This study attempts to document the status of waste management elements at the Kerman Graduate University of Technologies as a sample of Iranian universities and prioritize the factors and practical suggestions due to the finance, man power and time effectiveness. For this purpose, by visiting various units such as office, educational, facilities, laboratories, student dormitories, cafe and kitchen, the status of waste management elements was evaluated. In order to evaluate the priority of indicators affecting the required elements of waste management in universities, using Analytical Hierarchy Process and paired comparisons techniques are proposed to classify, prioritize and initiate future actions in three categories of educational, executive and Management was discussed. In short, locating and setting up a special waste disposal site and conducting its executive planning, as well as training courses for students and staff are among the most important measures to begin improving waste management at the university.

population growth and pollutions from sewage discharged of various land uses have resulted in expansion of pollution and water resource constraints. One of the simplest ways to determine qualitative condition of water is using water qualitative indicators that could be used as a decision making tool by managers and experts. NSF is a comprehensive index and efficient tool to determine water quality and classify water resources based on quality; and, it is more applicable than other qualitative indicators of water. The study deals with qualitative review of Kangir River in Ilam Province, through NSFWQI indicator. Qualitative and quantitative data required including those related to the river during two dry and wet seasons have been obtained for 5 stations, from Department of Environment and Regional Water Company in Ilam. Results obtained from the indicator showed that water qualities of river in all points are classified as average and low. Highest indicator value (66) has been related to first station (December 22nd- January 20the); and, lowest value has been related to second station (30) and during Tir and Shahrivar months (June 22nd-July 22nd and August 23rd-September 22nd), after sewage discharge. Throughout the river, quality of water takes an improvement trend so that in last station and near Kangir Dam, again quality of water goes back to average, Which indicates the ability of the river to self-purify. Main reason for reduction of NSF indicator is discharge of non-treated sewage and high value of such parameters as BOD and coliforms, in addition to reduction of DO. In addition to usage made of qualitative indicators, to determine expected reaction of river caused by pollutants, mathematical models have to be used. In present study and to simulate pH, BOD, dissolved oxygen, temperature, and coliform, QUAL2KW model has been used which makes a single dimension simulation of the river, along with non-uniform steady flow. Day and Mordad months (December 22nd- January 20th and August 23rd-September 22nd) have been selected as wet and dry periods of the year; and, the model has been calibrated for each period, separately. Then, 50% reduction scenario in coliform and BOD from point resource of pollution has been implemented for the model under fixed temperature and flow rate. It was shown that NSFWQI indicator would be increased in stations, if the scenario would be performed; and, the increase depends on taking effect from point resources of pollution. Maximum increase of NSFWQI index for Alamdar station (after discharging municipal sewage) by an average of 10 And the minimum increase in the index for the Kapne kran station (last station) will be an average of 2.

In today’s competitive world, the ability of acceptance and utilization of ICT in industries is one of the critical success factors in productive industries. The target of this paper is presentation of a model for evaluation of e-manufacturing e-readiness in manufacturing industries. This research was conducted in three phases utilizing mixed research method. In the first phase, Barroso and Sandelowski Meta-Synthesis method containing seven steps was invoked and the primary conceptual model was created. In the second phase, by arranging semi-structured interviews with the experts, a supplementary model was completed. In the third phase in order to quantitatively validate the developed model, various statistical tests and confirmatory factor analysis were employed. Structural equation modeling and path analysis were made use of for checking accuracy of the assumptions as well as testing the proposed model in SmartPLS 3 software. After confirmation of path coefficients and coefficients meaningfulness (t-values), we checked model in terms of various indexes, all of which point to the eminence of the model. The results of applying the above steps were corroboration of the scientific standing of the latter model. Incorporating there major components i.e. , ICT infrastructure in manufacturing , ICT application capacities in manufacturing, ICT value augmenting opportunities in manufacturing along with 28 indexes, the model set forth in this study was ultimately received full confirmation.

In the past three decades, technical and professional educations have been promoted in the developing countries and focus of engineering educations have been based on new pioneer technologies. The target of this paper is presentation of framework for exploration of e-manufacturing components for engineer's education. This research is done considering mixed research method in 3 phases. In the first phase the 7 steps method of Barroso and Sndlvsky meta-synthesis was used and primary conceptual framework was created. Then in the second phase by semi-structured interviewing with experts, supplementary model was concluded. In the third phase, in order for quantitative validation of the proposed framework, various statistical tests and confirmatory factor analysis have been used. Also structural equation modeling and path analysis for checking accuracy of assumptions is used. Testing model is carried via SmartPLS 3 software and after confirmation of path coefficients and meaningful coefficient (t-values), the model is checked with Cv-Red and Cv-Com indexes. Results of test indexes showed suitability of the proposed framework. Furhter results of the mentioned steps emphasized the scientific validity of research framework, thus research framework with 2 key components of (Management educations and Technology educations) and 8 sub components( EMS , SCM , CRM , E-Diagnostics , E-Maintenance , E-Commerce , New communication technology and Advanced manufacturing technologies) were confirmed .

High concentrations of antibiotics are now detected in aquatic environments, reducing their quality. These compounds generally have a high toxicity and low biodegradability, and some are reported to have mutagenic and/or carcinogenic characteristics. Conventional treatment systems have proven inadequate to effectively remove this type of organic compound, largely due to its complex molecular structure. Therefore, it is necessary to remove an effective method for the removal of these compounds is suggested. The purpose of this study was to apply zero-valent iron nanoparticles in the presence of hydrogen peroxide and the process of sonolysis in the removal of antibiotic amoxicillin from aquatic environments.
This research was carried out on a laboratory scale on a synthetic wastewater containing amoxicillin antibiotic that the effects of some parameters, such as ultrasound (35 and 130 kHz), contact time (30–150 min), concentration of hydrogen peroxide (0.5–3 %), concentrations of nZVI (0.06–0.2 g/L), pH (3–10), and concentration of AMX (45–100 mg/L) were investigated.
Optimum removal conditions were pH = 3, H2O2 concentration= 1%, ultrasonic frequency= 130 kHz and nZVI concentration= 0.2 g/L. so that 97.3% of amoxicillin antibiotic after 150 min of reaction at pH=3, nZVI= 0.1 g/L, ultrasonic frequency= 130 kH, H2O2 =1% and 45 mg/L concentration of AMX was removed.
The experiments showed the efficient removal of amoxicillin antibiotic in wastewater by Fenton’s oxidation process. The efficiency of this method can also be considered in eliminating other antibiotics resistant to biological treatment.

A modern economy is knowledge-based economy in which the production, distribution and use of knowledge is the main source of growth and wealth creation. Knowledge-based companies are the engine of this system. This study was conducted to survey of factors affecting the development of these companies. For this purpose, surveys of target groups, including corporate executives and experts from the Ministry of Health is done and to rate the Analytic Hierarchy Process is used. AHP technique is widely used in various fields such as multi-criteria decision assessment, planning, decision-making and forecasting has been used. For this purpose, eight important factors have been investigated, include technological factors, social, market conditions, political, administrative, economic, legal and environmental and compared comments of two groups. As is clear from the results, All factors (technology, management, marketing, economics, law, politics, society and environment) in terms of both the target group had effect on the development of knowledge-based companies. Indicators of technology, economics and law (in order of preference) from the perspective of firm managers are three major factors affecting. Standards of environmental, social and policy choices are at least important. The ministry experts have considered issues of management as key factor.

There are always Interaction relationships between the sponsors and the sport teams. This relationship leads to many advantages such as the sport teams need to increase their finances whereas the sponsors want to use the broadcast and the advertisement. It should be noted that there is a significant issue that is the sponsors should focus on what criteria and what are the priorities of the criteria to choose their teams.
Analysis Hierarchical Process technique is used as the Multi criteria decision method. Therefore, 14 indicators are selected and categorized in three factors including the team, national and economic criteria. The pair-wise comparisons are conducted and their weights are calculated. 26 questionnaires were gathered and finally the average scores were used in the AHP model.
The condition of team allocates the most criteria which is logical due to the exchange rules. Moreover, the weight of economic criteria is more than the others which is acceptable due to the current national economic conditions. Finally, all the criteria are discussed and the priority of each is calculated. It should be mentioned the inconsistency ratio of the model is very low which shows the high accuracy of the judgments.
Due to factors such as the appropriateness of the research funding, financial commitment and support to the team (0.144, 0.141) and the team's performance (0.126) in the first three indicators in deciding and choosing the sponsors of our were countries. This can serve as an effective factor in recruitment and selection are introduced and sponsored.

Nowadays, in developing and under developing countries industries are developed rapidly. Ghathering various industries in one place has significant advantages such as better management, establishing essential foundations with lower costs, controlling the environmental pollutions and creating more competitions. On the other hand, the disadvantaged are generating various wastes in the high volumes. Therefore, the quantity and the quality of the Charmshahr & Salariyeh industrial state are assessed. This state has more than 200 active factories which lead to generate more than 21 thousand tons per year. Hence, AHP technique with the application of TBL method is conducted to choose the most proper solid waste management system for the state. Moreover, the sensitive analysis is conducted too. At end, recycling with the final weight of 0,325 is selected as the most proper scenario and incineration stands at the second place with the weight of 0.243. However, composting and landfilling are chosen as the next strategies with the weights of 0.238 and 0.194, respectively.