Environmental Sciences
Year:2019 | Volume:16 | Issue:4 |Papers Count:18

Introduction: In recent decades, the growth of environmental pollution has led to the emergence of a new type of consumer called the green consumer. They regard themselves as responsible for the environment and use products with less damage to the environment. By recognizing these consumers, companies are putting more effort to make their business greener to achieve this market segment. Therefore, identifying the factors that influence the selection of green products and services is important. Since the values of individuals, as an important social phenomenon, is influential in shaping, controlling and predicting their behavior, they can affect the green consumption behavior. Therefore, the purpose of this study is to investigate the relationship between each ethical value and the green consumption behavior. Material and methods: This is an applied research that uses fundamental research findings to identify and solve various problems. In addition, a survey was carried out. The statistical population of this study included 17067 students studying at Shahid Beheshti University from all faculties and educational levels in 2017. The convenience sampling method was used for sampling. According to the sample size table, 375 people were selected and 353 questionnaires were analyzed. In order to evaluate the students' values, Schwartz Personal Values Questionnaire was used. The reliability of the test was estimated at 0. 893 by calculating the Cronbach's alpha coefficient. In order to measure the green consumption, five questions were used, the validity and reliability of which were acceptable. In order to analyze the findings, descriptive and inferential statistical methods were carried out by SPSS software. Results and discussion: Comparison of descriptive statistics showed that the reason why people used green cars was easy transportation to the university (37. 7%), helping to improve the environment (36. 3%), reasonable prices (14. 2%) and to diversify their trips (10. 8%). The relation between the use of green cars for helping to improve the environment with each of Schwartz's ethical values and the relationship between the preference of using green products with these values showed that the correlation coefficient between the preferences of using green products and the excitement value is r=-0. 114, which is significant at the level of 0. 01. In other words, there is a significant and negative relationship between the use of green products and the excitement value. However, there was not a significant relationship between the use of green products and other values. Also, there is a significant relation between using green products to help the environment (green consumption) and the universalism value (p <0. 01, r = 0. 145). There was no significant relationship between using green products to help the environment and other values. Conclusion: The results showed that not all of the Schwartz values in green consumers are equally important. The existence of individual differences justifies the individual's tendency to use green products. These findings can be applied to environmental practitioners, especially educators and marketers.

Introduction: Global warming is increasingly affecting the ecological balance of the planet. Nowadays, human activities, especially agricultural productions, are thought to be mainly responsible for this phenomenon, as they have led to increasing concentrations of greenhouse gases (GHG) in the atmosphere. Therefore, the present study investigated the relationship between agricultural production and the environment in developing-8 (D-8) countries. To this end, the area of arable land and livestock production index were used as agricultural sector production indices and the ecological footprint (EF) indicator was used as an environmental index. Material and methods: A panel model for studying the agricultural production– environment was established. Also, the estimation of this relationship was conducted for all D-8 countries from 1990 to 2013. According to panel unit root tests and panel cointegration tests, the short and long-run relationships were estimated by Error Correction Model (ECM) and Fully Modified Ordinary Least Square (FMOLS), respectively. Results and discussion: The empirical results revealed that the relationship between EF and per capita Gross Domestic Production (GDP) was N-shaped and statistically significant. Moreover, the results imply that a relative increase in energy consumption, arable land, and livestock production had a positive effect on the EF. Evidence from the study showed that a 10% increase in crop production land will increase EF by 2. 15%, while a 10% increase in the livestock production index will increase EF by 1. 18% in the long-run. Furthermore, a 10% increase in energy consumption will increase EF by 7. 38%. Conclusion: The main finding of this study was that agricultural activities are one of the most important environmental pollutants and have a significant effect on EF in D-8 countries. In addition, crop production has a larger effect on EF compare than livestock production in the long-run.

Introduction: Land use has always been one of the most important indications of the adverse impact of mankind on their environment. It is an activity that human beings, through using natural resources, contribute to their socio-economic development and at the same time, alter the processes and structures within the environment. One of the most important sources that have been damaged during the past decades through land use change is water resources, especially groundwater. Considering the importance of groundwater resources in supplying drinking water and agriculture, qualitative monitoring and spatial and temporal distribution of the process of its changes are important issues in planning and managing water resources. Therefore, the present research investigates the effects of changing the use of groundwater quality in Kerman Plain. Material and methods: Land maps of Landsat 5, 7 and 8 were used for land use mapping in Kerman Plain. These are TM (1987), ETM + (2002) and OLI (2017) sensors, respectively. Also, in order to investigate the process of qualitative changes of groundwater resources in Kerman Plain, statistical data and information of 2002 and 2017 were used. Then, the maps of quality parameters were mapped to the ArcGIS 9. 3 environment. Afterward, these maps were zoned to agricultural classes using Wilcox classification and the critical and contaminated areas were identified. . Spatial zonation maps of groundwater parameters for agricultural purposes were plotted based on Wilcox method. Finally, by coating the SAR and EC layers with ArcGIS9. 3 software, the water quality status of the region for agricultural use according to Wilcox classification in 1996 and 2014 the area of each group was calculated. Results and discussion: Using satellite images of the studied area, it was divided into three user units. These units included residential areas, agricultural lands, and rangelands. The quality of agricultural water was obtained from a diagram called the Wilcox Diagram. Land use change showed that a decrease has occurred in the pasture user's class. In the course of 30 years, while 1. 691 km2 of rangelands have been decreased, the area of agricultural land and residential areas has been increased. The increase was far more in residential areas than agricultural lands. Conclusion: According to the Wilcox classification, the EC and SAR parameters were increased during this period, but the trend of increase in the EC parameter was higher. For the EC parameter, almost the majority of the region had a high level of this element, which is more intense in the western parts of the region than in other regions and has been increasing over time. For the SAR element, studies have shown that the amount of this element was in the good class in all areas of the region in 2002, except for the western parts of the study area which were in the middle class in 2014.

Introduction: The mugger crocodile is one of the most vulnerable species in the recent IUCN Red list classification. Most of the populations of the species are in decline and extirpation due to the threats caused by human activities. Nowadays, species distribution modeling plays an essential role in their conservational biology and ecological studies. However, considering the lack of such data on the mugger crocodile in Iran, this study was conducted to evaluate the suitability of the crocodile habitats in the country. Material and methods: The watersheds of the Sarbaz and Kaju rivers in the Makran area are the westernmost part of the distribution range of the mugger crocodile, located in the southern part of Sistan and Baluchestan Province. Modeling the suitability of the crocodile habitats in this area was conducted using maximum entropy. The environmental variables of elevation, Normalized Difference Vegetation Index (NDVI), temperature, rainfall, and the distance from urban and rural settlements, roads, and rivers were included in the study. To eliminate high correlation variables (<0. 70), Pearson correlation test was used. By using Moran’ s I, the lack of spatial autocorrelation between the presence data of the species was assured. Sensitivity and evaluation of the relative importance of each variable were done by the percent contribution and permutation importance of each variable. Also, the response curves of the variables and the jackknife test were calculated. Maximum training sensitivity plus specificity (MTSS) and equal training sensitivity and specificity (ETSS) were used as thresholds to classify the suitable regions. Results and discussion: The amount of AUC was more than 0. 8, indicating excellent performance of the model. Based on the percent of contribution and permutation importance of each variable and the results of the jackknife test, the distance from the rivers, temperature and elevation were the most important variables. The threshold values of ETSS and MTSS were 0. 52 and 0. 18, respectively. According to the thresholds, the suitability of the habitat was classified into two suitable and unsuitable classes with an area of 312 and 1629 km2, respectively. Comparison of the thresholds in classification showed that ETSS is more accurate. Considering that the major part of the suitable habitats is located outside of the Gandou Protected Area, revision of the borders of the protected area is proposed as a suggestion for management for the conservation of this species. The study of the effect of dams on the crocodile habitat suitability in the area showed that dams increased the habitat suitability, but their negative impacts, like the loss of nesting sites, should be noted. Also, the fragmentation of the suitable habitats was obvious in the study, and considering the migration behavior of the species, corridors should also be included in conservation plans. Conclusion: Distance from the river, as the main variable determining the suitability of the mugger crocodile habitat, is affected by climatic fluctuations and the water amount. Conflicts between the crocodiles and local people for resources (water and food) as well as the immigration of crocodiles between separate habitat patches would be more severe in the warm seasons and drought situations. Therefore, in addition to revising the area of the protected area and conservation of the habitats, increasing species monitoring, public education and participation of local communities in the conservation actions would be essential.

Introduction: In recent decades, xylene has been considered as one of the most important pollutants in soil, along with other aromatic compounds in crude oil and other petrochemicals. Therefore, the aim of this study was to find bacteria for the biodegradation of this compound and to increase the degradation efficiency of this compound with the help of immobilizing the bacterium on compounds with a nanostructure such as graphene oxide. Material and methods: In the current study, biodegradation of xylene by free and immobilized bacteria on graphene oxide was studied under optimized conditions. Isolated xylene degrading bacteria from contaminated soils were identified based on 16S rDNA gene sequencing and submitted to gene bank as Sphingomonas paucimobilis strain TY4-HX. Using response surface methodology, optimum values of pH, temperature and xylene concentration for xylene degradation by free and immobilized cells were determined as 7, 32º C and 1. 5g/l, respectively. Results and discussion: Free bacterial cells were able to degrade 45. 8% of the xylene after 24h under optimized conditions. Analyzes by Fourier-transform infrared spectroscopy (FTIR) and Scanning Electron Microscope (SEM) showed that the strain adhered onto the Graphene oxide surface and developed a biofilm. Immobilized cells were able to degrade up to 86. 3% of the xylene after 24h under optimized conditions. Conclusion: Our results indicated that free and immobilized Bacteria had a suitable application potential in the treatment of xylene-containing soils.

Introduction: Rice husk production is about 482 million tons per yer all over the world. The compounds of the rice husk can be divided into organic and inorganic parts. The organic part contains cellulose, hemicellulose, and lignin and its mineral part consists of silica and metal oxides. One of the most abundant ingredients in the rice husk is silica. Twenty percent of the rice husk is white ash, which is obtained after complete burning of the rice husk in controlled time and temperatures and is a rich source of silica (more than 90 percent). In other countries, this type of recycled silica has many applications ranging from cosmetics to electronic industries, yet in Iran, recycling of silica does not happen. The aim of this work is silica production from rice husk, which is used as packing material in high-performance liquid chromatography (HPLC) column. As a result, this recycled silica from the rice husk is considered as valuable and cost-effective silica. Material and methods: For the synthesis of spherical porous silica gel from the rice husk, the physical preparation of the husk was done by burning and acidifying, adjusting the pH, and then heating (burning) at high temperatures to obtain a white powder. Then, in the alkaline conditions, the powder was converted into sodium silicate solution. Spherical porous silica gel was produced by the sol-gel method. HPLC columns were prepared by filling the column with bare silica and in the next step, silica was coated by vancomycin. Bare silica column was used for flavonoids analysis and vancomycin coated silica was tested for propranolol analysis. Results and discussion: The results obtained from the separation of flavonoids and propranolol showed that the prepared silica could be a very suitable substrate for the settlement of functional groups. Therefore, the recycling was done successfully and can be used as a column stationary phase. Conclusion: Our country is one of the largest rice producers. Rice husk silica sources (such as mineral silica) can be recycled, purified, and can have various applications such as chromatography stationary phases.

Introduction: Encouraging higher-education students, as ambassadors of environmental activities within their homes, to increase their participation in waste segregation of recyclables, can provide a clear perspective for the proper management of wastes in the country. Most of the previous studies on identifying the factors affecting public participation rate in the segregation of wastes have focused on urban areas (and not on educational environments such as universities), and the effects of the interaction of various factors on the results have not been considered. Accordingly, in this research, the level of knowledge, type of attitude, and methods of increasing the participation rate of students in waste segregation have been investigated in the Nazlou campus of Urmia University. Material and methods: A total of 113 questionnaires containing 11 multi-part questions were randomly distributed among the students (face to face interview) and the results were analyzed by SPSS software. The validity of the mentioned questionnaire was assessed by the face validity technique and its reliability was evaluated based on Cronbach's Alpha Coefficient (i. e., 0. 884). For descriptive purposes, frequency distribution tables were used. For inferential purposes, the relationship between the variables of each hypothesis was obtained by Chi-square test. Furthermore, using Kramer's and Kendal's coefficient of correlation, the relationship between independent and dependent variables was assessed. Using Mann-Whitney test tables, the severity of the correlation coefficients were determined separately. Results and discussion: The test results of the hypotheses showed that factors including knowledge level and gender of interviewees play a significant role in the student’ s participation. On the other hand, due to the limited age range of the target population and their high level of education, these factors didn’ t have much impact on the responsible behavior of the academics. Preferring educational methods such as organizing exhibitions on recyclable products by interviewees, and no impact of face-to-face education, indicated that they are willing to acquire related information through new educational methods. Interviewees asserted that being certain about the expenditure of project revenues on students’ welfare affairs is the main factor in the increase in their participation rate. In other words, because environmental measures are newly developed and social activists have limited experiences, the participation of individuals in waste segregation activities without fulfilling their financial expectations is not feasible. Conclusion: The results of the current study indicated that most students of Nazloo Campus of Urmia University were willing to participate in domestic waste segregation (with a score of 7. 56 out of 9). Unfortunately, due to their inadequate knowledge about the subject (with a score of 4. 54), and lack of associated executive programs in the university (with a score of 1. 96), as well as the lack of training programs provided by the university (with a score of 2. 71), the waste segregation was not implemented properly. Due to the poor evaluation of the university staff’ s performance in the field of providing waste segregation educations, the students had no trust in the university and this fact had a significant effect on their participation in the plan.

Introduction: A green university is a university that considers health, safety and environmental matters in all its activities, including education, research, and all existing services (e. g., administrative, financial, laboratories, workshops). This kind of university can efficiently use resources and consumables to achieve the goals of sustainable development of the community. To prevent environmental crises and move to a healthy environment, the role of higher education institutions is very important. The present study was conducted with the main purpose of analyzing the barriers and strategies for developing the green university from the viewpoint of faculty members of the College of Agriculture and Natural Resources of the University of Tehran. Material and methods: This research is a research based on Structural Equation Modeling which was performed by confirmatory factor analysis. The statistical population of the study consisted of faculty members of the College of Agriculture and Natural Resources of the University of Tehran (N=230). Based on the Cochran formula, 140 people were selected by simple random sampling method, from which 123 questionnaires were selected for the analysis. A researcher-made questionnaire was used to collect data. Validity of the questionnaire was confirmed by the opinion of some faculty members of the University of Tehran. To determine the reliability of the research tools, a pre-test was used. The calculated Cronbach's alpha for the barriers and strategies for the development of the Green University were 0. 87 and 0. 89, respectively. Results and discussion: The results of the confirmatory factor analysis showed that among the five factors of the green building development barriers, the green education component (factor loading = 0. 98), and among the five components of the green campus development strategies, the green research component (factor loading coefficient = 0. 88) had the most important role in explaining the barriers and development strategies of green campus from the viewpoint of the faculty members of the College of Agriculture and Natural Resources of the University of Tehran. Conclusion: Overall, the results of this study showed that there are many effective barriers and strategies for the development of the green university. Based on the findings of the factor analysis, for barriers, green education, green university management system, green human resources system, green research, and environmental management system were the most important factors, respectively. Also, for the strategies, the green research, green university management system, environmental management system, green human resources system, and green education were the most important factors, respectively.

Introduction: Increasing water demand and water pollution due to the development of agricultural, urban and industrial activities have caused environmental problems all over the world. The significant increase in water pollution and the diversity of various urban, agricultural and industrial pollutants made the qualitative management of water resources inevitable. Short-term and long-term accurate forecasts of river quality parameters are essential for designing hydraulic structures, irrigation planning, optimal utilization of reservoirs and environmental planning. Given the stochastic characteristics of the hydrological events, forecasting the future status of surface waters is always associated with uncertainties. The purpose of the present study was to investigate the performance of two types of artificial neural networks, namely MLP and GMDH, combined with discrete wavelet transform (DWT), to forecast two important quality parameters, electrical conductivity (EC) and sodium adsorption ratio (SAR) at Zayandeh-Rood River in 1, 2 and 3 months ahead. Material and methods: In this study, water quality data (EC and SAR) of Zayandeh-Rood River at Zaman Khan Station was used from 1363 to 1384. From 21 years of data, 15 years (approximately 70%) were used for training and 7 years (30%) were used to test the developed models. Two types of mother wavelet dmey and db4 were evaluated. Statistical parameters such as RMSE and R2 were used to evaluate the performance of the models. Results and discussion: The results showed that the use of discrete wavelet transform improves the performance of the models. Various combinations of input data (various delays) and two types of mother wavelets were evaluated. The results showed that wavelet-MLP and wavelet-GMDH hybrid models outperform single MLP and single GMDH models at all forecasting intervals. The results of the single MLP and GMDH models were only effective in forecasting SAR one month ahead but practically could not forecast two and three months later. In the EC parameter, the MLP and GMDH models performed better. Also, the results showed that the use of annual time lags does not increase the accuracy and in some cases even reduces it. The study of the types of mother wavelets also showed that the dmey wavelet is the most suitable wavelet type to forecast EC and SAR qualitative parameters. The comparison between wavelet-MLP and wavelet-GMDH models showed the relative superiority of the former model. By increasing the forecast period from one month to three months ahead, the accuracy of the models decreased. This decrease in precision was higher in forecasting SAR parameter, e. g. in the one month forecast, R2 was 0. 936 and in the 3 months ahead forecasts it was reduced to 0. 516. In the EC parameter, the R2 fell to 0. 641 in 3 months ahead forecasting. Conclusion: The results of this study can be used as a basis for future planning for water quality. It is suggested that the model presented in this study should be considered in other rivers. Also, the combination of other artificial intelligent models such as ANFIS and SVM with wavelet transform can be evaluated.

Introduction: Principal land use management requires accurate and timely information in the form of maps. Considering the widespread and unsustainable changes in land use, including the destruction of natural resources in recent years, it is essential to study the changes in land covers over the time using satellite imagery. Because the conservation of natural resources requires continuous monitoring of an area, land-use change models are now used to identify and predict land-change trends and land degradation. One of the most widely used models in predicting land use change is the automated Markov chain model. The purpose of this study is to monitor land use changes in Abu Ghovair Plain in the past years and predict their status in the next 13 years. Material and methods: In this study, in order to detect the changes in the study, TM, ETM+, and OLI images of Landsat satellite were used in the years 1990, 2003 and 2016, respectively. After applying geometric and atmospheric corrections to images, the land use map was created for each year. Then, to predict the changes in 2029 using the Markov chain in the Idrisi Selva software, the mapping of the years 1990 and 2003 were selected as the input to the model. Then, 13 years of forecasting changes were considered until 2016 to get the matrix of the likelihood of user changes. Then, data from the Markov chain method and the map of 2016 were used as input data for the CA-Markov cell method. Results and discussion: The results of monitoring satellite images from 1969 to 2016 indicated a gradual increase in sandy areas by 62 km2 and its movement towards poor rangelands and shrubs. The agricultural lands were increased so that at the end of the period their size has increased by 67. 68 km2. Residential land has also been expanded over the years, and the size of the shrubland has been reduced. After tracking the changes, the 2016 map was simulated by the model. Evaluating the accordance between the simulated map and the actual map with the Kappa index confirmed the accuracy of the model. Then, the 2029 map was prepared to predict the changes over the coming years. The discovery of changes in 2029 indicated that if the current trend continues, the area of the sand zones will increase to the extent of covering 15% of the area. In this period, the most changes will occur in the middle part of the southeast to the south of the area. The size of the shrubland will decrease by 13 km. The changes in agricultural lands continue to grow and will encompass 10% of the whole region in 2029. Conclusion: Comparison between the simulated map of 2016 generated by the model and actual map with Kappa index showed that Auto-Markov model is a suitable model for predicting land use change and can be used to accurately assess the future status of land use and vegetation.

Introduction: Open spaces are the most important area of human social exchange, which may be affected by a wide range of factors. Encouraging individuals for being outdoor is one of the main factors for economic, social and political development in the cities. Studying and determining the limitations and climate hazards along with noticing their hidden ecological potentials in different seasons of the year should be taken into account for different provincial planning. It can also play a key role in urban and zone planning. For this reason, the objective of this research was the determination of the thermal comfort of people in Qom Province’ s outdoor. Meterial and methods: In this research, predicted mean score (PMV), equivalent physiological temperature (PET) and human thermal comfort in outdoors of Qom Province were analyzed. For this purpose, five parameters including temperature, relative humidity, wind speed, water vapor pressure and cloud coverage in three weather stations of Qom, Kahak, and Salafchegan were extracted in a 12-year period of time (2004-2017). The data were then transferred to RayMan software in different time scales and then PET and PMV were calculated and analyzed. Results and disscussion: Our analyses showed that climate comfort period in this province was limited to two separate periods, which is simultaneous with the transition of the warm period into a cold one or vice versa. This situation contains 7. 92% of the year; the first period is during April and May, while the second period occurs in October. These months were the best times for environmental activities in Qom Province. Because of geographic variety and topographic distribution, the inconsistency of the thermal situation can be clearly observed in this research. Mountainous places were faced with cold tensions in 50. 27% of the year and low altitude places were faced with warm tensions in 51. 63% of the year. Monthly analysis showed that the limiting factors of thermal comfort in the central and eastern part of the province were medium and high thermal tensions in May, June, January, August, and September, while the only limitation of mountainous cities was the cold tensions happening in November, December, January, February, and March. The results showed that the effects of altitude and topographic distribution caused climate variations in this zone, which makes every ecological climate situation possible to happen in Qom province. Conclusion: Results of this research showed that the output of eco-climate factors of PET and PMV has the capability of clarifying comfort and discomfort periods in Qom Province. Besides minor differences, it can present homogeneous phenomenon of comfort climate in this city and provide better information for planning and management purposes. In general, according to different methods, factors, and data analysis, an integration of different factors should be considered to achieve our goals.

Introduction: Environmental assessment of the life cycle of crops in production systems is an accepted method for achieving agricultural sustainability. Moreover, the agricultural sector has a significant contribution to greenhouse gas emissions and global warming. Hence, improving agricultural operations is an appropriate way to mitigate the effects of climate change. Therefore, the aim of this research was the environmental assessment of different scenarios of the production of improved rice cultivars. Material and methods: After preliminary evaluation and consultation with rice specialists, 100 paddy fields were selected for semi-mechanized planting method and 100 paddy fields for traditional planting method in Sari region from 2015 to 2016. After recording the data, each planting method was converted into four planting systems based on agronomic management and input consumption, which formed a total of eight scenarios. Four scenarios of the semi-mechanized method were systems of low-input (SL), conservation (SCI), conventional (SCII) and high-input (SH). Four scenarios of the traditional method were systems of low-input (TL), conservation (TCI), conventional (TCII) and high-input (TH). Results and discussion: The results indicated that the average paddy yield in eight scenarios was 6418 kg. ha-1. The average input energy in eight scenarios was 28138. 93 MJ. ha-1, which contained 45. 44% renewable (biologic) energy and 54. 56% non-renewable (industrial) energy. The highest input energy was observed in scenarios IV and VIII, which was related to the SH in both planting methods. The average output energy in eight scenarios was equal to 197076 MJ. ha-1. The highest output energy was obtained in scenarios III, IV, VII and VIII. The average energy productivity in the eight scenarios was equal to 0. 23 kg. MJ-1 that the least amount was obtained in both planting methods and the other scenarios were on the same level. The average CO2 emissions in all eight scenarios were 1120. 37 kg CO2. eq ha-1, which had the highest share related to seed, fuel, and machinery. In terms of global warming potential per unit area, scenario VIII was ranked first and scenario IV ranked second. The highest global warming potential per grain weight and GWP per input energy were achieved in scenarios I and V. The highest heavy metal emission into water and soil was observed in the SH and SCII, respectively. The highest net primary productivity (NPP) in production scenarios was related to SCII and SH, which was higher in the semi-mechanized method than the traditional method. In both planting methods, the most relative carbon inputs (Ri) were obtained in scenarios of the SH (I and V). With regard to input-output carbon and net carbon in eight scenarios, the average sustainability index was 4. 66. The highest sustainability index was observed in scenario II (5. 05), which was related to the conservation system. The scenarios V, I, III and VI were next ranked in terms of the sustainability index. In fact, the correct management of the paddy field in the SCI has led to a reduction in emissions of environmental pollutants. Conclusion: According to the findings, SL and SCI were closer to sustainable development indicators in both methods. Furthermore, the economic efficiency of rice production was more important to farmers than environmental sustainability and energy efficiency. Hence, using the findings of this research can be very effective in increasing environmental sustainability and reducing the environmental impacts of chemical inputs and achieving agricultural sustainability.

Introduction: Leakage in water distribution networks (WDN) causes loss of water and energy resources. The amount of leakage in WDNs is influenced by pressure. Leakage prediction and optimal decision making on leakage control strategies require a deep understanding of the leakage-pressure relationship. High-density polyethylene pipes (HDPE) have been used extensively in water distribution networks in recent decades, and leakage behavior in this material is still debatable. The purpose of this study was to better understand the leakage behavior of the longitudinal slits of the high-density polyethylene pipes and the effective parameters in their elastic phase. Material and methods: To achieve the objectives of this research, a semi-industrial laboratory model was developed. Based on the preliminary studies and literature review, effective parameters were extracted and then 10 samples were prepared by considering the parameters of diameter and thickness of pipes, dimensions of slits, and temperature. Then, the samples were pressurized by a high-pressure pump and by setting the pressure, the leakage discharge of the longitudinal slits and also the temperature were measured for each pressure during the test. Using the dimensional analysis method, the results were analyzed. Results and discussion: In the longitudinal slit of HDPE pipes, the leakage flow was a function of changes in the area of the leak. Our results showed that there is a relatively linear relation between the change in the effective area of the leak position and the pressure in the elastic state. Also, the rate of changes in the area relative to pressure variations depends on the parameters such as the dimensions of slits, pipe diameter and thickness, and temperature. Among these parameters, the effect of the slits’ length and the temperature had a greater effect on the amount of leakage in longitudinal slits. Using experimental results and dimensional analysis, a relationship was developed to estimate the effective area change of the leak in the longitudinal slits in the HDPE pipes. Using this relationship, leakage can be calculated at different pressures. In the present study, the leakage exponent for longitudinal slits in the HDPE pipe was calculated in the range of 0. 44 to 1. 44 and was consistent with the proposed relationship. In the elastic state, if any of the effective parameters such as slits’ length or pressure increased, the leakage power approached 1. 5. Given the uncertainty about the size of the slits in the water distribution networks, an exact number cannot be proposed for the leakage power, but the average leakage power in our experiment was equal to one. In another experiment, the effect of temperature on leakage was investigated independently at a pressure of 5 bar and showed that an increase in temperature could increase the leakage in HDPE pipes. Also, at 40 ° C, it exited from the elastic state, and the slope of the changes increased significantly. Conclusion: The mean value of the leakage power for the current experiment was equal to one, which corresponds to the previously reported amount that was used to estimate the leakage rate of WDNs. According to this study, a relationship was used to estimate the variation in the area of the leak in terms of the shape and material of the pipe, the shape of the slits and the temperature relative to the pressure. For the first time, the temperature parameter was also investigated in relation to the variation in the area of a slit and discharge leakage. Considering the significant effect of temperature, it is suggested a new relationship to be used in the tropics to estimate the amount of leakage.

Introduction: Taxus baccata is one of the native forest species in Iran. It is one of the most important sources of taxol, an anti-cancer compound. This plant is an endangered species due to its low growth and regeneration and also over-harvesting. Taxol production by tissue culture technique can protect this plant from the danger of extinction. In this study, the improvement of the growth of callus and taxol production in Taxus baccata were assessed using chemical absorbents and antioxidant compounds. Material and methods: Activated charcoal (1 g/l), Polyvinylpyrrolidone (PVP; 250 mg/l) and an antioxidant compound (0. 2 g/l glutamine, 0. 05 g/l ascorbic acid and 0. 05 g/l citric acid) were used for treating in a callus growth medium. Four grams of 60 day-old calli were transferred to a callus growth medium containing each of the treatments, where the untreated culture medium was considered as the control group. After 21 days, the amount of callus browning, wet weight, dry weight and viability as growth and morphological factors and also hydrogen peroxide (H2O2), malondialdehyde, total phenol, polyphenol oxidase activity and taxol amount as phytochemical factors were studied and evaluated. Results and discussion: The results of morphological and phytochemical changes of calli under treatments showed that the antioxidant compound reduced the H2O2 and lipid peroxidation amount and with the reduction of oxidative stress, browning of tissues decreased. Also, under this treatment, with decreasing total phenol and activity of phenoloxidase, the amount of phenol oxidation decreased significantly. So, cell viability and wet and dry weight were increased and the amount of tissue browning was decreased. By absorbing the phenolic compound, activated charcoal and PVP decreased the polyphenol oxidase activity. The decrease in the polyphenol oxidase activity increased cell viability and prevented tissue browning. Under these treatments, no significant changes in H2O2 and MDA content, and wet and dry weight was observed. No changes were observed in the callus growth, which may be due to the absorption of hormones and vitamins along with the absorption of toxic compounds from the medium. Conclusion: All treatments were effective in decreasing the amount of tissue browning and increasing the viability of calli, but antioxidant compound treatment was the most effective in improving growth and increasing wet and dry weight with increasing taxol. Therefore, it is suggested as the best treatment for optimizing the callus culture of yew.

Introduction: The presence of iron in groundwater, even at low concentrations, results in many problems regarding the drinking water. Iron increases the growth of chlorine-resistant microorganisms in drinking water distribution system, leading to an increase in disinfection cost, in addition to problems regarding changes in odor and taste of water. In order to remove iron from water, diverse techniques are being used including oxidation and filtration, absorption or catalytic bed filtration, ion exchange, softening, biofiltration and adsorption. One of the cheapest methods to remove iron from drinking water is adsorption by cheap minerals such as glauconite. In this study, drinking water iron removal by two mineral absorbent glauconites from Sarakhs and Maraveh Tapeh has been investigated. Material and methods: The natural glauconites were collected from glauconitic sandstones in Sarakhs (Neyzar formation) and Maraveh Tapeh (Aitamir formation) and were processed in the laboratory and graded in particle diameter 0. 5-1. 0 mm. The specific surface area and volume of the cavities of the two specimens were determined by BET analysis by nitrogen absorption method. In order to study the kinetic and equilibrium behavior of the adsorption process, iron adsorption kinetic and adsorption isotherm curves on glauconite absorbents have been determined through experimental tests. These tests were done at three pH levels (5, 7, and 9). The aqueous solutions containing 5 mg/l of iron in a volumetric flask were exposed to different amounts of the absorbent at a constant temperature (20 ° C). Results and discussion: BET analysis as a nitrogen absorption method revealed the specific surfaces of the two glauconite samples from Sarakhs and Maraveh Tapeh as 0. 999 and 2. 833 m2/g, respectively. The pore volume of Sarakhs and Maraveh Tapeh glauconites were measured as 0. 006 and 0. 0123 cm3/g, respectively and the average pore diameter were determined 24. 07 and 17. 31 nm, respectively. The results indicated that as the pH increased, the iron adsorption capacity and absorption rate by the glauconite from Sarakhs and Maraveh Tapeh increased significantly. Comparing the iron adsorption of glauconites revealed that the extracted glauconite from Maraveh Tapeh had more iron adsorption capacity than that of Sarakhs, corresponding to the higher specific surface area of this absorbent. At pH 5, 7, and 9, the ultimate absorption capacity of glauconite from Maraveh Tapeh was 17. 3, 11. 7 and 13. 9 % higher than that of Sarakhs. The kinetic model regression indicated that Hu et al. and Ritchie's models have absolutely similar behavior in describing the iron adsorption kinetics curves on glauconite absorbents. Eventually, it can be stated that the process of iron adsorption by glauconite follows the second order kinetics. The best isotherm model to describe the iron adsorption equilibrium data on glauconite are the models developed by Temkin and Davoudinejad. Accordance with Davoudinejad's model demonstrates the presence of monolayer adsorption along with heterogeneous adsorbent surface and steric hindrances for absorption. Complying with Temkin’ s model indicates that absorption enthalpy is a linear function of absorbent surface loading. Conclusion: Glauconite mineral absorbents extracted from Sarakhs and Maraveh Tapeh performed better than natural Zeolite and Kaolin and had similar performance to Manganese zeolite, Pyrolusite, and Pumice for iron absorption from the water. Regarding their abundance in Iran, they can be used as an affordable method to solve the problem of the presence of iron in drinking water in Iran.