Showing 5 results for Sadeghipour
Volume 8, Issue 3 (Summer 2020)
Abstract
Aims: The present study aims to monitor and assess CO2 emission from the soil of different land uses and land covers including rangelands, farmlands, mines, gravel lands, and bare lands (lands characterized with no vegetation) in monthly and annual temporal scales.
Materials & Methods: Monthly carbon emission was monitored according to the alkali-trap method in a closed static chamber from mid-March 2015 to mid-February 2016. Data on emissions and land use were analyzed in a factorial experiment in a completely randomized design with four replications. To determine the relationship between temperature and humidity factors with changes in carbon emission in each land use, Pearson correlation coefficient was used.
Findings: The highest (about 3.44g C/m2/d) and the lowest (0.13g C/m2/d) emission rate was found in mines (in July 2016) and in gravel lands (in January 2016), respectively. The results also showed a seasonal pattern (high in summer and low in winter) of CO2 emission. It was found that while carbon emission positively correlated with soil moisture, it showed a negative correlation with soil temperature in mines.
Conclusion: The results depicted that land management should include proper land use selection and improper land use changes should be avoided.
Volume 9, Issue 1 (Winter 2021)
Abstract
Aims: Studying the effects of nanoparticles on living organisms seems to be necessary, especially in plants as the first trophic level. Thus the phytotoxicity of different concentrations of nano-TiO2 on five desert plant species was investigated in the present study.
Materials & Methods: The phytotoxicity of different concentrations (0, 10, 100, 500, 1500mgl-1) of nano-TiO2 on five desert plant species of Halothamnus glaucus Botsch, Haloxylon aphyllum L., Nitraria schoberi L., Zygophyllum eurypterum Boiss. & Buhse, Halocnemum strobilaceum were investigated using seed germination percentage, radicle, and plumule elongation measurement. Experiments were conducted based on a completely randomized design with four replications.
Findings: Outcomes of the study demonstrated that the application of nano-TiO2 had no adverse effect on germination at low concentrations (up to 500mgl-1), it also increased the germination of H. aphyllum (72 to 88%). The concentration of 1500mgl-1 had a negative effect on germination and radicle growth of three species of N. schoberi (decrease in germination from 32 to 20% and radicle length from 13.85 to 10.68cm), H. aphyllum (decrease in germination from 72 to 44% and radicle length from 6.105 to 4.03cm).
Conclusion: Generally, in most plants, low concentrations of nano-Tio2 did not significantly affect germination and seedling growth, but in high concentrations (1500mgl-1) due to toxicity effect, germination and seedling growth were reduced. Therefore, in using nanoparticles, attention to dosage, which is useful and not causes toxicity, is significant.
Volume 13, Issue 2 (Summer 2023)
Abstract
Aims: With the increase of human activities in the city, vegetation and natural cover has always decreased and as a result gives its place to the phenomenon of thermal radiation. The phenomenon of urban heat island (UHI) is usually evaluated by the land surface temperature (LST). The negative effects of LST on urban climate can be manifested by sudden increase in rainfall and unexpected weather effects. Therefore, the stability of population centers will face a serious risk and threat. In addition to climatic factors, population changes and changes due to settlement can also affect the temperature of the city.
Methods: In order to achieve the goal of the research, the temperature changes of the city surface between 2012 and 2015 were estimated through Landsat 8 satellite images, and finally, according to the changes and population movements in the 22 districts of Tehran, a spatial-spatial comparative comparison was made between the two. The variable has been measured and evaluated.
Findings: The results indicate that there is a direct relationship between demographic changes and thermal changes in 12 municipal areas. In 8 regions, this relationship is inverse and in 2 regions out of 22 regions, no significant relationship was observed between demographic and thermal changes.
Conclusion: In general, it can be seen that there is a significant relationship between population changes and temperature changes in Tehran metropolis. The increase in the temperature of the earth's surface, which means more human exposure to heat, will change the quality of life.
Volume 16, Issue 87 (5-2019)
Abstract
Date fruit (Phoenix dactylifera L.) is a rich source of sugar, fiber, some vitamins, minerals and antioxidant phenolic compounds. The physico-chemical, biochemical and microbial changes occurring in this fruit reduce its quality properties during storage time. In the present study, the effects of polyethylene film containing 1 and 2% zinc oxide nanoparticles as nanocomposite packaging and film without nanoparticles as a control were evaluated in order to maintain some quality characteristics of Mazafati date fruit in two storage temperatures of 4 and 25 °C for 120 days. The results of analysis of variance showed that the effects of nanocomposite film, temperature and storage time on the studied parameters of Mazafati date were significant (p <0.05). The least changes in quality parameters of weight loss, pH, titratable acidity, total soluble solids, total phenolic content and total and reducing sugar contents were observed in date samples packed in 2% nanocomposite film stored at 4 °C. The change in control sample stored at 25 °C was significantly higher than other samples. In addition, the use of nanocomposite packaging reduced the microbial growth rate (total aerobic mesophilic bacteria, and mold and yeast) compared to the control sample. With increasing storage temperature from 4 to 25 °C, an increasing trend was observed in microbial growth and changes in the quality parameters of all samples, which indicated a decrease in the quality characteristics of the date fruit. Considering the studied parameters, nanocomposite packaging containing 2% zinc oxide had better performance than nanocomposite packaging containing 1% zinc oxide. In general, the use of nanocomposite film containing 2% zinc oxide nanoparticles is suggested to maintain the quality characteristics of Mazatifi dates at a temperature of 4 °C.
Volume 20, Issue 4 (12-2018)
Abstract
Objective: Cryptorchidism is the most common deficiency of the male reproductive system and most prevalent endocrine disease of boys at birth. Insufficient prenatal anti-Müllerian hormone (AMH) secretion from Sertoli cells of the testis is one of its causes. The role of this hormone and inhibin B in fertility has recently been proven. AMH is a known indicator of Sertoli cell function. The aim of this study was to assess the relationship between anti-Müllerian hormone, inhibin B, testosterone, and semen parameters in post-pubertal cryptorchidism patients.
Methods: We gathered the data of this cross-sectional study from blood and semen samples of 20 patients who had a history of unilateral cryptorchidism. Patients, 20-40 years of age, referred to the Urology Ward of Shariati Hospital, Tehran, Iran. Serum levels of AMH, inhibin B and testosterone were analyzed by enzyme-linked immunosorbent assay. Semen analysis was performed by means of a computer aided semen analysis system 6.5.0. Pearson’s correlation test was used to evaluate the relationships between variables.
Result: Significant positive relationships were existed between total sperm motility and sperm concentration (r=0.086; p<0.01), total motility and fast progressive motility (r=0.97; p<0.01), sperm concentration and fast progressive motility (r=0.9; p<0.01), white blood cell count and sperm concentration (r=0.63; p<0.05), white blood cell count and sperm motility (r=0.66; p<0.05), white blood cell count and sperm fast progressive motility (r=0.77; p<0.01), and testosterone levels and serum AMH (r=0.6; p<0.01).
Conclusion: Cryptorchidism patients in this study had lower serum concentrations of AMH, inhibin B and testosterone than the normal limits. Despite the positive correlation between serum testosterone and AMH, none of the investigated hormones showed any significant relationship with semen parameters.
