Self-similar structure of a hot magnetized flow with thermal conduction

We have explored the structure of hot magnetized accretion flow with thermal conduction. The importance of thermal conduction in hot accretion flows has been confirmed by observations of the hot gas surrounding Sgr $A^*$ and a few other nearby galactic nuclei. For a steady state structure of such accretion flows a set of self similar solutions are presented. In this paper, we have actually tried to re-check the solution presented by Abbassi et al. (2008) using a physical constrain. In this study we find that Eq 29 places a new constrain that limits answers presented by Abbassi et al. 2008. In that paper the parameter space in which it is established in the new constrain was plotted. However, the new requirement makes up only a small parameter space with physically acceptable solutions. And now in this manuscript we have followed the idea with more effort, and tried to find out how thermal conduction influences the structur of the disks in a physical parameter space. We have found out that the existence of thermal conduction will lead to reduction of accretion and radial and azimuthal velocities as well as the vertical thickness of the disk, which is slightly reduced. Moreover, the surface density of the disk will increase when the thermal conduction becomes important in the hot magnetized flow.Comment: Accepted for publication, AP

Effect of Methyl jasmonate treatment on antioxidant capacity, internal quality and postharvest life of raspberry fruit

Native population of raspberry fruits (Rubus spp) were treated with Methyl Jasmonate (MJ) fumigation and were assayed for the antioxidant capacity, total anthocyanins and postharvest quality after 7 days storage at 4?C. The result of experiment revealed that berries treated with methyl jasmonate (MJ) showed higher antioxidant capacity and total anthocyanins compared to the controled ones (non-treated). Decay incidence was reduced in fumigated fruits during storage at 4?C, which resulted to long postharvest life (as indicated by fugal decay) compared to the controled ones. Total soluble solid, titratable acidity and pH were influenced by storage periods. Therefore, MJ treatments could not suppress the declining, which happened during storage time. In conclusion, although raspberry fruits treated with MJ maintained higher levels of antioxidant capacity, total anthocyanins compared to untreated fruits during storage, but because of high perishable, MJ treated fruits could not maintain significant changes in internal quality

Effect of chitosan coatings on some quality indices of apricot (Prunus armeniaca L.) during cold storage

In this study, the effectiveness of chitosan coating treatment to control weight loss and maintaining fruit quality of apricot was investigated. Fruits were coated with 0.25%, 0.5% and 0.75% chitosan as well as distilled water (control). Following treatments, fruits were stored at 0?C and 80 ? 2% relative humidity for 25 days. The weight loss, total soluble solids (TSS), titratable acidity (TA), TSS/TA, pH, vitamin C, total phenolics and antioxidant activity (DPPHsc%) were followed at an interval of 5 days up to 25 days. Weight loss from all treated and untreated fruits increased over storage time. The weight loss of chitosan coated fruits was increased in comparison to untreated samples. There was no significant difference for total soluble solids (TSS), titratable acidity (TA), TSS/TA, pH, vitamin C in coated and uncoated fruits storage. Chitosan coatings significantly increased the content of total phenolics and antioxidant activity, as 0.5% chitosan showed maximum total phenolics (82.65 mg GAE/100g) and antioxidant activity (23.77 DPPHsc%). The chitosan coatings proved to induce the antioxidant capacity and also to sustain the total phenolic content

Evaluation of six cold-season turfgrasses responses to lead phytotoxicity for screening tolerant species

Lead (Pb) is one of the most hazardous heavy metal that caused serious problems for ecosystem at recent years. In this study, the effect of Pb on seed germination, incipient growth and antioxidant enzymes of six common used turfgrasses was investigated. The results showed that after implementation of different concentrations (0, 1000, 2000 and 3000 µM) of Pb, Agropyron elongatum exhibited the highest germination percentage (90%) under 3000 µM Pb, followed by Lollium perenne L. (85.56%). The lowest germination parameters including germination vigor, rate, index and germination percentage was found in Festuca ovina, which means it is the most sensitive species to Pb than the other studied turfgrasses. In contrast, F. rubra, F. ovina, A. elongatum and L. perenne had the most significant aerial growth and the lowest chlorophyll degradation even at high lead concentration. An increase in L. perenne and A. elongatum antioxidant enzymes activities as well as a decrease in F. ovina observed after exposure to 3000 µM Pb which correlated to their tolerance and sensitivity to Pb respectively. However, such increase in antioxidant activity was also found in F. Rubra and Poa pratensis but could not inhibit chlorophyll degradation and seedling growth retardation. It might support that there is suggesting the probable existence of a lead-injury mechanism rather than the oxidative stress. Overall, A. elongatum is introduced as the most tolerant turfgrass among studied ones, which could be cultivated in Pb-polluted sites

The Comparison of Some Chemical Treatments and Carvacrol on Improving Vase Life of Cut Alstroemeria Flower CV. Bridal

Premature leaf yellowing of Alstroemeria cut flowers prior to petal fall is the most important limiting factor of the flower postharvest life. In this study, cut flower Alstroemeria cv. Bridal were treated for 24 hours with different solutions including gibberllic acid, benzyl adenine, natural essential oil carvacrol with two concentrations of 50 and 100 mg L-1, 5-sulfo salicylic acid in two concentrations of 1 and 1.5 mM, sucrose in  two concentrations of 5 and 10%. Ethanol and distilled water were used as controls. After treatment, flowers were placed in distilled water. The traits including vase life of flower and leaf, relative fresh weight, water uptake, chlorophyll and carotenoids contents were measured. The results showed that both concentrations of gibberellic acid (50 and 100 mgL-1) had the highest effect in delaying of flower aging for 3.33 and 3 days, respectively, compared to the control. Relative fresh weight and water uptake also were higher in mentioned treatments, than the other treatments. The gibberellic acid (50 and 100 mg L-1), benzyladenine (100 mg L-1) and 5-Sulfo salicylic acid (1.5 mM) treatments led to the postponement of leaf yellowing relative to the remaining treatments. Also, in the mentioned treatments chlorophyll content was found to be greater than the other treatments, but carotenoids level was lower, compared to control treatments. Overall, the increase in quality and shelf life of Alstroemeria cut flowers cv 'Bridal' due to both gibberellic acid treatments (50 and 100 mg L-1) was found to be greater than the increase due to the other examined solutions

Effect of Fruit Harvest Time on Oil Yield and Quality of Some Olive Olea europaea L.) Cultivars in Roudbar Region

Fruit ripening stage at harvesting time is potentially a major contributor to olive oil yield and quality. Therefore, one of the main causes for low olive oil quality, at least in northern Iran, is harvesting fruits at improper time. In this study, effect of fruit harvest time on oil yield and quality of four olive cultivars, Zard, Rowghany, Arbequina and Coratina was investigated at Roudbar region, Guilan Province, northern Iran. The fruits of all studied cultivars were harvested at four different times and the characteristics such as fruit maturity index, oil percent, free fatty acid, peroxide value, K232, K270, and sensory quality of oil were evaluated. The results showed that in contrast to free fatty acid and peroxide values which increased with progressing fruit ripening, oil sensory quality for all studied cultivars were decreased. In addition, while a delay in fruit harvesting time resulted in an increased K270 value, no such changes were observed for K322. Overall, delay in fruit harvesting was concomitant to increase in oil percent and decrease in oil quality.  According to the results of this study, the optimum harvest time for olive cultivars Zard, Rowghany, Arbequina and Coratina at Rodbar under the conditions of this experiment seemed to be at fruit maturity indices of 3.47-4.21, 4.42-5.2, 3.9-5 and 3.9-4.25, respectively

Correlation between Content and Ratio of Fruits’ Mineral Elements at Harvest and Postharvest Life of Kiwifruit Cv. Hayward in Orchards of Eastern Part of Guilan Province

The main factor affecting fruit quality and post-harvest loss in kiwifruits is improper tree nutrition. In this study, fruits were harvested from 24 different orchards in the east of Guilan province when the total soluble solid content of the fruit was 6.2°. percent the fruts was. Fruits’ mineral content such as nitrogen, phosphorus, potassium, calcium and magnesium, the mineral elements ratios and also fruits firmness were measured after harvest. Thereafter, fruits were transferred to cold storage at 0 ºC temperature and 90% relative humidity and after 15 weeks, fruit tissue firmness, water loss, ethylene content and respiration severity were measured. There was a significant positive correlation between fruits tissue firmness with fruit calcium content, but a significant negative correlation with potassium and nitrogen content, N:Ca, N+K:Ca. K:Ca and K+Mg:Ca ratios. At the end of storage, there was a significant positive correlation between fruit tissue firmness with calcium content at harvest time and a significant negative correlation with nitrogen, phosphor us and potassium content and N:Ca, N+K:Ca, K:Ca and K+Mg:Ca ratios. Furthermore, fruits’ weight loss showed a significant positive correlation with potassium content. There was a significant negative correlation between ethylene level and fruit tissue firmness at the end of storage and a positive correlation with N:Ca and N+K:Ca ratios. Cluster analysis divided kiwifruit orchards into two main groups. In conclusion, the results showed that the kiwifruit mineral elements’ content and ratio at harvest time can be used as an effective factor for evaluating post-harvest life of kiwifruits