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Showing 3 results for Moshref
Volume 6, Issue 3 (Summer 2020)
Abstract
Background: Due to the side effects of chemical and synthetic antibiotics and the increase in bacterial resistance, extensive research has been conducted to obtain natural compounds without side effects from natural sources such as insects, especially Diptera order, because these insects require to live and survive on rotting food and be in direct contact with pathogenic and dangerous microorganisms because of their special diet.
Materials & Methods: In this study, hemolymphs were extracted from Musca domestica, Drosophila melanogaster, and Sarcophaga nodosa, and then the anti-bactericidal activity of these extracts against important pathogenic bacteria was investigated separately by the minimum inhibitory concentration (MIC) method using resazurin indicator.
Findings: S. nodosa and M. domestica larvae were not able to prevent the growth of any of the bacteria. D. melanogaster larvae extract completely inhibited the growth of Escherichia coli and Pseudomonas aeruginosa bacteria at all densities, while Staphylococcus aureus was completely resistant to all concentrations. The minimum inhibitory concentration of D. melanogaster larvae extract against two bacteria of Listeria monocytogenes and Salmonella typhimurium was determined as 125 and 500 μL/mL, respectively.
D. melanogaster pupae extract was unable to inhibit the growth of E. coli and S. typhimurium but prevented the growth of P. aeruginosa at all concentrations. Also, the minimum inhibitory concentration of this extract against both S. aureus and L. monocytogenes was determined as 1000 μL/mL.
Conclusion: These outcomes show that D. melanogaster holds a high potential of antibacterial effects, and the purification and evaluation of this extract active substances are recommended for future utilization as antibacterial agents and food preservatives to fight pathogenic and toxigenic microorganisms.
Volume 12, Issue 48 (9-2015)
Abstract
Active packaging is one of the innovative concepts in food packaging that has been used for controlling environmental parameters such as moisture content in the package. In this study the quality and quantity characteristics of button mushroom were investigated by color, maturity index, opening caps and weight loss after the storage at refrigerator temperature (5 ±2 ° C). The treatments included packaging film at two levels: (clear PVC box and stretch PVC), moisture absorber at four levels: and storage time at five levels: (0, 4, 8, 12 and 16 days). Four moisture absorber treatments were included: the first treatment containing silica gel 1.25 g, the secondary treatment silica gel 2.5 g, the third treatment only spongy foam, the forth treatment containing silica gel 1.25 g and spongy foam. The analyses showed that the stretch PVC in comparison to clear PVC films had the lowest open cap mushroom and weight loss. Silica gel (1.25g) treatment and only foam treatment with stretch PVC film had the lowest open cap. The sensorial evaluation showed there was no significant difference between treatments in terms of maturity index. In terms of cap color, judges preferred button mushrooms treatments by silica gel (1.25 g) with clear PVC box and Silica gel (1.25g) with stretch PVC treatments and there were significant differences between them and other treatments.
Volume 20, Issue 1 (4-2020)
Abstract
Undoubtedly, fluid flow modeling plays an important role in underground structures studies. In many cases, the main system for fluid flow in rock mass is the fractures network. Because of that the measurement of the geometric properties of the discontinuities is a time-consuming process and for some properties like persistence is impossible, the use of stochastic modeling for rock mass is suggested. Uncertainty about the geometric properties of discontinuities has led to use of statistical analysis for more accurately define geometric features. Because of intrinsic statistical nature of the geometric features of discontinuities, a more precise model can be obtained from the development of stochastic three-dimensional geometric models of discontinuities. The most important step in rock mass modeling is the exact definition of the discontinuity network. This makes it possible to provide a better starting point for numerical modeling in mechanical and hydraulic analysis. The Gardaneh-Rokh tunnel with a length of 1300 meters and a maximum volume of 200 meters is located in Chaharmahal Bakhtiary province. The purpose of this study was to investigate the water leakage from joints and fractures in the tunnel and the effect of surface water in the amount of water leakage into the tunnel using analytical and numerical methods. This modeling has been done to increase the understanding of the hydraulic behavior of the massive discontinuity system. In this study, the fractures connected to each other as the main paths of water flow into the tunnel and the control of the hydraulic behavior of the mass are assumed, and the roughness of the joints is neglected To this paper, joint sets in Gagrdaneh Rokh tunnel was modeled using the 3D-DFN code written in the Mathemtica software, after validation of the surveyed and modeled values, it was observed that the percentage of conformance is above 85%. This has led to the use of model outputs with confidence in the hydraulic modeling of the tunnel. This paper is designed with the aim of two-dimensional hydraulic modeling in the UDEC software environment. The modeling fluid is considered as monophasic, and discontinuities are modeled as two-dimensional. Hydraulic modeling is done by calling the joints from the 3D-DFN program output. Comparison of the obtained results shows good matching between the flow rate in the model with the actual flow rate. The resulting total flow rate is estimated to be 362 liters per minute, which is actually set at 375 liters per minute, which is a good match. Also, the sensitivity analysis of fluid flow has been investigated with respect to the maximum and minimum values of apertures, continuity (trace length) and Fisher numbers. With an opening of 5 mm, the water rate to the tunnel will reach 530 liters per minute. This rate is reduced to 172 liters per minute at opening of 1.2mm. The flow rate arrives in continuity of 27 meters to 523 liters per minute, in a trace length of 22 meters to 488 liters per minute and in trace length of 10 meters to 354 liters per minute. The flow rate in Fisher's number is reduced to 410 liters per minute and in Fisher's number 25 to 290 liters per minute.
