Antibacterial effect of TiO2 modified with poly-amidoamine dendrimer – G3 on S. aureus and E. coli in aqueous solutions

This study investigated the bacterial removal using TiO2 nanoparticles (NPs) modified with poly-amidoamine dendrimer macromolecule (PAMAM, G3). The PAMAM G3/TiO2 (nanohybrid) was used to specify antibacterial properties via broth microdilution (MBC-Minimum Bactericidal Concentration and MIC-Minimum Inhibitory Concentration- determination), paper disc diffusion, and surface plate count methods. The nanohybrid was characterized via the different techniques. The effects of different factors including initial bacteria count, run time, solution pH, and the nanohybrid concentration were studied. The nanohybrid cytotoxicity was studied on AGS and MKN45 cells line by MTT assay. It was revealed that the nanohybrid was effective in intercepting both bacterial strains growth. The MIC value for S. aureus and E. coli were determined to be 4 and 2 μg/mL, respectively. The MBC value for both strains were calculated to be 32 μg/mL. The results showed removal efficiency of 100% for S. aureus and E. coli bacteria in optimum situation. The decrease in cell viability in the dosage of 32 μg/mL after 72 h treatment for AGS and MKN45 cells line were shown to be 6.2 and 4.6%, respectively. The nanohybrid was able to decrease the S. aureus and E. coli count in solution, which meets the drinking water criterions aligned with WHO guidelines.

Plume-induced subduction and plate fracturation, deep mantle overturn, and the onset of plate tectonics.

<p>Mantle dynamics can now be recovered in the laboratory, when aqueous colloidal dispersions are dryed from above, and either insulated or heated from below. As their rheology varies from viscous to visco-elasto-plastic to brittle when drying proceeds, a skin (i.e. an experimental lithosphere) develops at the surface. Submitted to buckling, small-scale convection, or an impinging hot plume, this skin can break and one-sided subduction is then observed to proceed. In the case of plume-induced subduction (PIS), the impact of the plume under the skin induces tensile fractures, plume material upwelling through them and spreading at the surface, analogous to volcanic flooding, leading to skin bending and eventually one-sided subduction along arcuate segments which retreat away from the plume. A system of accreting ridges can develop inside the back-arc basin. If PIS develops isolated in an overall stagnant lithosphere, subduction eventually either stops as the result of subducted plate necking, or when plume spreading stops. On the other hand, if the lithosphere contains other heterogeneities (damage) such as faults, accretion ridges or another PIS event, the weight of the subducting plate can induce faraway plate breaking and horizontal mobilization of the surface plate.</p><p>As the lithosphere has to accumulate damage to fracture, it takes time from the first subduction event to the organization of a network of subducting and accreting plates. But the presence of several hot plumes simultaneously accelerates the establishment of an organized pattern of plates, subduction and accretion. And when we run experiments where the mantle contains initially a denser layer at the bottom, the global overturn of this dense layer results in the simultaneous generation of plumes over the whole mantle surface, which produces a burst of PIS events and the quick establishment of a plate tectonic-like regime. <br>Such a global overturn has been proposed to explain the big peak in continental crust growth 2.7 Ga on Earth. Our experiments suggest that it could also have triggered the formation of the plates boundaries and flow organization necessary to plate tectonics.</p>

A sensor based assessment of ignition delay for pure diesel and biodiesel blends in an isochoric combustion box

The key to efficient operation of a diesel engine is the smooth combustion of the fuel and controlled detonation. In diesel engine detonation depends on ignition delay (ID) period. An isochoric cylindrical combustion box (CCB) is fabricated for the assessment of ID tendency for simple diesel and vegetable oils-diesel fuel blend (VODFB). The combustion box consist of air heating coils, hot surface plate, fuel injector, pressure gauge, temperature indictor, temperature controller and photo sensor. A two stage compressor with intercooler is used for charging the air in the combustion box. The ignition lag was measured for injection pressures (IP) (100-bar, 200-bar and 300-bar), hot surface temperatures (400°C and 450°C), cylinder pressures (10, 15, 20 and 25-bar) for simple diesel and VODFB by using photo sensor and scope-meter. The results show that ID was decreased with increase in IP, at a specific cylinder pressure and HST for both simple diesel and VODFB. At high IP (300-bar), ID is lower for the blended fuel because at high IP, the fuel covers more physical land and more fuel is vaporized within a given time period and hence ID time decrease.

Lab Manual for Metrology and Machine tools

In this lab course, students can understand different machining processes through laboratory experiments. The students must have a fairly good understanding of the theory underlying the experiments before doing the experiments. The students can perform various tests such as 1. Use of gear teeth vernier callipers for checking the chordal addendum, 2. Machine tool alignment of test on the lathe, 3. Toolmakers microscope and its application, 4. Angle and taper measurement by bevel protractor and sine bar, 5. Use of spirit level and optical flats in ?finding the the flatness of the surface plate, 6. Thread measurement by 2-wire and 3-wire methods, 7. Introduction to general-purpose machine tools- lathe, drilling,milling and shaper machines, 8. Step Turning and aper turning on lathe machine, 9. Thread cutting and knurling on lathe machine, 10. Drilling and tapping operations

Numerical simulation of the effect of fault inclination on the sudden water of the fault bottom plate

The main reason for the frequent occurrence of water accidents on the bottom plate of the working surface near the mine fault in China is that the excavation activities cause the fault to activate and direct the pressure water of the aquifer. The distribution of ground stress fields and plastic regions under the influence of extraction disturbance spree is analyzed by using the flaC3D simulation software FLAC3D simulation software. The results show that the greater the inclination of the fault, the greater the shear stress and the normal stress at the fault level, and the deeper the activation range of the mining fault is larger than that of the shallow one ,and the small inclination positive fault is more likely to produce the fissure between the working surface base plate and the aquifer, and the small inclination positive fault should be left with a wider water-bearing coal column in the actual safety design. Using this software, the evolution of the stress field and plastic zone in the adjacent mining area is a preview, which is of great application value to prevent the surface plate burst water and determine the retention width of the fault waterproof coal column.