Increase In Outflow Rate Research Articles

Ionised outflows inz~ 2.4 quasar host galaxies

AGN-driven outflows are invoked by galaxy evolutionary models to quench star formation and to explain the origin of the relations observed locally between super massive black holes and their host galaxies. This work aims to detect the presence of extended ionised outflows in luminous quasars where we expect the maximum activity both in star formation and in black hole accretion. Currently, there are only a few studies based on spatially resolved observations of outflows at high redshift, $z>2$. We analyse a sample of six luminous (${\rm L>10^{47} \ erg/s}$) quasars at $z\sim2.4$, observed in H-band using the near-IR integral field spectrometer SINFONI at VLT. We perform a kinematic analysis of the [OIII] emission line at $\lambda = 5007\AA$. [OIII] has a complex gas kinematic, with blue-shifted velocities of a few hundreds of km/s and line widths up to 1500 km/s. Using the spectroastrometric method we infer size of the ionised outflows of up to $\sim$2 kpc. The properties of the ionised outflows, mass outflow rate, momentum rate and kinetic power, are correlated with the AGN luminosity. The increase in outflow rate with increasing AGN luminosity is consistent with the idea that a luminous AGN pushes away the surrounding gas through fast outflows driven by radiation pressure, which depends on the emitted luminosity. We derive mass outflow rates of about 6-700 M$_{\odot}$/yr for our sample, which are lower than those observed in molecular outflows. Indeed physical properties of ionised outflows show dependences on AGN luminosity which are similar to those of molecular outflows but indicating that the mass of ionised gas is smaller than that of the molecular one. Alternatively, this discrepancy between ionised and molecular outflows could be explained with different acceleration mechanisms.

Effect of processing methods on the degradability of rattle box (Crotalaria retusa) plant in Yankasa rams

Crotalaria as a feed has great ability to serve as a source of energy and protein in dry season feeding due to the fact that it has good crude protein content comparable to other well-known forage legumes. The study was designed to evaluate the nutritive compositions of Crotalaria retusa leaves subjected to various processing. The processing methods that the crotalaria leaves were subjected to include: sun drying, oven drying, shade drying and fresh, and thereafter, the chemical analysis of the variously processed leaves was determined. Similarly, the rumen degradation was determined. The results showed a significant difference in the fresh leaves for all the parameters determined. Dry matter degradability showed a general increase with increase in the incubation time, and there was also a general decrease in passage rate with increase in outflow rate (‘k’ value). Sun drying reduces the protein content for ruminant use as such Crotalaria can serve as a source of protein for ruminants especially in dry season when there is scarcity of protein sources for ruminants.

The importance of shunt valve position in flow characteristics of the Medtronic PS Medical Delta valve

This study was conducted to document the extent to which flow depends on valve position in relation to head-pressure reference. Medtronic PS Medical Delta valves (contour model, performance levels 0.5, 1.0, 1.5, and 2.0) were studied in a bench test designed to evaluate flow rates with respect to valve position in relation to the head-pressure reference postion. The valves were connected to an "infinite" reservoir by the standard inlet catheter. An initial head (proximal) pressure was selected for each valve based on package insert data. The position of the inlet catheter tip was fixed at this starting head pressure, thus making the inlet catheter tip position the reference for relative head pressures on the valve assembly. When the valve body is positioned above this level, the effective head pressure is lowered, and when the valve body is positioned below this level, the effective head pressure is raised. Flow was established with the siphon control portion of the valve body located on the same horizontal level as the inlet catheter tip (the reference head pressure or "0" position). A standard silastic catheter was attached to the outlet of the valve, and its length was fixed at 50 cm for all valves (-50 cm H(2)0). The distal end of the outlet catheter was connected to a fraction collector, and 1-minute samples (five replicates) were collected for gravimetric determination of flow rate. The valve assembly was then moved in 1-cm increments through the range of 4 cm above to 8 cm below the head-pressure reference position. Samples were collected from each position (4 cm to -8 cm) relative to the inlet catheter tip. Flow rate, in milliliters/hour, was plotted against both relative position (4 cm to -8 cm) and absolute head pressure (in centimeters of water). Each of the valves tested was shown to have a linear relationship between flow and position relative to the inlet catheter tip (or absolute head pressure). The average increase in flow per centimeter of displacement of valve from catheter tip was 16.5 ml/hr/cm (range 14.4-17.6 ml/hr/cm). Once the inlet catheter tip is fixed in position, it serves as a pressure reference. Movement of the valve above this level results in a net decrease in effective head pressure, and movement below this position results in a net increase in effective head pressure. Thus, the positioning of shunt valves in locations different from this pressure reference position should be performed only with the knowledge that significant increases in outflow rate may occur when the valve body is positioned lower than the inlet catheter tip. This increase in outflow rate is not the result of siphoning or a defect in the antisiphon device but instead the result of a net increase in effective head pressure.