Effect of the amount of additional filtration on the contrast-to-noise ratio. The percent CNR improvement of rhenium over iodine is increased as the amount of additional filtration is increased. The concentration of rhenium and iodine in the XCA was 200 mM. The XCA were imaged by µCT. All the scans were conducted at 120 kVp.
Figure 6. Effect of the amount of additional filtration on the contrast-to-noise ratio. The percent CNR improvement of rhenium over iodine is increased as the amount of additional filtration is increased. The concentration of rhenium and iodine in the XCA was 200 mM. The XCA were imaged by µ CT. All the scans were conducted at 120 kVp.
Distinct semiconductor to metal transition is observed with the increase of Re and V concentration. Highly conductive V-doped WSe 2 were employed as vertical vdW contact for WSe 2 -FETs. Compared to typical metal contacts using Au and Pd, the on-state current and on/off ratio of WSe 2 -based FETs have been substantially improved from ≈10 –6 ...
1540 °C showed (ref. 3) that the Ir oxidation rate increases significantly when the Re concentration exceeds 20 wt %. From this testing, the Re diffusion into Ir with subsequent oxidation of the resulting Ir-Re alloy was identified as the life-limiting mechanism for Ir/Re rockets, and a 20-wt % Re concentration at the inner wall surface
According to the properties that rhenium and molybdenum can be exchanged to the ion-exchange resin under certain conditions, and desorbed by different desorption agents, we can achieve the purpose of separating molybdenum and rhenium.The results show that: the sample was leached by sulphuric acid, the mass concentration of molybdenum is 19.6% ...
Experimental results indicate that distribution ratio of rhenium increases sharply with increasing amine concentration. Effect of operating phase ratio on the distribution ratio of rhenium shows that as aqueous to organic ratio (A/O) increases from 1 to 15, distribution ratio (DRe) decreases from 48 to 23, for extraction with 1% amine at a pH ...
3 because increasing the concentration of either metal would lead to an increase in the concentration of the complex. The Ni–Re system Rhenium is the 75th element in the periodic table, following tungsten.
The behavior of rhenium and iodine release was comparable within a given half-cell test. The release of iodine and rhenium at 4% moisture content initiated with an initial concentration spike in the sediment immediately contacting the concrete monolith. The concentration profile rapidly decreased to zero within the first 5 cm of the sediment ...
Up to a concentration of 41 wt pct Re, the Charpy ductile-to-brittle transition temperature decreased monotonically with increasing rhenium concentration. Consistent with this, bend angles for fracture at T = -100 C increased monotonically with increasing rhenium concentration.
Assuming the rhenium concentration in molybdenite in the Little Boulder Creek deposit is of the order of 100 to 200 ppm, the mass of rhenium in this deposit is estimated to be from ~2.5 × 10 7 to ~5 × 10 7 grams ... in which case an increase in pH might possibly cause an …
Rhenium is a rare metal with a surprising number of qualities, one of which is a very high boiling point. Rhenium melts at 3459K but remains liquid up to 5903K. ... The sun's surface is 5800-6000K according to sources, so no amount of concentration will increase a blackbody's temperature above that temperature.
a reforming process utilizing as a catlyst a composition of matter comprising a porous solid carrier in association with 0.1 to 3.0 weight percent platinum, and 0.1 to 3.0 weight percent rhenium with a rhenium to platinum atomic ratio of less than 1.0. the platinum and rhenium are disposed on the surface of the carrier by impregnation with water soluble compounds of the metals, followed by ...
The addition of rhenium to molybdenum increases the ductility and raised the recrystallization temperature of. molybdenum with increasing concentration of rhenium. Commercially pure …
Increase of rhenium hexafluoride concentration in the gas mixture lowers the region where heterogene ous reaction runs. Conditions of formation of different types of rhenium precipitates were ...
Superconductive rhenium films were electrodeposited from a water-in-salt type electrolyte with superhigh concentration of LiCl. Rhenium free electrolytes were also studied with linear sweep voltammetry to further understand the effects of LiCl salt concentration on the ion activity and side reactions. ... when the LiCl concentration increases ...
Rhenium-188 (188Re) is a high energy beta-emitting radioisotope with a short 16.9 h physical half-life, which has been shown to be a very attractive candidate for use in therapeutic nuclear medicine. The high beta emission has an average energy of 784 keV and a maximum energy of 2.12 MeV, sufficient to penetrate and destroy targeted abnormal tissues.
Rhenium (Re) is a rare metal (whose average concentration in the Earth's crust is in the order of 1 part per billion) valued for its extremely high melting point. Rhenium is produced by Chile, The Netherlands, Germany, Kazakhstan, the United Kingdom, Poland and the United States; yearly production in 2011 was 49 t [1] .
Notably, rhenium-based compounds have a great potential as theranostics . Indeed, rhenium possesses two isotopes, 186 Re and 188 Re, that have been used in nuclear medicine for more than fifty years . Rhenium use in medicinal pharmaceuticals, radio-imaging and luminescent probes has led to its consideration for use in diagnostic therapy.
That is, there is an improvement in contrast as the concentration of rhenium and iodine is increased from 50 to 200 mM. These findings, which are consistent with other studies [ 57 – 59 ], are depicted graphically in Figure 4(a) for the exposures performed with a 0.6 mm thick copper filter.
Tungsten-rhenium alloys are more ductile at low temperature, allowing them to be more easily machined. The high-temperature stability is also improved. The effect increases with the rhenium concentration, and therefore tungsten alloys are produced with up to 27% of Re, which is the solubility limit.
with rhenium (as perrhenate) shows that after one week the concentration of rhenium increases from 1μg/g in soils to 20 μg Re per 1 g of raw leaves (respectively to 1667 μg Re per 1g ash). In three weeks, the rhenium content in leaves increased up to 110 μg Re per g of raw leaves (respectively up to
increases exponentially, however at temperature over 450 ºC reaction between rhenium hexafluoride and hydrogen proceeds throughout the whole volume with formation of fine-dispersed powder. The results presented in figure 3 were obtained for rhenium hexafluoride concentration in gas phase
During the last three decades, alloy development for blade applications in gas turbines for stationary and especially aeronautical applications has mainly focused on increasing the content of refractory elements such as Mo, Ta, W, Re and Ru [1,2,3].This has led to improved high temperature creep performance but came with various drawbacks, including increased mass density, higher cost and ...
Up to a concentration of 41 wt pct Re, the Charpy ductile-to-brittle transition temperature decreased monotonically with increasing rhenium concentration. Consistent with this, bend angles for fracture at T = -100 C increased monotonically with increasing rhenium concentration.
1. Carrier Concentration a) Intrinsic Semiconductors - Pure single-crystal material For an intrinsic semiconductor, the concentration of electrons in the conduction band is equal to the concentration of holes in the valence band. We may denote, n i: intrinsic electron concentration p i: intrinsic hole concentration However, n i = p i Simply, n
alloying elements was rhenium. Rhenium concentration in second-generation nickel-based superalloys reaches 3–4% by mass, and in the alloys of the third-generation rhenium concentration increases up to 5–6% by mass [1,2]. Presently, nickel-based superalloys containing 9–12% Re are being devel-oped [3].
The total rhenium concentration decreased with increasing irradiation time with a rate constant of 1.91 mM h −1. After 6 h, the total rhenium concentration was below the detection limit (6 μM), indicating that virtually all of the initial rhenium atoms were removed from the reaction solution.
Adding rhenium to molybdenum increases the ductility as the rhenium concentration increases. The primary deformation mechanism of Mo47.5 Re alloys is twinning. Twinning occurs during cold and warm working, enhancing the mechanical properties without sacing ductility yet maintaining good strength at elevated temperatures.
substantial increasing of rhenium concentration in the central cha mber solution ... increased and reached a concentration of 74,24 g /l. Table shows the material balance of rhenium.
A sharp drop in creep strength is observed, if the Re concentration is lowered below 2.3 wt.%. This leads to the optimal concentrations of c Re =2.3 wt.% and c W =3.0 wt.%. (3) High temperature (1373 K): Time to failure steadily increases with (c W +c Re). Similar to 1123 K, two parts of rhenium can be replaced by one part of tungsten.
