Nuclear Recoil Reactions in Organo-Manganese Compounds. V. —Mn(CO)5 Target Compounds

1971 ◽  
Vol 49 (12) ◽  
pp. 2175-2178 ◽  
Author(s):  
H. Jakubinek ◽  
S. C. Srinivasan ◽  
D. R. Wiles
Keyword(s):  
Thermal Dissociation ◽  
Nuclear Recoil ◽  
Radical Reactions ◽  
High Yield ◽  
Target Molecule ◽  
Product Spectrum ◽  
Rapid Exchange ◽  
Manganese Compounds ◽  
Very High

HMn(CO)5, DMn(CO)5, CH3Mn(CO)5, and C6H5Mn(CO)5 have been irradiated with neutrons and the product spectrum of 56Mn-containing molecules determined. The results show that H56Mn(CO)5 is formed in all cases: 21.0%, 23.6% from HMn(CO)5 and DMn(CO)5 targets, respectively, and 6.9% and 2.1% from CH3Mn(CO)5 and C6H5Mn(CO)5, respectively. Thus the yields are not in accord with the number of H atoms per target molecule. Preliminary experiments show that •*Mn(CO)5 exchanges rapidly with HMn(CO)5 and DMn(CO)5 and very slowly with CH3Mn(CO)5 and C6H5Mn(CO)5. It is deduced that the very high yield of H56Mn(CO)5 in HMn(CO)5 and DMn(CO)5 targets could arise from the rapid exchange, while the lower yields of H56Mn(CO)5 in other targets must likely come from radical reactions following thermal dissociation of the target molecule.

DURIMPHY

Alloy Digest ◽  
2007 ◽  
Vol 56 (2) ◽  
Keyword(s):  
Tensile Strength ◽  
Corrosion Resistance ◽  
Yield Strength ◽  
Physical Properties ◽  
Precipitation Hardening ◽  
Heat Treating ◽  
High Yield ◽  
High Yield Strength ◽  
Precision Alloys ◽  
Very High

Abstract Durimphy is a maraging steel with 1724 MPa (250 ksi) tensile strength and a very high yield strength due to precipitation hardening. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: FE-140. Producer or source: Metalimphy Precision Alloys.

Radioactive Fall-Out Hazards From Surface Bursts of Very High Yield Nuclear Weapons, Sanitized Version

1954 ◽  
Author(s):  
D. C. Borg ◽  
L. D. Gates ◽  
T. A. Gibson ◽  
Pain Jr. ◽  
Jr R. W.
Keyword(s):  
Nuclear Weapons ◽  
High Yield ◽  
Very High

scholarly journals Near quantitative synthesis of urea macrocycles enabled by bulky N-substituent

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yingfeng Yang ◽  
Hanze Ying ◽  
Zhixia Li ◽  
Jiang Wang ◽  
Yingying Chen ◽  
...  
Keyword(s):  
High Efficiency ◽  
Molecular Structures ◽  
High Yield ◽  
Kinetic Control ◽  
High Concentration ◽  
Weak Association ◽  
Quantitative Synthesis ◽  
Thermodynamic Stabilization ◽  
Discrete Structures ◽  
Very High

AbstractMacrocycles are unique molecular structures extensively used in the design of catalysts, therapeutics and supramolecular assemblies. Among all reactions reported to date, systems that can produce macrocycles in high yield under high reaction concentrations are rare. Here we report the use of dynamic hindered urea bond (HUB) for the construction of urea macrocycles with very high efficiency. Mixing of equal molar diisocyanate and hindered diamine leads to formation of macrocycles with discrete structures in nearly quantitative yields under high concentration of reactants. The bulky N-tert-butyl plays key roles to facilitate the formation of macrocycles, providing not only the kinetic control due to the formation of the cyclization-promoting cis C = O/tert-butyl conformation, but also possibly the thermodynamic stabilization of macrocycles with weak association interactions. The bulky N-tert-butyl can be readily removed by acid to eliminate the dynamicity of HUB and stabilize the macrocycle structures.

scholarly journals Multi-curie production of gallium-68 on a biomedical cyclotron and automated radiolabelling of PSMA-11 and DOTATATE

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Helge Thisgaard ◽  
Joel Kumlin ◽  
Niels Langkjær ◽  
Jansen Chua ◽  
Brian Hook ◽  
...  
Keyword(s):  
Radiochemical Purity ◽  
High Yield ◽  
Clinical Use ◽  
Automated Production ◽  
Automated Method ◽  
Gallium 68 ◽  
High Yields ◽  
High Level ◽  
Mev Protons ◽  
Very High

Abstract Background With increasing clinical demand for gallium-68, commercial germanium-68/gallium-68 ([68Ge]Ge/[68Ga]Ga) generators are incapable of supplying sufficient amounts of the short-lived daughter isotope. In this study, we demonstrate a high-yield, automated method for producing multi-Curie levels of [68Ga]GaCl3 from solid zinc-68 targets and subsequent labelling to produce clinical-grade [68Ga]Ga-PSMA-11 and [68Ga]Ga-DOTATATE. Results Enriched zinc-68 targets were irradiated at up to 80 µA with 13 MeV protons for 120 min; repeatedly producing up to 194 GBq (5.24 Ci) of purified gallium-68 in the form of [68Ga]GaCl3 at the end of purification (EOP) from an expected > 370 GBq (> 10 Ci) at end of bombardment. A fully automated dissolution/separation process was completed in 35 min. Isolated product was analysed according to the Ph. Eur. monograph for accelerator produced [68Ga]GaCl3 and found to comply with all specifications. In every instance, the radiochemical purity exceeded 99.9% and importantly, the radionuclidic purity was sufficient to allow for a shelf-life of up to 7 h based on this metric alone. Fully automated production of up to 72.2 GBq [68Ga]Ga-PSMA-11 was performed, providing a product with high radiochemical purity (> 98.2%) and very high apparent molar activities of up to 722 MBq/nmol. Further, manual radiolabelling of up to 3.2 GBq DOTATATE was performed in high yields (> 95%) and with apparent molar activities (9–25 MBq/nmol) sufficient for clinical use. Conclusions We have developed a high-yielding, automated method for the production of very high amounts of [68Ga]GaCl3, sufficient to supply proximal radiopharmacies. The reported method led to record-high purified gallium-68 activities (194 GBq at end of purification) and subsequent labelling of PSMA-11 and DOTATATE. The process was highly automated from irradiation through to formulation of the product, and as such comprised a high level of radiation protection. The quality control results obtained for both [68Ga]GaCl3 for radiolabelling and [68Ga]Ga-PSMA-11 are promising for clinical use.

The effect of seed rate and nitrogen fertilizer on the yield and nutritive value of oat-vetch mixtures

1989 ◽  
Vol 112 (1) ◽  
pp. 57-66 ◽  
Author(s):  
N. Moreira
Keyword(s):  
Nitrogen Fertilizer ◽  
Crude Protein ◽  
Nutritive Value ◽  
High Yield ◽  
Mineral Nutrient ◽  
Yield Response ◽  
N Nutrition ◽  
North East ◽  
Positive Effect ◽  
Very High

SummaryExperiments were conducted on the seed rates of the components of oat-vetch mixtures combined with varying rates of nitrogen fertilizer in a rainfed area of north-east Portugal in 1982–3 and 1984–5.Forage oats grown alone showed a very high yield response to N and rainfall ranging from 30 to 18·2 t D.M./ha, but had a very low crude protein concentration (37–54 g/kg D.M.) and a poor mineral nutrient composition.The increased use of vetch in the seed mixture had a buffering effect on dry-matter (D.M.) yield but this depended very much on crop N nutrition. For N-deficient conditions vetch inclusion increased the D.M. yield and had a strong positive effect on total forage crude protein (CP) and mineral composition. When crop N nutrition was good, very high D.M. yields (> 12 t D.M./ha) were possible using a high proportion of oats, with vetch making a reduced contribution to the yield and nutritive value of total forage.Seed rates suggested in the literature for Mediterranean conditions are adequate for low N inputs and low available soil N, but not for high D.M. yields which can only be obtained by using a higher proportion of oats and adequate N fertilizer.

Mechanical Behavior of Twinning Induced Plasticity Steel Processed by Warm Forging and Annealing

2018 ◽  
Vol 385 ◽  
pp. 21-26
Author(s):  
Wen Wang ◽  
Dan Wang ◽  
Fu Sheng Han
Keyword(s):  
Twip Steel ◽  
Tensile Deformation ◽  
Initial Density ◽  
High Yield ◽  
High Yield Strength ◽  
Density Of Dislocations ◽  
Yield Point Phenomenon ◽  
Increased Strength ◽  
Warm Forging ◽  
Very High

The present study shows that warmly forged and low-temperature annealed twinning induced plasticity (TWIP) steel exhibited very high dislocation density and apparent yield-point phenomenon in addition to very high yield strength. The initial density of dislocations significantly affected the evolution of dislocations during the subsequent tensile deformation. Original high dense dislocations prompted the rapid increase of dislocations, and intensified the complexity of dislocation configurations. All these effects made the twinning deformation weakened but the dislocation deformation enhanced, leading to increased strength but decreased plasticity.

Visible Light-Promoted C–C Bond Formation from Hydroxyaryls in Water

2019 ◽  
Vol 72 (12) ◽  
pp. 978 ◽  
Author(s):  
Dafne Saporito ◽  
Sergio A. Rodriguez ◽  
Maria T. Baumgartner
Keyword(s):  
Visible Light ◽  
Bond Formation ◽  
High Yield ◽  
Reaction Yield ◽  
Halogen Lamp ◽  
One Pot ◽  
Direct Arylation ◽  
Photoinduced Reactions ◽  
Optical Applications ◽  
Very High

An eco-friendly and direct arylation of hydroxyaryls in water using photoinduced reactions with different substrates (1-bromo-2-naphthol, 1-iodo-2-naphthol, N-(2-iodophenyl)acetamide, 5-bromouracil, 2-iodo-N-methylbenzamide, and 2-iodobenzamide) was studied. For example, π-expanded coumarins, compounds with potential optical applications, were synthesized in very high yield, without the use of toxic reagents, in a one-pot reaction. In addition, we demonstrate that the irradiation source (halogen lamp) can be efficiently replaced by an LED without altering the reaction yield.

scholarly journals 188W/188Re Generator System and Its Therapeutic Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
A. Boschi ◽  
L. Uccelli ◽  
M. Pasquali ◽  
A. Duatti ◽  
A. Taibi ◽  
...  
Keyword(s):  
Specific Activity ◽  
Maximum Energy ◽  
Beta Particle ◽  
High Yield ◽  
Generator System ◽  
Therapeutic Applications ◽  
Radioactive Concentration ◽  
Decay Pattern ◽  
Chemical Strategies ◽  
Very High

The188Re radioisotope represents a useful radioisotope for the preparation of radiopharmaceuticals for therapeutic applications, particularly because of its favorable nuclear properties. The nuclide decay pattern is through the emission of a principle beta particle having 2.12 MeV maximum energy, which is enough to penetrate and destroy abnormal tissues, and principle gamma rays (Eγ=155 keV), which can efficiently be used for imaging and calculations of radiation dose.188Re may be conveniently produced by188W/188Re generator systems. The challenges related to the double neutron capture reaction route to provide only modest yield of the parent188W radionuclide indeed have been one of the major issues about the use of188Re in nuclear medicine. Since the specific activity of188W used in the generator is relatively low (<185 GBq/g), the elutedRe188O4-can have a low radioactive concentration, often ineffective for radiopharmaceutical preparation. However, several efficient postelution concentration techniques have been developed, which yield clinically usefulRe188O4-solutions. This review summarizes the technologies developed for the preparation of188W/188Re generators, postelution concentration of the188Re perrhenate eluate, and a brief discussion of new chemical strategies available for the very high yield preparation of188Re radiopharmaceuticals.

Reductions with sulfurated borohydrides. V. Reductions of ketones

1970 ◽  
Vol 48 (15) ◽  
pp. 2366-2371 ◽  
Author(s):  
J. M. Lalancette ◽  
A. Freche
Keyword(s):  
High Temperature ◽  
Carbonyl Group ◽  
Sodium Borohydride ◽  
Room Temperature ◽  
High Yield ◽  
High Yields ◽  
Very High

Ketones can be reduced with sulfurated sodium borohydride. Very high yield (≈90%) of the corresponding alcohol is obtained with the appropriate ratio of ketone and hydride at room temperature. The reaction is much influenced by the steric environment around the carbonyl group. At high temperature (65°) disulfides and tetrasulfides are produced. In some cases the structure of those sulfides have been established. Conjugated ketones can be reduced to the corresponding alcohols with very high yields.

Thermally Regenerative Hydrogen/Oxygen Fuel Cell Power Cycles

1988 ◽  
Vol 110 (2) ◽  
pp. 107-112 ◽  
Author(s):  
J. H. Morehouse
Keyword(s):  
High Temperature ◽  
Fuel Cell ◽  
Energy Production ◽  
Technology Development ◽  
Thermal Dissociation ◽  
Electrical Energy ◽  
Power Cycles ◽  
Electrical Energy Production ◽  
Oxygen Fuel ◽  
Very High

Two thermodynamic power cycles are analytically examined for future engineering feasibility. These power cycles use a hydrogen-oxygen fuel cell for electrical energy production and use the thermal dissociation of water for regeneration of the hydrogen and oxygen. The first cycle uses a thermal energy input at over 2000K to thermally dissociate the water. The second cycle dissociates the water using an electrolyzer operating at high temperature (1300K) which receives both thermal and electrical energy as inputs. The results show that while the processes and devices of the 2000K thermal system exceed current technology limits, the high temperature electrolyzer system appears to be a state-of-the-art technology development, with the requirements for very high electrolyzer and fuel cell efficiencies seen as determining the feasibility of this system.

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