scholarly journals Studies on electrochemical dissolution of sintered molybdenum discs as a potential method for targets dissolution in 99mTc production

2021 ◽  
Author(s):  
Izabela Cieszykowska ◽  
Katarzyna Jerzyk ◽  
Małgorzata Żółtowska ◽  
Tomasz Janiak ◽  
Grażyna Birnbaum
Keyword(s):  
Electrolyte Solution ◽  
Current Density ◽  
Potassium Hydroxide ◽  
Potassium Hydroxide Solution ◽  
Potential Method ◽  
Solution Temperature ◽  
Electrochemical Dissolution ◽  
Molybdenum Powder ◽  
Platinum Cathode ◽  
Total Dissolution

AbstractElectrochemical dissolution of pressed into discs and sintered metallic molybdenum powder with the mass of 712 ± 10 mg (n = 15) in potassium hydroxide solution was studied in detail. The technique was considered to apply for dissolution of irradiated 100Mo target in the 99mTc production. The effect of various parameters, e.g., the concentration of the electrolyte solution, temperature, current density, and surface area of the platinum cathode, was investigated. The shortest time for total dissolution of molybdenum target was 70 min. This result was achieved using an electrolyte solution of 5 M KOH, temperature 55 °C and the current density of 365 mA/cm2.

Formation of Barrier Oxide Film on Lead in Borate Solutions

1994 ◽  
Vol 59 (6) ◽  
pp. 1305-1310 ◽  
Author(s):  
Emad E. Abdel Aal ◽  
Mohamed M. Hefny
Keyword(s):  
Oxide Film ◽  
Current Density ◽  
High Field ◽  
Empirical Relation ◽  
Field Approximation ◽  
Ion Concentration ◽  
Solution Temperature ◽  
Oxide Growth ◽  
Rate Of Growth ◽  
Barrier Type

Galvanostatic anodization of lead in borate solutions reveals that lead can form a barrier type oxide film. The rate of growth, R, fulfils the empirical relation, R = aib within the current density i range from 1.16 .10-4 to 3.19 .10-4 A cm-2. The magnitudes of the parameters a and b are 6.9 . 103 and 1.6, respectively, it has been found that the high field approximation is applicable for the oxide growth on lead. The coefficients of the dependence of R on solution temperature, T, pH and borate ion concentration, c, viz. (∂R/∂T), (∂R/∂pH) and (∂R/∂log c) are -18 . 10-4, -0.13 and 0.41, respectively.

Kinetics and mechanism of cyclization of N-(2-methoxycarbonylphenyl)-N’-methylsulphonamide to 3-methyl-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide

1991 ◽  
Vol 56 (8) ◽  
pp. 1701-1710 ◽  
Author(s):  
Jaromír Kaválek ◽  
Vladimír Macháček ◽  
Miloš Sedlák ◽  
Vojeslav Štěrba
Keyword(s):  
Potassium Hydroxide ◽  
Acid Catalysis ◽  
Potassium Hydroxide Solution ◽  
Hydroxide Solution ◽  
General Base ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Cyclization Kinetics ◽  
Rate Limiting ◽  
Kinetics Of

The cyclization kinetics of N-(2-methylcarbonylphenyl)-N’-methylsulfonamide (IIb) into 3-methyl-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide (Ib) has been studied in ethanolamine, morpholine, and butylamine buffers and in potassium hydroxide solution. The cyclization is subject to general base and general acid catalysis. The value of the Bronsted coefficient β is about 0.1, which indicates that splitting off of the proton from negatively charged tetrahedral intermediate represents the rate-limiting and thermodynamically favourable step. In the solutions of potassium hydroxide the cyclization of dianion of the starting ester IIb probably becomes the rate-limiting step.

scholarly journals Synthesis and characterization of new Oxazine , Thiazine and Pyrazol derived from chalcones

2014 ◽  
Vol 11 (2) ◽  
pp. 477-485 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Nmr Spectroscopy ◽  
Hydrazine Hydrate ◽  
Elemental Analysis ◽  
Potassium Hydroxide ◽  
1H Nmr Spectroscopy ◽  
Room Temperature ◽  
Potassium Hydroxide Solution ◽  
Synthesis And Characterization ◽  
Heterocyclic Derivatives

In this study, chalcones were synthesis by condensing 2-acetylpyridine with aromatic aldehyde derivatives in dilute ethanolic potassium hydroxide solution at room temperature according to Claisen-Schmidt condensation. After that, new heterocyclic derivatives such as Oxazine, Thiazine and Pyrazol were synthesis by reaction between chalcones with urea, thiourea and hydrazine hydrate respectively scheme 1. All these compounds wrer characterization by FTIR, 1H-NMR spectroscopy and elemental analysis.

Effect of Cathode Waste Material Concentration in Conductive Paint Coating

2021 ◽  
Vol 4 (2) ◽  
pp. 78-81
Author(s):  
N.S.W. Zulkefeli ◽  
W.M.I.W. Ismail ◽  
M.K.A.A. Razab ◽  
M.N. Masri
Keyword(s):  
Electromagnetic Interference ◽  
Potassium Hydroxide ◽  
Potassium Hydroxide Solution ◽  
Waste Material ◽  
X Ray Diffraction ◽  
Paint Coating ◽  
X Ray ◽  
Electronic Application ◽  
Before And After ◽  
Conductive Paint

The conductive paint coating can be used to control the electromagnetic interference in electronic application. Conductive paint coating was made by mixing the epoxy and hardener with cathode waste material (CWM) in order to manipulate their properties. In this study, the conductivity and the thickness of the paint has been studied. The thickness of conductive paint coating was depends on the agglomeration of CWM content. The increasing of wt% of CWM, the thickness of paint is increasing. Bruker D2Phaser X-Ray diffraction has been used in order to get the phase analysis of the paint before and after soaking into Potassium Hydroxide solution

New response to sexual characteristics

2021 ◽  
Vol 20 (9) ◽  
pp. 987-987
Author(s):  
V. G.
Keyword(s):  
Potassium Hydroxide ◽  
Sodium Hydroxide Solution ◽  
Potassium Hydroxide Solution ◽  
Test Tube ◽  
Animal Tissues ◽  
Hydroxide Solution ◽  
Sexual Characteristics ◽  
Small Test ◽  
Small Test Tube ◽  
Color Indicator

Prof. Bernatsky (Doctor. Gaz., 1924, No. 18) describes a new specific reaction to the sexual characteristics of plant and animal tissues. 1/4 of the timing is taken. test tissue, crushed in a mortar, placed in a small test tube ("port-fleur"), 1 cube of site is poured, a mixture of equal parts of 0.582% sodium hydroxide solution and 0.816% potassium hydroxide solution, the mixture is thoroughly mixed with a glass rod, and 1 a drop of a color indicator consisting of 2 hours of alcohol (95-96 ) 1% dalpy solution, 1 hour. one

Reactions of tert-Butyl Peroxy Esters, XIV. Further Observations on the Preparation of Dialkyl tert-Butylperoxy Phosphates

1975 ◽  
Vol 30 (9-10) ◽  
pp. 732-739 ◽  
Author(s):  
G. Sosnovsky ◽  
E. H. Zaret
Keyword(s):  
Potassium Hydroxide ◽  
Potassium Hydroxide Solution ◽  
Sodium Hydride ◽  
High Yield ◽  
Butyl Hydroperoxide ◽  
Tert Butyl ◽  
Tert Butyl Hydroperoxide ◽  
Aqueous Potassium Hydroxide ◽  
Butyl Peroxide

The preparation of dialkyl tert-butylperoxy phosphates (2, R = alkyl) has been achieved by the reaction of the corresponding dialkyl phosphorochloridates (1, R = alkyl) with tert-butyl hydroperoxide either in the presence of pyridine or in the presence of aqueous potassium hydroxide solution. Neither of these routes is suitable for the preparation of dialkyl tert-butylperoxy phosphates in quantity since they yield peroxyphosphates which are contaminated either with the corresponding tetraalkyl pyrophosphates or dialkyl phosphates; the contaminants cannot easily be removed by conventional means from the peroxyphosphates. The method of choice for the preparation in high yield of large quantities of pure dialkyl tert-butylperoxy phosphates involves the interaction of the corresponding dialkyl phosphorochloridate with sodium tert-butyl peroxide which has been prepared in situ from the reaction of tert-butyl hydroperoxide with sodium hydride.

Sign in / Sign up

Export Citation Format

Share Document