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Abstract

In the present investigation a cylindrical electrostatic precipitator was built into a cyclone's outlet tubes, and was tested at various dusts and voltages. It has been found that the penetration (the unremoved fraction of the dust) for the airborne particles (d < 10 mm) in the case of working built in electrostatic precipitator, decreased to 5–10% of the penetration of the (only) mechanical cyclone operation. The penetration data is given at various dusts and voltages. All are proving that the method is working satisfactorily. If the voltage was smaller than the on set voltage of the discharge, the better performance could be observed. It means that with electric field it is possible to utilize the tribo-charge of the dust particles caused by the collision with the wall of the cyclone.

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Abstract  

The efficiency of two types of cyclones for three ash granulometric classes /0–40, 40–80 and 80–100 m/ was studied with the aid of51Cr radiotracer.

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Abstract  

Two cyclotrons are being operated at IPEN-CNEN/SP: one model CV-28, capable of accelerating protons with energies up to 24 MeV and beam currents up to 30 mA, and three other particles; the other one, model Cyclone 30, accelerates protons with energy of 30 MeV and currents up to 350 mA. Both have the objective of irradiating targets both for radioisotope production for use in nuclear medicine and general research. The development of irradiating systems completely automatized was the objective of this work, always aiming to reduce the radiation exposition dose to the workers and to increase the reliability of use of these systems.

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Abstract  

In the present study, ytterbium-169 was produced via the 169Tm(p, n)169Yb nuclear process at the AMIRS (Cyclone-30, IBA, Belgium) cyclotron, irradiating Tm2O3 with proton particles of 15 MeV primary energy and 20 μA current for 20 min. Deposition of Tm2O3 on Cu substrate was carried out via by the sedimentation method. The 543 mg of thulium(III)oxide with 108 mg of ethyl cellulose and 8 mL of acetone were used to prepare a Tm2O3 layer of 11.69 cm2. Yields of about 0.643 MBq 169Yb per μAh were experimentally obtained. 169Yb was separated in 80 ± 5% radiochemical yield using liquid–liquid extraction. Solvent extraction of no-carrier-added 169Yb from irradiated thulium(III)oxide target hydrochloric solution was investigated using di-(2-ethylhexyl)phosphoric acid (HDEHP).

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Impacts of macrosynoptic weather patterns on the development of the thermal excess in suburban areas of Debrecen are examined in this paper. Temperature datasets have been recorded at two heights by three automatic weather stations mounted in Debrecen (east Hungary) and a small settlement in its vicinity. An additional automatic weather station is used as a reference station outside Debrecen. Urban heat island (UHI) intensities have been calculated from the raw datasets. Impacts of synoptic conditions have been analyzed on the base of Péczely’s macrosynoptic types. It has been found that anticyclone types are more favorable from the aspect of UHI development, while cyclone types, especially the passage of warm fronts can effectively hinder the formation of strong heat islands in Debrecen.

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Abstract  

A thermogravimetric method based on dynamic heating and the use of an internal source of SO2 (metal sulfates with a suitable range of decomposition temperatures) was used to compare the SO2-binding abilities of various lime-containing materials. By means of this method, furnace and cyclone ashes formed in the combustion of oil-shale in the Baltic Power Station, their differently activated (grinding, hydrating) forms and some carbonaceous materials were investigated to estimate their suitability for exhaust gas purification in thermal power stations.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
Mahdi Sadeghi
,
Milad Enferadi
,
Mohammadreza Aboudzadeh
, and
Parvin Sarabadani

Abstract  

This article presents, 122Sb (T 1/2 = 2.723 days, I β- = 97.59%) was produced via the natSn(p,xn) nuclear process at the AMIRS (Cyclone-30, IBA, Belgium). The electrodeposition experiments were carried out by potassium stannate trihydrate (K2Sn(OH)6) and potassium hydroxide. The optimum conditions of the electrodeposition of tin were as follows: 40 g/L natSn, 20 g/L KOH, 115 g/L K2Sn(OH)6, DC current density of 5 A/dm2 with a bath temperature of 75 °C. The electroplated Tin-target was irradiated with 26.5 MeV protons at current of 180 μA for 20 min. Solvent extraction of no-carrier-added 122Sb from irradiated Tin-natural target hydrochloric solution was investigated using di-n-butyl ether (C8H18O). Yields of about 3.61 MBq/μAh were experimentally obtained.

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Abstract  

Use of a short rotary kiln with a cyclone preheater allowed the internal recirculation of volatile constituents, essentially consisting of compounds of potassium, chlorine and sulphur. These compounds underwent partial condensation on the raw material grains, composed mainly of calcite. The increasing concentration of volatile constituents created convenient conditions for the crystallization of new phases, particularly sylvite. Beautiful crystals of this phase were formed, probably by the VLS mechanism. Thermal analysis revealed that a liquid phase was formed in the system at the relatively low temperature of about 630C, which enhanced the reaction of silica with calcium carbonate, and spurrite was formed. Thus, the build-ups were composed mainly of calcite, sylvite and spurrite, and in some cases also of calcium oxide and anhydrite. Sulphospurrite, gehlenite, calcium langbeinite, dicalcium silicate and calcium aluminate, 12CaO7Al2O3 were found as minor components.

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Abstract  

The chemical composition of aerosols emitted during coal combustion was studied as a function of particle size down to 0.01 m. The aerosol collections were carried out in a 81 MW capacity boiler that burned Venezuelan coal in a circulating fluidized bed combustion chamber. The samples were analyzed with upstream of the electrostatic precipitator using a Berner low-pressure impactor, which was quipped with a cyclone pre-cutter to avoid overloading of the first impaction stages. The samples were analyzed by INAA for up to about 40 elements. The elemental concentrations in the particulate matter for each impaction stage were plotted as a function of stage number (particle size). For the elements Na, Al, K, Ca, Sc, Ti, V, Ga, La and Sm, the concentration variation was limited to a factor of 2 to 4, and the concentrations of these elements were lower for the initial and final impactor stages than for the intermediate particle sizes. The variations were also limited to a factor of 2–4 for Mn, Fe, As, Sb and Th, butall these elements showed increasing concentrations with decreasing particle size. Still other elements, such as Ni, Cr, Co, Za, W, Mo and the halogens, were highly enriched (up to 20–100 fold) in the fine particles when compared with the coarse particles.

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Abstract  

Negative health effects of uranium taken into the human body are related to both the chemical toxicity of the metal and its radioactivity. A simple and reliable isotope dilution ICP-MS uranium bioassay technique was developed in this study. Use of this technique at Los Alamos National Laboratory has not been previously described. Dilute urine was introduced to a Perkin Elmer DRC II quadrupole ICP-MS via a PFA high solids nebulizer and a PFA cyclonic spray chamber cooled to 2 °C. Urine samples acidified, digested, and diluted 5× generate a solution that is roughly 10% HNO3 that can be analyzed by ICP-MS to measure uranium concentrations >54 pg/mL and uranium isotopic ratios with high enough precision and accuracy to determine if the uranium in a urine sample is natural. A three-stage rinsing routine is run between each sample to minimize urine salt deposition and uranium memory effects. Regular use of this rinsing routine minimizes instrumental drift and has produced a running 238U background of <7 cps.

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