Thin Layer Activation Research Articles

Extraction, Paper and Thin layer Chromatography and activity of Curcumin

Curcumin is extensively cultivated as spices and herbal medicines in tropical and sub-tropical countries. Geographical origin is known to significantly determine the quality of the herbs used and, consequently, the safety and efficacy of their products. Curcumin is commercially available as a nutrition supplement as it exhibits various medicinal and nutritional properties. Its essential oil is present upto 7%; with high content of bisabolane derivatives. Curcumin has shown potent antibacterial activity and other pharmacological actions in the past 50 years. Curcumin has been marketed globally as a health supplement mainly for its antioxidant and anti-inflammatory, antibacterial properties. Curcumin possesses antibacterial activity against periodontopathic bacteria and may be a potent agent for preventing periodontal diseases. Possession of useful properties, pharmacological safety and negligible cost make curcumin an attractive agent to explore further for its potential therapeutic applications in various endodontic procedures.

Radioactive tracers in industry: Thin layer activation of carbon-based materials for wear measurement

Thin layer activation (TLA) is already routinely utilised for online wear monitoring of metallic components with the radioisotope concentration (RIC) method for various tribological applications. However, many components in tribological systems are made of carbon-based bulk material (e.g. polymers) or have carbon-based wear resistant coatings (e.g. diamond-like carbon). By utilising the nuclear reaction 12C(3He,x)7Be, TLA can thus be employed in carbon-containing components. To evaluate the applicability of this approach for TLA in combination with the RIC method, three materials EPDM (ethylene propylene diene monomer), PEEK (polyether ether ketone) and DLC (diamond-like carbon), which are vastly utilised in tribology, were activated. Subsequently, the modulus of elasticity and hardness of the activated specimens were measured and evaluated if the material works for TLA. As EPDM developed cracks after the irradiation process, it is regarded to be not applicable for TLA and subsequent wear measurements. While the PEEK material revealed small changes in hardness values compared to non-irradiated samples, the irradiated DLC coating showed no detectable material changes. Both irradiated materials have been applied to representative tribological wear studies, for which the RIC results showed a good correlation with optical wear measurements.

On the viability of wearing evaluation by Thin Layer Activation in the presence of non-occupationally exposed individuals

On the viability of wearing evaluation by Thin Layer Activation in the presence of non-occupationally exposed individuals

Evaluation of inhibition effect of poly vinyl pyrrolidone on corrosion of bronze in simulated acid rain using thin layer activation technique

In the present work development of a suitable nontoxic corrosion inhibitor to control corrosion of bronze in simulated acid rain has been investigated using thin layer activation (TLA) technique. Poly vinyl pyrrolidone (PVP) has been identified as an inhibitor and the inhibition action of PVP has been evaluated at different experimental conditions. The result of the study proved that PVP showed good inhibitive characteristics to control corrosion of bronze in the test solution. Kinetic and thermodynamic parameters of the corrosion inhibition process have been determined. The adsorption of inhibitor on bronze surface obeyed Langmiur adsorption isotherm.

Evaluation of production cross-sections for theranostic 67Cu radionuclide via proton-induced nuclear reaction on 68Zn target

Copper-67 (T1/2 = 61.83 h, Eβ−mean=141 keV, Iβ−total=100%; Eγ = 184.577 keV, Iγ = 48.7%) is a promising radionuclide for theranostic applications especially in radio immunotherapy. However, one of the main drawbacks for its application is related to its limited availability. Various nuclear reaction routes investigated in the last years can result in 67Cu production, although the use of proton beams is the method of choice taken into account in this work. The goal of this work is a revision of the cross-sections aimed at 67Cu yield, which were evaluated for the 68Zn(p,2p)67Cu reaction route up to 80 MeV proton energy. A well-defined statistical procedure, i.e., the Simultaneous Evaluation on KALMAN (SOK), combined with the least-squares concept, was used to obtain the evaluated data together with the covariance matrix. The obtained evaluated data were also compared to predictions provided by the nuclear reaction model codes TALYS and EMPIRE, and a partial agreement among them has been found. These data may be useful for both existing and potential applications in nuclear medicine, to achieve an improvement and validation of the various nuclear reaction models, and may also find applications in other fields (e.g., activation analysis and thin layer activation).

Flow accelerated corrosion rate on carbon steel pipe bend by thin layer activation technique and computational modeling: Under PHWR operating conditions

Carbon Steel (CS) piping plays a vital role in the heat transport circuits of power plants. These pipes undergo excessive degradation in some of the specific locations due to the flow dynamics variation and such corrosion is termed as the flow accelerated corrosion (FAC). The corrosion rate is usually estimated at a specific location based on one of the best available technique known as the Think Layer Activation (TLA) method. In the present study this method was adopted for the estimation of CS pipe corrosion with 50NB Sch 160, bend angle of 58° and 4D bend radius (D-pipe diameter). Irradiated location was chosen based on the turbulence patterns in the bend as mapped by CFD analysis. At the specified location the corrosion rate to be monitored was irradiated with the proton beam of 13.3 MeV energy aiming for the nuclear reaction of Fe56(p,n) Co56. This irradiated specimen was welded to the High Temperature High Pressure (HTHP) loop and operated at 290 °C/87 bar. The chemistry parameters like pH (10.2) and DO (< 5 ppb) in the loop were maintained by suitably adding LiOH and N2H4. Corrosion rate was assessed by measuring the radioactivity decrease due to corrosion. Throughout the experimental duration the radioactivity measurement was carried on the CS pipe surface at the fixed distance locations. The flow structure in the considered geometry is simulated using CFD. The flow field, velocity, is used to calculate the wall shear stress and mass transfer coefficient. The corrosion rate is calculated with the help of Chilton-Calbourn Equation. It is observed that the computed corrosion rate for this CS pipe under this chemistry and geometry conditions was 400um/y which coincides with that of the TLA method.

Activity induced in different rare earth materials using heavy ion oxygen beam; thin layer activation analysis

Activities have been measured in spectroscopically pure rare earth materials viz; Terbium, Thulium and Tantalum, based on the remnant radioactivity induced in the material, when bombarded by 16O beam in the energy range from 70 MeV to 110 MeV. The cross sections of a number of isotopes populated through various reaction channels have been measured by the stacked foil activation technique. To measure the activity, yields of the radioactive isotopic products 172,171,170Ta, 171,170Hf, 171,170, 169Lu, 182,181Ir, 182,181Os, 181Re, 194,193,192Tl, 193, 192Hg, and 192,191,190Au have been determined using the measured cross-sections and subsequently used to measure the activity in these materials which has been found up to 8–16 μm.

Evaluation of anti-wear properties of automobile lubricant with different additives using thin layer activation technique

Thin layer activation technique (TLA) has been used for measurement of wear rate of disc gears under lubricated condition. A synthetic base lubricant was blended with four different types of additives, such as, hexagonal boron nitride (h-BN), molybdenum disulphide (MoS2), graphite and copper nanoparticles (Cu np). The wear rate of the disc gear was measured in presence of individual lubricant formulations. The aim of the current study is to examine the effect of different additives on anti-wear behavior of the synthetic heavy duty gear lubricant using TLA technique. The lubricant formulation containing h-BN showed best anti-wear property among all the formulations and the wear rate in this case was found to be minimum from all other cases.

Increasing analyzable steel thickness for thin layer activation experiments

The thin layer activation technique (TLA) is very effective in wear analysis for tribological systems where disassembly is costly or impractical. Since its development in the 1970s, TLA has been applied through direct irradiation of solid targets using ionizing particle beams to obtain an activation with a specific profile. This profile is then used to measure wear in a variety of experiments. These experiments rely heavily on how deep the normalized activation occurs. Depths of $$30\,\upmu {\text{m}}$$ to $$50\,\upmu {\text{m}}$$ are obtained for constant activation by the standard method, which for many experiments is sufficient. However, many others would benefit greatly from a $$300\,\upmu {\text{m}}$$ constant activation layer, such as high-performance engines, softer alloys (brakes), and oil transport systems. Achieving this aim was the goal of this paper. First, we needed to find an adequate irradiation line for the TLA technique. Then, another technique/system was developed (the Attenuation Wheel), which would bring the depth of constant activation from $$50\,\upmu {\text{m}}$$ to $$300\,\upmu {\text{m}}$$.

Investigation of effect of an amine inhibitor on corrosion of carbon steel by using thin layer activation technique

In the present investigation, thin layer activation technique has been employed to study the effectiveness of an amine derivative compound, namely hexamethylene tetramine (HMTA) for corrosion inhibition of carbon steel in acid solution. The corrosion studies have been performed in 1 mol dm−3 HCl containing different concentrations of inhibitors. Inhibition efficiency of HMTA at different experimental conditions has been estimated. It was observed that at ambient condition, 500 ppm HMTA effectively inhibits acid corrosion of carbon steel with an inhibition efficiency of 89.8%. The inhibition efficiency was found to be altered by increase in the temperature of corrosive solution.

Thin Layer Activation analysis in 16O + 169Tm system at low energies

Abstract In this paper authors have explored the use of Thin Layer Activation in a material formed by the irradiation of heavy ion beams on the particular target of interest and its further applications from industrial point of view. Activity depth distributions resulting from the irradiation of Thulium-169 by heavy ion Oxygen-16 beams have been calculated. A pre-calibrated high purity germanium detector was used for radioactive counting of samples. The measured cross-sections for different radio-isotopes have been used to deduce the practical yields for several reaction products; 182, 181Ir, 182, 181Os, 181, 178Re, 175Hf, 172Lu from the intensity of characteristic γ-lines at different energies of 16O beam in the energy range≈ 70-100 MeV employing stacked foil activation technique. Calibration curves obtained from various reaction products have been determined with the help of yield curves. The main purpose of this work is to study the surface wear with increased sensitivity by applying heavy ion in thin layer activation technique.

Activity measurement in Terbium-159 material using heavy ion beams

Abstract Experiment has been performed to study the activity produced in the irradiation of Terbium-159 material with Oxygen-16 heavy ion beams using thin layer activation technique. The yields of reaction products 172,171,170Ta, 171,170Hf and 171,170,169Lu populated via various reaction channels have been measured in the Coulomb barrier to the well above it. A pre-calibrated high purity germanium detector has been used for γ-counting of material. The yield curves obtained from the study of intensity of characteristics γ-lines at different energies of heavy ion beam have been further used to determine the calibration curves of the obtained reaction products. An attempt has been made to study surface wear in terbium by applying heavy ion thin layer activation technique with increased sensitivity

Application of thin layer activation technique for monitoring corrosion of carbon steel in hydrocarbon processing environment

Acidic crude oil transportation and processing in petroleum refining and petrochemical operations cause corrosion in the pipelines and associated components. Corrosion monitoring is invariably required to test and prove operational reliability. Thin Layer Activation (TLA) technique is a nuclear technique used for measurement of corrosion and erosion of materials. The technique involves irradiation of material with high energy ion beam from an accelerator and measurement of loss of radioactivity after the material is subjected to corrosive environment. In the present study, TLA technique has been used to monitor corrosion of carbon steel (CS) in crude oil environment at high temperature. Different CS coupons were irradiated with a 13 MeV proton beam to produce Cobalt-56 radioisotope on the surface of the coupons. The corrosion studies were carried out by subjecting the irradiated coupons to a corrosive environment, i.e, uninhibited straight run gas oil (SRGO) containing known amount of naphthenic acid (NA) at high temperature. The effects of different parameters, such as, concentration of NA, temperature and fluid velocity (rpm) on corrosion behaviour of CS were studied.

Investigation of activation cross sections of proton induced reactions on rhodium up to 70 MeV for practical applications

Excitation functions were measured for production of the $^{113,111,110}$Sn, $^{115m,114m,113m,112m,111g,110g}$In and $^{111m,109}$Cd radioisotopes by bombardment of In targets with proton beams up to 70 MeV, some of them for the first time. The new results are compared with the earlier experimental data and with the theoretical data in the TENDL-2014 (Talys1.6 based) library. Thick target yields were deduced and application of the new data for production of medically relevant $^{110m}$In, $^{111g}$In, $^{113m}$In and $^{114m}$In, as well as applicability for thin layer activation (TLA) are discussed.

Modeling Thin Layer Drying Kinetics, Moisture Diffusivity and Activation Energy of Hazelnuts during Microwave-Convective Drying

Abstract The effects of microwave-convective drying as an efficient drying method, on drying kinetics of hazelnuts were studied. Drying experiments were conducted at three temperature (40, 50 and 60°C) and microwave power (0, 450 and 900 W) levels. The moisture ratio and the temperature of the hazelnuts were recorded during the drying. The results showed that microwave power had a more dominant effect than drying air temperature. Mathematical modeling was performed in order to predict the moisture changes during drying process. It was concluded that two term and Midilli et al. models were the best models to predict the drying kinetics of hazelnut in different conditions. The effective moisture diffusivities varied from 3.80327×10‒8 to 1.71233×10‒6 m2/s and had an increasing polynomial relationship with temperature and microwave power. The activation energy was also between 15.61675 and 41.0053 kJ/mol with a second-order relationship with microwave power.

Investigation of anti-wear performance of automobile lubricants using thin layer activation analysis technique

An investigation was carried out to examine the anti-wear behavior of automobile lubricants using thin layer activation analysis technique. For this study disc gears made of EN 31 steel were labeled with a small amount of radioactivity by irradiating with 13MeV proton beam from a particle accelerator. Experiments on wear rate measurement of the gear were carried out by mounting the irradiated disc gear on a twin-disc tribometer under lubricated condition. The activity loss was monitored by using a NaI(Tl) scintillation detector integrated with a multichannel analyzer. The relative remnant activity was correlated with thickness loss by generating a calibration curve. The wear measurements were carried out for four different types of lubricants, named as, L1, L2, L3 and L4. At lower load L1 and L4 were found to exhibit better anti-wear properties than L2 and L3, whereas, L4 exhibited the best anti-wear performance behavior than other three lubricants at all the loads and speeds investigated.

Measurement of Seawater Flow-Induced Erosion Rates for Iron Surfaces using Thin Layer Activation Technique

The laboratory-scale erosion-corrosion testing facility at BATAN’s Center for Radioisotope and Radiopharmaceutical Technology (PTRR) in Serpong was employed to simulate flow-induced corrosion of iron surfaces. Surface loss rates were measured by a nuclear technique called thin layer activation (TLA) analysis. A 10-MeV proton beam generated from a typical CS-30 cyclotron was used to produce 56 Co radionuclide layers on iron surfaces via a 56 Fe(p,n) 56 Co nuclear reaction. The labeled iron specimens were then exposed to circulating seawater simulated in BATAN’s flow-induced corrosion test facility. The experimental results indicated that the TLA technique was able to measure a very low flow-induced erosion rate of 0.91±0.3 µm/hr. There was no significant difference in the measured surface loss rates between the remaining activity method and the concentration method. The iron surface loss in seawater was lower than that of the same material in HCl solution observed in earlier studies.

THE MECHANICAL COMPONENTS WEAR LEVEL TEST USING THE THIN LAYER ACTIVATION TECHNIQUE

This study discusses about the thin layer activation technique to test the mechanical components wear level. The results of preliminary experimental techniques are presented. The experimental results of the technique by using a motorcycle ring samples showed that the accuracy of measurement of the wear is 8 mg. This means that it will be less precise for testing the lightweight components. It will be more eligible to the component that the weight is more than 220 g. The prospect of developing the technique was also discussed; the result is that this technique would be appropriate to be developed at the DECY-13 cyclotron facility that will soon be constructed in BATAN

Activation cross-sections of proton induced reactions on vanadium in the 37–65 MeV energy range

Experimental excitation functions for proton induced reactions on natural vanadium in the 37–65MeV energy range were measured with the activation method using a stacked foil irradiation technique. By using high resolution gamma spectrometry cross-section data for the production of 51,48Cr, 48V, 48,47,46,44m,44g,43Sc and 43,42K were determined. Comparisons with the earlier published data are presented and results predicted by different theoretical codes (EMPIRE and TALYS) are included. Thick target yields were calculated from a fit to our experimental excitation curves and compared with the earlier experimental yield data. Depth distribution curves to be used for thin layer activation (TLA) are also presented.

Investigation of activation cross sections of proton induced reactions on indium up to 70 MeV for practical applications

Excitation functions were measured for production of the 113,111,110Sn, 115m,114m,113m,112m,111g,110gIn and 111m,109Cd radioisotopes by bombardment of In targets with proton beams up to 70MeV, some of them for the first time. The new results are compared with the earlier experimental data and with the theoretical data in the TENDL-2014 (Talys1.6 based) library. Thick target yields were deduced and application of the new data for production of medically relevant 110mIn,111gIn,113mIn and 114mIn, as well as applicability for thin layer activation (TLA) are discussed.