Precision and accuracy of radiotracer measurements of marine sand flow rates

In radiotracer measurements of the flow rate of marine surface sands, the chief difficulty is to determine the average thickness of the radiotracer spot. The simultaneous use of two detectors may appreciably reduce the uncertainty in the final result.     

Treatment and labeling of silica sand for obtaining a prospective solid 99mTc radiotracer

Journal of Radioanalytical and Nuclear Chemistry - Pretreated silica sand labeling using varying concentrations of tin(II) fluoride and chloride as reducing agents and different times labeling was...     

γ-Alumina-supported boron trifluoride: Catalysis, radiotracer studies and computations

The irreversible adsorption of boron trifluoride on calcined γ-alumina and amorphous chromia, in both cases at room temperature, has been studied using [¹⁸F]-labelled BF₃. Although the resulting γ-alumina surface has some catalytic activity for the room temperature fluorination by anhydrous HF of CH₃CCl₃ under static conditions, its activity is far lower than that of γ-alumina, which has been fluorinated with SF₄, nominally at room temperature. A possible explanation for the observed behaviour is given.     

Use of radiotracer in adsorption studies of copper on peat

In this work copper adsorption by peat was studied using ⁶⁴Cu as tracer considering kinetic and thermodynamic aspects of the process. The study was carried out in agitated batch experiments with copper ion solutions with different initial concentrations at pH 4.5. Adsorption isotherms determined from equilibrium experiments by fitting experimental data to the Langmuir equation showed good correlations. Data obtained from kinetics experiments were fitted to a pseudo-second order model and also in this case a good correlation was obtained. Some parameters calculated from these studies such as rate constant or peat sorption capacity can be used in the development of a waste treatment process based on peat adsorption in batch or in column. The use of the ⁶⁴Cu radiotracer is presented as a simple, rapid and efficient technique to assess the copper adsorption by the peat. This revised version was published online in August 2006 with corrections to the Cover Date.     

Preparation of radioisotope nanoparticles constructed with Au-ligand framework by self-assembly process for radiotracer

Determination of ²³⁶U/²³⁸U at natural ratios using accelerator mass spectrometry (AMS) requires overall purity of each step in the sample preparation procedures which are complex and include various chemicals. Therefore, the simplification of the procedures is desirable and can be done by implementing other effective separation materials. Among the prospective sorption materials, hydrated titanium dioxides showed promising properties for uranium extraction from various water samples. This paper shows the preparation of several titanium based sorption materials using an organic precursor and their characterization with several techniques in order to analyse crystal structure (XRPD, SEM, HRTEM, SAED) and residues of organic compounds (TG analysis and IR spectroscopy) and to quantify their sorption properties towards uranium. The practical sorption capacity of one of the prepared materials was as high as 260 mg of uranium per gram. AMS measurements showed that it is possible to prepare sufficiently pure titanium dioxides for the determination of ²³⁶U/²³⁸U ratio.     

Albumin metal interaction: A multielemental radiotracer study

Interaction of albumin with no-carrier-added metal radionuclides was studied in multielemental environment using dialysis technique. No-carrier-added ^197mHg, ^199–201Tl, ^199–200Pb, ²⁰⁴Bi and ^204,205Po were produced by irradiating Au target consecutively with ⁷Li and ¹²C beams. Similarly, ⁶¹Cu, ^66–68Ga, ^62,63Zn, ^66,67,69Ge, ^71,72As and ⁷³Se were produced by irradiating cobalt target consecutively with ¹⁶O, ⁷Li and ¹²C projectiles. These no-carrier-added radionuclides were chemically separated from the bulk target before studying their interaction with albumin. It was found that Hg and Ga strongly bind with albumin, whereas Bi, Po, As, and Se do not bind at all with albumin. The binding affinities of Pb, Tl, Cu and Zn radionuclides towards albumin are moderate.     

A new radiotracer method of adsorption studies at metal oxide/aqueous electrolyte interface

Adsorption of inorganic ions at the titania/electrolyte solution interfaces has been studies using a radioisotopic technique. Adsorption evaluated from uptake of radioactivity from the solution is compared with that obtained from sediment radioactivity.     

Preparation of powder cellulose

Powder cellulose was obtained according to the scheme of hydrolysis-bleaching from the wood technical (unbleached) sulfate cellulose. In the first step, from the crude cellulose lignocellulose material was obtained, which in the second step was subjected to delignification by treating with hydrogen peroxide and chlorine dioxide.     

On the applicability of radionuclides emitting low energy X-rays for in situ radiotracer adsorption studies

In this paper, methodology and applicability of the in situ radiotracer “thin gap” method are presented and discussed via some studies of Cr(VI) electroreduction on Pt electrode by measuring the low energy (E = 4.90 keV) X-rays of ⁵¹Cr used for labeling. Two types of scintillators, 2 mm thick β-plastic and 300 μm thick CaF₂(Eu), were tested for nuclear detection. The plastic scintillator cannot be utilized for selective measurement of the soft X-rays emitted by ⁵¹Cr, hence, it does not allow us the estimation of the surface excess of chromium containing species on Pt electrode. In contrast to this, CaF₂(Eu) is suitable for selective detection of low-energy X-rays; therefore, the radioelectrochemical cell equipped with the latter detector provides very promising measuring conditions for the extension of the radiotracer “thin gap” method towards application of the low-energy X-ray emitters.     

Preparation of bone powder for FTIR-ATR analysis: The particle size effect

Fourier transform infrared (FTIR) spectroscopy using attenuated total reflection (ATR) is commonly used for the examination of bone. During sample preparation bone is commonly ground, changing the particle size distribution. Although previous studies have examined changes in crystallinity caused by the intensity of grinding using FTIR, the effect of sample preparation (i.e. particle size and bone tissue type) on the FTIR data is still unknown.This study reports on the bone powder particle size effects on mid-IR spectra and within sample variation (i.e. periosteal, mesosteal, trabecular) using FTIR-ATR. Twenty-four archaeological human and faunal bone samples (5 heated and 19 unheated) of different chronological age (Neolithic to post-Medieval) and origin (Belgium, Britain, Denmark, Greece) were ground using either (1) a ball-mill grinder, or (2) an agate pestle and mortar, and split into grain fractions (>500 μm, 250–500 μm, 125–250 μm, 63–125 μm, and 20–63 μm).Bone powder particle size has a strong but predictable effect on the infrared splitting factor (IRSF), carbonate/phosphate (C/P) ratio, and amide/phosphate (Am/P) values. The absorbance and positions of the main peaks, the 2nd derivative components of the phosphate and carbonate bands, as well as the full width at half maximum (FWHM) of the 1010 cm⁻¹ phosphate peak are particle size dependent. This is likely to be because of the impact of the particle size on the short- and long-range crystal order, as well as the contact between the sample and the prism, and hence the penetration depth of the IR light. Variations can be also observed between periosteal, cortical and trabecular areas of bone. We therefore propose a standard preparation method for bone powder for FTIR-ATR analysis that significantly improves accuracy, consistency, reliability, replicability and comparability of the data, enabling systematic evaluation of bone in archaeological, anthropological, paleontological, forensic and biomedical studies.     

Wideline NMR studies of oriented nylon 66

Wideline NMR techniques have been applied to both singly and doubly oriented specimens of nylon 66. Variations in the spectra obtained are observed for different orientations of the specimens relative to the applied field. These variations demonstrate that the zigzag chain axis is essentially parallel to the draw direction and that motion occurs in all of the sample. The motion is of two types: random in the mobile regions and rotation of segments about the chain axis in the rigid regions.     

Preparation of <Superscript>95m</Superscript>Tc radiotracer

Several procedures for preparation of the ^95mTc radiotracer following irradiation of a thin Mo target with deuterons were tested. The procedures consisting of alkaline-oxidative fusion of the irradiated target in a mixture of Na₂O₂ + NaOH and subsequent liquid–liquid extraction with 2-butanone, and acid decomposition of the target in a mixture of H₂SO₄ + HNO₃ followed by extraction chromatography with PAN-Aliquat 336 composite material appeared suitable for the given purpose.     

猪肉冻干粉中克伦特罗标准物质的制备

对活猪采用大腿肌肉注射法持续给予一定浓度的克伦特罗溶液,饲养至稳定状态后,宰杀取猪肉部分制备猪肉冻干粉中克伦特罗基质标准物质.样品检测参考GB/T 22286—2008《动物源性食品中多种β-受体激动剂残留量的测定》,采用同位素内标液相色谱质谱联用法检测克伦特罗的含量,并对样品中克伦特罗的均匀性和稳定性进行评价.定值采...     

Preparation and optimization of moringa leaf powder for edible purpose

In the current scenario, people are highly concerned regarding their health and constantly desire a healthy and nutritious diet. Moringa oleifera is traditionally known as saijhan or drumstick tree. The plant is native to tropical Asia and thus found in various parts of the country India. Being a nutrient-rich plant, Moringa leaves play a vital role in the treatment of malnutrition. It also has anti-inflammatory, anti-spasmodic, anti-asthmatic, anti-ulcer, hypocholesterolemic, and hypoglycemic properties. Fresh fruits have also been desirable and in growing demand, because of healthy food consumption trends worldwide. The following study was undertaken to provide nutrient-rich food in the busy growing lifestyle. Thus, in this study, preparation and optimization of the Moringa leaf powder have been done. The final product is developed by incorporating Moringa leaf powder into pomegranate juice to prepare a ready-to-serve (RTS) beverage. On the basis of this study, it concluded that 100:2:2.8:0.2 concentration of Pomegranate, Moringa oleifera leaf powder, Sugar, Citric Acid is suitable for the preparation of Ready to Serve Beverage. In this study, proximate analysis and sensory evaluation have been performed to understand the overall acceptability of the final product.     

超声波法制备超细铜粉

在40k Hz超声波作用下,使用以Na BH4作为还原剂的化学还原法制备具有粒径约300 nm~500 nm、产率约为80~90%的超细铜粉,其具有反应温度低反应速率快的优点。最佳制备条件为Cu SO4溶液初始浓度为20 g/L、Na BH4的加入量为1.5 g/L、p H值为11.5、反应温度20~30℃;反应时间20~25 min。通过XPS、XRD、SEM对超细铜粉表面进行检测发现分析表明所制备的超细铜粉呈类球状,其表面有少量Cu2O和Cu(OH)2存在。