The Effect of pH on Stability of an Isolation Barrier Made of Dolomite Post-Floatation Waste

Dolomite post-floatation waste has been proposed as an alternative material for the construction of separation barriers. The aim of this study was to determine the effect of the pH of leaching solutions on the stability of such barriers. The present research included the determination of selected physical and chemical properties of waste, i.e., density, grain composition, and filtration coefficient. Column tests of leaching by solutions of different pH values modeling varying environmental conditions were performed. Selected ions were determined in the eluates. Grain analyses were carried out for the column material after leaching to determine the changes in grain composition of dolomite due to washing with leaching solutions. The determined value of the filtration coefficient is 6.52 × 10−9 m∙s−1, which confirms the impermeability of the waste. The material is fine-grained, with a grain diameter of d ≤ 200 µm. During leaching, a decrease in the content of the analyzed ions and the diameter of grains and their movement down the barrier, resulting in its sealing, was observed. The central part of all columns showed more grains with a diameter of 7 μm, which is probably due to secondary precipitation of CaSO4. Irrespective of the initial pH of the leaching solution, the reaction of all eluates obtained was slightly alkaline (pH 7.52–8.20). Dolomite post-floatation waste has properties that ensure the tightness and durability of the separation barrier, which, combined with its ability to alkalize solutions and the sealing process, ensures its effectiveness.

Subcutaneously Delivered Nano-Insulin Drug as Label Free Nanotheranostic

In this study, it has aimed to understand the relationship between purified insulin and insulin receptor, also nanoinsulin and insulin receptors. The insulin receptor has separated from rat liver using a cryogel column material that is photosensitively insulin cross-linked in the Fast Protein Liquid Chromatography (FPLC) system based on the affinity between insulin and insulin receptor. In the second step, an isolated insulin receptor has used to synthesize insulin receptor cross-linked cryogels for purifying insulin from rats. Subcutaneously delivered nano-insulin drug has prepared from the purified insulin using AmiNoAcid (monomer) Decorated and Light Underpinning Conjugation Approach (ANADOLUCA) method. Lastly, Reflectometric Interference Spectroscopy (RIfS) study has performed to understand the interaction between purified insulin receptor and purified insulin, commercial insulin analog, and nano insulin. These studies have demonstrated that nano-insulin drugs can be effectively used as a theranostic platform to monitor affinity and blocking interactions of nanoprotein drug and its receptor.

TiO2 Decorated Low-Molecular Chitosan a Microsized Adsorbent for a 68Ge/68Ga Generator System

We report column material for a 68Ge/68Ga generator with acid resistance and excellent adsorption and desorption capacity of 68Ge and 68Ga, respectively. Despite being a core element of the 68Ge/68Ga generator system, research on this has been insufficient. Therefore, we synthesized a low molecular chitosan-based TiO2 (LC-TiO2) adsorbent via a physical trapping method as a durable 68Ge/68Ga generator column material. The adsorption/desorption studies exhibited a higher separation factor of 68Ge/68Ga in the concentration range of HCl examined (0.01 M to 1.0 M). The prepared LC-TiO2 adsorbent showed acid resistance capabilities with >93% of 68Ga elution yield and 1.6 × 10−4% of 68Ge breakthrough. In particular, the labeling efficiency of DOTA and NOTA, by using the generator eluted 68Ga, was quite encouraging and confirmed to be 99.65 and 99.69%, respectively. Accordingly, the resulting behavior of LC-TiO2 towards 68Ge/68Ga adsorption/desorption capacity and stability with aqueous HCl exhibited a high potential for ion-exchange solid-phase extraction for the 68Ge/68Ga generator column material.

Taphonomic Implications of a Crinoid from Echinoderm-Poor Lithofacies in the Upper Ordovician (Katian: Cincinnatian) of Northern Kentucky

Crinoids (Phylum Echinodermata) represent major components of fossil assemblages in the type Cincinnatian (Upper Ordovician: Katian) of the greater Cincinnati Arch region. However, certain shallow marine lithofacies are characterized by a nonexistent to depauperate crinoid fauna, being instead dominated by trilobites, bryozoans, mollusks, and in some layers solenoporid algae? and stromatoporoids. One such setting is represented by the Grant Lake Formation, equivalent to the upper Corryville and Mount Auburn members of the McMillan Formation of Ohio, as exposed south of Flemingsburg, Fleming County, northern Kentucky. Described herein is an articulated crinoid crown (Anomalocrinus?) from this otherwise crinoid-poor interval. This occurrence may reflect either (1) a brief interval where conditions were more amenable to occupation by crinoids, possibly corresponding to a minor flooding surface, or (2) transportation of skeletal remains from nearby, deeper offshore areas that contained crinoids in greater abundance. The second interpretation seems more likely given the absence of in situ attachment structures and rarity of disarticulated column material at the study site. This study illustrates the value of echinoderm remains in paleoenvironmental analysis, the significance of crinoidal material in taphonomic interpretation of Paleozoic argillaceous carbonate deposits, and the sensitivity of crinoid fossils as indicators of allochthony or autochthony.

Development of methods for the preparation of radiopure 82Se sources for the SuperNEMO neutrinoless double-beta decay experiment

A radiochemical method for producing82Se sources with an ultra-low level of contamination of natural radionuclides (40K, decay products of232Th and238U) has been developed based on cation-exchange chromatographic purification with reverse removal of impurities. It includes chromatographic separation (purification), reduction, conditioning (which includes decantation, centrifugation, washing, grinding, and drying), and82Se foil production. The conditioning stage, during which highly dispersed elemental selenium is obtained by the reduction of purified selenious acid (H2SeO3) with sulfur dioxide (SO2) represents the crucial step in the preparation of radiopure82Se samples. The natural selenium (600 g) was first produced in this procedure in order to refine the method. The technique developed was then used to produce 2.5 kg of radiopure enriched selenium (82Se). The produced82Se samples were wrapped in polyethylene (12 μm thick) and radionuclides present in the sample were analyzed with the BiPo-3 detector. The radiopurity of the plastic materials (chromatographic column material and polypropylene chemical vessels), which were used at all stages, was determined by instrumental neutron activation analysis. The radiopurity of the82Se foils was checked by measurements with the BiPo-3 spectrometer, which confirmed the high purity of the final product. The measured contamination level for208Tl was 8–54 μBq/kg, and for214Bi the detection limit of 600 μBq/kg has been reached.

A thixotropic supramolecular metallogel with a 2D sheet morphology: iodine sequestration and column based dye separation

A lamellar thixotropic supramolecular metallogel (Mg@DEOA) with a 2D sheet morphology as an adsorbent/separating column material for iodine and water soluble organic dyes.

Settlement Behaviour of Soft Soil Reinforced with Geogrid Encased Stone Column under Sustained Loading

The use of stone columns in improving the bearing capacity of soft soil is well researched, but the understanding of settlement requires further studies. This paper presents the results of a series of laboratory tests carried out to study the settlement behavior of soft soil bed reinforced with ordinary stone column (OSC) and Geogrid encased stone columns (GESC). Kaolin was used as the soft soil and stones of size from 2.5 to 10 mm were used as column material. The stone columns of four different diameters were installed, by the method of replacement, into the soil having undrained shear strength of 22.5 kPa. The OSC and GESC test beds were subjected to pressure of 250 and 300 kPa. Each pressure was sustained for 24 hours and the settlement of the composite soil with time was noted. It is found that Geogrid encased stone columns have small settlement than the corresponding ordinary stone columns. The SRR (settlement reduction ratio) being a measure of ground improvement, is found increasing with the area replacement ratio. Further, at a particular sustained pressure SRR is found more for GESC than the corresponding value for OSC.

Investigation of a tellurium-packed column for isolation of astatine-211 from irradiated bismuth targets and demonstration of a semi-automated system

Astatine-211 is an attractive radionuclide for use in targeted alpha therapy of blood-borne diseases and micrometastatic diseases. Efficient isolation methods that can be adapted to robust automated 211At isolation systems are of high interest for improving the availability of 211At. Based on the early studies of Bochvarova and co-workers involving isolation of 211At from irradiated thorium targets, we developed a method for 211At isolation from bismuth targets using tellurium-packed columns. Dissolution of irradiated bismuth targets is accomplished using HNO3; however, 211At is not captured on the Te column material in this matrix. Our method involves slow addition of aqueous NH2OH·HCl to the Bi target dissolved in HNO3 to convert to a HCl matrix. The amount of NH2OH·HCl was optimized because (1) the quantity of NH2OH·HCl used appears to affect the radiolabeling yield of phenethyl-closo-decaborate(2-) (B10)-conjugated antibodies and (2) reducing the volume of NH2OH·HCl solution can effectively shorten the overall isolation time. A proof-of-concept semi-automated process has been demonstrated using targets containing ~0.96 GBq (~26 mCi) of 211At. High isolation yields (88–95%) were obtained. Radiochemical purity of the isolated 211At was assessed by radio-HPLC. Concentrations of Bi and Te contaminants in the 211At and the astatinated antibodies were evaluated using ICP-MS.