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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Nonlinear Bounded-Error Target State Estimation Using Redundant States

Covello, James Anthony January 2006 (has links)
When the primary measurement sensor is passive in nature--by which we mean that it does not directly measure range or range rate--there are well-documented challenges for target state estimation. Most estimation schemes rely on variations of the Extended Kalman Filter (EKF), which, in certain situations, suffer from divergence and/or covariance collapse. For this and other reasons, we believe that the Kalman filter is fundamentally ill-suited to the problems that are inherent in target state estimation using passive sensors. As an alternative, we propose a bounded-error (or set-membership) approach to the target state estimation problem. Such estimators are nearly as old as the Kalman filter, but have enjoyed much less attention. In this study we develop a practical estimator that bounds the target states, and apply it to the two-dimensional case of a submarine tracking a surface vessel, which is commonly referred to as Target Motion Analysis (TMA). The estimator is robust in the sense that the true target state does not escape the determined bounds; and the estimator is not unduly pessimistic in the sense that the bounds are not wider than the situation dictates. The estimator is--as is the problem itself--nonlinear and geometric in nature. In part, the simplicity of the estimator is maintained by using redundant states to parameterize the target's velocity. These redundant states also simplify the incorporation of other measurements that are frequently available to the system. The estimator's performance is assessed in a series of simulations and the results are analyzed. Extensions of the algorithm are considered.
212

Target Types and Placement for Terrestrial and Mobile Mapping

Scott M. Peterson (5930144) 03 January 2019 (has links)
The use of digital three-dimensional (3D) data has increased over the last two decades as private and public firms have begun to realize its utility. Mobile Terrestrial Laser Scanning (MTLS) or Mobile Mapping Systems (MMS), which utilizes LiDAR (Light Detection and Ranging) data collection from a moving platform along with advances in positioning systems—e.g., Global Navigation Satellite Systems (GNSS), Inertial Navigation Systems (INS), and Distance Measurement Instruments (DMIs)—have paved the way for efficient, abundant, and accurate 3D data collection. Validation and control targets are vital to ensure relative and/or absolute accuracy for MTLS projects. The focus of this dissertation is to evaluate several types of targets and the positional spacing of said targets for MTLS.<div><br></div><div>A mostly planar two-dimensional (2D) targeting system (painted target on ground) is commonly used to constrain, register, and validate the 3D point clouds from MTLS. In this dissertation, 3D objects—a sphere and a cube—were evaluated with varied angles of incidence and point densities as more appropriate alternatives to constrain and validate the 3D MTLS point clouds. Next, a planar circular 2D target—with the use of the raw intensity of the LiDAR pulse as another measured dimension—was evaluated as a proof of concept to also constrain and validate 3D LiDAR data. A third and final component of this dissertation explored analyses of INS data to determine the positional spacing of control and validation targets in MTLS projects to provide maximum accuracy for all data points.<br></div>
213

Étude des facteurs de transcription impliqués dans la signalisation de l’azote/nitrate / Study of the role of transcription factors involved in nitrogen/nitrate signaling

Safi, Alaeddine 27 March 2018 (has links)
Les plantes prélèvent l’azote nécessaire à leur croissance essentiellement sous forme de nitrate. Pour faire face aux fluctuations spatio-temporelles de la disponibilité de cet ion dans les sols, ces organismes ont développé des mécanismes d’adaptation spécifiques à chaque situation. La réponse de la plante à l’azote met en jeu plusieurs voies de signalisations qui dépendent des scénarios de variations en azote du milieu. Deux grandes voies de signalisation sont étudiées en particulier dans cette thèse. La Primary Nitrate Response (ou PNR) qui correspond aux réponses rapides (minutes) et nitrate-spécifiques de la plante lors de la fourniture de Nitrate. La Nitrogen Starvation response (ou NSR) qui correspond à la réponse plus lente (jours) qui permet de pallier au manque d’azote dans le milieu. Bien que certains acteur moléculaires soient connus dans chacune des voies (PNR et NSR); i) la NSR est largement moins bien documentée que la PNR, ii) rien n’est connu concernant la coordination des 2 voies de signalisations. Au cours de ma thèse j’ai pu démontrer qu’un sous groupe de la famille GARP induit lors de la PNR est directement impliqué dans la régulation de la NSR (répression des gènes de transport à haute affinité de nitrate). Ceci fournit à la fois des nouveaux régulateurs de la NSR et un mécanisme de coordination entre les 2 voies de signalisation. Les phénotypes des plantes altérées dans l’expression des gènes de cette famille de facteurs de transcription ouvrent des perspectives d’améliorations biotechnologiques des plantes car ces dernières présentent des capacités de transport du nitrate bien supérieures aux plantes sauvages.Des résultats quant à la double localisation sub-cellulaire d’HRS1 et du rôle d’HRS1 dans le contrôle du statut redox des plantes sont présentés et discutés dans le contexte du modèle d’interaction entre PNR et NSR proposé précédemment. / Plants take up the nitrogen necessary for their growth mainly in the form of nitrate. To cope with spatio-temporal fluctuations in NO3- availability in soils, these organisms have developed adaptation mechanisms specific to each situation. Plant N response involves several signaling pathways that depend on the N variation scenarios of the medium. Two major signaling pathways are studied in this thesis. The Primary Nitrate Response (or PNR) which corresponds to the rapid (within minutes) and nitrate-specific responses of the plant when provided with Nitrate. The Nitrogen Starvation response (or NSR) which corresponds to the slower response (within days) which makes it possible to overcome the lack of N in the medium. Although some molecular actors are known in each of the pathways (PNR and NSR); i) the NSR is significantly less well documented than the PNR, ii) nothing is known about the coordination of the 2 signaling pathways. During my thesis I was able to demonstrate that a subgroup of the GARP transcription factor family induced during PNR is directly involved in the regulation of NSR (repression of transport genes with a very high nitrate affinity). This provides both new NSR regulators and a coordination mechanism between the 2 signaling pathways. The phenotypes recorded for plants altered in this transcription factors family open up perspectives for crop biotechnological improvements because they have nitrate transport capacities far superior to wild plants.Results regarding the subcellular dual localization of HRS1 and the role of HRS1 in controlling the redox status of plants are presented and discussed in the context of the previously proposed PNR-NSR interaction model.
214

Association of predicted deleterious single nucleotide polymorphisms with carcass traits in meat-type chickens / Associação de polimorfismos de base única preditos como deletérios com características de carcaça em frangos de corte

Priscila Anchieta Trevisoli 11 May 2018 (has links)
Breeding has been the mainly responsible for the increase of poultry efficiency in the last decades. The breeding programs are geared towards higher meat yield and feed efficiency. Among the used genomic approaches, genome wide association studies (GWAS) identified quantitative trait loci (QTLs) associated with carcass traits in a meat-type population (TT Reference Population). GWAS analysis identifies variants in linkage disequilibrium with the possible causal mutation and with the aim of refining these results, association study with missense single nucleotide polymorphisms can be useful. A missense SNP can be predicted as deleterious via Sorting Intolerant From Tolerant (SIFT) score when the amino acid change has the potential to impact the protein function and consequently may affects the phenotype. Therefore, in this study, predicted deleterious SNPs within QTLs regions were identified and associated with thigh, drumstick, abdominal fat and breast weight and their yields. Mixed model was used with sex, incubation and SNPs genotypes as fixed effects and family as random effect. From the 20 SNPs analyzed, six were significantly associated (p <0.05) with weight and yield of thigh, breast and drumstick. Three of them s736010549, rs739508259 and rs313532967 are located in the genes WDR77, VWA8 and BARL, respectively. These genes are involved in biological process as steroid hormone signaling pathway, estrogen binding, and regulation of cell proliferation. We determined these genes as candidates for muscle growth. Our strategy allowed the identification of potential causal mutations associated with muscle growth and development. / O melhoramento genético é o principal responsável pelo aumento da eficiência da produção avícola nas últimas décadas e os programas de melhoramento de aves estão direcionados para um maior rendimento de carne e eficiência alimentar. Dentre as abordagens genômicas, estudos de associação genômica ampla (GWAS) identificaram loci associados com características quantitativas (QTLs) de carcaça em uma população de frangos de corte. Análise de GWAS identifica regiões em desequilíbrio de ligação com possíveis mutações causais e com o objetivo de refinar esses resultados, estudos de associações usando polimorfismos de base única (SNPs) não sinônimos podem ser úteis. O SNP não sinônimo pode ser predito como deletério por meio do Sorting Intolerant From Tolerant (SIFT) score quando a alteração de aminoácidos tem o potencial de impactar a função da proteína e consequentemente pode afetar o fenótipo. Portanto, neste estudo, SNPs preditos como deletérios localizados em regiões de QTLs foram identificados e associados com peso e rendimento de coxa, sobrecoxa, gordura abdominal e peito de frangos de corte. Modelo misto foi utilizado, com sexo, incubação e genótipos dos SNPs como efeitos fixos e família como efeito aleatório. De 20 SNPs analisados, seis foram associados significativamente (p<0,05) com peso e rendimento de coxa, sobrecoxa e peito, e três deles rs736010549, rs739508259 e rs313532967 estão presentes nos genes WDR77, VWA8 e BARL, respectivamente. Estes genes estão relacionados com processos biológicos como via de sinalização de esteroide, receptores de estrogênio e de ácidos biliares. Nossa estratégia permitiu a identificação de potenciais mutações causais associadas com crescimento e desenvolvimento muscular.
215

Association of predicted deleterious single nucleotide polymorphisms with carcass traits in meat-type chickens / Associação de polimorfismos de base única preditos como deletérios com características de carcaça em frangos de corte

Trevisoli, Priscila Anchieta 11 May 2018 (has links)
Breeding has been the mainly responsible for the increase of poultry efficiency in the last decades. The breeding programs are geared towards higher meat yield and feed efficiency. Among the used genomic approaches, genome wide association studies (GWAS) identified quantitative trait loci (QTLs) associated with carcass traits in a meat-type population (TT Reference Population). GWAS analysis identifies variants in linkage disequilibrium with the possible causal mutation and with the aim of refining these results, association study with missense single nucleotide polymorphisms can be useful. A missense SNP can be predicted as deleterious via Sorting Intolerant From Tolerant (SIFT) score when the amino acid change has the potential to impact the protein function and consequently may affects the phenotype. Therefore, in this study, predicted deleterious SNPs within QTLs regions were identified and associated with thigh, drumstick, abdominal fat and breast weight and their yields. Mixed model was used with sex, incubation and SNPs genotypes as fixed effects and family as random effect. From the 20 SNPs analyzed, six were significantly associated (p <0.05) with weight and yield of thigh, breast and drumstick. Three of them s736010549, rs739508259 and rs313532967 are located in the genes WDR77, VWA8 and BARL, respectively. These genes are involved in biological process as steroid hormone signaling pathway, estrogen binding, and regulation of cell proliferation. We determined these genes as candidates for muscle growth. Our strategy allowed the identification of potential causal mutations associated with muscle growth and development. / O melhoramento genético é o principal responsável pelo aumento da eficiência da produção avícola nas últimas décadas e os programas de melhoramento de aves estão direcionados para um maior rendimento de carne e eficiência alimentar. Dentre as abordagens genômicas, estudos de associação genômica ampla (GWAS) identificaram loci associados com características quantitativas (QTLs) de carcaça em uma população de frangos de corte. Análise de GWAS identifica regiões em desequilíbrio de ligação com possíveis mutações causais e com o objetivo de refinar esses resultados, estudos de associações usando polimorfismos de base única (SNPs) não sinônimos podem ser úteis. O SNP não sinônimo pode ser predito como deletério por meio do Sorting Intolerant From Tolerant (SIFT) score quando a alteração de aminoácidos tem o potencial de impactar a função da proteína e consequentemente pode afetar o fenótipo. Portanto, neste estudo, SNPs preditos como deletérios localizados em regiões de QTLs foram identificados e associados com peso e rendimento de coxa, sobrecoxa, gordura abdominal e peito de frangos de corte. Modelo misto foi utilizado, com sexo, incubação e genótipos dos SNPs como efeitos fixos e família como efeito aleatório. De 20 SNPs analisados, seis foram associados significativamente (p<0,05) com peso e rendimento de coxa, sobrecoxa e peito, e três deles rs736010549, rs739508259 e rs313532967 estão presentes nos genes WDR77, VWA8 e BARL, respectivamente. Estes genes estão relacionados com processos biológicos como via de sinalização de esteroide, receptores de estrogênio e de ácidos biliares. Nossa estratégia permitiu a identificação de potenciais mutações causais associadas com crescimento e desenvolvimento muscular.
216

Operating target therapy for cancer drugs, key success factors.

Hung, Kuo-Yao 12 August 2010 (has links)
Abstract Cancer has been a big issue in the medical science. Many scientists in the world have been trying so hard to find the effective drugs or therapies for different kinds of cancers. However, cancer is till so hard to cure. Until these days targeted therapies show up and give cancer patient a new hope to cure cancer. Targeted therapies are drugs which can block the growth and spread of cancer by interfering with specific molecules involved in tumor growth and progression. By focusing on molecular and cellular changes that are specific to cancer, targeted therapies are more effective than other types of treatment, including chemotherapy and radiotherapy, and less harmful to normal cells. Targeted therapies have been known by reducing side effects and improving quality life as well. Therefore, many drug manufactures have been investing money on investigating targeted therapies. Target therapy market is rapidly expending, and the competition among the drug manufactures has been more and fiercer. The key or critical success factors to the business of target cancer drugs are the most important issue for the drug manufactures to get the most profit from target drugs. The key success factors can be analyzed by sell strategy, research, development strategy, price strategy and government policy. This paper is trying to find the key success factors for business of target cancer drugs by deep interviewing the top sells managers in the industry and the top doctors in the hospital. Then these interview contents are analyzed by SWOT (strength, weakness, opportunity and threat) to find the key success factors for business of target cancer drugs. With these key success factors, hopefully it can help the drug manufactures make good business on target cancer drug market. Keywords: target drug, target therapy, key success factor, critical success factor, SWOT, deep interview.
217

Artillery Target Assignment Problem With Time Dimension

Sapaz, Burcin 01 December 2008 (has links) (PDF)
In this thesis, we defined a new assignment problem and named it as the artillery target assignment problem(ATAP). The artillery target assignment problem is about assigning artillery weapons to targets at different time instances while optimizing some objectives. Since decisions at a time instance may affect decisions at other time instances, solving this assignment problem is harder than the classical assignment problem. For constructing a solution approach, we defined a base case and some variations of the problem which reflects subproblems of the main problem. These sub-problems are investigated for possible solutions. For two of these sub-problems, genetic algorithm solutions with customized representations and genetic operators are developed. Experiments of these solutions and related results are presented in this thesis.
218

18F− saturation yield in Large Volume cylindrical IBA target

Leporis, M., Rajec, P., Reich, M., Stefecka, M., Szöllos, O., Kovac, P. 19 May 2015 (has links) (PDF)
Introduction In last decade increasing demand for clinical F-18 Fludeoxyglucose requires a greater F-18 fluoride production. From the other side increasing price of enriched O-18 water compel us to find the most effective way of F-18 activity production. One of the possible way, how to optimize and increase yield of F-18, is to increasing target current with retaining the same or less volume of enriched water. Optimization of F-18 production on IBA Large Volume cylindrical target is presented. Material and Methods Irradiations of [18O]H2O by 18MeV proton beams with intensities 40–55 μA were performed on CYCLON 18/9, IBA cyclotron and on LV cylindrical IBA target. Irradiated enriched water was transported to the hot cell using RDS (Radioactive Delivery System) system and was measured in Curriementor 4 Isotope Calibrator made by PTW. At the beginning it was necessary to satisfy several requirements: i) target and water cooling. Using a simple two dimensional equation we can roughly estimate the equilibrium temperature inside the target [1]: Δt = HT/Ak where: Δt = the temperature rise in the target chamber over cooling water temperature H = is the heat load T = thickness of metal wall A = area of metal in contact with target water k = thermal conductivity In our case with heat load 720 W (40 μA×18 MeV) is Δt = 78 oC. From the curve of boiling point of water as a function of pressure [2], we can observe t = 212 °C at 20 bar or 243 °C at 35 bar, respectively, which corresponds to max. heat load up to 90–95 µA of target current. ii) pressure and filling water volume. Filling water volume was from 2 to 2.15 ml to guarantee stop all beam in water. Also during experiments for safety reasons the operating pressure was limited to 35 bar as the window rupture pressure is > 50 bar for used 0.05 mm Havar foil. In this case increasing target volume with increasing current was provided with longer tube. Results and Conclusion The saturated yields of F-18 for 40 µA to 55 µA target currents are given in TABLE 1. No systematic decrease in yields with increasing target current was observed and yields were in line with the 230 ± 10 mCi/µA measured at acceptance test of target. The [18F]FDG yields from productions using the TRACERlab-Mx module are shown in FIGURE 1. All presented productions of F-18 were prepared with LV target with 55 µA. No decrease in the yield was observed with increasing beam current. It has been demonstrated that it is possible to produce routinely 250 GBq/2hr (6.8 Ci/2hr) of 18F-Fluoride using LV cylindrical target (operating conditions: 55 µA, 18 MeV, 98% enriched water). As the next step we want to test dual beam – 2×55 µA with two LV targets and expected activity about 500 GBq of 18F-Fluoride in 2 hours is expected.
219

Production and isolation of 72As from proton irradiation of enriched 72GeO2 for the development of targeted PET/MRI agents

Ellison, P. A., Chen, F., Barnhart, T. E., Nickles, R. J., Cai, W., DeJesus, O. T. 19 May 2015 (has links) (PDF)
Introduction Two current major research topics in nuclear medicine are in the development of long-lived positron-emitting nuclides for imaging tracers with long biological half-lives and in theranostics, imaging nuclides which have a chemically analogous therapy isotope. As shown in TABLE 1, the radioisotopes of arsenic (As) are well suited for both of these tasks with several imaging and therapy isotopes of a variety of biologically relevant half-lives accessible through the use of small medical cyclotrons. The five naturally abundant isotopes of germanium are both a boon and challenge for the medical nuclear chemist. They are beneficial in that they facilitate a wide array of producible radioarsenic isotopes. They are a challenge as monoisotopic radioarsenic production requires isotopically-enriched targets that are expensive and of limited availability. This makes it highly desirable that the germanium target material is reclaimed from arsenic isolation chemistry. One major factor which has limited the development of radioarsenic has been difficulties in its incorporation into biologically relevant targeting vectors. Previous studies have labeled antibodies and polymers through covalent bonding of arsenite (As(III)) with the sulfydryl group1,2,3. Recent work in our group has shown the facile synthesis and utility of superparamagnetic iron oxide nanoparticle- (SPION-)bound radioarsenic as a dual modality positron emission tomography (PET)/magnetic resonance imaging (MRI) agent4. Presently, we have built upon previous studies producing, isolating, and labeling untargeted SPION with radioarsenic4,5. We have incorp-rated the use of isotopically-enriched 72GeO2 for the production of radioisotopically pure 72As. The bulk of the 72GeO2 target material was re-claimed from the arsenic isolation chemical procedure for reuse in future irradiations. The 72As was used for ongoing development toward the synthesis of targeted, As-SPION-based, dual-modality PET/MRI agents. Material and Methods Targets of ~100 mg of isotopically-enriched 72GeO2 (96.6% 72Ge, 2.86% 73Ge, 0.35% 70Ge, 0.2% 74Ge, 0.01% 76Ge, Isoflex USA) were pressed into a niobium beam stop at 225 MPa, covered with a 25 µm HAVAR containment foil, attached to a water-cooling target port, and irradiated with 3 µA of 16.1 MeV protons for 2–3 hours using a GE PETtrace cyclotron. After irradiation, the target and beam stop were assembled into a PTFE dissolution apparatus, where the 72GeO2 target material was dissolved with the addition of 2 mL of 4 M NaOH and subsequent stirring. After dissolution was completed, the clear, colorless solution was transferred to a fritted glass column and the bulk 72GeO2 was reprecipitated by neutralizing the solution with the addition of 630 µL [HCl]conc, filtered, and rinsed with 1 mL [HCl]conc. To the combined 72As-containing filtrates, 100 µL 30% H2O2 was added to ensure that 72As was in the nonvolatile As(V) oxidation state. The ~3 mL solution was then evaporated at 115 ˚C while the vessel was purged with argon, followed by a second addition of 100 µL H2O2 after the volume was reduced to 1 mL. When the filtrate volume was ~0.3 mL, the vessel was removed from heat, allowed to cool with argon flow, and the arsenic reconstituted in 1 mL [HCl]conc and loaded onto a 1.5 mL bed volume Bio-Rad AG 1×8, 200–400 mesh anion exchange column preconditioned with 10 M HCl. The radioarsenic was eluted in 10 M HCl in the next ~10 mL, with 90% of the activity eluting in a 4 mL fraction. The column was then eluted with 5 mL 1 M HCl. The 72As-rich 10 M HCl fraction was reduced to As(III) with the addition of ~100 mg CuCl, and heating to 60 ˚C for 1 hour. The resulting AsCl3 was then extracted twice into 4 mL cyclohexane, which were combined and back extracted into 500 µL of water as As(OH)3. This solution of 72As in H2O was then used directly to label SPION and for subsequent experiments conjugating 72As-SPION with TRC105, an angiogenesis-marking monoclonal antibody (MAb) targeting endoglin/CD105. Several methods were initially attempted involving directly conjugating the surface-modified SPION to the MAb through a polyethylene glycol (PEG) linker. More recent studies have investigated the radioarsenic labeling of SPION encapsulated in hollow mesoporous silica nanoparticles (SPION@HMSN) and its subsequent conjugation to TRC105. Results and Conclusion Irradiation of pressed, isotopically-enriched 72GeO2 resulted in a production yield for 72As of 17 ± 2 mCi/(µA·hr·g) and for 71As of 0.37 ± 0.04 mCi/(µA·hr·g), which are 64 % and 33 %, of those predicted from literature6, respectively. However, these production yields are in agreement with those scaled from observed production yields using analagous natGeO2 targets. The end-of-bombardment 72As radionuclidic purity can be improved by minimizing the 72Ge(p,2n)71As reaction by degrading the beam energy. A 125 µm Nb containment foil would degrade impinging protons to 14.1 MeV and is predicted to reduce 71As yield by a factor of three, while only reducing 72As yield by 1 %6, improving end-of-bombardment radionuclidic purity from 98 % to greater than 99 %. Overall decay-corrected radiochemical yield of the 72As isolation procedure from 72GeO2 were 51 ± 2 % (n = 3) in agreement with those observed with natGeO2 57 ± 7 % (n = 14). The beam current was limited to 3 µA as higher cur-rents 4–5 µA exhibited inconsistent dissolution and reprecipitation steps, resulting in an overall yield of 44 ± 21 % (n = 6). Dissolution time also played an important role in overall yield with at least one hour necessary to minimize losses in these first two steps. The separation procedure effectively removed all radiochemical contaminants and resulted in 72As(OH)3 isolated in a small volume, pH~4.5 water solution. Over the course of minutes to hours after back extraction, rapid auto-oxidation to 72AsO4H3 was observed. The bulk 72GeO2 target material, which was reclaimed from the isolation procedure, is being collected for future use. The synthesis of a targeted PET/MRI agent based on the functionalization of 72As-SPION has proved to be a difficult task. Experiments conjugating 72As-SPION to TRC105 through a PEG linker were unsuccessful, despite the investigation of a variety bioconjugation procedures. Current work is investigating the use of SPION@HMSN, which have a similar affinity for 72As as unencapsulated SPION. This new class of 72As-labeled SPION@HMSN has a hollow cavity for potential anti-cancer drug loading, as well as the mesoporous silica surface, which may facilitate the efficient conjugation of TRC105 using a well-developed bioconjugation technique. In summary, radioarsenic holds potential in the field of diagnostic and therapeutic nuclear medicine. However, this potential remains locked behind challenges related to its production and useful in vivo targeting. The present work strives to address several of these challenges through the use of enriched 72GeO2 target material, a chemical isolation procedure that reclaims the bulk of the target material, and the investigation of new targeted nanoparticle-based PET/MRI agents.
220

Metallic impurities in the Cu-fraction of Ni targets prepared from NiCl2 solutions

Manrique-Arias, J. C., Avila-Rodriguez, M. A. 19 May 2015 (has links) (PDF)
Introduction Copper-64 is an emerging radionuclide with applications in PET molecular imaging and/or internal therapy and it is typically produced by proton irradiation of isotopically enriched 64Ni electrodeposited on a suitable backing substrate. We recently reported a simple and efficient method for the preparation of nickel targets from electrolytic solutions of nickel chloride and boric acid [1]. Herein we report our recent research work on the analysis of metallic impurities in the copper-fraction of the radiochemical separation process. Material and Methods Nickel targets were prepared and processed as previously reported [1]. Briefly, the bath solution was composed of a mixture of natural NiCl2. 6H2O (135 mg/ml) and H3BO3 (15 mg/ml) and Ni was electrodeposited using a gold disk as cathode and a platinum wire as anode. The plating process was carried out at room temperature using 2 ml of bath solution (pH = 3.7) and a constant current density of 60 mA/cm2 for 1 hour. The unirradiated Ni targets were dissolved in 1–2 ml of concentrated (10M) HCl at 90 oC. After complete dissolution of the Ni layer, water was added to dilute the acid to 6M, and the solution was transferred onto a chromatographic column containing AG 1-X8 resin equilibrated with 6M HCl. The Ni , Co and Cu isotopes were separated by using the well-known chromatography of the chloro-complexes. The sample-fractions containing the Cu isotopes (15 ml, 0.1M HCl) were collected in plastic centrifuge tubes previously soaked in 1M HNO3 and rinsed with Milli-Q water (18 MΩ cm). Impurities of B, Co, Ni, Cu and Zn in these samples were determined by inductively coupled plasma-mass spectroscopy (ICP-MS) at the Department of Geosciences (Laboratory of Isotopic Studies) of the National University. Results and Conclusions The mass of Ni deposited in 1 h was 25.0 ± 1.0 mg (n = 3) and the current efficiency was > 75 % in all cases. The pH of the electrolytic solution tended to decrease along the electrodeposition process (3.71.6). The results of ICP-MS analysis of the Cu-fractions from the cold chromatography separation runs are shown in FIG. 1. We were particularly interested in the boron impurities as H3BO3 is used as buffer for electrodeposition of the Ni targets. Except for the Ni impurities that were deter-mined to be in the range of ppm (mg/l), all other analyzed metallic impurities were found to be in the range of ppb (µg/l), including boron. The Co, Ni, Cu and Zn impurities determined in the Cu-fraction in this work using Ni targets electrode-posited from a NiCl2 acidic solution, are in the same order of magnitude compared with that obtained when using targets prepared from an alkaline solution [2], with the advantage of the simplicity of the electrodeposition method from NiCl2 solutions, as the target material is already recovered in the chemical form of NiCl2, enabling a simpler, one step process to prepare a new plating solution when using enriched 64Ni target material for the production of 64Cu.

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