226Th (T1/2=31min) is a promising therapeutic radionuclide since results, published in 2009, showed that it induces leukemia cells death and activates apoptosis pathways with higher efficiencies than ...213Bi. 226Th can be obtained via the 230U α decay. This study focuses on the 230U production using the 232Th(d,4n)230Pa(β−)230U reaction.
Experimental cross sections for deuteron-induced reactions on 232Th were measured from 30 down to 19MeV using the stacked-foil technique with beams provided by the ARRONAX cyclotron. After irradiation, all foils (targets as well as monitors) were measured using a high-purity germanium detector.
Our new 230Pa cross-section values, as well as those of 232Pa and 233Pa contaminants created during the irradiation, were compared with previous measurements and with results given by the TALYS code. Experimentally, same trends were observed with slight differences in orders of magnitude mainly due to the nuclear data change. Improvements are ongoing about the TALYS code to better reproduce the data for deuteron-induced reactions on 232Th.
Using our cross-section data points from the 232Th(d,4n)230Pa reaction, we have calculated the thick-target yield of 230U, in Bq/μA·h. This value allows now to a full comparison between the different production routes, showing that the proton routes must be preferred.
Experimental cross sections for deuteron induced nuclear reactions on natural titanium were measured, using the stacked-foil technique and gamma spectrometry, up to 34 MeV with beams provided by the ...ARRONAX cyclotron. The experimental cross section values were monitored using the (nat)Ti(d,x)(48)V reaction, recommended by the IAEA. The excitation functions for (nat)Ti(d,x)(44m,46,47,48)Sc are presented and compared with the existing ones and with the TALYS 1.6 code calculations using default models. Our experimental values are in good agreement with data found in the literature. TALYS 1.6 is not able to give a good estimation of the production cross sections investigated in this work. These production cross sections of scandium isotopes fit with the new Coordinated Research Project (CRP) launched by the International Atomic Energy Agency (IAEA) to expand the database of monitor reactions.
Fully bio-based and biodegradable all-cellulose composites were prepared in the form of films by partial dissolution of two cellulose sources: a commercially available microfibrillated cellulose ...(MFC) and filter paper (FP). The solvent selected for this work was the ionic liquid 1-butyl-3-methylimidazolium chloride (C
4mimCl). Both cellulose sources were partially dissolved at 80
°C and consolidated by partial dissolution, resulting in excellent mechanical properties. X-ray diffraction and electron microscopy demonstrated that partial dissolution was a viable path to transform FP into a continuous paracrystalline matrix reinforced with cellulose I crystallites. In contrast, partially dissolved MFC was not as thoroughly dissolved and large amounts of undissolved material were still visible along the centre line of the films after the longest dissolution times. Consequently, partially dissolved MFC retained its initially high crystallinity. The degree of polymerization of the materials after dissolution was significantly reduced.
Novel all-cellulose composite films were prepared by partly dissolving microcrystalline cellulose (MCC) powder in an 8% LiCl/DMAc solution. Cellulose solutions were precipitated and the resulting ...gels dried in a vacuum bag to produce films approximately 0.2–0.3
mm thick. X-ray diffraction (XRD) was used to characterise lateral crystal size and transmission electron microscopy (TEM) was employed to assess the morphology of the composites. During dissolution, the fibrous fragments of MCC were split into thinner cellulose fibrils and crystals were progressively broken down into thinner crystals. The composites were tested in tension and fracture surfaces were inspected by scanning electron microscopy (SEM). It was found that the mechanical properties and final morphology of all-cellulose composites was controlled by the rate of precipitation, initial cellulose concentration and dissolution time. The precipitation conditions were found to play a large role in the optimisation of the mechanical properties by limiting the amount of defects that were induced by differential shrinkage. All-cellulose composites were produced with a tensile strength up to 106
MPa and a tensile modulus up to 7.6 GPa.
Summary
All‐cellulose composites were prepared across a range of different crystallinities in order to examine relationships between phase composition and viscoelastic behaviour in the temperature ...range of 270 °C to 340 °C corresponding to the α1 mechanical relaxation. Composite films were prepared by partial dissolution of microcrystalline cellulose in a LiCl/N,N‐dimethylacetamide (LiCl/DMAc) solvent system using the film casting technique. Dynamic mechanical analysis showed two contributions to α1 relaxation, with tan δ maxima at 303 ± 2 °C and at approximately 325 °C. The height of the maximum or shoulder at 303 ± 2 °C decreased with increasing crystallinity, and was therefore assigned to molecular motion associated with chemical decomposition in non‐crystalline domains. The maximum at 325 °C was assigned to chemical decomposition in chains associated with the surfaces of crystalline domains. Composites with high crystallinity showed best retention of the dynamic storage modulus when tested at 300 °C.
All-cellulose composites are high performing green materials and solvent infusion processing makes their upscaled manufacturing possible. This study explored the use of aqueous 7wt.% NaOH/12wt.% urea ...solution as cost effective and environmentally friendly cellulose solvent for solvent infusion processing. A short dissolution time of 5min led to all-cellulose composite laminates with a tensile strength of 114±1.9MPa and a Young’s modulus of 7.8±0.5GPa. A decrease of tensile strength and Young’s modulus with increasing dissolution time from 5 to 60min was linked to changes in composite microstructure and fine structure of the reinforcing rayon fibres. It was shown that aqueous NaOH/urea solution is a promising alternative solvent, as it offers the advantages of shorter processing times and reduced solvent costs by 97%, while resulting in 25% stronger laminates, when compared to using ionic liquids.
186gRe is a β-/γ emitter of great interest for nuclear medicine. It has shown successful results on bone metastases palliation and has similar chemical properties as 99mTc, the most commonly used ...imaging agent. 186gRe is routinely produced using rhenium target in nuclear reactor. Higher specific activity could be obtained using accelerators. In this paper, production cross section values are presented for the natW(d,x)186gRe reaction up to 34MeV, using the stacked-foils method and gamma spectrometry. From this data set, the thick target production yield of 186gRe is determined and compared with the validated values of the IAEA and also with the proton route. The production cross sections of the natW(d,x)183,182g,184m,184g,181Re and natW(d,x)187W reactions have also been determined. A good agreement is found with the literature. Our data are compared with the version 1.6 (December 2013) of the TALYS code which shows discrepancies both on the shape and on the amplitude for these deuteron induced reactions.
•Deuteron induced reactions on natural tungsten up to 34MeV.•Experimental values were determined using the stacked-foil technique.•Comparison with the TALYS code version 1.6.•Thick target yield of 186gRe, 183,182g,184m,184g,181Re and 187W.
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