Water–disaccharides interactions in saturated solution and the crystallisation conditions

This paper reports solubility data and measurements of viscosity of the saturated aqueous solutions of sucrose, maltitol, and trehalose. Likewise, the metastable zone width and velocity of nucleation of the three disaccharides are compared. The narrowest metastable zone is observed for maltitol and the largest for trehalose. Such behaviour is due to a higher affinity of trehalose for water. Moreover, the crystallisation of anhydrous disaccharides in aqueous solution necessitates that hydration water be removed and evacuated from crystal integration surface to the bulk of solution to allow the growth of crystals. This step of disassociation and diffusion of hydration water proves to be the controlling step of the crystallisation process. Structural features at the origin of the differences between the three sugars are studied by FTIR spectroscopy. Modifications of frequencies and intensities of the vibrations around the glycosidic bond are interpreted in terms of conformational flexibility. Arguments like H-bond strength or conformational flexibility of the two monomers around the glycosidic oxygen were evoked as possible explanations of the behaviour of disaccharides. Likewise stability of hydration of the disaccharides is derived from the interpretation of FTIR spectra. These structural features help in interpreting the differences in crystallisation conditions and to hypothesize about the cryoprotective ability of the studied molecules.     

Dynamic Mechanical Properties of Compatibilized PET with Radiation Oxidized HDPE

Summary Binary blends of HDPE/PET exhibit poor mechanical properties because of their non compatibility. In this work, HDPE was oxidized by gamma-ray preirradiation in air, subsequently heated to destroy peroxides formed by this irradiation and to form polar groups in the HDPE, and then extruded with PET as a compatibilizing method of the blend. The dynamic mechanical properties were studied, and an improvement was observed when the PET content was increased while the HDPE used was irradiated. The largest increase in the mechanical properties was observed for PET contents between 10 and 20% (w/w). The improvement in the dynamic mechanical properties is believed to occur because of a percolation effect of the PET in the HDPE matrix and the radiation-improved compatibility by means of polar groups formed in the polyethylene.     

Effect of Different Amounts of Graphite on the Sintering and Transverse Rupture Properties of Powder Metal Parts

Iron powders were mixed with graphite powders by 1-15 wt pct to produce block samples using powder metallurgy technique. The powders were blended in a three dimensional blender for 20 min and compacted in a die under 500 MPa by using a one directional press. Sinterability and mechanical properties of the samples with different carbon content were investigated. Sintering process was carried out on a belt furnace with flame curtain in dissociated ammonia atmosphere. Block samples produced were suitable for ASTM B-312 transverse rupture strength test apparatus and were tested with 0.050 kN/s velocity in a press under 100 g load. It was found that graphite amount up to 2 wt pct increased the contact area of particles and acted as a lubricant to affect the sintering behaviour positively. The results indicated that the samples containing up to 5 wt pct showed good sintering behaviour and also good hardness due to an increase in pearlite amount. However, the samples containing higher amount of graphite （more than 5 wt pct） affected the sintering behaviour negatively due to the settlement of free graphite around the Fe powders, which resulted in a decrease in the hardness and transverse rupture strength.     

Impact of Resonance Treatment on Minor Actinide Incineration in a D–T Thorium Fusion Concept

Resonance treatments have an essential role to reliable neutronic calculations with different neutronic parameters. In this study presents the effect of resonance treatment and various tritium breeder materials on the incineration of the nitride fuels containing minor actinide mixed thoria in the Deuterium–Tritium fusion driven hybrid reactor as time dependent. Neutron transport calculations under resonance treatment and without resonance treatment are performed by using XSDRNPM/SCALE 5 codes. The impact of resonance treatments and various tritium breeder materials on tritium breeding, energy multiplication, total fission rate (∑_f), cumulative fissile fuel enrichment, fissile fuel breeding, average burn up values are comparatively investigated. It is observed that the neutronic results affect from both resonance treatment and the tritium breeder materials as time dependent.     

Application of differential transform method on nonlinear integro-differential equations with proportional delay

In this work, we applied the differential transform method, by presenting and proving some theorems, to solve the nonlinear integro-differential equation with proportional delays. This technique provides a sequence of functions which converges to the exact solution of the problem. In order to show the power and the robustness of the method and to illustrate the pertinent features of related theorems, some examples are presented.     

Neutronic Analysis of the Laser Inertial Confinement Fusion–Fission Energy (LIFE) Engine Using Various Thorium Molten Salts

In this study, a neutronic performance of the Laser Inertial Confinement Fusion Fission Energy (LIFE) molten salt blanket is investigated. Neutronic calculations are performed by using XSDRNPM/SCALE5 codes in S₈–P₃ approximation. The thorium molten salt composition considered in this calculation is 75 % LiF—25 % ThF₄, 75 % LiF—24 % ThF₄—1 % ²³³UF₄, 75 % LiF—23 % ThF₄—2 % ²³³UF₄. Also, effects of the ⁶Li enrichment in molten salt are performed for all heavy metal salt. The radiation damage behaviors of SS-304 structural material with respect to higher fissionable fuel content and ⁶Li enrichment are computed. By higher fissionable fuel content in molten salt and with ⁶Li enrichment (20 and 50 %) in the coolant in form of 75 % LiF—23 % ThF₄—2 % ²³³UF₄, an initial TBR >1.05 can be realized. On the other hand, the 75 % LiF—25 % ThF₄ or 75 % LiF—24 % ThF₄—1 % ²³³UF₄ molten salt fuel as regards maintained tritium self-sufficiency is not suitable as regards improving neutronic performance of LIFE engine. A high quality fissile fuel with a rate of ~2,850 kg/year of ²³³U can be produced with 75 % LiF—23 % ThF₄—2 % ²³³UF₄. The energy multiplication factor is increased with high rate fission reactions of ²³³U occurring in the molten salt zone. Major damage mechanisms in SS-304 first wall stell have been computed as DPA = 48 and He = 132 appm per year with 75 % LiF—23 % ThF₄—2 % ²³³UF₄. This implies a replacement of the SS-304 first wall stell of every between 3 and 4 years.     

Monte Carlo calculations of the incineration of plutonium and minor actinides of laser fusion inertial confinement fusion fission energy(LIFE) engine

In this paper, neutronic analysis in a laser fusion inertial confinement fusion fission energy(LIFE) engine fuelled plutonium and minor actinides using a MCNP codes was investigated.LIFE engine fuel zone contained 10 vol% TRISO particles and 90 vol% natural lithium coolant mixture. TRISO fuel compositions have Mod(1): reactor grade plutonium(RG-Pu), Mod(2):weapon grade plutonium(WG-Pu) and Mod(3): minor actinides(MAs). Tritium breeding ratios(TBR) were computed as 1.52, 1.62 and 1.46 for Mod(1), Mod(2) and Mod(3), respectively. The operation period was computed as ～21 years when the reference TBR??1.05 for a selfsustained reactor for all investigated cases. Blanket energy multiplication values(M) were calculated as 4.18, 4.95 and 3.75 for Mod(1), Mod(2) and Mod(3), respectively. The burnup(BU)values were obtained as ～1230, ～1550 and ～1060 GWd tM~(-1), respectively. As a result, the higher BU were provided with using TRISO particles for all cases in LIFE engine.