Yousef Javadzadeh, Ameneh Mohammadi, Nazaninossadat Khoei and Ali Nokhodchi
A. A. Noyes and W. R. Whitney, The rate of solution of solid substances in their own solutions, J. Am. Chem. Soc. 19 (1987) 930--934.
A. Nokhodchi, N. Bolourtchian and R. Dinarvand, Dissolution and mechanical behaviors of recrystallized carbamazepine from alcohol solution in the presence of additives, J. Cryst. Growth 274 (2005) 573--584; DOI:10.1016/j.jcrysgro.2004.10.158.
Y. Kobayashi, Sh. Ito, Sh. Itai and K. Yamamoto, Physicochemical properties and bioavailability
Shock veins in the Sahara 02500 ordinary chondrite
A specimen of the Sahara 02500 ordinary chondrite contains shock-produced veins consisting of recrystallised fine-grained pyroxenes that include small droplets of Ni-rich metal. Non-melted olivines and pyroxenes show planar deformations filled by shock-melted and -polluted metal and troilite. Shock-melted feldspathic glass is present close to the shock veins. Geothermometric estimations indicate that the meteorite locally experienced moderate shock metamorphism with a minimum local peak temperature above 1400°C, resulting in partial melting of Ca-poor pyroxene and full melting of feldspars, metal and sulphides. The mineral assemblage in the shock veins suggests a pressure during melt recrystallisation below 10 GPa.
Ultrasonic welding is very useful for joining thin metal sheets [1, 2]. The effect of ultrasound on microstructure is currently not well understood because the changes produced depend very much on the welding parameters and the properties of the metal being considered. Thin sheets formed by cold rolling acquire a special grain structure. During the welding process the heat produced causes recrystallization; even where heat is not applied in the joining process the recrystallization process alters the mechanical properties within the heat affected zone (HAZ). The mechanical properties of the welded samples depend on the microstructure. In this work we analyse the ultrasonic welding effect on the joint and the HAZ [3, 4].
The preliminary results of 57Fe Mössbauer spectroscopy and X-ray diffraction (XRD) of fully metamict samarskite dated at ~1500 Ma, which absorbed α-dose of 6.5 × 1017 α-decay mg-1, are reported after one-hour annealing at 673, 873, 1173 and 1373 K in argon atmosphere. Metamict minerals contain radioactive elements that degrade their crystal structures over geological time. All the Mössbauer spectra obtained can be fitted to two quadrupole doublets assigned to Fe2+ and Fe3+ in octahedral positions. The relative contribution of Fe2+ (Fe2+/Fe) reaches a minimum of 0.10 at 1173 K.
Roman Farkašovský, Katarína Bónová and Marián Košuth
of the Helgeland Nappe Complex, Nord-Trøndelag, central Norway. Norges Geologiske Under Søkelse Bulletin 446, 35-41.
Rutter, E.H., 1999. On the relationship between the formation of shear zones and the form of the flow law for rocks undergoing dynamic recrystallization. Tectonophysics 303, 147-158.
Sassier, C., Boulvais, P., Gapais, D., Capdevila, R. & Diot, H., 2006. From granitoid to kyanite-bearing micaschist during fluid-assisted shearing (Ile d’Yeu, France). International Journal of Earth Science 95, 2
During our investigation lath martensite was produced in low carbon steels by austenitization at 1200 °C/20 min, and the cooling of samples in ice water. The samples were tempered at a range of temperatures. The tempering effects on microstructure and on mechanical proprieties were investigated. Some samples with lath martensite microstructure were cold rolled and heat treated at different temperatures. Recrystallization was observed after heat treatment at 600-700 °C.
This study aims to assess fatigue property by the static overload and average load in the fillet welded joints which is on the ship structural steel having gusset welds. To this end, a small specimen was made, to which the same welding condition for the actual ship structure was applied, to perform fatigue tests. In this study, a method to simply assess changes in welding residual stress according to different static overload was suggested. By measuring actual strain at the weld toe, the weld stress concentration factor and property which is determined by recrystallization in the process of welding were estimated to investigate the relation between overload and fatigue strength.
Șerban Andrei Gâz-Florea, Eleonora Mircia and Lavinia Berţa
Objective: Development of new electronic devices with applications in computer science as well as new medical devices pushed the researcher to find new technologies. Based on those new techniques we have designed and synthesized compounds with possible application in the field of advanced materials. Material and method: Compounds were analyzed by TLC and NMR. Routine 1H NMR (250 MHz) spectra were recorded at room temperature in deuterated acetone, unless stated otherwise. Thin-layer chromatography (TLC) was carried out on aluminum sheets coated with silicagel 60 F254 Merck TLC plates. Results: Starting from commercial available compounds intermediates were obtained in a good yield. 4,4′-(2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl)diphenol was obtained starting from pentaerythritol and p-hydroxy-benzaldehyde in the presence of catalytic amounts of APTS (p-toluensulfonic acid). The product was purified by recrystallization and characterized by NMR spectroscopy. The structure exhibit 2 different signals for equatorial and axial position. Furthermore di, tri and tetra ethylene glycol were obtained by microwave assisted synthesis in a matter of minutes. Compounds were separated by recrystallization. Conclusions: In conclusion, several intermediates were synthesized and characterized from spectroscopic point of view. Further analyses should be carried out and the compounds should be tested as advanced materials.
Bartholomew C. H. Mechanisms of catalyst deactivation, Applied Catalysis A:General, 2001, 212, 17.
Arabczyk W., Jasińska I. in Proceedeings of the 13th International Congress on Catalysis, Paris, 2004.
Jasińska I., Arabczyk W. Kinetic studies of the recrystallization process of iron catalyst for ammonia synthesis, Chem. Pap. , 2005, 59(6b), 496.
Arabczyk W. The state of studies on iron catalyst for the ammonia synthesis, Polish Journal of