[en] In this report, we will first briefly describe the phenomena, underlying mechanisms and necessary criteria of DDT, then summarize the experimental work on hydrogen explosion performed at the SWL of RWTH Aachen. Then we will explain the CFD codes SHOCKIN and AIXCO as well as the applications in the simulation of DDT processes. Studies performed at the SWL include three topics: 1) self-ignition phenomena; 2) DDT mechanisms in axis-symmetric geometry with periodic obstacles or a single obstacle; and 3) detonation formation at the entrance to narrow gaps. A database of ignition delay times and schlieren records has been set up for hydrogen-air-steam/CO₂ mixtures. Excellent photographs concerning shock reflections and ignition were produced providing good materials for the validation of computer codes. (orig.)

[en] Absorbing dust particles in an isotropic radiation field shadow each other by a solid angle which is inversely proportional to the square of the distance between the two particles, leading to an inverse-square attractive force - mock gravity. The effect is largest in an optically thin medium. Recently Hogan and White (HW, hereafter) proposed that if the pre-galactic universe contained suitable sources of radiation and dust, instability in the dust distribution caused by mock gravity may have led to the formation of galaxies and galaxy clusters. In their picture of a well-coupled dust-gas medium, HW show that mock gravity begins to dominate gravitational instability when the perturbation becomes optically thin, provided that the radiation field at the time is strong enough. The recent rocket observation of the microwave background at submillimeter wavelengths by Matsumoto et al. might be from pre-galactic stars, the consequence of the absorption of ultraviolet radiation by dust, and infrared reemission which is subsequently redshifted. HW's analysis omits radiative drag, incomplete collisional coupling of gas and dust, finite dust albedo, and finite matter pressure. These effects could be important. In a preliminary calculation including them, the authors have confirmed that mock gravitational instability is effective if there is a strong ultraviolet radiation at the time, but any galaxies that form would be substantially enriched in heavy elements because the contraction of the dust is more rapid than that of the gas. Moreover, since the dust moves with supersonic velocity through the gas soon after the perturbation becomes optically thin, the sputtering of dust particles by gas is significant, so the dust could disappear before the instability develops significantly

[en] To analysis the behavior of the mechanical properties of concrete-filled double skin steel tubular (CFDST) columns under eccentric loads after fire, the finite element analysis was used. The established FEA modeling was verified by the experimental results which has a good agreement. The FEA modeling was then used to perform the temperature field and the full-range load-deformation relations of the CFDST subject to eccentric compression after exposed to fire. The results indicate that: with the time of fire increasing, the eccentric distance increasing, the steel ratio decreasing, the yield strength decreasing and compressive strength decreasing, the bearing capacity of CFDST in circle section under eccentric loads is showing a decrease trend, and the stiffness of component decreases with the time of fire increasing, the eccentric distance increasing and the steel ratio decreasing. The ductility of CFDST became better with the time of fire increasing and the eccentric distance increasing. (Author)

[en] Calmodulins, members of the EF-hand family of Ca/sup 2+/ binding proteins, play significant regulatory roles in the processes of plant cell proliferation, growth, development, photosynthesis and stress resistance. Here, the two full-length complementary DNA (cDNA) clones were isolated from the constructed Camellia oleifera cDNA library. They are 953 base pair (bp) and 1024 bp in the length, respectively, and designated as CoCaM1 and CoCaM2 (GenBank access numbers EU856536 and FJ649316). They contain the complete protein-coding region of 447 bp encoded an identical polypeptide of 149 amino acids and various lengths of untranslated segments. The result supported the hypothesis 'Multigenes possess an identical amino acid sequence'. The structure analyzed results indicated the putative CoCaM protein possessed four EF-hand domains, hydrophobic residues and crucial residues, in which the amphipathic helices might possess lipid affinity via binding and altering the associated plasma or organelle membranes. In addition, the protein had one to seven substitutions, and displayed more than 89% identity at the amino acid level in comparison to other species CaMs. Finally, the expression of the 2 cDNA genes in matured seeds of 6 C. oleifera varieties was analyzed by real-time fluorescence quantitative PCR, and the result showed that there were different expression levels. In conclusion, the structure properties together with the observed expression levels indicate that they may play different roles in the processes of development, lipid biosynthesis and stress responses of C. oleifera seeds. (author)

[en] Skimmed milk powders (SMP) were produced by ultrasonic atomizing-assisted spray drying (UASD). It was found that UASD can produce high quality SMP (with < 5% moisture content and < 2% insolubility) at lower inlet temperatures (~130°C). The particle size of the UASD-SMP was 10 times smaller (decreased from ~20 μm to 4 μm) than the tranditionally spray-dried SMP and the color appeal of UASD-SMP was also better (L* value increased by > 6 %). Overall, this research shown that UASD can be used to produce small particle size and high quality SMP. (Author)

[en] This work is concerned with NiCrAlY and NiCoCrAlY coatings deposited on the superalloy IC-6 (Ni₃Al-base superalloy) by arc ion plating (AIP). The results indicated that the presence of Al and Mo in alloy IC-6 impeded Cr atoms moving from coatings to substrates during the deposition process. As a consequence, the distribution of Cr is well proportioned in both NiCrAlY and NiCoCrAlY coatings. Vacuum heat treatment drastically increased diffusivities and the coating became more uniform. The interdiffusion also led to the phase transformation in the coatings. Although γ'-Ni₃Al and γ-Ni were still the major phases in the coating, their lattice constant a₀ decreased. The results of isothermal oxidation showed that the oxidation behavior of coatings obeyed the parabolic rate law. The oxidation resistance was not influenced very much by the presence of Co in the NiCrAlY coating at 900 deg. C static atmosphere. NiCoCrAlY coating had poorer oxidation resistance than NiCrAlY coating when they were exposed at 1000 deg. C

[en] Graphical abstract: (a) As-deposited nano-crystalline Ni (b) large grain growth at simultaneous low temperature (0.2T_m) and low stress (0.2σ_Y) loading compared to the literature predicting grain growth around 0.4T_m and/or σ_Y loading conditions. -- The influence of temperature and stress on grain growth was investigated in nanocrystalline nickel thin films in situ inside a transmission electron microscope. Independently, temperature and stress did not show any appreciable effect. However, concurrent loading at only 20% of melting temperature and 20% of yield stress resulted in significant grain boundary mobility and grain growth. We propose that grain growth in nanocrystals is a stress-heterogeneity-relieving mechanism that may not necessarily be associated with plasticity as proposed in the literature

[en] In our continuing search for more potent anticancer agent, eight novel nitrates couple with C-10 colchicine nitric oxide-releasing derivatives (5a-f and 7a-b) were prepared. These target compounds were assayed for their anti-tumor activity in vitro against four cancer cell lines, including human hepatocellular carcinoma cells (BEL7402), human ovary carcinoma cells (A2780), human lung adenocarcinoma cells (A549) and human breast carcinoma cells (MCF7). Preliminary results indicated that most of them exhibited significant cytotoxic effect toward cancer cells. Compound 7a was investigated further for its more potent cytotoxicity than colchicine. (author)

[en] A parallel algorithm has been designed for SHELXD to solve the heavy-atom partial structures of protein crystals quickly. Based on this algorithm, a program has been developed to run on high-performance multiple-CPU Linux PCs, workstations or clusters. Tests on the 32-CPU Linux cluster at SER-CAT, APS, Argonne National Laboratory, show that the parallelization dramatically speeds up the process by a factor of roughly the number of CPUs applied, leading to reliable and instant heavy-atom sites solution, which provides the practical opportunity to employ heavy-atom search as an alternative tool for anomalous scattering data quality evaluation during single/multiple-wavelength anomalous diffraction (SAD/MAD) data collection at synchrotron beamlines

No abstract available