The effect of jet preheating on turbulence in a premixed jet in hot coflow

Moderate or Intense Low oxygen Dilution (MILD) combustion is an important combustion regime, which utilises the combustion of gas in hot and often vitiated environment. MILD combustors are characterised by the use of exhaust gases recirculated into the combustor via dilution or mixing with the incoming fuel or alternately by rapidly mixing an incoming fuel stream into a hot environment of combustion products. However, the influence of preheating the fuel jet is not well understood. Current approaches rely heavily on assumptions about the role of heat on laminarisation of turbulence, due to viscosity. However, the density ratio between jet and environment is known to have a dominant effect on mixing. Velocity measurements are presented for a pair of turbulent premixed flames issuing into a premixed coflow. Two cases are considered, both with and without preheating of the central fuel jet. The resulting near-field velocity is measured using digital Particle Image Velocimetry (PIV). The resulting velocity maps are processed to find the turbulence intensity, u’/U. A two-point correlation technique is used to determine the turbulence integral length scale, lf. The influence of preheating the central jet on the resulting near-field turbulence characteristics are presented and discussed.P.A.M. Kalt and B.B. Dallyhttp://cfe.uwa.edu.au/news/acs2013http://www.anz-combustioninstitute.org

Acute oral toxicity and phytochemical study of "Diabenorme" and "Thuquinone" used to treat diabetes

The aim of the study was conducted to search for phytochemicals and evaluate the acute oral toxicity in mice for aqueous extracts of "Diabenorme" and "Thuquinone" used in the treatment of diabetes. "Diabenorme" is a combination of two medicinal plants: Persea americana (Lauraceae) and Anacardium occidentale (Anacardiaceae) while "Thuquinone" is composed of Pycnanthus angolensis (Myristicaceae). Phytochemical analysis was done using standard methods and acute toxicity test (OCDE 423) was performed by a fixed dose procedure consist in administration of three doses of 300, 2000 and 5000 mg/kg body weight of "Diabenorme" and "Thuquinone". Phytochemical analysis showed that the different drugs contained polyphenols, flavonoids, catechin tannins, alkaloids and saponins. Concerning acute toxicity test, no sign of toxicity and mortality were observed during the experiment after limit test of 5000 mg/kg. Thus, there were no significant differences (Fischer test, P ˃ 0.05) in the body weights between the control and treated animals. These results show that the aqueous extracts of "Diabenorme" and "Thuquinone" are potentially safe for oral consumption at acute administration up to dose of 5000 mg/kg. Further investigation is needed to evaluate its sub-acute toxicity.Keywords: Diabenorme, Thuquinone, Phytochemical screening, acute toxicity

Assessment of neuroprotective potential of Tualang honey in alzheimer model of rat

Reduction in cerebral blood flow (CBF) due to aging has been associated with neurodegenerative disorders including Alzheimer’s disease and dementia. Experimentally, a condition of chronic cerebral hypoperfusion due to reduced CBF can be induced by permanent bilateral occlusion of common carotid arteries (2-vessel occlusion, 2VO) in rats. Honey is a natural product that has been widely used since long time as a nutrient, for its therapeutic effects in traditional medicine, and recently as an antioxidant. Since oxidative stress leading to neuroinflammation, resulting in neuronal apoptosis and death, is one of the mechanisms which is thought to play a significant role in chronic degenerative neurological disorders, the present study was planned to assess the neuroprotective role of Honey in chronic cerebral hypoperfusion-induced neurodegeneration. After acclimatization, thirty Sprague Dawley rats weighing 200-250 g were equally divided into three groups. Group A – sham control, Group B – 2VO, and Group C – 2VO-H (treated daily with Honey (1.2 g/kg freshly diluted with distilled water, orally by 30 gavage every morning following 2VO). At 10th week, all the rats were euthanized and the hippocampi were isolated. Viable neuronal cell were count in the hippocampal CA-1 region. The results showed damaged, distorted, irregular cells with shrunken cytoplasm and dark pykonotic nuclei in 2VO rats as compared to sham control (p<0.001). Treatment of rats with honey restored the hippocampal cells to their normal structure and revealed the reduced loss of neurons in 2VO+H rats as compared to untreated 2VO rats (p<0.001). This study shows that Malaysian tualang honey might have therapeutic potential for the treatment of chronic cerebral hypoperfusion related neurodegenerative disorders including Alzheimer’s disease

Effects of Symmetry Breaking on the Strong and Electroweak Interactions of the Vector Nonet

Starting from a chiral invariant and quark line rule conserving Lagrangian of pseudoscalar and vector nonets we introduce first and second order symmetry breaking as well as quark line rule violating terms and fit the parameters, at tree level, to many strong and electroweak processes. A number of predictions are made. The electroweak interactions are included in a manifestly gauge invariant manner. The resulting symmetry breaking pattern is discussed in detail. Specifically, for the ``strong'' interactions, we study all the vector meson masses and V -> \phi \phi decays, including isotopic spin violations. In the electroweak sector we study the { rho^0 , omega , phi } -> e^+e^- decays, { pi^+ , K^+ , K^0 } ``charge radii'', K_{l3} ``slope factor'' and the overall e^+e^- -> pi^+ pi^- process. It is hoped that the resulting model may be useful as a reasonable description of low energy physics in the range up to about 1 GeV.Comment: 43 pages (LaTeX), 5 PostScript figures are included as uuencoded-compressed-tar file at the en

The influence of coal particle and air jet momenta on MILD combustion in a recuperative furnace

The moderate or intense low-oxygen dilution (MILD) combustion regime is a promising technology that operates at high combustion efficiency and lessens pollutant emissions. This numerical study of a parallel jet recuperative MILD combustion furnace investigates the effects of coal particle size and inlet air momentum on furnace dynamics and global CO emissions. It is found that coal particle size affects the coal penetration depth within the furnace and the location of a particle stagnation point. The effects of air inlet momentum are tested in two ways, first by raising the inlet temperature at constant mass flow rate, and second by increasing the mass flow rate at constant temperature. In both cases, increasing the air jet momentum broadens the reaction zone and facilitates MILD combustion, but also increases CO emissions due to lowered reaction rates.Emmet M. Cleary, Paul R. Medwell, Bassam B. Dallyhttp://cfe.uwa.edu.au/news/acs2013http://www.anz-combustioninstitute.org

Pion and Kaon Vector Form Factors

We develop a unitarity approach to consider the final state interaction corrections to the tree level graphs calculated from Chiral Perturbation Theory ($\chi PT$) allowing the inclusion of explicit resonance fields. The method is discussed considering the coupled channel pion and kaon vector form factors. These form factors are then matched with the one loop $\chi PT$ results. A very good description of experimental data is accomplished for the vector form factors and for the $\pi\pi$ P-wave phase shifts up to $\sqrt{s}\lesssim 1.2$ GeV, beyond which multiparticle states play a non negligible role. In particular the low and resonance energy regions are discussed in detail and for the former a comparison with one and two loop $\chi PT$ is made showing a remarkable coincidence with the two loop $\chi PT$ results.Comment: 20 pages, 7 figs, to appear in Phys. Rev.

'I make up a silly name': Understanding Children's Perception of Privacy Risks Online

Children under 11 are often regarded as too young to comprehend the implications of online privacy. Perhaps as a result, little research has focused on younger kids' risk recognition and coping. Such knowledge is, however, critical for designing efficient safeguarding mechanisms for this age group. Through 12 focus group studies with 29 children aged 6-10 from UK schools, we examined how children described privacy risks related to their use of tablet computers and what information was used by them to identify threats. We found that children could identify and articulate certain privacy risks well, such as information oversharing or revealing real identities online; however, they had less awareness with respect to other risks, such as online tracking or game promotions. Our findings offer promising directions for supporting children's awareness of cyber risks and the ability to protect themselves online

The M-Machine Multicomputer

The M-Machine is an experimental multicomputer being developed to test architectural concepts motivated by the constraints of modern semiconductor technology and the demands of programming systems. The M- Machine computing nodes are connected with a 3-D mesh network; each node is a multithreaded processor incorporating 12 function units, on-chip cache, and local memory. The multiple function units are used to exploit both instruction-level and thread-level parallelism. A user accessible message passing system yields fast communication and synchronization between nodes. Rapid access to remote memory is provided transparently to the user with a combination of hardware and software mechanisms. This paper presents the architecture of the M-Machine and describes how its mechanisms maximize both single thread performance and overall system throughput