CCVD synthesis of carbon nanotubes from (Mg,Co,Mo)O catalysts: influence of the proportions of cobalt and molybdenum

Carbon nanotubes have been synthesised by catalytic chemical vapour deposition of a H2–CH4 mixture (18 mol% CH4) over (Mg,Co,Mo)O catalysts. The total amount of cobalt and molybdenum has been kept constant at 1 cat% and the proportion of molybdenum with respect to cobalt has been varied from x(Mo) = 0.25–1.0. This variation has important effects on both the yield and the nature (number of walls, straight walls or bamboo-like structures) of the carbon nanotubes. It also has an influence on the purity of the samples (amount of encapsulated metal particles, presence or not of amorphous carbon deposits). For x = 0.25, the nanotubes were mainly double- and triple-walled (inner diameter less than 3 nm); samples prepared from catalysts with higher molybdenum ratios contained larger multi-walled carbon nanotubes (inner diameter up to 9 nm), having up to 13 concentric walls. It is proposed that different growth mechanisms may occur depending on the initial composition of the catalyst

Network of Recurrent events - A case study of Japan

A recently proposed method of constructing seismic networks from 'record breaking events' from the earthquake catalog of California (Phy. Rev. E, 77 6,066104, 2008) was successfull in establishing causal features to seismicity and arrive at estimates for rupture length and its scaling with magnitude. The results of our implementation of this procedure on the earthquake catalog of Japan establishes the robustness of the procedure. Additionally, we find that the temporal distributions are able to detect heterogeneties in the seismicity of the region.Comment: 13 pages, 6 figures, 1 tabl

The discourses of doing science in English

In January 2003, Malaysia re-adopted the English language as a medium of instruction for science and mathematics. This change in the medium of instruction brings with it challenges of its own. What does it mean to 'do' science in the Malaysian context and to do so in English? How does the change in the medium of instruction from Bahasa Malaysia to English impinge upon current instructional and literacy practicesof teachers and learners? What kinds of change are required of the community that is invested in the teaching of science? This paper will address these questions by troubling some common-sense assumptions of 'doing' science in the Malaysian context in the light of findings of a qualitative case study conducted to investigate how one two teachers working in different contexts in a Malaysian school copes with the new medium of instruction and the myriad of issues that come with it

Writing a Life Between Gender Lines Conversations with A. Revathi about her autobiography The Truth About Me: A Hijra Life Story

A. Revathi was born physiologically male but felt and behaved like a girl - this is how she tells her story, as will be clear from the interview below. Nearly her whole childhood, spent in a village in Salem district of Tamil Nadu, was plagued by this deep and nagging unease of being trapped in the wrong body and by 'a growing sense of irrepressible femaleness'. But when she behaved like one of her girl-playmates, it only meant repeated humiliation and violence by her family and community. This affected her academic performance, and she had to drop out of school after failing the tenth grade. In a quest to be true to herself, Revathi, still in her teens, ran away from home and travelled to Delhi to join a house of hijras. Hijras are male-to-female transsexuals who undergo a surgical removal of the genitals (often performed surreptitiously and in unsanitary conditions) and comprise a distinct community across India with elaborate customs and regulations of their own. Hijras are given ritualistic importance by mainstream Indian society (for instance, their blessings are considered to bring good fortune) but at the same time they are easy targets for sexual crimes, discriminated against in public spaces, and have few options for livelihood apart from performing at social events, begging or prostitution. Revathi, now in her mid-forties, discusses all this with remarkable candour and courage in her autobiography The Truth About Me: A Hijra Life Story, translated into English from Tamil by V. Geetha and published by Penguin India Books in 2010. This autobiography is among the very first of its kind in India, uninhibited with regard to divisive gender lines, sexual hypocrisy of 'traditional' societies, and the dismal lack of public discourse on the rights of sexual minorities

Interplanetary Consequences of a Large CME

We analyze a coronal mass ejection (CME) which resulted from an intense flare in active region AR486 on November 4, 2003. The CME propagation and speed are studied with interplanetary scintillation images, near-Earth space mission data, and Ulysses measurements. Together, these diverse diagnostics suggest that the internal magnetic energy of the CME determines its interplanetary consequences.Comment: 5 pages, 9 figures, To appear in "Magnetic Coupling between the Interior and the Atmosphere of the Sun", eds. S.S. Hasan and R.J. Rutten, Astrophysics and Space Science Proceedings, Springer-Verlag, Heidelberg, Berlin, 200

Oscillation Criteria of Second-Order Quasi-Linear Neutral Delay Difference Equations

2000 Mathematics Subject Classification: 39A10.The oscillatory and nonoscillatory behaviour of solutions of the second order quasi linear neutral delay difference equation Δ(an | Δ(xn+pnxn-τ)|α-1 Δ(xn+pnxn-τ) + qnf(xn-σ)g(Δxn) = 0 where n ∈ N(n0), α > 0, τ, σ are fixed non negative integers, {an}, {pn}, {qn} are real sequences and f and g real valued continuous functions are studied. Our results generalize and improve some known results of neutral delay difference equations

Low prevalence of methicillin resistant as determined by an automated identification system in two private hospitals in Nairobi, Kenya: a cross sectional study

Background: Staphylococcus aureus (S.aureus) is a major cause of both healthcare and community acquired infections. In developing countries, manual phenotypic tests are the mainstay for the identification of staphylococci with the tube and slide coagulase tests being relied upon as confirmatory tests for S. aureus. The subjectivity associated with interpretation of these tests may result in misidentification of coagulase negative staphylococci as S.aureus. Given that antibiotic resistance is more prevalent in CONS, this may result in over estimation of methicillin resistant S.aureus (MRSA) prevalence. Methods: A review of susceptibility data from all non-duplicate S.aureus isolates generated between March 2011 and May 2013 by the Vitek-2 (bioMérieux) automated system was performed by the authors. The data was generated routinely from processed clinical specimens submitted to the microbiology laboratories for culture and sensitivity at the Aga Khan University Hospital and Gertrude’s children’s hospital both situated in Nairobi. Results: Antimicrobial susceptibility data from a total of 731 non-duplicate S.aureus isolates was reviewed. Majority (79.2%) of the isolates were from pus swabs. Only 24 isolates were both cefoxitin and oxacillin resistant while 3 were resistant to oxacillin but susceptible to cefoxitin giving an overall MRSA prevalence of 3.7% (27/731). None of the isolates were resistant to mupirocin, linezolid, tigecycline, teicoplanin or vancomycin. Conclusion: The prevalence of MRSA in this study is much lower than what has been reported in most African countries. The significant change in antibiotic susceptibility compared to what has previously been reported in our hospital is most likely a consequence of the transition to an automated platform rather than a trend towards lower resistance rates

Effect of immunostimulant on enhancement of the immune response of kuruma shrimp Marsupenaeus japonicus and its resistance against White Spot Syndrome Virus (WSSV)

An experiment of 45 days duration to test the efficacy of the Vibrio alginolyticus as an immunostimulant was conducted in Marsupenaeus japonicus against white spot syndrome virus (WSSV) infection, considered as one of the serious pathogens of shrimps. The shrimps were fed with the experimental diets coated with different concentrations of bacteria of 17 ml / kg feed and 10 % of animal body wt. They were challenged with WSSV to assess the increase in survival rate and growth if any due to immune enhancement. Another group of shrimp was used for drawing the haemolymph to estimate the increase in the level of prophenoloxidase activity. Samplings for the above said analysis were carried out at 15 days interval for a period of 45 days. The highest prophenoloxidase activity (39.78 with sand substrate-T1) and the highest survival rate (66.66 % with sand substrate-T1) and highest growth rate (7.04 % in 17ml/kg- with sand substrate-T1) were recorded in experimental diet (17 ml / kg feed). Hence the 17 ml / kg feed of Vibrio alginolyticus formalin killed added to the diet could be an eco-friendly and economically viable immunostimulant for penaeid shrimps