79,102 research outputs found
Holographic analysis of thin films
Technique for monitoring deposition of films on surfaces, in place on a real-time basis, reads both the thickness and the uniformity of the deposited film. Holograms are produced from both reflected and transmitted light on one plate
Quick-change absorption column
Column has end caps held in place by springs; prefilled packs of absorbent can be exchanged quickly. Both ends of metal or plastic body tube of size which can hold adequate amount of absorbent are machined to provide seat for perforated plate and groove for its spring retainer ring
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Classification of information systems research revisited: A keyword analysis approach
A number of studies have previously been conducted on keyword analysis in order to provide a comprehensive scheme to classify information systems (IS) research. However, these studies appeared prior to 1994, and IS research has clearly developed substantially since then with the emergence of areas such as electronic commerce, electronic government, electronic health and numerous others. Furthermore, the majority of European IS outlets - such as the European Journal of Information Systems and Information Systems Journal - were founded in the early 1990s, and keywords from these journals were not included in any previous work. Given that a number of studies have raised the issue of differences in European and North American IS research topics and approaches, it is arguable that any such analysis must consider sources from both locations to provide a representative and balanced view of IS classification. Moreover, it has also been argued that there is a need for further work in order to create a comprehensive keyword classification scheme reflecting the current state of the art. Consequently, the aim of this paper is to present the results of a keyword analysis utilizing keywords appearing in major peer-reviewed IS publications after the year 1990 through to 2007. This aim is realized by means of the two following objectives: (1) collect all keywords appearing in 24 peer reviewed IS journals after 1990; and (2) identify keywords not included in the previous IS keyword classification scheme. This paper also describes further research required in order to place new keywords in appropriate IS research categories. The paper makes an incremental contribution toward a contemporary means of classifying IS research. This work is important and useful for researchers in understanding the area and evolution of the IS field and also has implications for improving information search and retrieval activities
Mercury accumulation in fishes from tropical aquatic ecosystems in the Niger Delta, Nigeria
Fishes are important biomarkers of trace elements in
aquatic ecosystems, and are used to evaluate the status
of water pollution by mercury in tropical aquatic ecosystems in Nigeria. Common fishes, Chrysichthys nigrodigitatus,Brycinus nurse, Hemichromis fasciatus,
Lutianus ava, Oreochromis nilotica, Pomadasys jubelini,
Stellifer stellifer and Tilapia guineensis were analysed
for Hg accumulation using the cold vapour atomic absorption spectrophotometry technique. The results
showed that Hg concentration in P. jubelini was relatively
the highest, with a mean concentration of 0.063 ± 0.03 mg kgâ1. Other concentration values were 0.044 ± 0.031 mg kgâ1 for O. nilotica, 0.026 ± 0.013 mg kgâ1 for B. nurse, 0.034 ± 0.034 mg kgâ1 for H. fasciatus, 0.023 ± 0.020 mg kgâ1 for C. nigrodigitatus and 0.33 ± 0.016 mg kgâ1 for L. ava. Concentrations of Hg accumulated by the fishes were low and within internationally accepted limit, not likely to cause mercury poisoning. Because of the high Hg accumulating potential of P. jubelini, it is recommended as a biomarker for assessment of Hg toxicity in a tropical aquatic environment
Light-Quark FLIC Fermion Simulations of the Exotic Meson
We investigate the mass of the exotic meson, created with hybrid
interpolating fields. Access to light quark masses approaching 25 MeV is
facilitated by the use of the Fat-Link Irrelevant Clover (FLIC) fermion action,
and large () lattices. Our results indicate that the
exotic exhibits significant curvature close to the chiral limit, and yield a
mass in agreement with the candidate and exclusive of
the .Comment: 6 pages, 1 table, 2 figures, talk given at Lattice '05. Removed
unccessary figure
Start-to-end modelling of a mode-locked optical klystron free electron laser amplifier
A free electron laser (FEL) in a mode-locked optical klystron (MLOK) configuration is modelled using start-to-end simulations that simulate realistic electron beam acceleration and transport before input into a full three-dimensional FEL simulation code. These simulations demonstrate that the MLOK scheme is compatible with the present generation of radiofrequency accelerator designs. A train of few-optical cycle pulses is predicted with peak powers similar to those of the equivalent conventional FEL amplifier. The role of electron beam energy modulation in these results is explained and the limitations of some simulation codes discussed. It is shown how seeding the FEL interaction using a High Harmonic seed laser can improve the coherence properties of the output
Hot Electron Capture Dissociation Distinguishes Leucine from Isoleucine in a Novel Hemoglobin Variant, Hb Askew, ÎČ54(D5)ValâIle
Population migration has led to the global dispersion of human hemoglobinopathies and has precipitated a need for their identification. An effective mass spectrometry-based procedure involves analysis of the intact α- and ÎČ-globin chains to determine their mass, followed by location of the variant amino acid residue by direct analysis of the enzymatically digested chains and low-energy collision induced dissociation of the variant peptide. Using this procedure, a variant was identified as either ÎČ54ValâLeu or ÎČ54ValâIle, since the amino acids leucine and isoleucine cannot be distinguished using low-energy collisions. Here, we describe how hot electron capture dissociation on a Fourier transform-ion cyclotron resonance mass spectrometer was used to distinguish isoleucine from leucine and identify the mutation as ÎČ54(D5)ValâIle. This is a novel variant, and we have named it Hb Askew
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