Showing papers by "Applied Science Private University published in 1996"

Evidence of Nonlocal Breakdown of the Integer Quantum Hall Effect

Abstract: Current induced breakdown of the integer quantum Hall effect (QHE) is studied in GaAs $/$AlGaAs single heterostructure Hall bars at $T\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.6$--4.2 K and $B\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}2$--6 T ( $\ensuremath{ u}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}2$, 4, and 6). The QHE breakdown is absent over a macroscopic region in the two-dimensional electron gas channel on the side of the electron-injecting corner of the Hall bars. The observed nonlocal nature suggests that bootstrap-type electron heating is relevant to the QHE breakdown.

Statistical process monitoring with principal components

Abstract: Most industrial processes are characterized by a system of several variables, all of which are subject to drifts, disturbances, and assignable causes of variation. In the chemical and process industries, there are often inertial forces arising from raw material streams, reactors and tanks that introduce serial correlation over time into these variables. This autocorrelation can have a profound impact on the effectiveness of the statistical monitoring methods used for such processes. This paper reviews some of the available methodology for multivariate process monitoring and shows the effectiveness of principal components in this context. An application of the principal components approach with correlated observation vectors is presented. The effectiveness of this procedure to indicate process upsets is discussed.

Keystroke Dynamics Based Authentication

Abstract: This chapter deals with the applications of keystroke dynamics to authenticate/verify access to computer systems and networks. It presents our novel contribution to this area along with other related works. The use of computer systems and networks has spread at a rate completely unexpected a decade ago. Computer systems and network are being used in almost every aspect of our daily life. As a result, the security threats to computers and networks have also increased significantly. We give a background information including the goals of any security system for computers and networks, followed by types of security attacks on computers and networks. We present the applications of keystroke dynamics using interkey times and hold times as features to authenticate access to computer systems and networks.

Molecular Genetic (RAPD) Analysis of Breeding Magpie Geese

Abstract: -Magpie Geese (Anseranus semipalmata) typically form nesting trios consisting of two females and one male, an uncommon breeding arrangement for waterfowl. To study aspects of their reproductive biology, 20 reproductively active adults representing seven reproductive groupings (broods) were scored for 106 polymorphic primer-specific RAPD bands. Genetic distances between all possible adult pairs were calculated, and these values were analyzed using the Mantel test. In the pairwise comparison of genetic distances, those between males were significantly less than those for other adult combinations (P < 0.05). Using the same analytical approach, we found that females that shared a nest were more like one another than were females that did not share a nest (P < 0.05). We suggest that a plausible hypothesis to account for the relative genetic homogeneity of the male population is that males seeking to enter the breeding population do so at their natal site. The females they recruit are more closely related to one another than are females in general. Received 5 April 1995, accepted 29 June 1995. LARGE NUMBERS of Magpie Geese (Anseranus semipalmata) congregate at seasonal wetlands in tropical northern Australia. The bird's unique morphology (including partially webbed, heavily clawed feet with an opposable fourth toe) led to its taxonomic placement in its own family. This uniqueness also is evident at the molecular level, and recent taxonomies derived from mitochondrial DNA sequences support the view that this species should be assigned to a family of its own (Sraml et al. 1996). Although abundant in parts of northern Australia, the current distribution of the Magpie Goose is only a remnant of its former range, which has been severely restricted over the past 200 years by the introduction of European-style agricultural practices. Situations that threaten this species could arise again as the result of conflicts between the bird's habitat requirements and changing human activities. Proposed changes associated with tropical agriculture could threaten the conservation status of these birds (Whitehead 1991). In attempting to sustain adequate numbers of a species, it is important to understand the species' reproductive biology. Unlike most water4E-mail: horn@science.canberra.edu.au fowl, Magpie Geese commonly form breeding trios consisting of two females and one male (Frith and Davies 1961). In situations where females share a nest, all three attendants typically have a direct reproductive (genetic) interest in the clutch, and they are involved in many aspects of care and defense of the eggs and young. Chicks remain with their parents for their first year of life, possibly learning about seasonal resource distribution (Whitehead and Tschirner 1990). The stability of these polygynous groups from year to year distinguishes Magpie Geese from other communal breeders (Brown 1987). When joined in a reproductive trio, individual females seem to decrease their potential reproductive output as measured by numbers of eggs laid. Egg counts (x = 8.6) in nests with only one female and one male are not much smaller than those (x = 9.4) from nests with two females and one male (Frith and Davies 1961). In addition, behavioral observations of trios suggest that males mate with both females and that both females contribute eggs approximately equally to these joint nests. Assignments of young to specific females have been done using restriction-fragment-length-polymorphism (RFLP) analysis of DNA. In making those assignments, conspecific nest parasitism was

A clinical evaluation in children of the Pharmacia ImmunoCAP system for inhalant allergens

Abstract: Summary Background The Pharmacia ImmunoCAP system (CAP) for assaying serum IgE specific antibodies was evaluated in a clinical setting against skin-prick test (SPT) perfonncd using Dome/Hollister-Steir allergen extracts. The five cotnmon inhalant allergens D. pteronyssinus. D. farinae, mould mix, grass mix and cat epithelium were tested concurrently by both methods in 167 children aged 7.5–12 years. The specific SPT for D. pteronyssinus and D. farinae were also tested against the CAP house dust mite (HDM) mix. Objective The purpose of the study was to determine the sensitivity and specificity of the Pharmacia ImmunoCAP system Tor detecting serum IgE specific antibodies to inhalant allergens in a clinical setting, using the SPT result as the ‘gold standard’. Methods The SPTs were performed using Dome/Hollister-Steir allergen extracts. The serum IgE specific antibodies were quantitated using the radioimmunoassay version of the Pharmacia ImmunoCAP system. A history of allergic disease was assessed using a validated questionnaire. Results SPT gave more positive reactions than CAP with the exception of cat epithelium. The concordance between SPT and CAP results was 91% over all the tests. The concordance with SPT was slightly higher for the specific CAP for D. pteronyssinus and D. farinae (93% and 95% respectively) than for the CAP HDM mix (86% and 90% respectively). There was a higher proportion of positive results for both SPT and CAP in the 115 children defined as having a history of allergic disease. Using SPT defined allergy as the gold standard, the sensitivity of the CAP system was 87% for the two specific house dust mites but was lower for cat epithelium (67%), mould mix (59%) and grass mix (46%). The sensitivity of the CAP system improved for D. pteronyssinus (96%) and the HDM mix (91%) when tested in subjects defined as having a history of allergy associated disease. The specificity of the CAP system showed less variation between allergens and ranged from 90–99%. Conclusion The results of this study of children aged 7.5–12 years demonstrate that, for the inhalent allergens tested, the Pharmacia ImmunoCAP system perfoms well in the setting of known allergic disease.

Pneumococcal antibody responses in elite swimmers

Abstract: The ability of elite swimmers to mount an antibody response to the pneumococcal vaccine, Pneumovax 23, was assessed at the end of an intensive 12-week training programme. Antibody titres to six pneumococcal polysaccharide types were measured in 20 elite swimmers (10 male, 10 female) aged 17-23 years and 19 sedentary age- and sex-matched students (eight male, 11 female) aged 18-23 years. Blood samples were tested 14 days apart to assess the magnitude of the antibody response and changes in serum immunoglobulin isotypes and IgG subclasses. There were no significant differences in any of the pneumococcal antibody responses to the Pneumovax between swimmers and controls, and no gender effect, either before or after vaccination. The clinically adequate response to the vaccine was greatest for the pneumococcal serotype 4, which was 97% for the total study population. There were no significant correlations between the magnitude of any of the pneumococcal antibody responses and (i) changes in the scores for the swimmers' international performance ; (ii) infection rates in either swimmers or controls ; (iii) any psychological variables, assessed by the Profile of Mood States (POMS) questionnaire for either swimmers or controls. Swimmers had significantly lower concentrations of serum IgG2 (P = 0.04) and IgG3 (P = 0.002) before pneumococcal vaccination. The swimmers had an increase in all immunoglobulin isotypes and IgG subclasses post-vaccination, suggesting a polyclonal response to the vaccine that was not observed in control subjects. The magnitude of the subclass responses after vaccination was significantly greater in swimmers compared with controls for IgG 1 (P = 0.04), IgG3 (P = 0.04) and IgG4 (P = 0.01). The data indicated that elite swimmers undertaking an intensive training programme were capable of mounting an antibody response to pneumococcal antigens equivalent to that of age- and sex-matched sedentary control subjects, despite the swimmers having lower prevaccination levels of serum immunoglobulins.

The production of activated carbon from a bituminous coal

Abstract: Devolatilization of an Illinois-basin coal was carried out under a nitrogen atmosphere in the temperature range 600 to 900°C. A vertical heated-wall fixed-bed furnace reactor was used. Char produced was activated in the presence and absence of steam using the same furnace setup. The surface area of the activated carbon produced was found to be equal to 54.4 m 2 g -1 when steam was absent and 226.2 m 2 g -1 when steam was present using the same process and conditions of activation. Breakthrough curves for the adsorption of toluene in water activated carbons prepared from that coal were obtained. They were compared with a commercially available activated carbon. On one hand, poor adsorptive properties were obtained for coal-carbons produced by the process of activation under oxygen-nitrogen gas atmospheres. On the other hand, it was found that good adsorption characteristics were obtained by using a steam-oxygen-nitrogen gas mixture. Following the preparation of activated carbon, it was necessary to treat the carbon produced in boiling distilled water. Boiling carbon in water for a short period of time (about 30 min), effectively improves the adsorption performance.

The photogalvanic effect of Fe(II)-β-diketonate/thionine systems in aqueous acetonitrile

Abstract: The photogalvanic effect of ferrousbis-(acetylacetonate) (Fe(II)(acac)2) and ferrousbis-(trifluoroacetylacetonate) (Fe(II)(tfac)2) complexes in aqueous acetonitrile thionine dye solutions has been studied in a photogalvanic cell of 70 cm3 capacity with identical platinum electrodes (area: 0.25 cm2) using visible light (80 mW/cm2) at 25°C. The theoretical Sunlight Engineering Efficiency (SEE) was determined for both complexes and it was found that the best SEE was obtained when Fe(II)(tfac)2 was used at a concentration of 1.5×10−4 mol/dm3 with a thionine concentration of 1×10−4 mol/dm3 atpH=4 in 40% aqueous acetonitrile. Effects of incident light intensity and temperature on the photogalvanic performance and the action spectrum of the present system were also investigated. A mechanism of the photoredox reaction between the Fe(II)-complex and the dye molecule is proposed.

Synthesis, characterization and cytotoxic activity of diorganotin (IV) complexes with 4H‐pyrido[1,2‐a]pyrimidin‐4‐one derivatives

Abstract: The coordination behaviour of the diorganotin(IV) compounds R 2 SnCl (where R = Me, Ph) with 4H-pyrido [1,2-a] pyrimidin-4-one derivatives (L) has been described. The complexes R 2 SnCl 2 .L obtained have been characterized physicochemically and spectroscopically. The pyrimidin-4-one ligands were found to coordinate with R 2 SnCl 2 species in a monodentate fashion, mainly via the oxygen atom of the 4-one group or possibly via the nitrogen atom of the -C=N linkage (the less sterically hindered nitrogen of the pyrimidine derivative) to give pentacoordinate tin complexes. Of the complexes selected to be screened against five tumour cell lines, some exhibited significant in vitro activity

Effect of Hydrogen Cyanide and Carbonyl Sulphide on the Germination and Plumule Vigour of Wheat

Abstract: Several factors which may influence the germination of wheat fumigated with hydrogen cyanide or carbonyl sulphide were investigated. Dosages of hydrogen cyanide ranged from 10 mg litre -1 for 24-h exposure up to 150 mg litre -1 for 96-h exposure. Dosages of carbonyl sulphide ranged from 25 mg litre -1 for 24-h exposure up to 500 mg litre -1 for 72-h exposure. The experiments were conducted on wheat of 11.4, 13.8 and 15.7% moisture content. The higher levels of these fumigants exceed those needed for control of insects in wheat. Germination was not diminished and may have been slightly enhanced with hydrogen cyanide, but was diminished by high levels of carbonyl sulphide in the drier wheat. The plumule length was reduced following all dosages of hydrogen cyanide, but only after high dosages of carbonyl sulphide, especially on the driest wheat. It is concluded that hydrogen cyanide and carbonyl sulphide could be used to control insects in wheat without affecting seed viability, provided that concentrations are carefully controlled.

A hardware/software codesign partitioner for ASIP design

Abstract: This paper introduces a new codesign partitioning method used in automating the design of ASIP (Application Specific Integrated Processor). The codesign partitioning problem is formalized as a combinatorial optimization problem that partitions the operations into hardware and software such that a certain performance goal is met using minimum hardware resources. A branch-and-bound algorithm is used to solve the presented formalization. The proposed method is found to be effective in producing a quality design in reasonable time with a minimum of design interaction.

Structural controls on the Cowarra gold deposit near Bredbo, southeastern New South Wales

Abstract: The Cowarra gold deposit is an epigenetic, structurally controlled, gold‐bearing sulfide vein system in a regional shear zone developed within isoclinally folded Ordovician turbidites. Gold occurs mainly in sulfide‐rich veins parallel to the axial cleavage or shears on fold limbs. There are seven sets of quartz veins, but they contain only minor gold. The mineralised shears lie within a zone of strong fold‐plunge variation, in the chlorite zone of a regional metamorphic complex, and to the west of the Bega Batholith. However, gold is not related to metamorphic outflushing, but more likely to sulfide‐rich fluids derived from depth during intrusion of I‐type granites of the Michelago Igneous Complex. The local control for sulfide veining was decompressional dilation of axial planar structures shortly after folding and shearing; this is unlike the structural control described for most deposits from this and similar terrains. Subsequent normal, strike‐slip and reverse fault movements in the shear zone develop...

The mass spectral fragmentation of some 2,3-dihydro-5-trifluoromethyl-7-( p-R -phenyl)-1,4-diazepines

Abstract: Electron impact mass spectra of seven 2,3-dihydro-5-trifluoromethyl/methyl-7-(p-R-phenyl)-1,4-diazepinesR=H, CH3, OCH3, CF3, Cl, Br) have been recorded and are discussed. These systems dissociate by scission of the C2-C3 bond followed by loss of H. to give the [M-H]+ ion as the base peak. The fragmentation behaviour has been investigated using metastable scanning techniques and accurate mass measurements. The origin of some characteristic fragment ions is discussed.

Self-organizing k-means classification algorithm

Abstract: A self-organizing k-means algorithm to classify the inputs (data) into classes is presented. This algorithm provides solutions to the problems that the k-means classification algorithm faces. The k-means classification algorithm has the problem of selecting the threshold(s). It also requires that the number of classes be known a priori. This algorithm forms clusters, removes noise, and is trained without supervision. The clustering is done on the basis of the statistical properties of the set of input data. The algorithm consists of two phases. The first phase is similar to the Carpenter/Grossberg classifier, and the second phase is a modified version of the k-means algorithm. An example is given to illustrate the application of this algorithm and to compare this algorithm with the k-means algorithm.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Out of control : the most effective way to help the binge-eating patient

Abstract: This article assessed the effectiveness of different treatments for bulimia nervosa by screening 400 studies published from 1987 through July 1933. Nineteen independent studies with a total of 1,015 subjects with 11 treatment types, and 316 subjects in 11 control groups fulfilled these criteria. Therapy outcome across studies was assessed meta-analytically, producing effect sizes that represent pretreatment to posttreatment changes in bulimic symptoms.

The Thermolysis of Benzyl Cobaloximes: A New One Step Synthesis of 5‐ Arylisoxazoles.

Abstract: When benzyl cobaloximes are either dry-distilled or boiled in xylene solution they afford the corresponding 5-arylisoxazoles in moderate to good yields.