High-frequency atmospherically-induced oscillations in the middle Adriatic coastal area

Temporal and spatial characteristics of the resonant coupling between travelling air pressure disturbances and the middle Adriatic coastal waters are examined using a barotropic numerical model for a one year period (July 2000–July 2001). The model is forced by the travelling air pressure disturbances reconstructed from the 2-min resolution air pressure series measured at Split. Six experiments for the studied period are performed, in order to analyse the influence of the speed and disturbance direction on the resonant coupling. The first group of three experiments uses variable disturbance direction, whereas in the second three, a constant direction is employed during the whole experiment. Disturbance direction for the first group of experiments is computed from the 500-mb geopotential data provided by European Center for Medium Range Weather Forecast (ECMWF), as it is found that all of the past extreme events are correlated with them. Each experiment, with variable and constant disturbance direction, is repeated with three different constant values of 10, 20 and 30 m/s for the disturbance speed. The model verification on the Split sea level data reveals that the model reproduces most of the events but also overestimates/underestimates some of them and creates some false events due to the rigid assumption of a constant disturbance speed. The best agreement with data is obtained in the model runs assuming a disturbance speed of 20 m/s. A number of trapped and edge waves have been modelled at the constrictions and along the coast, in particular on a shoal that lies off Split perpendicular to the channel axis. The importance of the disturbance direction to the energy content is highlighted, particularly close to the shore, where the difference may be significant at 2–3 times on average, up to 30 cm in maximum amplitude

Characterizations of probability distributions via bivariate regression of record values

Bairamov et al. (Aust N Z J Stat 47:543-547, 2005) characterize the exponential distribution in terms of the regression of a function of a record value with its adjacent record values as covariates. We extend these results to the case of non-adjacent covariates. We also consider a more general setting involving monotone transformations. As special cases, we present characterizations involving weighted arithmetic, geometric, and harmonic means.Comment: accepted in Metrik

Electromagnetic Contributions to the Schiff Moment

The Schiff moment, \smij, is a parity and time reversal violating fermion-fermion coupling. The nucleus-electron Schiff moment generically gives the most important contribution to the electric dipole moments of atoms and molecules with zero net intrinsic electronic spin and nuclear spin ${1 \over 2}$. Here, the electromagnetic contribution to the Schiff moment, \emij, is considered. For a nucleon, the leading chirally violating contribution to this interaction is calculable in the chiral limit in terms of the parity and time reversal violating pion-nucleon coupling. For the Schiff moment of heavy nuclei, this chiral contribution is somewhat smaller than the finite size effect discussed previously in the literature.Comment: 7 pages, 1 figure (not included), Tex file, requires phyzzx, preprint SCIPP 93/4

Digitally Programmable Fully Differential Filter

In this paper a new digitally programmable voltage mode fully differential Kerwin-Huelsman-Newcomb(KHN) filter is realized using digitally controlled CMOS fully balanced output transconductor (DCBOTA). The realized filter uses five DCBOTAs, a single resistor and two capacitors. The filter provides low-pass, high-pass and band-pass responses simultaneously. The pole-frequency of all the responses is controlled by externally applying an 8- bit digital control word. All the responses exhibit independent digital control for pole-ω0 and pole-Q. The proposed filter also offers low passive sensitivities. Non-ideal gain and parasitic associated with the actual DCBOTA is also discussed. The CMMR results for low-pass response are also included which highlight the advantage of a fully-differential operation. Exhaustive PSPICE simulation is carried out using 0.5µ technology which may be further scaled to explore state-of-the-art applications of the proposed circuit

Prevalence of resistance associated polymorphisms in Plasmodium falciparum field isolates from southern Pakistan

<p>Abstract</p> <p>Background</p> <p>Scarce data are available on <it>Plasmodium falciparum </it>anti-malarial drug resistance in Pakistan. The aim of this study was, therefore, to determine the prevalence of <it>P. falciparum </it>resistance associated polymorphisms in field isolates from southern Pakistan.</p> <p>Methods</p> <p>Blood samples from 244 patients with blood-slide confirmed <it>P. falciparum </it>mono-infections were collected between 2005-2007. Single nucleotide polymorphisms in the <it>P. falciparum </it>chloroquine resistance transporter (<it>pfcrt </it>K76T), multi drug resistance (<it>pfmdr1 </it>N86Y), dihydrofolate reductase (<it>pfdhfr </it>A16V, N51I, C59R, S108N, I164L) and dihydropteroate synthetase (<it>pfdhps </it>A436S, G437A and E540K) genes and <it>pfmdr1 </it>gene copy numbers were determined using PCR based methods.</p> <p>Results</p> <p>The prevalence of <it>pfcrt </it>76T and <it>pfmdr1 </it>86Y was 93% and 57%, respectively. The prevalence of <it>pfdhfr </it>double mutations 59R + 108N/51R + 108N was 92%. The <it>pfdhfr </it>triple mutation (51I, 59R, 108N) occurred in 3% of samples. The <it>pfdhfr </it>(51I, 59R, 108N) and <it>pfdhps </it>(437G, 540E) quintuple mutation was found in one isolate. <it>Pfdhps </it>437G was observed in 51% and 540E in 1% of the isolates. One isolate had two <it>pfmdr1 </it>copies and carried the <it>pfmdr1 </it>86Y and <it>pfcrt </it>76T alleles.</p> <p>Conclusions</p> <p>The results indicate high prevalence of <it>in vivo </it>resistance to chloroquine, whereas high grade resistance to sulphadoxine-pyrimethamine does not appear to be widespread among <it>P. falciparum </it>in southern Pakistan.</p

Trade-off curves applications to support set-based design of a surface jet pump

Knowledge has become the most important asset of companies, especially in improving their product development processes. The set-based design approach is an efficient way of designing high quality, optimised designs. However, it requires a proven knowledge environment. Trade-off curves (ToCs) have the capability of providing the right knowledge and displaying it in a visual form. Although there are a few applications of ToCs that have recently been published in the literature, none of them demonstrates an integrated implementation of ToCs throughout the SBCE process. This paper presents the integrated use of ToCs, based on both physics-knowledge and proven knowledge, in order to compare and narrow down the design-set and to achieve an optimal design solution. These are key activities of the SBCE process model. Since an accurate, documented and visual knowledge environment is created by the use of ToCs within SBCE, the integrated approach proposed in this paper plays a vital role in eliminating the need for prototyping and testing at the early stages of product development. The integrated approach was implemented in an industrial case study for a surface jet pump. Surface jet pumps are used to increase the production rate of low-pressure oil/gas wells. It has been found that through ToCs, the conflicting relationships between the characteristics of the product can be understood and communicated effectively among the designers. This facilitated the decision-making on an optimal design solution in a remarkably short period of time. Furthermore, the surface jet pump resulting from the case study achieved an increase of the oil/gas production by nearly 60%