134 research outputs found
Compressive load bearing and bone architecture of lumbar vertebrae in terms of sex and aging
Relation between vertebral compressive strength and trabecular architecture is presented in terms of aging and sex. Complex in vitro medical-engineering analysis of cadaver human lumbar L1 and L2 vertebrae was executed: densitometry, CT, MRI, mechanical test and histology, in aspect of osteoporosis. In this paper the results of the mechanical test are detailed only. The compressive mechanical parameters, like limit stress and strain, proportional stress and strain, Young modulus, ductility, energy absorption capacity were determined. Morphometry analysis was based on the CT pictures. Density and diameter of trabeculae were measured. Correlation between morphometric and mechanical properties was evaluated in terms of aging, sex and bone mineral density
Penalty Methods for the Hyperbolic System Modelling the Wall-Plasma Interaction in a Tokamak
The penalization method is used to take account of obstacles in a tokamak,
such as the limiter. We study a non linear hyperbolic system modelling the
plasma transport in the area close to the wall. A penalization which cuts the
transport term of the momentum is studied. We show numerically that this
penalization creates a Dirac measure at the plasma-limiter interface which
prevents us from defining the transport term in the usual sense. Hence, a new
penalty method is proposed for this hyperbolic system and numerical tests
reveal an optimal convergence rate without any spurious boundary layer.Comment: 8 pages; International Symposium FVCA6, Prague : Czech Republic
(2011
Characteristics and empiric antimicrobial therapy of urinary tract infections in patients treated at the Departement of Infectious Diseases, General Hospital »Dr. Josip Benčević« in Slavonski Brod
Infekcije mokraćnog sustava (IMS) jedan su od najčešćih razloga traženja liječničke pomoći, pa stoga i među najčešćim razlozima propisivanja antibiotika. Istaknuta je analiza najčešćih uzročnika IMS u našoj sredini, uočavanje stupnja rezistencije na pojedine antibiotike, te ocjena uspješnosti ordinirane empirijske antimikrobne terapije. Retrospektivno su obrađeni podaci o bolesnicima liječenim na Odjelu za zarazne bolesti Opće bolnice »Dr. Josip Benčević« u Slavonskom Brodu, zbog akutnih infekcija mokraćnog sustava, tijekom 2004. godine. Najčešći je uzročnik IMS bila Escherichia coli, premda je u muškaraca s kompliciranim IMS bio najčešći uzročnik Pseudomonas aeruginosa. Obzirom da je 45 % izoliranih bakterija Escherichia coli bilo rezistentno na amoksicilin, a 35 % na kotrimoksazol, ovi antibiotici se u našoj sredini ne mogu upotrebljavati u empirijskoj antimikrobnoj terapiji IMS. Čak 65 % izoliranih bakterija Pseudomonas aeruginosa nije bilo osjetljivo na gentamicin, a 45 % na ciprofloksacin. Najčešći neuspjeh empirijske antimikrobne terapije zabilježen je u muškaraca s kompliciranim IMS, pa bi nam bio najbolji izbor empirijskog antimikrobnog liječenja ovih bolesnika kombinacija piperacilina s tazobaktamom, karbapenemi ili cefepim.Urinarv tract infections (UTI) are one of the most common reasons for seeking medical consultation and therefore are among the most frequent reasons for antibiotic prescription. The purpose of this paper is the analvsis of the most common etiologic agents of UTI in our environment, registration of the degree of bacterial resistance, and evaluation of empiric antibiotic therapv success. Retrospectively data of patients, hospitalized during year 2004, at the Departement of Infectious Diseases, General Hospital »Dr. Josip Benčević« in Slavonski Brod, due to acute urinarv tract infections, were analysed. The most common cause of UTI was Escherichia coli, although in male patients with complicated UTI, the most common cause was Pseudomonas aeruginosa. Since 45% of Escherichia coli were amoxicillin resistant, and 35% trimethoprim-sulfamethoxazole resistant, these antimicrobials can\u27t be used as empiric therapy drugs in our environment. As much as 65% of Pseudomonas aeruginosa were gentamicin and 45% ciprofloxacin resistant. The most frequent empiric antibiotic therapy failure was observed in male patients with complicated UTI, so the best empiric drug choice for these patients, in our situation, would be piperacillin/tazobactam, carbapenems or cefepime
Analysis of noise temperature sensitivity for the design of a broadband thermal noise primary standard
A broadband primary standard for thermal noise measurements is presented and its thermal and electromagnetic behaviour is analysed by means of a novel hybrid analytical?numerical simulation methodology. The standard consists of a broadband termination connected to a 3.5mm coaxial airline partially immersed in liquid nitrogen and is designed in order to obtain a low reflectivity and a low uncertainty in the noise temperature. A detailed sensitivity analysis is made in order to highlight the critical characteristics that mostly affect the uncertainty in the noise temperature, and also to determine the manufacturing and operation tolerances for a proper performance in the range 10MHz to 26.5 GHz. Aspects such as the thermal bead design, the level of liquid nitrogen or the uncertainties associated with the temperatures, the physical properties of the materials in the standard and the simulation techniques are discussed
Measurement of polarisation observables in photoproduction off the proton
The reaction is studied in the
photon energy range from threshold. Linearly polarised photon beams from
coherent bremsstrahlung enabled the first measurement of photon beam
asymmetries in this reaction up to MeV. In addition, the
recoil hyperon polarisation was determined through the asymmetry in the weak
decay up to MeV. The data are
compared to partial wave analyses, and the possible impact on the
interpretation of a recently observed cusp-like structure near the
thresholds is discussed.Comment: 6 pages, 5 figures. References [8,9,10,11] which were not on the
original submission are now include
K^0 pi^0 Sigma^+ and K^*0 Sigma^+ photoproduction off the proton
The exclusive reactions and , leading to the p 4 final state, have
been measured with a tagged photon beam for incident energies from threshold up
to 2.5 GeV. The experiment has been performed at the tagged photon facility of
the ELSA accelerator (Bonn). The Crystal Barrel and TAPS detectors were
combined to a photon detector system of almost 4 geometrical acceptance.
Differential and total cross sections are reported. At energies close to the
threshold, a flat angular distribution has been observed for the reaction
suggesting dominant s-channel production.
and higher lying hyperon states have been observed. An
enhancement in the forward direction in the angular distributions of the
reaction indicates a -channel exchange
contribution to the reaction mechanism. The experimental data are in reasonable
agreement with recent theoretical predictions.Comment: 11 pages, 13 figures, submitted to EPJ
Experimental constraints on the -nucleus real potential
In a search for mesic states, the production of -mesons in
coincidence with forward going protons has been studied in photon induced
reactions on C for incident photon energies of 1250 - 3100 MeV. The
pairs from decays of bound or quasi-free -mesons have
been measured with the CBELSA/TAPS detector system in coincidence with protons
registered in the MiniTAPS forward array. Structures in the total energy
distribution of the pairs, which would indicate the population
and decay of bound B states, are not observed. The
cross section of 0.3 nb/MeV/sr observed in the bound state energy regime
between -100 and 0 MeV may be accounted for by yield leaking into the bound
state regime because of the large in-medium width of the -meson. A
comparison of the measured total energy distribution with calculations suggests
the real part of the B potential to be small and only
weakly attractive with 35(stat) 20(syst) MeV
in contrast to some theoretical predictions of attractive potentials with a
depth of 100 - 150 MeV.Comment: 13 pages, 8 figure
First measurement of the helicity asymmetry for in the resonance region
The first measurement of the helicity dependence of the photoproduction cross
section of single neutral pions off protons is reported for photon energies
from 600 to 2300\,MeV, covering nearly the full solid angle. The data are
compared to predictions from the SAID, MAID, and BnGa partial wave analyses.
Strikingly large differences between data and predictions are observed which
are traced to differences in the helicity amplitudes of well known and
established resonances. Precise values for the helicity amplitudes of several
resonances are reported
Photoproduction of eta mesons from the neutron: cross sections and double polarization observable E
Photoproduction of mesons from neutrons} \abstract{Results from
measurements of the photoproduction of mesons from quasifree protons and
neutrons are summarized. The experiments were performed with the CBELSA/TAPS
detector at the electron accelerator ELSA in Bonn using the
decay. A liquid deuterium target was used for the
measurement of total cross sections and angular distributions. The results
confirm earlier measurements from Bonn and the MAMI facility in Mainz about the
existence of a narrow structure in the excitation function of . The current angular distributions show a forward-backward
asymmetry, which was previously not seen, but was predicted by model
calculations including an additional narrow state. Furthermore, data
obtained with a longitudinally polarized, deuterated butanol target and a
circularly polarized photon beam were analyzed to determine the double
polarization observable . Both data sets together were also used to extract
the helicity dependent cross sections and . The
narrow structure in the excitation function of
appears associated with the helicity-1/2 component of the reaction
The N(1520) 3/2- helicity amplitudes from an energy-independent multipole analysis based on new polarization data on photoproduction of neutral pions
New data on the polarization observables T, P, and H for the reaction are reported. The results are extracted from azimuthal
asymmetries when a transversely polarized butanol target and a linearly
polarized photon beam are used. The data were taken at the Bonn electron
stretcher accelerator ELSA using the CBELSA/TAPS detector. These and earlier
data are used to perform a truncated energy-independent partial wave analysis
in sliced-energy bins. This energy-independent analysis is compared to the
results from energy-dependent partial wave analyses
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