42 research outputs found
Tartaric Acid Synthetic Derivatives for Multi-Drug Resistant Phytopathogen Pseudomonas and Xanthomonas Combating
The resistance to antimicrobial preparations, according the WHO reports of recent years, is becoming the one of the most actual healthcare problems of this century. Nevertheless, the key role of antibiotics diversity increase, as well as the increase of their application scopes, the initial origin of antimicrobial resistance problem is the versatility of adaptation mechanisms potential of all microorganisms, including intraspecific gene horizontal transfer and quorum sensing. Thus, the actuality of search of new, ecologically safe and harmless for human health antimicrobial agents, among the natural and semisynthetic compounds, is being significantly increased. One of the prospective directions in these research is the derivatization of aldaric acids, isolated from plants different species, as the native antibacterial active substances, such as like: citric, acetic, tartaric, lactic.
In current research, 7 new derivatives of natural tartaric acid (TA): cyclohexylimide, benzylimide, phenylimide, benzyl mono amino salt, cyclohexyl mono amino salt, phenyl amino salt and mono ethanol amino salt of TA were tested on different strains from 6 subtypes of 3 species of phytopathogenic multi-drug resistant Xanthomonas and Pseudomonas. During the research it was detected the significant antimicrobial effect of studied compounds against the range of phytopathogens which are resistant to antibiotics from different classes and generations (ciprofloxacin, chloramphenicol, ceftriaxone, azithromycin, etc.). It was detected the higher efficiency of cyclohexyl- derivatives in comparison with mono ethanol-, phenyl- and benzyl- derivatives
Measurement of charged particle spectra in deep-inelastic ep scattering at HERA
Charged particle production in deep-inelastic ep scattering is measured with the H1 detector at HERA. The kinematic range of the analysis covers low photon virtualities, 5 LT Q(2) LT 100 GeV2, and small values of Bjorken-x, 10(-4) LT x LT 10(-2). The analysis is performed in the hadronic centre-of-mass system. The charged particle densities are measured as a function of pseudorapidity (n(*)) and transverse momentum (p(T)(*)) in the range 0 LT n(*) LT 5 and 0 LT p(T)(*) LT 10 GeV in bins of x and Q(2). The data are compared to predictions from different Monte Carlo generators implementing various options for hadronisation and parton evolutions
Measurement of Inclusive ep Cross Sections at High at = 225 and 252 GeV and of the Longitudinal Proton Structure Function at HERA
Inclusive ep double differential cross sections for neutral current deep inelastic scattering are measured with the H1 detector at HERA. The data were taken with a lepton beam energy of 27.6 GeV and two proton beam energies of Ep = 460 and 575 GeV corresponding to centre-of-mass energies of 225 and 252 GeV, respectively. The measurements cover the region of 6.5 *10^{-4}<=x<= 0.65 for 35<=Q^2<=800 GeV^2 up to y = 0.85. The measurements are used together with previously published H1 data at Ep = 920 GeV and lower Q2 data at Ep = 460, 575 and 920 GeV to extract the longitudinal proton structure function FL in the region 1.5<=Q^2 <=800 GeV^2
Erratum to: Measurement of jet production cross sections in deep-inelastic ep scattering at HERA
The measurement of the jet cross sections by the H1 collaboration had been compared to various predictions including the next-to-next-to-leading order (NNLO) QCD calculations which are corrected in this erratum for an implementation error in one of the components of the NNLO calculations. The jet data and the other predictions remain unchanged. Eight figures, one table and conclusions are adapted accordingly, exhibiting even better agreement between the corrected NNLO predictions and the jet data
Diffractive Dijet Production with a Leading Proton in ep Collisions at HERA
The cross section of the diffractive process e^+p -> e^+Xp is measured at a centre-of-mass energy of 318 GeV, where the system X contains at least two jets and the leading final state proton p is detected in the H1 Very Forward Proton Spectrometer. The measurement is performed in photoproduction with photon virtualities Q^2 <2 GeV^2 and in deep-inelastic scattering with 4 GeV^2<Q^2<80 GeV^2. The results are compared to next-to-leading order QCD calculations based on diffractive parton distribution functions as extracted from measurements of inclusive cross sections in diffractive deep-inelastic scattering
Measurement of Jet Production Cross Sections in Deep-inelastic ep Scattering at HERA
A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities and inelasticities is presented, using data taken with the H1 detector at HERA, corresponding to an integrated luminosity of . Double-differential inclusive jet, dijet and trijet cross sections are measured simultaneously and are presented as a function of jet transverse momentum observables and as a function of . Jet cross sections normalised to the inclusive neutral current DIS cross section in the respective -interval are also determined. Previous results of inclusive jet cross sections in the range are extended to low transverse jet momenta . The data are compared to predictions from perturbative QCD in next-to-leading order in the strong coupling, in approximate next-to-next-to-leading order and in full next-to-next-to-leading order. Using also the recently published H1 jet data at high values of , the strong coupling constant is determined in next-to-leading order.A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities and inelasticities is presented, using data taken with the H1 detector at HERA, corresponding to an integrated luminosity of . Double-differential inclusive jet, dijet and trijet cross sections are measured simultaneously and are presented as a function of jet transverse momentum observables and as a function of . Jet cross sections normalised to the inclusive neutral current DIS cross section in the respective -interval are also determined. Previous results of inclusive jet cross sections in the range are extended to low transverse jet momenta . The data are compared to predictions from perturbative QCD in next-to-leading order in the strong coupling, in approximate next-to-next-to-leading order and in full next-to-next-to-leading order. Using also the recently published H1 jet data at high values of , the strong coupling constant is determined in next-to-leading order.A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities and inelasticities is presented, using data taken with the H1 detector at HERA, corresponding to an integrated luminosity of . Double-differential inclusive jet, dijet and trijet cross sections are measured simultaneously and are presented as a function of jet transverse momentum observables and as a function of . Jet cross sections normalised to the inclusive neutral current DIS cross section in the respective -interval are also determined. Previous results of inclusive jet cross sections in the range are extended to low transverse jet momenta . The data are compared to predictions from perturbative QCD in next-to-leading order in the strong coupling, in approximate next-to-next-to-leading order and in full next-to-next-to-leading order. Using also the recently published H1 jet data at high values of , the strong coupling constant is determined in next-to-leading order
Colombeau generalized functions on manifolds
Eduard NigschZsfassung in dt. SpracheWien, Techn. Univ. u. Univ., Dipl.-Arb., 2006OeBB(VLID)161012
Exclusive Meson Photoproduction with a Leading Neutron at HERA
A first measurement is presented of exclusive photoproduction of mesons associated with leading neutrons at HERA. The data were taken with the H1 detector in the years and at a centre-of-mass energy of GeV and correspond to an integrated luminosity of pb. The mesons with transverse momenta , are detected in the Forward Neutron Calorimeter. The phase space of the measurement is defined by the photon virtuality GeV, the total energy of the photon-proton system GeV and the polar angle of the leading neutron mrad. The cross section of the reaction is measured as a function of several variables. The data are interpreted in terms of a double peripheral process, involving pion exchange at the proton vertex followed by elastic photoproduction of a meson on the virtual pion. In the framework of one-pion-exchange dominance the elastic cross section of photon-pion scattering, , is extracted. The value of this cross section indicates significant absorptive corrections for the exclusive reaction
Measurement of Dijet Production in Diffractive Deep-Inelastic ep Scattering at HERA
A measurement is presented of single- and double-differential dijet cross sections in diffractive deep-inelastic scattering at HERA using data collected by the H1 experiment corresponding to an integrated luminosity of 290 pb^{-1}. The investigated phase space is spanned by the photon virtuality in the range of 4<Q^{2}<100 GeV^{2} and by the fractional proton longitudinal momentum loss x_pom<0.03. The resulting cross sections are compared with next-to-leading order QCD predictions based on diffractive parton distribution functions and the value of the strong coupling constant is extracted