4,609 research outputs found

    T-odd correlations in charged Kl4 decays

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    We analyse the sensitivity to physics beyond the SM of T-odd correlations in Kℓ4K_{\ell 4} decays, which do not involve the lepton polarization. We show that a combined analysis of Kμ4+K^+_{\mu 4} and Kμ4−K^-_{\mu 4} decays can lead to new constraints about CP violation in ΔS=1\Delta S=1 charged-current interactions, complementary to those obtained from the transverse muon polarization in Kμ3K_{\mu 3} and of comparable accuracy.Comment: 6 pages (LaTeX

    Flexure-axial-shear interaction of ductile beams with single-crack plastic hinge behaviour

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    One of the key damage observations in modern reinforced concrete (RC) frame buildings, damaged following the 2010/2011 Canterbury and 2016 Kaikoura earthquakes, was localised cracking at the beam-column interface of capacity-designed beams. The localised cracking in the beams was due to curtailed longitudinal bars at the beam-column interface. Following these observations, without experimental data to justify desirable seismic performance, modern beams controlled by localised cracking were assumed to be potentially earthquake-vulnerable. To address this, an experimental program was carried out on six RC beam specimens susceptible to single-crack plastic hinge behaviour due to curtailed longitudinal bars. The experimental data show that RC beams with single-crack plastic hinge behaviour can undergo significant inelastic drift demands without loss of lateral resistance. However, contrary to conventional beams with distributed cracking, the response of RC beams with single-crack plastic hinge behaviour due to curtailed longitudinal bars is mainly dominated by hinge rotation (via bond-slip) and shear sliding at the column face. The current paper studies the interdependence of axial elongation, bond-slip and shear sliding deformation of RC beams with single-crack plastic hinge behaviour under cyclic demands. A procedure for seismic assessment of RC beams with single-crack plastic hinge behaviour due to curtailed longitudinal bars is proposed. The proposed formulations can be adopted to develop adequate numerical models for simulating the response of RC frames with beams susceptible to single-crack plastic hinge behaviour due to curtailed longitudinal bars

    Experience of some Iowa farmers with cattle feeding

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    The cattle feeder’s main purpose is to get the largest possible returns from his cattle with the amount of feed, capital and labor that he has available. Naturally, returns from the farm as a whole are more important than the success of any one enterprise, but the management of the entire farm involves many more questions than we can discuss adequately in this short bulletin. Therefore we shall simply present information obtained in 1938 and 1939 on the more common methods of Iowa cattle feeders. Results will be discussed solely on the basis of the cattle-feeding enterprise itself

    Seismic Performance of Reinforced Concrete Beams Susceptible to Single-Crack Plastic Hinge Behavior

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    Following the 2010/2011 Canterbury and 2016 Kaikoura earthquakes, a number of reinforced concrete (RC) beams in high-rise structures developed a single primary crack at the beam-column interface without the formation of distributed secondary cracks along the beam length. Detailed assessments showed that these beams have conforming longitudinal steel ratios and the single-crack mechanism may be due to design and/or construction practices for beam-column joints in the 1980s. In order to investigate the seismic behavior of reinforced concrete beams with detailing that inhibited the spread of flexural yielding, an experimental program was carried out on RC beam specimens, having similar reinforcement detailing to that of beams that developed a single crack at their ends during the Kaikoura earthquake to understand their seismic behavior, postearthquake repairability, and residual low-cycle fatigue life. Experimental results showed that the beams were able to undergo significant inelastic drift demands without loss of lateral resistance and have sufficient residual drift capacity following moderate and large earthquake demands. The response of the beam specimens was dominated by hinge rotation via the bond-slip mechanism. Comparisons showed that the measured drift capacities of the beams exceeded the predicted drift capacities computed using state-of-the-practice procedures

    Limit states for post-earthquake assessment and recovery analysis of ductile concrete components

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    Post-earthquake assessment procedures require component deformation limits to identify locations for visual inspection and locations needing structural repair. This study proposes a framework for defining component deformation limits for detailed visual inspection and repair for earthquake-damaged concrete buildings. First, observations from cyclic tests of ductile concrete components (beams, columns, and walls) suggested that the residual capacity (in terms of strength and deformation capacity) of such components is likely uncompromised if the deformation at the initiation of lateral strength loss (LSL) is not exceeded in prior loading histories. The results also revealed that the deformation at the initiation of LSL typically corresponds to the onset of longitudinal bar buckling in ductile components. Furthermore, using experimental data, multipliers are developed as fractions of ASCE/SEI 41 modeling parameters at lateral failure (i.e. a or d) to predict deformation at initiation of LSL. Subsequently, a probabilistic approach is proposed for defining the component deformation limits, considering uncertainty in both capacity and demand. Component deformation limits for detailed visual inspection are defined such that there is a low probability (adopted as <10%) of exceeding the deformation at the initiation of LSL. The component deformation limit for repair is defined as the median deformation at the initiation of LSL (i.e. 50% probability of exceedance)

    Final State Interactions and CP Violation in KL→π+π−e+e−K_L \to \pi^+ \pi^- e^+ e^-

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    Using chiral perturbation theory we calculate the imaginary parts of the KL→π+π−e+e−K_L \rightarrow \pi^+ \pi^- e^+ e^- form factors that arise from ππ→π+π−\pi \pi \rightarrow \pi^+ \pi^- and ππ→π+π−γ∗\pi \pi \rightarrow \pi^+ \pi^- \gamma^* rescattering. We discuss their influence on CP violating variables in KL→π+π−e+e−K_L \rightarrow \pi^+ \pi^- e^+ e^-.Comment: ; 12 pages, 2 figures, TeX format; uses epsf.tex, tables.tex, and phyzzx.te

    Nitrogen fixation, composition and growth of soybeans in relation to variable amounts of potassium and calcium

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    Publication authorized April 6, 1944.Includes bibliographical references (pages 35-36)

    Concept development of a Mach 4 high-speed civil transport

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    A study was conducted to configure and analyze a 250 passenger, Mach 4 High Speed Civil Transport with a design range of 6500 n.mi. The design mission assumed an all-supersonic cruise segment and no community noise or sonic boom constraints. The study airplane was developed in order to examine the technology requirements for such a vehicle and to provide an unconstrained baseline from which to assess changes in technology levels, sonic boom limits, or community noise constraints in future studies. The propulsion, structure, and materials technologies utilized in the sizing of the study aircraft were assumed to represent a technology availability date of 2015. The study airplane was a derivative of a previously developed Mach 3 concept and utilized advanced afterburning turbojet engines and passive airframe thermal protection. Details of the configuration development, aerodynamic design, propulsion system, mass properties, and mission performance are presented. The study airplane was estimated to weigh approx. 866,000 lbs. Although an aircraft of this size is a marginally acceptable candidate to fit into the world airport infrastructure, it was concluded that the inclusion of community noise or sonic boom constraints would quickly cause the aircraft to grow beyond acceptable limits using the assumed technology levels
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