Non-destructive measurements of nA beam currents in particle beam storage rings by detecting the azimuthal magnetic field generated by moving charged particles with a Cryogenic Current Comparator ...(CCC) are well established. The detection of beam currents with small amplitudes with a CCC in a storage ring demands a high slew rate which is caused by the rapid change of the beam current exceeding the operational limit of the SQUID in flux-locked loop mode. Previous solutions to increase the slew rate used a LCR first-order low-pass filter were a small resistor, unfortunately, dominated the current noise of the CCC. In this work we present a novel take by adding a second resonator into the CCC which in turn allows for higher resistances of the LCR low-pass filter and therefore lower thermal current noise. A second challenge connected with this CCC approach is the residual magnetization of the highly permeable magnetic core and the resulting shielding currents in the superconducting circuits of the CCC. The timing of a storage ring in the range of minutes opens a way to reduce these DC currents using a LR high-pass filter. Using serial sub-micro ohm resistors, time constants in the hour range can be achieved to improve the stability and performance of the CCC system.
This article studies the impact of mechanical deformations on the performance of a coaxial-type cryogenic current comparator (CCC). Such deformations may become a concern as the size of the CCC ...increases (e.g., when used as a diagnostic device in a particle accelerator facility involving beamlines with a large diameter). In addition to static deformations, this article also discusses the effect of mechanical vibrations on the CCC performance.
is an important plant pathogen of many valuable crops worldwide, with more than 60 identified pathovars. The phytotoxins produced by these organisms were related to the severity of the damage caused ...to the plant. An emerging strategy to treat bacterial infections relies on interference with their signaling systems. In this study, we investigated
pv.
, which produces the virulence factor mangotoxin that causes bacterial apical necrosis on mango leaves. A previously unknown signaling molecule named leudiazen was identified, determined to be unstable and volatile, and responsible for mangotoxin production. A strategy using potassium permanganate, compatible with organic farming, was developed to degrade leudiazen and thus to attenuate the pathogenicity of
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At the radioactive ion beam facility REX-ISOLDE, neutron-rich zinc isotopes were investigated using low-energy Coulomb excitation. These experiments have resulted in B(E2,2{sub 1}{sup +}{yields}0{sub ...1}{sup +}) values in {sup 74-80}Zn, B(E2,4{sub 1}{sup +}{yields}2{sub 1}{sup +}) values in {sup 74,76}Zn and the determination of the energy of the first excited 2{sub 1}{sup +} states in {sup 78,80}Zn. The zinc isotopes were produced by high-energy proton- (A=74,76,80) and neutron- (A=78) induced fission of {sup 238}U, combined with selective laser ionization and mass separation. The isobaric beam was postaccelerated by the REX linear accelerator and Coulomb excitation was induced on a thin secondary target, which was surrounded by the MINIBALL germanium detector array. In this work, it is shown how the selective laser ionization can be used to deal with the considerable isobaric beam contamination and how a reliable normalization of the experiment can be achieved. The results for zinc isotopes and the N=50 isotones are compared to collective model predictions and state-of-the-art large-scale shell-model calculations, including a recent empirical residual interaction constructed to describe the present experimental data up to 2004 in this region of the nuclear chart.
A practical process was developed for the synthesis of 2‐difluoromethylpyridines via a Cu‐mediated Reductive Coupling‐Hydrolysis‐Decarboxylation sequence. The process employed 2‐bromopyridines with a ...variety of functional groups on the pyridine as substrates and used readily available and inexpensive starting materials. For operational safety DMSO shall not be considered as solvent and the use of DMF is recommended.
To di for: A practical process was developed for the synthesis of 2‐difluoromethylpyridines via a Cu‐mediated reductive coupling‐hydrolysis‐decarboxylation sequence. The process employed 2‐bromopyridines with a variety of functional groups on the pyridine as substrates and used readily available and inexpensive starting materials. For operational safety DMSO shall not be considered as solvent and the use of DMF is recommended.
Purpose
An overview of the current use of handwritten text recognition (HTR) on archival manuscript material, as provided by the EU H2020 funded Transkribus platform. It explains HTR, demonstrates ...Transkribus, gives examples of use cases, highlights the affect HTR may have on scholarship, and evidences this turning point of the advanced use of digitised heritage content. The paper aims to discuss these issues.
Design/methodology/approach
This paper adopts a case study approach, using the development and delivery of the one openly available HTR platform for manuscript material.
Findings
Transkribus has demonstrated that HTR is now a useable technology that can be employed in conjunction with mass digitisation to generate accurate transcripts of archival material. Use cases are demonstrated, and a cooperative model is suggested as a way to ensure sustainability and scaling of the platform. However, funding and resourcing issues are identified.
Research limitations/implications
The paper presents results from projects: further user studies could be undertaken involving interviews, surveys, etc.
Practical implications
Only HTR provided via Transkribus is covered: however, this is the only publicly available platform for HTR on individual collections of historical documents at time of writing and it represents the current state-of-the-art in this field.
Social implications
The increased access to information contained within historical texts has the potential to be transformational for both institutions and individuals.
Originality/value
This is the first published overview of how HTR is used by a wide archival studies community, reporting and showcasing current application of handwriting technology in the cultural heritage sector.
This paper studies the impact of mechanical deformations on the performance of a coaxial-type cryogenic current comparator (CCC). Such deformations may become a concern as the size of the CCC ...increases (e.g. when used as a diagnostic device in a particle accelerator facility involving beamlines with a large diameter). In addition to static deformations, this paper also discusses the effect of mechanical vibrations on the CCC performance.
Video content and, in particular, YouTube's content account for the largest amount of today's Internet traffic. However, little is known about the behavior of video streaming services for different ...kinds of network environments and under varying network conditions. Due to network operators' lack of knowledge about the transmitted content, network resources may not be optimally used in general. Thus, we propose a dyadic measurement system composed of application, i.e., client-based and network-based monitoring for YouTube's video traffic. Using our proposed monitoring methodology, we analyze the behavior of YouTube's HTTP-based adaptive video streaming mechanisms. In detail, we quantify via experimental measurements on real network traffic YouTube's behavior for different videos under static and varying network conditions. Our measurement results show that in case of varying network conditions, YouTube demands different video qualities in parallel in order to adapt to the network situation. However, this behavior can result in up to 33 % of redundant network traffic, i.e., downloaded video content of different quality levels for the same play time. Due to our findings, network operators should try to optimize the allocation of network resources for video content in a way that avoids varying network conditions, resulting in less waste of network resources.
Neutron-rich, radioactive Zn isotopes were investigated at the Radioactive Ion Beam facility REX-ISOLDE (CERN) using low-energy Coulomb excitation. The energy of the 2{sub 1}{sup +} state in {sup ...78}Zn could be firmly established and for the first time the 2{sup +}{yields}0{sub 1}{sup +} transition in {sup 80}Zn was observed at 1492(1) keV. B(E2,2{sub 1}{sup +}{yields}0{sub 1}{sup +}) values were extracted for {sup 74,76,78,80}Zn and compared to large scale shell model calculations. With only two protons outside the Z=28 proton core, {sup 80}Zn is the lightest N=50 isotone for which spectroscopic information has been obtained to date. Two sets of advanced shell model calculations reproduce the observed B(E2) systematics. The results for N=50 isotones indicate a good N=50 shell closure and a strong Z=28 proton core polarization. The new results serve as benchmarks to establish theoretical models, predicting the nuclear properties of the doubly magic nucleus {sup 78}Ni.
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