Action of Thionyl Chloride on Urethanes (Abstract)

Raiford and Shelton [J. Org. Chem., 4, 207 (1939)] found that hot pyridine causes 2-carbophenoxyamino-4-methy 1-6-bromophenyl p-tolylsulfonate to lose phenol and give a condensation product which was found to be a 1,3- derivative of uretedione (uretidone). This type of derivative was also obtained by Warren and Wilson [Ber., 68, 957 (1935) J by the action of thionyl chloride on phenylurethane. But it has now been found that the last-named reaction is specific for phenylure thane. When the phenyl radical contains a negative substituent, thionyl chloride causes no action after five hours refluxing. If the substituent is alkyl the treatment causes tar formation, from which nothing definite could be isolated. Ethyl and n-butyl carbamates react with thionyl chloride to give the corresponding esters of allophanic acid and small amounts of cyanuric acid. Under the same treatment 2-naphthylurethane undergoes chlorination to give the 1-chloro derivative, while the 1-naphthyl compound gives the 4-chloro derivative

Formation and Properties of Some Uretediones

ofmann (Ber., 4, 246. 1871.) found that triethylphosphine served as a catalyst to cause the polymerization of phenyl isocyanate to a dimer which he designated as diphenyl diisocyanate. Staudinger ( Die Ketene , Enke, Stuttgart, 1912, p. 126.) regarded this product as a four atomic ring derivative. It has now been found that triethylphosphine polymerizes a number of substituted phenylisocyanates, such as λ- and β-naphthyl isocyanates, and p-xenyl isocyanate. These products which have more recently been listed as derivatives of uretedione, react with aliphatic amines to produce substituted biurets

First Results for the Beam Commissioning of the CERN Multi-Turn Extraction

The Multi-Turn Extraction (MTE), a new type of extraction based on beam trapping inside stable islands in horizontal phase space, has been commissioned during the 2008 run of the CERN Proton Synchrotron. Both singleand multi-bunch beams with a total intensity up to 1.4 1013 protons have been extracted with efficiencies up to 98%. Furthermore, injection tests in the CERN Super Proton Synchrotron were performed, with the beam then accelerated and extracted to produce neutrinos for the CERN Neutrino-to-Gran Sasso experiments. The results of the extensive measurement campaign are presented and discussed in detail

The BGO Calorimeter of BGO-OD Experiment

The BGO Rugby Ball is a large solid angle electromagnetic calorimeter now installed in the ELSA Facility in Bonn. The BGO is operating in the BGO-OD experiment aiming to study meson photoproduction off proton and neutron induced by a Bremsstrahlung polarized gamma beam of energies from 0.2 to 3.2 GeV and an intensity of 5 x 10(7) photons per second. The scintillating material characteristics and the photomultiplier read-out make this detector particularly suited for the detection of medium energy photons and electrons with very good energy resolution. The detector has been equipped with a new electronics read-out system, consisting of 30 sampling ADC Wie-Ne-R modules which perform the off-line reconstruction of the signal start-time allowing for a good timing resolution. Performances in linearity, resolution and time response have been carefully tested at the Beam Test Facility of the INFN National Laboratories in Frascati by using a matrix of 7 BGO crystals coupled to photomultipliers and equipped with the Wie-Ne-R sampling ADCs

Latest Developments of the PUNCH4NFDI Compute and Storage Infrastructures

The PUNCH4NFDI consortium, funded by the German Research Foundation for an initial period of five years, gathers various physics communities - particle, astro-, astroparticle, hadron and nuclear physics - from different institutions embedded in the National Research Data Infrastructure initiative. The goal of PUNCH4NFDI is the establishment of FAIR data management solutions for the participating communities. The federated compute and storage infrastructures made available to the consortium, Compute4PUNCH and Storage4PUNCH, comprise a variety of heterogeneous compute and storage systems. The compute resources are managed by an overlay batch system and COBalD/TARDIS meta-schedulers. The TARDIS resource manager is responsible for the provisioning of resources and their integration in the overlay batch system based on HTCondor, while the COBalD resource balancer optimises the resource utilization by matching the actual demand for a given type of resources. The access to the resources is standardised using a token-based authentication and authorization infrastructure. The refreshment of short-lived access tokens is automated using the HTCondor Credential Manager and the MyToken service. Login nodes define single entry points to the federation, while the use of containers and the CERN Virtual Machine File System ensures a scalable provisioning of virtualized software environments. The latest developments are presented, including the access tokens management and the integration of Compute4PUNCH as a compute backend of the REANA analysis platform

Coherent π0ηd\pi^0\eta d photoproduction at forward deuteron angles measured at BGOOD

The coherent reaction, $\gamma d \rightarrow \pi^0\eta d$ was studied with the BGOOD experiment at ELSA from threshold to a centre-of-mass energy of 3200\,MeV. A full kinematic reconstruction was made, with final state deuterons identified in the forward spectrometer and $\pi^0$ and $\eta$ decays in the central BGO Rugby Ball. The strength of the differential cross section exceeds what can be described by models of coherent photoproduction at forward angles by orders of magnitude. The distribution of the differential cross section has an excellent agreement with a model including quasi-free $\Delta \pi$ photoproduction, pion re-scattering and $N(1535)$ formation and subsequent nucleon coalescence to the deuteron. This also gives a reasonable description of the two-body invariant mass distributions and naturally explains the similar magnitudes of this channel and $\pi^0\pi^0 d$ coherent photoproduction.Comment: 7 pages, 5 figure

Room-Temperature Magnetic Skyrmions in Pt/Co/Cu Multilayers

Magnetic skyrmions are promising for next-generation information storage and processing owing to their potential advantages in data storage density, robustness, and energy efficiency. The magnetic multilayers consisting of Pt, Co, and a third metal element $X$ provide an ideal platform to study the skyrmions due to their highly tunable magnetic properties. Here, we report the observation of room-temperature bubble-like Néel skyrmions in epitaxial Pt/Co/Cu multilayers in samples with multidomain states in zero field. The magneto-optic Kerr effect (MOKE) and superconducting quantum interference device (SQUID) magnetometry are applied to investigate the shapes of the hysteresis loops, the magnetic anisotropy, and the saturation magnetization. By tuning the Co thickness and the number of periods, we achieve perpendicular and in-plane magnetized states and multidomain states that are identified by a wasp-waisted hysteresis loop. Skyrmions are directly imaged by magnetic force microscopy (MFM) and Lorentz transmission electron microscopy (LTEM). The development of room-temperature skyrmions in Pt/Co/Cu multilayers may lead to advances in skyrmion-related research and applications.11 pages, 6 Figure

Evidence of a dibaryon spectrum in coherent π0π0d photoproduction at forward deuteron angles

The coherent reaction, was studied with the BGOOD experiment at ELSA from threshold to a centre-of-mass energy of 2850 MeV. A full kinematic reconstruction was made, with final state deuterons identified in the forward spectrometer and decays in the central BGO Rugby Ball. The strength of the differential cross section exceeds what can be described by models of coherent photoproduction and instead supports the three isoscalar dibaryon candidates reported by the ELPH collaboration at 2.38, 2.47 and 2.63 GeV/c2. A low mass enhancement in the invariant mass is also observed at the ⁎ centre-of-mass energy which is consistent with the ABC effect. At higher centre-of-mass energies, a narrow peak in the invariant mass at 2114 MeV/c2 with a width of 20 MeV/c2 supports a sequential two-dibaryon decay mechanism