12 research outputs found
The COMPASS Setup for Physics with Hadron Beams
The main characteristics of the COMPASS experimental setup for physics with
hadron beams are described. This setup was designed to perform exclusive
measurements of processes with several charged and/or neutral particles in the
final state. Making use of a large part of the apparatus that was previously
built for spin structure studies with a muon beam, it also features a new
target system as well as new or upgraded detectors. The hadron setup is able to
operate at the high incident hadron flux available at CERN. It is characterised
by large angular and momentum coverages, large and nearly flat acceptances, and
good two and three-particle mass resolutions. In 2008 and 2009 it was
successfully used with positive and negative hadron beams and with liquid
hydrogen and solid nuclear targets. This article describes the new and upgraded
detectors and auxiliary equipment, outlines the reconstruction procedures used,
and summarises the general performance of the setup.Comment: 91 pages, 101 figures and 7 table
Stereoselective Alkyne Hydrogenation by using a Simple Iron Catalyst
The stereoselective hydrogenation of alkynes constitutes one of the key approaches for the construction of stereodefined alkenes. The majority of conventional methods utilize noble and toxic metal catalysts. This study concerns a simple catalyst comprised of the commercial chemicals iron(II) acetylacetonate and diisobutylaluminum hydride, which enables the Z-selective semihydrogenation of alkynes under near ambient conditions (1-3 bar H-2, 30 degrees C, 5 mol % [Fe]). Neither an elaborate catalyst preparation nor addition of ligands is required. Mechanistic studies (kinetic poisoning, X-ray absorption spectroscopy, TEM) strongly indicate the operation of small iron clusters and particle catalysts
Stereoselective Chromium‐Catalyzed Semi‐Hydrogenation of Alkynes
Chromium complexes have found very little applications as hydrogenation catalysts. Here, we report a Cr-catalyzed semi-hydrogenation of internal alkynes to the correspondingZ-alkenes with good stereocontrol (up to 99/1 for dialkyl alkynes). The catalyst comprises the commercial reagents chromium(III) acetylacetonate, Cr(acac)(3), and diisobutylaluminium hydride, DIBAL-H, in THF. The semi-hydrogenation operates at mild conditions (1-5 bar H-2, 30 degrees C)
Bimetallic Co/Al nanoparticles in an ionic liquid: synthesis and application in alkyne hydrogenation
Herein, we report the microwave-induced decomposition of various organometallic cobalt and aluminum precursors in an ionic liquid (IL), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIm]NTf2), resulting in Co/Al nanoalloys with different molar Co/Al ratios. The dual-source precursor system of dicobalt octacarbonyl (Co2(CO)8) and pentamethylcyclopentadienyl aluminum ([AlCp*]4) in [BMIm]NTf2 afforded CoAl nanoparticles (CoAl-NPs) with a molar Co/Al ratio of 1 : 1. Their size and size distribution were determined via transmission electron microscopy (TEM) to be an average diameter of 3.0 ± 0.5 nm. Furthermore, the dual-source precursor system of cobalt amidinate ([Co(iPr2-MeAMD)2]) and aluminum amidinate [Me2Al(iPr2-MeAMD)] in molar ratios of 1 : 1 and 3 : 1 resulted in CoAl- and Co3Al-NPs with an average diameter of 3 ± 1 and 2.0 ± 0.2 nm, respectively. All the obtained materials were characterized via TEM, energy dispersive X-ray spectroscopy (EDX), selected area electron diffraction (SAED), together with high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and (high-resolution) X-ray photoelectron spectroscopy ((HR-)XPS). Phase-pure Co/Al-NPs were not obtained since the concomitant formation of Co-NPs and Al2O3 occurred in this wet-chemical synthesis. The as-prepared Co/Al nanoalloys were evaluated as catalysts in the hydrogenation of phenylacetylene under mild conditions (2 bar H2, 30 °C in THF). In comparison to the monometallic Co-NPs, the Co/Al-NPs showed a significantly higher catalytic hydrogenation activity. The Co- and Co/Al-NPs were also active under harsher reaction conditions (80 bar H2, 80 °C) without the addition of the activating co-catalyst DIBAL-H
The Susy Safe project overview after the first four years of activity
Objectives: to collect relevant, up-to-date, representative, accurate, systematic information, related to foreign bodies (FB) injuries. Methods: The "Susy Safe" registry, a DG SANCO co-funded project gathering data on choking in all EU Countries and beyond, was established in order to create surveillance systems for suffocation injuries able to provide a risk-analysis profile for each of the products causing the injury. Main findings after 4 years of activities are resumed here. Results: 16,878 FB injuries occurred in children aged 0-14 years have been recorded in the SUSY SAFE databases; 8046 cases have been reported from countries outside EU. Almost one quart of the cases involving very young children (less than one year of age) presented a FB located in bronchial tract, thus representing a major threat to their health. Esophageal foreign bodies are still characterizing injuries occurred to children younger than one year, in older children the most common locations are the ears and the nose. FB type was specified in 10,564 cases. Food objects represented the 26% of the cases, whereas non-food objects were the remaining 74%. Among food objects, the most common were bones, nuts and seed, whereas for the non-food objects pearls, balls and marbles were observed most commonly (29%). Coins were involved in 15% of the non-food injuries and toys represented the 4% of the cases. Conclusions: this data collection system should be been taken into consideration for the calculation of the risk of injuries in order to provide the EU Commission with all the relevant estimates on FB injurie
Bimetallic Co/Al nanoparticles in an ionic liquid: synthesis and application in alkyne hydrogenation
Injuries due to foreign body aspirations in Georgia: A prevention perspective
Background: Suffocation due to foreign bodies (FB) is a leading cause of death in children aged 0-3. No data from the former U.S.S.R. are available in the international scientific literature. Methods: Consecutive patients admitted at the Iashvili Central Children Hospital in Tbilisi, Georgia from 1989 to 2011 were analyzed. Injuries in the upper airways due to foreign bodies' inhalation were collected and compared with the Susy Safe Registry and the pooled estimates of the meta-analysis. Results: 2896 cases were collected. Distribution of injuries in children younger than 3 years was significantly higher than in the Susy Safe Registry and in the "High-Income" countries in the meta-analysis. Percentage of injuries due to organic objects (86%) was significantly higher than in published data. Conclusions: Since Georgia is not showing any substantial difference, both in epidemiology and treatment of foreign bodies injuries, as compared to the other case series, translation of public health initiatives from other most advanced prevention experiences is possible and it is likely to be effective. Level of evidence: Level V, Epidemiological case series. © 2015 Elsevier Ireland Ltd
Symptoms associated with button batteries injuries in children: An epidemiological review
Objectives: To provide an epidemiological framework of symptoms related to Foreign Body (FB) injuries due to Button Battery (BB). Methods: Data on BB ingestion/inhalation have been obtained from the ButtonBatteryDB. The ButtonBatteryDB is a database collecting information on BB injuries in children (0-18 years of age). Data on 348 BB injures have been derived from the Registry of Foreign Body Injuries "Susy Safe" (269 cases) and from published scientific literature reporting case reports of FB injuries (79 cases). Results: Most of injured children were male and BBs were found more often in the mouth/esophagus/stomach (ICD935) and in the nose (ICD932). Analyzing symptoms related to BB located in the esophagus/mouth/stomach, we found that children had higher probability of experiencing dysphagia (30.19%, 95% C.I. 17.83-42.55), fever and cough (26.42%, 95% C.I. 14.55-38.28), compared to the other symptoms. Referring to the probability that symptoms occurred simultaneously, fever and cough are more likely (3.72%, 95% C.I. 1.0-6-43) to jointly showing up in children with BB in mouth/esophagus/stomach (ICD935), followed by fever and dysphagia (2.66%, 95% C.I. 0.36-4.96) and by fever and irritability/crying, fever and drooling, dysphagia and irritability/crying (2.13% C.I. 0.00-4.19, 95% C.I.). Conclusions: These findings provide new insight in clinical presentation of BB injuries: the identification of unique patterns of symptoms related to BB injuries is useful to perform an early diagnosis (and to guarantee a prompt medical reaction), also when the injury is un-witnessed. © 2015 Elsevier Ireland Ltd