17 research outputs found
Fragmentation of very high energy heavy ions
A stack of CR39 (C12H18O7)n nuclear track detectors with a Cu target was
exposed to a 158 A GeV lead ion beam at the CERN-SPS, in order to study the
fragmentation properties of lead nuclei.
Measurements of the total, break-up and pick-up charge-changing cross
sections of ultrarelativistic Pb ions on Cu and CR39 targets are presented and
discussed.Comment: 4 pages, 3 EPS figures included with epsf, uses article.sty Talk
presented by M. Giorgini at the Int. Conf. on Structure of the Nucleus at the
Dawn of the Century, Bologna (Italy), May 29-June 3, 200
Fragmentation cross sections of Fe^{26+}, Si^{14+} and C^{6+} ions of 0.3-10 A GeV on CR39, polyethylene and aluminum targets
New measurements of the total and partial fragmentation cross sections in the
energy range 0.3-10 A GeV of Fe^{26+}, Si^{14+} and C^{6+} beams on
polyethylene, CR39 and aluminum targets are presented. The exposures were made
at Brookhaven National Laboratory (BNL), USA, and Heavy Ion Medical Accelerator
in Chiba (HIMAC), Japan. The CR39 nuclear track detectors were used to identify
the incident and survived beams and their fragments. The total fragmentation
cross sections for all targets are almost energy independent while they depend
on the target mass. The measured partial fragmentation cross sections are also
discussed.Comment: 4 pages, 5 eps figures. Talk given at the 24th International
Conference on Nuclear Tracks in Solids, Bologna, Italy, 1-5 September 200
Nuclear Track Detectors for Environmental Studies and Radiation Monitoring
Several improvements were made for Nuclear Track Detectors (NTDs) used for
environmental studies and for particle searches. A new method was used to
determine the bulk etch rate of CR39 and Makrofol NTDs. It is based on the
simultaneous measurement of the diameter and of the height of etch-pit cones
caused by relativistic heavy ions (158 A GeV Pb(82+) and In(49+) ions) and
their fragments. The use of alcohol in the etching solution improves the
surface quality of NTDs and it raises their thresholds. The detectors were used
for the determination of nuclear fragmentation cross sections of Iron and
Silicon ions of 1.0 and 0.41 GeV/nucleon. These measurements are important for
the determination of doses in hadron therapy and for doses received by
astronauts. The detectors were also used in the search of massive particles in
the cosmic radiation, for the determination of the mass spectrum of cosmic rays
and for the evaluation of Po(210) alpha decay and of natural radon
concentrations.Comment: 7 pages, 5 EPS figures. Presented at the 10th Topical Seminar on
Innovative Particle and Radiation Detectors, 1-5 October 2006, Siena, Ital
Search for strange quark matter and Q-balls with the SLIM experiment
We report on the search for Strange Quark Matter (SQM) and charged Q-balls
with the SLIM experiment at the Chacaltaya High Altitude Laboratory (5230 m
a.s.l.) from 2001 to 2005. The SLIM experiment was a 427 m array of
Nuclear Track Detectors (NTDs) arranged in modules of cm
area. SLIM NTDs were exposed to the cosmic radiation for 4.22 years after which
they were brought back to the Bologna Laboratory where they were etched and
analyzed. We estimate the properties and energy losses in matter of nuclearites
(large SQM nuggets), strangelets (small charged SQM nuggets) and Q-balls; and
discuss their detection with the SLIM experiment. The flux upper limits in the
CR of such downgoing particles are at the level of /cm/s/sr
(90% CL).Comment: 4 pages, 7 eps figures. Talk given at the 24th International
Conference on Nuclear Tracks in Solids, Bologna, Italy, 1-5 September 200
Bulk Etch Rate Measurements and Calibrations of Plastic Nuclear Track Detectors
New calibrations of CR39 and Makrofol nuclear track detectors have been
obtained using 158 A GeV Pb (82+) and In (49+) ions; a new method for the bulk
etch rate determination, using both cone height and base diameter measurements
was developed. The CR39 charge resolution based on the etch-pit base area
measurement is adequate to identify nuclear fragments in the interval 7 <=
Z/beta <= 49. For CR39 the detection threshold is at REL~50 MeV cm^2/g,
corresponding to a nuclear fragment with Z/beta~7. Base cone area distributions
for Makrofol foils exposed to Pb (82+) ions have shown for the first time all
peaks due to nuclear fragments with Z > 50; the distribution of the etched cone
heights shows well separated individual peaks for Z/beta = 78 - 83 (charge
pickup). The Makrofol detection threshold is at REL 2700 MeV cm^2/g,
corresponding to a nuclear fragment with Z/beta~50.Comment: 11 pages, 5 EPS figures. Submitted to Nucl. Instr. Meth.
Search for magnetic monopoles at the Chacaltaya cosmic ray laboratory
The new large area (400 m2) experiment—SLIM—to search for magnetic monopoles and other exotic massive particles is presented. It uses of nuclear track detectors and is being deployed at the Chacaltaya cosmic ray laboratory for at least 4 years. The detection capability of the experiment is discussed
Interdependence between the steel castings and manufacture of machines and equipment
Starting from the fact that the metallurgical industry is the main supplier of raw material both for the equipment and machines industry, as well as for the car industry, this paper analyses, by means of the regression function, to what extent the quantity of casting of steel was influenced, on the one hand by the manufacture of machines and equipment, and on the other hand, by the manufacture of car body. Data subject to the study were related to the period January 2002 – June 2016 (174 months) and was conducted both at the level of the European Union, as well as at the level of the main countries manufacturing steel at its level, namely: Germany, Italy, France and Spain
Influence of food matrix on inactivation of Bacillus cereus by combinations of nisin, pulsed electric field treatment, and carvacrol
Antibiotic resistance in community-acquired pneumonia. A romanian perspective
Community-acquired pneumonia (CAP) is one of the most common communicable diseases with a high mortality rate worldwide. Treatment is administered empirically based on clinical symptoms and the most commonly incriminated microorganisms in lower respiratory infections responsible for CAP. This study aimed to identify microorganisms responsible for CAP in patients hospitalized in an Emergency Hospital in Bucharest, Romania; to assess the impact of patients’ comorbidities and age on the survival level and to establish the degree of antimicrobial resistance of the most important isolated species. A total of 170 patients diagnosed with CAP from December 2017 through December 2018 were studied. Statistical analyses were performed considering the following data: survival rate, comorbidities, initiated pharmacotherapy, antibiogram results in case of refractory treatments. The overall survival rate was 36% among patients. Cardiovascular disease was incriminated as the highest risk factor. Concerning refractory antibiotic treatment, the microbiological results revealed that the most common bacterial strains detected were Klebsiella sp., Acinetobacter baumanii, S. aureus, E. coli and Pseudomonas, with high multiple antibiotic resistance (MAR) index. The results point out a real concern for patients with refractory CAP due to high antimicrobial resistance to the administered antibiotics in Romania. © 2020, Romanian Society for Pharmaceutical Sciences. All rights reserved