At the Large Hadron Collider (LHC), absolute luminosity calibrations obtained by the van der Meer (
vdM
) method are affected by the mutual electromagnetic interaction of the two beams. The colliding ...bunches experience relative orbit shifts, as well as optical distortions akin to the dynamic-
β
effect, that both depend on the transverse beam separation and must therefore be corrected for when deriving the absolute luminosity scale. In the
vdM
regime, the beam–beam parameter is small enough that the orbit shift can be calculated analytically. The dynamic-
β
corrections to the luminometer calibrations, however, had until the end of Run 2 been estimated in the linear approximation only. In this report, the influence of beam–beam effects on the
vdM
-based luminosity scale is quantified, together with the associated systematic uncertainties, by means of simulations that fully take into account the non-linearity of the beam–beam force, as well as the resulting non-Gaussian distortions of the transverse beam distributions. Two independent multiparticle simulations, one limited to the weak-strong approximation and one that models strong-strong effects in a self-consistent manner, are found in excellent agreement; both predict a percent-level shift of the absolute
pp
-luminosity values with respect to those assumed until recently in the physics publications of the LHC experiments. These results also provide guidance regarding further studies aimed at reducing the beam–beam-related systematic uncertainty on beam–beam corrections to absolute luminosity calibrations by the van der Meer method.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The article reports results from the largest international dose survey in paediatric computed tomography (CT) in 32 countries and proposes international diagnostic reference levels (DRLs) in terms of ...computed tomography dose index (CTDI vol) and dose length product (DLP). It also assesses whether mean or median values of individual facilities should be used. A total of 6115 individual patient data were recorded among four age groups: <1 y, >1-5 y, >5-10 y and >10-15 y. CTDIw, CTDI vol and DLP from the CT console were recorded in dedicated forms together with patient data and technical parameters. Statistical analysis was performed, and international DRLs were established at rounded 75th percentile values of distribution of median values from all CT facilities. The study presents evidence in favour of using median rather than mean of patient dose indices as the representative of typical local dose in a facility, and for establishing DRLs as third quartile of median values. International DRLs were established for paediatric CT examinations for routine head, chest and abdomen in the four age groups. DRLs for CTDI vol are similar to the reference values from other published reports, with some differences for chest and abdomen CT. Higher variations were observed between DLP values, based on a survey of whole multi-phase exams. It may be noted that other studies in literature were based on single phase only. DRLs reported in this article can be used in countries without sufficient medical physics support to identify non-optimised practice. Recommendations to improve the accuracy and importance of future surveys are provided.
ABSTRACT The objective of this study was to compare the internal and external quality of conventional and designer eggs. In total, 120 Tetra SL laying hens were randomly allotted to two treatments (K ...and P groups), with 12 replicates of five hens each. The control group (K) was fed a standard layer diet, producing conventional eggs, and the P group was fed a modified diet supplemented with 5% of an oil mixture, 0.5 mg organic selenium/kg, 200 mg lutein/kg and 200 mg vitamin E/kg, producing designer eggs. Treatments did not influence (p>0.05) egg weight or egg component weights. Designer eggs presented higher albumen proportion and lower eggshell proportion than conventional eggs (p<0.01). Relative to egg quality parameters, designer eggs presented higher HU values (83.99 vs. 80.81; p=0.042), more intense yolk color (14.38 vs. 8.70; p<0.01), and lower albumen pH (8.39 vs. 8.67; p=0.007). Feeding treatments and duration of egg storage did not significantly influence egg yolk lipid oxidation (p>0.05).
The integration of the ALICE trigger system with sub-detectors Krivda, M.; Barnby, L.; Bombara, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2010, Letnik:
617, Številka:
1
Journal Article
Recenzirano
The ALICE Trigger electronics (TRG) has been installed in the experimental cavern and tested with each of the detectors, both individually (‘standalone’ mode) and in ‘global’ runs, i.e. those ...involving other detectors. Global runs were performed with cosmic ray triggers, and also during the LHC startup period in September 2008. In this paper the status of the trigger system will be reviewed, in particular describing recent extensions to the system.
The ALICE trigger system installed in the experimental cavern processes information from triggering detectors at 3 hardware levels, and is used in p-p and Pb-Pb collisions. Many automatic functions ...have been developed to facilitate work in the control room. The hardware is permanently monitored, and around 1200 counters, with considerable built-in redundancy, are read at regular intervals (at least once per minute). This provides relevant physics information and also verifies the consistency of the hardware operation. In order to compensate for seasonal drift, the CORDE module has been installed, which allows the LHC clock to be delayed in steps of 10 ps. This paper describes the current status of the ALICE trigger system after experience with p-p and Pb-Pb runs, the new firmware developments and the appropriate software for this electronics.
The paper investigates the influence of dietary replacement of 3% sunflower oil (SO group) with 3% milk thistle oil (MTO group) in broiler diets on fattening characteristics and carcass quality. ...During 42 days of fattening, MTO group achieved insignificantly higher live weight(2.21 kg: 2.19 kg; P>0.05), significantly better feed conversion (1.80 kg: 1.83 kg; P = 0.034) and production number (292.33:285.33; P = 0.013) compared to the SO broiler group. Carcass weight and portion of main parts did not statistically significantly differ between the groups (P>0.05). Market value of carcass cuts and breast fillets was higher in MTO group than in SO group. Lipids of breast and thigh muscles in the SO group contained significantly higher concent.
In the ALICE experiment, the Low-Voltage Differential Signalling (LVDS) format is used for the transmission of trigger inputs from the detectors to the Central Trigger Processor (CTP), the L0 trigger ...outputs from Local Trigger Units (LTU) boards back to the detectors and the BUSY inputs from the sub-detectors to the CTP. ALICE has designed a set-up, called the LVDS transmission tester, that aims to measure various transmission quality parameters and the bit-error rate (BER) for long period runs in an automatic way. In this paper, this method is described and the conclusions from these tests for the ALICE LVDS cables are discussed.
Neonates and infants are susceptible to hypoxaemia in the perioperative period. The aim of this study was to analyse interventions related to anaesthesia tracheal intubations in this European cohort ...and identify their clinical consequences.
We performed a secondary analysis of tracheal intubations of the European multicentre observational trial (NEonate and Children audiT of Anaesthesia pRactice IN Europe NECTARINE) in neonates and small infants with difficult tracheal intubation. The primary endpoint was the incidence of difficult intubation and the related complications. The secondary endpoints were the risk factors for severe hypoxaemia attributed to difficult airway management, and 30 and 90 day outcomes.
Tracheal intubation was planned in 4683 procedures. Difficult tracheal intubation, defined as two failed attempts of direct laryngoscopy, occurred in 266 children (271 procedures) with an incidence (95% confidence interval CI) of 5.8% (95% CI, 5.1–6.5). Bradycardia occurred in 8% of the cases with difficult intubation, whereas a significant decrease in oxygen saturation (SpO2<90% for 60 s) was reported in 40%. No associated risk factors could be identified among co-morbidities, surgical, or anaesthesia management. Using propensity scoring to adjust for confounders, difficult anaesthesia tracheal intubation did not lead to an increase in 30 and 90 day morbidity or mortality.
The results of the present study demonstrate a high incidence of difficult tracheal intubation in children less than 60 weeks post-conceptual age commonly resulting in severe hypoxaemia. Reassuringly, the morbidity and mortality at 30 and 90 days was not increased by the occurrence of a difficult intubation event.
NCT02350348.
A measurement of strange baryon and antibaryon production in Pb–Pb collisions has been carried out by the NA57 experiment at the CERN SPS, with 40 and 158 AGeV/c beam momentum. Results on Λ, Ξ and Ω ...hyperon yields at mid-rapidity in the most central 53% of Pb–Pb collisions at 40 AGeV/c are presented and compared with those obtained at higher energy, in the same collision centrality range.
The Λ and Ξ− yields per unit rapidity stay roughly constant while those of Ω−, Λ̄, Ξ̄+ and Ω̄+ increase when going to the higher SPS energy. Hyperon yields at the SPS are compared with those from the STAR experiment in sNN=130 GeV Au–Au collisions at RHIC.
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