The cumulant ratios up to fourth order of the Z distributions of the largest fragment in spectator fragmentation following 107,124Sn+Sn and 124La+Sn collisions at 600 MeV/nucleon have been ...investigated. They are found to exhibit the signatures of a second-order phase transition established with cubic bond percolation and previously observed in the ALADIN experimental data for fragmentation of 197Au projectiles at similar energies. The deduced pseudocritical points are found to be only weakly dependent on the A/Z ratio of the fragmenting spectator source. The same holds for the corresponding chemical freeze-out temperatures of close to 6 MeV.
The experimental cumulant distributions are quantitatively reproduced with the Statistical Multifragmentation Model and parameters used to describe the experimental fragment multiplicities, isotope distributions and their correlations with impact-parameter related observables in these reactions. The characteristic coincidence of the zero transition of the skewness with the minimum of the kurtosis excess appears to be a generic property of statistical models and is found to coincide with the maximum of the heat capacity in the canonical thermodynamic fragmentation model.
The neutron emission in projectile fragmentation at relativistic energies was studied with the Large-Area-Neutron-Detector LAND coupled to the ALADIN forward spectrometer at the GSI ...Schwerionen-Synchrotron (SIS). Stable Sn124 and radioactive Sn107 and La124 beams with an incident energy of 600 MeV/nucleon were used to explore the N/Z dependence of the identified neutron source. A cluster-recognition algorithm is applied for identifying individual particles within the hit distributions registered with LAND. The obtained momentum distributions are extrapolated over the full phase space occupied by the neutrons from the projectile-spectator source. The mean multiplicities of spectator neutrons reach values of up to about 11 and depend strongly on the isotopic composition of the projectile. An effective source temperature of T≈2-5 MeV, monotonically increasing with decreasing impact parameter, is deduced from the transverse momentum distributions. For the interpretation of the data, calculations with the statistical multifragmentation model were performed. The variety of excited projectile spectators assumed to decay statistically is represented by an ensemble of excited sources with parameters determined previously from the fragment production observed in the same experiments. The obtained agreement is very satisfactory for more peripheral collisions where, according to the model, neutrons are mainly emitted during the secondary decays of excited fragments. The neutron multiplicity in more central collisions is underestimated, indicating that other sources besides the modeled statistical breakup contribute to the observed neutron yield. The choice made for the symmetry-term coefficient of the liquid-drop description of produced fragments has a weak effect on the predicted neutron multiplicities.
Sport is increasingly recommended for haemophilic patients due to physical and psychological benefits. ‘WATERCISE’ is a specific aqua‐training programme for haemophiliacs in which endurance, ...strength, coordination and mobility are trained. In the WAT‐QoL study benefits and risks of regular WATERCISE training sessions were investigated in terms of health‐related quality of life (HRQoL), physical functioning (PF), orthopaedic joint status (OJS), bleeding frequency and factor consumption. Patients in the WATERCISE group attended an aqua‐training programme once a week for 1 h over 12 months, patients in the control group did not. Patients were matched for clinical and demographic data. Information on clinical data, orthopaedic status, PF (HEP‐Test‐Q) and HRQoL were collected in both groups at baseline and at follow‐up (6 and 12 months). Twenty‐eight adult severely affected haemophilic patients (WATERCISE group: 10 haemophilia A (HA), 3 haemophilia B (HB) patients; control group: 12 HA and 3 HB patients) were enrolled (aged 40.68 ± 12.7 years). Baseline data (body mass indices, OJS, sportive activities, HRQoL and PF) were well distributed between groups. After 12 months the WATERCISE group reported a significantly better PF (MW = 65.22, SD = 11.3; MC = 52.5, SD = 15.0), especially for endurance (P < 0.004). Although always differently reported by the patients within the WATERCISE group, HRQoL did not prove to be significantly different between groups. WATERCISE seems to have a positive effect on the PF of patients suffering from haemophilia. These study findings need to be further investigated in a larger study group.
The A/Z dependence of projectile fragmentation at relativistic energies has been studied with the ALADIN forward spectrometer at SIS. A stable beam of (124)Sn and radioactive beams of (124)La and ...(107)Sn at 600 MeV per nucleon have been used in order to explore a wide range of isotopic compositions. Chemical freeze-out temperatures are found to be nearly invariant with respect to the A/Z of the produced spectator sources, consistent with predictions for expanded systems. Small Coulomb effects (DeltaT approximately 0.6 MeV) appear for residue production near the onset of multifragmentation.
The aim of this research was to study the ciliated protozoa community at three sampling stations that receive different levels of domestic sewage along the São Pedro Stream in the municipality of ...Juiz de Fora, Minas Gerais, Brazil, in order to determine the influence of organic pollution on this community and to assess the feasibility of using ciliates as water quality indicators. Four physical-chemical parameters of the water samples were evaluated: dissolved oxygen concentration, electrical conductivity, pH and temperature. The sediment was obtained manually, using dredges with capacity of 300 mL, at each collection point. Point 1 was located in a rural region that receives a low sewage load, while Points 2 and 3 were located in populated regions receiving high sewage loads. We found 22 ciliate species, of which 18 are included in the saprobic system and are considered bioindicators. These showed beta-mesosaprobic environments at Point 1 and alfa-mesosaprobic to polisaprobic environments at Points 2 and 3. The low levels of dissolved oxygen and the high electrical conductivity values at Points 2 and 3, together with the strong similarity between the ciliate taxocenoses of these points and the weak similarity between Point 1 and the other two, confirm the high sewage loads received at the latter two points. The combination of the biological indicators and physical-chemical analyses therefore proved itself to be an efficient method of evaluating water quality, and has excellent potential to support decisions on the conservation of headwaters and recuperation of degraded environments in lotic systems.
It is expected that the cross section for super-heavy nuclei production of Z > 118 is dropping into the region of tens of femto barns. This creates a serious limitation for the complete fusion ...technique that is used so far. Moreover, the available combinations of the neutron to proton ratio of stable projectiles and targets are quite limited and it can be difficult to reach the island of stability of super heavy elements using complete fusion reactions with stable projectiles. In this context, a new experimental investigation of mechanisms other than complete fusion of heavy nuclei and a novel experimental technique are invented for our search of super- and hyper-nuclei. This contribution is focused on that technique.
A simple method to reduce the background from secondary reactions in telescopes composed of long CsI(Tl) crystals is presented. The method has been developed for the KRATTA 1 modules.
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