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Background: Cervical Disc Arthroplasty (CDA) has beenconsidered as an alternative to cervical arthrodesis in thetreatment of Cervical Degenerative Disc Diseases (CDDD).Aim of Study: The aim of this study was to assess thelong-term clinical and radiographic outcomes of CDA.Patients and Methods: A total of 17 patients who under-went single-or two-level CDA with Prestige-LP Disc wereretrospectively investigated at a minimum of 4-year follow-up. Clinical assessments included Visual Analogue Scale (VAS) for neck and arm pain, Neck Disability Index (NDI),and Japanese Orthopedic Association (JOA) score. Radiologicalevaluations included Range of Motion (ROM) of the indexand adjacent levels, segmental angle, cervical sagittal align-ment, Heterotopic Ossification (HO) and Adjacent SegmentDegeneration (ASD).Results: Significant and maintained improvement in VASfor neck and arm, NDI and JOA were observed after a meanfollow-up of 54.7 months (p < 0.001). The preoperative ROMof the index level was 9.7o, which was maintained at 1-and2-year follow-up (9.3o, and 9.2o), but was decreased to 8.0oat final follow-up. Mobility was maintained in 84.2% (16/19)of the implanted prostheses at final follow-up. ROM of thesuperior and inferior adjacent segments, cervical sagittalalignment and cervical angel were all maintained. The inci-dence of HO was 36.8% at final follow-up, but it did notinfluence the clinical outcome. Radiographic ASD weredetected in 26.3% of the patients. However, the incidence ofsymptomatic ASD was only 5.2%.Conclusion: Cervical disc arthroplasty demonstrated amaintained and satisfactory clinical outcome at a minimal of4-year follow-up, with majority of the prostheses remainedmobile. Cervical disc arthroplasty can be considered as aneffective surgical method in treating CDDD.

Binnen het project ‘Samen werken aan Bèta Burgerschap’ is met leerkrachten uit het po en vo een aanpak ontwikkeld en geëvalueerd waarmee leerkrachten vorm kunnen geven aan burgerschapsonderwijs.Het projectbeoogt leerlingen toe te rusten met kennis zodat ze in staat zijn om hun eigen mening te vormen, deel te nemen aan discussies en samen met groepsgenoten na te denken over oplossingen voor actuele maatschappelijk-technologische vraagstukken. Hoe je kinderen daarbij leert te denken vanuit verschillende perspectieven, meningen te vormen, argumenten te formuleren, naar elkaars standpunt te luisteren en gezamenlijk tot een oplossing te komenwordt in dit webinar verder uitgelicht. Verder wordt er tijdens dit webinar ingegaan op de vragen: Wat zijn nu de effecten van een Bèta Burgerschapsaanpak? Welke rol spelen conflict en consensus in een democratie en wat betekent dat voor burgerschapsonderwijs in de klas?

Snow avalanches impose a considerable threat to infrastructure and human safety in snow bound mountain areas. Nevertheless, the spatial prediction of snow avalanches has received little research attention in many vulnerable parts of the world, particularly in developing countries. The present study investigates the applicability of a stand-alone convolutional neural network (CNN) model, as a deep-learning approach, along with two metaheuristic algorithms including grey wolf optimization (CNN-GWO) and imperialist competitive algorithm (CNN-ICA) in snow avalanche modeling in the Darvan watershed, Iran. The analysis was based on thirteen potential drivers of avalanche occurrence and an inventory map of previously documented avalanche occurrences. The efficiency of models’ performance was evaluated by Area Under the Receiver Operating Characteristic curve (AUC) and the Root Mean Square Error (RMSE). The CNN-ICA model yielded the highest accuracy in both training (AUC= 0.982, RMSE =0.067) and validation (AUC= 0.972, RMSE =0.125) steps, followed by the CNN-GWO model (AUC of 0.975 for training, RMSE of 0.18 for training, AUC of 0.968 for validation, RMSE of 0.157 for validation). However, the standalone CNN model showed lower goodness-of-fit (AUC= 0.864, RMSE =0.22) and predictive performance (AUC= 0.811, RMSE =0.330). The approach utilized in this study is broadly applicable for identifying areas where avalanche hazard is likely to be high and where mitigation measures or corresponding land use planning should be prioritized.

IntroductionKeratoconus (KC) is a developmental anomaly in which the inferior or central portion of the cornea becomes thinner and bulges forward in a cone-shaped fashion as a result of non-inflammatory thinning of the corneal stroma[1, 2]. The disease has its usual onset at puberty and, in many cases, progresses until the third to fourth decade of life, when it usually arrests[1]. Although a large proportion of keratoconic patients can be managed with contact lenses, an average of about 20% of all keratoconic corneas require keratoplasty; some authors report markedly different surgical indication rates of 6.5 and 12 to 45%.[3-5] Aim of the work: to study the prevalence of keratoconus in patients seeking refractive surgery to correct their refractive errors and to study common risk factors. Patients and Methods: Two thousand eyes to 1202 patients (623 males and 579 females) coming for investigations for refractive surgery were randomly chosen in the period from April to October 2015. Screening –by Pentacam- was bilateral in 798 patients and unilateral in 404 patients. Results: the resulting cases of keratoconus were 293 eyes (14.65%) of 210 patients. Of those patients, males were 117 (165 eyes) (56.25%) and females were 93 (128 eyes) (43.75%).

After a successful production of isotopes of element 116 in the reaction 48Ca + 248Cm, the reaction 54Cr + 248Cm → 302120* was investigated at the velocity filter SHIP at GSI, Darmstadt, aiming to search for isotopes of element 120. One chain of events was observed, which is not created by chance with high probability. Parts of the chain agree with model predictions and measured data from a decay chain which could start at the isotope 299120. In a complementary study, model dependent shell-correction energies and related heights of fission barriers were deduced from measured Qα values. The results are compared with predictions of macroscopic-microscopic models. The consequences for calculations of crosssections are discussed.

Fission fragment mass distributions were measured in heavy-ion induced fission of 238U. The mass distributions changed drastically with incident energy. The results are explained by a change of the ratio between fusion and quasifission with nuclear orientation. A calculation based on a fluctuation dissipation model reproduced the mass distributions and their incident energy dependence. Fusion probability was determined in the analysis. Evaporation residue cross sections were calculated with a statistical model for the reactions of 30Si+238U and 34S+238U using the obtained fusion probability in the entrance channel. The results agree with the measured cross sections of 263,264Sg and 267,268Hs, produced by 30Si+238U and 34S+238U, respectively. It is also suggested that sub-barrier energies can be used for heavy element synthesis.

The reaction 54Cr$ + $248Cm was investigated at the velocity filter SHIP at GSI, Darmstadt, with the intention to study production and decay properties of isotopes of element 120. Three correlated signals were measured, which occurred within a period of 279ms. The heights of the signals correspond with the expectations for a decay sequence starting with an isotope of element 120. However, a complete decay chain cannot be established, since a signal from the implantation of the evaporation residue cannot be identified unambiguously. Measured properties of the event chain are discussed in detail. The result is compared with theoretical predictions. Previously measured decay properties of even element super-heavy nuclei were compiled in order to find arguments for an assignment from the systematics of experimental data. In the course of this review, a few tentatively assigned data could be corrected. New interpretations are given for results which could not be assigned definitely in previous studies. The discussion revealed that the cross-section for production of element 120 could be high enough so that a successful experiment seems possible with presently available techniques. However, a continuation of the experiment at SHIP for a necessary confirmation of the results obtained in a relatively short irradiation of five weeks is not possible at GSI presently. Therefore, we decided to publish the results of the measurement and of the review as they exist now. In the summary and outlook section we also present concepts for the continuation of research in the field of super-heavy nuclei.

The isotope 261Sg and its decay product 257Rf were produced in the nuclear reaction 208Pb(54Cr, n)261Sg . The radioactive decay of these isotopes was investigated by means of $ \alpha$ , $ \alpha$ - $ \gamma$ and/or $ \alpha$ -X-ray spectroscopy. Improved spectroscopic data concerning $ \alpha$ energies, $ \gamma$ transitions, tentative spin and parity assignments of low-lying Nilsson single-neutron orbitals are presented for these nuclei.

In a series of experiments performed at the velocity filter SHIP, new or improved decay data of neutron-deficient isotopes of elements from mendelevium (Z = 101) to hassium (Z = 108) were obtained. In particular, evidence for $ \alpha$ -decay or electron capture from isomeric states in 265Hs and 258Db was found.

The radioactive decay of the isotopes 254-256Lr and their daughter products was investigated by means of α , prompt α -γ and delayed conversion electron-γ coincidence spectroscopy. The isotopes were produced using the reaction 48Ca + 209Bi .

A K isomer with a half-life of (110±10) ms at an excitation energy of 1254keV has been identified in the nucleus 252No . The isomer is interpreted as a two-quasineutron state with K π = 8- . The isotope 252No was produced in the fusion-evaporation reaction 206Pb(48Ca, 2n)252No . The experiment has been performed at the velocity filter SHIP of GSI Darmstadt.

An overview of present experimental investigation of superheavy elements is given. The data are compared with theoretical descriptions. Results are reported from an experiment to confirm production of element 112 isotopes in irradiation of 238 UF 4 with 48 Ca . One spontaneous fission event was measured, which agrees with three events of previously measured data which had been assigned to the decay of 283112. However, more experimental work is needed in order to obtain an independent and unambiguous confirmation of previous results.

Effects of the prolate deformation of 238 U on fusion were studied in the reaction 30 Si + 238 U at bombarding energies close to the Coulomb barrier. The fission (capture) cross sections were measured at the JAEA tandem accelerator to see the enhancement of the cross sections in the subbarrier energy due to the lower Coulomb barrier in the collisions of projectile at the polar sides of 238 U. In order to obtain the direct evidence for complete fusion, evaporation residue cross sections were measured at UNILAC of GSI. At the subbarrier energy of Ec.m. = 133.0 MeV, where only polar collisions to 238 U occur, we measured three spontaneously fissioning nuclei which we assigned to the isotope 264 Sg. The obtained cross section (10 +10 – 6 ) pb was smaller than the calculation that the system captured at the polar collisions results in complete fusion, suggesting the competition between fusion and quasifission. At the above barrier energy of Ec.m. = 144.0 MeV, where collisions on the equatorial side of 238 U start to contribute, we observed α-decay chains starting from 263 Sg and the cross section was determined to be (67 +67 ) pb. The data was reproduced by the calculation that the system captured from the equatorial side of 238 U results in complete fusion.

The decay of the isotopes 255Rf, 251No and 247Fm produced in the reactions $\mathrm{{}^{207}Pb\ensuremath({}^{50}Ti,2n){}^{255}Rf\ {}^{\alpha}_{\rightarrow}\ {}^{251}No\ \ensuremath{}^{\alpha}_{\rightarrow}\ {}^{247}Fm}$ , and $\mathrm{{}^{206}Pb\ensuremath({}^{48}Ca,3n){}^{251}No\ \ensuremath{}^{\alpha}_{\rightarrow}\ {}^{247}Fm}$ was investigated by means of α-γ spectroscopy. Previously observed γ transitions in coincidence with α decays of 255Rf were confirmed, their energies and line intensities were measured more precisely, and their multipolarities were determined as E1. In 251No a new isomeric state at E * > 1700keV with a half-life of ≈ 2μs was identified. The decay of 247Fm was measured more precisely. A partial level scheme of the daughter nucleus 243Cf could be established.

The reaction 30Si + 238U → 268Sg* was studied at beam energies close to the Coulomb barrier. At a center-of-mass energy of E c.m. = 144.0MeV for reactions at half thickness of the target we measured three decay chains of 263Sg produced by evaporation of five neutrons. The cross-section was ( 67+67 -37) pb. At E c.m. = 133.0MeV we measured three spontaneously fissioning nuclei which we assigned to the isotope 264Sg. The production cross-section was ( 10+10 -6) pb and a half-life of ( 120+126 -44) ms was determined. This half-life is a factor of twenty shorter than theoretical predictions. At E c.m. = 128.0MeV an upper cross-section limit of 15pb was measured. The cross-section data reveal a strong influence of the orientation of the deformed target nucleus on the production yield. Compared to excitation functions measured for the lighter system 16O + 238U → 254Fm*, a reduction of the fusion probability was observed at low beam energies indicating increasing competition from quasifission processes.

The decay of 255No was investigated by means of α-γ spectroscopy. The isotope was produced in the reactions 208Pb(48Ca, n)255No, \(\mathrm{{}^{209}Bi({}^{48}Ca,2n){}^{255}Lr \ {}^{\ensuremath \mathit{EC}}_{\rightarrow}\ {}^{255}No}\), and $238U(22Ne, 5n)255No$. Levels of the daughter nucleus 251Fm were assigned by α-γ coincidence measurements and on the basis of systematics. Level energies were determined precisely using measured γ-rays. The results are compared with the known level schemes of the lighter \(\ensuremath N=151\) isotones 247Cm and 249Cf as well as with data for 253No.

The 3/2- isomer in 185Pb and states above it have been populated in the α-decay of 189Po. The observed α-decay strengths to and the electromagnetic decay properties of the excited states in 185Pb have been combined with Potential Energy Surface and Particle-Plus-Rotor calculations to propose configuration assignments. It is suggested that the α-decaying isomer of 189Po is of prolate origin and that the prolate configuration becomes very low in energy in 185Pb.

The upgraded separator VASSILISSA was used to confirm results of previous experiments on the synthesis of the heavy isotopes of the element 112 obtained in complete-fusion reactions of 48Ca and 238U. An additional reason was the non-observation of any events in the same reaction studied with the BGS separator at Berkeley. Limits of $280 \leq A \leq 286$ for the atomic mass number of the observed spontaneously fissioning isotope were measured. The obtained results on the decay mode, half-life and production cross-section are in agreement with those obtained in our first experiment.

Detailed fine-structure $\alpha$ -decay studies of 188,190Bi were performed using the complete-fusion reactions of 50,52Cr ions with a 142Nd target at the velocity filter SHIP. The evaporation residues were separated in-flight and subsequently identified on the basis of recoil- $\alpha$ , recoil- $\alpha$ - $\gamma$ /X-ray and excitation function measurements. Improved data on the $\alpha$ -decay of 188,190Bi were obtained and a number of new low-lying excited states in the daughters 184,186Tl were observed. An intruder, presumably 10- state was identified in 184Tl, extending the systematics of such states in the odd-odd Tl nuclei beyond the neutron mid-shell at N = 104. Some technical aspects of experiment at recoil separators are also discussed.

Within the past twelve years, the recoil separator VASSILISSA has been used for the investigations of evaporation residues produced in heavy-ion-induced complete fusion reactions. In the course of the experimental work, fourteen new isotopes have been identified by the parent-daughter correlations in the region of elements with 92≤Z≤94. The study of the decay properties and formation cross sections of the isotopes of elements 110, 112, and 114 was performed using high-intensity 48Ca beams and 232Th, 238U, and 242Pu targets. At the beam energies corresponding to the calculated cross-section maxima of the 3n evaporation channels, the isotopes 277110, 283112, and 287114 were produced and identified. For further experiments aimed at the synthesis of the superheavy element isotopes (Z≥110) with the use of intensive 48Ca extracted beams, improvements in the ion optical system of the separator and the focal plane detector system have been made.

Heavy-ion fusion reactions 48Ca + 204Pb and 44Ca + 208Pb leading to the same compound nucleus 252No* were run in attempts to produce new neutron-deficient spontaneous-fission isotopes of 249,250No using the electrostatic separator VASSILISSA. Production cross-sections for the spontaneous-fission activities with the half-lives 5.6 and 54 μs observed in these reactions are compared with the measured ones for the well-known isotopes of 251 - 255No formed in the heavy-ion fusion reactions 48Ca + 206Pb and 48Ca + 208Pb. The obtained excitation functions for the reaction products formed after the evaporation of 1-4 neutrons from the corresponding compound No nuclei have been compared with similar data obtained earlier and results of statistical model calculations.

Purpose The purpose of this study was to evaluate the prevalence of keratoconus among candidates of refractive surgery in Upper Egypt. Setting The study was conducted in Sohag University Hospital and Future Center (a private center) for laser in-situ keratomiluesis and refractive surgery in Sohag Governorate, Egypt. Design This is an observational cross-sectional study. Patients and methods Refractive surgery candidates referred for preoperative evaluation before laser in-situ keratomiluesis, photorefractive keratectomy, and phakic intraocular lens implantation in the period from April 2015 to September 2015 were screened for keratoconus using Sirrus Scheimpflug camera. Results The study included 1202 patients, 623 male and 579 female. Keratoconus was detected in 210 (17.5%) patients. Conclusion Prevalence of keratoconus among refractive surgery candidates in Upper Egypt is relatively high, which may reflect an underlying high prevalence in the general population.

The radioactive decay of 217Pa was investigated by means of α-γ-spectroscopy. Fine structure in the ground-state α-decay was established. Ambiguities in the fine structure of the α-decay of the previously known isomeric state could be clarified by α-γ-coincidence measurements. A previously unknown α-transition of Eα = (8306 ± 5) keV was detected and identified by means of delayed α-α- and α-γ-γ-coincidence measurements. A second isomeric state decaying by α-emission was not observed. The quality of the previously reported data of the α-decay fine structure of 217Th was improved.

Cerebral vasculopathy exposes patients to a high risk of stroke, a major complication of sickle cell disease (SCD) associated with a high risk of death and disability. Transcranial doppler (TCD) ultrasonography used to identify SCD patients at risk of stroke may contribute to significantly reducing morbidity and mortality in these patients by indicating appropriate treatment. From March 2008 to February 2013, we conducted systematic screening for cerebral vasculopathy using TCD in 572 SCD patients (including 375 SS, 144 SC, 26 S/β(0), and 27 S/β(+) thalassemia patients) aged 1-17 years in a comprehensive center for follow-up and research on sickle cell disease in Bamako, Mali. After exclusion of 30 inadequate results and one case of abnormal TCD observed in a multiple organ failure patient, we found an abnormal or conditional TCD in 18% of 541 children examined in a steady state. The highest prevalence of abnormal cases concerned homozygous SS patients (8.1%). No case of abnormal or conditional TCD was observed in children with S/β(+) thalassemia. Hemoglobin concentrations were significantly lower in patients with conditional or abnormal TCD (P0.01). In a subgroup of 68 patients with conditional TCD, nine (13%) converted to abnormal TCD over 1 year. In this subgroup of 68 conditional TCD patients, a decrease or increase in baseline hemoglobin concentration was predictive of conditional or abnormal TCD at the follow-up visit. Progression towards conditional TCD was observed in four patients (0.9%) who initially had normal TCD. Children with abnormal TCD had, whenever possible, a monthly exchange transfusion program. One case of transient stroke in the context of P. falciparum malaria with low hemoglobin concentration and one death were observed. These findings highlight the need for systematic TCD in sickle cell disease monitoring and implementing regular blood transfusion programs in the context of limited access to regular and secure blood transfusions.

New microsecond isomers in the neutron-deficient isotopes 189g, 190Bi have been identified after in-flight separation by the velocity filter SHIP. The evaporation residues were identified on the basis of delayed recoil-γ/X-ray, recoil-γ/X-ray-α and excitation function measurements. The systematics of the [ π1i 13/2]13/2+ excited states in the odd-mass Bi nuclei is discussed.

The even-even nucleus 270110 was synthesized using the reaction 64Ni + 207Pb. A total of eight α-decay chains was measured during an irradiation time of seven days. Decay data were obtained for the ground-state and a high-spin K isomer. The new nuclei 266Hs and 262Sg were identified as daughter products after α-decay. Spontaneous fission of 262Sg terminates the decay chain. The measured data are in agreement with calculations using the macroscopic-microscopic model and with self-consistent HFB calculations with Skyrme-Sly4 interaction.

Two excited J(pi)=0(+) states in Pb-186 populated in the a-decay of Po-190 have been identified through alpha -particle/conversion electron coincidences in an experiment at the velocity filter SHIP ...

Objective To investigate a new method of quantification of the diastolic notch of the flow velocity waveforms of uterine arteries in the prediction of hypertensive disorders of pregnancy. Methods Pulsed-wave Doppler was used to obtain flow velocity waveforms (FVWs) from the uterine arteries at 21-22 weeks of gestation from 531 nulliparous women and 94 multiparous women at high risk. From the FVWs, both the pulsatility index (PI) and the notch index (NI) were calculated and the predictive values for both indices were compared using logistic regression analysis for mild and severe early onset hypertensive pregnancy complications. Results Both the PI and the NI were poor predictors for mild gestational hypertension and pre-eclampsia; predictive values for severe early onset disease, however, were much better Logistic regression analysis showed the NI has no additional value compared with the Pf in the prediction of either mild or severe disease. Conclusions The NI offers the possibility to quantify the diastolic notch in uterine artery analysis. Compared to the PI, this does not lead to better predictive values for hypertensive disorders of pregnancy.

Neutron deficient isotopes of elements Z = 86–92 have been produced by heavy-ion fusion reactions 12C + 208Pb, 209Bi, 22Ne + 208Pb, 51V + 170Er, and 50Ti + 170Er. The evaporation residues were investigated by means of α- and α-γ-spectroscopy after in-flight separation from the projectile beam by the velocity filter SHIP and implantation into a 16-strip position-sensitive Si-detector. New or improved decay data for 225,226U, 216,217m,218Pa, 215,216,217Th, 214,215,216,216mAc, 214Ra and 213Rn have been obtained.

New neutron-deficient isotopes 188,189Po have been produced in the complete fusion reaction of 52Cr ions with a 142Nd target at the velocity filter SHIP. The evaporation residues were separated in-flight and subsequently identified on the basis of α-γ and α-conversion electron coincidence measurements and of α-α position and time correlations. In 189Po a ground state to ground state α decay with Eα1= 7540(20) keV, T1/2= 5(1) ms and two fine structure α-decays at Eα2= 7264(15) keV and Eα3= 7316(15) keV have been observed. In 188Po (T1/2= 400+200 −150μs) a ground state to ground state α decay at Eα= 7915(25) keV and a fine structure α decay at Eα= 7350(40) keV have been found. Improved data on the α-decay of 189Bi were obtained.

The stability of heavy nuclides, which tend to decay by α-emission and spontaneous fission, is determined by the structural properties of nuclear matter. Nuclear binding energies and lifetimes increase markedly in the vicinity of closed shells of neutrons or protons (nucleons), corresponding to ‘magic’ numbers of nucleons; these give rise to the most stable (spherical) nuclear shapes in the ground state. For example, with a proton number of Z = 82 and a neutron number of N = 126, the nucleus 208Pb is ‘doubly-magic’ and also exceptionally stable. The next closed neutron shell is expected at N = 184, leading to the prediction of an ‘island of stability’ of superheavy nuclei, for a broad range of isotopes with Z = 104 to 120 (refs 1, 2). The heaviest known nuclei have lifetimes of less than a millisecond, but nuclei near the top of the island of stability are predicted to exist for many years. (In contrast, nuclear matter consisting of about 300 nucleons with no shell structure would undergo fission within about 10−20 seconds.) Calculations3,4,5 indicate that nuclei with N > 168 should already benefit from the stabilizing influence of the closed shell at N = 184. Here we report the synthesis of an isotope containing 114 protons and 173 neutrons, through fusion of intense beams of 48Ca ions with 242Pu targets. The isotope decays by α-emission with a half-life of about five seconds, providing experimental confirmation of the island of stability.

The reaction 48Ca+238U was investigated at the recoil separator VASSILISSA at the Flerov Laboratory of Nuclear Reactions, JINR Dubna, in attempts to synthesize new isotopes of element 112. The experiments were performed at two beam energies resulting in excitation energies of the compound nucleus of 33 and 39 MeV. The collected beam dose was 3.5 × 1018 and 2.2 × 1018, respectively. Two spontaneous fission events were observed at the lower beam energy, which tentatively were assigned to the new neutron rich isotope 283112 produced in the reaction 238U(48Ca,3n)283112. The measured cross-section is (5.0+6.3−3.2) pb and the half–life is (81+147−32) s. No event was observed at the higher beam energy resulting in the upper cross–section limit of 7.3 pb.

Spontaneous fission and α-decay of253−257104 and 258106 were investigated in irradiations of 204,206,208Pb with 50Ti and 209Bi with 51V, respectively. New spontaneous fission activities were identified and assigned to 253104, 254104, and 258106. The half-lives were measured as T1/2 = (48 −10 +14 ) μs for 253104, T1/2 = (23 ± 3) μs for 254104, and T1/2 = (2.9 −0.7 +1.3 ) ms for 258106. No indication for α-decay of any of these isotopes was found. For the α-decay branching ratios bα limits corresponding to bα ≤ 0.1 for 253104, bα ≤ 0.015 for 254104, and bα ≤0.2 for 258106 were obtained. These results prove a reduced fission probability for nuclei with neutron numbers N=152 up to Z=106 and a steep decrease of the fission half-lives for neutron numbers N < 152 up to element 104. α-decay data of 257104 and 255104 have been improved. An isomeric state decaying by α-emission was identified in 257104 and attributed to a low lying 11/2- [725] state. A small α-decay branch for the even — even nucleus 256104, indicated in an earlier experiment at SHIP, was confirmed, allowing a better founded extrapolation of experimental masses for even — even nuclei up to 264Hs (Z=108), the heaviest even — even nucleus identified so far.

The production cross sections were measured for the xn, pxn, and αxn de-excitation channels of the 212Rn compound nuclei formed at excitation energies of 80–160 MeV in the reaction 22Ne + 190Os. The maximum cross sections obtained for the xn (x = 8–12), pxn (x = 8–11) and αxn (x = 8–11) reaction channels were fitted satisfactorily with the computer code HIVAP using its standard parameter set except that the single scaling parameter C = 0.65 was implemented to adjust the values of the liquid-drop fission barriers predicted by the Cohen-Plasil-Swiatecki (CPS) model. Additionally, an analysis of a large set of data on the formation cross sections of neutron-deficient Z = 83–92 nuclei showed that the whole body of data obtained for the nuclear region notable for the large variations of both the liquid-drop barrier and the shell effects, can be described well with practically the same parameter C = 0.55–0.68. One may take this observation as an indication that, though the CPS model overestimates the liquid-drop fission barriers, it reproduces well the relative behaviour of these barriers in the whole range of neutron-deficient Z = 83–92 nuclei.

In recent experiments at the velocity filter Separator for Heavy Ion reaction Products (SHIP) (GSI, Darmstadt), an extended and improved set of $\ensuremath{\alpha}$-decay data for more than 20 of the most neutron-deficient isotopes in the region from lead to thorium was obtained. The combined analysis of this newly available $\ensuremath{\alpha}$-decay data, of which the $^{186}\mathrm{Po}$ decay is reported here, allowed us for the first time to clearly show that crossing the $Z=82$ shell to higher proton numbers strongly accelerates the $\ensuremath{\alpha}$ decay. From the experimental data, the $\ensuremath{\alpha}$-particle formation probabilities are deduced following the Universal Decay Law approach. The formation probabilities are discussed in the framework of the pairing force acting among the protons and the neutrons forming the $\ensuremath{\alpha}$ particle. A striking resemblance between the phenomenological pairing gap deduced from experimental binding energies and the formation probabilities is noted. These findings support the conjecture that both the $N=126$ and $Z=82$ shell closures strongly influence the $\ensuremath{\alpha}$-formation probability.

Detailed $\ensuremath{\alpha}$-decay studies of ${}^{179}$Tl${}^{g}$ and its daughter products ${}^{175}$Au${}^{g}$ and ${}^{171}$Ir${}^{g}$ were carried out in two complementary experiments at the mass separator ISOLDE (CERN) and velocity filter SHIP (GSI). First unambiguous determination of the $\ensuremath{\alpha}$-decay properties of ${}^{175}$Au${}^{g}$ was performed as follows: ${E}_{\ensuremath{\alpha}}$ $=$ 6433(4) keV, ${T}_{1/2}$ $=$ 207(7) ms, and $\ensuremath{\alpha}$-decay branching ratio 90(7)$%$. First determination of the $\ensuremath{\alpha}$-decay branching ratios for ${}^{179}$Tl${}^{g}$ and ${}^{171}$Ir${}^{g}$ was also made: ${b}_{\ensuremath{\alpha}}$(${}^{179}$Tl${}^{g}$) $=$ 60(2)$%$ and ${b}_{\ensuremath{\alpha}}$(${}^{171}$Ir${}^{g}$) $=$ 15(2)$%$. The spins of the ground states in ${}^{175}$Au and ${}^{171}$Ir are established as 1/2${}^{+}$.

Decay properties of the very neutron-deficient isotopes ${}^{197\char21{}199}$Fr were studied at the velocity filter Separator for Heavy Ion reaction Products (SHIP) at GSI in Darmstadt. The isotopes were produced in the $2n\char21{}4n$ evaporation channels of the fusion-evaporation reaction ${}^{60}$Ni+${}^{141}$Pr $\ensuremath{\rightarrow}$ ${}^{201}$Fr*. Improved $\ensuremath{\alpha}$-decay properties of ${}^{199}$Fr were determined and the possible existence of two $\ensuremath{\alpha}$-decaying states in this nucleus is discussed. For the isotope ${}^{198}$Fr a broad $\ensuremath{\alpha}$-decay energy distribution was detected in the range of $(7470\char21{}7930)$ keV and two $\ensuremath{\alpha}$-decaying states were observed with half-lives of 1.1(7) and 15(3) ms. The new isotope ${}^{197}$Fr was identified based on the observation of one $\ensuremath{\alpha}$-decay chain yielding ${E}_{\ensuremath{\alpha}}=7728(15)$ keV and ${T}_{1/2}=0.{6}_{\ensuremath{-}0.3}^{+3.0}$ ms. The systematics of reduced $\ensuremath{\alpha}$-decay widths are presented for neutron-deficient francium, radon, and astatine isotopes.

Velocity distributions and production cross sections of evaporation residues have been measured in the reaction20Ne+208Pb at projectile energies of 8.6, 11.4, 14.9 A.MeV. Essential deviations from statistical model of deexcitation have been observed. Monte Carlo simulations involving emission of non-equilibrium particles have been used in order to reproduce experimental velocity, charge and mass distributions of evaporation residues and to estimate indirectly multiplicities of pre-equilibrium particles.

A possibility of using the Cherenkov technique to measure the average energy of collimated relativistic nuclear 79Au beams is investigated in the article for specific beam—radiator interaction (strong deceleration, fragmentation) produces a considerable effect of the spreading of the Cherenkov one. Two Cherenkov methods — achromatic (E, α) and combined (“combi”) — were employed for this purpose. At an energy about 1 GeV/u the accuracy of measurement by the “combi” method was ± 1.4 MeV/u. The accuracy of measurement by the (E, α) method was ±0.9 MeV/u at the energy EAu≈640 MeV/u. These results turned out to be in good agreement with initial EAu0 data from the SIS accelerator with allowances made for energy losses over the beam line (the maximum discrepancy was ≤0.4%). With all the set of these data, the direction condition was for the first time checked for VChR from heavy nuclei. It is shown to be fulfilled to an accuracy above ±5′ in the angle range 27°

By using the recoil-fission correlation technique, the exotic process of beta-delayed fission ($\ensuremath{\beta}$DF) was unambiguously identified in the very neutron-deficient nuclei ${}^{192,194}$At in experiments at the velocity filter SHIP at Gesellschaft f\"ur Schwerionenforschung (GSI). The upper limits for the total kinetic energy release in fission of ${}^{192,194}$Po, being the daughter products of ${}^{192,194}$At after ${\ensuremath{\beta}}^{+}/EC$ decay, were estimated. The possibility of an unusually high $\ensuremath{\beta}$DF probability for ${}^{192}$At is discussed.

By using the technique of correlating implanted evaporation residues and their subsequent fission decay, $\ensuremath{\beta}$-delayed fission ($\ensuremath{\beta}$DF) of ${}^{186}$Bi has been identified for the first time and $\ensuremath{\beta}$DF of ${}^{188}$Bi has been unambiguously confirmed. The experiments were performed at the velocity filter SHIP (GSI, Darmstadt). The $\ensuremath{\beta}$DF probabilities for both nuclides were qualitatively estimated, and, in particular indications for a large value in the case of ${}^{186}$Bi are regarded.

Fission fragment mass distributions were measured in the heavy-ion induced fission using 238U target nucleus. The mass distributions changed drastically with incident energy. The results are explained by a change of the ratio between fusion and qasifission with nuclear orientation. A calculation based on a fluctuation dissipation model reproduced the mass distributions and their incident energy dependence. Fusion probability was determined in the analysis. Evaporation residue cross sections were calculated with a statistical model in the reactions of 30Si+238U and 34S+238U using the obtained fusion probability in the entrance channel. The results agree with the measured cross sections of 263,264Sg and 267,268Hs, produced by 30Si+238U and 34S+238U, respectively. It is also suggested that the sub-barrier energies can be used for heavy element synthesis.