Nuclear pairing and Coriolis effects in proton emitters

We introduce a Hartree-Fock-Bogoliubov mean-field approach to treat the problem of proton emission from a deformed nucleus. By substituting a rigid rotor in a particle-rotor-model with a mean-field we obtain a better description of experimental data in $^{141}$Ho. The approach also elucidates the softening of kinematic coupling between particle and collective rotation, the Coriolis attenuation problem.Comment: 2 pages, 1 figur

Nasopharyngeal temperature probes: is South Africa’s current decontamination process adequate?

Background: The standard practice in many institutions incorporates nasopharyngeal probes for temperature monitoring in patients undergoing general anaesthesia. Current disinfection guidelines for these devices are not clear and they are poorly adhered to. In South Africa, these temperature probes are reused and subjected to unstandardized decontamination processes. This study sought to investigate nasopharyngeal temperature probes as possible source for cross-contamination, and assess the efficacy of current disinfection practices for these probes. Methodology: This was an analytical double-blind randomized study of 4 different disinfection protocols for 48 nasopharyngeal temperature probes. The probes were randomized to disinfection protocols that included water wash, dry wipe, hibitane® and cidex® wash. After decontamination by the respective protocol, the probes were aseptically placed in nutrient broths, manually agitated and removed, and the broths were then inoculated onto blood agar plates. After 48 hours of aerobic culture incubation at 37oC, plates were examined for growth and bacteria identified using automated bioMérieux Vitek-2 microbial identification system. Chi square and logistic regression analyses were used to assess bacterial contamination rates of the disinfected probes, in order to infer the efficacy of the decontamination processes. Results: Of the 48 nasopharyngeal temperature probes disinfected by the different protocols, 22 (45.8%) had bacterial contamination, with frequency of isolation for coagulase negative staphylococci (44%), Bacillus cereus (20%), Staphylococcus aureus (10%), Enterobacter cloaca (7%), Pseudomonas aeruginosa (4%), Pseudomonas fluorescens (3%), Acinetobacter baumannii (3%), amongst other bacterial species. Dry wipe, and water and soap methods, had statistically significant higher contamination rates of 83.3% and 66.7% than hibitane® and cidex®, with 25.0% and 8.3% respectively (X2=17.69, p<0.0001). The odds of contamination when water-wipe was used as a cleaning method was 6 times (OR=6.000; 95% CI=1.018-35.374, p=0.048) that of hibitane® method while the odds for dry-wipe was 15 times (OR=15.000, 95% CI=2.024-111.174, p=0.008). No statistically significant difference was observed in the contamination rates between cidex® and hibitane® disinfection methods(OR=0.273, 95% CI=0.024-3.093, p=0.294). Conclusion: These data shows that nasopharyngeal temperature probes are possible source of crosscontamination and pathogen transmission due to inadequacy of the decontamination processes for these temperature probes

Hindrance of Heavy-ion Fusion at Extreme Sub-Barrier Energies in Open-shell Colliding Systems

The excitation function for the fusion-evaporation reaction 64Ni+100Mo has been measured down to a cross-section of ~5 nb. Extensive coupled-channels calculations have been performed, which cannot reproduce the steep fall-off of the excitation function at extreme sub-barrier energies. Thus, this system exhibits a hindrance for fusion, a phenomenon that has been discovered only recently. In the S-factor representation introduced to quantify the hindrance, a maximum is observed at E_s=120.6 MeV, which corresponds to 90% of the reference energy E_s^ref, a value expected from systematics of closed-shell systems. A systematic analysis of Ni-induced fusion reactions leading to compound nuclei with mass A=100-200 is presented in order to explore a possible dependence of the fusion hindrance on nuclear structure.Comment: 10 pages, 9 figures, Submitted to Phys. Rev.

The Go Clean Cup

Single-serve coffee machines and pods have gained popularity in recent years for ease of use. While these machines can save energy and water in the long run, especially in business settings, the consequences include billions of disposable coffee pods being thrown into landfills around the world each year. Although companies, such as Keurig®, have made reusable pods to fix this problem, the current designs are incompatible with many machines and they use hard plastic, making them difficult to clean. According to a survey conducted by the Go Clean Cup project, 63% of consumers would buy a new reusable single-serve coffee pod of equal price as the others if it was easier to clean. The Go Clean Cup is a reusable single-serve coffee pod that is flexible and eversible for easy cleaning. The pod can be partially or completely everted for coffee grounds to be wiped out without hassle and will be universally compatible with single-serve beverage machines. With a pending utility patent on the design, the Go Clean Cup project is currently focused on developing the best manufacturing method, including molding and laser drilling, to get the product on retail shelves for the lowest cost

Calibration of Pulse-Shape Discriminating NaI(Tl) Detectors

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

Decay Rate of Triaxially-Deformed Proton Emitters

The decay rate of a triaxially-deformed proton emitter is calculated in a particle-rotor model, which is based on a deformed Woods-Saxon potential and includes a deformed spin-orbit interaction. The wave function of the $I=7/2^{-}$ ground state of the deformed proton emitter $^{141}$Ho is obtained in the adiabatic limit, and a Green's function technique is used to calculate the decay rate and branching ratio to the first excited 2$^{+}$ state of the daughter nucleus. Only for values of the triaxial angle $\gamma$ $<5^{\circ}$ is good agreement obtained for both the total decay rate and the 2$^{+}$ branching ratio.Comment: 19 pages, 4 figure

South African Renal Registry Annual Report 2015

The fourth annual report of the South African Renal Registry summarises the 2015 data on renal replacement therapy (RRT) for patients with end-stage renal disease (ESRD) in South Africa. The South African population increased to 54.96 million in 2015, from 54.00 million in 2014. In December 2015, the number of patients with ESRD who were treated with chronic dialysis or transplantation stood at 10 360, a prevalence of 189 per million population (pmp). The prevalence was 167 pmp in 2013 and 178 pmp in 2014. The increasing prevalence observed is due mainly to the increased numbers of patients accessing haemodialysis in the private sector. In the public sector, which serves 84% of the South African population, the prevalence of RRT (71.9 pmp in 2015) remains at levels close to those reported in 1994 so that the disparity in access continues to increase. The disparities between provinces remain, with Limpopo and Mpumalanga the most under-served, as do the disparities between ethnic groups, with Blacks being the most under-served group