On the magnetic field evolution timescale in superconducting neutron star cores

We revisit the various approximations employed to study the long-term evolution of the magnetic field in neutron star cores and discuss their limitations and possible improvements. A recent controversy on the correct form of the induction equation and the relevant evolution timescale in superconducting neutron star cores is addressed and clarified. We show that this ambiguity in the estimation of timescales arises as a consequence of nominally large terms that appear in the induction equation, but which are, in fact, mostly irrotational. This subtlety leads to a discrepancy by many orders of magnitude when velocity fields are absent or ignored. Even when internal velocity fields are accounted for, only the solenoidal part of the electric field contributes to the induction equation, which can be substantially smaller than the irrotational part. We also argue that stationary velocity fields must be incorporated in the slow evolution of the magnetic field as the next level of approximation.Comment: 6 pages, version accepted by MNRA

Türkiye Cumhuriyeti ve halifelik

Taha Toros Arşivi, Dosya Adı: Son Halife Abdülmecit Efendi. Not: Gazetenin "Olaylar ve Görüşler" köşesinde yayımlanmıştır

Enterococcal periprosthetic joint infection: clinical and microbiological findings from an 8-year retrospective cohort study

BACKGROUND: Treatment of enterococcal periprosthetic joint infections (PJI) is challenging due to non-standardized management strategies and lack of biofilm-active antibiotics. The optimal surgical and antimicrobial therapy are unknown. Therefore, we evaluated characteristics and outcome of enterococcal PJI. METHODS: Consecutive patients with enterococcal PJI from two specialized orthopedic institutions were retrospectively analyzed. Both institutions are following the same diagnostic and treatment concepts. The probability of relapse-free survival was estimated using Kaplan-Meier survival curves and compared by log-rank test. Treatment success was defined by absence of relapse or persistence of PJI due to enterococci or death related to enterococcal PJI. Clinical success was defined by the infection-free status, no subsequent surgical intervention for persistent or perioperative infection after re-implantation and no PJI-related death within 3 months. RESULTS: Included were 75 enterococcal PJI episodes, involving 41 hip, 30 knee, 2 elbow and 2 shoulder prostheses. PJI occurred postoperatively in 61 episodes (81%), hematogenously in 13 (17%) and by contiguous spread in one. E. faecalis grew in 64 episodes, E. faecium in 10 and E. casseliflavus in one episode(s). Additional microorganism(s) were isolated in 38 patients (51%). Enterococci were susceptible to vancomycin in 73 of 75 isolates (97%), to daptomycin in all 75 isolates, and to fosfomycin in 21 of 22 isolates (96%). The outcome data was available for 66 patients (88%). The treatment success after 3 years was 83.7% (95% confidence interval [CI]; 76.1-96.7%) and the clinical success was 67.5% (95% CI; 57.3-80.8%). In 11 patients (17%), a new PJI episode caused by a different pathogen occurred. All failures occurred within 3 years after surgery. CONCLUSION: About half of enterococcal PJI were polymicrobial infections. The treatment success was high (84%). All treatment failures occurred within the first 3 years after revision surgery. Interestingly, 17% of patients experienced a new PJI caused by another pathogen at a later stage

Nanoscale Polymeric Particles via Aerosol-Photopolymerization

This PhD thesis focuses on the process of aerosol-photopolymerization for the generation of various polymeric particles. Such structures are most often prepared by liquid-based methods via the well-established thermal initiation step, and aerosol-photopolymerization is presented as an alternative, aerosol-based technique which employs photoinitiated polymerization. Discussed within this thesis are the advantages and broad aspects of the process

Perception of space through representation media: a comparison between 2D representation techniques and 3D virtual environments

Thesis (Master)--İzmir Institute of Technology, Architecture, İzmir, 2005Includes bibliographical references (leaves: 109-113)Text in English; Abstract: Turkish and Englishxii, 122 leavesFor centuries, 2D drawing techniques such as plans, sections and elevations have been the main communication media for the profession of architecture. Addition to these techniques, for two decades, computer based representation techniques and 3D virtual environments (VE) have also entered to the profession of architecture. Effects of these computer based techniques on perception of space have always been interrogated by several researches.Although these researches generally regarded these computerized techniques as better and proper than conventional techniques, in some cases conventional techniques can be more effective to depict architectural space. Main aim of this thesis is to compare and evaluate the positive effects and shortcomings of 3D virtual environments and 2D conventional representation techniques in the context of perception of architectural space. Parallel to this objective, the thesis also aims to show the differentiation in perception of space with the change of representation media. To show these differences, a comparative method is used. As the main step of the application of this method, an experimental case study and survey has been constituted for comparing 2D conventional techniques and 3D computer based techniques. In this survey, 38 first yearstudents from Izmir Institute of technology have taken place as test subject.According to the results of this comparative case study, contributions and shortcomings of 2D conventional representation techniques and 3D computer based techniques on improving the capability of architects on perception of the space have been determined

Remediation of the geotechnical problems of the Hasankeyf historical area, southeastern Turkey

The castle, palaces and man-made historical and recent cave dwellings of Hasankeyf will be partly flooded by the reservoir of the Ilisu dam which is planned to be constructed over the Tigris River. Hasankeyf is entirely within the Germik formation which is composed of whitish to light gray and/or beige, medium strong, fresh to slightly weathered, thick to very thick bedded, locally massive, almost horizontal or gently dipping silty, sandy limestone. The major geotechnical concerns in the area consist of the possibility of kinematic failure of the foundation of "Little Palace" and the collapse of some of the roofs of the adjacent man-made cave dwellings carved in rock due to insufficient pillar (wall) thicknesses to carry the overburden load. A limit equilibrium analysis of the kinematically unstable planar rock block underlying the foundation of 'Little Palace' was performed as a function of the water level in the reservoir. The maximum required anchor force was calculated as approximately 3,000 kN/m which led to a total anchor force of about 42,000 kN for the 14-m-wide slope face of the unstable planar block. The results of the finite element analysis to determine the minimum stable pillar (wall) thickness required between adjacent caves led to a recommendation to apply a steel arch support to one of the adjacent caves at Hasankeyf in case the wall thickness was less than or equal to 0.60 m

Analysis of risk factors leading to failure in septic two-stage exchange arthroplasty

The aim of this habilitation script was to arm the treating physicians with an armamentarium of knowledge to achieve better success in eradicating PJI. Therefore, the published data concentrated on identification of the factors leading to failure in two-stage exchange arthroplasty in patients with PJI and on optimization of infection-free survival. Microbial biofilm makes the diagnosis and the treatment of PJI more challenging and therefore biofilm-active antibiotics are crucial to enhance treatment success. Microorganisms, for which no biofilm active antibiotic exits, presents a major difficulty in achieving high infect eradication rates in these patients. According to the results of this habilitation script however, an individualization of antimicrobial and surgical therapy regimes with a longer prothesis-free interval and longer antibiotic administration may enable achieving similar success rates in patients irrespective of causative microorganism after two-stage exchange arthroplasty. Furthermore, the data presented in this habilitation script emphasizes the implementation of a treatment supported by a multidisciplinary team approach as a crucial step to optimize outcome in patients with PJI. It could have been shown, that high infection eradication rates can be achieved by using a standardized two-stage exchange arthroplasty supported by a multidisciplinary team even in a challenging patient cohort. Given the fact, that there is a wide variety in the definition of PJI and its treatment success, which causes a heterogeneity of existing studies, further research is highly needed on more precisely defining PJI and success. Thus, consistency in definition between studies will enhance the overall quality of existing literature. Especially, when defining treatment success, it is important to distinguish between a new infection and an ongoing infection, as this prevent patients from unnecessary surgical interventions and antimicrobial treatment