A transient liquid-like phase in the displacement cascades of zircon, hafnon and thorite

The study of radiation effects in solids is important for the development of 'radiation-resistant' materials for fission-reactor applications'. The effects of heavy-ion irradiation in the isostructural orthosilicates zircon (ZrSiO4), hafnon (HfSiO4) and thorite (ThSiO4) are particularly important because these minerals are under active investigation for use as a waste form for plutonium-239 resulting from the dismantling of nuclear weapons(2-4). During ion irradiation, localized 'cascades' of displaced atoms can form as a result of ballistic collisions in the target material, and the temperature inside these regions may for a short time exceed the bulk melting temperature. Whether these cascades do indeed generate a localized liquid state(5-8) has, however, remained unclear. Here we investigate the irradiation-induced decomposition of zircon and hafnon, and find evidence for formation of a liquidlike state in the displacement cascades. Our results explain the frequent occurrence of ZrO2 in natural amorphous zircong(9-12) Moreover, we conclude that zircon-based nuclear waste forms should be maintained within strict temperature Limits, to avoid potentially detrimental irradiation-induced amorphization or phase decomposition of the zircon.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62853/1/395056a0.pd

Jean-Baptiste Bélanger, hydraulic engineer, researcher and academic

Jean-Baptiste BÉLANGER (1790-1874) worked as a hydraulic engineer at the beginning of his career. He developed the backwater equation to calculate gradually-varied open channel flow properties for steady flow conditions. Later, as an academic at the leading French engineering schools (Ecole Centrale des Arts et Manufactures, Ecole des Ponts et Chaussées, and Ecole Polytechnique), he developed a new university curriculum in mechanics and several textbooks including a seminal text in hydraulic engineering. His influence on his contemporaries was considerable, and his name is written on the border of one of the four facades of the Eiffel Tower. BÉLANGER's leading role demonstrated the dynamism of practicing engineers at the time, and his contributions paved the way to many significant works in hydraulics

Professional development and sustainable development goals

Professional development is defined as a consciously designed systematic process that helps professionals to attain, utilize, and retain knowledge, skills, and expertise. It is simply a process of obtaining skills, qualifications, and experience that help in advancement in one’s career. In the field of education, it is defined as the process of improving staff skills and competencies needed to produce outstanding performance of students. It also refers to a process of improving an organization’s staff capabilities through access to education and training opportunities for better output. Professional development can include a variety of approaches such as formal and informal education, vocational, specialized, or skill-based training, or advanced professional learning

Tuberculous arthritis revisited as a forgotten cause of monoarticular arthritis

<b>Background and Objectives:</b> Tuberculosis (TB) continues to be a major concern for health care workers. The number of reported cases of extrapulmonary tuberculosis, particularly osteoarticular tuberculosis, is increasing. This fact is attributed to different factors such as underestimating the disease and difficulty in diagnosis, which requires tissue sampling and can lead to a delay in the diagnosis, and can result in significant morbidity and mortality. The aim of this study was to highlight the difficulties and delay in diagnosis of articular tuberculosis, raising the need to create awareness about the importance of early diagnosis to avoid major complications of joint destruction. <b>Design and Setting:</b> Retrospective review of patients presenting to a tertiary care center between 2003 and 2009. <b>Patients and Methods:</b> We reviewed cases who presented with monoarticular joint pain and swelling that failed to respond to treatment elsewhere and were eventually diagnosed as having articular tuberculosis. We collected the demographic data, history, data on clinical examination and the relevant laboratory investigations, in addition to the data on radiological studies. All patients were treated medically with antituberculosis chemotherapy and surgically according to the severity of joint destruction. <b>Results</b>: Thirteen patients had a mean age was 40 years (range, 17-70 years). The average delay in diagnosis was 2 years. Only 1 patient had pulmonary TB. The hip, knee and elbow were the most common joints involved. Bacteriology was positive in 69&#x0025; of the cases; and histopathology, in 92&#x0025;. Fifteen percent of the patients had arthrodesis. None showed recurrence after follow-up of 4 years. <b>Conclusion</b>: A high level of clinical suspicion is essential for early diagnosis and treatment of osteoarticular TB to reduce its significant morbidity