110 research outputs found
Surface Instabilities on Liquid Oxygen in an Inhomogeneous Magnetic Field
Liquid oxygen exhibits surface instabilities when subjected to a sufficiently
strong magnetic field. A vertically oriented magnetic field gradient both
increases the magnetic field value at which the pattern forms and shrinks the
length scale of the surface patterning. We show that these effects of the field
gradient may be described in terms of an ``effective gravity'', which in our
experiments may be varied from 1g to 360g.Comment: 4 pages, 5 embedded figures in eps forma
Effects of thermal shocks on the release of radioisotopes and on molten metal target vessels
The ISOLDE pulsed proton beam peak power amounts to 500 MW during the 2.4 ms proton pulse. The fraction of the proton pulse energy deposited in the target material is at the origin of severe thermal shocks. Quantitative measurement of their effect on the release of radioelements from ISOLDE targets was obtained by comparison of release profiles measured under different proton beam settings. The thermal shock induced in liquids (Pb, Sn, La) lead to mechanical failure of ISOLDE molten metal target vessels. Failure analysis is presented and discussed in the light of the response of mercury samples submitted to the ISOLDE beam and monitored by high-speed optical systems
The evolution of the ISOLDE control system
The ISOLDE on-line mass separator facility is operating on a Personal Computer based control system since spring 1992. Front End Computers accessing the hardware are controlled from consoles running Microsoft WindowsTM through a Novell NetWare4TM local area network. The control system is transparently integrated in the CERN wide office network and makes heavy use of the CERN standard office application programs to control and to document the running of the ISOLDE isotope separators. This paper recalls the architecture of the control system, shows its recent developments and gives some examples of its graphical user interface
公众参与消防安全建设:路径选择与制度供给
消防安全是公共安全的重要组成部分,公众参与消防安全建设是消防安全管理工作的内在需求和必然趋势。积极探索公众参与消防安全建设的具体路径,为公民参与消防建设提供制度保障是当前消防管理工作的重要课题。本文力图从消防政策的制定与监督、社会化的消防工作网络、依托社会的消防教育三个方面构建以政府为主导的公民参与消防安全建设的路径,并为这些参与途径设计了以信息公开及法制建设为基础,以增强民间组织参与能力为目标,以经济、文化等各种手段为支持的公众参与消防建设的制度框架
Production yields of noble-gas isotopes from ISOLDE UC/graphite targets
Yields of He, Ne, Ar, Kr and Xe isotopic chains were measured from UC/graphite and ThC/graphite targets at the PSB-ISOLDE facility at CERN using isobaric selectivity achieved by the combination of a plasma-discharge ion source with a water-cooled transfer line. %The measured half-lives allowed %to calculate the decay losses of neutron-rich isotopes in the %target and ion-source system, and thus to obtain information on the in-target %productions from the measured yields. The delay times measured for a UC/graphite target allow for an extrapolation to the expected yields of very neutron-rich noble gas isotopes, in particular for the ``NuPECC reference elements'' Ar and Kr, at the next-generation radioactive ion-beam facility EURISOL. \end{abstract} \begin{keyword} % keywords here, in the form: keyword \sep keyword radioactive ion beams \sep release \sep ion yields \sep ISOL (Isotope Separation On-Line) \sep uranium and thorium carbide targets. % PACS codes here, in the form: \PACS code \sep code \PACS 25.85.Ge \sep 28.60+S \sep 29.25.Rm
Oxide Fiber Targets at ISOLDE
Many elements are rapidly released from oxide matrices. Some oxide powder targets show a fast sintering, thus losing their favorable release characteristics. Loosely packed oxyde fiber targets are less critical since they may maintain their open structure even when starting to fuse together at some contact points. The experience with various oxyde fiber targets (titania, zirconia, ceria and thoria) used in the last years at ISOLDE is reviewed. For short-lived isotopes of Cu, Ga and Xe the zirconia and ceria targets respectively provided significantly higher yields than any other target (metal foils, oxide powders, etc.) tested before. Titania fibers, which were not commercially available, were produced in a relic process by impregnation of a rayon felt in a titanium chloride solution and subsequent calcination by heating the dried felt in air. Thoria fibers were obtained either by the same process or by burning commercial gas lantern mantle cloth. In the future a beryllia fiber target could be used to produce very intense ^6He beams (order of 10^13 ions per s) via the ^9Be(n, alpha) reaction using spallation neutrons
On-line yields obtained with the ISOLDE RILIS
The ISOLDE resonance ionization laser ion source (RILIS) allows to ionize efficiently and selectively many metallic elements. In recent yield surveys and on-line experiments with the ISOLDE RILIS we observed Mg , Al , Cd , Tb , Yb , Tl , Pb and Bi. The obtained yields are presented together with measured release parameters which allow to extrapolate the release efficiency towards more exotic (short-lived) nuclides of the same elements
Emerging Synergisms Between Drugs and Physiologically-Patterned Weak Magnetic Fields: Implications for Neuropharmacology and the Human Population in the Twenty-First Century
Synergisms between pharmacological agents and endogenous neurotransmitters are familiar and frequent. The present review describes the experimental evidence for interactions between neuropharmacological compounds and the classes of weak magnetic fields that might be encountered in our daily environments. Whereas drugs mediate their effects through specific spatial (molecular) structures, magnetic fields mediate their effects through specific temporal patterns. Very weak (microT range) physiologically-patterned magnetic fields synergistically interact with drugs to strongly potentiate effects that have classically involved opiate, cholinergic, dopaminergic, serotonergic, and nitric oxide pathways. The combinations of the appropriately patterned magnetic fields and specific drugs can evoke changes that are several times larger than those evoked by the drugs alone. These novel synergisms provide a challenge for a future within an electromagnetic, technological world. They may also reveal fundamental, common physical mechanisms by which magnetic fields and chemical reactions affect the organism from the level of fundamental particles to the entire living system
Experiences of clinical psychologists working in palliative care:A qualitative study
Background Compassion fatigue refers to the emotional and physical exhaustion felt by professionals in caring roles, whereas compassion satisfaction encompasses the positive aspects of helping others. Levels of compassion satisfaction and fatigue have been found to be inconsistent in palliative care professionals, which could have serious implications for patients, professionals and organisations. Objectives This study explored the experiences of clinical psychologists working in palliative care, all worked with adults with cancer, to gain an understanding of the impact this work has on their self and how they manage this. Methods A qualitative approach was taken, using semi‐structured interviews and interpretative phenomenological analysis. Results Three superordinate themes were identified: commitment, existential impact on the self and the oracle. The participants' experiences were characterised by the relationship between themselves and their patients, the influence of working in palliative services on their world view and the impact of organisational changes. Differences between working as a clinical psychologist in palliative care versus non‐palliative settings were considered. Conclusions Professionals working in palliative care should be supported to reflect on their experiences of compassion and resilience, and services should provide resources that facilitate staff to practice positive self‐care to maintain their well‐being
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