Photon sensitivity of superheated drop at room temperature

It has been reported so far that superheated drop detector made of R-12 at room temperature are sensitive to neutrons yet insensitive to photons. This property makes its use as one of the most useful neutron dosimeter. The photon sensitivity of R12 at room temperature when exposed to 59.54kev photons obtained from radioactive Am has been noted for the first time in our laboratory. This discovery is important nt only from the point of view of basic science but more important to the users of R12 in neutron dosimetry to take note of this in assessing the neutron dose correctly.Comment: 3pages, 1 fig. Nuclear Instruments and Method A, 2000, (accepted

Superheated drop as a neutron spectrometer

Superheated drops are known to vaporise when exposed to energetic nuclear radiation since the discovery of bubble chamber. As the degree of superheat increases in a given liquid, less and less energetic neutrons are required to cause nucleation. This property of superheated liquids are being utilised to develope the neutron spectromer. A new principle of neutron spectrometry using Superheated liquid are developed and the developed principle has been tested by Am-Be neutron source.Comment: 9 pages, 8 figures. accepted in Nucl.Instru.MethA,200

Cluster optimisation using Cgroups at a tier-2

The Linux kernel feature Control Groups (cgroups) has been used to gather metrics on the resource usage of single and eight-core ATLAS workloads. It has been used to study the effects on performance of a reduction in the amount of physical memory. The results were used to optimise cluster performance, and consequently increase cluster throughput by up to 10%

Predictors of health-related quality of life (HRQL) in people with chronic aphasia

Background: In recent years, quality of life measures have been used increasingly to evaluate the effectiveness of services or interventions. For people with chronic disabilities, research has focused on identifying the main predictors of their health-related quality of life (HRQL), in order to address the issue of how to meet their needs in rehabilitation in a more holistic way. Aims: This study assessed the main predictors of HRQL in people with chronic aphasia following stroke. We investigated the relationship between HRQL and various demographic and stroke-related variables and other variables that have been associated with HRQL in stroke survivors (e.g., emotional distress, daily activities, social support). Methods: A cross-sectional design was adopted. A cluster sampling framework was used to recruit participants with chronic aphasia (> 1 year) from three different sites. Questionnaires and assessments on the different variables were administered to all participants by a speech and language therapist, in an interview format. Multiple regression analysis was used to assess what were the main predictors of HRQL in people with aphasia. Results: Of 95 participants, 83 (87%) were able to self-report on all the assessments. Emotional distress, involvement in home and outdoors activities, extent of communication disability, and number of comorbid conditions explained 52% of the variance in HRQL (adjusted R 2 = .52). Stroke type (infarct vs haemorrhage), time post-onset, and demographic variables (gender, ethnicity, marital status, employment status, and socioeconomic status) were not significantly associated with HRQL in these participants. Conclusions: Increased distress, reduced involvement in activities, increased communication disability, and comorbidity predict poorer HRQL in people with chronic aphasia after stroke. Service providers need to take these factors into account when designing intervention programmes

A container model for resource provision at a WLCG Tier-2

Containers are more and more becoming prevalent in Industry as the standard method of software deployment. They have many benefits for shipping software by encapsulating dependencies and turning complex software deployments into single portable units. Similar to Virtual Machines, but with a lower overall resource requirement, greater flexibility and more transparency they are a compelling choice for software deployment. The use of containers is becoming attractive to WLCG experiments as a means to encapsulate their payloads, ensure that userland environments are consistent and to segregate running jobs from one another to improve isolation. Technologies such as Docker and Singularity are already being used and tested by larger WLCG experiments along with CERN IT. Our purpose in this paper is to explore the use of containers at a medium to large WLCG Tier-2 as a method of reducing the manpower required to run such a site. By examining the requirements of WLCG payloads (such as the availability of CVMFS, Trust Anchors or VOMS information) a model of a contained compute platform is developed and presented. Along with providing compute it standardised monitoring solutions can be bundled to provide a complete toolbox for local System Administrators to provide resources quickly and securely

Projected pH reductions by 2100 might put deep North Atlantic biodiversity at risk

This study aims to evaluate the potential for impacts of ocean acidification on North Atlantic deep-sea ecosystems in response to IPCC AR5 Representative Concentration Pathways (RCPs). Deep-sea biota is likely highly vulnerable to changes in seawater chemistry and sensitive to moderate excursions in pH. Here we show, from seven fully coupled Earth system models, that for three out of four RCPs over 17% of the seafloor area below 500 m depth in the North Atlantic sector will experience pH reductions exceeding ?0.2 units by 2100. Increased stratification in response to climate change partially alleviates the impact of ocean acidification on deep benthic environments. We report on major pH reductions over the deep North Atlantic seafloor (depth >500 m) and at important deep-sea features, such as seamounts and canyons. By 2100, and under the high CO2 scenario RCP8.5, pH reductions exceeding ?0.2 (?0.3) units are projected in close to 23% (~15%) of North Atlantic deep-sea canyons and ~8% (3%) of seamounts – including seamounts proposed as sites of marine protected areas. The spatial pattern of impacts reflects the depth of the pH perturbation and does not scale linearly with atmospheric CO2 concentration. Impacts may cause negative changes of the same magnitude or exceeding the current target of 10% of preservation of marine biomes set by the convention on biological diversity, implying that ocean acidification may offset benefits from conservation/management strategies relying on the regulation of resource exploitation

Using Continous Deployment techniques to manage software change at a WLCG Tier-2

Continuous Integration (CI) and Continuous Development (CD) are common techniques in software development. Continuous Integration is the practice of bringing together code from multiple developers into a single repository, while Continuous Development is the process by which new releases are automatically created and tested. CI/CD pipelines are available in popular automation tools such as GitLab, and act to enhance and accelerate the software development process. Continuous Deployment, in which automation is employed to push new software releases into the production environment, follows naturally from CI/CD, but is not as well established due to business and legal requirements. Such requirements do not exist in the Worldwide LHC Compute Gird (WLCG), making the use of continuous deployment to simplify the management of grid resources an attractive proposition. We have developed work presented previously on containerised worker node environments by introducing continuous deployment techniques and tooling, and show how these, in conjunction with CI/CD, can reduce the management burden at a WLCG Tier-2 resource. In particular, benefits include reduced downtime as a result of code changes and middleware updates

Percolation model for structural phase transitions in Li1−x_{1-x}Hx_xIO3_3 mixed crystals

A percolation model is proposed to explain the structural phase transitions found in Li$_{1-x}$H$_x$IO$_3$ mixed crystals as a function of the concentration parameter $x$. The percolation thresholds are obtained from Monte Carlo simulations on the specific lattices occupied by lithium atoms and hydrogen bonds. The theoretical results strongly suggest that percolating lithium vacancies and hydrogen bonds are indeed responsible for the solid solution observed in the experimental range $0.22 < x < 0.36$.Comment: 4 pages, 2 figure

Anomalous Neutrino Interaction, Muon g-2, and Atomic Parity Nonconservation

We propose a simple unified description of two recent precision measurements which suggest new physics beyond the Standard Model of particle interactions, i.e. the deviation of $\sin^2 \theta_W$ in deep inelastic neutrino-nucleon scattering and that of the anomalous magnetic moment of the muon. Our proposal is also consistent with a third precision measurement, i.e. that of parity nonconservation in atomic Cesium, which agrees with the Standard Model.Comment: 9 pages, including 1 figure, latest muon g-2 information adde

General Stability Analysis of Synchronized Dynamics in Coupled Systems

We consider the stability of synchronized states (including equilibrium point, periodic orbit or chaotic attractor) in arbitrarily coupled dynamical systems (maps or ordinary differential equations). We develop a general approach, based on the master stability function and Gershgorin disc theory, to yield constraints on the coupling strengths to ensure the stability of synchronized dynamics. Systems with specific coupling schemes are used as examples to illustrate our general method.Comment: 8 pages, 1 figur