High luminosity interaction region design for collisions with detector solenoid

An innovatory interaction region has been recently conceived and realized on the Frascati DA{\Phi}NE lepton collider. The concept of tight focusing and small crossing angle adopted until now to achieve high luminosity in multibunch collisions has evolved towards enhanced beam focusing at the interaction point with large horizontal crossing angle, thanks to a new compensation mechanism for the beam-beam resonances. The novel configuration has been tested with a small detector without solenoidal field yielding a remarkable improvement in terms of peak as well as integrated luminosity. The high luminosity interaction region has now been modified to host a large detector with a strong solenoidal field which significantly perturbs the beam optics introducing new design challenges in terms of interaction region optics design, beam transverse coupling control and beam stay clear requirementsComment: 3 pages, 4 figures, presented to the IPAC10 conferenc

Rapid and accurate fatigue assessment by an efficient critical plane algorithm: application to a FSAE car rear upright

The topic of material fatigue is widely discussed and researched in both scientific and industrial communities. Fatigue damage remains a significant issue for both metallic and non-metallic components, leading to unforeseen failures of in-service parts. Critical plane methods are particularly recommended in case of multiaxial fatigue assessment and have gained relevance as they allow for the identification of the component's critical location and early crack propagation. However, the standard method for calculating critical plane factors is time-consuming, utilizing nested for/end loops and, for that, is mainly applied in a research context, or when critical regions are already known. In many cases, the critical area of a component cannot be identified due to complex geometries and loads or time constraints. This becomes particularly relevant after topological optimization of components and, more generally, in lightweight design. An efficient algorithm for critical plane factors evaluation have been recently proposed by the authors. The algorithm applies to all critical plane factors that require the maximization of a specific parameter based on stress and strain components or a combination of them. The methodology is based on tensor invariants and coordinates transformation law. This paper presents and validate the proposed methodology through an automotive case study: the new algorithm was tested on a rear upright of a FSAE car, having complex geometry, subjected to non-proportional loading conditions. The efficient algorithm showed a significant reduction in computation time compared to the (blind search-for) standard plane scanning method, without any loss in solution accuracy

Frequency analysis of random fatigue: setup for an experimental study

The frequency-domain approach to fatigue life estimation in random loading has been largely investigated due to its computational advantages, and several methods for the frequency translation of the most common time-domain methods have been proposed. Between the most known frequency methods there are the Bendat's Method, valid for narrow-band signals, and the Dirlik's formula, which is considered the best result for wide-band signals. However, the great part of the frequency methods takes the rainflow count as a reference time-domain method and uses the rainflow damage computation as the exact value to emulate. Therefore, very few experimental data for fatigue life of mechanical components subject to random loads are available in the literature. This work presents the setup for a series of experimental tests for specimens subjected to random loads, aiming at achieving experimental data to compare with the results provided by frequency methods. After a brief description of the materials used for the setup, the two-step test concept is described: firstly, the specimen will be subjected to random loads obtained by a certain PSD for an amount of time which should nominally cause a 30% of damage; then, the fatigue test will be ended on a resonance testing machine to compute the actual residual fatigue life of the specimen; this two-step testing also allows to reduce the time requested for the tests. The test bench developed for the experimental investigation is described in the paper, together with the results of some preliminary tests, aimed at verifying the feasibility of the conceived procedure

Numerical-experimental characterization of the dynamic behavior of PCB for the fatigue analysis of PCBa

In today's highly digitized and mechatronics-based world, the need for reliable and cost-effective electronic components has become essential. The reliability of these components is not only based on their electrical and circuit aspects but also on their structural properties. This paper presents a study carried out on two-layer Printed Circuit Boards (PCBs) of rectangular shape, which are representative of many industrial applications. The aim of this study is to compare different numerical models, developed in Ansys Workbench and in a FEM software specifically designed for circuit boards, with experimental tests to determine the most interesting ones for further studies on Printed Circuit Board Assemblies (PCBAs). The comparison includes both static and dynamic behaviors, tested through isostatic bending tests and dynamic analyses with a shaker and a fiber optic laser. The models developed are capable of reproducing statics and dynamics of PCBs with varying degrees of accuracy and numerical complexity. However, increasing the details of the models does not always correspond to an increase in accuracy in reproducing the dynamic behavior. Prior to the experimental dynamic analysis, the influence of constraints’ modeling strategies and damping on the first eigenmode was studied, and the results were used to set up tests and simulations to achieve more consistent results. Future work will extend the dynamic characterization to PCBAs by populating the studied PCBs with components, and continue with the study of predictive models for their structural reliability

Applicability of wild mushrooms to monitor environmental contamination of europium in Leicester, England

BACKGROUND AND AIM: Although the current levels of europium (Eu) in topsoils monitored across Leicestershire (UK) did not represent an oral/dermal toxic risk for the population, wild mushrooms were collected in the same areas to gain a better picture of its environmental distribution and risks. METHOD: 106 mushrooms were collected from Leicester city and Bradgate Park, and species were identified by DNA barcoding. Eu was monitored by ICP-MS in cleaned/dried/homogenised mushrooms [LoD=0.00056 µg/g dry weight (dw)] and in 850 topsoils collected in these areas. RESULTS: Eu concentrations were higher in mushrooms collected in urban areas, although without significance (median and ranges, in µg/g dw): 0.0016 (0.0004-0.2891) vs. 0.0013 (0.00036-0.0529), which might be attributed to fertilisers. However, levels of Eu varied between mushrooms collected across the four cardinal subareas in which the city was divided (p-value=7E-9), which might indicate differences in urbanisation, as Eu is used in flat screen displays and optical fibres. Although a correlation between the content of Eu in mushrooms and their respective topsoil/subareas was not found, a similar distribution was found. Thus, significantly higher median concentrations of Eu were found in the NE (0.0047, 0.8110) and lower in the NW (0.00087, 0.5960), in mushrooms and topsoils (all in µg/g dw and µg/g, respectively). Moreover, Eu significantly varied between the three main mushroom species collected (ranges, in µg/g dw; p-value=7E-15): Agaricus bitorquis (edible; 0.00079-0.00706), Panaeolus foenisecii (poisonous; 0.00104-0.17146) and Mycena citrinomarginata (unclassified; 0.00123-0.07117). Moreover, Eu was only detected in 54.5% of the A. bitorquis samples, although detected in all the other main species collected. CONCLUSIONS: The levels of Eu found were similar/lower than those reported in other major monitoring studies performed in other European countries, suggesting that the environmental presence of Eu would represent a minimal risk for Leicestershires population, including those individuals that pick up wild mushrooms for consumption

CTF3: Design of Driving Beam Combiner Ring

In CTF3 the beam compression of the driving beam structure between the main linac and the decelerating section is obtained with a delay loop and a combiner ring which increase the pulse current by a factor 10. The design of the combiner ring is presented. Tunable isochronicity condition, corrected up to second order, should assure preservation of the correlation in the longitudinal phase space during the compression. Path-length tuning devices are included in the combiner ring layout to compensate for orbit variations

High luminosity interaction region design for collisions inside high field detector solenoid

An innovatory interaction region has been recently conceived and realized on the Frascati DA{\Phi}NE lepton collider. The concept of tight focusing and small crossing angle adopted to achieve high luminosity in multibunch collisions has evolved towards enhanced beam focusing at the interaction point with large horizontal crossing angle, thanks to a new compensation mechanism for the beam-beam resonances. The novel configuration has been tested with a small detector without solenoidal field yielding a remarkable improvement in terms of peak as well as integrated luminosity. The high luminosity interaction region has now been modified to host a large detector with a strong solenoidal field which significantly perturbs the beam optics introducing new design challenges in terms of interaction region optics design, beam transverse coupling control and beam stay clear requirements. Interaction region design criteria as well as the luminosity results relevant to the structure test are presented and discussed.Comment: 12 pages, 9 figures, submitted to JINS

Building a DMU e-Biology resource for health sciences’ students.

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI linkThe BSc Biomedical Science (BMS) programme at De Montfort University (DMU, Leicester, UK) is accredited by the Institute of Biomedical Science (IBMS). Students enrolled within this programme acquire highly sought after skills related with human health sciences to work in: pathology departments in hospitals; research institutions; biotechnology and pharmaceutical industries; and the education sector to name a few. The degree recruits a large number of students with currently around 600 students enrolled on this programme at DMU. Despite pre-entry requirements of knowledge of subjects related to human biology, biology or chemistry, we have noted that first year students require basic support in STEM subjects (biology, chemistry and mathematics) in modules such as “Basic Microbiology”, “Basic Anatomy and Physiology” and “Chemistry for the Biosciences”. This support is especially necessary for students that come from non-traditional routes such as Business and Technology Education Council (BTEC) routes. Moreover, usually topics related with microbiology and human diseases are challenging for students, often causing stress impacting their overall performance and experience. A group of BMS academics at DMU in conjunction with universities in the European Union (EU; e.g. University of San Pablo CEU, Spain) have started to design, create and develop a series of e-learning resources or units in human biology and BMS for undergraduate students that study health sciences degrees in the EU. These units are being uploaded onto the DMU web server (http://parasitology.dmu.ac.uk/) and will be only accessible for students from participating universities during the first phase of this project (2017/18 course) in which comprehensive feedback will be collected. This web server space has three sections or modules (theoretical section, virtual laboratory and microscope) in which the new e-learning resources will be preliminary accommodated. These units will be interactive and easy to follow, and will cover basic human biology (e.g. cells, cell structure), human anatomy and physiology, histology and basic microbiology, which will be embedded in a theoretical module named DMU e-Biology within the above URL link. They will include formative assessments and case studies throughout each unit. In addition, a series of practical units are being developed which describe routine practical elements in any biomedical laboratory such as laboratory materials, pipetting, molecular techniques (e.g. PCR), cell culture (e.g. use of biological safety cabinet) and histological techniques (e.g. use of microtome, staining techniques). The development of this teaching and learning resource will cover a gap in the traditional teaching and learning methods that are currently used and provided in the participating universities. The DMU e-Biology will aid to our undergraduate students to gain knowledge in human biology and microbiology by promoting self-learning. We consider that the DMU e-Biology will help overcome spatiotemporal, equipment and resource barriers. Additionally, it may help student retention as currently about a 10% of our first year students fail to continue BMS at DMU. Finally, the creation of the DMU e-Biology will also provide support to the DMU Student Retention and Attainment Strategy 2016-2020 through the DMU Student Learning Hub, which is currently under development