Synthesis, structural characterisation and solution behaviour of high symmetry lanthanide triflate complexes with the sterically demanding phosphine oxides Cy3PO and tBu3PO

The synthesis and characterisation of lanthanide trifluoromethane sulfonate (Ln(OTf)3) complexes with tricyclohexylphosphine oxide, (Cy3PO) and tritert-butylphosphine oxide, (tBu3PO) is described. The structures of [Ln(H2O)5(Cy3PO)2].2R3PO.[OTf]3 (Ln = Pr, Tm R = Cy Ln = Nd R = tBu) are pentagonal bipyramidal with an equatorial plane of five H2O and two axial Cy3PO. The remaining Cy3PO molecules are hydrogen bonded to the coordinated water molecules as are the triflate anions. Solution NMR spectroscopy shows the triflate ions remain associated with the complexes in CDCl3 solution. Lanthanide induced shifts in the 19-F and 31-P NMR spectra confirm that one structure is present for all the lanthanides with an additional structure for the heavier metals. The acidity of the complexes has been examined by 31-P NMR spectroscopy of the reactions between [Ln(H2O)5(Cy3PO)2].2Cy3PO.[OTf]3 (Ln = La, Eu, Er, Lu) and phosphines PR3 (R = Ph, mesityl and Cy) and Ph2PC2H4PPh2 and Ph2PC3H6PPh2 . Protonation of the more basic phosphines and H-bonding to the less basic phosphines is observed

Seismic and vibration signal analysis and monitoring using LabView

Every year there are around 20 earthquakes of magnitude 7 or above . This kind of seismic events are potentially destructive and can cause several structural damage, economic and human loss. In order to perform an efficient risk management and prevention work geophysics must be equipped with suitable software and hardware tools. Seismic studies comprise not only risk management but earth structure studies that are useful in gas and oil prospections. Vibration monitoring has also turned in a very useful scientific approach to deal with structural safety and maintenance. Among these devices, MEMS accelerometer combines great performance with low costs, characteristics that have made it one of the most popular devices when it comes to this task. Seismic analysis software has been developed using LabVIEW. The software decodes SAC data files and retrieves important seismic parameters like arrival wave times, location and magnitude. The precision and performance reached is acceptable for the scope of this project and it could be used as a domestic seismic analyser but not for its use in a professional seismic station. The seismic data for the system evaluation was retrieved from IRIS database. A vibration DAQ and monitoring module has been designed and implemented. It successfully measures and monitors acceleration versus time and the signal’s spectra. Zooming options were included in order to make easier the background noise and ambient vibration study. An instant and maximum earthquake intensity gauge was programmed to give an idea of the experienced event potential danger. The user can selectively save acceleration time responses in LVM format. An analogue output was implemented. It is capable of reading acceleration versus time responses saved in LVM and SAC files and output them using a DAQ card analogue output function. This voltage can be seen in an oscilloscope or input to other devices. In order to acquire and save the analogue waveforms created with the previous function an analogue input was included as an initial objective in the Scheme of Work. However, it was dropped in the final implementation because it was considered that its function was too similar to the vibration DAQ module and it did not have enough practical application

Development of an optimized converter layer for silicon carbide based neutron sensor for the detection of fissionable materials

Here, we describe the early stage design, construction and testing of a miniature silicon carbide diode neutron sensing instrument. It is intended that a more mature version of this instrument will be used as part of a robotic manipulator to investigate various parts of the stricken Fukushima nuclear power plant. Here, three such silicon carbide based proto-type sensors have been created, two of which have differing thicknesses of boron-10 deposited on, with the final one left bare. The thicknesses and materials chosen have been informed via Monte Carlo software (MCNP 6.2) which was also used to assess the suitability of two other potential converter materials – Lithium-6 and gadolinium-157. The work goes on to describe the design, construction and testing of the prototype device at two sites around the UK. The project is part of a UK/Japanese collaboration between Lancaster University and Kyoto University and is supported by an EPSRC grant via the UK Japan Civil nuclear research program

Development of an Optimized Converter Layer for a Silicon-Carbide-Based Neutron Sensor for the Detection of Fissionable Materials

We describe the early stage development of a miniature silicon carbide neutron sensor, for applications including robotic monitoring at the Fukushima Daiichi nuclear power plant, specifically, within the primary containment vessel for fuel debris detection and retrieval. Monte Carlo simulations using MCNP 6.2 and Geant4 10.05.01 are used to investigate and optimize converter layers for thermal neutron detection. Performance of a 10B4C:SiC detector system is investigated in detail and a neutron detection efficiency ∼4% is predicted, with a gamma discrimination ratio of the order of 105

Inter-ethnic relations of teenagers in England’s schools: the role of school and neighbourhood ethnic composition

The paper presents an empirical analysis of inter-ethnic relations among adolescents in England’s schools, the first national study of schools throughout England to relate inter-ethnic attitudes to both school and area ethnic composition. We combine survey data on ‘warmth’ of feeling for specific ethnic groups, friendships and attitudes with administrative data on the shares of those groups at school and area level. We confirm that the pupils have warmer feelings for their own ethnic group than for others. Second, we show that in schools with more pupils from another ethnic group the gap between a pupil’s views of those from her own group and from another ethnic group is smaller. This is true for attitudes of the majority and of minority ethnic groups. Third, we show that school composition (interpreted as contact) mitigates area composition (interpreted as exposure)

Integrating the next generation: how school composition affects inter-ethnic attitudes

Drawing on new research, Simon Burgess and Lucinda Platt argue that greater mixing of pupils from different ethnicities would be beneficial for social integration

Active tectonics of the western Mediterranean: Geodetic evidence for roll back of a delaminated subcontinental lithospheric slab beneath the Rif Mountains, Morocco

Copyright 2006, Geological Society of America. See also: http://www.geosociety.org; http://atlas.geo.cornell.edu/morocco/publications/fadil2006.htmSurface deformation in Morocco derived from five years of GPS survey observations of a 22-station network, four continuously recording GPS stations, and four IGS stations in Iberia indicate roughly southward motion (~3 mm/yr) of the Rif Mountains, Morocco relative to stable Africa. Motion of the Rif is approximately normal to the direction of Africa-Eurasia relative motion, which is predominantly strike slip, and results in shortening of the Rif and subsequent crustal extension of the adjacent Alboran Sea region. The sense, and the N-S asymmetry of the observed deformation (i.e., no evidence for north-directed shortening in the Betic Mountains north of the Alboran Sea) cannot be easily explained in terms of crustal plate interactions suggesting that dynamic processes below the crust are driving the recent geologic evolution of the western Mediterranean. The model that best fits the observations involves delamination and southward roll back of the African lithospheric mantle under the Alboran and Rif domains

Periodicity in the BrO/SO2 molar ratios in the volcanic gas plume of Cotopaxi and its correlation with the Earth tides during the eruption in 2015

We evaluated NOVAC (Network for Observation of Volcanic and Atmospheric Change) gas emission data from the 2015 eruption of Cotopaxi volcano (Ecuador) for BrO/SO2 molar ratios. Statistical analysis of the data revealed a conspicuous periodic pattern with a periodicity of about two weeks in a three month time series. While the time series is too short to rule out a chance recurrence of transient geological or meteorological events as a possible origin for the periodic signal, we nevertheless took this observation as a motivation to examine the influence of natural forcings with periodicities of around two weeks on volcanic gas emissions. One strong aspirant with such a periodicity are the Earth tides, which are thus central in this study. We present the BrO/SO2 data, analyse the reliability of the periodic signal, discuss a possible meteorological or eruption-induced origin of this signal, and compare the signal with the theoretical ground surface displacement pattern caused by the Earth tides. Central result is the observation of a significant correlation between the BrO/SO2 molar ratios with the North-South and vertical components of the calculated tide-induced surface displacement with correlation coefficients of 47 % and 36 %, respectively. From all other investigated parameters, only the correlation between the BrO/SO2 molar ratios and the relative humidity in the local atmosphere resulted in a comparable correlation coefficient of about 33 %

Cerium(III) and cerium(IV) nitrate complexes of trialkylphosphine oxides

Abstract The reactions of ammonium cerium(IV) nitrate, (NH4)2Ce(NO3)6 (CAN) with trialkylphosphine oxides, R3PO (R= Et, iPropyl, nBu3, iBu3PO, tBu3PO, Cy3PO (Cy = cyclohexyl) and Oct3PO (Oct = n-octyl)) have been investigated by 31-P NMR spectroscopy in a variety of conditions. Reactions with acetone solutions of excess of CAN and R3PO and of solid CAN with chloroform solutions of R3PO and aqueous solutions of CAN with chloroform solutions of R3PO led to the observation of Ce(NO3)4(R3PO)2. 31-P NMR spectroscopy and conductimetric titration of acetone solutions of CAN with R3PO confirm the initial reactions is the formation of Ce(NO3)4(R3PO)2 (R = Et, Bu, Cy, Oct) followed by a slower reaction to form the ionic [Ce(NO3)3(R3PO)3][NO3]. The isolation of pure cop-lexes has not proved possible in most cases but crystals suitable for x-ray analysis were extracted in some instances. The structures of the Ce(IV) complexes [Ce(NO3)4(Cy3PO)2] and [Ce(NO3)3(Et3PO)3][NO3] and the related Ce(III) complexes [Ce(NO3)3(Cy3PO)3] and [Ce(NO3)3(H2O)3(Et3PO)] are reported

Magnetic Nanoparticle-Based Hyperthermia for Head & Neck Cancer in Mouse Models

In this study, magnetic iron oxide nanoparticle induced hyperthermia is applied for treatment of head and neck cancer using a mouse xenograft model of human head and neck cancer (Tu212 cell line). A hyperthermia system for heating iron oxide nanoparticles was developed by using alternating magnetic fields. Both theoretical simulation and experimental studies were performed to verify the thermotherapy effect. Experimental results showed that the temperature of the tumor center has dramatically elevated from around the room temperature to about 40oC within the first 5-10 minutes. Pathological studies demonstrate epithelial tumor cell destruction associated with the hyperthermia treatment