Search

Mastigimas anjosi is an important pest of Cedrela fissilis in the southeastern and southern regions of Brazil. The objective of the present study was to investigate the effect of the temperature, relative humidity, rainfall and natural enemies on the flight activity of adults and the movement of M. anjosi nymphs, with two sampling methods, yellow sticky traps and direct collections on the leaves of C. fissilis trees. The sex ratio of this pest was also assessed. The number of M. anjosi individuals was negatively correlated with the minimum and maximum temperatures, with a population peak in late May and early June 2017. The numbers of individuals of this psyllid was positively correlated with the relative humidity and rainfall. Larvae and adults of Cycloneda sanguinea , Hippodamia convergens adults and Atopozelus opsimus nymphs and adults preyed upon M. anjosi adults and nymphs on C. fissilis leaves in the field. Mastigimas anjosi sex ratio was 0.46. Information about sampling methods of M. anjosi and its natural enemies is presented and can contribute to the integrated management of this pest in the field.

This manuscript describes the commissioning of the Mini-CAPTAIN liquid argon detector in a neutron beam at the Los Alamos Neutron Science Center (LANSCE), which led to a first measurement of high-energy neutron interactions in argon. The Mini-CAPTAIN detector consists of a Time Projection Chamber (TPC) with an accompanying photomultiplier tube (PMT) array sealed inside a liquid-argon-filled cryostat. The liquid argon is constantly purified and recirculated in a closed-loop cycle during operation. The specifications and assembly of the detector subsystems and an overview of their performance in a neutron beam are reported., 21 pages, 27 figures

Background: Human growth is susceptible to damage from insults, particularly during periods of rapid growth. Identifying those periods and the normative limits that are compatible with adequate growth and development are the first key steps toward preventing impaired growth. Objective: This study aimed to construct international fetal growth velocity increment and conditional velocity standards from 14 to 40 weeks’ gestation based on the same cohort that contributed to the INTERGROWTH-21st Fetal Growth Standards. Study Design: This study was a prospective, longitudinal study of 4321 low-risk pregnancies from 8 geographically diverse populations in the INTERGROWTH-21st Project with rigorous standardization of all study procedures, equipment, and measurements that were performed by trained ultrasonographers. Gestational age was accurately determined clinically and confirmed by ultrasound measurement of crown-rump length at Results: Peak velocity was observed at a similar gestational age: 16 and 17 weeks’ gestation for head circumference (12.2 mm/wk), and 16 weeks’ gestation for abdominal circumference (11.8 mm/wk) and femur length (3.2 mm/wk). However, velocity growth slowed down rapidly for head circumference, biparietal diameter, occipitofrontal diameter, and femur length, with an almost linear reduction toward term that was more marked for femur length. Conversely, abdominal circumference velocity remained relatively steady throughout pregnancy. The change in velocity with gestational age was more evident for head circumference, biparietal diameter, occipitofrontal diameter, and femur length than for abdominal circumference when the change was expressed as a percentage of fetal size at 40 weeks’ gestation. We have also shown how to obtain accurate conditional fetal velocity based on our previous methodological work. Conclusion: The fetal skeleton and abdomen have different velocity growth patterns during intrauterine life. Accordingly, we have produced international Fetal Growth Velocity Increment Standards to complement the INTERGROWTH-21st Fetal Growth Standards so as to monitor fetal well-being comprehensively worldwide. Fetal growth velocity curves may be valuable if one wants to study the pathophysiology of fetal growth. We provide an application that can be used easily in clinical practice to evaluate changes in fetal size as conditional velocity for a more refined assessment of fetal growth than is possible at present (https://lxiao5.shinyapps.io/fetal_growth/). The application is freely available with the other INTERGROWTH-21st tools at https://intergrowth21.tghn.org/standards-tools/.

Daylighting is a strategic topic to achieve sustainable buildings, so it is more and more imperative that it is implemented in architecture curricula to prepare a new generation of daylighting-oriented practitioners. In this frame, the DAYKE project (Daylight Knowledge in Europe) was set up to explore the level of knowledge about daylighting among European professionals and students. DAYKE-Europe was replicated as DAYKE-Italy to study the knowledge of daylight standards, metrics and software among Italian architecture students, and to compare it to that observed within DAYKE-Europe. A sample of 542 questionnaires were collected in five universities. Primary outcomes were: (i) a general low level of knowledge on daylighting was observed; the most cited metrics were the average daylight factor and the geometrical window-to-floor ratio, while climate-based daylight metrics were rarely mentioned; (ii) master science M.Sc. students reported more knowledge on daylight metrics and regulations than bachelor B.Sc. students, while the implementation of daylight metrics and strategies in projects was mainly deficient among B.Sc. students; (iii) compared to European students (DAYKE-Europe), Italian students showed a higher knowledge of daylight metrics and software (especially as for M.Sc. students), while the opposite was observed for standards, regulations and protocols. Based on the results, a reconsideration of daylight education in architecture curricula is recommended.

Results from the DAYKE-Italy project are presented. An investigation on daylighting in eight classrooms in five Italian universities was carried out through a combined approach: an ad-hoc survey administered to students to investigate how they perceive daylight in classroom, and numerical simulations (DIVA + ALFA) to calculate a set of objective metrics (daylight, circadian, and energy-related). A sample of 542 questionnaires was collected through two sessions and the subjective judgments were correlated to objective metrics. Results from descriptive and statistical analyses showed: (i) the correlation was significant for all daylight metrics: among them, average daylight factor and annual light exposure performed higher correlations compared to daylight autonomy, spatial daylight autonomy and useful daylight illuminance; (ii) rooms with a scarce or an optimal daylight provision (according to standards) were rated with comparable subjective score; (iii) the equivalent melanopic lux showed a higher correlation than daylight metrics based on the horizontal workplane; (iv) energy saving up to 50% can be achieved in the presence of high daylight provision and through daylight responsive controls; however, a relamping of fluorescent systems with LED system is recommended to optimize the consumption; furthermore, estimated saving correlated significantly with objective metrics.

The problem raised by the steadily increasing number of failures in ancient town walls has recently attracted much interest. This typology of cultural heritage has always played a critical role in shaping local identities and still holds great potential as a cultural resource but poses substantial challenges in management terms. In fact, multi-disciplinary methodologies for their study and analysis are missing. The MO.M.U. project aims to safeguard ancient town walls in Tuscany (Italy) by introducing an integrated framework for their knowledge, diagnostic, assessment, monitoring and management. The proposed approach employs innovative non-invasive technologies and introduces a multi-hazard risk prioritisation methodology to address preventive conservation and programme interventions.

Summary Background Preterm birth is a major global health challenge, the leading cause of death in children under 5 years of age, and a key measure of a population's general health and nutritional status. Current clinical methods of estimating fetal gestational age are often inaccurate. For example, between 20 and 30 weeks of gestation, the width of the 95% prediction interval around the actual gestational age is estimated to be 18–36 days, even when the best ultrasound estimates are used. The aims of this study are to improve estimates of fetal gestational age and provide personalised predictions of future growth. Methods Using ultrasound-derived, fetal biometric data, we developed a machine learning approach to accurately estimate gestational age. The accuracy of the method is determined by reference to exactly known facts pertaining to each fetus—specifically, intervals between ultrasound visits—rather than the date of the mother's last menstrual period. The data stem from a sample of healthy, well-nourished participants in a large, multicentre, population-based study, the International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH-21st). The generalisability of the algorithm is shown with data from a different and more heterogeneous population (INTERBIO-21st Fetal Study). Findings In the context of two large datasets, we estimated gestational age between 20 and 30 weeks of gestation with 95% confidence to within 3 days, using measurements made in a 10-week window spanning the second and third trimesters. Fetal gestational age can thus be estimated in the 20–30 weeks gestational age window with a prediction interval 3–5 times better than with any previous algorithm. This will enable improved management of individual pregnancies. 6-week forecasts of the growth trajectory for a given fetus are accurate to within 7 days. This will help identify at-risk fetuses more accurately than currently possible. At population level, the higher accuracy is expected to improve fetal growth charts and population health assessments. Interpretation Machine learning can circumvent long-standing limitations in determining fetal gestational age and future growth trajectory, without recourse to often inaccurately known information, such as the date of the mother's last menstrual period. Using this algorithm in clinical practice could facilitate the management of individual pregnancies and improve population-level health. Upon publication of this study, the algorithm for gestational age estimates will be provided for research purposes free of charge via a web portal. Funding Bill & Melinda Gates Foundation, Office of Science (US Department of Energy), US National Science Foundation, and National Institute for Health Research Oxford Biomedical Research Centre.

We report the first measurement of the neutron cross section on argon in the energy range of 100-800 MeV. The measurement was obtained with a 4.3-hour exposure of the Mini-CAPTAIN detector to the WNR/LANSCE beam at LANL. The total cross section is measured from the attenuation coefficient of the neutron flux as it traverses the liquid argon volume. A set of 2,631 candidate interactions is divided in bins of the neutron kinetic energy calculated from time-of-flight measurements. These interactions are reconstructed with custom-made algorithms specifically designed for the data in a time projection chamber the size of the Mini-CAPTAIN detector. The energy averaged cross section is $0.91 \pm{} 0.10~\mathrm{(stat.)} \pm{} 0.09~\mathrm{(sys.)}~\mathrm{barns}$. A comparison of the measured cross section is made to the GEANT4 and FLUKA event generator packages., Comment: 5 pages, 1 table, 3 figures, submitted to Physical Review Letters

Purpose Single-agent gemcitabine became standard first-line treatment for advanced pancreatic cancer after demonstration of superiority compared with fluorouracil. The Gruppo Italiano Pancreas 1 randomized phase III trial aimed to compare gemcitabine plus cisplatin versus gemcitabine alone (ClinicalTrials.gov ID NCT00813696). Patients and Methods Patients with locally advanced or metastatic pancreatic cancer, age 18 to 75 years, and Karnofsky performance status (KPS) ≥ 50, were randomly assigned to receive gemcitabine (arm A) or gemcitabine plus cisplatin (arm B). Arm A: gemcitabine 1,000 mg/m2 weekly for 7 weeks, and, after a 1-week rest, on days 1, 8, and 15 every 4 weeks. Arm B: cisplatin 25 mg/m2 added weekly to gemcitabine, except cycle 1 day 22. Primary end point was overall survival. To have 8% power of detecting a 0.74 hazard ratio (HR) of death, with bilateral α .05, 355 events were needed and 400 patients planned. Results Four hundred patients were enrolled (arm A: 199; arm B: 201). Median age was 63, 59% were male, 84% had stage IV, and 83% had KPS ≥ 80. Median overall survival was 8.3 months versus 7.2 months in arm A and B, respectively (HR, 1.10; 95% CI, 0.89 to 1.35; P = .38). Median progression-free survival was 3.9 months versus 3.8 months in arm A and B, respectively (HR, 0.97; 95% CI, 0.80 to 1.19; P = .80). The objective response rate was 10.1% in A and 12.9% in B (P = .37). Clinical benefit was experienced by 23.0% in A and 15.1% in B (P = .057). Combination therapy produced more hematologic toxicity, without relevant differences in nonhematologic toxicity. Conclusion The addition of weekly cisplatin to gemcitabine failed to demonstrate any improvement as first-line treatment of advanced pancreatic cancer.

The direct search for dark matter is entering a period of increased sensitivity to the hypothetical Weakly Interacting Massive Particle (WIMP). One such technology that is being examined is a scintillation only noble liquid experiment, MiniCLEAN. MiniCLEAN utilizes over 500 kg of liquid cryogen to detect nuclear recoils from WIMP dark matter and serves as a demonstration for a future detector of order 50 to 100 tonnes. The liquid cryogen is interchangeable between argon and neon to study the A2 dependence of the potential signal and examine backgrounds. MiniCLEAN utilizes a unique modular design with spherical geometry to maximize the light yield using cold photomultiplier tubes in a single-phase detector. Pulse shape discrimination techniques are used to separate nuclear recoil signals from electron recoil backgrounds. MiniCLEAN will be spiked with additional 39Ar to demonstrate the effective reach of the pulse shape discrimination capability. Assembly of the experiment is underway at SNOLAB and an update on the project is given., Los Alamos National Laboratory, United States. Department of Energy. Office of Science, National Science Foundation (U.S.), National Institute of Standards and Technology (U.S.)

There are a number of papers that calculate how the limits or positive results of current experiments would be if some specific twist is applied to the standard interpretation framework (e.g., SI interactions with fp = fn). These works are usually not performed by members of the experiments, and therefore make very simple assumptions on experimental details like efficiencies. Nevertheless, it is possible to retain this type of information without actually knowing it, by starting from the final exclusion plots and working backwards. This possibility is discussed and exemplified.

MiniCLEANis a single-phase noble liquid scintillator experiment designed to detect nuclear recoils due to weakly interacting massive particles hypothesized to constitute the dark matter. The principle of the detector is to monitor scintillation light resulting from ionizing radiation using 92 photomultiplier tubes surrounding a spherical target. Photomultiplier tube response is known to be affected by sub-Gauss magnetic fields, so that the Earth's magnetic field has a non-negligible effect on the photomultiplier tube efficiency. In this experiment, the crucial nuclear recoil energy threshold depends on the ability to detect very small amounts of scintillation light; high photomultiplier tube efficiency is critical. Therefore, the MiniCLEAN collaboration has designed active compensation coils to mitigate the Earth's local magnetic field. Two features of the experimental environment make this situation unique: first, the underground laboratory (SNOLAB) is located in a nickel mine, so that direct measurement of the potentially distorted geomagnetic field is mandatory. Second, the close proximity of another experiment based on photomultiplier tubes (DEAP-3600) makes the compensating field outside our detector a concern. An additional complication is that MiniCLEANis surrounded by a steel water tank needed for shielding and a muon veto composed of four strings of 12 photomultipliers suspended in the water. We describe our design based on these considerations, survey data, field calculations and simulations of the photomultiplier tube response.

Objectives Microindentation has the potential to measure the stiffness of an individual patient’s bone. Bone stiffness plays a crucial role in the press-fit stability of orthopaedic implants. Arming surgeons with accurate bone stiffness information may reduce surgical complications including periprosthetic fractures. The question addressed with this systematic review is whether microindentation can accurately measure cortical bone stiffness. Methods A systematic review of all English language articles using a keyword search was undertaken using Medline, Embase, PubMed, Scopus and Cochrane databases. Studies that only used nanoindentation, cancellous bone or animal tissue were excluded. Results A total of 1094 abstracts were retrieved and 32 papers were included in the analysis, 20 of which used reference point indentation, and 12 of which used traditional depth-sensing indentation. There are several factors that must be considered when using microindentation, such as tip size, depth and method of analysis. Only two studies validated microindentation against traditional mechanical testing techniques. Both studies used reference point indentation (RPI), with one showing that RPI parameters correlate well with mechanical testing, but the other suggested that they do not. Conclusion Microindentation has been used in various studies to assess bone stiffness, but only two studies with conflicting results compared microindentation with traditional mechanical testing techniques. Further research, including more studies comparing microindentation with other mechanical testing methods, is needed before microindentation can be used reliably to calculate cortical bone stiffness. Cite this article: M. Arnold, S. Zhao, S. Ma, F. Giuliani, U. Hansen, J. P. Cobb, R. L. Abel, O. Boughton. Microindentation – a tool for measuring cortical bone stiffness? A systematic review. Bone Joint Res 2017;6:542–549. DOI: 10.1302/2046-3758.69.BJR-2016-0317.R2.

Many current and future dark matter and neutrino detectors are designed to measure scintillation light with a large array of photomultiplier tubes (PMTs). The energy resolution and particle identification capabilities of these detectors depend in part on the ability to accurately identify individual photoelectrons in PMT waveforms despite large variability in pulse amplitudes and pulse pileup. We describe a Bayesian technique that can identify the times of individual photoelectrons in a sampled PMT waveform without deconvolution, even when pileup is present. To demonstrate the technique, we apply it to the general problem of particle identification in single-phase liquid argon dark matter detectors. Using the output of the Bayesian photoelectron counting algorithm described in this paper, we construct several test statistics for rejection of backgrounds for dark matter searches in argon. Compared to simpler methods based on either observed charge or peak finding, the photoelectron counting technique improves both energy resolution and particle identification of low energy events in calibration data from the DEAP-1 detector and simulation of the larger MiniCLEAN dark matter detector., Comment: 16 pages, 16 figures

How to cite this article: Valentini V., Marazzi F., Bossola M., Micciche F., Nardone L., Balducci M., Dinapoli N., Bonomo P., Autorino R., Silipigni S., Giuliani F., Tamanti C., Mele M.C. & Martorana G.E. (2012) Nutritional counselling and oral nutritional supplements in head and neck cancer patients undergoing chemoradiotherapy. J Hum Nutr Diet. 25, 201–208 Abstract Background: The role of nutritional counselling (NC) with or without oral nutritional supplements (ONS) in patients receiving chemoradiotherapy (CRT) for head and neck cancer (HNC) still remains to be clearly defined, particularly with regard to CRT-related toxicity. Methods: Patients undergoing CRT for HNC received NC by the dietitian within the first 4 days of radiotherapy and weekly for the course of radiotherapy (approximately 6 weeks). A weekly supply of oral nutrition supplements [1560 kJ (373 kcal) per 100 g] for up to 3 months was provided to all patients. Results: Twenty-one patients completed CRT. Mucositis G3 developed in seven (33.3%) patients, whereas mucositis G4 was absent. Dysphagia was present before the start of treatment in four patients. In the remaining 17 patients, dysphagia G3 developed during/at the end of treatment in five cases. The percentage of patients interrupting anti-neoplastic treatment for was 28% for ≥6 days, 28% for 3–5 days and 44% for 0–2 days. Mucositis G3 frequency was lower in patients with a baseline body mass index (BMI, kg m−2) ≥25 (two out of 12; 16.6%) than in patients with BMI 30 cm than in those with a mid arm circumference in the range 28.1–30 cm and

We present a study on the role of dislocations and impurities for the unintentional n-type conductivity in high-quality InN grown by molecular beam epitaxy. The dislocation densities and H profiles in films with free electron concentrations in the low 10 17 cm - 3 and mid 10 18 cm - 3 range are measured, and analyzed in a comparative manner. It is shown that dislocations alone could not account for the free electron behavior in the InN films. On the other hand, large concentrations of H sufficient to explain, but exceeding substantially, the observed free electron densities are found. Furthermore, enhanced concentrations of H are revealed at the film surfaces, resembling the free electron behavior with surface electron accumulation. The low-conductive film was found to contain C and it is suggested that C passivates the H donors or acts as an acceptor, producing compensated material in this case. Therefore, it is concluded that the unintentional impurities play an important role for the unintentional n-type conductivity in InN. We suggest a scenario of H incorporation in InN that may reconcile the previously reported observations for the different role of impurities and dislocations for the unintentional n-type conductivity in InN.

A method based on focused ion beam milling and analytical electron microscopy to investigate the nature of the tool-chip interface is presented. It is employed to study tool-chip interfaces of the rake face of a (Ti0.83Si0.17)N coated PCBN insert after turning of case-hardened steel. Analytical electron microscopy shows the presence of a smeared adhered layer on the coating, which consists of steel elements from the work-piece, oxygen, and Si and N, most likely originating from the coating. Original Publication:Axel Flink, R M Saoubi, Finn Giuliani, J Sjolen, T Larsson, Per Persson, M P Johansson and Lars Hultman, Microstructural characterization of the tool-chip interface enabled by focused ion beam and analytical electron microscopy, 2009, WEAR, (266), 11-12, 1237-1240.http://dx.doi.org/10.1016/j.wear.2009.03.001Copyright: Elsevier Science B.V., Amsterdam.http://www.elsevier.com/

As a result of progresses in surveillance programs and improvements in diagnosis, an increased number of hepatocellular carcinomas are diagnosed in early stage, when effective treatment options are available. Surgical resection, liver transplantation and radiofrequency ablation are considered potentially curative treatments and may be successfully applied when the disease is limited. In intermediate and advanced stages only palliative therapies can be employed and chemoembolization and the oral dual inhibitor sorafenib are considered the treatments of choice. Future directions will explore the role of sorafenib in the adjuvant setting, the addition of sorafenib to chemoembolization procedures and the combination of sorafenib with chemotherapeutic agents or other biological drugs in advanced stages of disease.

Previous acoustic instrumentation of the SIMPLE detector has relied on the use of a low-cost piezoelectric transducer, which was generally unable to provide discrimination between true bubble nucleation events and ambiental sources of acoustic noise. The use of a high-quality electret microphone and adaptive electronics is shown to provide this capacity through reduced noise levels and distinct fast Fourier transforms of the event registration.

International audience; The application of Superheated Droplet Detectors in dark matter searches by the SIMPLE project uses an acoustic instrumentation sensitive to the shock wave generated by the bubble nucleation of the refrigerant droplets. Previous instrumentation has been unable to distinguish between true nucleation and background noise events in the device, in particular microleaks associated with the escape of overpressuring nitrogen gas into the surrounding water bath. We here describe the development of an improved instrumentation which is shown to provide this discrimination capacity through a reduced noise level of the transducer amplification circuitry. (c) 2007 Elsevier B.V. All rights reserved.

We show that due to the peculiar structure of the non-interacting energy spectrum, the Coulomb interaction leads for all densities to an in-plane ferromagnetic instability in a two-dimensional electron liquid in the presence of sufficiently strong Rashba spin-orbit coupling. This non perturbative phenomenon is characterized by an interesting anisotropic momentum space repopulation and is in nature quite different from the already identified out-of-plane ferromagnetic instability.

We show that a result equivalent to Overhauser’s famous Hartree-Fock instability theorem can be established for the case of a two-dimensional electron gas in the presence of Rashba spin-obit coupling. In this case it is the spatially homogeneous paramagnetic chiral ground state that is shown to be differentially unstable with respect to a certain class of distortions of the spin-density-wave and charge-density-wave type. The result holds for all densities. Basic properties of these inhomogeneous states are analyzed.

Single-crystal NaCl-structure Al0.68Cr0.32N thin films were deposited onto MgO(0 0 1) substrates. The films exhibit cube-on-cube epitaxial growth with an initial pseudomorphic strained layer before ...

It is generally accepted that the hardness of silicon and germanium at low temperature is limited by a phase transformation under the indenter, as the measured hardness is equal to the transformation pressure. However, observations of the deformation under indents using transmission electron microscopy indicate that, in addition to the phase transformation, there is also plastic flow both in the transformed region and outside it. An analysis based on the spherical cavity model for indentation was developed to quantify the effect of a phase transformation on the measured hardness. This predicts that plastic deformation will extend beyond the transformed zone when the transformation pressure is greater than two-thirds of the yield stress. The analysis also predicts that the hardness can only be approximately equal to the transformation pressure if the yield strength of the transformed material is low, consistent with the experimental observations of substantial plastic deformation of the transformed phase, as well as with estimates of its lattice resistance.

The application of Superheated Droplet Detectors (SDDs) to dark matter searches has been confined to the spin-dependent (SD) sector owing to the high content of fluorine of these refrigerants (C 2 ClF 5 , C 4 F 10 , C 3 F 8 , etc.). Given the competitive results of these devices, because of their thermodynamically tunable insensitivity to spurious background particles (μ − , e − ), we examine the potential impact of a heavy SDD loaded with trifluoroiodomethane (CF 3 I) in the spin-independent (SI) sector.

Background: In the absence of accurate data on the free two-body hyperon-nucleon interaction, the spectra of hypernuclei provides information on the details of the effective hyperon-nucleon interaction.Purpose: To obtain a high-resolution binding-energy spectrum for the ${}^{9}\mathrm{Be}(e,{e}^{\ensuremath{'}}{K}^{+})_{\ensuremath{\Lambda}}^{9}\mathrm{Li}$ reaction.Method: Electroproduction of the hypernucleus $_{\ensuremath{\Lambda}}^{9}\mathrm{Li}$ has been studied for the first time with sub-MeV energy resolution in Hall A at Jefferson Lab on a $^{9}\mathrm{Be}$ target. In order to increase the counting rate and to provide unambiguous kaon identification, two superconducting septum magnets and a ring imaging Cherenkov detector were added to the Hall A standard equipment.Results: The cross section to low-lying states of $_{\ensuremath{\Lambda}}^{9}\mathrm{Li}$ is concentrated within 3 MeV of the ground state and can be fit with four peaks. The positions of the doublets agree with theory while a disagreement could exist with respect to the relative strengths of the peaks in the doublets. The $\ensuremath{\Lambda}$ separation energy, ${B}_{\ensuremath{\Lambda}}$, of $8.36\ifmmode\pm\else\textpm\fi{}0.08$ (stat.) $\ifmmode\pm\else\textpm\fi{}0.08$ (syst.) MeV was measured, in agreement with an earlier experiment.

Dedicated high-resolution detectors are required for detection of small cancerous breast tumours by molecular imaging with radionuclides. Absorptive collimation is normally applied in imaging single photon emitters, but it results in a strong reduction in detection efficiency. Systems based on electronic collimation are complex and expensive. For these reasons simulations and measurements have been performed to design optimised dedicated high-resolution mini gamma camera. Critical parameters are contrast and signal-to-noise ratio (SNR). Intrinsic performance (spatial resolution, pixel identification, and response linearity and uniformity) were first optimised. Pixellated scintillator arrays (NaI(Tl)) of different pixel size were coupled to arrays of PSPMTs with different anode pad dimensions (6 6m m 2 and 3 3m m 2 ). Detectors having a field of view (FOV) of 100 100 mm 2 and 150 200 mm 2 were designed and built. The electronic system allows read out of all the anode pad signals. The collimation technique was then considered and limits of coded aperture option were studied. Preliminary results are presented.

This paper reviews how layered interfaces influence the deformation behaviour of thin ceramic films. It is shown that the substantial increases in hardness of approximately 30 GPa that have been reported are not generally observed, and the ideas to explain them, based on changes in dislocation line energy, are inconsistent with these observations. Cross-sectional transmission electron microscopy of TiN/NbN multilayers with wavelengths from 2 to 25 nm shows that flow occurs by dislocation motion across the layers and by the compaction of layers if they are porous. The hardness of the multilayers is approximately 6 GPa greater than that of the monolithic films using a rule of mixtures, whilst there is no significant variation in hardness with layer thickness. It is shown that these observations are significantly closer to the predictions made using analyses based on changes to the dislocation line energy and it is tentatively suggested that the high values previously reported were associated with high internal stresses.

10th International Conference on Radiation Shielding (ICRS-10)/13th ANS Topical Meeting on Radiation Protection and Shielding (RPS 2004), Funchal, PORTUGAL, MAY 09-14, 2004; International audience; SIMPLE is a superheated droplet detector (SDD) experiment designed to search for the evidence of spin-dependent weakly interacting neutralino dark matter (WIMPs). SDDs, a type of emulsion detector, consist of a uniform suspension of superheated liquid droplets in a compliant material such as a polymeric or aqueous gel. We report on the first neutron spectrometry experiments with SIMPLE SDDs, a spin-off of the neutron detector calibrations performed at the Portuguese Research Reactor. SIMPLE SDDs differ from most SDDs available commercially as they have a 10 times higher loading factor, containing 103 times more freon than their commercial counterparts and a 100 times larger volume. We have analysed the response of SIMPLE SDDs to two quasi-monochromatic neutron beams of energies 54 and 144 keV obtained with passive filters. Results show that the characteristic peaks in the fluence distribution of both filters could be determined and their energy position obtained using a simple thermodynamic relation.

Observations elsewhere have shown that multilayer structures with layers ~10 nm thick can be harder than monolithic ones. Here we see whether these effects can be observed at high temperatures and investigate the effect of temperature on the manner of deformation. The hardness of an AlN/CrN multilayer structure with a range of wavelengths from 6-200 nm has been measured at temperatures from room temperature to 400 oC. The changes in hardness have been related to the deformation behaviour observed by cross-sectional transmission electron microscopy and atomic force microscopy. These observations suggest that the mechanical properties of the coatings are dominated by the refinement in the columnar microstructure rather than directly by an effect of the layer interfaces on dislocation motion.

Examination of cross-sections of nanoindents with the transmission electron microscope has recently become feasible owing to the development of focused ion beam milling of site-specific electron transparent foils. Here, we discuss the development of this technique for the examination of nanoindents and survey the deformation behaviour in a range of single crystal materials with differing resistances to dislocation flow. The principal deformation modes we discuss, in addition to dislocation flow, are phase transformation (silicon and germanium), twinning (gallium arsenide and germanium at 400 °C), lattice rotations (spinel), shear (spinel), lattice rotations (copper) and lattice rotations and densification (TiN/NbN multilayers). The magnitude of the lattice rotation, about the normal to the foil, was measured at different positions under the indents. Indents in a partially recrystallized metallic glass Mg 66 Ni 20 Nd 14 were also examined. In this case a low-density porous region was formed at the indent tip and evidence of shear bands was also found. Further understanding of indentation deformation will be possible with three-dimensional characterization coupled with modelling which takes account of the variety of competing deformation mechanisms that can occur in addition to dislocation glide. Mapping the lattice rotations will be a particularly useful way to evaluate models of the deformation process.