Multiphase flow metering with operationally robust, low-cost real-time systems that provide accuracy across a broad range of produced volumes and fluid properties, is a requirement across a range of ...process industries, particularly those concerning petroleum. Especially the wide variety of multiphase flow profiles that can be encountered in the field provides challenges in terms of metering accuracy. Recently, low-field magnetic resonance (MR) measurement technology has been introduced as a feasible solution for the petroleum industry. In this work, we study two phase air-water horizontal flows using MR technology. We show that low-field MR technology applied to multiphase flow has the capability to measure the instantaneous liquid holdup and liquid flow velocity using a constant gradient low flip angle CPMG (LFA-CPMG) pulse sequence. LFA-CPMG allows representative sampling of the correlations between liquid holdup and liquid flow velocity, which allows multiphase flow profiles to be characterized. Flow measurements based on this method allow liquid flow rate determination with an accuracy that is independent of the multiphase flow profile observed in horizontal pipe flow for a wide dynamic range in terms of the average gas and liquid flow rates.
We have used low-field (1)H nuclear-magnetic resonance (NMR) spectroscopy and molecular dynamics (MD) to investigate the aggregation dynamics of magnetic particles in ionic ferrofluids (IFFs) in the ...presence of magnetic field gradients. At the beginning of the experiments, the measured NMR spectra were broad and asymmetric, exhibiting two features attributed to different dynamical environments of water protons, depending on the local strength of the field gradients. Hence, the spatial redistribution of the magnetic particles in the ferrofluid caused by the presence of an external magnetic field in a time scale of minutes can be monitored in real time, following the changes in the features of the NMR spectra during a period of about an hour. As previously reported Heinrich et al., Phys. Rev. Lett., 2011, 106, 208301, in the homogeneous magnetic field of a NMR spectrometer, the aggregation of the particles of the IFF proceeds in two stages. The first stage corresponds to the gradual aggregation of monomers prior to and during the formation of chain-like structures. The second stage proceeds after the chains have reached a critical average length, favoring lateral association of the strings into hexagonal zipped-chain superstructures or bundles. In this work, we focus on the influence of a strongly inhomogeneous magnetic field on the aforementioned aggregation dynamics. The main observation is that, as the sample is immersed in a certain magnetic field gradient and kept there for a time τinh, magnetophoresis rapidly converts the ferrofluid into an aggregation state which finds its correspondence to a state on the evolution curve of the pristine sample in a homogeneous field. From the degree of aggregation reached at the time τinh, the IFF sample just evolves thereafter in the homogeneous field of the NMR spectrometer in exactly the same way as the pristine sample. The final equilibrium state always consists of a colloidal suspension of zipped-chain bundles with the chain axes aligned along the magnetic field direction.
Combining nuclear magnetic resonance and molecular dynamics simulations, we unravel the long-time dynamics of a paradigmatic colloid with strong dipole-dipole interactions. In a homogeneous magnetic ...field, ionic ferrofluids exhibit a stepwise association process from ensembles of monomers over stringlike chains to bundles of hexagonal zipped-chain patches. We demonstrate that attractive van der Waals interactions due to charge-density fluctuations in the magnetic particles play the key role for the dynamical stabilization of the hexagonal superstructures against thermal dissociation. Our results give insight into the dynamics of self-organization in systems dominated by dipolar interactions.
UV-B radiation (UVBR) is a small fraction of the solar spectrum from 280 to 315nm. UVBR produces photomorphogenic acclimation responses in plants, modulating their cellular structure and physiology. ...Here, changes in the peel of harvested lemons after short time exposure to UVBR were analyzed and its potential effects against fungal infection were studied. In the flavedo, UVBR treatment induced variations in the respiratory profiles and increased the phenolic compound contents. Final products of the flavonoid pathway (flavones, flavonols and anthocyanins) increased more markedly than their precursors (flavanones and dihydroflavonols). The increased accumulation of soluble phenolics in the flavedo of treated lemons is associated with the high antioxidant activity found in the flavedo of these samples. Supporting the biochemical determinations, anatomical observations showed abundant intravacuolar deposits of phenolic compounds and an increase in the cell wall thickness in UVBR-treated samples. Metabolic and anatomical modifications associated to UVBR improved natural defenses against Penicillium digitatum, the causal agent of green mold disease. Our results suggest that mature postharvest lemons exposed to the artificial radiation showed phenotypic plasticity, allowing an acclimation response to UVBR which confers fruit resistance to pathogens. Thus, combination of UVBR with other treatments could represent an important improvement to control postharvest diseases on citrus.
•UV-B radiation (UVBR) induced metabolic and anatomical changes on postharvest lemons.•Metabolic and anatomical changes induced by UVBR increase the fruit natural defenses.•Enhanced natural defenses contribute to reduce green mold incidence.
The objective of the MAPPING study was to estimate the prevalence of musculoskeletal conditions in an Italian population sample.
Questionnaires were sent to a random sample of 3664 individuals aged ...18 years and over, stratified for age and gender, selected from the practice lists of 16 general practices. Trained rheumatologists carried out structured visits in which subjects were asked about musculoskeletal symptoms and socio-demographic characteristics, and underwent a standardized physical examination. Cases were defined by previously validated criteria.
A total of 2155 subjects participated in the study (response rate 58.8%). The overall prevalence of musculoskeletal conditions in the general adult population was 26.7% (95% CI 25.4-28.5), being significantly higher among women than men (p < 0.0001). Disease prevalence increased significantly with age (p < 0.0001). The most common disease group was symptomatic peripheral osteoarthritis (SPOA), with a prevalence of 8.95% (95% CI 6.81-10.7), followed by soft tissue disorders--STD (8.81%; 95% CI 7.16-10.29), low back pain--LBP (5.91%; 95% CI 4.89-6.89), and inflammatory rheumatic disease--IRD (3.06%; 95% CI 2.38-3.93). The estimated rates of disease prevalence were as follows: rheumatoid arthritis: 0.46% (95% CI 0.33-0.59); psoriatic arthritis: 0.42% (95% CI 0.31-0.61); ankylosing spondylitis: 0.37% (95% CI 0.23-0.49); polymyalgia rheumatica: 0.37% (95% CI 0.29-0.44); undifferentiated connective tissue disease: 0.14% (95% CI 0.09-0.21); crystal arthropathies, including gout 0.46% (95% CI 0.34-0.57) and chondrocalcinosis: 0.42% (95% CI 0.33-0.58); symptomatic knee osteoarthritis (OA): 5.39% (95% CI 3.41-7.99); hip-OA: 1.61% (95% CI 1.39-1.87); hand-OA: 1.95 (95% CI 1.22-2.48); fibromyalgia: 2.22% (95% CI 1.36-3.19); shoulder tendinitis/adhesive capsulitis: 3.06% (95% CI 2.11-4.09); carpal tunnel syndrome: 1.90% (95% CI 1.06-2.29), localized regional pain syndromes of the neck: 0.88% (95% CI 0.561.29), and lateral epicondylitis 0.74% (95% CI 0.47-1.33).
The MAPPING study indicates that musculoskeletal conditions are common in the general adult population of Italy. These data are useful in planning the provision of healthcare.
Background/Aims: Lamivudine therapy in patients with chronic hepatitis B can induce the recovery of antiviral T cell responses. It is unknown whether the recovery of T cell responsiveness is ...long-lasting and persists throughout the treatment and whether the elevation of viremia which follows therapy withdrawal can restore a condition of T cell unresponsiveness.
Methods: Frequency and function of circulating hepatitis B virus (HBV)-specific CD4 and CD8 cells from 12 hepatitis e surface antigen + patients with chronic hepatitis B were studied longitudinally before, during and after lamivudine therapy by intracellular cytokine staining, proliferation and cytotoxicity assays against HBV proteins and peptides. CD4-mediated responses were analyzed in all patients, whereas CD8 cells were studied in 6 HLA-A2+ patients.
Results: HBV-specific CD4 and CD8 reactivity showed a bi-phasic behavior under lamivudine therapy with an early enhancement of T cell frequency and intensity of responses followed by a persistent decline starting from the 5th to 6th month of treatment.
Conclusions: Since restoration of HBV-specific T cell reactivity is only transient, our study indicates that therapeutic stimulation of HBV-specific T cell responses to complement lamivudine treatment should be done early after the initiation of lamivudine. Moreover, the transient nature of the immune reconstitution may represent a favorable condition for virus reactivation once lamivudine therapy is withdrawn.
Status of the cylindrical-GEM project for the KLOE-2 inner tracker Balla, A.; Bencivenni, G.; Cerioni, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2011, Letnik:
628, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The status of the R&D on the Cylindrical-GEM (CGEM) detector foreseen as inner tracker for KLOE-2, the upgrade of the KLOE experiment at the
DA
Φ
NE
φ
-factory
, is presented. The R&D includes ...several activities: (i) the construction and complete characterization of the full-size CGEM prototype, equipped with
650
μ
m
pitch 1-D longitudinal strips; (ii) the study of the 2-D readout with XV patterned strips and operation in magnetic field (up to 1.5
T), performed with small planar prototypes in a dedicated test at the H4-SPS beam facility; (iii) the characterization of the single-mask GEM technology for the realization of large-area GEM foils.
Micro Pattern Gas Detectors (MPGD) are the new frontier in gas trackers. Among this kind of devices, the Gas Electron Multiplier (GEM) chambers are widely used. The experimental signals acquired with ...the detector must obviously be reconstructed and analysed. In this contribution, a new offline software to perform reconstruction, alignment and analysis on the data collected with APV-25 and TIGER ASICs will be presented. GRAAL (Gem Reconstruction And Analysis Library) is able to measure the performance of a MPGD detector with a strip segmented anode (presently). The code is divided in three parts: reconstruction, where the hits are digitized and clusterized; tracking, where a procedure fits the points from the tracking system and uses that information to align the chamber with rotations and shifts; analysis, where the performance is evaluated (e.g. efficiency, spatial resolution,etc.). The user must set the geometry of the setup and then the program returns automatically the analysis results, taking care of different conditions of gas mixture, electric field, magnetic field, geometries, strip orientation, dead strip, misalignment and many others.
PDF
