216 research outputs found
Non-magnetic Anomaly at 1K Arising in Ferromagnetic Ce2.15(Pd1-xAgx)1.95In0.9
Magnetic and thermal properties of Ferromagnetic (FM) Ce2.15(Pd1-xAgx)1.95In0.9 alloys were studied in order to determine the Quantum Critical Point (QCP) at TC \u2192 0. The in- crease of band electrons produced by Pd/Ag substitution depresses TC (x) from 4.1K down to TC (x = 0.5)=1.1K, with a QCP extrapolated to xQCP 65 0.5. Magnetic susceptibility from T > 30K indicates an effective moment slightly decreasing from \u3bceff =2.56\u3bcB to 2.4\u3bcB at x=0.5. These values and the paramagnetic temperature \u3b8P 48 -10K exclude significant Kondo screening effects. The TC (x) reduction is accompanied by a weakening of the FM magnetization and the emergence of a specific heat Cm(T) anomaly at T 17 48 1K, without signs of magnetism detected from AC-susceptibility. The magnetic entropy collected around 4K (i.e. the TC of the x = 0 sample) practically does not change with Ag concentration: Sm(4K) 48 0.8 Rln2, suggesting a progressive transfer of FM degrees of freedom to the non-magnetic (NM) compo- nent. No antecedent was found concerning any NM anomaly emerging from a FM system at such temperature. The origin of this anomaly is attributed to an entropy bottleneck originated in the nearly divergent power law dependence for T > T 17
Shop Full-Load Testing Of Centrifugal Compressors
PaperPg. 113-120.The high reliability traditionally required of turbocompressors has become even more imperative in recent years, due to increased unit power and the extreme environmental conditions of many applications. These machines are now often used in highly demanding compression service, such as reinjection and sea pipelines. In these applications there have been, unfortunately, some examples of malfunctioning. As a result, machines are often requested to undergo all possible testing before leaving the factory. Full-load tests are now being requested in addition to the more traditional no-load mechanical and performance tests. In the field of natural gas machinery, full-load tests were initially performed mainly for the purpose of verifying the rotor-dynamic stability of compressors at high pressure, as well as their overall performance. Subsequently, full-load testing of the complete compression system (driver, coupling and gear, lube and seal oil systems, control system, coolers, etc.) was performed. Finally, testing was carried out on the entire module
Improving Knot Segmentation Using Deep Learning Techniques
In the context of Computed Tomography scanning of logs, accurate detection of knots is key for
delivering a successful product. Reliable detection of knots in the sapwood is hard with traditional
computer vision techniques, because of the different density conditions between sapwood and
heartwood. The advancements provided by deep learning in the field of semantic image segmentation
kick-started a new way of approaching such problems: deep neural networks can be trained on large
amounts of labelled data and successfully employed in production environments to improve the
performances on knot detection. Adapting state-of-the-art network architectures and using more than
10.000 labelled knots from pine and spruce logs, we were able to develop a new two-step approach for
identifying knots in CT scans of logs with unprecedented accuracy while at the same time satisfying
the time constraints that a real-time industrial application needs. The first step runs on the logâs axis,
while the second runs on each candidate knotâs axis. False positives from the first step are very rare
(even with dry/dried logs), so no computational power is wasted for non-existing knots. Using this
approach, we are able to see the internal defects of a log in real time in the production chain without
having to cut it first, therefore being able to optimize even more the output of the chain on each
clientâs requirements
Brucella abortus Strain RB51 Vaccine: Immune Response after Calfhood Vaccination and Field Investigation in Italian Cattle Population
Immune response to Brucella abortus strain RB51 vaccine was measured in cattle vaccinated at calfhood. After an increase at day 6 post-vaccination (pv), the antibody level recorded in the 10 vaccinated animals remained constant for two months, and then progressively decreased. All vaccinated animals remained negative from day 162âpv to the end of the study (day 300âpv). Only at days 13 and 14âpv the RB51-CFT showed 100% sensitivity (credibility interval (CI) 76.2%â100%). The results indicate that the possibility to use RB51-CFT for the identification of cattle vaccinated at calfhood with RB51 is limited in time. A field investigation was carried out on 26,975 sera collected on regional basis from the Italian cattle population. The study outcomes indicate that in case of RB51-CFT positive results observed in officially Brucellosis-free (OBF) areas and, in any case, when an illegal use of RB51 vaccine is suspected, the use of the RB51-CFT alone is not sufficient to identify all the vaccinated animals. The design of a more sophisticated diagnostic protocol including an epidemiological investigation, the use of RB51-CFT, and the use of the skin test with RB51 as antigen is deemed more appropriate for the identification of RB51 vaccinated animals
Structural and Magnetic Properties of Yb0.5Ce0.5Ni5
The rare-earth magnetism in the intermetallic compound Yb0.5Ce0.5Ni5 was studied using X-ray diffraction, magnetization, heat capacity, and electrical resistivity measurements. The effect of spin fluctuations (SF) was observed in M(T) at ~40 K. The measurement of thermal and transport properties supported the results obtained from magnetic measurements. Collected experimental data showed that Yb/Ce substitution shifts the maximum temperature for spin fluctuations to a lower temperature compared to that for pure CeNi5. Moreover, at low temperatures, an anomaly in the heat capacity of possible magnetic origin arising from Yb3+ was detected. Ce atoms seemed to remain in a non-magnetic valence state at almost 4+.This research was funded by the Slovak Grant Agency VEGA 1/0404/21 (Materials with emergent behaviour and application possibilities under extreme physical conditions influence); VEGA 1/0705/20 (Novel rare earth based intermetallic compounds - crystal structure and physical properties of their ground state); VEGA 1/0053/19 (Influence of chemical composition on unique physical properties of modern functional materials) and APVV-16-0079 (Modern amorphous and polycrystalline functional materials for sensors and actuators
Hard X-ray emission from the galaxy cluster A3667
We report the results of a long BeppoSAX observation of Abell 3667, one of
the most spectacular galaxy cluster in the southern sky. A clear detection of
hard X-ray radiation up to ~ 35 keV is reported, while a hard excess above the
thermal gas emission is present at a marginal level that should be considered
as an upper limit to the presence of nonthermal radiation. The strong hard
excesses reported by BeppoSAX in Coma and A2256 and the only marginal detection
of nonthermal emission in A3667 can be explained in the framework of the
inverse Compton model. We argue that the nonthermal X-ray detections in the PDS
energy range are related to the radio index structure of halos and relics
present in the observed clusters of galaxie.Comment: 15 pages, 1 figure, ApJL in pres
The Current State of Validation of Administrative Healthcare Databases in Italy: A Systematic Review
Background: Administrative healthcare databases are widely present in Italy. Our aim was to describe the current state of healthcare databases validity in terms of discharge diagnoses (according to the International Classification of Diseases, ICD-9 code) and their output in terms of research.Methods: A systematic search of electronic databases including Medline and Embase (1995-2013) and of local sources was performed. Inclusion criteria were: healthcare databases in any Italian territory routinely and passively collecting data; medical investigations or procedures at patient level data; the use of a validation process. The quality of studies was evaluated using the STARD criteria. Citations of the included studies were explored using Scopus and Google Scholar.Results: The search strategy allowed the identification of 16 studies of which 3 were in Italian. Thirteen studies used regional administrative databases from Lombardia, Piemonte, Lazio, Friuli-Venezia Giulia and Veneto. The ICD-9 codes of the following diseases were successfully validated: amyotrophic lateral sclerosis (3 studies in four different regional administrative databases), stroke (3 studies), gastrointestinal bleeding (1 study), thrombocytopenia (1 study), epilepsy (1 study), infection (1 study), chronic obstructive pulmonary disease (1 study), Guillain-Barre syndrome (1 study), and cancer diseases (4 studies). The quality of reporting was variable among the studies. Only 6 administrative databases produced further research related to the validated ICD-9 codes.Conclusion: Administrative healthcare databases in Italy need an extensive process of validation for multiple diagnostic codes to perform high quality epidemiological and health services research
Diverse plant promoting bacterial species differentially improve tomato plant fitness under water stress
IntroductionFood crops are increasingly susceptible to the challenging impacts of climate change, encompassing both abiotic and biotic stresses, that cause yield losses. Root-associated microorganisms, including plant growth-promoting bacteria (PGPB), can improve plant growth as well as plant tolerance to environmental stresses. The aims of this work were to characterize bacteria isolated from soil and roots of tomato plants grown in open field.MethodsBiochemical and molecular analyses were used to evaluate the PGP potential of the considered strains on tomato plants in controlled conditions, also assessing their effects under a water deficit condition. The isolated strains were classified by 16S gene sequencing and exhibited typical features of PGPB, such as the release of siderophores, the production of proteases, and phosphorous solubilization. Inoculating tomato plants with eleven selected strains led to the identification of potentially interesting strains that increased shoot height and dry weight. Three strains were then selected for the experiment under water deficit in controlled conditions. The tomato plants were monitored from biometric and physiological point of view, and the effect of inoculation at molecular level was verified with a targeted RT-qPCR based approach on genes that play a role under water deficit condition.ResultsResults revealed the PGP potential of different bacterial isolates in tomato plants, both in well-watered and stressed conditions. The used integrated approach allowed to obtain a broader picture of the plant status, from biometric, eco-physiological and molecular point of view. Gene expression analysis showed a different regulation of genes involved in pathways related to abscisic acid, osmoprotectant compounds and heat shock proteins, depending on the treatments. DiscussionOverall, results showed significant changes in tomato plants due to the bacterial inoculation, also under water deficit, that hold promise for future field applications of these bacterial strains, suggesting that a synergistic and complementary interaction between diverse PGPB is an important point to be considered for their exploitation
Pressure-induced anomalous valence crossover in cubic YbCu5-based compounds
A pressure-induced anomalous valence crossover without structural phase transition is observed in archetypal cubic YbCu5 based heavy Fermion systems. The Yb valence is found to decrease with increasing pressure, indicating a pressure-induced crossover from a localized 4f (13) state to the valence fluctuation regime, which is not expected for Yb systems with conventional c-f hybridization. This result further highlights the remarkable singularity of the valence behavior in compressed YbCu5-based compounds. The intermetallics Yb2Pd2Sn, which shows two quantum critical points (QCP) under pressure and has been proposed as a potential candidate for a reentrant Yb(2+) state at high pressure, was also studied for comparison. In this compound, the Yb valence monotonically increases with pressure, disproving a scenario of a reentrant non-magnetic Yb(2+) state at the second QCP
Prevention of food and airway allergy : Consensus of the Italian Society of Preventive and Social Paediatrics, the Italian Society of Paediatric Allergy and Immunology, and Italian Society of Pediatrics
Background: Allergic sensitization in children and allergic diseases arising therefrom are increasing for decades. Several interventions, functional foods, pro- and prebiotics, vitamins are proposed for the prevention of allergies and they can't be uncritically adopted. Objective: This Consensus document was developed by the Italian Society of Preventive and Social Paediatrics and the Italian Society of Paediatric Allergy and Immunology. The aim is to provide updated recommendations regarding allergy prevention in children. Methods: The document has been issued by a multidisciplinary expert panel and it is intended to be mainly directed to primary care paediatricians. It includes 19 questions which have been preliminarily considered relevant by the panel. Relatively to each question, a literature search has been performed, according to the Italian National Guideline Program. Methodology, and a brief summary of the available literature data, has been provided. Many topics have been analyzed including the role of mother's diet restriction, use of breast/formula/hydrolyzed milk; timing of introduction of complementary foods, role (if any) of probiotics, prebiotics, vitamins, exposure to dust mites, animals and to tobacco smoke. Results: Some preventive interventions have a strong level of recommendation. (e.g., the dehumidifier to reduce exposure to mite allergens). With regard to other types of intervention, such as the use of partially and extensively hydrolyzed formulas, the document underlines the lack of evidence of effectiveness. No preventive effect of dietary supplementation with polyunsaturated fatty acids, vitamins or minerals has been demonstrated. There is no preventive effect of probiotics on asthma, rhinitis and allergic diseases. It has demonstrated a modest effect, but steady, in the prevention of atopic dermatitis. Conclusions: The recommendations of the Consensus are based on a careful analysis of the evidence available. The lack of evidence of efficacy does not necessarily imply that some interventions may not be effective, but currently they can't be recommended
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