12 research outputs found
Design and Testing of a Magnetically Levitated Conveyor
No full textA conveyor device aimed at moving objects placed on a translating chain is studied. Losses, friction and noise reduction are the main objectives, which are obtained by magnetically levitating the chain with the aid of a system of permanent mag-nets placed on the chain and on the beam. A stable vertical levita-tion was obtained, while the horizontal instability was managed reducing the allowed gap between the chain and the beam. A cus-tomized three-phase drive unit was also realized in order to re-duce the size and the inertia of the conveyor. A prototype was built and tested in order to verify the outcomes of the design
Design and testing of a magnetic suspension for a 90° horizontal bend conveyor
No full textPurpose
A conveyor device is studied with the aim to reduce the friction between the inner surface of the beam and the chain. The lower is the friction between the chain and the beam, the lower is the surface wear. The magnetic repulsion force among permanent magnets placed on the beam and on the chain is utilized to reduce friction.
Design/methodology/approach
The considered magnetic suspension is realized with permanent magnets in repulsive configuration; it is designed by solving a constrained optimization problem, with reference to the geometry of the 90° horizontal bend FlexLink WL322 conveyor. Flux density field and its gradient are evaluated using volume integral equation method, allowing to calculate the forces acting on the chain and the stiffness of the magnetic suspension.
Findings
The magnetic suspension prototype was manufactured and tested. The experimental and calculated values of the forces acting on the chain compares well. A stable horizontal equilibrium of the chain was obtained during both static and dynamical tests.
Research limitations
The quasi-static model used neglects the dynamical interactions among the elements of the chain, the permanent magnets and loads weight during motions and the eddy current losses in the aluminium beam. However the dynamical tests on the prototype show that the chain motion is regular up to the nominal velocity all along the conveyor with the exception of the trailing edge of the 90° curve.
Practical implications
The tests on the prototype show the possibility of a removal or at least a reduction of the friction force between the chain and the inner side of the beam by means of a passive magnetic suspension. As a consequence a reduction of noise and vibrations and an increase of the mean-time-to-failure is expected.
Originality/value
Prototype testing shows that the unavoidable vertical instability of the magnetic forces has no practical consequence since, re-ducing the allowed vertical gap, the chain is stabilized by the gravitational force
Passi nel passato. Le pratiche rituali ipogee mesoamericane come forma di interazione con il passato
No full textIl contributo propone una nuova interpretazione di alcune maschere lignee rinvenute in grotte messicane, intendendole come parti di involti rituali piuttosto che come maschere funerarie. Tali involti sarebbero stati legati al culto ipogeo degli nuhu, entità extraumane legate al paesaggio e protagoniste di un mito d'origine mixteco attestato in codici pittografici preispanici, in fonti alfabetiche del XVI secolo e in resoconti etnografici del XX secolo. Sulla base della proposta avanzata, si definiscono i culti ipogei mesoamericani come forme di partecipazione al passato mitico e quindi come pratiche inscrivibili in quella che sulla scorta di Tim Ingold si può definire come dimensione temporale del paesaggio
Author correction: obesity and ethnicity alter gene expression in skin
No full textDaniel Butler was omitted from the author list in the original version of this Article. The Author contributions section now reads: “J.M.W. designed, conducted, and contributed to the writing of the manuscript, prepared Fig. 1. S.G. evaluated and did statistical analysis on the skin and fat samples, prepared Figs. 2–9. J.O.A. evaluated and contributed to writing the manuscript. D.B prepared and sequenced DNA libraries for the skin microbiota data, and wrote the applicable parts of the methods section. C.M. analyzed and wrote up the skin microbiota data, prepared Fig. 10. All authors have read the manuscript and approved its contents. D.D. analyzed and wrote up the skin microbiota data. S.Z. ran and analyzed the skin metabolite data. J.S. assisted in design, analysis and wrote up the skin metabolite data. J.K. assisted in analysis write up of skin and fat data. J.L.B. assisted in analysis, interpretation and writing of the manuscript. P.R.H. designed, analyzed, interpreted the data, and was the primary author of the manuscript.” This has been corrected in the PDF and HTML versions of the Article, and in the accompanying Supplementary Information file.</p
Heterogeneous distribution of calcite cement at the outcrop scale in Tertiary sandstones, northern Apennines, Italy
No full textCalcite cement derived intraformationally in seven stratigraphic units of marine origin is distributed heterogeneously at the outcrop scale. Sandstone beds intercalated with calcareous shale older than Pliocene tend to be completely cemented, whereas stacked sandstone beds that lack shale interbeds have calcite cement in the form of tightly cemented concretions that make up only 10-30% of a bed. Patterns of concretions within beds are remarkably varied and include both random and uniform spacing. There is no preference of concretions for shell-rich layers. The lack of strong textural or compositional controls on the localization of calcite cement suggests the preeminence of highly localized hydrologic factors in determining the spatial distribution of authigenic pore-filling calcite. Faults apparently served as fluid conduits and were selectively cemented. In general, only sandstones intercalated with shale are totally cemented. -from Author
Gene expression profile predicts response to the combination of tosedostat and low-dose cytarabine in elderly AML
No full textTosedostat is an orally administered metalloenzyme inhibitor with antiproliferative and antiangiogenic activity against hematological and solid human cancers. Clinical activity has been demonstrated in relapsed acute myeloid leukemia (AML). Thirty-three elderly patients with AML (median age, 75 years) received 120 mg tosedostat orally once daily combined with subcutaneous low-dose cytarabine (20 mg twice per day for 10 days, up to 8 cycles), until disease progression. Induction mortality was 12%. According to an intention-to-treat analysis, the complete remission (CR) rate was 48.5%, and thus the primary end point of the study was reached (expected CR, 25%). The partial remission rate was 6.1%, with an overall response rate of 54.5%. Furthermore, 4 of 33 patients had stable disease (median: 286 days). The median progression-free survival and overall survival (OS) were 203 days and 222 days, respectively. Responding patients had a longer median OS than nonresponding patients (P = .001). A microarray analysis performed in 29 of 33 patients identified 188 genes associated with clinical response (CR vs no CR). Three of them (CD93, GORASP1, CXCL16) were validated by quantitative polymerase chain reaction, which correctly classified 83% of the patients. Specifically, CR achievement was efficiently predicted by the gene expression patterns, with an overall accuracy exceeding 90%. Finally, a negative predictive value of 100% was validated in an independent series, thus representing the first molecular predictor for clinical response to a specific combination drug treatment for AML. This trial has been registered at the European Medicines Agency and on the European Clinical Trials Database (https://www.clinicaltrialsregister.eu) as #2012-000334-19
