Using engineered composite materials in sealless magnetic drive pumps to eliminate eddy currents and improve reliability

Case StudyBackground - Pump application: This case study is based on an application supplied into a Polysilicon production facility. The purpose of the application is to pump Trichlorosilane (TCS) liquid into the production process which allows the Polysilicon crystals to grow within a reactor. The pumps were API 685 2nd edition compliant (parallel standard to API 610) and supplied with a secondary containment system per API 685 para 4.6.2.2. The pumps duty conditions were 217.5m^3/Hr @ 120.5m (955 uspgm @ 395 Feet) and operating at rotational speed of 3500rpm with a 185kW (250 Hp)

Experimental and Numerical Studies of Mode I and Mode II Delamination of Polymer Composites with Embedded Optical Sensors

Over the past decades the use of composite materials has enormously increased, especially in the aeronautical, automotive, and energy production industries. These materials allow to build lighter and larger structures which are more efficient. However, by introducing composite materials into load bearing structures, new modes of failure have to be understood to further improve design and guarantee the safety during the whole life time of such parts. Since composite materials are often produced in layered structures, they are prone to delamination where a crack propagates between the layers. The mechanical tests which are used today to measure the fracture properties cannot account for all processes associated with delamination. Namely, intact fibres that link the fracture surfaces, so called bridging fibres, can strongly influence the outcome of such tests, however, they cannot be quantitatively measured. In this work, a semi-experimental method was developed and used to study delamination tests and identify the contribution of bridging to toughness. For this, the strain distribution around the crack tip was measured with embedded optical sensors, so called fibre Bragg gratings (FBG). A new methodology based on multiplexed FBGs was developed and allowed to acquire a quasi-continuous strain distribution at relatively high rates. The results were then used in an inverse identification method to determine parameters which characterise delamination and bridging. Mode I delamination was studied with the double cantilever beam test in monotonic and fatigue loading. Using the above mentioned method the closing tractions due to bridging fibres were identified and their contribution to the resistance against crack propagation was determined. Compared to the monotonic loading, the contribution of bridging in fatigue was found to be about 30% higher. With a cohesive zone finite element model which was accounting for the bridging tractions, the onset and propagation of the delamination were correctly predicted. The bridging was found to contribute by 50% to the total energy release rate (ERR). In a similar way mode II delamination was studied with a four point end notched flexure test and the ERR as well as friction coefficients were identified using the measured strain distribution. While bridging was found negligible, the ERR in mode II was three times higher than the initiation value of mode I delamination. Finally, in a mixed mode bending test the modes I and II were combined so that each one was contributing by 50% to the delamination. The initiation value was found to be about 15% higher than the one of mode I, although with a large scatter, while the propagation value was only marginally higher. The fibre bridging, which formed during the delamination, was characterised from the changes of strain measured with the embedded optical sensors. The proposed method of strain measurements with embedded optical sensors and inverse identification offers an interesting alternative to existing methods used to characterise delamination. It was successfully used to identify fibre bridging without assumptions on the length of the bridging zone and opens a new way to study micromechanics of fracture in laminated materials

Influence of process pressure on local facesheet instability for ultralight sandwich structures

The skin wrinkling phenomenon was investigated in the case of ultra-light sandwich structures with a honeycomb core manufactured by one-shot vacuum bag processing. The interplay between process pressure and compressive strength of the skin was established. It was observed that the size of the adhesive menisci between honeycomb cell walls and skin, and the waviness of the skin increased with process pressure. As these two effects exerted opposing influences on the compressive strength of the skin, an optimal process pressure equal to 0.7 bar was identified experimentally and confirmed by an analytical model

Unlocking Accuracy and Fairness in Differentially Private Image Classification

Privacy-preserving machine learning aims to train models on private data without leaking sensitive information. Differential privacy (DP) is considered the gold standard framework for privacy-preserving training, as it provides formal privacy guarantees. However, compared to their non-private counterparts, models trained with DP often have significantly reduced accuracy. Private classifiers are also believed to exhibit larger performance disparities across subpopulations, raising fairness concerns. The poor performance of classifiers trained with DP has prevented the widespread adoption of privacy preserving machine learning in industry. Here we show that pre-trained foundation models fine-tuned with DP can achieve similar accuracy to non-private classifiers, even in the presence of significant distribution shifts between pre-training data and downstream tasks. We achieve private accuracies within a few percent of the non-private state of the art across four datasets, including two medical imaging benchmarks. Furthermore, our private medical classifiers do not exhibit larger performance disparities across demographic groups than non-private models. This milestone to make DP training a practical and reliable technology has the potential to widely enable machine learning practitioners to train safely on sensitive datasets while protecting individuals' privacy

Can improved canopy light transmission ameliorate loss of photosynthetic efficiency in the shade An investigation of natural variation in Sorghum bicolor

Previous studies have found that maximum quantum yield of CO2 assimilation (φCO2,max,app) declines in lower canopies of maize and miscanthus, a maladaptive response to self-shading. These observations were limited to single genotypes, leaving it unclear whether the maladaptive shade response is a general property of this C4 grass tribe, the Andropogoneae. We explored the generality of this maladaptation by testing the hypothesis that erect leaf forms (erectophiles), which allow more light into the lower canopy, suffer less of a decline in photosynthetic efficiency than drooping leaf (planophile) forms. On average, φCO2,max,app declined 27% in lower canopy leaves across 35 accessions, but the decline was over twice as great in planophiles than in erectophiles. The loss of photosynthetic efficiency involved a decoupling between electron transport and assimilation. This was not associated with increased bundle sheath leakage, based on 13C measurements. In both planophiles and erectophiles, shaded leaves had greater leaf absorptivity and lower activities of key C4 enzymes than sun leaves. The erectophile form is considered more productive because it allows a more effective distribution of light through the canopy to support photosynthesis. We show that in sorghum, it provides a second benefit, maintenance of higher φCO2,max,app to support efficient use of that light resource

Investigating Protostellar Accretion-Driven Outflows Across the Mass Spectrum: JWST NIRSpec IFU 3-5~μ\mum Spectral Mapping of Five Young Protostars

Investigating Protostellar Accretion (IPA) is a Cycle 1 JWST program using the NIRSpec+MIRI IFUs to obtain 2.9--28 $\mu$m spectral cubes of five young protostars with luminosities of 0.2 to 10,000 L$_{\odot}$ in their primary accretion phase. This paper introduces the NIRSpec 2.9--5.3 $\mu$m data of the inner 840-9000 au with spatial resolutions from 28-300 au. The spectra show rising continuum emission, deep ice absorption, emission from H$_{2}$, H~I, and [Fe~II], and the CO fundamental series in emission and absorption. Maps of the continuum emission show scattered light cavities for all five protostars. In the cavities, collimated jets are detected in [Fe~II] for the four $< 320$~L$_{\odot}$ protostars, two of which are additionally traced in Br-$\alpha$. Knots of [Fe~II] emission are detected toward the most luminous protostar, and knots of [FeII] emission with dynamical times of $< 30$~yrs are found in the jets of the others. While only one jet is traced in H$_2$, knots of H$_2$ and CO are detected in the jets of four protostars. H$_2$ is seen extending through the cavities showing they are filled by warm molecular gas. Bright H$_2$ emission is seen along the walls of a single cavity, while in three cavities, narrow shells of H$_2$ emission are found, one of which has an [Fe~II] knot at its apex. These data show cavities containing collimated jets traced in atomic/ionic gas surrounded by warm molecular gas in a wide-angle wind and/or gas accelerated by bow shocks in the jets.Comment: 30 pages, 11 figure

Extension of HOPS out to 500 pc (eHOPS). I. Identification and Modeling of Protostars in the Aquila Molecular Clouds

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.We present a Spitzer/Herschel focused survey of the Aquila molecular clouds (d ∼ 436 pc) as part of the eHOPS (extension of the Herschel orion protostar survey, or HOPS, Out to 500 ParSecs) census of nearby protostars. For every source detected in the Herschel/PACS bands, the eHOPS-Aquila catalog contains 1–850 μm SEDs assembled from the Two Micron All Sky Survey, Spitzer, Herschel, the Wide-field Infrared Survey Explorer, and James Clerk Maxwell Telescope/SCUBA-2 data. Using a newly developed set of criteria, we classify objects by their SEDs as protostars, pre-main-sequence stars with disks, and galaxies. A total of 172 protostars are found in Aquila, tightly concentrated in the molecular filaments that thread the clouds. Of these, 71 (42%) are Class 0 protostars, 54 (31%) are Class I protostars, 43 (25%) are flat-spectrum protostars, and four (2%) are Class II sources. Ten of the Class 0 protostars are young PACS bright red sources similar to those discovered in Orion. We compare the SEDs to a grid of radiative transfer models to constrain the luminosities, envelope densities, and envelope masses of the protostars. A comparison of the eHOPS-Aquila to the HOPS protostars in Orion finds that the protostellar luminosity functions in the two star-forming regions are statistically indistinguishable, the bolometric temperatures/envelope masses of eHOPS-Aquila protostars are shifted to cooler temperatures/higher masses, and the eHOPS-Aquila protostars do not show the decline in luminosity with evolution found in Orion. We briefly discuss whether these differences are due to biases between the samples, diverging star formation histories, or the influence of environment on protostellar evolution. © 2023. The Author(s). Published by the American Astronomical Society.R.P., S.T.M., and S.A.F. gratefully acknowledge the funding support for this work from the NASA/ADAP grants 80NSSC18K1564 and 80NSSC20K0454. S.T.M. and R.P. also acknowledge funding support from the NSF AST grant 2107827. R.A.G. acknowledges funding from the NASA/ADAP grant NNX17AF24G and the NSF AST grant 2107705. A.S. gratefully acknowledges support by the Fondecyt Regular (project code 1220610), and ANID BASAL projects ACE210002 and FB210003. M.O. acknowledges support from the MCIN/AEI/10.13039/ 501100011033 through the PID2020-114461GB-I00, and the Consejería de Transformación Económica, Industria, Conocimiento y Universidades of the Junta de Andalucía, and the European Regional Development Fund from the European Union through the grant P20-00880. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory (JPL), California Institute of Technology (Caltech), under a contract with NASA; it is also based on observations made with the Herschel Space Observatory, a European Space Agency Cornerstone Mission with significant participation by NASA. The Herschel spacecraft was designed, built, tested, and launched under a contract to ESA managed by the Herschel/Planck Project team by an industrial consortium under the overall responsibility of the prime contractor Thales Alenia Space (Cannes), and including Astrium (Friedrichshafen) responsible for the payload module and for system testing at the spacecraft level, Thales Alenia Space (Turin) responsible for the service module and Astrium (Toulouse) is responsible for the telescope, with more than 100 subcontractors. The James Clerk Maxwell Telescope is operated by the East Asian Observatory on behalf of The National Astronomical Observatory of Japan; Academia Sinica Institute of Astronomy and Astrophysics; the Korea Astronomy and Space Science Institute; the National Astronomical Research Institute of Thailand; Center for Astronomical Mega-Science (as well as the National Key R&D Program of China with No. 2017YFA0402700). Additional funding support is provided by the Science and Technology Facilities Council of the United Kingdom and participating universities and organizations in the United Kingdom and Canada. Additional funds for the construction of SCUBA-2 were provided by the Canada Foundation for Innovation. This publication also makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration.With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2021-001131-S).Peer reviewe

The SIB Swiss Institute of Bioinformatics' resources: focus on curated databases

The SIB Swiss Institute of Bioinformatics (www.isb-sib.ch) provides world-class bioinformatics databases, software tools, services and training to the international life science community in academia and industry. These solutions allow life scientists to turn the exponentially growing amount of data into knowledge. Here, we provide an overview of SIB's resources and competence areas, with a strong focus on curated databases and SIB's most popular and widely used resources. In particular, SIB's Bioinformatics resource portal ExPASy features over 150 resources, including UniProtKB/Swiss-Prot, ENZYME, PROSITE, neXtProt, STRING, UniCarbKB, SugarBindDB, SwissRegulon, EPD, arrayMap, Bgee, SWISS-MODEL Repository, OMA, OrthoDB and other databases, which are briefly described in this article

Can improved canopy light transmission ameliorate loss of photosynthetic efficiency in the shade? An investigation of natural variation in Sorghum bicolor.

Previous studies have found that maximum quantum yield of CO2 assimilation (Φ CO2,max,app) declines in lower canopies of maize and miscanthus, a maladaptive response to self-shading. These observations were limited to single genotypes, leaving it unclear whether the maladaptive shade response is a general property of this C4 grass tribe, the Andropogoneae. We explored the generality of this maladaptation by testing the hypothesis that erect leaf forms (erectophiles), which allow more light into the lower canopy, suffer less of a decline in photosynthetic efficiency than drooping leaf (planophile) forms. On average, Φ CO2,max,app declined 27% in lower canopy leaves across 35 accessions, but the decline was over twice as great in planophiles than in erectophiles. The loss of photosynthetic efficiency involved a decoupling between electron transport and assimilation. This was not associated with increased bundle sheath leakage, based on 13C measurements. In both planophiles and erectophiles, shaded leaves had greater leaf absorptivity and lower activities of key C4 enzymes than sun leaves. The erectophile form is considered more productive because it allows a more effective distribution of light through the canopy to support photosynthesis. We show that in sorghum, it provides a second benefit, maintenance of higher Φ CO2,max,app to support efficient use of that light resource