Extraction and Visualization of Swirl and Tumble Motion from Engine Simulation Data

Figure 1: Unsteady visualization of vortices from in-cylinder tumble motion in a gas engine and its relationship to the boundary. During the valve cycle (left to right), the piston head that shapes the bottom of the geometry moves down (not shown). The volume rendering shows vortices using a two-dimensional transfer function of λ2 and normalized helicity (legend). The main tumble vortex is extracted and visible as off-center and with an undesired diagonal orientation. The flow structure on the boundary is visualized using boundary topology. A direct correspondence between the volume and boundary visualizations can be observed. In the third image, the intersection of the main vortex with the boundary results in critical points on the front and back walls. Optimizing the combustion process within an engine block is central to the performance of many motorized vehicles. Associated with this process are two important patterns of flow: swirl and tumble motion, which optimize the mixing of fluid within each of an engine’s cylinders. Good visualizations are necessary to analyze the simulation data of these in-cylinder flows. We present a range of methods including integral, feature-based, and imagebased schemes with the goal of extracting and visualizing these tw

3D Arbitrary Channel Fabrication for Lab on a Chip Applications using Chemical Decomposition

This article demonstrate a simple method to use of three-dimensionally (3D) printed molds that are chemically decomposable for rapid fabrication of complex and arbitrary microchannel geometries. These complex microchannel are unachievable through existing soft lithography techniques. The molds are printed directly from hand held 3D printing pen that can print in midair, making rapid prototyping of microfluidic devices possible in hours. PLA based copper filament is used to print the arbitrary channels. The printed channels are then placed inside PDMS and PDMS is cured. The cured sample is then immersed in chemical solution (Acetic Acid + Sodium Chloride+ Hydrogen peroxide), which decomposes the PLA based copper channel thus leaving an empty channel inside the PDMS block. This method enable precise control of various device geometries, such as the profile of the channel cross-section and variable channel diameters in a single device

Deep learning predicts total knee replacement from magnetic resonance images

Knee Osteoarthritis (OA) is a common musculoskeletal disorder in the United States. When diagnosed at early stages, lifestyle interventions such as exercise and weight loss can slow OA progression, but at later stages, only an invasive option is available: total knee replacement (TKR). Though a generally successful procedure, only 2/3 of patients who undergo the procedure report their knees feeling ''normal'' post-operation, and complications can arise that require revision. This necessitates a model to identify a population at higher risk of TKR, particularly at less advanced stages of OA, such that appropriate treatments can be implemented that slow OA progression and delay TKR. Here, we present a deep learning pipeline that leverages MRI images and clinical and demographic information to predict TKR with AUC $0.834 \pm 0.036$ (p < 0.05). Most notably, the pipeline predicts TKR with AUC $0.943 \pm 0.057$ (p < 0.05) for patients without OA. Furthermore, we develop occlusion maps for case-control pairs in test data and compare regions used by the model in both, thereby identifying TKR imaging biomarkers. As such, this work takes strides towards a pipeline with clinical utility, and the biomarkers identified further our understanding of OA progression and eventual TKR onset.Comment: 18 pages, 5 figures (4 in main article, 1 supplemental), 8 tables (5 in main article, 3 supplemental). Submitted to Scientific Reports and currently in revisio

L1448-MM Observations by the Herschel Key Program, "Dust, Ice, and Gas in Time" (DIGIT)

We present Herschel/Photodetector Array Camera and Spectrometer (PACS) observations of L1448-MM, a Class 0 protostar with a prominent outflow. Numerous emission lines are detected at 55 1000 K) environment, indicative of a shock origin. For OH, IR-pumping processes play an important role in the level population. The molecular emission in L1448-MM is better explained with a C-shock model, but the atomic emission of PACS [O I] and Spitzer/Infrared Spectrograph [Si II] emission is not consistent with C-shocks, suggesting multiple shocks in this region. Water is the major line coolant of L1448-MM in the PACS wavelength range, and the best-fit LVG models predict that H2O and CO emit (50%-80%) of their line luminosity in the PACS wavelength range.Herschel Open Time Key Project ProgramNASAJet Propulsion Laboratory, California Institute of TechnologyBasic Science Research Program through the National Research Foundation of Korea (NRF)Ministry of Education of the Korean government NRF-2010-0008704, NRF-2012R1A1A2044689Core Research Program of NRFMinistry of Science, ICTFuture Planning of the Korean government NRF-2011-0015816Korea Astronomy and Space Science InstituteKorean government (MEST)Astronom

FTIR Study of Copper Agglomeration during Atomic Layer Deposition of Copper

The growth of of metallic copper by atomic layer deposition (ALD) using copper(I) di-sec-butylacetamidinate $([Cu(^sBu-amd)]_2)$ and molecular hydrogen $(H_2)$ on $SiO_2/Si$ surfaces has been studied. The mechanisms for the initial surface reaction and chemical bonding evolutions with each ALD cycle are inferred from in situ Fourier transform infrared spectroscopy (FTIR) data. Spectroscopic evidence for Cu agglomeration on $SiO_2$ is presented involving the intensity variations of the $SiO_2$ LO/TO phonon modes after chemical reaction with the Cu precursor and after the $H_2$ precursor cycle. These intensity variations are observed over the first 20 ALD cycles at 185°C.Chemistry and Chemical Biolog

In-situ Infrared Characterization During Atomic Layer Deposition of Lanthanum Oxide

Mechanisms of atomic layer deposition (ALD) growth of lanthanum oxide on H-terminated Si(111) using lanthanum tris(N,N′-diisopropylacetamidinate) (La(iPr-MeAMD)3) are investigated using infrared (IR) absorption spectroscopy. The reactivity of this amidinate precursor is high, with almost all surface Si−H bonds consumed after 5 ALD cycles at 300 °C. Gas phase IR spectra show that, although most of the precursor (La(iPr-MeAMD)3) remains intact, a strong feature at 1665 cm−1, characteristic of a hydrogenated and dissociated free ligand with localized electrons in the N−CN bonds, is present. Such partial precursor dissociation in the gas phase is due to hydrolysis by traces of water vapor remaining in the reactor, even after purging. As a result, some Si−O−La bonds are formed upon reaction with the surface during the first La(iPr-MeAMD)3 pulse, prior to any water pulse. During film growth, acetate/carbonate and hydroxyl impurities are incorporated into the film. Annealing to 500 °C in dry N2 removes these impurities but fosters the growth of interfacial SiO2. Deposition at 300 °C leads to decomposition of adsorbed ligands, as evidenced by the formation of cyanamide or carbodiimide vibrational bands (or both) at 1990 and 2110 cm−1, respectively. Despite this decomposition, ideal self-limited ALD growth is maintained because the decomposed ligands are removed by the subsequent water pulse. Growth of pure lanthanum oxide films is often characterized by nonuniform film thickness if purging is not complete because of reversible absorption of water by the La2O3 film. Uniform ALD growth can be maintained without a rigorous dry purge by introducing alternating trimethylaluminum (TMA)/D2O ALD cycles between La/D2O cycles.Chemistry and Chemical Biolog

Mothersʼ Psychological Distress and Feeding of Their Preterm Infants

To examine the change in psychological distress of mothers of preterm infants and its association with maternal feeding behaviors as the infant transitions to full oral feeding

Role of activating transcription factor 4 in the hepatic response to amino acid depletion by asparaginase

The anti-leukemic agent asparaginase activates the integrated stress response (ISR) kinase GCN2 and inhibits signaling via mechanistic target of rapamycin complex 1 (mTORC1). The study objective was to investigate the protective role of activating transcription factor 4 (ATF4) in controlling the hepatic transcriptome and mediating GCN2-mTORC1 signaling during asparaginase. We compared global gene expression patterns in livers from wildtype, Gcn2 -/-, and Atf4 -/- mice treated with asparaginase or excipient and further explored selected responses in livers from Atf4 +/- mice. Here, we show that ATF4 controls a hepatic gene expression profile that overlaps with GCN2 but is not required for downregulation of mTORC1 during asparaginase. Ingenuity pathway analysis indicates GCN2 independently influences inflammation-mediated hepatic processes whereas ATF4 uniquely associates with cholesterol metabolism and endoplasmic reticulum (ER) stress. Livers from Atf4 -/- or Atf4 +/- mice displayed an amplification of the amino acid response and ER stress response transcriptional signatures. In contrast, reduction in hepatic mTORC1 signaling was retained in Atf4 -/- mice treated with asparaginase