Numerical investigation on the use of Dimethyl Ether (DME) as an alternative fuel for compression-ignition engines

Dimethyl Ether (DME) is an oxygenated fuel that could favour the transition of the heavy-duty transportation sector to carbon neutrality thanks to its similarities in terms of thermophysical properties with diesel fuel, which will facilitate the retrofitting of existing architectures, and the possibility to achieve good trade-offs between NOx emissions, soot formation and overall combustion efficiency. The possibility of producing it from a multitude of carbon-neutral sources and the low hydrogen-to-carbon ratio would allow for an overall lower CO2 output, making an attractive option in limiting the global warming impact of the heavy-duty transportation sector. In the present work, a numerical analysis of the combustion process of DME is carried out. First, the numerical setup is validated against experimental data available for a constant volume vessel with an initial density of 14.8 kg/m3, discussing the capabilities of a chemistry-based combustion model using tabulated kinetics of homogeneous reactors: the Tabulated Well Mixed (TWM) model. Ignition delay times (IDT) are compared for a wide range of temperatures, from 750 K to 1100 K, and oxygen concentrations, from 15% to 21%. The same setup is then applied in the simulation of a heavy-duty internal combustion engine (ICE). A first validation was done to assess the performance of the numerical methodology in a traditional Mixing Controlled Compression Ignition (MCCI) scenario. Then, two other points were simulated: an MCCI condition with 35% of EGR and a Late-Premixed Charge Compression Ignition (L-PCCI) one, with 35% of EGR and an SOIe of 4 CAD aTDC. Local temperature distributions were compared, analyzing the effect of these technologies in NOx emission mitigation and their impact on gross indicated efficiency (& eta;g), showing the advantages that using DME can have on a real-world application

Extrapyramidal signs in normal pressure hydrocephalus: an objective assessment

<p>Abstract</p> <p>Background</p> <p>Beyond the classic Normal Pressure Hydrocephalus (NPH) triad of gait disturbance, incontinence, and dementia are characteristic signs of motor dysfunction in NPH patients. We used highly sensitive and objective methods to characterize upper limb extrapyramidal signs in a series of NPH subjects compared with controls. Concentrated evaluation of these profound, yet underappreciated movement disorders of NPH before and after techniques of therapeutic intervention may lead to improved diagnosis, insight into pathophysiology, and targeted treatment.</p> <p>Methods</p> <p>Twenty-two (22) consecutive NPH patients and 17 controls performed an upper limb motor task battery where highly sensitive and objective measures of akinesia/bradykinesia, tone, and tremor were conducted. NPH subjects performed this test battery before and more than 36 h after continuous CSF drainage via a spinal catheter over 72 h and, in those subjects undergoing permanent ventriculo-peritoneal shunt placement, at least 12 weeks later. Control subjects performed the task battery at the same dates as the NPH subjects. Statistical analyses were applied to group populations of NPH and control subjects and repeated measures for within subject performance.</p> <p>Results</p> <p>Twenty (20) NPH subjects remained in the study following CSF drainage as did 14 controls. NPH subjects demonstrated akinesia/bradykinesia (prolonged reaction and movement times) and increased resting tone compared with controls. Furthermore, the NPH group demonstrated increased difficulty with self-initiated tasks compared with stimulus-initiated tasks. Following CSF drainage, some NPH subjects demonstrated reduced movement times with greater improvement in self- versus stimulus-initiated tasks. Group reaction time was unchanged. Resting tremor present in one NPH subject resolved following shunt placement. Tone measures were consistent for all subjects throughout the study.</p> <p>Conclusion</p> <p>Clinical motor signs of NPH subjects extend beyond gait deficits and include extrapyramidal manifestations of bradykinesia, akinesia, rigidity, and propensity to perform more poorly when external cues to move are absent. Objective improvement of some but not all of these features was seen following temporary or permanent CSF diversion.</p

Machine Learning Techniques for Personalized Detection of Epileptic Events in Clinical Video Recordings

Continuous patient monitoring is essential to achieve an effective and optimal patient treatment in the intensive care unit. In the specific case of epilepsy it is the only way to achieve a correct diagnosis and a subsequent optimal medication plan if possible. In addition to automatic vital sign monitoring, epilepsy patients need manual monitoring by trained personnel, a task that is very difficult to be performed continuously for each patient. Moreover, epileptic manifestations are highly personalized even within the same type of epilepsy. In this work we assess two machine learning methods, dictionary learning and an autoencoder based on long short-term memory (LSTM) cells, on the task of personalized epileptic event detection in videos, with a set of features that were specifically developed with an emphasis on high motion sensitivity. According to the strengths of each method we have selected different types of epilepsy, one with convulsive behaviour and one with very subtle motion. The results on five clinical patients show a highly promising ability of both methods to detect the epileptic events as anomalies deviating from the stable/normal patient status

Decadal changes in summertime reactive oxidized nitrogen and surface ozone over the Southeast United States

Widespread efforts to abate ozone (O3) smog have significantly reduced emissions of nitrogen oxides (NOx) over the past 2 decades in the Southeast US, a place heavily influenced by both anthropogenic and biogenic emissions. How reactive nitrogen speciation responds to the reduction in NOx emissions in this region remains to be elucidated. Here we exploit aircraft measurements from ICARTT (July–August 2004), SENEX (June–July 2013), and SEAC4RS (August–September 2013) and long-term ground measurement networks alongside a global chemistry–climate model to examine decadal changes in summertime reactive oxidized nitrogen (RON) and ozone over the Southeast US. We show that our model can reproduce the mean vertical profiles of major RON species and the total (NOy) in both 2004 and 2013. Among the major RON species, nitric acid (HNO3) is dominant (∼ 42–45%), followed by NOx (31%), total peroxy nitrates (ΣPNs; 14%), and total alkyl nitrates (ΣANs; 9–12%) on a regional scale. We find that most RON species, including NOx, ΣPNs, and HNO3, decline proportionally with decreasing NOx emissions in this region, leading to a similar decline in NOy. This linear response might be in part due to the nearly constant summertime supply of biogenic VOC emissions in this region. Our model captures the observed relative change in RON and surface ozone from 2004 to 2013. Model sensitivity tests indicate that further reductions of NOxemissions will lead to a continued decline in surface ozone and less frequent high-ozone events

SAMPLE ANALYSIS METHODOLOGY UTILIZNGELECTROMAGNETIC RADATION

Simultaneous use of wavelengths in at least two ranges Selected from RADIO, MICRO. FIR, IR, NIR-VIS-NUV. UV, DUV, VUV EUV, XRAY in a regression procedure to evaluate parameters in mathematical dispersion structures to model dielectric functions

Bi(OTf)(3)-, TfOH-, and TMSOTf-Mediated, One-Pot Epoxide Rearrangement, Addition, and Intramolecular Silyl-Modified Sakurai (ISMS) Cascade toward Dihydropyrans: Comparison of Catalysts and Role of Bi(OTf)(3)

Catalytic quantities of bismuth(III) triflate efficiently initiate the rearrangement of epoxides to aldehydes, which subsequently react with (Z)-delta-hydroxyalkenylsilanes to afford 2,6-disubstituted 3,6-dihydro-2H-pyrans. Isolated yields of desired products using Bi(OTf)(3) were compared with yields obtained when the reactions were run with TfOH and TMSOTf in the presence and absence of several additives. These studies, as well as NMR spectroscopic analyses, indicate an initial Lewis acid/base interaction between Bi(OTf)(3) and substrates providing TfOH in situ

Metabolic changes in hypertrophic cardiomyopathies : Scientific update from the Working Group of Myocardial Function of the European Society of Cardiology

JV is supported by the Netherlands Cardiovascular Research Initiative, an initiative with support of the Dutch Heart Foundation, CVON2014-40 DOSIS. SH has received funding from the European Union Commission’s Seventh Framework programme under grant agreement N° 305507 (HOMAGE), N° 602904 (FIBROTARGETS) and FP7-Health-2013- Innovations-1 N° 602156 (HECATOS). . We acknowledge the support from the Netherlands Cardiovascular Research Initiative, an initiative with support of the Dutch Heart Foundation, CVON2011-ARENA, CVON2016-Early HFPEF, and ShePREDICTS. This research is cofinanced as a PPP-allowance Research and Innovation by the Ministry of Economic Affairs within Top Sector Life sciences & Health. This research was co-funded by the C3 project “Vision Core Leuven” of the Leuven UniversityPeer reviewedPublisher PD

Risk for life-threatening arrhythmia in newly diagnosed peripartum cardiomyopathy with low ejection fraction: a German multi-centre analysis

Introduction Peripartum cardiomyopathy (PPCM) is a rare cardiomyopathy characterized by an acute reduction in left ventricular ejection fraction (LVEF). Sudden deaths during the course of PPCM are reported to be elevated, the underlying mechanisms remains unknown. The aim of the present multi-centre study was to evaluate the arrhythmia burden in a multi-centre approach in patients with PPCM using a wearable cardioverter/defibrillator (WCD). Methods and results Forty-nine patients from 16 German centres with newly diagnosed PPCM and LVEF <= 35% receiving a WCD were included in this retrospective analysis. Mean follow-up was 15 +/- 10 months. At diagnosis, mean age was 33 +/- 5 years, parity was 2.1 +/- 1.6, LVEF was 21 +/- 7%, NYHA functional class was 3.4 +/- 0.7. Mean wear time was 120 +/- 106 days, mean wear time per day was 21.4 +/- 3.3 h. Six (12%) patients presented eight ventricular tachyarrhythmias during WCD period: five episodes of VF, two sustained ventricular tachycardia (VT) and one non-sustained VT occurred. Conclusion This multicentre study underpins the elevated risk for ventricular tachyarrhythmias in patients with newly diagnosed PPCM and reduced LVEF. A WCD should be considered for 3-6 months in these patients to prevent sudden cardiac death from ventricular tachyarrhythmias

Ozone production chemistry in the presence of urban plumes

Ozone pollution affects human health, especially in urban areas on hot sunny days. Its basic photochemistry has been known for decades and yet it is still not possible to correctly predict the high ozone levels that are the greatest threat. The CalNex_SJV study in Bakersfield CA in May/June 2010 provided an opportunity to examine ozone photochemistry in an urban area surrounded by agriculture. The measurement suite included hydroxyl (OH), hydroperoxyl (HO_2), and OH reactivity, which are compared with the output of a photochemical box model. While the agreement is generally within combined uncertainties, measured HO2 far exceeds modeled HO_2 in NO_x-rich plumes. OH production and loss do not balance as they should in the morning, and the ozone production calculated with measured HO_2 is a decade greater than that calculated with modeled HO_2 when NO levels are high. Calculated ozone production using measured HO2 is twice that using modeled HO_2, but this difference in calculated ozone production has minimal impact on the assessment of NOx-sensitivity or VOC-sensitivity for midday ozone production. Evidence from this study indicates that this important discrepancy is not due to the HO_2 measurement or to the sampling of transported plumes but instead to either emissions of unknown organic species that accompany the NO emissions or unknown photochemistry involving nitrogen oxides and hydrogen oxides, possibly the hypothesized reaction OH + NO + O_2 → HO_2 + NO_2

In peripartum cardiomyopathy plasminogen activator inhibitor-1 is a potential new biomarker with controversial roles

Aims Peripartum cardiomyopathy (PPCM) is a life-threatening heart disease occurring in previously heart-healthy women. A common pathomechanism in PPCM involves the angiostatic 16 kDa-prolactin (16 kDa-PRL) fragment, which via NF-kappa B-mediated up-regulation of microRNA-(miR)-146a induces vascular damage and heart failure. We analyse whether the plasminogen activator inhibitor-1 (PAI-1) is involved in the pathophysiology of PPCM. Methods and results In healthy age-matched postpartum women (PP-Ctrl, n = 53, left ventricular ejection fraction, LVEF > 55%), PAI-1 plasma levels were within the normal range (21 +/- 10 ng/mL), but significantly elevated (64 +/- 38 ng/mL, P <0.01) in postpartum PPCM patients at baseline (BL, n = 64, mean LVEF: 23 +/- 8%). At 6-month follow-up (n = 23), PAI-1 levels decreased (36 +/- 14 ng/mL, P <0.01 vs. BL) and LVEF (49 +/- 11%) improved. Increased N-terminal pro-brain natriuretic peptide and Troponin T did not correlate with PAI-1. C-reactive protein, interleukin (IL)-6 and IL-1 beta did not differ between PPCM patients and PP-Ctrl. MiR-146a was 3.6-fold (P <0.001) higher in BL-PPCM plasma compared with PP-Ctrl and correlated positively with PAI-1. In BL-PPCM serum, 16 kDa-PRL coprecipitated with PAI-1, which was associated with higher (P <0.05) uPAR-mediated NF-kappa B activation in endothelial cells compared with PP-Ctrl serum. Cardiac biopsies and dermal fibroblasts from PPCM patients displayed higher PAI-1 mRNA levels (P <0.05) than healthy controls. In PPCM mice (due to a cardiomyocyte-specific-knockout for STAT3, CKO), cardiac PAI-1 expression was higher than in postpartum wild-type controls, whereas a systemic PAI-1-knockout in CKO mice accelerated peripartum cardiac fibrosis, inflammation, heart failure, and mortality. Conclusion In PPCM patients, circulating and cardiac PAI-1 expression are up-regulated. While circulating PAI-1 may add 16 kDa-PRL to induce vascular impairment via the uPAR/NF-kappa B/miR-146a pathway, experimental data suggest that cardiac PAI-1 expression seems to protect the PPCM heart from fibrosis. Thus, measuring circulating PAI-1 and miR-146a, together with an uPAR/NF-kappa B-activity assay could be developed into a specific diagnostic marker assay for PPCM, but unrestricted reduction of PAI-1 for therapy may not be advised