The analysis and combination of data from different gamma-ray instruments involves the use of collaboration proprietary software and case-by-case methods. The effort of defining a common data format ...for high-level data, namely event lists and instrument response functions (IRFs), has recently started for very-high-energy gamma-ray instruments, driven by the upcoming Cherenkov Telescope Array (CTA). In this work we implemented this prototypical data format for a small set of MAGIC, VERITAS, FACT, and H.E.S.S. Crab nebula observations, and we analyzed them with the open-source gammapy software package. By combining data from Fermi-LAT, and from four of the currently operating imaging atmospheric Cherenkov telescopes, we produced a joint maximum likelihood fit of the Crab nebula spectrum. Aspects of the statistical errors and the evaluation of systematic uncertainty are also commented upon, along with the release format of spectral measurements. The results presented in this work are obtained using open-access on-line assets that allow for a long-term reproducibility of the results.
Porous graphitic carbons were obtained from wood precursors using Ni as a graphitization catalyst during pyrolysis. The structure of the resulting material retains that of the original wood ...precursors with highly aligned, hierarchical porosity. Thermal characterization was performed by means of thermogravimetry and differential scanning calorimetry, and the onset temperature for graphitization was determined to be ~900 °C. Structural and microstructural characterization was performed by means of electron microscopy, electron and x-ray diffraction, and Raman spectroscopy. The effect of maximum pyrolysis temperature on the degree of graphitization was assessed. No significant temperature effect was detected by means of Raman scattering in the range of 1000–1400 °C, but at temperatures over the melting point of the catalyst, the formation of graphite grains with long-range order was detected.
This paper presents a practical approach to obtain reduced-order models for electric networks expressed in the dynamic harmonic domain (DHD). The proposed method reduces the DHD system of ordinary ...differential equations first in the harmonic sense via a voltage-based frequency-scan procedure and subsequently in the state sense via truncated balanced realizations. The harmonic-selection and truncation stage substantially reduces the original full-size system. The state-reduction process is applied to the already harmonic-reduced system, achieving further reduction. Two networks are used as case studies to demonstrate the reduction properties of the proposed model-order reduction methodology.
•Instantaneous rolling invariant between axodes.•Instantaneous sliding invariant between axodes.•Induced curvature.•Osculating and spooning hyperboloids.•Generalized curvature theory for axodes and ...striction curves.
It is well established that generalized spatial motion of a rigid body can be defined in terms of two axodes; a fixed axode and a moving axode. These axodes are ruled surfaces that uniquely roll and slide upon one another. Presented are two instantaneous invariants that define relative motion between two axodes. These invariants are based on the instantaneous screw axis (ISA) or line-tangency shared by two axodes in mesh. One invariant is the relative angular displacement (rolling) about the ISA and the other invariant is the relative axial displacement (sliding) along the ISA. Both invariants are ratios expressed in terms of the normal curvature and geodesic torsion for any point on the ISA. An induced curvature is introduced to quantify the combined rolling and sliding displacement. Two osculating hyperboloids are established in terms of induced curvature, which when combined, create a skew axis gear pair with uniform motion that matches the instantaneous invariants of the axodes. A skew axis gear set with elliptical motion is presented to demonstrate generalized axodes, instantaneous invariants, induced curvature, and osculating hyperboloids.
Optimal and Robust Control in DC Microgrids Ornelas-Tellez, Fernando; Rico-Melgoza, J. Jesus; Espinosa-Juarez, Elisa ...
IEEE transactions on smart grid,
11/2018, Letnik:
9, Številka:
6
Journal Article
Recenzirano
This paper presents an optimal and robust nonlinear control scheme to achieve trajectory tracking for disturbed nonlinear systems, which is applied for the control of power converters in dc ...microgrids. The state-feedback optimal controller synthesis is based on the solution of the Hamilton-Jacobi-Bellman equation, which considers the minimization of a cost functional (performance index), resulting in an efficient control strategy. The proposed methodology is used to efficiently regulate the power flow from renewable resources into the utility grid, to supply energy to loads, and to storage energy. Simulation results are presented to assess the performance of the proposed controller for a case study dc microgrid, where its adequate operation depends on the dc bus voltage regulation; hence, for guaranteeing such voltage regulation through the converter (inverter) connected to the utility grid, the optimal control scheme is in addition combined with a super-twisting controller (a robust sliding mode-based control technique) to enhance the inverter control strategy robustness.
High-Throughput Venomics Slagboom, Julien; Derks, Rico J. E.; Sadighi, Raya ...
Journal of proteome research,
06/2023, Letnik:
22, Številka:
6
Journal Article
Recenzirano
Odprti dostop
In this study, we present high-throughput (HT) venomics, a novel analytical strategy capable of performing a full proteomic analysis of a snake venom within 3 days. This methodology comprises a ...combination of RP-HPLC-nanofractionation analytics, mass spectrometry analysis, automated in-solution tryptic digestion, and high-throughput proteomics. In-house written scripts were developed to process all the obtained proteomics data by first compiling all Mascot search results for a single venom into a single Excel sheet. Then, a second script plots each of the identified toxins in so-called Protein Score Chromatograms (PSCs). For this, for each toxin, identified protein scores are plotted on the y-axis versus retention times of adjacent series of wells in which a toxin was fractionated on the x-axis. These PSCs allow correlation with parallel acquired intact toxin MS data. This same script integrates the PSC peaks from these chromatograms for semiquantitation purposes. This new HT venomics strategy was performed on venoms from diverse medically important biting species; Calloselasma rhodostoma, Echis ocellatus, Naja pallida, Bothrops asper, Bungarus multicinctus, Crotalus atrox, Daboia russelii, Naja naja, Naja nigricollis, Naja mossambica, and Ophiophagus hannah. Our data suggest that high-throughput venomics represents a valuable new analytical tool for increasing the throughput by which we can define venom variation and should greatly aid in the future development of new snakebite treatments by defining toxin composition.
Imbalances in the amounts of amyloid-β peptides (Aβ) generated by the membrane proteases β- and γ-secretase are considered as a trigger of Alzheimer's disease (AD). Cell-free studies of γ-secretase ...have shown that increasing membrane thickness modulates Aβ generation but it has remained unclear if these effects are translatable to cells. Here we show that the very long-chain fatty acid erucic acid (EA) triggers acyl chain remodeling in AD cell models, resulting in substantial lipidome alterations which included increased esterification of EA in membrane lipids. Membrane remodeling enhanced γ-secretase processivity, resulting in the increased production of the potentially beneficial Aβ37 and/or Aβ38 species in multiple cell lines. Unexpectedly, we found that the membrane remodeling stimulated total Aβ secretion by cells expressing WT γ-secretase but lowered it for cells expressing an aggressive familial AD mutant γ-secretase. We conclude that EA-mediated modulation of membrane composition is accompanied by complex lipid homeostatic changes that can impact amyloidogenic processing in different ways and elicit distinct γ-secretase responses, providing critical implications for lipid-based AD treatment strategies.
Drug repositioning explores the reuse of non-cancer drugs to treat tumors. In this work, we evaluated the effect of the combination of chloroquine and propranolol on colorectal and triple-negative ...breast cancers. Using as in vitro models the colorectal cancer cell lines HCT116, HT29, and CT26, and as triple-negative breast cancer models the 4T1, M-406, and MDA-MB-231 cell lines, we evaluated the effect of the drugs combination on the viability, apoptosis, clonogenicity, and cellular migratory capacity. To explore the in vivo effects of the combination on tumor growth and metastasis development we employed graft models in BALB/c, nude, and CBi mice. In vitro studies showed that combined treatment decreased cell viability in a dose-dependent manner and increased apoptosis. Also, we demonstrated that these drugs act synergically and that it affects clonogenicity and migration. In vivo studies indicated that this drug combination was effective on colorectal models but only partially on breast cancer. These results contributed to the search for new and safe treatments for colorectal and triple-negative carcinomas.
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