A
bstract
We discuss the theoretical bases that underpin the automation of the computations of tree-level and next-to-leading order cross sections, of their matching to parton shower simulations, and ...of the merging of matched samples that differ by light-parton multiplicities. We present a computer program, MadGraph5 aMC@NLO, capable of handling all these computations — parton-level fixed order, shower-matched, merged — in a unified framework whose defining features are flexibility, high level of parallelisation, and human intervention limited to input physics quantities. We demonstrate the potential of the program by presenting selected phenomenological applications relevant to the LHC and to a 1-TeV
e
+
e
−
collider. While next-to-leading order results are restricted to QCD corrections to SM processes in the first public version, we show that from the user viewpoint no changes have to be expected in the case of corrections due to any given renormalisable Lagrangian, and that the implementation of these are well under way.
The present work addresses the detailed structural elucidation by high resolution techniques of both liquid pyrolysis products from slow pyrolysis of crambe seeds. Bio-oil and aqueous phase were ...obtained at 400 °C with 32% and 15.8% (w/w) yield and were separated by density difference. Lyophilization was applied to concentrate the organic compounds present in aqueous phase (OCAP). Bio-oil and the OCAP were analyzed by comprehensive bidimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS) and positive and negative-ion electrospray (ESI) high resolution Orbitrap mass spectrometry (HRMS). For the bio-oil, 1,400 analytes were identified by GC×GC-TOFMS and the most abundant classes were hydrocarbons (448.6 mg g−1) and N-containing compounds (172.2 mg g−1). In the bio-oil ESI-(+) Orbitrap HRMS data, the N2 class was the most abundant (79.9%). In the negative mode, ca. 87.6% of assigned peaks corresponded to O2 class for bio-oil. The major compounds identified by GC×GC-TOFMS in the OCAP were oxygenated (49.8%) and NO containing compounds (45.9%). ESI (−) Orbitrap HRMS analysis for OCAP presented high percentage of O2 (57.2%) and NO (28.3%) classes, while ESI (+) Orbitrap MS of N2 (51.8%) and NO (28.8%) classes. The aqueous fraction composition profile indicates a potential biological activity due to the presence of N-heterocyclic compounds and the bio-oil (38.9 MJ kg−1; 5.4% H2O) has the potential to be used as a second generation (ASTM D7544) or hydrotreated to improve fuel quality.
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•Crambe is an interesting non-food biomass with a low production cost.•The liquid products of slow pyrolysis from crambe seeds were analyzed.•The bio-oil consists mainly of compounds with apolar characteristics.•The organic compounds present in the aqueous phase (OCAP) have a more polar profile.•Bio-oil is rich in hydrocarbons while OCAP is rich in N- and O-containing compounds.
The mean crystal size, the suspension density and the liquid concentration are the three most important process parameters to quantify the progress of industrial crystallization processes. It will be ...shown that these parameters can be in-line monitored simultaneously by means of an ultrasonic crystallization monitoring technique (UCM), which will be introduced here in a proof of concept. This process analytical technology (PAT) differs from the known ultrasonic attenuation spectroscopy (UAS). For the UCM the ultrasonic velocity and attenuation were correlated and related to characteristic events during a crystallization process measured at only one frequency (no spectra of frequencies as it is used for UAS). The results shown in this study prepare the ground to establish the UCM as a simple, less complex, robust, universal applicable, inexpensive and, therefore, a winning alternative PAT to monitor and control in-line the solid as well as the liquid phase in the industrial crystallization by means of only one measuring device with two sensors.
► An ultrasonic crystallization monitoring technique (UCM) is introduced. ► The mean crystal size can be measured by UCM. ► The suspension density can be measured by UCM. ► The liquid concentration can be measured by UCM. ► Only one device and two sensors are required for the measurements.
The chemical composition of ambient organic aerosols was analyzed using complementary mass spectrometric techniques during a field study in central Europe in July 2014 (Fichtelgebirge – Biogenic ...Emission and Aerosol Chemistry, F-BEACh 2014). Among several common biogenic secondary organic aerosol (BSOA) marker compounds, 93 acidic oxygenated hydrocarbons were detected with elevated abundances and were thus attributed to be characteristic for the organic aerosol mass at the site. Monoterpene measurements exhibited median mixing ratios of 1.6 and 0.8 ppbV for in and above canopy levels respectively. Nonetheless, concentrations for early-generation oxidation products were rather low, e.g., pinic acid (c = 4.7 (±2.5) ng m−3). In contrast, high concentrations were found for later-generation photooxidation products such as 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA, c = 13.8 (±9.0) ng m−3) and 3-carboxyheptanedioic acid (c = 10.2 (±6.6) ng m−3), suggesting that aged aerosol masses were present during the campaign period. In agreement, HYSPLIT trajectory calculations indicate that most of the arriving air masses traveled long distances (> 1500 km) over land with high solar radiation. In addition, around 47 % of the detected compounds from filter sample analysis contained sulfur, confirming a rather high anthropogenic impact on biogenic emissions and their oxidation processes. Among the sulfur-containing compounds, several organosulfates, nitrooxy organosulfates, and highly oxidized organosulfates (HOOS) were tentatively identified by high-resolution mass spectrometry. Correlations among HOOS, sulfate, and highly oxidized multifunctional organic compounds (HOMs) support the hypothesis of previous studies that HOOS are formed by reactions of gas-phase HOMs with particulate sulfate. Moreover, periods with high relative humidity indicate that aqueous-phase chemistry might play a major role in HOOS production. However, for dryer periods, coinciding signals for HOOS and gas-phase peroxyradicals (RO2 ) were observed, suggesting RO2 to be involved in HOOS formation.
Continuing our previous studies on QED and QCD processes, we use the graphics processing unit (GPU) for fast calculations of helicity amplitudes for general Standard Model (SM) processes. Additional ...HEGET codes to handle all SM interactions are introduced, as well as the program MG2CUDA that converts arbitrary MadGraph generated HELAS amplitudes (FORTRAN) into HEGET codes in CUDA. We test all the codes by comparing amplitudes and cross sections for multi-jet processes at the LHC associated with production of single and double weak bosons, a top-quark pair, Higgs boson plus a weak boson or a top-quark pair, and multiple Higgs bosons via weak-boson fusion, where all the heavy particles are allowed to decay into light quarks and leptons with full spin correlations. All the helicity amplitudes computed by HEGET are found to agree with those computed by HELAS within the expected numerical accuracy, and the cross sections obtained by gBASES, a GPU version of the Monte Carlo integration program, agree with those obtained by BASES (FORTRAN), as well as those obtained by MadGraph. The performance of GPU was over a factor of 10 faster than CPU for all processes except those with the highest number of jets.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The coating of pharmaceutical compounds is a field of high interest. As most of the coating materials form an amorphous layer around the material, the studies on crystalline coatings are rare. In ...this work the progress in this domain should be summarized and innovative results concerning crystalline hollow needles as coating material are presented. Since the first reports on needles formed via a solvent-mediated phase transition from solvates to hydrates, the field could be widened to hydrate-to-anhydrate and anhydrate-to-hydrate transformations. Novel investigations on hollow theophylline monohydrate and carbamazepine dihydrate needles are presented. It is shown that the inclusion of substances into the hollow needle crystals is feasible by simple means, which enable an application in industry as coating for sensitive materials.
► Methods for crystalline coatings are discussed. ► New approach featuring hollow crystalline needles is presented. ► Needles can be produced by a solvate-to-nonsolvate or a nonsolvate-to-solvate solvent-mediated phase transfer. ► New examples for nonsolvate-to-solvate transfers are demonstrated. ► Acicular crystals can be filled with various substances and utilized as protective coating of pharmaceutical compounds.
We use the graphics processing unit (GPU) for fast calculations of helicity amplitudes of physics processes. As our first attempt, we compute
(
n
=2 to 8) processes in
pp
collisions at
TeV by ...transferring the MadGraph generated HELAS amplitudes (FORTRAN) into newly developed HEGET (
H
ELAS
E
valuation with
G
PU
E
nhanced
T
echnology) codes written in CUDA, a C-platform developed by NVIDIA for general purpose computing on the GPU. Compared with the usual CPU programs, we obtain a 40–150 times better performance on the GPU.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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