The version 3.0 of the Delphes fast-simulation is presented. The goal of Delphes is to allow the simulation of a multipurpose detector for phenomenological studies. The simulation includes a track ...propagation system embedded in a magnetic field, electromagnetic and hadron calorimeters, and a muon identification system. Physics objects that can be used for data analysis are then reconstructed from the simulated detector response. These include tracks and calorimeter deposits and high level objects such as isolated electrons, jets, taus, and missing energy. The new modular approach allows for greater flexibility in the design of the simulation and reconstruction sequence. New features such as the particle-flow reconstruction approach, crucial in the first years of the LHC, and pile-up simulation and mitigation, which is needed for the simulation of the LHC detectors in the near future, have also been implemented. The Delphes framework is not meant to be used for advanced detector studies, for which more accurate tools are needed. Although some aspects of Delphes are hadron collider specific, it is flexible enough to be adapted to the needs of electron-positron collider experiments.
While it is generally accepted that the rupture of SLM AlSi10Mg tensile specimens occurs at the melt pool boundary, the exact zone and microstructural features responsible for the rupture have not ...been clearly identified. In this study, the microstructures and local mechanical properties at the melt pool boundary are thus analyzed in details. The Si phase fraction and the Si precipitate spacing are measured by image analysis and SEM-EDS analysis. Hardness tests are performed by nanoindentation. Fracture features are observed on broken samples. It is found that the Heat Affected Zone (HAZ) exhibits low hardness due to coarse non-coherent Si precipitates. Void nucleation occurs at the interface between the coarse Si precipitates and the Al matrix by dislocations piling up. For that reason, the HAZ is found to be the preferential region where fracture is likely to occur. This analysis is confirmed by the matching of Si precipitate spacing within the HAZ with dimple spacing observed in fracture surfaces. Moreover, a simple analytical approach of the thermal history during manufacturing, using Rosenthal's equation, allows elucidating the mechanisms by which the processing conditions affect the fracture behavior.
Display omitted
Isoprene carries approximately half of the flux of non-methane volatile organic carbon emitted to the atmosphere by the biosphere. Accurate representation of its oxidation rate and products is ...essential for quantifying its influence on the abundance of the hydroxyl radical (OH), nitrogen oxide free radicals (NO x ), ozone (O3), and, via the formation of highly oxygenated compounds, aerosol. We present a review of recent laboratory and theoretical studies of the oxidation pathways of isoprene initiated by addition of OH, O3, the nitrate radical (NO3), and the chlorine atom. From this review, a recommendation for a nearly complete gas-phase oxidation mechanism of isoprene and its major products is developed. The mechanism is compiled with the aims of providing an accurate representation of the flow of carbon while allowing quantification of the impact of isoprene emissions on HO x and NO x free radical concentrations and of the yields of products known to be involved in condensed-phase processes. Finally, a simplified (reduced) mechanism is developed for use in chemical transport models that retains the essential chemistry required to accurately simulate isoprene oxidation under conditions where it occurs in the atmosphereabove forested regions remote from large NO x emissions.
Laser cladding is a metal deposition technique used to fabricate or repair components made from high value metallic alloys. In the present work Ti–6Al–4V deposits with variable thickness are made to ...assess the use of laser cladding as a repair technology. Both the effect of the building strategy (BS) and the incident energy (IE) on the metallurgical characteristics of the deposits in relation to their complex thermal history have been studying. It is shown that for the configuration consisting in a decreasing track length (DTL) under high IE, a gradient of cooling rate exists that leads to the presence of different phases within the microstructure. Conversely homogeneous microstructures are present either for the configuration with a constant track length (CTL) under high IE, and for the strategy obtained from a DTL under low IE. Depending on the possible heat accumulation the nature of the phases are determined together with hardness maps within the deposits. Some qualification criteria are set prior to tensile tests to selected adequate candidate-deposit that does not weaken the cladded material when it is stressed. A thermo-metallurgical scheme is proposed that helps in understanding the effect of both the BS and the IE on the microstructure.
Display omitted
•Ti–6Al–4V deposits made by laser cladding to simulate repair are investigated.•Effects of the building strategy and the incident energy on deposits were examined.•Both the deposit and its HAZ do not mechanically weaken the repaired part.•A simplified thermo-metallurgical scheme is proposed based on the results.
In this study, we test an intervention in which convicted offenders interacted with an age-progressed avatar representing their future selves in virtual reality. During the interaction, they ...reflected on their current lifestyle, alternating between the perspective of their present self and that of their future self. We hypothesized that this embodied experience would increase their ability to imagine themselves in the future and reduce their engagement in self-defeating behavior, as measured with a self-report survey. In line with expectations, results indicated that the interaction increased vividness of the future self compared to baseline and reduced self-defeating behavior, including alcohol use and overspending, one week later. In addition, increases in vividness were associated with a reduction in self-defeating behavior over and above other concepts relating to the future self, including connectedness, similarity, and valence. The results are based on a small sample and should therefore be considered as indicative of the possibilities of our virtual reality paradigm as an intervention tool to reduce self-defeating behavior.
PurposeThis research work aims to determine the maximum load a thermoplastic gear can withstand without the occurrence of extended contact. The extended contact of polymer gears is usually overlooked ...in basic design calculations, although it considerably affects the gear's load-carrying ability. Although various researchers highlighted the phenomenon, an extensive investigation of the extended contact behaviour is limited. Hence the work aims to investigate the premature and extended contact behaviour of thermoplastic gears and its effect in the gear kinematics, bending stiffness, stresses induced and the roll angle subtended by the gear pair.Design/methodology/approachThe work uses finite element method to perform quasi-static two-dimensional analysis of the meshing gear teeth. The FE model was developed in AutoCAD and analysed using ANSYS 19.1 simulation package. A three-dimensional gear model with all the teeth is computationally intensive for solving a static analysis problem. Hence, planar analysis with a reduced number of teeth is considered to reduce the computational time and difficulty.FindingsThe roll angle subtended at the centre by the path of approach is higher than the path of recess because of the increased load sharing. The contact stress profile followed a unique R-F-R-F pattern in the premature and extended contact regions due to the driven tip-driver flank surface contact. A non-dimensional parameter was formulated correlating the young's modulus, the load applied and deflection induced that can be utilised to predict the occurrence of premature and extended contact in thermoplastic gears.Originality/valueThe gear rating standards for polymer gears are formulated from the conventional metal gears which does not include the effect of gear tooth deflection. The work attempts to explain the gear tooth deflection for various standard thermoplastics and its effect in kinematics. Likewise, a new dimensionless number was introduced to predict the extended contact that will help in appropriate selection of load reducing the possibility of wear.
Lattice structures are meant for light weight structure with a high strength to weight ratio used to carry high loads and high energy absorption capabilities. In the lattice structures, the ...non-stochastic arrangement of members has the ability to control and customize their mechanical properties. The recent developments in additive manufacturing provides freedom in design and gives flexibility to manufacture tailored complex novel lattice structures. In the present investigation, the traditional 2.5D honeycomb and the tessellated open lattice structures with basic crystalline arrangements of the members are considered to study the load carrying capacity, stiffness and energy absorption capabilities by keeping constant volume for each lattice. The results through the experiments and finite element analysis are compared with a novel open lattices structure to show significant improvement in stiffness and high energy absorption with the volume of the material. However, the novel open lattice structure has displayed prominent post yield plateau stresses and energy absorption with sacrificing stiffness and strength significantly.
Display omitted
Plant cell walls to ethanol Jordan, Douglas B; Bowman, Michael J; Braker, Jay D ...
Biochemical journal,
03/2012, Letnik:
442, Številka:
2
Journal Article
Recenzirano
Conversion of plant cell walls to ethanol constitutes second generation bioethanol production. The process consists of several steps: biomass selection/genetic modification, physiochemical ...pretreatment, enzymatic saccharification, fermentation and separation. Ultimately, it is desirable to combine as many of the biochemical steps as possible in a single organism to achieve CBP (consolidated bioprocessing). A commercially ready CBP organism is currently unreported. Production of second generation bioethanol is hindered by economics, particularly in the cost of pretreatment (including waste management and solvent recovery), the cost of saccharification enzymes (particularly exocellulases and endocellulases displaying kcat ~1 s-1 on crystalline cellulose), and the inefficiency of co-fermentation of 5- and 6-carbon monosaccharides (owing in part to redox cofactor imbalances in Saccharomyces cerevisiae).
The aim of the present study was to examine whether early adolescents’ positive development (i.e., resilience and psychological wellbeing) could be enhanced by stimulating three dimensions of ...self-awareness: emotional self-regulation, self-esteem, and self-reflection. An experimental field study (randomized controlled trial) was conducted. Seventh grade students (
N
= 1299;
M
age
= 12.38; 54% boys) completed multiple assessments at the beginning, during, and immediately after the intervention or at parallel time points for students in the control condition. Changes in the assessed constructs were examined with parallel process latent growth curve models. The results showed that increases in emotional self-regulation and self-esteem were related to concurrent increases in both resilience and psychological wellbeing. Changes in self-reflection were, however, not related to changes in these outcomes. The trajectories of change and parallel processes were similar in the intervention and control condition. These findings suggest that interventions aiming to stimulate positive youth development might be optimized by also focusing on youth’s self-awareness, though more knowledge about how self-awareness can be stimulated best is needed. This trial was registered in the Dutch Trial Register, number NL6371 (old number: NTR6554), on July 3, 2017.
Background
Nutritional supplementation is recommended as a prophylactic strategy for nutritional deficiencies after bariatric surgery. Little is known regarding compliance and patients’ perspectives. ...The purpose of the study was to explore supplement intake, compliance, and patients’ perspectives (including barriers, facilitators, and beliefs) and to examine whether compliance to nutritional supplementation can be predicted after bariatric surgery.
Material and Methods
A questionnaire was developed to explore supplement intake and patients’ perspectives. The Probabilistic Medication Compliance Scale (ProMAS) was included and modified to measure behaviors related to supplementation compliance. Content validity was assessed with an expert and patient panel. Consequently, a cross-sectional survey was conducted among patients that underwent bariatric surgery, who were invited using social media. Descriptive statistics and Spearman correlations were applied. Multiple linear regression analysis was performed to predict compliance.
Results
A 58-item questionnaire was developed and content validated, resulting in a scale-content validity index of 0.93. The questionnaire was completed by 402 subjects. Sixty-nine subjects reported not consuming any nutritional supplement (
n
= 69; 17.2%). For the supplement users (
n
= 333; 82.8%), a median ProMAS sum score of 11.0 (7.0–15.0) was observed. Increasing age and medicine intake were positive predictors of compliance (age:
B
= 0.058,
p
= 0.01; medicine intake:
B
= 0.39,
p
< 0.001), while experiencing barriers was identified as a negative predictor of compliance (
B
= − 4.637,
p
< 0.001). Top three barriers for supplement use were forgetfulness (
n
= 118; 29.4%), too expensive (
n
= 91; 22.6%), and experiencing side effects (
n
= 61; 15.2%).
Conclusion
Lifelong nutritional supplementation is essential after bariatric surgery, but compliance can be affected by the presence of barriers.
Graphical abstract
PDF
