SM Model Research Articles

Presupernova Evolution and Explosive Nucleosynthesis of Rotating Massive Stars. II. The Supersolar Models at [Fe/H] = 0.3

We present an extension of the set of models published in Limongi & Chieffi (2018) at metallicity 2 times solar, i.e., [Fe/H] = 0.3. The key physical properties of these models at the onset of core collapse are mainly due to the higher mass loss triggered by the higher metallicity: the supersolar metallicity (SSM) models reach core collapse with smaller He- and CO-core masses, while the amount of 12C left by the central He burning is higher. These results are valid for all the rotation velocities. The yields of the neutron-capture nuclei expressed per unit mass of oxygen (i.e., the X/O) are higher in the SSM models than in the SM ones in the nonrotating case, while the opposite occurs in the rotating models. The trend shown by the nonrotating models is the expected one, given the secondary nature of the neutron-capture nucleosynthesis. Vice versa, the counterintuitive trend obtained in the rotating models is the consequence of the higher mass loss present in the SSM models, removes the H-rich envelope faster than in the SM models while the stars are still in central He burning, dumping out the entanglement (activated by the rotation instabilities) and therefore conspicuous primary neutron-capture nucleosynthesis.

Coupled Calculation of Soil Moisture Content and PML Model Based on Data Assimilation in the Hetao Irrigation District

Most Penman-Monteith-Leuning (PML) evapotranspiration (ET) modeling studies are dominated by consideration of meteorological, energy, and land use information, etc., but the dynamic coupling of soil moisture content (SM), especially in terms of improving accuracy through assimilation, lacks sufficient attention. This paper proposes a research framework for the dynamic coupling simulation of PML model and SM based on data assimilation, i.e., the remote sensing monitored SM is combined with soil evaporation of PML to obtain high-precision time-continuous SM data through data assimilation; simultaneously, dynamical soil evaporation coefficients are generated based on the assimilated SM to improve the simulation accuracy of the PML model. The new scheme was validated at a typical irrigation zone in north China and showed obvious improvements in both SM and ET simulations. Moreover, the effect of the assimilation of SM on the simulation accuracy of ET for different crop growth periods is further analyzed. This research provides a new idea for the coupling simulation of the SM and PML models.

Strategic promotion decisions of competing mobile application suppliers in Stackelberg game context

This paper considers a marketplace coexisting a brand mobile application supplier and an ordinary one providing customers with substitutable software service. The two suppliers can either promote the software individually (SP strategy) or resort to the downstream distributor (MP strategy) to achieve higher market demand. Taking the downstream distributor’s revenue sharing behavior and the demand expansion effect of MP strategy into consideration, we build a two-stage Stackelberg game model to explore the suppliers’ equilibrium promotion and pricing decisions. Through analysis, we obtain the following significant conclusions and managerial implications. Firstly, both suppliers would price highest in MM model. Secondly, the brand supplier prices higher in MS model than that in SM model while the ordinary supplier prices higher in MS model than that in SM model only when the brand difference between two suppliers is sufficiently high. Thirdly, when the demand expansion effect of MP strategy and the brand difference between two suppliers are both relatively low, SS may become the equilibrium no matter how high the revenue retaining ratio is, which inspires the suppliers in application supply chain to think outside the box. That is, it is not always beneficial to choose MP strategy when the revenue retaining ratio is sufficiently high. Noticeably, the above conclusions remain robust in extended models. Finally, while SM would never be the unique equilibrium in simultaneous game, it can be the equilibrium in sequential game.

Diversity of seed storage behavior of tree species from tropical lowland rainforests in Sri Lanka, a global biodiversity hotspot

AbstractTropical lowland rainforests are considered to be ecologically important refugia of national and global significance, yet wide‐scale deforestation and degradation of tropical lowland rainforests lead to losses in biodiversity. Seed storage behavior information is required for the effective restoration of these forests. Here, we studied the seed storage behavior of 42 selected tropical lowland rainforest tree species from Sri Lanka with the aim to test the reliability of current experimental methods and predictive models to predict the desiccation sensitivity of seeds. Seed storage behavior was experimentally determined through the 100 seed method and the results were compared with three predictive models; thousand seed weight–moisture content (TSW–MC), seed coat ratio–seed mass (SCR–SM), and phylogenetic affiliation models. Based on the 100 seed method, 28 species were identified as desiccation sensitive and 14 species were identified as desiccation tolerant. Compared to the 100 seed method, the predictability of the SCR–SM model was 70%, whereas the TSW–MC and phylogenetic affiliation models showed 52% and 58% predictability, respectively. Due to its higher predictability, the SCR–SM model has a high potential to be an effective predictive tool of seed storage behavior. This study revealed that tropical lowland rainforests are dominated by trees producing desiccation‐sensitive seeds. Further, species dispersing seeds in the peak rainy season have desiccation‐sensitive seeds, while those dispersing seeds in the normal wet season have desiccation‐tolerant seeds. Another key finding was that 100% of the subcanopy species produce nonorthodox, that is, desiccation‐sensitive seeds, which gradually decrease from subcanopy to understory.

Accuracy of Structure-from-Motion/Multiview Stereo Terrain Models: A Practical Assessment for Applications in Field Geology

We assess the accuracy of Structure-from-Motion/Multiview stereo (SM) terrain models acquired ad hoc or without high-resolution ground control to analyze their usage as a base for inexpensive 3D bedrock geologic mapping. Our focus is on techniques that can be utilized in field projects without the use of heavy and/or expensive equipment or the placement of ground control in logistically challenging sites (e.g., steep cliff faces or remote settings). We use a Terrestrial Light Detection and Ranging (LiDAR) survey as a basis for the comparison of two types of SM models: (1) models developed from images acquired in a chartered airplane flight with ground control referenced by natural objects located on Google Earth scenes; and (2) drone flights with a georeference established solely from camera positions located by conventional, differentially corrected Global Navigation Satellite systems (GNSS). We find that all our SM models are indistinguishable in scale from the LiDAR reference model. The SM models do, however, show rigid body translations and rotations, with translations generally within the 1–5 m size of the natural objects used for ground control, the resolution of the GNSS receivers, or both. The rigid body rotations can be attributed to a poor imaging plan, which can be avoided with survey planning. Analyses of point densities in various models show a limitation of Terrestrial LiDAR point clouds as a mapping base due to the rapid falloff of resolution with distance. In contrast, SM models are characterized by relatively uniform point densities controlled by camera optics, the numbers of images, and the distance from the target. This uniform density is the product of the Multiview stereo step in SM processing that fills areas between key points and is important for bedrock geologic mapping because it affords direct interpretation on a point cloud at a relatively uniform scale throughout a model. Our results indicate that these simple methods allow SM model construction to be accurate to the range of conventional GNSS with resolutions to the submeter, even cm, scale depending on data acquisition parameters. Thus, SM models can, and should, serve as a base for high-resolution geologic mapping, particularly in a steep terrain where conventional techniques fail. Our SM models appear to provide accurate visualizations of geologic features over km scales that allow detailed geologic mapping in 3D with a relative accuracy to the decimeter or centimeter level and absolute positioning in the 2–5 m precision of GNSS; a geometric precision that will allow unprecedented new studies of any geologic system where geometry is the fundamental data.

Polarization of GRB prompt emission and its application to POLAR’s data

Synchrotron emission polarization is very sensitive to the magnetic field configuration. Recently, polarization of synchrotron emission with a mixed (SM) magnetic field in the gamma-ray burst (GRB) afterglow phase has been developed. Here, we apply these SM models to the GRB prompt phase and compare their polarization properties with that of synchrotron emission in purely ordered (SO) magnetic field. We find that the polarization properties in an SM model are very similar to these in a corresponding SO model (e.g., synchrotron emission in a mixed magnetic field with an aligned ordered part (SMA) and synchrotron emission with a purely ordered aligned magnetic field (SOA)), only with a lower polarization degree (PD). We also discuss the statistical properties of the models. We find PDs of the simulated bursts are concentrated around 25% for both SOA and synchrotron emission in a purely ordered toroidal magnetic field (SOT), while they can range from 0% to 25% for SMA and synchrotron emission in a mixed magnetic field with a toroidal ordered part (SMT), depending on ξB value, i.e., the ratio of magnetic reduction of the ordered magnetic field over that of random magnetic field. From statistics, if PDs of majority GRBs are non-zero, then it favors SO and SM models. Further, if there are some bright GRBs with prominently lower PDs than that of the majority GRBs, it favors SOT (SMT) models; if all the bright GRBs have comparable PDs with the majority ones, it favors SOA (SMA) models. Finally, we apply our results to POLAR’s data and find that ∼ 10% time-integrated PDs of the observed bursts favor SMA and SMT models, and the ξB parameter of these bursts is constrained to be around 1.135.

A comparative study on the difference of CFD simulations based on a simplified geometry and a more refined BIM based geometry

A strategy of the combination of Computational Fluid Dynamics (CFD) and Building Information Model (BIM) technology was proposed to evaluate the wind environment around a building with complex façades for green building assessment. The Science and Education Building located at the Emerald Lake Campus of the Hefei University of Technology in China was selected as a case study. Two modeling methods, refined modeling by BIM software (BIM model) and traditional simplified modeling by computer aided design software (simplified model, referred to as SM model), were considered. The differences between the CFD results from the two geometry models were carefully examined. Three typical outdoor activity areas were selected to study the wind velocity difference, including the central channel, roof garden, and overhead corridor. The pressure difference between the CFD simulation results of the BIM model and the SM model at the exterior windows of the high-rise building was compared and analyzed. The results show that when a narrow channel is formed between two buildings, the wind velocity of the BIM model at the channel will be significantly lower than that of the SM model. The large “wall-type” components of the building roof will enhance the vortex area. The average pressure difference is greater than 0.5 Pa at the external window of building façades, accounting for up to 39.6%. The maximum pressure difference is as high as 10.13 Pa. The wind velocity difference is as high as 2.65 m/s at the central channel, 4 m/s at the roof garden, and 3.69 m/s at the overhead corridor. These differences will significantly affect the evaluation of the outdoor wind environment in green building assessment.

Sub‐Mesoscales at Ocean Fronts: Dissipation of Eddy Kinetic Energy

AbstractD'Asaro et al. measured the dissipation of eddy kinetic energy at the Kuroshio ocean front, found it to be 1–2 orders of magnitude larger than the value predicted by the law of the wall, and suggested that the enhancement is due to sub‐mesoscales, SM. To assess their suggestion, we employ two SM models. In the first model, the buoyancy flux is based on baroclinic instabilities only and there is no momentum flux (Reynolds stresses). The model is unable to reproduce the Kuroshio data. The second model includes baroclinic instabilities, wind stress, and Reynolds stresses. It reproduces the data satisfactorily. The analytic formula for the dissipation that we present can be used in ocean general circulation models to parameterize dissipation at ocean fronts other than Kuroshio, for example, Gulf Stream and ACC, an extension that could improve the predictions of climate studies.

BSM contributions to the Zγγ and ZZγ self couplings at high energies

The CP conserving Zγγ and ZZγ couplings in the SM and MSSM models at loop level were investigated. For the both models, the coupling parameters , , were estimated for the energy ranges, accessible at the LHC. Extension of the considered energy range up to 14 TeV leads to a possibility to constrain theories by using experimental limits on anomalous couplings from the LHC experiments. It was found that in order to constrain the parameters of the MSSM model, a measurement accuracy of the order of 10−7 is required.

Effects of vector leptoquarks on decay

Experimental data on , , and , provided by different collaborations, show sizable deviations from the standard model predictions. To describe these anomalies, many new physics scenarios have been proposed. One of them is the leptoquark model, which introduces the simultaneous coupling of vector and scalar leptoquarks to quarks and leptons. To look for similar possible anomalies in the baryonic sector, we investigate the effects of a vector leptoquark on various physical quantities related to the tree-level decays ( ), which proceed via transitions at the quark level. We calculate the differential branching ratio, forward-backward asymmetry, and longitudinal polarizations of leptons and baryons at the and lepton channels in the leptoquark model and compare their behavior to the predictions of the SM in terms of . In the calculations, we use the form factors calculated in full QCD as the main input and account for all errors coming from the form factors and model parameters. We observe that at the channel, the fit solution to data related to the leptoquark model sweeps some regions out of the SM band; nevertheless, the fit has a considerable intersection with the SM predictions. The type solution gives roughly the same results as the SM on . At the channel, the leptoquark model gives results that are consistent with the SM predictions and existing experimental data on the behavior of with respect to . Concerning the behavior of the , the two types of fits for and the predictions at the channel in the leptoquark model give exactly the same results as the SM. We also investigate the behavior of the parameter with respect to and the value of in both the vector leptoquark and SM models. Both fit solutions lead to results that deviate considerably from the SM predictions for and . Future experimental data on and , made available by measurements of the channel, will be particularly helpful. Any experimental deviations from the SM predictions in this channel would emphasize the importance of tree-level hadronic weak transitions as good probes of new physics effects beyond the SM.

Subduction Polarity in Ancient Arcs: A Call to Integrate Geology and Geophysics to Decipher the Mesozoic Tectonic History of the Northern Cordillera of North America: REPLY

Subduction Polarity in Ancient Arcs: A Call to Integrate Geology and Geophysics to Decipher the Mesozoic Tectonic History of the Northern Cordillera of North America: REPLY

Strategy to enhance intrinsic ductility and surface stability of Mg-Zn-R (R = La to Sm) alloys from a first-principles study

The generalized stacking fault energies of the {0001}〈10–10〉, {1–100}〈11–20〉 and {11–22}〈11–23〉 slip systems and surface energies of {0001} surface are investigated on pure Mg, Mg-Zn and Mg-Zn-R (R = La to Sm) models, through first-principles calculations based on density functional theory. The results show that the addition of alloying element R enhances the intrinsic ductility of Mg-Zn alloys. Moreover, the effect of solute concentration on surface stability is examined by Mg-Zn-La model, and the result suggests that the surface becomes more stable with the decrease of solute concentration. Thereby, the formability and surface stability of Mg-Zn alloys can be modified by adding rare-earth elements R.

Modeling of Crucial Process Parameters for the Continuous Improvement of Special Steels at the Stomana Plant

In this study, a heat transfer model that takes under consideration the micro-segregation phenomena and has been extensively deployed for solidification studies concerning the plant casters is also applied to show the casting speed and superheat effects upon internal soundness. Τhe solidification path of C45R, 42CrMo4, S355 grades was simulated using Thermocalc® and DICTRA software in order to examine the phases formed in crucial process temperature windows for the casting. Coupled Heat Transfer/Simple Micro-Segregation Model software has been deployed to simulate the effect of cooling rate on solidus temperature, and solid fraction during solidification. The solidus temperature results computed by the HT/SM and DICTRA were found to be in good agreement. However, the differences in the predicted solidification fractions may derive from the fact that DICTRA uses an average cooling rate whereas the heat transfer SM model takes into account also the local cooling rates in the solidification progress.

Research on Logistics Route Optimization Based on GPS and GIS Technology

There are a lot of places to improve and develop in the management of the logistics industry. This paper that is according to the serious problems and shortcomings of logistics' delivery and management in the logistics industry makes full use of Internet + technology, GPS, GIS technology, large data analysis and other high-techs to design an innovative LDM software (Logistics Distribution Manager). Its function is to break the fixed distribution line mode, optimize the allocation of resources, automatically select the shortest distance, achieve same direction-routes delivery, break the provincial boundaries and achieve the nearest shunting. What's more, the paper is also combined with FRID technology (Radio Frequency Identification) to design a SM model (Smart Machine) that's about optimizing logistics sorting process. Both LDM software and SM model are systematically applied to the logistics industry to achieve the optimizing route of the logistics delivery, so that the logistics company can greatly shorten the time of logistics delivery to save operating costs and improve business efficiency. And this also can meet customers' needs in time and immensely ease the traffic pressure.

The Mu3e Experiment

The Mu3e experiment will search for lepton flavor violation in the neutrinoless muon decay μ+→e+e−e+ with a sensitivity down to 10−16 (90% C.L.) using the world most intense muon beam at the Paul Scherrer Institute. The μ+→e+e−e+ decay is strongly suppressed in the Standard Model whilst several Beyond the SM models predict observable effects accessible to the new generation of LFV experiments. The search for the μ+→e+e−e+ decay requires a large acceptance detector capable of measuring up to 2 × 109 decays of stopped muons per second with excellent momentum, space, and time resolution to suppress backgrounds below the 1016 level. The required Mu3e detector performance is possible thanks to tracking detectors based on thin monolithic active silicon pixel sensors (HV-MAPS) and very precise timing measurements using scintillating fibers and tiles both coupled to silicon photo-multipliers. The first phase of the Mu3e experiment has been recently approved. Following an intense R&D program the construction of the detector is about to start. First data taking is expected in 2019.

Effects of transcytolemmal water exchange on the assessment of myocardial extracellular volume with cardiovascular MRI.

Quantitative analysis of the myocardial interstitial space is gaining increased interest as a biomarker in the MRI and clinical cardiovascular communities. To investigate the effect of water exchange on the calculation of myocardial extracellular volume (ECV), we employed two tissue models: the standard ECV two-point model (SM) and the shutter speed model (SSM). Twenty individuals (18 men and two women; age 61.9 ± 10.3 years) underwent MRI at 1.5 T with pre-contrast and post-contrast dynamic T1 quantification. Means, standard deviations and ranges for SM and SSM model parameters were calculated. Infarct and viable myocardial model parameters as well as apparent ECV values calculated with the SM and SSM were statistically compared. Viable ECV(SM) remained temporally constant (27.3-28.0%: P = 0.5) and infarcted myocardial ECV(SM) changed significantly (49.3-58.8%; P < 0.001), reaching a steady-state value after 15 min. The intracellular lifetime of water was three times greater in infarcted myocardium when compared with viable myocardium (τi: 66.6 ± 115 versus 208.7 ± 72.7 ms) and accompanied a twofold increase in ECV (ECV(SSM) : 30.3 ± 11.1 versus 71.0 ± 13.1%; P < 0.001). There was a consistent significant difference in ECV values of infarcted myocardium at different timepoints between the SM and SSM, but not viable myocardium, presumably due to slower water exchange. In summary, we found a significant change in apparent ECV and water exchange in infarcted myocardium when compared with viable myocardium. This was visualized by changes in dynamic contrast enhanced curve shapes and quantified using the SSM as not only an increase in apparent ECV but also a decrease in water exchange.

A search for prompt lepton-jets in pp collisions at s = 8 $$ \sqrt{\mathrm{s}}=8 $$ TeV with the ATLAS detector

A search is presented for a new, light boson with a mass of about 1 GeV and decaying promptly to jets of collimated electrons and/or muons (lepton-jets). The analysis is performed with 20.3 fb$^{-1}$ of data collected by the ATLAS detector at the Large Hadron Collider in proton--proton collisions at a centre-of-mass energy of 8 TeV. Events are required to contain at least two lepton-jets. This study finds no statistically significant deviation from predictions of the Standard Model and places 95\% confidence-level upper limits on the contribution of new phenomena beyond the SM, incuding SUSY-portal and Higgs-portal models, on the number of events with lepton-jets.

Comparative analysis of theΛb→Λℓ+ℓ−decay in the SM, SUSY, and RS model with custodial protection

We comparatively analyze the rare $\Lambda _b\rightarrow \Lambda \ell^+ \ell^-$ channel in standard model, supersymmetry and Randall-Sundrum model with custodial protection (RS$_c$). Using the parametrization of the matrix elements entering the low energy effective Hamiltonian in terms of form factors, we calculate the corresponding differential decay width and lepton forward-backward asymmetry in these models. We compare the results obtained with the most recent data from LHCb as well as lattice QCD results on the considered quantities. It is obtained that the standard model, with the form factors calculated in light-cone QCD sum rules, can not reproduce some experimental data on the physical quantities under consideration but the supersymmetry can do it. The RS$_c$ model predictions are roughly the same as the standard model and there are no considerable differences between the predictions of these two models. In the case of differential decay rate, the data in the range $4 $ GeV$^2/$c$^4\leq$ $q^2 \leq 6$ GeV$^2/$c$^4$ can not be described by any of the considered models.

Anthropometric Models To Predict Body Segmented Mass Compared With DXA In Professional Football Soccer Players

PURPOSE: To compare anthropometric models to predict SM using DXA as the reference method. METHODS: 85 male professional football soccer players aged 19.9 ±4.7 years old were evaluated. Body weight, 10 skinfolds, 14 circumferences, 6 segments, 3 heights and 9 diameters were measured. DXA whole body scanning was performed with a Hologic QDR equipment. The DXA measurements were established as references to compare the anthropometric equations to predict SM. An ANOVA test was used with Dunnett’s test as post hoc, to find differences between each SM equation and total estimated body weight (SM sum) with DXA. RESULTS: None of the equations had differences in estimated body weight compared to the measured one. In the estimation per segment some had differences against DXA. All equations fail to estimate head mass. The thorax mass had no differences with Clauster and McConville equations. Barter’s equation had no differences in the upper limbs and Clauster with the lower limbs. Table 1 shows the results expressed as the differences between SM estimation and DXA. CONCLUSIONS: Using only one author’s model could lead to prediction errors in SM even if the sum of them had no differences against the measured body weight. This even happens when there is a combination of the most accurate equations for each SM. Although other mathematical models have been developed, their anthropometric measurements are not of common use. The development of new SM models should be encouraged to facilitate the study of the SM in athletes.Table: No title available.

Eventos extremos de precipitação no Alto Rio Grande, MG: Análise probabilística

As distribuições de probabilidades de valores extremos desempenham importante papel na modelagem de eventos extremos. Elas têm sido amplamente aplicadas em estudos hidrológicos a fim de predizer, para um nível de confiança, valores esperados num dado tempo de retorno. Várias distribuições têm sido empregadas com diferentes métodos de ajuste. Objetivou-se neste trabalho verificar a aderência das distribuições GEV e Gumbel aos dados de precipitação diária máxima anual de doze estações pluviométricas no Alto Rio Grande, MG. Foram consideradas três sub-regiões com características fisiográficas peculiares, cada uma com quatro estações pluviométricas em seus domínios, Planalto Campos das Vertentes (PCV), Serra da Mantiqueira (SM) e uma sub-região de Transição (TR) entre as duas. Para a estimação dos parâmetros utilizou-se o método dos momentos, máxima verossimilhança e momentos-L. A aderência dos ajustes foi avaliada pelos testes de Filliben e Qui-quadrado (χ2). A metodologia dos momentos-L mostrou-se como a melhor opção, independente da sub-região sendo que se recomenda, para as sub-regiões SM e TR, a distribuição Gumbel, enquanto para o PCV a melhor opção de ajuste é a GEV.