The Nambu–Jona-Lasinio model is known for its simplicity and capacity to reproduce some of the basic characteristics of the quantum chromodynamics phase diagram. However, since it is a nonrenormalizable model, there are regularization issues that should be treated conveniently. This is the case when considering the quark anomalous magnetic moment (AMM) when external constant magnetic fields are present. Regularization procedures based on entangled functions between the magnetic field and the cutoff of the model can predict first-order phase transitions for chiral symmetry restoration at finite values of magnetic fields and inverse magnetic catalysis. The strengths of magnetic fields explored in NJL model and lattice QCD do not show first-order phase transition. In the present work, we show that some of the previous results are regularization-dependent effects and how to handle the divergences using the vacuum magnetic regularization scheme. 相似文献
Slow-maintained static load tests were performed on closed-ended and open-ended steel pipe piles driven side by side in a gravelly sand soil profile. The site investigation consisted of multiple cone penetration tests (CPTs) and standard penetration tests (SPTs), as well as laboratory tests on soil samples collected at various depths from the test site to determine basic soil properties. The test piles were densely instrumented with a combination of electrical-resistance and vibrating-wire strain gauges. The open-ended test pile was a specially fabricated double-wall, fully-instrumented pile, allowing for separation of the measurements of the inner and outer shaft resistances. Detailed comparison of the load test results, in terms of driving resistance, load response and profiles of unit shaft and base resistances for the two test piles, is presented and discussed. The applicability of three CPT-based pile design methods is assessed through a layer-by-layer comparison of the estimated resistances with those measured in the static load tests.
In this article we present a geostatistical approach to the transmission tomographic inverse problem, which is based on consideration of the inverse problem variables (velocity and traveltime errors) as regionalized variables (R.V.). Their structural analysis provides us with a new method to study the geophysical anisotropy of the rock, an important source of a priori information in order to design the anisotropic corrections. The underlying idea is that the geophysical structure can be deduced from the spatial structure of the regionalized variables which result from solving the tomographic problem with an isotropic algorithm. Also, the application of the structural analysis technique to the anisotropic corrected velocity field allows us to characterize the reliability of these corrections (model quality analysis). Geostatistical formalism also provides us with different techniques (parametric and non-parametric) to estimate and even simulate the velocity in the areas where this field has been considered anomalous based on field studies and on geophysical and statistical criteria. The kriging acts as a low-pass smoothing filter for the anomalous model parameters (velocities), but is not a substitute for an adequate filtering of the outliers before the inversion. This methodology opens the possibility of considering the inverse problem variables as stochastic processes, an important feature in cases where the tomogram is to be used as a tool of assessment to quantify the rock heterogeneities. 相似文献
Tropical glaciers of the Cordillera Blanca, Perú are rapidly thinning and retreating as a result of climate warming. The retreat of these glaciers along narrow linear bedrock valleys has increased the number and size of moraine-dammed glacial lakes formed in the valleys. This study aims to identify the geomorphological and sedimentological characteristics of an enlarging moraine-dammed supraglacial lake (Llaca Lake) in the Cordillera Blanca. Field-based sedimentological observations and geomorphological mapping were combined with remotely sensed data and a photogrammetric model derived from aerial surveys by an uncrewed aerial vehicle to identify landform-sediment assemblages. The geomorphological and sedimentological characteristics of Llaca Lake are synthesized into three landsystem zones: Zone 1: distal portions of Llaca Lake and the latero-frontal moraine; Zone 2: the central zone of ice-cored hummocks; and Zone 3: the active glacier margin. These zones are differentiated based on the spatial distribution of landforms, sediments, and active geomorphological processes. This is the first study to describe the landform-sediment assemblages in a tropical moraine-dammed supraglacial lake system and provides a framework for further landsystem element analysis of these growing supraglacial lakes in rapidly deglaciating high-altitude environments. 相似文献
The conventional approach in the design of laterally loaded piles with rectangular cross section involves the simplification of converting the rectangular cross section of the pile to an equivalent circular cross section. An analysis to determine the response of laterally loaded rectangular or circular piles in elastic soil is presented in which this simplification is not required. The analysis is based on the solution of differential equations governing the displacements of the pile–soil system derived using energy principles. The pile geometry and the elastic constants of the soil and pile are the input parameters to the analysis. Using this analysis, comparisons are made between the response of rectangular and circular piles in elastic soil. Based on the proposed solution scheme, a user-friendly spreadsheet program (LATPAXL) was developed that can be used to perform the analysis. In addition, simple equations obtained by regression analysis of the pile head deflection and bending moment profiles are proposed. Examples illustrate the use of the analysis. 相似文献
The presence of lateritic soils occurs in tropical and subtropical regions. The improvement of lateritic soils that are not suitable for a particular purpose through techniques that combine modification of grain size through the insertion of sand, incorporation of Portland cement and densification through compaction is seen as an alternative. In this context, a dosage method to use a local lateritic soil as construction material in a most rational way reducing the economic and environmental impacts related to this activity is still missing. Therefore, the current research aims to evaluate the performance of a lateritic soil via modification of grain size through the insertion of sand, incorporation of Portland cement and densification through compaction. For this, unconfined compression, and durability (wetting and drying) tests were carried out on specimens of compacted clayey gravel lateritic soil, whose granulometry was modified by the insertion of distinct amounts (from zero to 45%) of weathered sand, treated with distinct Portland cement contents (from 4 to 10%), molded at different dry unit weights (from 16.8 to 20.1 kN/m3) and cured for 7 and 28 days. Results of the mechanical tests have shown the significant influence exerted by cement content and dry unit weight of the blend, followed by curing time and finally sand insertion. Satisfactory correlations between the response variables (qu and ALM) and the adjusted porosity/cement index (η/Cv) were obtained. Furthermore, an innovative approach to replacing the laborious durability test is proposed.
Natural Hazards - Due to Chile’s notorious and frequent seismic activity, earthquake- and tsunami-related studies have become a priority in the interest of developing effective... 相似文献