Empirical Envelopes Research Articles

A numerical investigation of the role of basements on tunnel-frame interaction in sandy soil

This paper investigates the role of basement depth on the response of framed buildings to tunnel construction in sandy soil using finite element modelling. Six frames are considered to explore the influences of tunnel cover depth, building width, eccentricity, and the number of storeys on the role of basement depth. The numerical models adopt the hypoplastic constitute model to simulate the behaviour of the sand. The results suggest that basement depth plays an important role in determining the settlements of the raft foundations and soil displacements due to tunnelling. Its effect on the structural shear distortion primarily depends on the ratio of tunnel depth to building width (C/B); an increase in basement depth decreases and increases building maximum shear distortion for C/B<0.3 and for C/B>0.35, respectively. The basement considerably increases the shear distortion of short eccentric structures by preventing tilt of the building, causing a divergence from existing empirical envelopes and modification factors for shear distortion. The applicability of the meta-model is extended to the embedded structures by linking the building tilt freedom coefficient with the basement depth parameter, achieving good agreement between the predicted results and calculated data. Limitations and practical implications of the research are briefly discussed.

ISM Analysis, Evolution, Human-type and Validation of UV–Spectrophotometric Techniques for Assessment of Sulfadiazine in Bulk and Cream Dose Forms

A CONVENTIONAL, precise, clear colorimetric technique that is additionally sensitive is evaluated for the appreciation of sulfadiazine medicine as a sharp form, as well as for different sorts of pharmaceutical products with different doses. The technique is premised on the conjugation of Sulfadiazine (SUZ) antibiotic as well as the 3,5Di hydroxy benzoic acid (3,5DHB) agent with utilizing the azo coupling reaction. The (3,5DHB) in the basic media to finally produce a ligand that interacts with Cobalt (II) to generate the strength orange complex color at room temperature. The associated outcomes dye is having a solubility in water as well as flexible additionally predestined colorimetrically with ultimate absorption at (436nm). The calibration graph between the absorbance and the concentration appears that the concentration range from medicine was established with utilizing the Beer’s law was between (0.12 - 18 μg/ml). The eclecticism of the best empirical envelopes is tested. The accuracy additionally the precision for the procedure are calculated by the average recovery amounts (100.122%) as well as the main relative standard deviation amounts (0.762 %) reasonably. That the technique is established on the concentration. The Sensitiveness for the procedure is obtained with molar absorptivity (2.24×104 lcm-1.mol-1). the Sandell sensitivity is tested ( 0.01 μg.cm-2). The analysis facts for The technique. It is agreed upon by the official procedure. The common medicinal additive intervention has been checked. The established technique is analyzed successfully in assessing (SUZ) in various types of pharmaceutical products .The antibacterial effectiveness capability of three different company sulfadiazine creams toward eight multidrug-resistant bacteria, the findings show that three creams with sulfadiazine had better antibacterial activity on A. Bacterial baumanii isolated as contrasted with another isolated. As for the effectiveness of sulfadiazine, they typically have high antibacterial activity on G-ve bacteria as contrasted to to G +ve bacteria, where Silverdin cream had higher biological efficacy on all bacterial isolates opposed to another creams, and Silverdin’s efficacy equally to pure Sulfadiazine’s antibacterial activity opposed to other two creams.

Charts for the mining-induced deflection of buildings

This study investigates the flexural deformations of buildings induced by mining-related subsidence. A two-stage solution (previously applied to the tunnelling problem) is used. Buildings are modelled as a beam founded on an elastic continuum that is subjected to ground subsidence. A tensionless soil–structure interface is employed. The effects of both building stiffness and self-weight on the building deflection are considered. The proposed formulation is compared with analytical solutions and empirical envelopes from previous research. A parametric study is conducted for both perfect soil–foundation bond and gap formation to relate deflection ratio modification factors and the limit radius of the greenfield settlement curve (associated with the gap formation) to relative structure–soil stiffness, building weight, foundation shape, and greenfield ground curvature (hogging or sagging) by means of dimensionless groups. Finally, a simple case study is used to demonstrate the proposed procedure. The given framework is more comprehensive than design charts provided by previous mining-related works and can be used for rapid preliminary risk assessment.

Threshold of motion and settling velocities of mollusc shell debris: Influence of faunal composition

AbstractBioclastic particles derived from mollusc shell debris can represent a significant fraction of sandy to gravelly sediments in temperate and cool‐water regions with high carbonate productivity. Their reworking and subsequent transport and deposition by waves and currents is highly dependent on the shape and density of the particles. In this study, the hydrodynamic behaviour of shell debris produced by eight mollusc species is investigated for several grain sizes in terms of settling velocity (measurements in a settling tube) and threshold of motion under unidirectional current (flume experiments using an acoustic profiler). Consistent interspecific differences in settling velocity and critical bed shear stress are found, related to differences in shell density, shell structure imaged by scanning electron microscopy and grain shape. Drag coefficients are proposed for each mollusc species, based on an interpolation of settling velocity data. Depending on the shell species, the critical bed shear stress values obtained for bioclastic particles fall within or slightly below empirical envelopes established for siliciclastic particles, despite very low settling velocity values. The results suggest that settling velocity, often used to describe the entrainment of sediment particles through the equivalent diameter, is not a suitable parameter to predict the initiation of motion of shell debris. The influence of the flat shape of bioclastic particles on the initiation of motion under oscillatory flows and during bedload and saltation transport is yet to be elucidated.

Intrinsic Fourier Mode Functions

In this paper, we study a class of functions that exhibit properties expected from intrinsic mode functions. A type of an empirical instantaneous frequency, depending on the extrema scale, is introduced and its proximity to the classical analytic instantaneous frequency is discussed. We also obtain a sufficient condition for positiveness of the instantaneous frequency and introduce a method similar in nature to EMD but with an empirical frequency as guide in lieu of empirical envelopes. The method is illustrated in several numerical examples.

Leaf density-based modelling of phototropic crown dynamics and long-term predictive application to European beech

The landscape of functional–structural tree growth models is divided into small-scale models with a topological architecture, and large-scale models based on a description of crown shape in terms of rigid structures such as empirical crown envelopes. Due to their computational heaviness, the former meet their limits in the simulation of old and large trees, whereas the latter are unable to allow for unrestricted spatial variability and plasticity. This article presents a mechanistic, spatially explicit tree growth model based on the characterisation of the spatial distribution of foliage in terms of the 3D leaf area density. This allows efficient and robust simulations while avoiding the complexity of branch topology and any a priori shape constraints. A key element of our model is the spatial expansion of the crown along the local light gradient or, in an equivalent teleonomic interpretation, in the optimal direction with respect to future biomass production. The calibrated model accurately predicts long-term growth dynamics for 16 stands of European beech (Fagus sylvatica L.), a species known to be particularly plastic. It generates complex properties in conjunction with crown shape, response to stand density, height dynamics and, in particular, the emergence of the allometric 3/4-rule. Simulation results motivate hypotheses on the weight of phototropism as one driver of the spatial growth of European beech in early and late stages as well as in and off competition.

Innovations in Regional Computable General Equilibrium (CGE) Modelling

With the emergence of regional computable general equilibrium (CGE) models in the later 1980s, there was significant optimism that they would greatly push economic policy and the empirical envelopes. Unlike partial equilibrium approaches or input–output methods, CGE models can trace the impact of an economic shock or policy shock through the various sectors, allowing estimates of changes in factors, output and prices. However, many of the first generation of CGE models had a ‘black box’ feel to them. Their results could be sensitive to the functional form, parameter estimates, and assumptions about capital and labour flows. For example, in their survey article, Partridge and Rickman (1998)11. Partridge, M. D. and Rickman, D. S. 1998. Regional computable general equilibrium modeling: a survey and critical appraisal. International Regional Science Review , 21: 205–250. [CrossRef], [Web of Science ®], [CSA] View all references called on CGE modellers to account for these problems and strive to produce more credible results. In recent years, regional CGE modellers have improved their approaches, producing innovative techniques to apply to real world problems.

Inversion of the high-frequency source radiation of M6.8 Avachinsky Gulf, Kamchatka, earthquake using empirical and theoretical envelope Green functions

We study the generation of high-frequency S-wave energy from its source of the 1992 Avachinsky Gulf, Kamchatka, earthquake (M W = 6.8) by means of the envelope inversion method of Nakahara et al. (1998). Two versions of this technique were employed, the original version and the modified version. In the modified version, to construct the “envelope Green function” we use empirical envelope shapes, constructed by averaging data of small earthquakes from the same area, calibrated to the total energy of the theoretical envelopes. The envelope inversion procedure was applied to six mainshock records, producing estimates of spatial distribution of energy radiation in frequency bands: 1–2, 2–4, 4–8 and 8–16 Hz. In both inversions, the distribution of energy radiation shows a similar pattern: 75–90 percent of the energy was radiated soon after nucleation. Afterwards, the rupture propagated mostly in a westward direction. Similarity of both results demonstrates the robustness of the envelope inversion method. However the version of the inversion procedure that uses empirical envelopes yields more plausible characteristics of the rupture process.

The computation of deterministic bounds to multiplexed MPEG video traffic using z‐characterization

AbstractIn this paper, we propose a method called z‐characterization for computing the deterministic bounds of an aggregated MPEG stream at frame level. Traditional deterministic characterization methods like empirical envelope generally suffer from the drawback of high computation complexity. In our approach, the I, P and B sub‐traces of an MPEG trace will be characterized independently such that they possess their own empirical envelopes. By exploiting the periodic group‐of‐pictures (GOP) structure of MPEG video, the I, P and B sub‐envelopes can act as building blocks for computing the characterization of the aggregate stream in real‐time. Experimental results show that our proposed characterization closely bounds the empirical envelope in both homogenous and heterogeneous multiplexing scenarios. Copyright © 2004 John Wiley &amp; Sons, Ltd.

Mechanical behaviour and failure mode of bentheim sandstone under triaxial compression

Hydrostatic and triaxial compression tests have been conducted on nominally dry samples of Bentheim sandstone, a homogeneous quartz-rich sandstone with porosity of about 23%. A broad range of confining pressures were used to observe the transition from the brittle faulting to cataclastic flow regime. Mechanical data for the brittle strength and compactive yield stress can be fitted with empirical envelopes that have been shown to be applicable to other porous sandstones. However, the Bentheim sandstone is somewhat unusual in that quasiductile failure (characterized by an overall hardening trend punctuated by episodic strain softening and compaction band formation) was observed over a wide range of confining pressures from 120 MPa to 300 MPa. Since this failure mode is similar to observations in honeycombed cellular solids, it is speculated that the prevalence of quasiductile failure in the Bentheim sandstone arises from its relatively homogeneous mineralogy and grain size. Compaction band formation may be inhibited in other sandstones with higher fractions of feldspar and clay, as well as more disperse grain sizes.