Global Structural Analysis Research Articles

THE AIM OF POLITICAL SYSTEM IN AFRICA

A growing trend in contemporary development research is to define development not only in economic terms but also as freedoms and capacities that individuals have to improve their social and economic standing (Pereira and Teles, 2010). While economic growth is crucial to sustained poverty reduction, institutional and social changes are also essential to the development processes and the inclusion of poor people (World Bank 2012). At the same time, themes of political stability and corruption have called for an analysis of global and national political structures and of their impact on socio-economic relationships(Acemoglu, 2012).

Application of the polynomial chaos method in global sensitivity analysis of trimaran cross-deck structure

An efficient global sensitivity analysis method based on the Polynomial Chaos (PC) method is applied to investigate the strength of a trimaran cross-deck structure. The PC method can reduce the amount of computation and converge faster than the Monte Carlo (MC) method. For the quantitative investigation of the sensitivity of the stresses in the cross-deck to the changes in the cross-deck plate thickness, Latin Hypercube Sampling (LHS) was used to obtain samples, and a Finite Element Method (FEM) model was used to compute the stress based on a load case prescribed by the Rules for the Classification of Trimarans. The PC surrogate models of different degrees of polynomial were trained and validated from the perspective of bias and variance. The third-degree PC model was selected to approximate the response of the stresses to the plate thickness. The global sensitivity indices were computed on the basis of the PC surrogate model, and the results were compared with those obtained by MC. The third-degree PC surrogate model effectively approximates the response of the stresses to the plate thickness, and the sensitivity indices of PC converges much faster than those of MC with respect to the number of samples. The stress at the corner of the cross-deck is the most sensitive to the thickness of the aft web. Meanwhile, the stress at the main-hull connection is the most sensitive to the thickness of the lower panel. Furthermore, the maximum von Mises stress and shear stress at the side-hull connection are the most sensitive to the thickness of the upper panel, and the maximum principal stress at the side-hull connection is the most sensitive to the thickness of the lower panel. The feasibility and efficiency of the PC method is proven, and the influence of the plate thickness on the stress response is described quantitatively.

Temperature behaviors of an arch bridge through integration of field monitoring and unified numerical simulation

Varying temperature may cause a non-uniform temperature distribution of a bridge and lead to excessive movement and stresses of the structure. Traditional thermal analyses of bridges adopt a divide-and-conquer approach, which conducts a simplified 2D or local 3D heat-transfer analysis and then a global 3D structural analysis by inputting the calculated temperature into another bridge model. This process requires considerable manual intervention and is inefficient and may lead to inaccurate results. This study develops a unified approach of heat-transfer and structural analyses for the first time to calculate the temperature distribution and the associated responses of an entire structure by integrating the field monitoring data. The arch footbridge at the Hong Kong Polytechnic University is used as a testbed, and a detailed finite element model (FEM) of the bridge is established. The measured air temperature and solar radiation are used as the thermal boundary conditions. The hemisphere technique is adopted to calculate the view factor between different surfaces of the bridge, which are then used to obtain the solar radiation on all external surfaces in different instants on different dates. The 3D global hear-transfer analysis is conducted to obtain the temperature distribution of the entire bridge. The calculated temperature data of the bridge are then automatically input into the same FEM of the bridge to calculate the temperature-induced bridge responses via the structural analysis. The heat-transfer analysis and structural analysis share the same FEM while using different element types. Therefore, the manual intervention is avoided. The calculated and monitored temperature data and responses show a good agreement. The developed new unified approach enables an automatic and efficient analysis of thermal behaviors of bridges. This approach can be extended to other types of bridges.

Quantitative Structural Proteomics Unveils the Conformational Changes of Proteins under the Endoplasmic Reticulum Stress.

Protein structures are decisive for their activities and interactions with other molecules. Global analysis of protein structures and conformational changes cannot be achieved by commonly used abundance-based proteomics. Here, we integrated cysteine covalent labeling, selective enrichment, and quantitative proteomics to study protein structures and structural changes on a large scale. This method was applied to globally investigate protein structures in HEK293T cells and protein structural changes in the cells with the tunicamycin (Tm)-induced endoplasmic reticulum (ER) stress. We quantified several thousand cysteine residues, which contain unprecedented and valuable information of protein structures. Combining this method with pulsed stable isotope labeling by amino acids in cell culture, we further analyzed the folding state differences between pre-existing and newly synthesized proteins in cells under the Tm treatment. Besides newly synthesized proteins, unexpectedly, many pre-existing proteins were found to become unfolded upon ER stress, especially those related to gene transcription and protein translation. Furthermore, the current results reveal that N-glycosylation plays a more important role in the folding process of the tertiary and quaternary structures than the secondary structures for newly synthesized proteins. Considering the importance of cysteine in protein structures, this method can be extensively applied in the biological and biomedical research fields.

Population structure of 3907 worldwide pigs and the introgression of Chinese indigenous pigs by European pigs.

With the improvement in sequencing technology and the decrease in sequencing cost, increasing amounts of genomic data for pigs have been uploaded to public databases. However, no researchers have to date integrated all currently available data to uncover the global genetic status of pigs. Meanwhile, little is known about the introgression from European to Chinese pigs and its underlying influences. Therefore, we integrated the effective genotype data of 3907 pigs from 193 populations worldwide using population genetic analysis, gene flow analysis and a sharing-IBD study. These findings illustrate not only the population structure of 59 Chinese native breeds and others but also the amounts of gene flow and introgression that have occurred between Western and Chinese pigs. In addition, we demonstrate the presence of introgressed European haplotypes in Chinese indigenous breeds and identify relevant introgressed regions that contain genes associated with growth and feed efficiency. Moreover, we compare the introgression patterns of Western and Chinese pigs and further discuss possible explanations for why the level of introgression differs between Chinese pig breeds and Western modern breeds. Collectively, this study provides a fine global population structure analysis of pigs and presents evidence of European pigs being interbred with local breeds in China.

Understanding fluorine-free electrolytes via small-angle X-ray scattering

Fluorine-free electrolytes have attracted great attention because of its low-cost and environmental friendliness. However, so far, little is known about the solution structures of these electrolytes. Here, we compare the solvation phenomenon of sodium tetraphenylborate (NaBPh4) salt dissolved in organic solvents of propylene carbonate (PC), 1,2-dimethoxyethane (DME), acetonitrile (ACN) and tetrahydrofuran (THF). Small-angle X-ray scattering (SAXS) reveals a unique two-peak structural feature in this salt-concentrated PC electrolyte, while solutions using other solvents only have one scattering peak. Molecular dynamics (MD) simulations further reveal that there are anion-based clusters in addition to the short-range charge ordering in the concentrated NaBPh4/PC electrolyte. Raman spectroscopy confirms the existence of considerable contact ion pairs (CIPs). This work emphasizes the importance of global and local structural analysis, which will provide valuable clues for understanding the structure-performance relationship of electrolytes.

Drivers of global nitrogen emissions

Nitrogen is crucial for sustaining life. However, excessive reactive nitrogen (Nr) in the form of ammonia, nitrates, nitrogen oxides or nitrous oxides affects the quality of water, air and soil, resulting in human health risks. This study aims to assess the drivers of Nr emissions by analysing six determinants: nitrogen efficiency (Nr emissions per unit of production), production recipe (inter-sectoral dependencies), final demand composition (consumption baskets of households), final demand destination (consumption vs. investment balance), affluence (final consumption per capita) and population. To this end, we construct a detailed multi-regional input-output database featuring data on international trade between 186 countries to undertake a global structural decomposition analysis of a change in global Nr emissions from 1997 to 2017. Our analysis shows that nitrogen efficiency has improved over the assessed time-period, however affluence, final demand destination and population growth have resulted in an overall increase in Nr emissions. We provide a global perspective of the drivers of nitrogen emissions at a detailed country level, and breakdown the change in emissions into contribution from domestic footprint and rest-of-world footprint. We highlight that food production coupled with growing international trade is increasing Nr emissions worldwide.

CO2 mitigation through global supply chain restructuring

This study develops an integrated analysis framework, called scenario-based extraction method (SEM) using four different input-output methods—unit structure analysis, cluster analysis, extended global extraction analysis and structural decomposition analysis. For the empirical analysis, we used the latest 2014 World Input–Output Database and modeled the global supply chain (GSC) CO2 network structure induced by the final demand for one relevant industry in one relevant country (the Japanese automobile industry in this study). The cluster analysis based on the GSC network data revealed CO2 emission-intensive clusters existed in this network with overconcentrated CO2 emissions outside of Japan. From the SEM analysis, we also found that the restructuring of the Japanese automotive supply chain based on extracting the largest CO2 emission cluster (i.e., CO2 emission hotspot) reduces its global carbon footprint by 6.5%. Simultaneously, the restructuring increases CO2 emissions in all countries other than a hotspot country, particularly in some important locations for the substitute production. We conclude that Japan's current automotive supply chain can significantly reduce CO2 emissions through structural reforms. Our framework can help in designing appropriate policies for restructuring green supply chains.

LinearTurboFold: Linear-time global prediction of conserved structures for RNA homologs with applications to SARS-CoV-2

The constant emergence of COVID-19 variants reduces the effectiveness of existing vaccines and test kits. Therefore, it is critical to identify conserved structures in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomes as potential targets for variant-proof diagnostics and therapeutics. However, the algorithms to predict these conserved structures, which simultaneously fold and align multiple RNA homologs, scale at best cubically with sequence length and are thus infeasible for coronaviruses, which possess the longest genomes (∼30,000 nt) among RNA viruses. As a result, existing efforts on modeling SARS-CoV-2 structures resort to single-sequence folding as well as local folding methods with short window sizes, which inevitably neglect long-range interactions that are crucial in RNA functions. Here we present LinearTurboFold, an efficient algorithm for folding RNA homologs that scales linearly with sequence length, enabling unprecedented global structural analysis on SARS-CoV-2. Surprisingly, on a group of SARS-CoV-2 and SARS-related genomes, LinearTurboFold's purely in silico prediction not only is close to experimentally guided models for local structures, but also goes far beyond them by capturing the end-to-end pairs between 5' and 3' untranslated regions (UTRs) (∼29,800 nt apart) that match perfectly with a purely experimental work. Furthermore, LinearTurboFold identifies undiscovered conserved structures and conserved accessible regions as potential targets for designing efficient and mutation-insensitive small-molecule drugs, antisense oligonucleotides, small interfering RNAs (siRNAs), CRISPR-Cas13 guide RNAs, and RT-PCR primers. LinearTurboFold is a general technique that can also be applied to other RNA viruses and full-length genome studies and will be a useful tool in fighting the current and future pandemics.

Long-read sequencing to interrogate strain-level variation among adherent-invasive Escherichia coli isolated from human intestinal tissue.

Adherent-invasive Escherichia coli (AIEC) is a pathovar linked to inflammatory bowel diseases (IBD), especially Crohn’s disease, and colorectal cancer. AIEC are genetically diverse, and in the absence of a universal molecular signature, are defined by in vitro functional attributes. The relative ability of difference AIEC strains to colonize, persist, and induce inflammation in an IBD-susceptible host is unresolved. To evaluate strain-level variation among tissue-associated E. coli in the intestines, we develop a long-read sequencing approach to identify AIEC by strain that excludes host DNA. We use this approach to distinguish genetically similar strains and assess their fitness in colonizing the intestine. Here we have assembled complete genomes using long-read nanopore sequencing for a model AIEC strain, NC101, and seven strains isolated from the intestinal mucosa of Crohn’s disease and non-Crohn’s tissues. We show these strains can colonize the intestine of IBD susceptible mice and induce inflammatory cytokines from cultured macrophages. We demonstrate that these strains can be quantified and distinguished in the presence of 99.5% mammalian DNA and from within a fecal population. Analysis of global genomic structure and specific sequence variation within the ribosomal RNA operon provides a framework for efficiently tracking strain-level variation of closely-related E. coli and likely other commensal/pathogenic bacteria impacting intestinal inflammation in experimental settings and IBD patients.

Structural strength evaluation of a 3000 dwt river-barge, under oblique quasi-static design waves

The present study consists of the 3D-FEM global structural analysis of a typical open-top, double-hull, 3000 DWT inland navigation barge, having 90 m in length. The 3D-FEM model developed to perform the evaluation idealizes the barge structure with high accuracy, average element size being in the range of 50-75 mm. Two loading cases were analyzed, consisting of the ballast and full loading conditions. For the equilibrium floating condition in calm water and oblique design waves, an eigen iterative scheme has been used to generate the input parameters for the 3D-FEM analyzed cases. The push-barge finite element model has been subjected to oblique quasi-static design waves, headings ranging from 0 to 75 degrees. Wave heights considered in the analysis range from 0 to 1.2 m, step 0.3 m, corresponding to the Danube navigation conditions and freeboard limit imposed by the classification societies for inland navigation vessels. Numerical results following the FE analysis have been assessed by the yielding stress ratio, von Mises criterion, and the maximum deformation, thus indicating the structural areas that need to be improved in the design process.

On the long-term hydroelastic global structural response evaluation of a 100000 tdw oil-tanker

In this paper, the hydroelastic analysis for a 100000 tdw oil-tanker, with a length of 240 m, operation reference speed of 15 knots, on two loading cases full cargo and ballast, is developed. For a realistic approach of the dynamic response, the oil-tanker is considered under random waves’ loads, requiring several steps in the process of the short-term and long-term global structural analysis. The random waves have Longuet-Higgins formulation, with first-order harmonics by ITTC power density spectrum, with maximum wave significant height 12 m, and second-order interference waves’ harmonics. The short-term hydroelastic analysis includes the linear response by frequency-domain solutions, the non-linear response by time-domain solutions, the global strength significant response by FFT Fast Fourier Transformation spectral approach. The long-term analysis includes the hydroelastic global strength assessment for Word Wide Trade averaged wave’s height histogram, the fatigue hull structure evaluation, over a 25 years exploitation reference time, applying the cumulative damage ratio approach. The stress hot-spot factors, up to 1.5, influence is considered. The oil-tanker model by own program DYN is developed, modules for hydroelastic response and statistical processing, applicable in any ship’s design stage, stressing out to the 100000 tdw oil-tanker long-term operation limits on the two relevant loading cases.

Generalized r-Lambert Function in the Analysis of Fixed Points and Bifurcations of Homographic 2-Ricker Maps

This paper aims to study the nonlinear dynamics and bifurcation structures of a new mathematical model of the [Formula: see text]-Ricker population model with a Holling type II per-capita birth function, where the Allee effect parameter is [Formula: see text]. A generalized [Formula: see text]-Lambert function is defined on the 3D parameters space to determine the existence and variation of the number of nonzero fixed points of the homographic [Formula: see text]-Ricker maps considered. The singularity points of the generalized [Formula: see text]-Lambert function are identified with the cusp points on a fold bifurcation of the homographic [Formula: see text]-Ricker maps. In this approach, the application of the transcendental generalized [Formula: see text]-Lambert function is demonstrated based on the analysis of local and global bifurcation structures of this three-parameter family of homographic maps. Some numerical studies are included to illustrate the theoretical results.

Interaction of geometric and material nonlinearities in stainless steel frames

AbstractAdequate mechanical properties make stainless steel an excellent construction material for structures. The current stainless steel European structural code EN1993‐1‐4 (2015) is largely based on provisions given for carbon steel EN1993‐1‐1 (2005) and does not establish specific design rules for the global analysis of stainless steel structures. Thus, the same classification criterion applies in both codes for sway and non‐sway structures, as well as providing the same predicting expressions for the amplification of bending moments in basic structures, despite the considerable differences between the mechanical behaviour of these two materials. However, recent numerical research on stainless steel frames with H cross‐sections by Walport et al. (2019) showed that the degradation of stiffness due to material nonlinearities considerably affects the response of stainless steel frames, causing greater deformations and increasing second order effects.In order to contribute to the optimal design of stainless steel structures, this paper investigates the influence of the nonlinear material response of stainless steel alloys on frame‐type structures with Rectangular Hollow Sections based on the experimental results conducted by Arrayago et al. (2019), and the interaction of material and geometric nonlinearities.

The Analysis of Current Global Governance Structure and Challenges of G7 Based on the G7 Foreign and Development Ministers’ Meeting 2021

The Analysis of Current Global Governance Structure and Challenges of G7 Based on the G7 Foreign and Development Ministers’ Meeting 2021

Experimental field study of floater motion effects on a main bearing in a full-scale spar floating wind turbine

In this paper we present a full-scale experimental field study of the effects of floater motion on a main bearing in a 6 MW turbine on a spar-type floating substructure. Floating wind turbines are necessary to access the full offshore wind power potential, but the characteristics of their operation leave a gap with respect to the rapidly developing empirical knowledge on operation of bottom-fixed turbines. Larger wind turbines are one of the most important contributions to reducing cost of energy, but challenge established drivetrain layouts, component size envelopes and analysis methods. We have used fibre optic strain sensor arrays to measure circumferential strain in the stationary ring in a main bearing. Strain data have been analysed in the time domain and the frequency domain and compared with data on environmental loads, floating turbine motion and turbine operation. The results show that the contribution to fluctuating strain from in-plane bending strain is two orders of magnitude larger than that from membrane strain. The fluctuating in-plane bending strain is the result of cyclic differences between blade bending moments, both in and out of the rotor plane, and is driven by wind loads and turbine rotation. The fluctuating membrane strain appears to be the result of both axial load from thrust, because of the bearing and roller geometry, and radial loads on the rotating bearing ring from total out-of-plane bending moments in the three blades. The membrane strain shows a contribution from slow-varying wind forces and floating turbine pitch motion. However, as the total fluctuating strain is dominated by the intrinsic effects of blade bending moments in these turbines, the relative effect of floater motion is very small. Mostly relevant for the intrinsic membrane strain, sum and difference frequencies appear in the measured responses as the result of nonlinear system behaviour. This is an important result with respect to turbine modelling and simulation, where global structural analyses and local drivetrain analyses are frequently decoupled.

Global analysis of nuclear cluster structure from the elastic and inclusive electron scattering

Background: Recently, the researches of cluster structure have attracted considerable attention. Many microscopic structure models have been applied to describe the cluster configurations.Purpose: To better analyze the cluster structure and associate with the experimental observations, comparative studies are carried out in this paper by combining the nuclear structure model with the electron scattering theory.Method: The density distributions for candidate nuclei of normal and cluster states are obtained from the deformed relativistic Hartree-Bogoliubov (RHB) model. Using some moderate approximations, the corresponding Coulomb form factors $|{F}_{C}{(q)|}^{2}$ and inclusive cross sections for different configurations are calculated by the distorted wave Born approximation (DWBA) and coherent density fluctuation model (CDFM), respectively.Results: Comparing the $|{F}_{C}{(q)|}^{2}$ and inclusive cross sections of different configurations, the effects of nuclear cluster structure can be revealed, due to the differences of nuclear charge radii ${R}_{C}$ in coordinate space and the discrepancies of Fermi momentum ${k}_{F}$ in momentum space.Conclusions: Results illustrate that the cluster structure can be reflected from the elastic and inclusive electron scattering. The studies conducted in this paper provide a new approach to analyze the cluster configurations, and are also helpful to guide future electron scattering experiments.

Global Analysis of Stage Structure Two Predators Two Prey Systems Under Harvesting Effect for Mature Predators

This article examines set a prey-predator population model system with structural stages. Development of a mathematical model of a sustainable population of a population of living things. Structure stages are formed in predator populations, namely immature and mature. The predation function that corresponds to the characteristics in the ecosystem is the predation process of Holling I. The interaction in the population model that is carried out analysis is the equilibrium value formed from the population model. There are eight equilibrium values that arise from simple simulations. The equilibrium is E 1(0,0,0,0), E 2(0, k,0,0), E 3(k,0,0,0), E 4(k, k,0,0), E 5(0,0,0, A 1), E 6(A 2,0, A 3, A 4), E 7(0, A 5, A 6, A 7) and E 8(A 8, A 9, A 10, A 11). However, only one equilibrium value is analyzed to obtain stability. Stability is seen by requiring four eigenvalues with the Jacobian matrix. As well as the chosen value is used to find the amount of harvest carried out. The linearization of differential equations is an alternative way in this study to obtain equilibrium values. Each equilibrium value has the characteristics and terms of its stability. The Routh-Hurwitz criterion becomes a condition of its stability characteristics. Meanwhile, exploitation efforts in the population are carried out to see the changes that occur. Harvesting carried out obtained harvesting business W = 0.01313666667. For the maximum benefit obtained π = 4.997259008. This advantage is the stability and sustainability of the ecosystem.

Research on Seismic Test and Calculation Model for Improving Factor of Composite Board with Heat Preservation Function

Since the composition and stress state of thermal-insulation composite plates are extremely complex, it is difficult to conduct calculation using conventional methods. Further calculation on its composition structure is even more difficult. To settle this difficulty, this paper conducted experimental investigations on thermal-insulation composite plate and conventional composite plates, and a simplified calculation method with improved factors was deduced based on the experimental results. In this study, the influence of nonstructural thermal insulation system on the composite plate was specially considered. The calculated expressions are deduced, while the stiffness and damping (properties) are determined. Case analysis was carried out to validate the reliability and accuracy of the simplified calculation method of improvement factor. The research results indicate that the modeling difficulty and computational effort are greatly reduced, with relatively small errors. Hence, it is beneficial to the calculation and analysis of composite plates and global structures.

A comprehensive analytical model for global buckling analysis of general grid cylindrical structures with various cell geometries

In this paper, we present an analytical method based on equivalent continuum homogenization for the global buckling analysis of the general grid lattice cylindrical structures. In the proposed scheme, grid structures with arbitrary cell geometries can be analyzed by obtaining their effective cell stiffness based on force and moment analysis of the struts. The grid structures are assumed to be composed of curvilinear axial, circumferential, and oblique unidirectional composite ribs. To evaluate the results of the presented analytical method, a parametric finite element code is derived to generate the desired geometry of the grid structures and their buckling loads are obtained and compared with the analytical method. The effects of various parameters, including the number of ribs, their thickness and elastic properties, and helical angle of the oblique ribs are studied for hexagonal, triangular, and mixed grid shells. The results are compared with the available data published in the literature with a good agreement.