Part Of Structure Research Articles

Finite element modeling of the influence of FRP techniques on the seismic behavior of an arch stone bridge of historical interest

In this paper, a masonry bridge is simulated in order to assess both its structural and seismic vulnerability. Therefore, the present study aimed to approximately analyze the real behavior of Mikron Bridge structure. The modeling was conducted by combining the finite element method (FEM) and discrete element method (DEM) using the ABAQUS® software. By comparing the results of numerical and experimental modal analyses, the accuracy of simulation was verified. To simulate the seismic behavior of the Mikron Bridge, the component of Erzincan earthquake occurred in 1992 was used. The results extracted from the seismic analysis show that some parts of the bridge structure are damaged but not destroyed.

ON STRUCTURAL-SEMANTIC FEATURES OF COMPLEX SENTENCES OF HETEROGENEOUS SUBORDINATION WITH A CAUSAL COMPONENT IN THE SCIENTIFIC STYLE OF THE RUSSIAN LANGUAGE (based on mathematical texts)

All works of scientific style, in particular, in the style of exact sciences, contain a large number of complex sentences. Many of them are multi-component. Of particular interest for the study are the constructions of heterogeneous subordination. They have large “pictorial” means, making it possible to convey the author’s complicated thought in a form that is easy enough for perception. The complex structure breaks down into separate components, allowing the reader to follow the course of logical reasoning, which is of key importance when reading and thinking about sophisticated mathematised texts. However, it would be a mistake to imagine the studied constructions as simply separate predicative parts composed with each other. A complex sentence, built from many components, is a complex “organism” with its own syntactic relations, with a common modality and a predominant connection of structural parts. The subject of this article is constructions consisting of only three components – the main part, the causal subordinate clause and the subordinate clause of the indivisible type. In the style of exact sciences, the causal component makes it possible to clearly establish the cause-and-effect relationship between phenomena, and the entire structure promotes an adequate understanding of complex scientific thought, focusing the reader’s attention on the important points of the presentation of the material. The study was conducted on a number of works by famous modern mathematicians. Their books and textbooks are written in classical mathematical language and are deservedly popular with students and young scientists. In the studied constructions, the causal component can be combined with the component of the indivisible type in different ways. Almost always, the causal component precedes the subordinate clause of the indivisible type and is joined by the conjunctions as and since. When a pronominal-conjunctional correlative subordinate clause acts as a component of the indivisible type, the causal meaning of the entire construction is significantly enhanced. Explanatory and substantive-attributive subordinate clauses lose their independence and are strongly united with the main one in structure and meaning. The construction of the studied constructions turns out to be harmonious: the theme-rheme division of a sentence almost always corresponds to the division of the construction into a subordinate causal clause and a complex main clause. This helps the reader correctly determine the vector of movement of the author’s thought.

Single-machine scheduling with setup time: a case study in the cutting of large-scale structural parts

This article considers a single-machine scheduling problem with setup time to optimize the cutting schedule for structural parts within a railway equipment manufacturing enterprise. When performing parts-cutting operations for various orders, factors such as priority, the material attribute of the steel plate and part specifications need to be considered. Notably, it is beneficial to ensure continuous cutting to minimize steel waste when these parts need the same steel plates. A mixed integer programming model and a two-stage heuristic are proposed to determine the cutting sequence of the parts. The two-stage heuristic involves preprocessing and local search. Finally, the performance of the proposed approaches is assessed using real-world cutting production data. This includes scenarios with more than 10,000 parts, allowing for a thorough evaluation. The results indicate that the proposed two-stage heuristic exhibits significant efficiency and quality advantages compared to the Gurobi tm solver and local search.

Shades of party activism: understanding ZANU-PF youth activists

This article contributes to debates on authoritarian renewal and youth party activism in Africa, based on case study research with youth who are active in the Zimbabwe African National Union-Patriotic Front (ZANU-PF). While youth activism and electoral politics is a subject of rich scholarship, there is limited knowledge on the motivations and agency of the party youth of hegemonic ruling parties. The study engaged a diverse group of ZANU-PF youth to understand their journeys into party activism, how they negotiate the discourses and authoritarian practices promoted by ZANU-PF, and their political agency on behalf of and within the party. The article analyses the everyday ways through which youth activists take part in ZANU-PF structures and activities, noting the dimensions of class and gender. The findings demonstrate the existing ‘shades in activism’, with some youth being born into the party and others joining in search of opportunities, but this does not exclude the possibility of some wanting to promote the prosperity of others. Some self-proclaimed loyalists embrace ZANU-PF narratives, while most are highly critical of the ruling party. We argue that everyday forms of youth activism may constitute authoritarianism from below. Whether ‘at the front’ or ‘at the back’, all ZANU-PF youth contribute to the reproduction of the systems and networks of ZANU-PF, and thus authoritarian renewal, especially because the room for contestation and change from within the ruling party is limited.

A Hybrid Recognition Framework for Highly Interacting Machining Features Based on Primitive Decomposition, Learning and Reconstruction

For the highly interacting machining features, Layered Projection Decomposition Method presents inferior recognition efficiency and accuracy, due to its high-cost 3D projection and failures in determining projection faces for internal occluded faces. To address these issues, we propose a potential hybrid recognition framework. We first introduce a straightforward adjacent projection wire (APW) over UV wires, automatically restoring the full projection wires from highly interacting features. Building on APWs, an efficient hybrid boundary representation and its corresponding unambiguous primitive definitions are proposed by combing with graph-based boundary representations. Subsequently, we design an efficient primitive decomposition method by introducing primitive boundary matching to decide the initial projection faces, and introducing iterative projection boundary expansion to complete the full primitives from occluded faces. Moreover, we establish an efficient Graph Neural Network to learn the distinguishable distributions over the decomposed primitives. Specifically, an Adjacency Attention Unit is proposed to automatically perceive the influence weight of adjacent nodes, leading to more discriminative self-adaptive shape embedding for efficient primitive recognition. Finally, we summarize convenient reconstruction rules to correct the wrong predictions of feature faces with indistinguishable adjacent relationships. To evaluate the effectiveness of the proposed recognition framework, CAD models of complex aircraft structural parts are collected to present a challenging machining feature dataset. Extensive numerical experiments demonstrate that the proposed hybrid recognition framework enables significant improvements over the state-of-the-art machining feature recognition techniques.

Effect of Sandstone Pore Morphology on Mechanics, Acoustic Emission, and Energy Evolution

Roadway section form is an important part of the underground engineering structure, and it directly affects the overall stability of the roadway and the occurrence of underground disasters in coal mines. Based on this, this paper adopts a TYJ-500 electro-hydraulic servo rock shear rheology testing machine to conduct a uniaxial compression test on sandstone containing different prefabricated hole section morphology and analyzes the damage characteristics seen during the damage evolution process, with the help of a high-speed camera and acoustic emission monitoring equipment. The test results show that the pore morphology is the main factor affecting the mechanical parameters of sandstone, and the peak stress and elastic modulus of sandstone with pore sections have the characteristics of increasing and decreasing at the same time, except for the intact rock samples. The pore morphology exhibits central symmetry (circular holes and rectangular holes) damage, more pressure-shear cracks and shear cracks, and the acoustic emission characteristics of high-energy–low-amplitude–low-count of the “two low-trend and one high-trend characteristic curves” attributes; moreover, due to the special existence of its pore morphology, it leads to the rock samples having less energy accumulation and release. The axisymmetric hole types (trapezoidal holes and straight-wall domed holes) are damaged by tensile cracks and shear cracks, and their acoustic emission characteristics show the characteristic properties of “three high-trend characteristic curves” of high-energy–high-amplitude–high-count, and there is a strong elastic energy accumulation and output. The conclusions of this article can provide a certain theoretical basis for the design of coal mine roadway sections in underground structures, failure analysis, and stability evaluation of roadway structures.

Limits of Design and Technique: Lina Bo Bardi Staircases

Staircases, a part of architectural circulation and structure, can become a unique design value with the application technique that directs design and functionality. However, here, attention is drawn to the directive nature of the technique rather than its perception as a deterministic attitude in design. Bo Bardi’s architectonic approach has placed her in a distinguished position among modern architects. The effect of the architect’s staircase design and application technique on building tectonics is worth examining. Thus, this study aims to examine the staircases of Lina Bo Bardi, where design and technique are dissolved in integrity. Bo Bardi’s staircases were examined in terms of meaning, form, function, and technique, with classification for material use. In this context, unique situations were observed in the design and technical applications of reinforced concrete, wood, and metal materials used in stairs. The fact that the place, technique, and the architect’s thought guided the design turned the staircase into a symbolic value and has made the staircase the founding element of the space. This approach, which does not consider design and technique independently, creates a strong reference for today that structural elements such as stairs can be produced as symbols in space.

Deciphering the Cell Surface Sugar-Coating via Biochemical Pathways.

Cell surface components, specifically glycans, play a significant role in several biological functions like cell structure, crosstalk between cells, and eventual target recognition of the cells for therapeutics. The dense layer of glycans, i. e., glycocalyx, could differ in taxon, species, and cell type. Glycans are coupled with lipids and proteins to form glycolipids, glycoproteins, proteoglycans, and glycosylphosphatidylinositol-anchored proteins, making their study challenging. However, understanding glycosylation at the cellular level is vital for fundamental research and advancing glycan-targeted therapy. Among different pathways, metabolic glycan labelling uses the natural metabolic processes of the cell to introduce abiotic functionality into glycan residues. The Bertozzi group pioneered metabolic oligosaccharide engineering using glycan salvage pathways to convert monosaccharides with unnatural modifications. This eventually results in the probe becoming part of the complex cellular glycan structures via click chemistry using copper. On the other hand, the boronic acid-based probe can recognise carbohydrates in a single step without any chemical modification of the surface. This review discusses the significance of glycans as biomarkers for different diseases and the necessity to evaluate them in situ within the physiological environment. The review also discusses the prospect of this field and its potential applications.

Young carers in Ghana: caring activities, ways into care and the impacts of caregiving

ABSTRACT In Ghana, children often provide care and support to family members with disabilities, mental illnesses and other health conditions. Understanding the nature of their caring activities is essential for identifying stressors and promoting better health and wellbeing outcomes for this group of children, described in the wider literature as young carers. This qualitative study investigated the nature and impact of caring activities on young carers aged 11–17 years. The findings revealed that young carers provide domestic, financial, medical and personal care. Caring activities while beneficial, result in a double burden, as young carers often support both the care recipients and their dependents. Despite the challenges associated with caring activities, the study also reveals the myriad reasons young carers enter care work, suggesting that the work of young carers is not simply an obligation or a choice but a process and an integral part of Ghanian family structures. The study highlights the urgent need for formal mechanisms to identify and support young carers and their care recipients in Ghana.

Investigation of the influence of initial residual stress and toolpaths on milling deformation of titanium alloy

Titanium alloy structural components are widely used in the aerospace industry due to their excellent physical properties. However, their susceptibility to machining deformation during milling, attributed to the presence of initial residual stress, poses a significant challenge. Therefore, this paper proposes a finite element model for predicting milling deformation in Ti6Al4V titanium alloy structural parts, considering initial residual stress. The methodology involves establishing the initial residual stress field of titanium alloy components based on a mathematical model of annealing heat transfer and a theoretical study of thermal elasto-plastic constitutive relation, with experimental confirmation of model accuracy. Based on the initial residual stress, a finite element model was developed to predict the maximum deformation under different toolpaths. Finally, a comparative analysis with milling experiments validated the proposed models. The experimental results demonstrated a remarkable alignment with the finite element model, showcasing the correctness of the developed models. The maximum deviation in deformation observed was within the range of 0.003 mm–0.011 mm. This study is the first to comprehensively consider the effects of initial residual stress and toolpaths on titanium alloy milling deformation, and to experimentally verify the proposed model’s accuracy and practicality. It provides a new theoretical basis and technical guidelines for titanium alloy milling deformation.

Residual stress and deformation of welded T-joint between low carbon steel and stainless steel

The welded structures between carbon steel and stainless steel are widely used in many sectors such as pedestrian bridges, food industry, chemical industry, petroleum, and thermal power plants, … These composite structures take advantages of each material for different parts of structure. In the welded structures between carbon steel and stainless steel, the structure is made by T-joint that is the most common. The calculation of residual stress and welding strain of the T-joint between low-carbon and stainless steel materials is the basis to evaluate the working ability of this structure. In this study, the residual stress and welding deformation of the T-joint are determined by the imaginary force method. The double-sided weld of T-joint between low carbon steel and stainless steel is welded simultaneously by MIG welding process. The obtained results of residual stress and welding deformation in this case are compared with the case of single-sided weld so that we can find the difference between residual stress and welding deformation in two cases.

Aza‐Diarylethenes Undergoing Both Photochemically and Thermally Reversible Electrocyclic Reactions

AbstractExploring novel molecular photoswitches plays a crucial role in the field of photo‐functional materials chemistry. In this study, we synthesized aza‐diarylethenes with benzothiophene‐S,S‐dioxide as a part of the hexatriene structure and investigated their photochromic properties. Unlike previously reported aza‐diarylethenes, which exhibit fast thermally reversible photochromism, the compounds synthesized here exhibited pseudo‐photochemically reversible photochromism. Due to their thermal stability, we successfully isolated the colored isomer. X‐ray crystallographic analysis revealed for the first time that the colored isomer adopts a closed‐ring structure with a bond between carbon and nitrogen atoms. Remarkably, these aza‐diarylethenes exhibited not only photochemical ring‐closing and ring‐opening reactions but also thermal ring‐closing and ring‐opening reactions, driven by a thermal equilibrium between the open‐ and closed‐ring isomers. This behavior, unprecedented for common diarylethenes, was elucidated through kinetic analysis, revealing an energy‐level diagram for the thermal equilibrium between these isomers. Furthermore, 1H NMR spectroscopy revealed that both photochemically and thermally generated closed‐ring isomers adopt the same molecular structure, which was well explained based on the reaction mechanism of photochemical and thermal ring‐closing reactions. These findings not only advance the field of aza‐diarylethenes but also inspire future research in the development of new photoswitches.

Research on the Functions and Obstacles of Rural Social Organizations in Rural Governance from the Perspective of Structural Functionalism

Since the reform and opening up, with the transformation of the national governance model, my country's rural social structure has undergone earth-shaking changes. The multi-center governance subject structure has gradually replaced the traditional single governance subject structure and has become the main model for the management of rural social public affairs in my country. As an important subject in governance activities, rural social organizations play a key role in promoting farmers' collective actions and nurturing grassroots democracy. As an important part of the rural social structure, rural social organizations not only have their structure and functions rooted in the transformation of the social structure, but their changes and development also play an important role in the transformation of the social structure. From the perspective of structural functionalism, analyzing the role and function of rural social organizations in the rural social structure has positive theoretical value and practical significance for achieving the effective fit of the structure and function of rural social organizations and building a benign management order in rural society under the background of the rural revitalization strategy.

Creation of a collection fund and study of cultivars of daylilies in the M. M. Gryshko National Botanical Garden of the National Academy of Sciences of Ukraine

Purpose. Analysis and comparative study of daylily cultivars from the collection fund of the M. M. Gryshko National Botanical Garden of the National Academy of Sciences of Ukraine (NBG), selection of assortment for decorative horticulture and landscaping. Methods. Cultivars from the NBG daylily collection were studied. The cultivars were evaluated in terms of their aesthetic and economic attributes, and were classified according to their coloration and the timing of their flowering. The author of the cultivar, country of origin, year of creation and introduction into the NBG were also identified. The cultivars were also grouped according to these parameters. Results. The NBG daylily collection is the result of 40 years of introduction and 20 years of breeding work with this crop at the NBG. It includes 174 world cultivars, 26 cultivars of Ukrainian breeding and more than 1000 hybrid seedlings. Most of the cultivars (79) were introduced in 2000–2009. The main part of the current structure of the daylily collection consists of cultivars bred in the 1960–1970s. Most of these are hybrids from American breeders: David F. Hall (20 cultivars) and Allen Wild (46 cultivars). A total of 15 new cultivars were developed based on the original collection. These new cultivars feature double flowers, a valuable trait for hybrids in Ukraine. For effective use in ornamental horticulture and landscaping, the cultivars were grouped according to flower colour and flowering time. The yellow­flowered group is the most widely represented. A large number of cultivars with red flowers are inherent in hybrids bred between 1980 and 1999. Cultivars from modern breeding are mostly represented by the purple and pink colour group. Most of the cultivars in the collection are early and medium early. The smallest part is made up of medium­late and late hybrids. Conclusions. The modern daylily collection is representative. The cultivars introduced into the NBG illustrate the main stages of breeding work with the crop and the achievements of breeders from different countries of the world. The collection includes early and medium early, medium, medium late and late flowering cultivars. Varying in colour and flowering time, the collection can be effectively used to extend the flowering period of daylilies by three months (from the second decade of May to the second decade of August) in ornamental gardening in Ukraine and in various landscape compositions.

Extreme ionizing properties of a metal-poor, M_UV ~ -12 star complex in the first gigayear

We report the serendipitous discovery of a faint (M$_ UV > -12.2$), low-metallicity (Z $ odot $) ionizing source, dubbed T2c, with a spectroscopic redshift of z$=$6.146. T2c is part of a larger structure amplified by the Hubble Frontier Field galaxy cluster MACSJ0416 and was observed with the James Webb Space Telescope ( NIRSpec integral field unit. Stacking the short-wavelength NIRCam data reveals no stellar continuum detection down to a magnitude limit of UV However, prominent and emissions are detected, with equivalent widths exceeding $200$ and $1300$ respectively. The corresponding intrinsic (magnification-corrected $ 3$) ultraviolet and optical rest-frame magnitudes exceed 34.4 and 33.9 (corresponding to UV $ and M$_ opt $ fainter than -12.2 and -12.8 at $ rest and $ respectively), suggesting a stellar mass lower than a few $10^4$ under an instantaneous burst scenario. The inferred ionizing photon production efficiency ($ ion $) is high: $ ion assuming no dust attenuation and no Lyman continuum leakage. This indicates the presence of massive stars despite the low mass of the object. The very poor sampling of the initial mass function in such a low-mass star-forming complex suggests that the formation of very massive stars might be favored in very low-metallicity environments. T2c is surrounded by Balmer and weak oxygen emission on a spatial scale of a few hundred parsecs, after correcting for lensing effects. This system resembles a region potentially powered by currently undetected, extremely efficient, low-metallicity star complexes or clusters. We propose that massive O-type stars populate these low-mass, low-metallicity, high-redshift satellites, likely observed in an early and short formation phase, and contribute to the ionization of the surrounding medium.

Local Stability Analysis of a Composite Corrugated Steel Plate Pipe-Arch in Soil

The straight part of the corrugated steel plate (CSP) pipe-arch structure in soil may cause local buckling instability due to insufficient load-bearing capacity. Recently, composite CSP pipe-arch has been widely utilized to enhance structural stability, and their stability needs to be thoroughly investigated. This paper studies the local buckling stability problem of the straight part of composite CSP pipe-arch in soil by simplifying the soil support and introducing the inter-layer bonding effect. Based on elastic stability theory, a theoretical mechanical model of composite CSP pipe-arch was proposed. The Rayleigh–Ritz method and the semi-combined composite structure stiffness approximation were used to derive the critical buckling conditions for the straight part of the composite CSP pipe-arch. Through numerical calculation and influencing factors analysis, it is concluded that the critical buckling load of the straight part of the composite CSP pipe-arch structure is affected by the elastic modulus, thickness, Poisson’s ratio, rotational restraint stiffness and side length of the straight part of the material. In particular, it is found that as the inter-layer bonding coefficient increases, the critical buckling load is improved, while the critical buckling wave number is mainly influenced by the width of the straight part, elastic modulus, and inter-layer bonding coefficient. Additionally, we discussed the coupling effect of several key parameters on the stability of the structure. The results of this study offer theoretical foundations and guidance for the application of composite CSP pipe-arch in soil engineering, such as culverts, tunnels, and pipeline transportation.

Academic Coaching in Entry-level Doctor of Physical Therapy Education.

Learners face a variety of academic and personal challenges that may impact performance in Doctor of Physical Therapy (DPT) programs. Academic coaching has emerged as a student support model within undergraduate medical education but has not yet been evaluated in DPT education. The purpose of this method/model presentation was to describe the development, implementation, and evaluation of 2 coaching programs. Two hybrid DPT programs implemented a coaching approach to support students. The coaching framework was centered around an individualized relationship between the learner and faculty coach to promote reflection, growth, agency, and persistence in educational and professional development. Faculty members were prepared and supported to serve as coaches. Coaches met with their assigned students at regular intervals throughout the program, including clinical experiences. The coaching programs were assessed through program exit surveys and an alumni survey. Graduates from both programs reported that the coaching program was effective and supported a sense of belonging or connectedness within their DPT program. They reported several specific activities that were part of the coaching program structure that supported its effectiveness, including group-based orientation activities and 1:1 meetings with their coach. Graduates also provided suggestions for program improvement including increased structure and more opportunities to connect with their peers and coaches in a nonacademic setting. Two DPT programs successfully implemented coaching as their student support model. With appropriate preparation, planning, and support, coaching programs have the potential to provide individualized and meaningful support for DPT students.

Effect of Plow Pan on the Redistribution Dynamics of Water and Nutrient Transport in Soils

Plow pans are an essential part of the agricultural soil structure. By adjusting the soil bulk density and plow pan height, the water and nutrient transport are dynamically redistributed. Plow pans play a crucial role in promoting crop growth, increasing yields, and supporting sustainable land management. In this study, a column experiment was conducted to investigate the effects of plow pan height (10 cm and 15 cm) and bulk density (1.2, 1.4, and 1.6 g cm⁻3) on soil nutrient and water leaching under high-volume (HV) and low-volume (LV) fertilizer applications. The results reveal that the leachate volume decreased by 61.9% at a plow pan height of 10 cm and by 96.2% at a plow pan height of 15 cm when the bulk density was increased from 1.2 to 1.4 g cm⁻3 under HV conditions. There was no leachate when the plow pan bulk density was 1.6 g cm−3. The reserved concentration of alkali-hydrolyzable N in the plow pan soils was the highest when the plow pan had a bulk density of 1.4 g cm−3 and a height of 15 cm. However, when the plow pan height was 15 cm, the available P content in the plow pan soils decreased by 27.0% and 21.0% at bulk densities of 1.4 g cm⁻3 and 1.6 g cm⁻3, respectively, when compared with 1.2 g cm⁻3. Furthermore, the available P concentrations in the plow pan and subsoil layers decreased with an increase in the plow pan height. The available K concentrations in the topsoil decreased by 26.8% and 24.0% when the plow pan bulk density was increased from 1.2 to 1.4 g cm−3 at heights of 10 and 15 cm, respectively. Thus, the optimal plow pan height and bulk density are closely related to the types of soil nutrients. However, it is clear that excessively high bulk densities (e.g., 1.6 g cm−3) negatively impact soil properties. For different nutrient requirements, a bulk density of 1.2 or 1.4 g cm−3 can be chosen, with each providing suitable options based on the specific nutrient needs. This research offers practical insights into changes in nutrient adsorption and fixation in agricultural production associated with alterations in plow pan bulk density.

Impact of typical environments in China's western mountainous areas on the durability of railway concrete: a review

PurposeThis study aims to analyze the impact mechanism of typical environments in China's western mountainous areas on the durability of railway concrete and propose measures to improve durability.Design/methodology/approachWith the continuous promotion of infrastructure construction, the focus of China's railway construction has gradually shifted to the western region. The four typical environments of large temperature differences, strong winds and dryness, high cold and low air pressure unique to the western mountainous areas of China have adverse effects on the durability of typical railway structure concrete (bridges, ballastless tracks and tunnels). This study identified the characteristics of four typical environments in the western mountainous areas of China through on-site research. The impact mechanism of the four typical environments on the durability of concrete in different structural parts of railways has been explored through theoretical analysis and experimental research; Finally, a strategy for improving the durability of railway concrete suitable for the western mountainous areas of China was proposed.FindingsThe daily temperature difference in the western mountainous areas of China is more than twice that of the plain region, which will lead to significant temperature deformation and stress in the multi-layered structure of railway ballastless tracks. It will result in cracking. The wind speed in the western plateau region is about 2.5 to 3 times that of the plain region, and the average annual rainfall is only 1/5 of that in the plain region. The drying effect on the surface of casting concrete will significantly accelerate its cracking process, leading to serious durability problems. The environmental temperature in the western mountainous areas of China is generally low, and there are more freeze-thaw cycles, which will increase the risk of freeze-thaw damage to railway concrete. The environmental air pressure in the western plateau region is only 60% of that in the plain region. The moisture inside the concrete is more likely to diffuse into the surrounding environment under the pressure difference, resulting in greater water loss and shrinkage deformation of the concrete in the plateau region. The above four issues will collectively lead to the rapid deterioration of concrete durability in the western plateau region. The corresponding durability improvement suggestions from theoretical research, new technology development and standard system was proposed in this paper.Originality/valueThe research can provide the mechanism of durability degradation of railway concrete in the western mountainous areas of China and corresponding improvement strategies.

STRUCTURAL AND STOCHASTIC BEHAVIOR OF MEXICAN AGRICULTURAL EXPORTS

Mexican agricultural exports have grown faster than the country’s economy, suggesting a foreign exchange inflow and the use of production factors in Mexico. This work examines both the structural behavior of the agricultural exports and its stochastic behavior using data from 1993 to 2023. The structural part is modeled with three explanatory behaviors: first, the influence in exports of the U.S. economy through its Gross Domestic Product (GDP); second, the effect of the Mexican economy through its own GDP; and third, the search for a more profitable price abroad was modeled with the real exchange rate. On the other hand, the stochastic behavior was modeled with lags of the actual exports and other explanatory variables. After adjusting an autoregressive distributed lag model and verifying the existence of a long-term relationship between Mexican agricultural exports, U.S. GDP, Mexican GDP, and the real exchange rate, it was found that the behavior of the export growth is largely explained by the U.S. economy.