Assembly Of Elements Research Articles

Transition in action: toward a social theory of the governance of transitions.

This article explores how a re-interpretation of the socio-technical, socio-ecological and transition design approaches to transition from the point of view of Niklas Luhmann's general systems theory of society. The need to understand and promote changes that include a technological and ecological dimension has led to different approaches, such as socio-technical or socio-environmental approaches, to incorporate links with society. While these approaches often include sociological insights, they rarely offer a general understanding of how these are embedded into society. We need a new environmental sociology that helps catalyze change processes with a collectively reorganized society, empowering more radically transformative actions to change the current structures and processes that have led us to where we are today. The article offers a cross-sectional look at the socio-ecological and socio-technical systems literature, specifically for what concerns their understanding of the 'systems' in transition and how they can be governed, and re-interpret it from the theoretical lens of the deep sociological knowledge, which refers to the profound understanding of social systems and their dynamics, embedded in Luhmann's theory of social systems. From here, we suggest the second-order coupling for a sociologically grounded understanding of the interactions that comprise socio-ecological and socio-technical systems, heterogeneous and almost self-organizing assemblies of social, technical, and natural elements and processes. At the same time, third-order couplings are analyzed, focused on governance, relationships between operations, and structures mediated by a deliberate attempt to ensure coherence and coordination against the autonomy and heterogeneity of socio-techno-ecological systems. Therefore, this manuscript offers a deeper conceptual and methodological understanding of socio-techno-ecological couplings and systems in the context of sustainability transformation and gives insights into its governance.

Formalization of Elements and Control Schemes in Intelligent System Models

The purpose of the work is to formalize the concepts and principles that form the basis of the mathematical model for controlling the life cycles of intelligent systems. The controlling elements formal description is part of a universal model of such systems. This model part is important for implementing complex intelligent systems with a large amount and diversity of knowledge flows and knowledge processing schemes performed simultaneously. The other two areas of this model are associated with a unified logical-algebraic description of the concept of knowledge representation formalism, as well as concepts related to the architecture of intelligent systems. Formalization of ideas about control in intelligent systems is carried out according to the principle of a hierarchy of controlling elements and processes. The elements of the mathematical model that implements this principle correspond to event-controlled automata with infinite memory and associated algorithms for the automata simulation in specific systems. The objectives of the research include the development of formats for describing the hierarchy of diagrams and assemblies of control elements in a universal model of an intelligent system, and diagrams of algorithms for the functioning of intelligent systems based on the processing of model descriptions. Models of intelligent system control elements hierarchy and execution algorithms for the sets of activated control elements for the implementation time of life cycles of intelligent systems are described by extending the special ontological structures. These structures implement customizations of universal control model

A multiscale steel–concrete interface model for structural applications

In this paper, a new multiscale macro-element formulation for the steel–concrete interface modeling is proposed. This element allows for the representation of the behavior of steel and the interface zone surrounding it. It can also model the interfacial bond stresses in between. Compared to conventional interface models of the literature, which employ separate mesh elements for the steel and the interface, utilizing a macro-element to model both components simplifies the creation of a reinforced concrete structure mesh. Moreover, the macro-element equilibrium is solved using a sub-structuring method that aims to reduce the computational cost. At the global level, it is considered as a four-node element linked to two-dimensional and three-dimensional concrete elements. At the local level, an assembly of multiple three-node bar elements with bond stresses is performed. An inner mesh discretization is therefore possible at the local level independently of the global level. The coupling between the two modeling scales is done using a static condensation technique. The formulation of the macro-element is presented in this paper. A selection of numerical examples is provided. The presented applications demonstrate the robustness of the proposed interface model and its capacity to reproduce the experimental behavior of reinforced concrete structural elements.

A unified dynamic stiffness modeling of multi-plate coupled systems with discrete spring connections

This work presents a unified dynamic stiffness modeling for the vibration analysis of multi-plate coupled systems with discrete spring connections (MPCS-DSC). First, based on the governing differential equation of the plate, the dynamic stiffness matrix (DS) of transverse and in-plane vibration for a completely free rectangular plate is separately derived by combining the generalized superposition method and the projection method. Then, according to the continuity of displacements at the connection point between the spring and the plate, the projected DS matrix of the discrete spring is developed. Then, using an element assembly concept similar to that in the finite element method (FEM), global DS matrices of various coupled systems are determined by assembling the spring's DS matrice and the transverse or in-plane DS matrices of the plate. In order to verify the accuracy and applicability of the proposed method, the free and forced vibration analysis of four types of coupling systems is carried out. The reliability and applicability of the proposed method are confirmed by comparing the present results with those from open literature and the finite element solutions. This study not only expands the application range of DS modeling theory but also provides a powerful tool to investigate the vibration characteristics of the MPCS-DSC.

Experimental Analysis of Bonding in Steel Glued into Pine Timber.

Combining steel with wood has been practised for many years. The issue is related to two main areas, i.e., bonding steel elements with wood so that they serve as connectors facilitating the assembly of wood elements and bonding steel elements to wood beams to improve their load-bearing capacity. In the first case, the adhesives used may be relatively expensive and more difficult to apply, whereas in the second one, especially when steel elements are glued inside the glulam (GL) beams, it is better if the adhesives used are more accessible to apply and cheaper. As it seems rational to reinforce wood with high-modulus ties, research has been carried out to compare the connection quality of commercially available adhesives that can be used for this purpose. Moreover, thermosetting adhesives have been applied as an alternative and cheaper solution. Thermostat adhesives also have a high pH of the bond, which prevents the steel from rusting. The research shows that the load-bearing capacity of the bond depends on whether the bars are ribbed or sheet metal. Moreover, among thermosetting adhesives, the most favourable load-bearing values were obtained using a mixture of PF/pMDI (phenol formaldehyde resin/polymeric diphenylmethane diisocyanate) and powder from recycled tyres. The shear strength of these joints was 1.63 N/mm2 and 3.14 N/mm2 for flat specimens and specimens with ribbed bars, respectively.

A Novel Weak-Form Plane Frame Quadrature Element and its Application to Bridge Analysis

A novel weak-form plane frame quadrature element (WPFQE) is developed. A complex structure can be divided into several non-homogeneous (or homogeneous) elements with large size. The Chebyshev–Lobatto differential quadrature dealing with differentiation and the Gauss–Lobatto quadrature dealing with integration have the same integration points including the ends of each element. Based on the energy variational principle, the diagonal mass matrix and positive definite real symmetric stiffness matrix for the element can be obtained. The unknown quantities at the internal quadrature points of the element can be represented by those at the endpoints of the element based on the principle of static equal effect anterior to the development of global matrices, which significantly reduces the sizes of modified element matrices while maintaining sufficient accuracy, thereby obtaining the small-sized global matrices. Assembly of elements can be performed efficiently just as that in the finite element (FE) method. In the case study, the static and dynamic performances of a three-span high-pier rigid-frame bridge with variable cross-section are studied by applying the proposed method. The results indicate that the orders of structural matrices and calculation time obtained by the WPFQE method are much smaller than those of the FE method.

High-stiffness reconfigurable surfaces based on bistable element assembly and bi-compatible truss attachment

Reconfigurable surfaces contribute to multi-task robotic platforms, such as reconfigurable phased array antennas with variable aperture, by morphing between multiple specified shapes. Controlling each tile to approximate the variating shape of target surfaces requires a large number of accurate actuators. Previous research has demonstrated employing bistable-element-assembly to form reconfigurable surfaces for significant actuation simplification but suffering from low out-of-plane stiffness resulting in the lack of load-bearing capacity for carrying functional units with good mechanical accuracy. This paper proposes a design framework for tile-assembling bistable (TAB) surfaces with bi-compatible truss attachment for two prescribable stable configurations. The bistability comes from joining surface tiles with bistable elements, which contributes to easy actuation with fewer inaccurate actuators. Bi-compatible truss structures, which are only kinematically compatible at the two prescribed states, are introduced to enhance the out-of-plane stiffness of the TAB surface and improve its load-bearing capacity. Additionally and consequently, the kinematic determinacy of the reconfigurable surfaces is increased by the truss introduction, where bistable elements control the metric while truss structures dictate the principal curvature of the surface. This diminishes the redundant degrees of freedom with enhanced shape-approximation and reconfiguration-coordination. Four prototypes are designed and manufactured, which are a three-tile by three-tile (3 × 3) TAB surface that is stable at flat and spherical configurations, a 5 × 5 TAB surface with flat and spherical stable configurations, a 3 × 3 TAB surface that is stable at the flat and saddle configurations, and a 3 × 3 TAB surface that is stable at the sphere and saddle shapes. The out-of-plane stiffness, easiness of actuation, and shape accuracy of all prototypes are evaluated and show promises for real engineering applications.

Unraveling Object-Oriented Dynamics in Architectural Form: The Impact of Randomness in Digital Design Processes

The field of Mereology offers an understanding of the object-oriented dynamics between component parts and theirholistic integrations. Within this framework, architectural form creates a rich landscape of possibilities stemmingfrom the complex interactions among various living and non-living elements. In this perspective, each entity operateswithin its own objective reality, contributing to the rich fabric of relationships that shape architectural form. In thisform-centric approach, deliberate design efforts are complemented by the influences of chance events andrandomness in the assembly of elements. The impact of randomness extends to traditional structural designprocesses, but this effect becomes more pronounced in digital computational environments. As we transition intodigital reality, the representation of objects gains independent significance from their physical counterparts. Here,randomness plays a decisive and constructive role in shaping the digital landscape and forming structures. In thiscontext, this study aims to elucidate the essence and consequences of randomness in the formation of architecturalform. Through meticulous examination of specific examples from form-finding studies, the goal is to determine theextent of randomness's influence.

Ag–thiolate interactions to enable an ultrasensitive and stretchable MXene strain sensor with high temporospatial resolution

High-sensitivity strain sensing elements with a wide strain range, fast response, high stability, and small sensing areas are desirable for constructing strain sensor arrays with high temporospatial resolution. However, current strain sensors rely on crack-based conductive materials having an inherent tradeoff between their sensing area and performance. Here, we present a molecular-level crack modulation strategy in which we use layer-by-layer assembly to introduce strong, dynamic, and reversible coordination bonds in an MXene and silver nanowire-matrixed conductive film. We use this approach to fabricate a crack-based stretchable strain sensor with a very small sensing area (0.25 mm2). It also exhibits an ultrawide working strain range (0.001–37%), high sensitivity (gauge factor ~500 at 0.001% and >150,000 at 35%), fast response time, low hysteresis, and excellent long-term stability. Based on this high-performance sensing element and facile assembly process, a stretchable strain sensor array with a device density of 100 sensors per cm2 is realized. We demonstrate the practical use of the high-density strain sensor array as a multichannel pulse sensing system for monitoring pulses in terms of their spatiotemporal resolution.

Unravelling the mechanisms of antibiotic and heavy metal resistance co-selection in environmental bacteria.

The co-selective pressure of heavy metals is a contributor to the dissemination and persistence of antibiotic resistance genes in environmental reservoirs. The overlapping range of antibiotic and metal contamination and similarities in their resistance mechanisms point to an intertwined evolutionary history. Metal resistance genes are known to be genetically linked to antibiotic resistance genes, with plasmids, transposons, and integrons involved in the assembly and horizontal transfer of the resistance elements. Models of co-selection between metals and antibiotics have been proposed, however, the molecular aspects of these phenomena are in many cases not defined or quantified and the importance of specific metals, environments, bacterial taxa, mobile genetic elements, and other abiotic or biotic conditions are not clear. Co-resistance is often suggested as a dominant mechanism, but interpretations are beset with correlational bias. Proof of principle examples of cross-resistance and co-regulation has been described but more in-depth characterizations are needed, using methodologies that confirm the functional expression of resistance genes and that connect genes with specific bacterial hosts. Here, we comprehensively evaluate the recent evidence for different models of co-selection from pure culture and metagenomic studies in environmental contexts and we highlight outstanding questions.

Hairpin-Empowered Invasive Reaction Combined with Catalytic Hairpin Assembly Cascade Amplification for the Specific Detection of Single-Nucleotide Polymorphisms.

Single-nucleotide polymorphism (SNP) is widely used in the study of disease-related genes and in the genetic study of animal and plant strains. Therefore, SNP detection is crucial for biomedical diagnosis and treatment as well as for molecular design breeding of animals and plants. In this regard, this article describes a novel technique for detecting SNP using flap endonuclease 1 (FEN 1) as a specific recognition element and catalytic hairpin assembly (CHA) cascade reaction as a signal amplification strategy. The mutant target (MT) was hybridized with a biotin-modified upstream probe and hairpin-type downstream probe (DP) to form a specific three-base overlapping structure. Then, FEN 1 was employed for three-base overlapping structure-specific recognition, namely, the precise SNP site identification and the 5' flap of DP dissociation. After dissociation, the hybridized probes were magnetically separated by a streptavidin-biotin complex. Especially, the ability to establish such a hairpin-type DP provided a powerful tool that could be used to hide the cut sequence (CS) and avoid false-positive signals. The cleaved CS initiated the CHA reaction and allowed superior fluorescence signal generation. Owing to the high specificity of FEN 1 for single base recognition, only the MT could be distinguished from the wild-type target and mismatched DNA. Owing to the dual signal amplification, as low as 0.36 fM MT and 1% mutation abundance from the mixtures could be detected, respectively. Furthermore, it could accurately identify SNPs from human cancer cells, as well as soybean leaf genome extracts. This strategy paves the way for the development of more precise and sensitive tools for diagnosing early onset diseases as well as molecular design breeding tools.

Screening Weldable Metal Electrodes for Ag2Se Thermoelectric Devices below 300 °C.

Thermoelectricity has been considered as the most important solution of generating electricity, particularly from low-grade heat below 300 °C. Despite efforts in recent years on exploring alternative materials to only commercialized Bi2Te3, the practical implementation of these new materials has been hindered by inadequate investigation into device design. Given that the utilization of weldable electrodes offers advantages in technical compatibility for a large-scale assembly of thermoelectric elements into modules, a thorough investigation into the potential of weldable metal electrodes at T < 300 °C is imperative. In this work, the diffusion of 11 kinds of thermoelectric materials in common weldable metals (Ni, Fe, Cu, and Ag) was screened. Ag is sorted out as a promising weldable electrode that can directly bond to thermoelectric Ag2Se in this temperature range, leading to a minimization of an interfacial contact resistivity down to 11 μΩ cm2 in a design of the Ag/Ag2Se/Ag structure. The conversion efficiency of ∼3% at ΔT of 95 K with an excellent stability indicates Ag2Se as a top alternative to n-type Bi2Te3 for low-grade heat recovery.

A computational framework for drop time assessment of a control element assembly under fuel assembly deformations with fluid-structure interaction and frictional contact

This paper presents a computational framework for drop time assessment of a control element assembly (CEA) under fuel assembly (FA) deformations. The proposed framework consists of three key components: 1) finite element modeling of CEA, 2) fluid-structure interaction to compute drag force, and 3) modeling of frictional contact between CEA and FA. Specially, to accommodate the large motion of CEA, beam elements based on absolute nodal coordinate formulation (ANCF) are adopted. The continuity equation is utilized to calculate the drag force, considering flow changes in the cross-sectional area during the CEA drop. Lastly, beam-inside-beam frictional contact model is employed to capture practical contact conditions between CEA and FA. The proposed framework is validated through experiments under two scenarios: free falls of CEA within FA, encompassing undeformed and deformed scenarios. The experimental validation of the framework demonstrated that the drop time of CEA can be accurately predicted under the complex coupling effects of fluid and frictional contact. The drop times of the S-shaped deformation case is longer than those of the C-shaped deformation case, affirming the time delay due to frictional force. The validation confirms the potential applicability to access the safety and reliability of nuclear power plants under extreme conditions.

CFD-PBM coupled modeling of the liquid-liquid dispersion characteristics and structure optimization for Kenics static mixer

Kenics static mixers (KSM) are extensively used in industrial mixing–reaction processes by virtue of high mixing efficiency, low power homogenization and easy continuous production. Resolving liquid droplet size and its distribution and thus revealing the dispersion characteristics are of great significance for structural optimization and process intensification in the KSM. In this work, a computational fluid dynamics–population balance model (CFD–PBM) coupled method is employed to systematically investigate the effects of operating conditions and structural parameters of KSM on droplet size and its distribution, to further reveal the liquid–liquid dispersion characteristics. Results indicate that higher Reynolds numbers or higher dispersed phase volume fractions increase energy dissipation, reducing Sauter mean diameter (SMD) of dispersed phase droplets and with a shift in droplet size distribution (DSD) towards smaller size. Smaller aspect ratios, greater blade twist and assembly angles amplify shear rate, leading to smaller droplet size and a narrower DSD in the smaller range. The degree of impact exerted by the aspect ratio is notably greater. Notably, mixing elements with different spin enhance shear and stretching efficiency. Compared to the same spin, SMD becomes 3.7–5.8 times smaller in the smaller size range with a significantly narrower distribution. Taking into account the pressure drop and efficiency in a comprehensive manner, optimized structural parameters for the mixing element encompass an aspect ratio of 1–1.5, a blade twist angle of 180°, an assembly angle of 90°, and interlaced assembly of adjacent elements with different spin. This work provides vital theoretical underpinning and future reference for enhancing KSM performance.

About Some Properties of Structural Steel Used in the Construction of a Railway Bridge Over the Amur River in the Early XX Century

The main stages of construction in 1913–1916 of the railroad bridge across the Amur River near Khabarovsk are presented. The peculiarities of the construction of the structure in the difficult foreign policy conditions of the beginning of the last century, which caused a reduction in the pace of construction, are noted. The most honored organizers, designers and builders of the Amur Bridge are mentioned. Construction materials and places of their extraction, as well as suppliers of structural steel used in the construction of a unique transportation structure are specified. The methods of construction and assembly of the main load-bearing elements of the bridge structure are considered. Special attention is paid to the study of chemical composition, micro- and macrostructure, hardness of structural steels used in the manufacture of bridge spans. Conclusions about the conformity of the chemical composition of the investigated materials to the alloys specified in the current normative documentation, as well as the method of their smelting are formed. Modern metal materials used in the reconstruction of the bridge crossing at the beginning of the XXI century are given for comparison. The functionality of the bridge after reconstruction is reflected and the potential of its further development is given. A promising method of increasing the complex of characteristics of metal products by processing billets in solid-liquid state, which allows to reduce the metal consumption of structures, is considered.

CRISPR/Cas9-based toolkit for rapid marker recycling and combinatorial libraries in Komagataella phaffii

Komagataella phaffii, a nonconventional yeast, is increasingly attractive to researchers owing to its posttranslational modification ability, strict methanol regulatory mechanism, and lack of Crabtree effect. Although CRISPR-based gene editing systems have been established in K. phaffii, there are still some inadequacies compared to the model organism Saccharomyces cerevisiae. In this study, a redesigned gRNA plasmid carrying red and green fluorescent proteins facilitated plasmid construction and marker recycling, respectively, making marker recycling more convenient and reliable. Subsequently, based on the knockdown of Ku70 and DNA ligase IV, we experimented with integrating multiple DNA fragments at a single locus. A 26.5-kb-long DNA fragment divided into 11 expression cassettes for lycopene synthesis could be successfully integrated into a single locus at one time with a success rate of 57%. A 27-kb-long DNA fragment could also be precisely knocked out with a 50% positive rate in K. phaffii by introducing two DSBs simultaneously. Finally, to explore the feasibility of rapidly balancing the expression intensity of multiple genes in a metabolic pathway, a yeast combinatorial library was successfully constructed in K. phaffii using lycopene as an indicator, and an optimal combination of the metabolic pathway was identified by screening, with a yield titer of up to 182.73 mg/L in shake flask fermentation.Key points• Rapid marker recycling based on the visualization of a green fluorescent protein• One-step multifragment integration and large fragment knockout in the genome• A random assembly of multiple DNA elements to create yeast libraries in K. phaffiiGraphical

Numerical investigation of multiphase flow in a channel

Due to the occurrence of failures are divided into design, production and operational. Structural failures occur due to imperfection or violation of the established rules and (or) norms for the design of an object. Production - arise as a result of improper assignment of technological processes for the manufacture or restoration of parts and assembly of a car or are the result of a violation of the accepted technology, unsatisfactory quality of the material of parts or coatings applied to them, the use of insufficiently accurate measuring instruments, failure to meet technical requirements for the manufacture and assembly of elements, as well as the manufacture and assembly of elements and the object as a whole. In the article, basic information about the principles of calculations for solving a system of multiphase Navier–Stokes equations using the control volume method is provided. It is shown that the relationship between velocities and pressure is found using the procedure of SIMPLE. For the numerical solution of this problem, the McCormack scheme was applied. A comparison has been made between each other and with the experimental data. For turbulence, the Spalart–Allmares model was used. And also in the work the movement of sedimentary fluid in different diameters and different Reynolds numbers was studied.

Computational study of a homogenized nonlinear generalization of Timoshenko beam proposed by Turco et al.

&lt;p&gt;Mechanical metamaterials are most often assemblies of stocky beam elements connected through rigid connections, hinges, or flexural joints. The description of these materials through classical beam theories is challenging because of the wide variety of complex phenomena observed in the severe deformation regime mechanical metamaterials must undergo and because most classical beam theories can only be applied to elements with sufficiently high slenderness. In the spirit of Hencky, Turco et al. (2020) has recently formulated an intrinsically discrete nonlinear elastic model suitable for the design of mechanical metamaterials. The objective of this contribution was to present a numerical study of the nonlinear generalization of the Timoshenko beam that results from the asymptotic homogenization of the discrete model introduced by Turco et al. The present numerical study took into account several loading cases and elucidated the sensitivity of the homogenized continuum with respect to axial, bending, and shear stiffness parameters, as well as to load imperfections, in terms of mechanical behavior, including buckling onset and post-critical behavior. It was found that the predictions obtained with the homogenized model in the large deformation regime matched excellently with those of the discrete model proposed by Turco et al.&lt;/p&gt;

Impact of anionic synthetic surfactants of lead ions and their combinations on the pigment profile of freshwater plant organisms Ceratophyllum demersum and Egeria densa

The development of human civilization inevitably leads to the development of production with increasing emissions of many chemicals into the environment. This is especially noticeable in relation to surface waters of fresh water bodies. A very alarming point is that the amount of toxic anthropogenic substances, including heavy metals, is growing every year and is increasingly disturbing the existing ecological balance. Plant organisms of water bodies are among the first to experience the effects of any anthropogenic pollutants and especially heavy metals and surfactants, the amount of which increases in the water of rivers and lakes. Very important in this is the complex of morpho-physiological adaptations associated with restructuring in the structure of chloroplasts. Changes in the content of photosynthetic pigments in plants of two species (Ceratophyllum demersum and Egeria densa) were assessed when they were exposed to very common technogenic substances (lead ions and a solution of anionic synthetic surfactants). In plants, there is a decrease in the activity of molecular transport, inhibition of H+-ATPase, leading to a decrease in the pH of the cytoplasm and activation of hydrolases, which enhance the breakdown of biopolymers. This leads to changes in the expression of individual genes and increased synthesis of a number of stress proteins. Under these conditions, the assembly of cytoskeletal elements is activated, the structures of membrane proteins and lipids change, the level of ATP decreases, free radical processes are activated and the intensity of photosynthesis is inhibited.

Ionization energy losses of cosmic rays in graphene nanostructures calculation

Currently, in the Republic of Kazakhstan, within the framework of the strategic directions of the space industry, fundamental and applied scientific space research is being developed, and practical problems are being solved using space technology. In these studies, special attention is paid to the reliability of on-board equipment under the complex influence of outer space factors. In the development and design of such work as docking and assembly of elements of orbital stations, remote control of automatic interplanetary stations and many others, mathematical and computer modeling is used, which is a highly effective and relatively low-cost method. The purpose of this work is to study the dependence of the energy losses of relativistic ions of cosmic radiation when particles pass through graphene nanostructures in order to predict their radiation resistance when exposed to cosmic radiation particles. The simulation of the trajectories and energy losses of relativistic ions during passing through graphite crystals were performed. Numerical values ​​of the critical channeling angles in a graphite crystal are obtained. It is shown that ion energy losses do not depend on the point of entry of the ion into the crystal and increase sharply with decreasing energy in the energy range less than 1000 MeV/nucleon.