Specific Structural Configuration Research Articles

Formalising variety: the organisation of universities’ regional engagement and third mission activities

ABSTRACT At a time when higher education institutions are increasingly expected to demonstrate societal relevance, it is pertinent to examine why specific structural configurations are chosen to carry out that task. Based on a comparative case study of three merged higher education institutions in Norway, this article examines the three new HEIs’ rationales for and attempts at constructing and maintaining their relations with external stakeholders. The findings illustrate that the type of merger, size and geographical spread of campuses all matter in this regard. Based on our results, a finer-grained set of categories is proposed for mapping the structural configurations of organisations in support of regional engagement and third mission activities. These highlight the importance of identifying positions, arenas, formal agreements and oversight and coordination activities.

Local ratcheting and stress relaxation at notch root of CP-Ti specimen under cyclic loading: Experiment and simulation

Damage and crack always origin from notch, and it is necessary to understand the local ratcheting and stress relaxation at notch root for commercially pure titanium (CP-Ti). Symmetric strain-controlled cyclic test for smooth CP-Ti specimen is conducted to determine the cyclic constitutive relationship based on the combined hardening model. Asymmetric force-controlled cyclic test combined with Digital Image Correlation (DIC) technology is conducted to reveal local ratcheting strain distribution at notch root of CP-Ti specimen, while the distributions of stress, local stress ratio, and local hysteresis curve at notch root are obtained by finite element (FE) simulation. It is found that plastic zone, local ratcheting and stress relaxation at notch root area change significantly with cyclic load levels. In the low stress amplitude region with the mean nominal stress lower than 87 MPa, the small-scale yield occurs, and the notch root is in a state of plastic shakedown. With the mean nominal stress increasing to 96 MPa in the transition region, the notch root is in a state that exceeds the plastic shakedown limit but the continuous ratcheting progress is not found. In the high stress amplitude region with the mean nominal stress higher than 104 MPa, the plastic zone significantly expends, and the notch root is in a continuous ratcheting progress state, accompanied by stress relaxation. For a specific structural configuration, the local ratcheting at notch root is affected by both the load level and the cyclic deformation characteristics of the material. In the high stress amplitude region, the reverse yield occurs at the notch root during unloading, which promotes continuous ratcheting progress and stress redistribution, resulting in stress relaxation. The higher the load level, the larger the ratcheting strain rate, and the lower the stress relaxation rate.

Oblique wave trapping by sinusoidal rippled barrier of finite thickness placed on closely spaced semi-circular seabed

The oblique wave trapping by a sinusoidal rippled barrier (SRB) of finite thickness placed far away from a partially reflecting seawall is examined under the assumption of linear potential flow theory. The sinusoidal ripples are identical, and the barrier is installed in the presence of a semi-circular bottom (SCB). As a special case, the wave trapping by a thick non-rippled barrier (NRB) is also studied to show the significance of the ripples on the wave trapping. The multi-domain boundary element method is employed to tackle the wave-trapping performance of the SRB satisfying Darcy's law. Various types of structural configurations, such as (a) SRB alone, (b) SRB placed on SCB with trapping chamber, (c) without trapping chamber, (d) NRB alone, and (e) NRB placed on SCB with trapping chamber, are proposed and evaluated under oblique wave incidence. The correctness of the study results is verified with the available results for specific structural configurations. The effect of wall reflection, chamber length, plate porosity, and plate submergence depth on wave-trapping coefficients (wave reflection and wave run-up) and force coefficients (horizontal force on the wall and vertical force on the barrier) are presented against relative wavelength. The enhanced wave trapping is obtained after installing a SRB when compared with the NRB of finite thickness. The chamber spacing minimizes the trapping coefficients when compared with the non-chamber rippled barrier. The study recommends the SRB with SCB of thickness 0.10≤D/h≤0.15, porosity 20%, width B/h=2, and chamber spacing 1≤L/h≤2 to replace the gravity-type breakwaters to be installed against intermediate and deep-water waves.

DESIGN AND ANALYSIS OF THE OVERHEAD CRANE WITH SIX VERTICAL COLUMNS

This study delves into the comprehensive examination of an overhead crane’s construction, focusing on its frame, columns, and beams, while considering factors such as strength, stability, and stiffness. Through an in-depth review in the design domain, it is proposed a specific structural configuration for the overhead crane. This design comprises six vertical columns supporting two longitudinal beams equipped with tracks for the trolley’s longitudinal movement. Additionally, cross beams featuring winches are mounted on the trolley’s cross beams. The crane’s columns are securely mounted on a foundation, and struts are employed to attach the crane to the load-bearing wall of the building, ensuring longitudinal and transverse stability. The inclusion of cross truss structures with longitudinal struts further enhances the crane’s overall stiffness, with additional vertical struts provided to augment the left side’s longitudinal stiffness. The study also encompasses the analysis of the crane frame’s construction, complete with the development of an appropriate calculation scheme and the computation of static reactions in supports. Further calculations involve determining the cross-sections of vertical columns and longitudinal beams, ensuring compliance with strength, rigidity, and stability requirements. The selected cross-section for the columns, in the form of a square profile pipe (100×100×3 mm), is meticulously chosen to meet these criteria. Simulation modeling of load scenarios on the crane frame elements in SolidWorks software validates their strength, stiffness, and stability. Mathematical models and calculations provided the optimal parameters and characteristics of each crane component, ensuring a superior level of safety and operational efficiency. These results provide valuable insights for future research in mechanical engineering and the design of industrial mechanisms.

Modeling and Simulation of Dynamics in Soft Robotics: a Review of Numerical Approaches

Abstract Purpose of review In this review, we briefly summarize the numerical methods commonly used for the nonlinear dynamic analysis of soft robotic systems. The underlying mechanical principles as well as the geometrical treatment tailored for soft robots are introduced with particular emphasis on one-dimensional models. Additionally, the review encompasses three-dimensional frameworks, available simulation packages, and various types of interaction models, shedding light on the design, actuation, motion control, and internal and external forces of soft robots. Recent findings Reduced-order models can offer high efficiency in characterizing nonlinear deformations, allowing convenient tailoring based on specific structural and material configurations. For pursuing high simulation accuracy and detailed mechanics, the finite element method proves to be a valuable tool through numerous off-the-shelf platforms. Furthermore, machine learning has emerged as a promising tool to effectively address the challenges within the mechanics community. Summary A wide range of kinematic and dynamic numerical models is available for simulating the behaviors of soft robots, offering exceptional adaptability to different geometries and structures based on existing modeling theories and numerical solution algorithms. However, the trade-off between computational complexity and simulation accuracy remains a challenge in achieving fast, accurate, and robust control of soft robots in complex environments.

Unique Catalytic Mechanism for Ru-Loaded Ternary Intermetallic Electrides for Ammonia Synthesis

Intermetallic electrides have recently shown their priority as catalyst components in ammonia synthesis and CO2 activation. However, their function mechanism has been elusive since its inception, which hinders the further development of such catalysts. In this work, ternary intermetallic electrides La-TM-Si (TM = Co, Fe, and Mn) were synthesized as hosts of ruthenium (Ru) particles for ammonia synthesis catalysis. Although they have the same crystal structure and possess low work functions commonly, the promotion effects on Ru particles rather differ from each other. The catalytic activity follows the sequence of Ru/LaCoSi > Ru/LaFeSi > Ru/LaMnSi. Furthermore, Ru/LaCoSi exhibits much better catalytic durability than the other two. A combination of experiments and first-principles calculations shows that apparent N2 activation energy on each catalyst is much lower than that over conventional Ru-based catalysts, which suggests that N2 dissociation can be conspicuously promoted by the concerted actions of the specific electronic structure and atomic configuration of intermetallic electride-supported catalysts. The NHx formations proceeded on La are energetically favored, which makes it possible to bypass the scaling relations based on only Ru as the active site. The rate-determining step of Ru/La-TM-Si was identified to be NH2 formation. The transition metal (TM) in La-TM-Si electrides has a significant influence on the metal-support interaction of Ru and La-TM-Si. These findings provide a guide for the development of new and effective catalyst hosts for ammonia synthesis and other hydrogenation reactions.

LLAMA: a robust and scalable machine learning pipeline for analysis of large scale 4D microscopy data: analysis of cell ruffles and filopodia

BackgroundWith recent advances in microscopy, recordings of cell behaviour can result in terabyte-size datasets. The lattice light sheet microscope (LLSM) images cells at high speed and high 3D resolution, accumulating data at 100 frames/second over hours, presenting a major challenge for interrogating these datasets. The surfaces of vertebrate cells can rapidly deform to create projections that interact with the microenvironment. Such surface projections include spike-like filopodia and wave-like ruffles on the surface of macrophages as they engage in immune surveillance. LLSM imaging has provided new insights into the complex surface behaviours of immune cells, including revealing new types of ruffles. However, full use of these data requires systematic and quantitative analysis of thousands of projections over hundreds of time steps, and an effective system for analysis of individual structures at this scale requires efficient and robust methods with minimal user intervention.ResultsWe present LLAMA, a platform to enable systematic analysis of terabyte-scale 4D microscopy datasets. We use a machine learning method for semantic segmentation, followed by a robust and configurable object separation and tracking algorithm, generating detailed object level statistics. Our system is designed to run on high-performance computing to achieve high throughput, with outputs suitable for visualisation and statistical analysis. Advanced visualisation is a key element of LLAMA: we provide a specialised tool which supports interactive quality control, optimisation, and output visualisation processes to complement the processing pipeline. LLAMA is demonstrated in an analysis of macrophage surface projections, in which it is used to i) discriminate ruffles induced by lipopolysaccharide (LPS) and macrophage colony stimulating factor (CSF-1) and ii) determine the autonomy of ruffle morphologies.ConclusionsLLAMA provides an effective open source tool for running a cell microscopy analysis pipeline based on semantic segmentation, object analysis and tracking. Detailed numerical and visual outputs enable effective statistical analysis, identifying distinct patterns of increased activity under the two interventions considered in our example analysis. Our system provides the capacity to screen large datasets for specific structural configurations. LLAMA identified distinct features of LPS and CSF-1 induced ruffles and it identified a continuity of behaviour between tent pole ruffling, wave-like ruffling and filopodia deployment.

From meteorology to linguistics: what precipitation constructions in English, French and Spanish tell us about arguments, argumenthood, and the architecture of the grammar

This work takes the variation in syntactic configurations that precipitation verbs display in non-metaphorical contexts in English, French, and Spanish as a case study to examine more general questions about the notions of argument and argumenthood, and how arguments and other elements are introduced in the syntax. It also proposes a unified analysis of such constructions based on a constructivist model (Borer 2005). Specifically, it argues that the syntactic variation attested in this case is a by-product of the combination of general language constraints along with particular features of the functional elements (expletive types), and a general property of the architecture of the grammar: the possibility to merge (and pronounce) the same element in different syntactic positions. The latter explains away: the denominal character of precipitation verbs (Hale & Keyser 1991), thus, the presence of a DP that shares the verb’s root (or a hyponym), and the syntactic and interpretational properties of the DP. In the same vein, some properties and constraints linked to precipitation constructions are reanalyzed as expected outcomes of specific structural configurations, and/or pragmatic effects. The paper also includes a detailed examination of the syntactic evidence that has been put forth to establish the argument status of weather-it, and concludes that once the full interpretation of the syntactic constructions is taken into account, such a claim cannot be justified. Although this work subscribes to the generative tradition, the empirical discussion developed here is relevant beyond this framework.

Does organizational structure render leadership unnecessary? Configurations of formalization and centralization as a substitute and neutralizer of servant leadership

This research draws on the substitutes for leadership theory and the organizational configuration perspective to examine if formalization and centralization moderate the effect of servant leadership on job satisfaction. The findings from a field study and an experimental study suggest that while formalization and centralization did not operate as a substitute or neutralizer independently, however as per the configuration perspective, they interact to moderate the relationship between servant leadership and job satisfaction in different configurations. The results indicate that servant leadership behaviors have more salient effects on followers’ satisfaction when they operate in organizations with lower levels of organizational structure. In addition, under specific structural configurations, formalization can act as a substitute for servant leadership, and centralization can act as a neutralizer on servant leadership. This research contributes to the literatures of servant leadership and the substitutes for leadership theory by enhancing our understanding of the impact of structural configurations.

Escaping the middle-income technology trap: A comparative analysis of industrial policies in China, Brazil and South Africa

Instead of catching up with advanced economies, most middle-income countries have remained stuck in a middle-income trap. We identify and analyse the triple challenges of ‘breaking into’ the global economy, ‘linking up’ into global value chains while ‘linking back’ to the local production system, and ‘keeping pace’ with technological change and innovation. We focus specifically on what we term the ‘middle-income technology trap’: specific structural and institutional configurations that are not conducive to increasing domestic value addition and to sustained industrial and technological upgrading. We explore this through case studies of China, Brazil and South Africa and the analysis of the evolution of their industrial policies and specific institutions, specifically InnoFund model in China, the Embrapa system in Brazil, and the Manufacturing Competitiveness Enhancement Programme in South Africa. Industrial policy implications for middle-income countries in particular, and for developing countries more widely, are finally discussed.

Diseño de una ruta gastronómica de los emprendimientos de comidas típicas en la ciudad de Santo Domingo.

La investigación surge de la necesidad de desarrollar el turismo gastronómico local como fuente alternativa de recursos económicos para el cantón Santo Domingo, el propósito del trabajo es diseñar una ruta gastronómica para el cantón y así potenciar el turismo local. Por lo tanto, para cumplir lo establecido se plantearon objetivos necesarios que determinaron que en el cantón si es factible realizar este proyecto para luego finalizar con su respectivo diseño. El diseño de una ruta dentro del marco investigativo permitió conservar la cultura gastronómica del cantón, por medio de diferentes platos tradicionales que permiten establecer una guía con un origen y configuración estructural especifica que enlaza destinos y así garantiza al turista una experiencia única y placentera.

Determination of Peak Impact Force for Buildings Exposed to Structural Pounding during Earthquakes

Structural pounding between adjacent, insufficiently separated buildings, or bridge segments, has been repeatedly observed during seismic excitations. Such earthquake-induced collisions may cause severe structural damage or even lead to the collapse of colliding structures. The aim of the present paper was to show the results of the study focused on determination of peak impact forces during collisions between buildings exposed to different seismic excitations. A set of different ground motion records, with various peak ground acceleration (PGA) values and frequency contents, were considered. First, pounding-involved numerical analysis was conducted for the basic parameters of colliding buildings. Then, the parametric study was carried out for different structural natural periods, structural damping ratios, gap sizes between buildings and coefficients of restitution. The results of the analysis conducted for the basic structural parameters indicate that the largest response of the analysed buildings was observed for the Duzce earthquake. The parametric study showed that the pounding-involved structural response depended substantially on all parameters considered in the analysis, and the largest response was observed for different ground motions. The results of the study presented in this paper indicate that the value of the peak impact force expected during the time of the earthquake does not depend on the PGA value of ground motion, but rather on the frequency contents of excitation and pounding scenario. It is therefore recommended that the peak impact force for buildings exposed to structural pounding during earthquakes should be determined individually for the specific structural configuration taking into account the design ground motion.

Wave transformation due to barrier-rock porous structure placed on step-bottom

ABSTRACT The oblique wave transport through barrier-rock porous structure for different structural configurations are examined considering impermeable uniform/step-bottom topography. The numerical study is performed on using the linearised wave theory and mode-coupling relation at seaward/leeward structural interfaces. The wave reflection, transmission, energy absorption, wave force on the rigid wall, the wave force on seaward and leeward barriers is reported considering various ranges of porosity, friction factor, structural thickness, trapping chamber spacing and angle of impinging. The analytical relations for calculating the wave reflection and transmission coefficients are reported for plane-wave approximation and the effectiveness of present analytical results are verified with the available literatures for specific structural configurations. The fluid resonance plays a vital role in the design of trapping chamber thickness, and resonating troughs in wave scattering suggest an effective structural configuration for better wave damping.

Modeling, analysis and seismic design of structures using energy dissipators SLB

This paper initially describes aspects of the modeling of structures equipped with energy dissipators Shear Link Bozzo (SLB) and develops two iterative design procedures to select these devices. This methodology is applied to a precast 5-story reinforced concrete building. The SLB energy dissipation devices are initially stiff, but ductile with a range of yielding forces from 36 kN to 900 kN characterized by 52 + 52 standard devices. Moreover, these devices can be combined in parallel giving a very wide range of possibilities for selection and corresponding structural response. Therefore, to simplify its automatic selection, this article presents two procedures: (1) direct iteration and (2) inverse or fixed force iteration. Both procedures were implemented in an automatic application or “plugin” for the ETABS program that automates its selection for a specific structural system or architectural configuration of these elements. Using these devices, the energy introduced by an earthquake into the structure can be dissipated, protecting other structural elements that suffer damage. The SLB energy dissipation devices are affordable to get a significant performance improvement in the overall structural response. This work presents a five-story precast reinforced concrete building frame, called SLB Building, that provides 4 departments per level all with a diaphanous interior floor. The building is made up of 11 columns with a constant 40x40cm section and all its beams have hinges at the ends. This building was equipped with 120 small SLB devices showing its performance for the maximum earthquake of Peruvian seismic code without ductility reduction (R = 1) by means of nonlinear time history with ten seismic records compatible with the S1 soil spectrum. In this structure, all seismic energy dissipation was concentrated in these devices so there would be no structural damage. In addition, the levels of non-structural damage were controlled with initial stiffness of these devices since lateral displacements were reduced to levels below the Peruvian seismic code (or even immediate occupancy for devices greater than those provided in this example). At the same time, the levels of acceleration decrease in height to only 0.3g and the base shear coefficient is reduced from almost 1.2 to only 0.12-0.2 (this means an R factor between 6 and 10 without structural damage).

Support effect on the reactivity and stability of Au25(SR)18 and Au144(SR)60 nanoclusters in liquid phase cyclohexane oxidation

Abstract Using oxide supported atomically precise gold nanoclusters is an emerging field in heterogeneous catalysis. Such well-defined nanocatalysts represent a rather new model system enabling fundamental insights in catalytic reactions. In the present work, the stability of Au25 and Au144 clusters, supported either on TiO2 or SiO2, was examined upon thermal air pretreatment and, for the first time, upon liquid phase oxidation reaction. A pronounced influence of the support (TiO2 vs. SiO2) and cluster size (Au25 vs. Au144) was revealed by XAS, DRS and STEM. Upon pretreatment, Au144 was more stable which may be related to its specific cluster core structure and staple configuration. The catalytic properties in liquid phase cyclohexane oxidation were clearly size dependent, with Au144 yielding higher TOF values, particularly in the case of SiO2 supported catalysts. However, with respect to selectivity, TiO2 supported catalysts led to higher KA production than SiO2 supported ones. This can be explained by the different reaction pathways, as observed by in situ ATR. HERFD-XAS measurements of Au144/TiO2 catalysts revealed a pronounced cluster structure modification towards bulk gold during the reaction, in contrast to a high stability of Au144/SiO2. This study demonstrates the important role the support material has on the reactivity and stability of gold nanoclusters, which is key for their catalytic function.

The rise of person agreement in East Lezgic: Assessing the role of frequency

Abstract Grammaticalization is often considered to reflect frequent co-occurrence of certain elements in certain positions. This paper tests the frequency-based account of the grammaticalization of person agreement, comparing the grammaticalization of person agreement in Tabasaran, a Lezgic language, with the syntax of free pronouns in closely related Agul. Our assumption is that the situation in Agul, where person marking is not grammaticalized, approximately reflects a diachronic stage prior to the grammaticalization of person marking in closely related Tabasaran. We find little evidence in support of a frequency-based approach, at least when frequency is treated in terms of global frequencies. We do, however, identify a highly frequent verb that already in Agul appears to regularly associate with the pattern that has generalized to become person agreement in Tabasaran. We suggest specific information structural configurations associated with this verb, which have provided the impetus for the development. More generally, we show that while global measures of frequency may not yield the correct predictions, investigating the syntactic constructions associated with individual lexical items may be more revealing, and provide a more realistic model for reconstructing the paths of syntactic change involving the generalization of existing and quite local patterns.

On the Generality of Molecular Volcano Plots

AbstractIn homogeneous catalysis, the structure and electronic configuration of the active catalysts can vary significantly. Changes in ligation, oxidation, and spin states have the potential to influence the catalytic cycle energetics strongly that, to a large degree, dictate the catalytic performance. With the increased use of computational screening strategies aimed towards the identification of new catalysts, ambiguity surrounding structure/electronic configurations can be problematic, as it is unclear which species should be computed to determine a catalyst's properties. Here, we show that a single volcano plot constructed from linear free energy scaling relationships is able to account for variations in ligation, oxidation, and spin state. These linear scaling relationships can also be used to predict the free energies associated with a specific structure and electronic configuration of a catalyst based on a single descriptor. As a result, a single volcano plot can be used to screen prospective new catalysts rapidly.

Uniformity of thermal fields in multi-heat-sources synthesis and the elongations of graphene sheets composites and polymers applied in the Bionic robots

A three-dimensional heat transfer numerical model is proposed here for the soft-body caterpillar-like robots to present insights for biologists and engineers understanding heat-induced locomotion of these robots. Thermal field distribution of the soft robot body made by the polymer composites is firstly modeled by the use of computational fluid dynamic methodology. The computed spatial distributions of thermal fields were subsequently compared with experimental ones. The achieved agreement between numerical and experimental results further validated the numerical methodology well. Uniformity of thermal field, uniformity factors and typical temperatures for the soft robot body are numerically calculated in details. The results demonstrated that power density P, body size W and thermal conductivity (graphite content) κr have significant effects in the spatial distributions of heat transfer. Furthermore, the specific volume ratio and optimal structural configuration of the heating sources (GS composites: graphene sheets and pliable polydimethylsiloxane) and substrates (pure PDMS: polydimethylsiloxane) are determined upon that the maximum elongation is achieved at different operation conditions of P, W and κr respectively. Present research could contribute to the remotely powered and controlled soft robots made by polymer composites.

Combining Precipitation and Vitrification to Control the Number of Surface Patches on Polymer Nanocolloids.

In an effort to incorporate increasingly higher levels of functionality into soft nanoparticles, heterogeneously structured particles stand out as a simple means to enhance functionality by tailoring only particle architecture. Various means exist for the fabrication of particles with specific structural configurations; however, the tunability of particle morphology is still a challenging and often laborious task, especially in self-assembled systems where a single equilibrium configuration dominates. Improved strategies for multipatch particle assembly are therefore needed to allow for the tailoring of particle structure via a single, continuous assembly route. One means of accomplishing this is through kinetic trapping of particle morphologies along the path to the final equilibrium configuration in precipitation-induced, phase-separating polymer blends. Here, we demonstrate this capability by using rapid nanoprecipitation to control the overall size, composition, and patch distribution of soft colloids. In particular, we illustrate that polymer feed concentration, blend ratio, and polymer molecular weight can all serve as functional handles with which to consistently alter particle patch distributions in a self-assembling homopolymer system without redesigning the starting materials. We furthermore delineate the role of polymer vitrification in the determination of particle structure.

Tectonic and stratigraphic evolution of the Punta del Este and Pelotas basins (offshore Uruguay)

Regional seismic reflection profiles and well data from the Uruguayan margin were integrated in order to analyse and illustrate its tectonic and stratigraphic evolution. The evolution of the Punta del Este and Pelotas basins is divided into four major phases: pre-rift (Palaeozoic); rift (Jurassic–Early Cretaceous); transition (Barremian–Aptian) and post-rift (Aptian–Present). Each of these phases is characterized by a specific structural configuration and a stratigraphic architecture related to basin type, tectonic elements, sediment supply and base-level changes. During the geological evolution of the Uruguayan continental margin, a NE migration of depocentres occurred. The Cretaceous depocentre is located in the Punta del Este Basin, while the Cenozoic depocentre is located in the Pelotas Basin.