Column Position Research Articles

Investigating the impact of asymmetric macular sensitivity on visual acuity chart reading in choroideremia.

Degeneration in choroideremia, unlike typical centripetal photoreceptor degenerations, is centred temporal to the fovea. Once the fovea is affected, the nasal visual field (temporal retina) is relatively spared, and the preferred retinal locus shifts temporally. Therefore, when reading left to right, only the right eye reads into a scotoma. We investigate how this unique property affects the ability to read an eye chart. Standard- and low-luminance visual acuity (VA) for right and left eyes were measured with the Early Treatment of Diabetic Retinopathy Study (ETDRS) chart. Letters in each line were labelled by column position. The numbers of letter errors for each position across the whole chart were summed to produce total column error scores for each participant. Macular sensitivity was assessed using microperimetry. Central sensitivity asymmetry was determined by the temporal-versus-nasal central macular difference and subsequently correlated to a weighted ETDRS column error score. Healthy volunteers and participants with X-linked retinitis pigmentosa GTPase regulator associated retinitis pigmentosa (RPGR-RP) were used as controls. Thirty-nine choroideremia participants (median age 44.9 years [IQR 35.7-53.5]), 23 RPGR-RP participants (median age 30.8 years [IQR 26.5-40.5]) and 35 healthy controls (median age 23.8 years [IQR 20.3-29.0]) were examined. In choroideremia, standard VA in the right eye showed significantly greater ETDRS column errors on the temporal side compared with the nasal side (p = 0.002). This significantly correlated with greater asymmetry in temporal-versus-nasal central macular sensitivity (p = 0.04). No significant patterns in ETDRS column errors or central macular sensitivity were seen in the choroideremia left eyes, nor in RPGR-RP and control eyes. Difficulty in tracking across lines during ETDRS VA testing may cause excess errors independent of true VA. VA assessment with single-letter optotype systems may be more suitable, particularly for patients with choroideremia, and potentially other retinal diseases with asymmetric central macular sensitivity or large central scotomas including geographic atrophy.

Study on Vibration Reduction Effect of the Building Structure Equipped with Intermediate Column–Lever Viscous Damper

Generally speaking, the traditional lever amplification damping system is installed between adjacent columns in a building, which occupies a significant amount of space in the building. In contrast to amplification devices in different forms, the damper displacement of the intermediate column damper system is smaller, and the vibration reduction efficiency is lower. In light of these drawbacks, this study proposes a new amplification device for energy dissipation and vibration reduction, which is based on an intermediate column–lever mechanism with a viscous damper (CLVD). Initially, a specific simplified mechanical model of CLVD is derived. Subsequently, an equivalent Kelvin mechanical model of CLVD is derived to intuitively reflect CLVD’s damping and stiffness effect. The damping ratio added by CLVDs to the structure is calculated according to that model; the additional damping ratio and additional stiffness are utilized to calculate the displacement ratio Rd and shear force ratio Rv of the structure with CLVDs to the structure without CLVDs. Rd and Rv are introduced to evaluate the vibration reduction effect of the structure with CLVDs, and the effects of various parameters (such as intermediate column position, beam’s bending line stiffness, lever amplification factor, damping coefficient, and earthquake intensity) on Rd and Rv are analyzed. The results indicate that when the ratio of the distance from the intermediate column to the edge column to the span of the beam is 0.5, CLVD owns the optimal vibration reduction effect. Increasing the beam’s bending line stiffness is beneficial for CLVD to control structural displacement and shear force; when the leverage amplification factor is too large, the CLVD provides the structure with stiffness as the main factor, followed by damping. Additionally, when the ratio of the displacement amplification factor to the geometric amplification factor satisfies fd/γ = 1/21−0.5α, the CLVD has the optimal displacement control effect on the structure. After that, measures are provided to optimize the CLVD in different situations in order to effectively control the inter-story displacement and the story shear force of the structure. Consequently, a nine-story frame is taken as an example to elaborate the application of CLVDs in the design for energy dissipation and vibration reduction. The results reveal that the CLVD scheme adopting the proposed optimization method can effectively enhance the displacement amplification ability of CLVDs, resulting in an additional damping ratio of up to 12%. At the same time, the inter-story displacement was reduced by almost 40% under fortification earthquakes. Through the research in this study, designers can obtain a new choice in structural vibration reduction design.

Shaking table test and numerical analyses of a multi‐story traditional tower‐style building

AbstractThe traditional tower‐style building (TTSB) is an innovative structural form constructed in modern cities imitating the overall appearance of ancient timber pagodas, and it is an extraordinarily cultured high‐rise construction. The limited stipulations for high‐rise TTSBs in the seismic design code pose challenges in assessing the reliable performance of the unique structure subjected to severe earthquakes. This paper presents the shaking table test and numerical analyses of a 1/15‐scale 13‐story TTSB specimen with an integral tower height of 5.36 m, which is a steel frame‐braced core‐tube structure consisting of seven bright floors (built‐out stories evident from the outside, BF) and six dim floors (built‐in stories not apparent from the outside, DF), with transition columns and stiffening trusses around the exterior perimeter. The experimental results showed that the tested tower‐style building had excellent seismic performance and reliable structural integrity. It only experienced minor damage when subjected to extremely high‐intensity motions. The interstory drift, dynamic strain, and floor acceleration response of the core‐tube region with eccentric steel braces were more significant under severe excitation than those with cross‐centered symmetric steel braces. The vertical reaction increased at the upper floor of the tower under vertical acceleration, and differences in the dynamic response of the middle and upper floors were much more apparent after the test. Moreover, 3D numerical simulation models of the tested tower were established and validated against the test responses. Successively, the validated numerical model was used to investigate the influence of the transition column at different floors on the peak interstory drift response and the relevant strain distribution, and the proposal for a proper position of the transition column was recommended at the end.

Bayesian inference of atomic column positions in scanning transmission electron microscopy images

Abstract Atomic-resolution scanning transmission electron microscopy combined with 2D Gaussian fitting enables the accurate and precise identification of atomic column positions within a few picometers. The measurement performance significantly depends on the signal-to-noise ratio of the atomic columns. In areas with low signal-to-noise ratios, such as near surfaces, the measurement performance was lower than that of the bulk. However, previous studies evaluated the accuracy and precision only in bulk areas, underscoring the need for a method that quantitatively evaluates the accuracy and precision of each atomic column position with various signal-to-noise ratios. This study introduced Bayesian inference to assess the accuracy and precision of determining individual atomic column positions under various signals. We applied this method to simulated and experimental images and demonstrated its effectiveness in identifying statistically significant displacements, particularly near surfaces with signal degradation. The use of vector maps and kernel density estimate plots obtained from Bayesian inference provided a probabilistic understanding of the atom displacement. Therefore, this study highlighted the potential benefits of Bayesian inference in high-resolution imaging to reveal material properties.

Experimental Study on the Seismic Performance of Brick Walls Strengthened by Small-Spaced Reinforced-Concrete–Masonry Composite Columns

Through low-cycle reciprocating tests on 11 masonry wall specimens strengthened using reinforced-concrete–masonry composite columns, the effects of the position of the composite column, height-to-width ratio, column reinforcement ratio, and axial load ratio on their load-carrying capacity, stiffness, ductility, and energy dissipation capacity were investigated. It was experimentally found that, by strengthening brick walls with RC–masonry composite columns, the concrete and masonry parts can work together effectively, the failure mode shifts from shear to flexural failure, and the strengthened walls exhibit improved bearing capacity, ductility, and energy dissipation performance compared to unstrengthened masonry walls. It is suggested the composite columns can be placed at the ends of the wall if a strengthening measure is required. For walls with height-to-width ratios greater than 1, placing composite columns in the middle of a wall has little effect on the bearing capacity and stiffness of the wall but can improve the ductility of the wall. The height-to-width ratio is a primary factor influencing the structural performance of masonry walls strengthened using composite columns. A smaller height-to-width ratio leads to higher load-carrying capacity and stiffness but may result in reduced ductility. In comparison, the impact of the column reinforcement ratio and axial load ratio is relatively weaker. The flexural capacity of the masonry wall after strengthening can be obtained using the calculation method for concrete members subjected to a combined action of flexure and compression, in which the compressive strength of the masonry is considered.

Optimising Rehabilitation Strategies for Postpartum Elderly Gravida with In Vitro Fertilisation Conception

Optimising Rehabilitation Strategies for Postpartum Elderly Gravida with In Vitro Fertilisation Conception

Progressive collapse resistance of self-centering infilled precast concrete frame under side column removal scenario

In this study, the collapse experiment of a 1/2 scaled two-story and two-span self-centering precast concrete (PC) infilled frame specimen was carried out by quasi-static pushdown side column regime. The test results indicated that under side column removal scenario, the structural damage only occurred in the span adjacent to the failure column. The incline cracks in the infill wall showed a trend of developing from both sides to the middle portion during the test. Affected by the position of failure column, the initial stiffness and peak resistance of specimen under side column removal scenario were only 0.25 times and 0.44 times that of specimen under middle column removal. Further numerical simulation results indicated that the layout positions of infill wall, the initial prestress between beams and columns as well as the strength of bed joints had a greater effect on the vertical resistance of self-centering PC frames when side column failed. Moreover, the lateral restraints of the side columns on both sides could promote the development of compressive arch action (CAA) and catenary action (CA), and fully mobilized the tensile force of steel strands to undertake vertical load in the large deformation stage of the structure. Finally, a simplified analytical method was proposed to accurately predict the vertical resistance of self-centering PC frames in the CAA stage under side column removal scenario.

A three-dimensional numerical simulation method for seismic nonlinear response of underground structure in liquefiable site and analysis of structural damage

Considering the effect of dynamic interaction between liquefiable soil and underground structure, simulating the nonlinear seismic response of underground structures through simple, convenient, and reliable 3D numerical model is still a great challenge at present. A three-dimensional numerical simulation method for dynamic response of underground structure in liquefiable site is proposed based on the centrifuge shaking table test designed for a subway station buried in liquefiable interlayer site carried out in the previous period. The numerical model takes into account the characteristics of sand prone to large deformation after liquefaction and the nonlinear characteristics of the contact between saturated soil and structure. The typical numerical calculation results are compared with the experimental results to verify the correctness of the numerical model, and the extended analysis of the structural damage is carried out, which visually shows the damage distribution of structure under different functional states after earthquake. The analysis of structural damage shows that the junction position of middle column and longitudinal beam is more prone to tensile damage under the horizontal earthquake action; while after considering the horizontal-vertical seismic effect, the middle column will produce additional compressive damage due to the vertical inertia force, and the end of middle column should be paid attention to in seismic design.

Regionalization of the vertebral column and its correlation with heart position in snakes: Implications for evolutionary pathways and morphological diversification.

Spinal regionalization has important implications for the evolution of vertebrate body plans. We determined the variation in the number and morphology of vertebrae across the vertebral column (i.e., vertebral formula) for 63 snake species representing 13 families using intracolumnar variation in vertebral shape. Vertebral counts were used to determine the position of the heart, pylorus, and left kidney for each species. Across all species we observed a conspicuous midthoracic transition in vertebral shape, indicating four developmental domains of the precloacal vertebral column (cervical, anterior thoracic, posterior thoracic, and lumbar). Using phylogenetic analyses, the boundary between the anterior and posterior thoracic vertebrae was correlated with heart position. No associations were found between shifts in morphology of the vertebral column and either the pylorus or left kidney. We observed that among taxa, the number of preapex and postapex vertebrae could change independently from one another and from changes in the total number of precloacal vertebrae. Ancestral state reconstruction of the preapex and postapex vertebrae illustrated several evolutionary pathways by which diversity in the vertebral column and heart position have been attained. In addition, no conspicuous pattern was observed among the heart, pylorus, or kidney indicating that their relative positions to each other evolve independently. We conclude that snakes exhibit four morphologically distinct regions of the vertebral column. We discuss the implications of the forebody and hindbody vertebral formula on the morphological diversification of snakes.

AUTOMATION OF CALCULATING THE POSITION OF THE BOUNDARY COLUMN BETWEEN ADJACENT TRACKS OF DIFFERENT DESIGNS

The purpose of the study is to develop appropriate algorithms and procedures used in simulating the movement of a model car along adjacent tracks. These algorithms will automate the process of calculating the position of the boundary column between adjacent tracks of different designs with a given accuracy and compliance with traffic safety requirements. Scientific methods. In the course of the study, simulation methods were used to model the movement of the design car along the adjacent tracks. Analytical geometry methods were used to determine the main geometric characteristics of the car in terms of its relative position relative to the track axis. Results. The following conclusions were obtained as a result of the research. The multivariability of the design of adjacent tracks in the plan does not make it possible to create a universal analytical expression for determining the position of the boundary column. Existing methods for calculating the position of the boundary post provide for the maximum spread of the dimension in curved sections, which results in an excessive distance between the boundary post and the switch and inefficient use of the useful track length. The developed algorithms and procedures for determining the position of the boundary column are universal and allow automating the process of calculating the position of the boundary column between adjacent tracks of different designs in the plan, even when technical standards or parameters of the design cars change. In this case, only the initial data for the calculation need to be changed. Scientific novelty. The scientific novelty lies in the development of algorithms and procedures for formalizing the design of adjacent tracks and simulating the movement of design rolling stock on them. Practical significance. The developed algorithms and procedures can be implemented in the form of a software package for automated calculation of the position of the boundary column with high accuracy. Also, the obtained results of calculations can be used in the analysis and creation of an analytical description of the position of the boundary column for complex structures of adjacent tracks.

Impact of selected risk factors on motor performance in the third month of life and motor development in the ninth month.

Proper motor development can be influenced by a range of risk factors. The resulting motor performance can be assessed through quantitative and qualitative analysis of posture and movement patterns. This study was designed as the cohort follow-up of the motor assessment and aimed to demonstrate, in a mathematical way, the impact of particular risk factors on elements of motor performance in the 3rd month and the final motor performance in the 9th month of life. Four hundred nineteen children were assessed (236 male and 183 female), including 129 born preterm. Each child aged 3 month underwent a physiotherapeutic assessment of the quantitative and qualitative development, in the prone and supine positions. The neurologist examined each child aged 9 month, referring to the Denver Development Screening Test II and assessing reflexes, muscle tone and symmetry. The following risk factors were analyzed after the neurological consultation: condition at birth (5th min Apgar score), week of gestation at birth, intraventricular hemorrhage, respiratory distress syndrome, and the incidence of intrauterine hypotrophy and hyperbilirubinemia determined based on medical records. A combination of several risk factors affected motor development stronger than any one of them solely, with Apgar score, hyperbilirubinemia, and intraventricular hemorrhage exhibiting the most significant impact. Premature birth on its own did not cause a substantial delay in motor development. Nonetheless, its co-occurrence with other risk factors, namely intraventricular hemorrhage, respiratory distress syndrome, and hyperbilirubinemia, notably worsened motor development prognosis. Moreover, improper position of the vertebral column, scapulae, shoulders, and pelvis in the third month of life may predict disturbances in further motor development.

Influence of column position on stability of stiffened deep mixed column-supported embankment over soft clay

Influence of column position on stability of stiffened deep mixed column-supported embankment over soft clay

Components influencing parasitism by Dadaytrema oxycephala (Digenea: Cladorchiidae) in Neotropical fish

The components that mold the structure of parasitic fauna are used as objects of study in an attempt to find patterns in their distribution. It is known that phylogeny (represented by specificity), host ecological traits (for example, feeding habits, position of the water column, reproductive strategies, body size, and age), and the environment affect the distribution and occurrence of parasites. In tropical regions, digeneans show high diversity, and the species Dadaytrema oxycephala is known to parasitize a wide range of host species. In this context, the objective of the present study is to analyze the components that affect the occurrence of D. oxycephala in Neotropical fish. We used data from the literature that contained the abundance of this parasite, as well as the geographic location and host species, and evaluated the influence of ecological traits, specificity, and latitude on parasite abundance, using a generalized linear mixed model (GLMM). The abundance of D. oxycephala can be explained by trophic level and position in the water column and latitude. However, coevolutionary processes are also extremely important, and the distribution of this parasite was not equal, showing high abundance for the genus Piaractus, which are the preferred hosts, even if the parasite is considered generalist. In short, host ecological traits are the important components in the distribution and occurrence of D. oxycephala, as well as the latitude.

Analysis of Riser Gas Pressure from Full-Scale Gas-in-Riser Experiments with Instrumentation

Summary Because the use of adaptive drilling processes, such as managed pressure drilling (MPD), facilitate drilling of otherwise nondrillable wells with faster corrective action, the drilling industry should include the effect of gas dispersion, bubble suspension, fluid compressibility, and riser ballooning to avoid the overestimation of riser pressure and to produce more efficient well control methods. The IADC Deepwater Well Control Guideline recommends always addressing riser gas first, before proceeding to control the well in a well control situation. The intent is to remove the risk of gas reaching the surface and the rig floor, putting personnel and assets at risk. However, with the availability of equipment on the rig dedicated to handling riser gas and the fact that the riser is isolated from the wellbore, the atmosphere reduces the level of risk of gas in the riser, whereas the well below the subsea blowout preventer (SSBOP) poses a greater risk. In this paper, we discuss the results from full-scale experiments recently conducted in an extensively instrumented test well (LSU Well-2) and demonstrate that the riser pressures resulting from upward transport or aggregation of riser gas are much lower than the values estimated using the single-bubble model and industry thumb rules. We explain the danger of using an open-top riser top during the monitoring of gas-in-riser and how the situation can get out of control due to the potential dynamic unloading situation. Our research also demonstrates the minimal fluid bleedoff volumes required to reduce pressure buildup consequences of free gas migration in a fully closed riser containing low-compressibility liquid. A differential pressure methodology used in this paper for analysis was also used for detecting the presence, position, void fraction, and lead and tail velocity of the gas column in real time during each of the tests to make decisions during the tests. The results from a successful application of the fixed choke constant outflow (FCCO) method as a new method for circulating out gas from the riser by staying within the gas-handling capacity of the existing mud gas separator (MGS) on the rig are presented. This is the industry’s first test of the FCCO method.

Behavior and design of steel-tubed-reinforced-concrete columns reinforced with non-through section steel

This paper presents an experimental and analytical study on the seismic behavior and load-carrying capacity of the steel-tubed-reinforced-concrete (STRC) column reinforced with non-through section steel. A total of 8 columns with different built-in section steel lengths and varying axial compression ratios were tested under low-period cyclic load. The damage features, hysteresis curves, and steel tube strain of the specimens were analyzed, respectively. The effects of built-in length of section steel and axial compression ratio on seismic performance were discussed. The results indicated that: the STRC columns are mainly subjected to compression-bending failure mode. Within a critical built-in length range of section steel, the section steel-concrete transition section is damaged, and the seismic performance and bearing capacity increase significantly with the increase in section steel length. When the critical value is exceeded, the column root section is damaged, and the performance of the specimens is no longer improved. The damage position and lateral load capacity of the STRC column with non-through section steel are determined by the critical length and the bearing capacity of the two typical sections. Based on experimental and finite element analysis, the calculation methods for the compression and bending capacity of two typical sections are given, and the calculation formula for the critical length of section steel is provided.

Direct observation of cation diffusion driven surface reconstruction at van der Waals gaps

Weak interlayer van der Waals (vdW) bonding has significant impact on the surface/interface structure, electronic properties, and transport properties of vdW layered materials. Unraveling the complex atomistic dynamics and structural evolution at vdW surfaces is therefore critical for the design and synthesis of the next-generation vdW layered materials. Here, we show that Ge/Bi cation diffusion along the vdW gap in layered GeBi2Te4 (GBT) can be directly observed using in situ heating scanning transmission electron microscopy (STEM). The cation concentration variation during diffusion was correlated with the local Te6 octahedron distortion based on a quantitative analysis of the atomic column intensity and position in time-elapsed STEM images. The in-plane cation diffusion leads to out-of-plane surface etching through complex structural evolutions involving the formation and propagation of a non-centrosymmetric GeTe2 triple layer surface reconstruction on fresh vdW surfaces, and GBT subsurface reconstruction from a septuple layer to a quintuple layer. Our results provide atomistic insight into the cation diffusion and surface reconstruction in vdW layered materials.

ANALYSIS OF EXISTING METHODS FOR CALCULATING THE POSITION OF BOUNDARY COLUMNS

The purpose of the research is to improve the methods of calculating the position of limit posts on the railways of Ukraine. To achieve the established goal, a comprehensive analysis of the existing methods of determining the position of boundary posts was performed, taking into account the multivariate design features of the railway track connection and compliance with traffic safety requirements. Methodology. In the process of research, methods of analysis and synthesis were used to study the content and basic provisions of existing methods for determining the position of limit posts on railways; methods of analytical geometry to describe the position of the limit column relative to adjacent tracks, taking into account the geometric parameters of the rolling stock. The results. As a result of the conducted research, the following conclusions were obtained. The basis of the current methods of determining the position of the limit posts are the requirements for the parameters of the calculation car, which is not operated on the railways of Ukraine, however, the recalculation of the position of the boundary columns on the existing tracks of the main and industrial railway transport using the characteristics of the car that will replace the existing calculation car is currently impractical and irrelevant Taking into account the multivariate constructions of the connection of railway tracks, there is no universal analytical solution for determining the position of the limit column. New approaches to determining the distribution of the overall distance when calculating the position of the limit posts in the conditions of automated design have inaccuracies, and also do not take into account the variety of structural features of the connection of railway tracks. The results of the performed analysis are the basis for continuing research on improving the methods of calculating the position of limit posts on the railways of Ukraine. Scientific novelty. The obtained results make it possible to summarize the scientific basis for the imperfection of the existing methods of calculating the position of the limit posts on the railways of Ukraine. Practical significance. From a practical point of view, the results of the analysis create conditions for further research on the improvement of the above methods. The result of the research should be the development of a universal method of theoretically accurate calculation of the position of the limit post or other objects on railway tracks for any design of track development. The use of this method in design practice is possible by developing a software product for determining the position of the boundary column, including on tracks with a width of 1435 mm, for cases where tracks with a width of 1435 and 1520 mm are combined on the same ground surface and under the condition of using calculated wagons with any parameters.

Pengembangan Model Perbaikan dan Peningkatan Kekuatan Struktur Sambungan Balok-Kolom pada Bangunan Pasca Gempa

This paper presents an experimental study on repairing damaged beam-column reinforced concrete joints using carbon fiber reinforced polymer (CFRP). The test objects were in the shape of the letter T which represented the beam-column connection. The test object came from the previous research which had been failure. The retrofitted action includes strengthening the column position, injection with concrete glue and adding CFRP. Two kinds of CFRP were use, CFRP sheets (EB) and CFRP strips (NSM). The integrity of concrete after injection were tested with Ultrasonic Pulse Velocity (UPV). The retrofitted specimens were tested in loading frame to occurred strength, stiffness and ductility for each kind of retrofitted action. Three kind of tested were held, bending in one direction, shearing in one direction, and quasi cyclic bending. The selection test adjusted to the damage history of specimen.

Characteristics of “Daikoku‐bashira” and atrium of townhouses in Takayama—Correlation between the dimensions and position of the maximum section column and atrium

AbstractThe maximum section column of townhouses in Takayama can be classified into type A [earthen floor type] and type B [living space type]. The dimensions of maximum section columns tended to increase as the plane scale increased and the frontage widened. The atrium area tended to expand in the early Meiji period. We observed that the form of a maximum section column standing in one straight line at a rectangle atrium became the form of a maximum section column standing crossing‐axis in the plane of the structure of ridge direction and the span at irregularly shaped atrium, together complicating the plane and atrium shapes.

Benchmark Tests of Atom Segmentation Deep Learning Models with a Consistent Dataset.

The information content of atomic-resolution scanning transmission electron microscopy (STEM) images can often be reduced to a handful of parameters describing each atomic column, chief among which is the column position. Neural networks (NNs) are high performance, computationally efficient methods to automatically locate atomic columns in images, which has led to a profusion of NN models and associated training datasets. We have developed a benchmark dataset of simulated and experimental STEM images and used it to evaluate the performance of two sets of recent NN models for atom location in STEM images. Both models exhibit high performance for images of varying quality from several different crystal lattices. However, there are important differences in performance as a function of image quality, and both models perform poorly for images outside the training data, such as interfaces with large difference in background intensity. Both the benchmark dataset and the models are available using the Foundry service for dissemination, discovery, and reuse of machine learning models.