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Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The primary objective of this study is to precisely characterize the behavior of double bracket-to-circular Hollow Section (CHS) column joints due to combined internal forces resulting from double tensile loading in opposite directions. In order to accomplish this goal, an experimental program consisting of eight test specimens has been carried out and numerical finite element modeling has been employed for the same specimens to analyze the stresses and deformations that occur within the vicinity of bracket-to-CHS joints. A total of 15 finite element models were constructed to simulate the initial study, addressing boundary conditions and facilitating verification and results comparison. The study included an investigation of various parameters, including the spacing between brackets in the longitudinal direction, as well as the depth-to-thickness ratio of the CHS columns and adding a T-stiffener to the bracket configuration. The study determined that an increase in the diameter-to-thickness ratio of the CHS columns significantly reduced the overall strength of the joint. Furthermore, findings suggested that increasing the longitudinal spacing between brackets resulted in an increase in single-bracket joint strength and a minor reduction regarding joint strength considering the effect of line loading. Moreover, adding a T-stiffener shape for the brackets enhanced the joint strength and prevented bracket tip fracture. In addition, a distinct behavior arises when considering joints with positive eccentricity, where the forces' line of action extends beyond the circular cross-section of the CHS. In such cases, a reduction in joint strength is observed. Finally, a modification factor "A" is applied to the X-type branch plate-to-CHS strength equation presented by the AISC360-22 to account for the longitudinal spacing between brackets. [ABSTRACT FROM AUTHOR]

The screw, a critical element in a variety of transmission mechanisms, significantly influences the performance of the transmission process. Accurate measurement of screw lead is crucial for ensuring the quality of transmission equipment. However, the measurement process can be affected by the precision limits of the measuring instruments and the challenges of manual fine adjustments. This can lead to the screw being misplaced, introducing errors due to the off-center positioning of the workpiece. Such errors can hinder the achievement of high-precision measurements. This research aims to reduce the time needed to adjust for workpiece misalignment and to improve the accuracy of screw lead measurement through error compensation. This study starts by examining two specific scenarios that can cause workpiece misalignment in screw lead accuracy measurements: the tilting of the workpiece and the misalignment of the workpiece axis relative to the circular grating axis. Then, a mathematical model to quantify this misalignment and measure the associated parameters is developed. Based on the measured parameters, a computational model is established to compensate for the bias error under these conditions. This method allows for efficient and precise measurement of the screw lead even when the workpiece is not perfectly aligned. Calibrated screws and a digital micrometer are used to conduct experiments on workpiece misalignment. By comparing measurements with and without error compensation, the effectiveness of the compensation method in enhancing measurement accuracy is demonstrated. [ABSTRACT FROM AUTHOR]

Beam-column joints' behavior is a key research focus due to their critical role in maintaining structural integrity and safety during earthquakes. While concentric joints have been extensively studied, eccentric joints, where beams' centerlines deviate from columns' centerlines, remain relatively unexplored. Beam-column joints exhibit more complex behavior, experiencing a significantly higher shear force (approximately six-fold that of a column), along with flexural moments and normal forces. The joint's eccentricity introduces a torsional moment that amplifies shear stress, and the beam is subjected to an out-of-plane moment (around one-sixth of the primary moment). The out-of-plane moment reduces the joint's resistance mechanism by reducing the confinement provided by beams. To examine the influence of beam eccentricity on the ductility, strength, and failure mechanism of beam-column joints, comprehensive nonlinear finite element (FE) analyses were conducted utilizing experimental eccentric beam-column joints, followed by meticulous validation of the developed model. The models employed incompatible mode mesh element and energy-based models for the concrete material behavior, utilizing an explicit solver. The models were used to examine the impact of various geometric parameters, boundary conditions, and axial load levels on behaviors (global and local) of the beam-column joint subassemblies. The examined geometric parameters encompass aspect ratios of joint and column for both joint types (exterior and interior). Joint behaviors were observed to be significantly influenced by the boundary conditions of the column. Furthermore, the aspect ratio of the joint, representing the beam-to-column depth ratio, played a predominant role in determining the joint failure mechanism by limiting their ability to develop beam hinges. Increasing the aspect ratio of the column had a modest effect on the joint's shear strength but improved the joint subassemblies' ductile behavior, despite increasing the joint's torsional moment. Higher column axial load levels increased the joint's shear strength and led to a shift in cracking patterns from diagonal to vertical. Interestingly, the study found that interior joints experienced higher out-of-plane moments. Exterior and interior joints maintained a level of approximately 62.5 % as a ratio between their shear strength across all models. Moreover, it was observed that yielding of joint stirrups correlated with a shear distortion angle of approximately 0.5 × 10 − 2 rad. Restrictions of ACI provisions on the aspect ratio of the joint seem to be conservative for eccentric interior joints. On the other side, the ACI provisions might overestimate eccentric exterior joint shear strengths as the aspect ratio exceeds unity. [ABSTRACT FROM AUTHOR]

This paper provides an in‐depth study of the winding mechanical properties in generators under rotor interturn short circuit (RISC) cases. Unlike previous studies, this research investigates not only the influence of RISC degrees, but also the RISC positions and the eccentricity on the winding mechanical properties. The electromagnetic force (EF) formulas as well as the electromagnetic‐structure coupling model are first proposed to derive the mechanical winding response characteristics, such as the vibration, deformation, the strain, and the stress. Subsequently, both finite element analysis (FEA) and experimental investigations are conducted to validate the theoretical findings. The results reveal that RISC introduces additional harmonics to the EF. Furthermore, as the eccentricity/RISC degree or the distance between the short circuit position and the N‐pole increases, the end winding vibrations become more pronounced. When comparing single eccentricity and RISC faults to cases where both faults occur simultaneously, it is observed that the combined faults have a more detrimental impact on the end winding mechanical properties. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The mechanical properties and insulation damage of stator end windings in permanent magnet synchronous generator (PMSG) are investigated by theoretical analysis, finite element analysis (FEA) and experiment verification. First, a theoretical model of the winding electromagnetic force (EF) and vibration response before and after eccentricity faults are established. Then, the stress/strain distribution of the end windings under different working conditions is analyzed. Finally, the insulation damage behavior of end windings with initial cracks is studied and characterized using the stress intensity factor (SIF). The results indicate that the winding EF and vibration responses vary under different faults. The stress/strain at the joint of the winding is the largest, and the insulation layer has the maximum stress/strain under the same section. Additionally, the SIF amplitude of the crack at the winding joint is the largest. And the SIF amplitude of the crack will increase with the increase of fault degree/crack depth/crack length. The contribution of this paper lies in the comprehensive analysis of the winding EF distribution, vibration response, stress and strain, and insulation damage before and after eccentricity. This analysis can provide valuable reference for the health monitoring of PMSG eccentricity faults and the prevention of winding insulation damage. [ABSTRACT FROM AUTHOR]

An Axial Piston Pump (APPs), suitable for high pressure and high efficiency, is used as the source of fluid power in the hydraulic system. Due to the compact design and relative motion between various parts, it causes wear in parts thus leakage introduce between various moving parts which work under tight tolerance. Multiple faults in an axial piston pump occur simultaneously after a long time of operation due to harsh working conditions and heavy loads. Faults in the pump deteriorate the pump's performance and limit the operating range of the pump. Estimation must account for random and uncertain characteristics, and accurate wear prediction is difficult. Effective diagnosis improves pump dependability and performance. An approach based on simulation is utilized to model the impact of faults like leakage through eccentricity in piston-cylinder arrangement with increasing severity of clearance between piston-cylinder arrangement and its effect on the pump performance. As the clearance with different eccentricity between the piston and cylinder arrangement increases, outlet pressure and discharge of the pump remains unaffected up to a critical value of severity. After further increasing severity, outlet pressure and discharge reduce monotonically and saturate at a single value in extremely severe conditions. With increasing the severity of eccentricity in the piston-cylinder arrangement and increasing the severity of clearance, a critical threshold value shifts to a lower magnitude. [ABSTRACT FROM AUTHOR]

AbstractThe eccentricity index of a graph is the sum of the eccentricities of all vertices in the graph. A segment S of a tree T is a subgraph isomorphic to a non-trivial path where all internal vertices have degree 2 in T and the end-vertices are branching vertices or leaves. The segment sequence of a tree is the sequence of the lengths of all segments in a tree. In this paper, we characterise trees of a given segment sequence with minimum eccentricity index. We show that in the family of trees of a given segment sequence, the tree with minimum eccentricity index is the unique ‘starlike’ tree (a tree with one branching vertex). [ABSTRACT FROM AUTHOR]

In the measurement of residual stresses (RSs) via the hole-drilling method, the error induced by the eccentricity of the drilled hole is inevitable and non-negligible in some cases. In this study, both the eccentricity coordinates and RS state (two principal stresses and one principal angle) are considered unknowns that must be solved. A set of five equations is required to determine these five unknowns. Therefore, two additional measuring grids are added to the strain gauge comprising three grids, which is typically used in measuring RSs. Consequently, a novel strain gauge rosette with five measuring grids (SGR-5MG) is created. Subsequently, an algorithm associated with the SGR-5MG is developed to solve the five unknowns based on the Newton–Raphson method. The algorithm is elasticity-based and derived according to the layout of the SGR-5MG. Finally, the proposed method is verified numerically and experimentally. The results show that (1) the eccentricity error is up to 35.1% when the eccentricity reaches 0.05 D, where D represents the diameter of the gauge circle; (2) Using the proposed method, the error can be significantly reduced to 7.2%; (3) The elasticity-based proposed method cannot make the predicted results exactly converge to the actual stresses in predicting high stresses because of the plasticity deformation around the hole. The eccentricity error can be reduced significantly by using the proposed method based on the SGR-5MG. [ABSTRACT FROM AUTHOR]

For a given graph G, the second Zagreb eccentricity index ξ 2 (G) is defined as the product of the eccentricities of two adjacent vertex pairs in G. This paper mainly studies the problem of determining the graphs that minimize the second Zagreb eccentricity index among n-vertex bipartite graphs with a fixed number of edges and diameter. To be specific, we determine the sharp lower bound on the second Zagreb eccentricity index over the bipartite graphs of order n in terms of fixed edges and diameter. The extremal graphs attaining these lower bounds are fully characterized. [ABSTRACT FROM AUTHOR]

The topological index is just one of several very useful tools that graph theory has made available to chemists. Topological indices are invariants of real numbers under graph isomorphisms. Several topological indices have been defined. Some of them are used to model chemical, pharmaceutical and other properties of molecules. The eccentric connectivity index (eci) is also a topological index. The eci of G, denoted by 휀c(G), is defined as 휀c(G) =∑ v∈V (G)deg(v)e(v), where deg(v) represents the degree of a vertex v and e(v) is its eccentricity. In this paper, exact formula for the eci of complementary prisms is derived. [ABSTRACT FROM AUTHOR]

Effects of eccentricity and horizontal electric field (EH) on the binary‐collision outcomes of water drops are examined using numerically calculated collision characteristics from previous studies and results of simulation experiment conducted by the authors. For a fixed collision kinetic energy (CKE), filament breakups can occur at all values of eccentricity but events of coalescence decrease, and that of sheet breakup increase with increasing eccentricity in absence of EH. However, as EH increases to ∼300 kVm−1 it opposes the variability of the coalescence and sheet breakup events with eccentricity. When EH exceeds ∼300 kVm−1 the collision outcomes might be determined only by the CKE and EH. The calculated value of coalescence efficiency and total number of fragments after a binary collision decreases with an increase in EH. It is argued that an electric field can significantly modify drop size distribution in thunderclouds and needs to be considered for development of precipitation. Plain Language Summary: Growth of water drops in clouds is mostly governed by the drop size distribution in them. When two drops collide with each other, they can either coalesce to form a single larger drop, or disintegrate into many smaller drops, or bounce back. These different outcomes after their collisions are mostly determined by whether the collisions are centric where the eccentricity of the collision is zero or grazing where the eccentricity is one or somewhere in between the two extremes. The present study shows that if the collisions occur in presence of a horizontal electric field, it opposes the effect of eccentricity on the outcomes of the collisions. In this study, simultaneous effects of eccentricity and horizontal electric field are examined from numerically calculated collision characteristics from previous studies and utilizing the results of a simulation experiment recently conducted by the authors. Simultaneous effects of eccentricity and electric field on coalescence efficiency and total and spectral size distribution of fragments generated after the collision have also been evaluated. The results suggest that the electric field can significantly modify drop size distribution in thunderclouds and need to be considered for the development of precipitation. Key Points: Horizontal electric field opposes the variability of coalescence/sheet breakup of water drops with eccentricity in binary collisionsNumber of fragments close to small (large) parent drop size decreases (increases) after collisions in the higher horizontal electric fieldBinary collisions in horizontal electric fields can substantially modify drop size distribution in thunderclouds [ABSTRACT FROM AUTHOR]

In several previous studies regarding foldable structures comprised of rods and knots, it has been usual to simplify their geometry to lines and points respectively. However, this study assumes that the dimensions that these elements necessarily acquire (due to their material condition) constitute an important issue in the folding and unfolding process. To test this hypothesis, the research first defines the concept of kinetic range and its various variants and studies how variations in the radius of the rods, the eccentricity of the knots and the opening angle influence this parameter. Furthermore, this study will demonstrate that this parameter is extensible to bar bundle systems and scissors systems and finally will verify that the results obtained by using algorithm-driven models are also verifiable by mathematical methods and experimentation using physical models. As a result, the methodology followed in this article allows the inclusion of a comparative table that classifies the performance of the structural systems studied in order to establish which is the optimum in relation to their kinetic range. [ABSTRACT FROM AUTHOR]

Concrete reinforced by textile composite materials has long been a focus of substantial interest in the engineering applications. In this paper, the compression performance of concrete cylinders confined by carbon fibers, glass fibers, and carbon–glass hybrid triaxial woven fabric composites under three different eccentricities were investigated. Moreover, the digital image correlation analysis method was introduced to observe the compression process and failure modes of reinforced concrete cylinders. Meanwhile, the strain process of yarns during the failure was also analyzed. The result showed that all of triaxial woven fabric composites can increase the strength of concrete cylinders, while the strength decreased with the increase of eccentricity and the mechanical performance converged gradually. In addition, using triaxial woven fabric composites made of glass fibers can promote the ductility of concrete cylinders. It also indicated that employing carbon–glass hybrid triaxial woven fabric composites can not only have the advantages of increasing the strength and ductility of concrete cylinders, and low cost, but also effectively reduces the eccentric sensitivity. [ABSTRACT FROM AUTHOR]

Cold-formed steel channel (CFSC) sections have gained widespread adoption in building construction due to their advantageous properties, including superior energy efficiency, expedited construction timelines, environmental sustainability, material efficiency, and ease of transportation. This study presents a numerical investigation into the axial compressive behavior of CFSC section columns. A rigorously developed finite element model for CFSC sections was validated against existing experimental data from the literature. Upon validation, the model was employed for an extensive parametric analysis encompassing a dataset of 208 CFSC members. Furthermore, the efficacy of the design methodologies outlined in the AISI Specification and AS/NZS Standard were evaluated by comparing the axial load capacities obtained from the numerically generated data with the results of four previously conducted experimental tests. The findings reveal that the codified design equations, based on nominal compressive resistances determined using the current direct strength method, exhibit a conservative bias. On average, these equations underestimate the actual load capacities of CFSC section columns by approximately 11.5%. Additionally, this investigation explores the influence of eccentricity, cross-sectional dimensions, and the point-of-load application on the axial load capacity of CFSC columns. The results demonstrate that a decrease in section thickness, an increase in column length, and a higher degree of eccentricity significantly reduce the axial capacity of CFSC columns. [ABSTRACT FROM AUTHOR]

The total eccentricity index of a connected graph is defined as sum of the eccentricities of all its vertices. In this paper, we give the sharp upper bound on the total eccentricity index over graphs with fixed number of pendant vertices and the sharp lower bound on the same over graphs with fixed number of cut vertices. We also provide the sharp upper bounds on the total eccentricity index over graphs with s cut vertices for s = 0 , 1 , n - 3 , n - 2 and propose a conjecture for 2 ≤ s ≤ n - 4 . [ABSTRACT FROM AUTHOR]

Abstract The primary objective of this study is to precisely characterize the behavior of double bracket-to-circular Hollow Section (CHS) column joints due to combined internal forces resulting from double tensile loading in opposite directions. In order to accomplish this goal, an experimental program consisting of eight test specimens has been carried out and numerical finite element modeling has been employed for the same specimens to analyze the stresses and deformations that occur within the vicinity of bracket-to-CHS joints. A total of 15 finite element models were constructed to simulate the initial study, addressing boundary conditions and facilitating verification and results comparison. The study included an investigation of various parameters, including the spacing between brackets in the longitudinal direction, as well as the depth-to-thickness ratio of the CHS columns and adding a T-stiffener to the bracket configuration. The study determined that an increase in the diameter-to-thickness ratio of the CHS columns significantly reduced the overall strength of the joint. Furthermore, findings suggested that increasing the longitudinal spacing between brackets resulted in an increase in single-bracket joint strength and a minor reduction regarding joint strength considering the effect of line loading. Moreover, adding a T-stiffener shape for the brackets enhanced the joint strength and prevented bracket tip fracture. In addition, a distinct behavior arises when considering joints with positive eccentricity, where the forces’ line of action extends beyond the circular cross-section of the CHS. In such cases, a reduction in joint strength is observed. Finally, a modification factor “A” is applied to the X-type branch plate-to-CHS strength equation presented by the AISC360-22 to account for the longitudinal spacing between brackets.

Abstract In this population-based observational cross-sectional study, we investigated retinal peripheral refraction in Chinese adults with myopia. We categorized 1511 Chinese adults with myopia (18 − 55 years) into low (LM), moderate (MM), and high myopia (HM) groups. Axial length, central corneal thickness, steep keratometry, flat keratometry, and intraocular pressure were measured. Refractive difference values (RDVs) for different eccentricities (RDV0–53) and the superior (RDV-S), inferior (RDV-I), temporal (RDV-T), and nasal (RDV-N) retinal regions were measured using multispectral refractive topography. The hyperopic defocus was higher for the MM group than for the LM group in RDV20–53, RDV-S, and RDV-T and HM group in RDV20–53, RDV-S, RDV-T and RDV-N. The hyperopic defocus was higher for the HM group than for the LM group in RDV20-53, RDV-S and RDV-T but lower for the LM group in RDV-N. RDV-N decreased with age (R2 = 0.0191, slope = − 0.01, p

The mechanical properties and insulation damage of stator end windings in permanent magnet synchronous generator (PMSG) are investigated by theoretical analysis, finite element analysis (FEA) and experiment verification. First, a theoretical model of the winding electromagnetic force (EF) and vibration response before and after eccentricity faults are established. Then, the stress/strain distribution of the end windings under different working conditions is analyzed. Finally, the insulation damage behavior of end windings with initial cracks is studied and characterized using the stress intensity factor (SIF). The results indicate that the winding EF and vibration responses vary under different faults. The stress/strain at the joint of the winding is the largest, and the insulation layer has the maximum stress/strain under the same section. Additionally, the SIF amplitude of the crack at the winding joint is the largest. And the SIF amplitude of the crack will increase with the increase of fault degree/crack depth/crack length. The contribution of this paper lies in the comprehensive analysis of the winding EF distribution, vibration response, stress and strain, and insulation damage before and after eccentricity. This analysis can provide valuable reference for the health monitoring of PMSG eccentricity faults and the prevention of winding insulation damage.

Mstislav Dobuzhinsky’s illustrations to the tale by Yury Olesha The Three Fat Men have not received a convincing interpretation. It is suggested to read these illustrations as a special work with the social imaginary that expands the participation of the fairy tale’s characters in revolutionary events through a special gaze technique. Two types of imagination are distinguished: the narrative imagination, implying the acceptance of the structure of an event, and the eccentric imagination, in which the event requires immediate action. This distinction is rooted in the practices of political rhetoric and was internalized by Olesha himself from his experience with European prints and decals. The magic of decals is essential to the plot of his fairy tale, but even more so to Dobuzhinsky’s pictorial program. Dobuzhinsky uses unusual avantgarde angles, framing, the view from the protagonist’s perspective and the meeting of views, drawing, among other things, on images of knowledge in European utopias. Referring to the philosophical concepts of the gaze, it is possible to reconstruct the system of empathy, sympathy for the characters and their eccentric actions, which Dobuzhinsky’s illustrations are meant to evoke. When reading Olesha’s tale, we follow the twists and turns of the narrative; when looking at the illustrations, we realize how each character contributes to the unusual development of events and how the meeting of gazes can establish a new social order. Dobuzhinsky does not simply interpret Olesha’s tale, but plays it out, engaging readers in an interactive game.

This article establishes a three-dimensional fluid-structure interaction (FSI) model for reciprocating rod seals. Based on this model, a novel method using a two-dimensional FSI model to solve the average sealing performance across multiple sections is proposed for the first time. This method allows for the dimensional reduction of solid mechanics, contact mechanics, and fluid mechanics analysis. The performance of the sealing system was calculated and analyzed under static eccentricity (which does not change with piston rod motion) and dynamic eccentricity (which changes with piston rod motion) using the aforementioned models. The results indicate that the sealing performance calculated by both models is highly consistent, demonstrating that, within the permissible engineering limits, the two-dimensional FSI model can replace the three-dimensional model, thereby reducing computational costs and improving convergence. Additionally, the results show that eccentricity increases the friction and leakage rates of the sealing system, with dynamic eccentricity having a greater impact on sealing performance than static eccentricity due to the viscoelasticity of the rubber. [ABSTRACT FROM AUTHOR]

Objective In the 9 m level large-diameter shield tunneling, there are no engineering cases using shield method for constructing connecting passages yet. Due to the influence of clearance and evacuation platform height, a certain eccentricity exists between the connecting passage and the main tunnel, resulting in the impact of shield launching and receiving with eccentricity for main tunnel structure. It is necessary to investigate the influence of different opening positions of shield method connecting passage on the internal forces of main tunnel segments. Method Based on a city railway project, numerical simulation method is used to analyze the mechanical response of main tunnel segments during the launching and receiving stages of above connecting passage construction under different eccentricity conditions. Result & Conclusion During the construction of shield method connecting passages, the most critical stage is when the thrust acting on the shield reaction frame is zero. As the eccentricity increases, the convergence deformation of special segments in main tunnel and the internal forces in steel and concrete segments gradually decrease, while the circumferential and longitudinal shear forces gradually increase. The internal forces in ordinary concrete segments adjacent to the special segments on the opening side also increase significantly, which requires special attention in structure design.

The paper investigates the behavior of glass‐fiber reinforced polymer (GFRP) reinforced concrete columns with integrated steel spirals (hybrid reinforcement). Six concrete columns were tested under eccentric axial loading, resulting in failure due to bending. Columns with outer steel longitudinal bars experienced steel yielding at peak loads, while those with GFRP outer rebars failed due to concrete crushing. The results revealed that using GFRP as outer longitudinal bars led to peak loads 3–10% lower compared to columns with steel rebars. Inner confinement by steel spirals increased the load‐carrying capacity. Additionally, columns with inner tubular steel exhibited greater strength than those with steel spirals, indicating a slightly enhanced confinement effect. A finite element model was developed to analyze structural behavior, considering both material and geometric nonlinearity. The model's accuracy was validated by comparing predictions with test results. Parametric analysis from the nonlinear FE model showed that eccentricity significantly impacted column load‐carrying capacity. Increasing inner confinement area and the number of inner longitudinal bars improved structural stiffness and load‐carrying capacity. Furthermore, a simplified theoretical method was proposed. Comparison between experimental failure loads and theoretical predictions revealed differences within 20%, indicating satisfactory reliability of the proposed method. [ABSTRACT FROM AUTHOR]

In this paper, we analyze and interpret light curves obtained by observing with the HST telescope the transit of exoplanet HD 189733b across the disk of the star. Observations are carried out in a wide wavelength range of 5500–10 500 Å, which makes it possible to identify the relation between the wavelength and the data obtained during the interpretation of the radius of the planet. It is also shown that this dependence can be explained by the presence of a Rayleigh atmosphere on the planet while the possible parameters of this atmosphere are also approximately estimated. [ABSTRACT FROM AUTHOR]

The friction loss caused by the oil-free operation of miniature oil-free rolling piston compressor can not be ignored. Therefore, it is important to know how to reduce the friction loss of miniature oil-free rolling piston compressor. For this purpose, a study was conducted on the friction power consumption of the main friction pairs of miniature oil-free rolling piston compressor under varying operating conditions and structures. Firstly, a mathematical model for the dynamic analysis of miniature oil-free rolling piston compressor was established. Then, the force characteristics of the main components of the miniature oil-free rolling piston compressor were analyzed, and the variation law of the friction power consumption of the main friction pair with the spindle angle was calculated. Finally, the influence of exhaust pressure, slide thickness, eccentricity, and relative cylinder length on the friction power consumption and proportion of the main friction pairs in miniature oil-free rolling piston compressor were analyzed. The research results show that the discharge pressure of the miniature oil-free rolling piston compressor increase from 1 100 kPa to 1 800 kPa, and the total friction power consumption increase by 67. 7%, while the total friction power consumption only increase by 32. 8% . The eccentricity of the miniature oil-free rolling piston compressor increases from 0. 06 to 0. 2, and the total friction power consumption increase by 121. 5% . The relative cylinder length of the miniature oil-free rolling piston compressor increases from 0. 25 to 0. 6, and the total friction power consumption increase by 31. 9% . According to the analysis results, the most suitable eccentricity value for the miniature oil-free rolling piston compressor is around 0. 14. The optimized eccentricity has the most significant effect on improving the friction loss of the miniature oil-free rolling piston compressor followed by changing the thickness of the sliding plate, and finally changing the length of the corresponding cylinder. [ABSTRACT FROM AUTHOR]

The deg-centric graph of a simple, connected graph G, denoted by Gd, is a graph constructed from G such that, V (Gd) = V (G) and E(Gd) = {vivj: dG(vi, vj) = degG(vi)}. This paper introduces and discusses the concepts of deg-centric graphs and iterated deg-centrication of a graph. [ABSTRACT FROM AUTHOR]

The influence of the subgraph cloning operation on the graph diameter is studied. The corresponding potential increase in the diameter is estimated. Conditions under which the subgraph cloning operation causes no change in the graph diameter are formulated. An example of using the cloning operation to construct a family of fat trees is presented. The diameter of such graphs and the complexity of their design are estimated. [ABSTRACT FROM AUTHOR]

Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to reveal the mechanical behavior of short concrete columns reinforced with hybrid steel and glass FRP bars, 10 specimens were designed for eccentric compression tests. The effect of eccentricity and load–displacement/strain of the specimens was studied. Test results indicate that the damage process and failure mode of these hybrid RC columns was similar to those in the conventional steel-reinforced concrete columns. The mode of failure for all specimens is characterized as large eccentricity compression failure, and the ultimate bearing capacity of the columns decreases with the increase in eccentricity. However, the impact of the varying axial stiffness ratio between GFRP and steel bars on the bearing capacity can be considered negligible. In addition, based on theoretical analysis, two boundary states for distinguishing failure mode and the formulae for calculating ultimate bearing capacity in different failure modes of eccentrically loaded hybrid RC columns are proposed. The computed results agree well with test results. [ABSTRACT FROM AUTHOR]

The hole-drilling method is one of the most widespread techniques to measure residual stresses. Since the introduction of the Integral Method to evaluate non-uniform stress distributions, there has been a considerable improvement in the instrumentation technology, as step increments of about 10 microns are now achievable. However, that spatial resolution makes the ill-posedness of the problem stand out among other sources of uncertainty. As the solution becomes totally dominated by noise, an additional regularization of the problem is needed to obtain meaningful results. Tikhonov regularization is the most common option, as it is also prescribed by the hole-drilling ASTM E837 standard, but it has only been studied in the reference case of a hole with no eccentricity with respect to the strain rosette. A recent work by Schajer addresses the eccentricity problem by defining a correction strategy that transforms strain measurements, allowing one to obtain the solution with the usual decoupled equations. In this work, Tikhonov regularization is applied to the eccentric hole case through the influence functions approach, in order to avoid the introduction of new error-compensating functions and bias-prone interpolations. Some useful general considerations for a practical implementation of the procedure and an experimental test case on an aluminum specimen are presented. [ABSTRACT FROM AUTHOR]

Rotary plate vacuum pumps have become widely used as a source of vacuum for milking systems. The main features of a plate vacuum pump include design simplicity, high efficiency, low cost and adaptability to climatic conditions. A plate vacuum pump requires the improvement of specific performance indicators. This refers to the indicator of specific productivity and specific energy intensity. It is possible to improve the vacuum pump by optimizing the design parameters and technological models of operation. The known studies allow the establishment of rational geometric parameters, the number of plates, the ratio of the main dimensions and eccentricity. However, the problem of reducing the degree of uneven air pumping from the vacuum system needs a scientific solution. The use of a vacuum cylinder in a vacuum line of an increased diameter partially solves the problem of vacuum pressure fluctuations. But such a decision requires additional material costs. In addition, the power of a vacuum pump increases to compensate for the pressure losses. In this study, the authors proposed the design of a double-action plate vacuum pump. It was proven that the simultaneous operation of combined rotors with plates shifted by 45° decreased the degree of air pumping by 7.8%. The research results indicated that the productivity of the developed vacuum pump increased by 13.6%. The drive power increased by 12%, and the specific energy intensity was 20% lower than that of vacuum pumps with similar geometric parameters. The relationship between rational kinematic and design parameters of a double-action vacuum pump was established. [ABSTRACT FROM AUTHOR]

We study free vibrations of open noncircular cylindrical shells with elliptic cross sections. A computational model based on the finite-element method is developed. Numerical calculations were carried out for several versions of boundary conditions imposed at the ends. The numerical analysis makes it possible to establish the dependence of frequencies and the modes of free vibrations of noncircular cylindrical shells on the eccentricity of the elliptic cross section and the type of cutting of the shell. The obtained results are important for the evaluation of the load-carrying capacity of structural shell elements of the corresponding shape. [ABSTRACT FROM AUTHOR]

Radial drift of solid particles in the protoplanetary disk is often invoked as a threat to planet formation, as it removes solid material from the disk before it can be assembled into planets. However, it may also concentrate solids at particular locations in the disk, thus accelerating the coagulation process. Planetesimals are thought to drift much faster in an eccentric disk, due to their higher velocities with respect to the gas, but their drift rate has only been calculated using approximate means. In this work, we show that in some cases previous estimates of the drift rate, based on a modification of the results for an axisymmetric disk, are highly inaccurate. In particular, we find that under some easily realized circumstances, planetesimals may drift outwards, rather than inwards. This results in the existence of radii in the disk that act as stable attractors of planetesimals. We show that this can lead to a local enhancement of more than an order of magnitude in the surface density of planetesimals, even when a wide dispersion of planetesimal size is considered. [ABSTRACT FROM AUTHOR]

Recent Pauline scholarship has shown increasing interest in the concepts of agency, body, personhood, and self. Situating itself within an emerging current of Pauline interpretation of the σῶμα , this article provides an analysis of Paul's language concerning the σῶμα in Philippians 3:21. In the first part, we focus on Paul's description of the body as τῆς ταπεινώσεως , "of humiliation." It is argued that Paul conceives of the body in terms of its mortality, owing to its tendency towards death, as well as its monstrosity, a characteristic that illuminates how Paul reframes the perception of the body. In the second part, we analyze Paul's description of Christ's body as τῆς δόξης , "of glory." It is argued that the glorification of Christ's body emerges as a function of heavenly existence in God's presence. In our third part, we use the results from our preceding analyses of the language in Philippians 3:21 in order to construct a conceptual framework for interpreting the σῶμα in Paul from new interpretive angles. It is proposed that the concepts of fragility and eccentricity will shine more light on Paul's conception of the body, which has a twofold character as both fragile and eccentric. [ABSTRACT FROM AUTHOR]

Chemical graph theory deals with chemical graphs, which are used to represent chemical systems. Topological indices of molecular graphs are an important area of research in chemical graph theory. These indices are numerical values associated with compounds that aim to establish connections between chemical structures and physical attributes, chemical reactivity, and biological activity. Many graph polynomials have been proposed to compute various topological indices. Quantitative structure-property relationship (QSPR) analysis of chemical compounds involves several regression methods that rely on these topological indices. In this article, we utilize the newly introduced -polynomial to calculate the eccentricity-based indices such as the diameter eccentricity based and hyper diameter eccentricity based index values for nineteen linear saturated monocarboxylic acids. Quantitative structure-property relationship (QSPR) analysis is also performed for the seven thermodynamic properties of monocarboxylic acids. The relationship between thermodynamic properties and topological indices is explored using linear, quadratic and cubic regression models. The best fit curvilinear regression models were determined based on the R² and RMSE values of the models. To further investigate the statistical significance of our models, we also conducted chi-square goodness-of-fit tests to identify the best fit models. [ABSTRACT FROM AUTHOR]

A disconnected graph G is called a cluster if G is not union of K2s (1-factor) but union of complete graphs of order at least two. J. Akiyama, K. Ando and D. Avis showed in Lemma 2.1 of [2] that G is equi-eccentric if the eccentric graph Ge is a cluster or pK2. And they also characterized all graphs whose eccentric graphs are complete graphs and pK2 in [2]. In this paper, we determined in Theorem 2 all graphs whose eccentric graphs are clusters, which is an extension of Lemma 2.1 in [2]. [ABSTRACT FROM AUTHOR]

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Late Pleistocene glacial terminations are caused by rising atmospheric CO2 occurring in response to atmospheric and ocean circulation changes induced by increased discharge from Northern Hemisphere ice sheets. While climate records place glacial terminations coincident with decreasing orbital precession, it remains unclear why a specific precession minimum causes a termination. We compare the orbital and ice volume configuration at each precession minima over the last million years to demonstrate that eccentricity, through its control on precession amplitude, period and coherence with obliquity, along with ice sheet size, determine whether a given precession minimum will cause a termination. We also demonstrate how eccentricity controls obliquity maxima and precession minima coherence, varying the duration of glaciations. Glaciations lasting ∼100 thousand years are controlled by Earth's eccentricity cycle of the same period, while the shortest (20–40 ka) and longest (155 ka) occupy the maxima and minimums of the 400 thousand year eccentricity cycle. Plain Language Summary: The Milankovitch theory of the ice ages predicts that the growth and collapse of Pleistocene ice sheets is paced by the cycles in high latitude solar insolation that accompany variations in Earth's orbital motion. The orbital modes that dominate frequencies of incoming solar radiation are obliquity and precession, which operate at periodicities of approximately 40 and 20 thousand years, respectively. The dominant frequency at which ice sheets grow and collapse over the last million years is, however, approximately 100 thousand years, a closer match to eccentricity, an orbital period near absent from past solar radiation. Through a comparison between Earth's orbital configuration and an approximation of past global ice volume, we identify that the precession minima that trigger ice sheet collapse occur at distinct configuration of eccentricity and ice sheet size. In most cases terminations occur when precession minima align with obliquity maxima. We find that this coherence is influenced by the duration of precession cycles, which is in turn controlled by eccentricity. From these observations, we conclude that orbital eccentricity, through its control on both the amplitude and period of precession, paces the timing of glacial terminations and the size of Late Pleistocene ice sheets. Key Points: Late Pleistocene glacial terminations occur at distinct configurations of orbital precession, obliquity, eccentricity and ice volumeEccentricity controls the duration of precession cycles, and therefore the coherence of obliquity and precessionOrbital eccentricity, through its control on the amplitude and period of precession, paces Late Pleistocene glaciations [ABSTRACT FROM AUTHOR]

The paper presents a static analysis of the buckling and post-buckling state of thin-walled cold-formed steel (TWCFS) lipped channel section beam-columns subjected to eccentric compression. Eccentricity is taken into consideration relative to both major and minor principal axes. An analytical–numerical solution to the buckling and post-buckling problems is described. The solution is based on the theory of thin plates. Equations of equilibrium of section walls are derived from the principle of stationary energy. Then, to solve the problem, the finite difference (FDM) and Newton–Raphson methods are applied. Linear (buckling) and nonlinear (post-buckling) analyses are performed. As a result, pre- and post-buckling equilibrium paths are determined. Comparisons of the obtained numerical results, FE simulation results, and experimental test results are carried out and presented in comparative load-shortening diagrams. Additionally, a comparison of the buckling forces and buckling modes obtained from theoretical analysis and experiments is presented. [ABSTRACT FROM AUTHOR]

Bearing capacity tests were carried out on axially and eccentrically loaded coral concrete short columns reinforced with carbon-fibre-reinforced polymer (CFRP) bars. Parameters such as the ultimate bearing capacities and the stress in the CFRP bars and surface concrete were measured and analysed. All the columns failed due to the crushing of concrete in the compression zone. An increase in eccentricity not only decreased the ultimate bearing capacity, but also resulted in the shear fracture of CFRP longitudinal bars in the compression zone. In general, the stress of the longitudinal CFRP reinforcements in all specimens was quite low. The maximum stress of the CFRP bars in the columns was 105.78 MPa, just 23.5% of the ultimate compressive strength of the CFRP reinforcement. The superior bond between the CFRP bars and coral concrete conformed to the deformation coordination. A calculation method for the bearing capacity of CFRP-reinforced coral concrete short columns was developed and the calculated results were found to agree well with the test results. [ABSTRACT FROM AUTHOR]

An astronomical concept up to the eighteenth century, 'eccentricity' started to be used to refer to behaviours considered as odd, strange, rare, extravagant, etc. Once reified into a personality trait, it gained explanatory power. This not only increased its popularity but also facilitated its links with psychopathology and neuropsychology, and, via the shared concept of madness, with the notions of genius and creativity. This Classic Text describes the process whereby Alienism (Psychiatry) medicalized eccentricity. To this day, the latter remains firmly attached to 'psychoticism' and to some personality disorders. [ABSTRACT FROM AUTHOR]

The first degcity index DC1(G) of a connected graph G is defined as the sum of the terms [ex + ey] [dx + dy] over all the edges xy of G, where dx and ex represents the degree and eccentricity of a vertex x in G respectively. In this article, we have obtained some lower and upper bounds of first degcity index. [ABSTRACT FROM AUTHOR]

A topological index is a numerical invariant which depicts the properties of molecules in accordance to their chemical structure. For a given integer n > 0, if a graph G exists with a total eccentric index of ζ(G) = n, then "n" is said to be total eccentric graphical, which is kind of an inverse problem for topological indices. An (integer) interval [α,β] is called p-total eccentric (free) interval if for all n ∈ [α,β] there exists a (no) graph G(p, q) with ζ(G) = n. In this article, we determine several results for the existence and non-existence of total eccentric graphical intervals for graphs G on p vertices. [ABSTRACT FROM AUTHOR]

When it comes to solar thermal power systems, a latent heat energy storage unit is one possible solution to the imbalance in supply and demand. On a shell‐tube type heat storage system, computational and experimental research was done to determine how to charge a heat storage system using honeybee wax‐biodegradable phase change material. This paper examines the impact of single, double, and triple inner heat transfer fluid tubes on the melting properties of bee wax in relation to vertical and horizontal eccentricity. Through the experimental examination of a lab‐scale prototype, the computational model was verified. A computational model was used to investigate the impact of eccentricity on different configurations for the melting process. Utilizing multiple tubes significantly shortened the charging time, according to the system analysis. In a vertically downward direction, melting time reduced as eccentricity increased. Compared to the single tube concentric case, the maximum melting time reduction for the single‐, double‐, and triple‐tube cases was 63.7%, 67.0%, and 68.34%, respectively. [ABSTRACT FROM AUTHOR]

Existence of moment or eccentricity is a common loading situation; thus, it is necessary to be totally aware of the circular footing bearing capacity subjected to eccentric load to design economically. This paper presents a design chart for transforming a circular footing under eccentric load into an equivalent rectangular footing, allowing the use of existing bearing capacity formulas. A new "effective area" is defined, and characterized by a uniform soil pressure distribution. Unlike previous methods, the paper fully describes the calculation process for this area. The results show significant differences in the dimensions of equivalent footings compared to older methods, especially in designs with low eccentricities, leading to higher bearing capacities. Additionally, the dimensions of the "contact area," which fully interacts with the soil, are derived to ensure compliance with building codes. Finally, simple mathematical expressions for eccentricity reduction factors are provided for both drained and undrained conditions. [ABSTRACT FROM AUTHOR]

Ring-shaped structures are widely used in engineering. However, their rotation axes are typically not coincident with the geometric axes, thus resulting in a rotational centrifugal force and significant vibration. This study focuses on the dynamic instability caused by constant and time-varying eccentricities. An analytical model is established using Hamilton's principle and the Galerkin method, in which the rotational centrifugal forces resulting from constant and time-varying eccentricities are incorporated. Based on this model, the effects of rotation, revolution, eccentricity ratio, and damping on instability behaviors are examined. The instabilities caused by constant eccentricity are predicted using eigensolutions, whereas those caused by time-varying eccentricity with single- and multifrequency components are estimated by applying the Floquét theory. The results show that the instability domains from the multifrequency eccentricity are not a simple superposition of those from the single-frequency eccentricity but contain more instability domains originating from their combinations. The instability suppressions imposed by damping and gyroscopic effects are compared. Finally, the instability domains from constant and time-varying eccentricities are verified via numerical calculations. [ABSTRACT FROM AUTHOR]

The paper proposes existing calculation methods and new designs of high-performance solid raft foundations with symmetric and non-symmetric cutouts (non-contact areas in the middle) in the bottoms for lightweight tower-type structures such as wind turbines, tower cranes, telecommunications aerials and others that are capable of taking significant eccentric loads with observance of the edge pressures on the soil base. An example of calculation for various alternate designs of tower crane foundations has been given, which shows the advantages of using foundations with a cutout in the bottom, ultimately leading to a significant saving in concrete consumption (over 50%) for the foundation depending on the design load on the soil base and its bearing capacity. [ABSTRACT FROM AUTHOR]

Objective The Lower Cambrian organic-rich shale is an important marine shale exploration target in western Hubei and southern Guizhou. Understanding the chronostratigraphic relationships and their underlying causes of organic-rich shale intervals in different areas is crucial for shale gas exploration. Methods In this study, we conducted cyclostratigraphic analyses using natural gamma-ray logging data from the Lower Cambrian well ND1 in western Hubei and the well HY1 in southern Guizhou and determined the primary astronomical periods. Using previously reported zircon ages as anchoring points, we constructed an astronomical time scale for the Lower Cambrian. Using a sedimentary noise model, relative sea-level changes in the Lower Cambrian were reconstructed. Results Our results reveal that wavelengths of 36 m and 9 m in well ND1 and 16.6 m and 4 m in well HY1 correspond to orbital 405 kyr and 100 kyr cycles, respectively. Furthermore, we calculated the durations of the Niutitang Formaion in well Niedi-1 and the Jiumengchong Formation in well HY1 to be 3.30 and 2.64 Myr, respectively, The astronomical age scales of two options are presented. In Option 1, the top of the Niutitang Formation in well ND1 serves as the starting point for the anchor point, with an age interval of 535.20±1.70 Ma to 538.50±1.70 Ma. Option 2 employs the top of the Jiumengchong Formation in well HY1 as the starting point of the anchor point, with the corresponding age interval spanning from 535.20±1.70 Ma to 537.84±1.70 Ma. Through correlation sea-level change curves (DYNOT and ρ1) with eccentricity cycles and sedimentary cycles, our results indicate that sea-level changes correspond to 1.2 Myr obliquity modulation cycles and two sedimentary sequences (SQ1 and SQ2). Comparing the total organic carbon (TOC) content of the Lower Cambrian organic-rich shale with orbital eccentricity, sedimentation rates, and sea-level changes, our findings reveal that the intervals with high TOC value correlate with the maximum eccentricity of 405 kyr, whereas those with low TOC value correspond to the minimum value in well ND1. In addition, the high TOC value corresponds to both the high sea level period and the low sea level period. Conclusions Because of the chaotic behavior of the solar system, accurately predicting the mechanism that drives organic-rich shale during the Early Cambrian is impossible. Assuming that the maximum eccentricity corresponds to the maximum organic carbon content at that time, strong seasonal variations have triggered the enrichment of black shale over a more extended period. Furthermore, the comparison between relative sea-level changes and organic carbon content reveals no causal relationship between sea-level fluctuations and the enrichment of organic matter. [ABSTRACT FROM AUTHOR]

Abstract Effects of eccentricity and horizontal electric field (EH) on the binary‐collision outcomes of water drops are examined using numerically calculated collision characteristics from previous studies and results of simulation experiment conducted by the authors. For a fixed collision kinetic energy (CKE), filament breakups can occur at all values of eccentricity but events of coalescence decrease, and that of sheet breakup increase with increasing eccentricity in absence of EH. However, as EH increases to ∼300 kVm−1 it opposes the variability of the coalescence and sheet breakup events with eccentricity. When EH exceeds ∼300 kVm−1 the collision outcomes might be determined only by the CKE and EH. The calculated value of coalescence efficiency and total number of fragments after a binary collision decreases with an increase in EH. It is argued that an electric field can significantly modify drop size distribution in thunderclouds and needs to be considered for development of precipitation.