bluuebunny/crossref_metadata_2025 huggingface dataset:
Response of structures to motions with fling step: Does fling matter?
Authors: Roy Rana , Mahajan Arindam , Pradhan Chandan
Published: December 2022

An essential signature of the near-fault motions is the fling-step, which contains a one-sided velocity pulse and ultimately results in permanent ground displacement. It is well-known that the standard processing of ground motion removes such fling. However, some researchers believe that dynamic action is hardly affected by such removal of permanent static displacement. So, such processed motions can be used to examine the effect of fling-step. In the current investigation, two mathematical analogues, rigid sliding and rigid rocking blocks are extensively studied under near-fault motions with fling-step. The response is computed using the processed motions (without explicit fling) and the processed motions with fling mathematically reintroduced. A comparison in response confirms that using motions without explicit fling is essentially deficient from a structural engineering perspective. The study has also noted the peculiarities in the dynamics of rocking oscillators, which may be of significance for assessing the consequences of the sequence of motions.
Closed-Form Derivation of Optimum Tuned Mass Damper Parameter Based on Modal Multiplicity Criteria
Authors: Patel V.B. , Jangid R.S.
Published: December 2022

It is presently established that properly designed tuned mass dampers (TMD) systems can effectively control the vibrations induced due to the wind and/or the seismicity. The TMD is one of the most used passive control systems in high-rise structural systems in an era of recent developments. The optimum parameters for the damped system to date require a numerical search technique or shootout technique, which is the trial-error method, of-course add complexity in selecting parameters obtained at optimality conditions. The study of optimum parameters based on modal multiplicity criteria showcases the complete closed-form solution, independent to another optimum parameter. The parameters presented in this study solely depend on structural damping and mass ratio. The derived optimum parameters are compared with the existing parameters in this field. This study also investigates parametric uncertainty for structural configuration under the harmonic excitation. To confirm its robustness under random vibration, various earthquake time history loads are applied to study the effect of structural displacement and acceleration response. In the end, the energy concept is deployed to explain how effectively the optimum TMD parameters help to reduce the kinetic energy, damping energy, strain energy, and input energy.
Seismic Assessment of Steel-frame Buildings Mounted with Base-Isolated System
Authors: Sharma Anurag , Tripathi R.K. , Bhat Govardhan
Published: December 2022

A multi-Storey steel frame building against earthquakes has always been a challenge for structural engineering and researchers. Many seismic protection systems have been investigated overtime where the Base Isolation system has widely been used and implemented. It works on the principle of dissociation of substructure to the superstructure. In the present paper, different multi-storey steel frame buildings are evaluated, which are mounted with Lead Rubber Bearing (LRB) as a base isolator. LRB has been designed in compliance with the FEMA and ASCE guidelines. Further, a relative study is presented for evaluating the traditional fixed-base structure with a base-isolated building by performing a time history analysis. Base shear, inter-storey drift, acceleration, and displacements are examined as a result of the study. The outcome shows significant contributions towards reducing acceleration, inter-storey drift and base shear distributed over the floors. Moreover, LRB not only absorbs the seismic energy but also substantially decreases the destructive effect during an earthquake.
Seismic Response Control of Structures with Stiffness Irregularities through Optimally Placed Active Tendons using Multiobjective Genetic Algorithm
Authors: Rather F. , Alam M.
Published: December 2022

This paper studied the seismic response control of structural building with stiffness irregularities through active tendon system (ATS) using Linear Quadratic Regulator control algorithm. The various responses considered are the floor displacements, story drifts, and base shear. The optimal number and the optimal position of these active tendons are obtained through multiobjective optimization using Genetic Algorithm to reduce the responses and the cost of the control system simultaneously. The conflicting objectives minimized are the base shear of the irregular building and the number of active tendons to be used. The maximum story drift and maximum floor displacement are used as constraints. For numerical results, six combinations of stiffness irregularity in critical storys 1,2,and 10 of a ten story defecient shear building frame subjected to El Centro earthquake is considered. The results show that the optimized control system is capable of keeping the responses of the building frame to an earthquake within permissible limits and stiffness irregularity in the same defecient frame cost only the tendon in atmost one additional story.
High-Rise Structure Parametric study to evaluate Cylindrical Charges on Blast Pressures
Authors: Ganesh Engammagari , Tiwari Naveen , Naharla Rohit , Ramana P.V.
Published: December 2022

The release of those materials would be contained within the facility’sboundariese so that the impact on the public would be negligible. Hazardous facilities include oil refineries, micro-chip manufacturing,g, etc. Basic Facilities: The buildings not classified as safety-critical or essential/dangerous come under this category. This paper investigates the effect of the cylindrical charge aspect ratio on the spatial distribution of sufficient pressure induced by blast blasting on the face of a concrete element. A clear pattern of the spatial distribution of internal pressure can be seen in the graphical comparison of different aspect ratios. This may be attributed to the complex pressure wave patterns produced by the detonation of cylindrical explosives. Adequate pressure decreases as the aspect ratio of the cylindrical head increases. A 50% reduction in clean printing is observed when the aspect ratio varies between 1 and 2.
Empirical Relationship between the Impact Energy and Compressive Strength for Slurry Infiltrated Fibrous Concrete (SIFCON)
Authors: Shelorkar A.P. , Jadhao P.D.
Published: December 2022

In this research, an empirical relationship between the impact of energy and compressive strength is developed using regression analysis. For this, simple, practical, and economical drop weight test was performed on Slurry Infiltrated Fibrous Concrete which was based on the testing procedure recommended by ACI committee 544. Hook ended steel fibre of 35 mm length and an aspect ratio of 60 was used as the reinforcing material in four different volume fractions such as 0%, 2%, 3% and 4% with water cement ratio of 0.4. The test results indicated that increasing volume fraction of fibre increased the impact resistance of concrete specimen. It is also found that the empirical relationship obtained from the regression analysis is accurate and preferable to evaluate the impact energy by using compressive strength of Slurry Infiltrated Fibrous Concrete thus eliminating the drop weight test.
Flexural fatigue lifeassessment of self compacting concrete containing recycled concrete aggregates by using probabilistic approach
Authors: Saini BabanpreetSingh , Singh S.P.
Published: December 2022

Present investigation has been conducted to analyze the fatigue life of self compacting concrete (SCC) containing different quantities of coarse fraction of Recycled Concrete Aggregates (RCA) by using probabilistic method. Three SCC mixes were prepared constituting 0%, 50% and 100% RCA. In total 165 beam specimens of size 100 × 100 × 500 (all dimensions in mm) were tested under fatigue loading in order to obtain fatigue life data at different stress levels. Static flexure test was also conducted on 126 beams prior to fatigue test. Fatigue life data have been modelled by using Weibull distribution method and subsequently distribution parameters were evaluated. Further, fatigue lives in terms of design fatigue life and theoretical fatigue life have been estimated by using the distribution parameters by employing probabilistic approach. It has been found that the design and theoretical fatigue life shows a significant reduction with the addition of RCA content. A decrease of 80-85 percent has been observed in the design and theoretical fatigue life when SCC has been made with RCA only. Substandard properties of RCA cause defects in the concrete by forming weak interfacial transition zone which degrades the fatigue performance of SCC containing RCA.
Properties of One-Part Alkali Activated Ground Granulated Blast Furnace Slag Using Slaked Lime as Alkali Activator – A Comparative Study with Different Silicate Sources
Authors: Sengupta J. , Dhang N. , Deb A.
Published: December 2022

The paper reports the results of investigating the prospect of using slaked lime as a solid activator to activate the ground granulated blast furnace slag (GGBFS) with micro-silica as an additive. The results of the above-mentioned one-part mix are compared to that of GGBFS activated with solid sodium silicate in combination with slaked lime and quick lime, discretely. The compressive strength is found to be comparable to that of slaked lime and sodium silicate activated GGBFS; the silica fume substitution is recommended at 10% with 5% slaked lime. The main hydration products are C-S-H and C-A-S-H. Although the setting is delayed, strength development is acceptable with curing at ambient temperature. The microstructural analyses conducted through Field emission gun scanning electron microscopy (FEGSEM) and X-ray diffraction (XRD) are in good correlation with the results obtained for strength development.
Pushover Analaysis of Irregular Tall RCC Structures
Authors: Verma Prashant , Madan S.K.
Published: December 2022

The paper is based on the study of the Response of Irregular Plan Tall RCC structures by Pushover Analysis in order to find the Base Shear, Pushover Curve, Performance limit, Shear force Diagrams, Bending Moment of the structure. Nonlinear Static Analysis, is also called as “pushover analysis”, and is also regarded as the most widely used analysis method for estimation of performance of Irregular tall RCC structures. Most of the significant Seismic Codes which proposes methods for seismic analysis of new or existing tall RCC Structures have been originally defined for simple regular structures.
Therefore the analysis of the seismic response of irregular Tall RCC Structures is difficult due to nonlinear and inelastic response of the structures and more difficult than that of regular structures. Most of the codes (IS 1893 (Part 1) 2016[1], ATC-40 1996[2], EC8-1 2004[3]) uses the concept of “regularity”, taking into account distribution of mass, stiffness and strength in the structures, both in plan and in elevation. But real structures seldom act in accordance with these regularity requirements, resulting in a narrowly dependable application of the basic non-linear static analysis.
For the study we are considering two G+19 storey T shaped and U shaped irregular tall framed RCC structures having height of 68 meters each and storey height of 3.3 meters. Pushover Analysis is carried out using shear walls at different locations in the structure. The objective of this study is to finds out which irregular plan tall structure is the most efficacious in resisting lateral loads. The software used for modelling and analysis is ETABS 2017.
Failure mechanisms and curvature radius effect in fixed ended flat oval LDSS slender column under axial compression
Authors: Sachidananda Khwairakpam , Singh KonjengbamDarunkumar
Published: December 2022

This paper presents the different failure mechanism of fixed ended flat oval LDSS (Lean Duplex Stainless Steel) slender column under axial compression by using the finite element software Abaqus. The load capacity is presented in terms of yield load and the deformation modes at ultimate load (?u) and post ultimate load at 1.5 ?u. Based on the deformation at ultimate deformation (?u) and post ultimate load at 1.5?u, failure mechanisms are identified as viz., 1) Local to local yielded buckling , 2) Local to local yielded flexural, 3) Flexural to flexural yielding , which ultimately depend on the slenderness of the column. The low slenderness column was found to have higher load capacity of column as compared to the higher slenderness column. The parametric effect of changes of curvature radius of cross-section on ultimate strength of column has also been presented showing the semi-circle section to have the highest strength.
Wind Interference Effect of Neighbouring Square Buildings in Rhombic Arrangement on an Octagonal Building
Authors: Kar R. , Dalui S.K.
Published: December 2022

Four square plan shaped tall buildings of the same height and lateral dimension are positioned at the vertices of a rhombus. The octagonal plan shaped tall building of same height is placed at the centroid of the rhombus. The wind-induced responses of the octagonal plan shaped tall building for specified interference cases are compared with that of the isolated cases. The octagonal plan shaped principal building is exposed to atmospheric boundary layer wind flow. The wind angle varies from 0° to 90° at an interval of 15° for both isolated and interfering conditions. Computational fluid dynamics is implemented to simulate the effect of wind-structure interaction on the principal and neighbouring buildings in the boundary layer wind flow. The wind-induced static responses like drag and lift coefficients, pressure coefficients for isolated and interference cases are evaluated and compared graphically. The responses of isolated and interference cases vary significantly with the varying wind incidence angle. The dynamic behaviour of wind is also thoroughly investigated to identify the adverse local effect on the different faces of the octagonal building. As the characterisation of wind-induced dynamic responses, peak pressure coefficients and power spectral densities are evaluated and plotted accordingly. The peak pressure coefficients are plotted against mean pressure coefficients. The power spectral densities for different interfering cases are compared with the isolated case. Significant variation in power spectral densities is observed in some cases, which portrays the different characteristics for formation and shedding of the vortices in the wake of the octagonal building. The comparison of various dynamic responses between isolated and interfering cases highlights the interference by the square plan shaped buildings.
Wind Induced Responses of Corner Modified Irregular Plan Shaped Tall Building
Authors: Mandal S. , Dalui S.K. , Bhattacharjya S.
Published: December 2022

The effectiveness of aerodynamic modification on a U plan shaped irregular tall building is depicted in this paper. The introduction of chamfer corner (25%) replaces the sharp corners of the building. Various wind direction ranging from 0° to 360° at an interval of 15° is considered to study the effect of wind direction by using Computational fluid dynamics (CFD) which simulate the wind environment around the building. Suitable grid size for simulation is obtained by using a grid independence study. The calculated structural response from the numerical analysis due to wind attack has been validated with the experimental values of a published article. The force coefficients and pressure coefficient has been extracted and compared considering the static effect of wind. The power spectral density of pressure on various points on the faces of the building has been plotted to indicate the dynamic behaviour of those building. The implementation of minor aerodynamic modification by chamfered corners lead to a better reduction in force coefficient. However, most of the cases more pressure has been attracted by the faces of those modified corners compared to unmodified sharp corner buildings. That indicated that the cladding design should be done with special care.
Performance of Different Bracing Patterns for Moderately Tall Steel Buildings Subjected to Lateral Load
Authors: Pandey S. , Bijoy B.
Published: December 2022

In the present work, a model of moderately tall steel building G+20 storied, has been developed and then analysed for lateral load using design software STAAD Pro. Performance of different types of bracing systems are checked under gravity load and wind load. Various results such as bending moment, shear force, lateral deflections, storey drift, axial load on columns are extracted from this analysis and studied meticulously. In few cases of brace pattern effect of providing eccentricity are also studied to suggest optimum positioning of these bracing systems.
Uplift Load Carrying Capacity of Cylindrical and Belled Pile in Cohesive soil Bed
Authors: Kumavat DevashishBabulal , Verma A.K. , Dalwadi B.R.
Published: December 2022

Foundation of some structures like transmission towers, mooring systems for ocean surface or submerged platforms, tall chimneys, jetty structures etc. are subjected to uplift loads. Literature reflects that scholars have conducted pull out field prototype and model test and failure pattern of soil is studied for belled piles in loess soil and cohesionless soil. In this research work, the authors have carried out 36 tests on single pile and pile groups and uplift load carrying capacity is obtained by experimental investigation of single pile, triangular pattern (2x1) and square pattern (2x2) using the model piles of cylindrical and belled shaped in cohesive soil of soft consistency. The piles are having 20 mm shaft diameter and varying L/d ratio of 6, 8,10,15,18 and 20 for both cylindrical pile and belled pile. Belled portion is cast in belled pile with an angle of 70° with horizontal and having base diameter of 60 mm and height 55 mm. Spacing between two piles in various pile group was kept three times the piles shaft diameter (3d) in all experiments. Based on the experimental results as the L/d ratio increases uplift load carrying capacity increases. Uplift load carrying capacity of single pile, triangular pile group and square pile group of belled pile is 410%, 280% and 240% more than cylindrical piles. Uplift load carrying capacity of triangular pile group and square pile group increases by 182% and 273% for cylindrical pile and 104% and 141% for belled pile in comparison with single pile. Failure pattern of soil is obtained from experiments performed on belled pile and by using this failure pattern, theoretical uplift load carrying of belled pile is obtained.Uplift load carrying capacity.
Structural Health Monitoring: GGBS – Foam concrete evaluation for Stress-Strain Characterization
Authors: Agnihotri Anamika , Ramana P.V.
Published: December 2022

Digital Image Processing (DIP) uses photogrammetry principles to monitor elements in space and attribute respective coordinates to a pre-set reference frame. The comparison makes the measure of a graphic collection taken above fixed intervals. The technique may be performed in many experiments, including compressive, longitudinal, torque, bending, and different combined loading for static and dynamic applications. As the world’s engineering structures (such as towers and highways) mature, there seems to be a critical necessity to maintain and analyse the integrity of the system of large buildings. As per the American Society of Civil Engineers (ASCE), there were 161,892 obsolete or technically deficient bridges in the U. S. as of 2008, with the mean lifespan of a bridge being 43 years old. The primary method used to assess deck integrity today is subjectively direct observation, which is unreliable since specific damage can be hard to spot, difficult to quantify visibly, or subject to individual perception. Bridges have lately been monitored using classic detectors like strain gauges and deflection indicators.
Seismic Response Control of Similar Adjacent Structures Connected by Maxwell Dampers
Authors: Patel C.C.
Published: December 2022

The seismic response analysis of dynamically similar adjacent structures connected by Maxwell dampers is studied. The structural response for four different types of earthquake ground motions is investigated. The formulation of the equations of motion for two adjacent multi-degrees-of-freedom structures connected with Maxwell dampers is presented. The dampers effectiveness is evaluated in terms of hte reduction of structural responses namely displacement, acceleration and base shear force of the connected adjacent structures. A parametric study is carried out to obtain the optimum damper parameter for minimum response of the connected structures. Results show that Maxwell damper is quite effective for seismic response control of either structure by selecting appropriate parameter of damper. Further, lesser damper at appropriate locations can significantly reduce the earthquake response of the connected system.
Dynamic Analysis of Laminated Composite One-fold Plates under Thermal Load
Authors: Das Sreyashi , Niyogi ArupGuha
Published: December 2022

In this research, free vibration analysis of epoxy-based laminated composite folded plate structures for thermal loads have been considered using finite element method. Eight noded isoparametric element with five degrees of freedom per node have been considered in the study. Folded plate formulation using 6 X 6 transformation matrix is applied to transform the element mass and stiffness matrices to global system matrices. Yang-Norris-Stavsky (YNS) theory along with rotary inertia have been used in the present formulation. Lamina material properties at elevated temperature have been used in the study. Parametric studies have been performed for laminated composite one-fold plate structure for various thicknesses, crank angle and fibre angle under different temperatures. Results reveal that rising thermal load reduces the stiffness of the structure considerably. As the presence of fold increases stiffness of the plate structures significantly, it can withstand increased temperature. Proper choice of fibre angle and thickness increases the stiffness of the structures thus making it more capable of resisting higher thermal load.
Mathematical Models Viability for Bi-Material Forte Appraisal
Authors: Meena Ayush , Bharti S.D. , Ramana P.V.
Published: December 2022

This study examines the mechanical traits of bi-material concrete containing polypropylene fiber. This analysis aims to establish a relationship between bi-material concrete’s compressive strength (CS), split tensile strength (STS), and flexural strength (FS). M25 grade of bi-material concrete is designed, and polypropylene fiber is added to half of the concrete. Polypropylene fiber (PPF) was included in concrete with 0.20, 0.35, 0.50, 0.75, 1.00, and 1.50% by the weight of cement. Different test (CS, FS, STS) was performed over the bi-material concrete after 28 days of the curing period. Mathematical models were made by performing regression analysis over the experiment data and matched with the other models in the previous studies. Mechanical properties of the definite increase when the polypropylene fiber increases up to 0.5% compared to conventional concrete. It is seen that the empirical values fall within reach of expected values when the predicted values are compared to the experimental results. In this study, the existing analytical models and the relationship between mechanical traits of bi-material concrete are evaluated and matched with the models present in previous studies, and a new model is proposed.
Hybrid Artificial Intelligence Network in Taxation of Upheaval Damaged Structures
Authors: Ramana P.V.
Published: December 2022

The knowledge base of the new ANN is reconstructed through the use of the Fuzzy Set Theory, which permits to formalization ion the procedures in a non-deterministic way. The uncertainty and the imprecision of the gathered data are managed with techniques topical to Fuzzy Logic. Moreover, the System permits the user to modify the same knowledge base or insert new basheadquartersd use the most appropriate one in specific situations. The gathered data and the evaluations' results are loaded on databases and databases, successively, for further elaborations and new evaluations with different knowledge bases. Implementing and fleshing out several psychological and neuroscience theories of cognition, the AI-ANN conceptual model aims at being a cognitive “theory of everything.” With modules or processes for perception, working memory, episodic memories, “consciousness,” procedural memory, action selection, perceptual learning, serial learning, deliberation, volition, and non-routine problem solving, the AI-ANN model is ideally suited to provide a functional ontology that would allow for the discussion, design, and comparison of AGI systems. The AI-ANN architecture is based on the cognitive cycle, a “cognitive atom.” The more elementary cognitive modules and processes play a role in each mental cycle. Higher-level functions are performed over multiple cycles. In addition to giving a quick overview of the AI-ANN conceptual model and its underlying computational technology, one can argue for the AI-ANN architecture’s role as a foundational architecture for an AGI. Finally, lessons For AGI researchers drawn from the model and its architecture are discussed.
Free Vibration Analysis of Stiffened Lock Gate Coupled with Reservoir Fluid considering Linearised Free Surface Condition
Authors: Singh DeepakKumar , Pal Priyaranjan
Published: December 2022

The effect of surrounding reservoir fluid on the stiffened lock gate structure is investigated using the finite element method. A single stiffener is used to stiffen the plate, which is placed edge to edge along the height on the plate's center nodal line. Mindlin’s plate bending and Euler’s beam theories are used to formulate plate and stiffener, respectively. The stiffened lock gate material is assumed to be isotropic, homogeneous, uniformly thick and elastic in nature. The fluid is assumed to be incompressible and inviscid, resulting in an irrotational flow field. The fluid domain's top free surface is assumed to be linear based on Airy’s linear wave theory. The far boundary of the fluid domain is truncated numerically close to the lock gate to control the size of computation without influencing the results, very much. It is truncated by solving the Laplace equation using Fourier half range cosine series expansion in the finite element formulation. Pressure and displacement are considered as nodal variables for the fluid domain and the lock gate, respectively. The interaction between the fluid domain and the lock gate is established by finite element formulation and transformed into a computer code, written in FORTRAN. The natural frequencies of clamped and simply supported stiffened lock gates are evaluated by the varying extent of the fluid. Both stiffened and unstiffened gates are compared. The results are beneficial to the engineers/designers when the gate structure is subjected to cataclysmic events.
Experimental Studies on Blast Performance of Unreinforced Masonry Walls: A state-of-the-art review
Authors: Anas S.M. , Alam Mehtab , Umair Mohammad
Published: December 2022

A large proportion of India’s residential buildings is of unreinforced masonry (URM) and falls under the category of non-engineered structures. URM walls in the residential buildings, customarily constructed from clay bricks or concrete blocks and cut stones, are found to be braced and therefore able to carry some out-of-plane loads produced by wind and earthquake, and survive. However, they are found to be more vulnerable to high air-pressure generated by explosive-induced detonations. Sufficient amount of investigations has been made by engineers to study the effect of brick strength, mortar strength, boundary conditions, wall thickness, and Young’s modulus of masonry on the blast performance of the URM walls. In this paper, available experimental studies on clay-brick and concrete block URM walls subjected to explosive-induced blast loading are briefly reviewed and summarized in tabular form. Studies conducted to improve the blast resistance of the walls using GFRP strips, GFRP rods, and Polyurea coating, and their effect on mid-span deflection, damage, and cracks have also been reviewed. It has been observed that the effect of brick strength and mortar strength on maximum mid-span deflection and damage resistance of the walls is insignificant under higher peak reflected blast pressures (> 2 MPa). Besides, the walls strengthened with the GFRP strips or Polyurea coating performed better with regards to mid-span deflection, damage, and cracking. The influence of Young’s modulus of masonry on the blast response of the walls is found to be more effective in reducing the maximum mid-span deflection. Also, the failure mechanism of the walls is found to be highly dependent upon the peak overpressure, duration of the blast, and support conditions.
Finite Element Analysis of Bridge Deck Using MATLAB
Authors: Farhan Ahmad , Dewangan U.K.
Published: December 2022

Bridges are the most common types of structures generally adopted when there is a obstacle in the path such as water body, valley, road etc without closing the way underneath. Moving live load is one of the critical loading for which bridge superstructure need to be analysed by developing model as realistic as possible. Even though various conventional methods are present for the analysis of bridge superstructure but finite element analysis gives us more realistic behavior of structure. The objective of the thesis is to develop a finite element model of T-beam slab bridge ,bridge pier and pier footing and analyse to study behavior of bridge superstructure for moving live load as per Indian road congress standards given in IRC:6-2017 and IRC: 112-2011 and the dead load of the structure.
In my work, bridge deck is modelled as Mindlin-Reissner plate element which is two dimensional plate in which shear deformations effect is considered whereas longitudinal girders ,cross girders and diaphragms are modelled using Euler-Bernoulli’s grid element which are a one dimensional element . A MATLAB code is developed to model T-beam slab composite action in which beam elements is modelled in plane of plate element so that the nodes of beams are coincide to the nodes of the plate by doing such center of gravity of the beam coincides with the plate element ignoring offset present between them. Moving live load analysis is performed using step by step method in which load moves in longitudinal as well as transverse direction giving the worst case for maximum bending moments, shear forces and deflections. Then Moving live load analysis for 2 lane T-beam bridge is carried out for IRC Class 70R wheeled vehicle and compare the result by modeled in sap2000,2016 of same dimension and the effect of the number of cross girders in the deck span on bending moments, shear forces and deflections of longitudinal girders is presented.
Zonal Winds of Uranus and Neptune: Gravitational Harmonics, Dynamic Self-gravity, Shape, and Rotation
Authors: Soyuer Deniz , Neuenschwander Benno , Helled Ravit
Published: December 2022

Uranus and Neptune exhibit fast surface zonal winds that can reach up to a few hundred meters per second. Previous studies on zonal gravitational harmonics and ohmic dissipation constraints suggest that the wind speeds diminish rapidly in relatively shallow depths within the planets. Through a case-by-case comparison between the missing dynamical gravitational harmonic

J

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′

from structure models, and with that expected from fluid perturbations, we put constraints on zonal wind decay in Uranus and Neptune. To this end, we generate polytropic empirical structure models of Uranus and Neptune using fourth-order theory of figures that leave hydrostatic J
4 as an open parameter. Allotting the missing dynamical contribution to density perturbations caused by zonal winds (and their dynamic self-gravity), we find that the maximum scale height of zonal winds are ∼2%–3% of the planetary radii for both planets. Allowing the models to have J
2 solutions in the ±5 × 10−6 range around the observed value has similar implications. The effect of self-gravity on

J

4

′

is roughly a factor of ten lower than that of zonal winds, as expected. The decay scale heights are virtually insensitive to the proposed modifications to the bulk rotation periods of Uranus and Neptune in the literature. Additionally, we find that the dynamical density perturbations due to zonal winds have a measurable impact on the shape of the planet, and could potentially be used to infer wind decay and bulk rotation period via future observations.
A Massive Star Is Born: How Feedback from Stellar Winds, Radiation Pressure, and Collimated Outflows Limits Accretion onto Massive Stars
Authors: Rosen Anna L.
Published: December 2022

Massive protostars attain high luminosities as they are actively accreting and the radiation pressure exerted on the gas in the star’s atmosphere may launch isotropic high-velocity winds. These winds will collide with the surrounding gas producing shock-heated (T ∼ 107 K) tenuous gas that adiabatically expands and pushes on the dense gas that may otherwise be accreted. We present a suite of 3D radiation-magnetohydrodynamic simulations of the collapse of massive prestellar cores and include radiative feedback from the stellar and dust-reprocessed radiation fields, collimated outflows, and, for the first time, isotropic stellar winds to model how these processes affect the formation of massive stars. We find that winds are initially launched when the massive protostar is still accreting and its wind properties evolve as the protostar contracts to the main sequence. Wind feedback drives asymmetric adiabatic wind bubbles that have a bipolar morphology because the dense circumstellar material pinches the expansion of the hot shock-heated gas. We term this the “wind tunnel effect.” If the core is magnetized, wind feedback is less efficient at driving adiabatic wind bubbles initially because magnetic tension delays their growth. We find that wind feedback eventually quenches accretion onto ∼30 M
⊙ protostars that form from the collapse of the isolated cores simulated here. Hence, our results suggest that ≳30 M
⊙ stars likely require larger-scale dynamical inflows from their host cloud to overcome wind feedback. Additionally, we discuss the implications of observing adiabatic wind bubbles with Chandra while the massive protostars are still highly embedded.
A New Flaring Black Widow Candidate and Demographics of Black Widow Millisecond Pulsars in the Galactic Field
Authors: Swihart Samuel J. , Strader Jay , Chomiuk Laura , Aydi Elias , Sokolovsky Kirill V. , Ray Paul S. , Kerr Matthew
Published: December 2022

We present the discovery of a new optical/X-ray source likely associated with the Fermi γ-ray source 4FGL J1408.6–2917. Its high-amplitude periodic optical variability, large spectroscopic radial-velocity semiamplitude, evidence for optical emission lines and flaring, and X-ray properties together imply the source is probably a new black widow millisecond pulsar binary. We compile the properties of the 41 confirmed and suspected field black widows, finding a median secondary mass of 0.027 ± 0.003 M
⊙. Considered jointly with the more massive redback millisecond pulsar binaries, we find that the “spider” companion mass distribution remains strongly bimodal, with essentially zero systems having companion masses of between ∼0.07 and 0.1 M
⊙. X-ray emission from black widows is typically softer and less luminous than in redbacks, consistent with less efficient particle acceleration in the intrabinary shock in black widows, excepting a few systems that appear to have more efficient “redback-like” shocks. Together black widows and redbacks dominate the census of the fastest spinning field millisecond pulsars in binaries with known companion types, making up ≳80% of systems with P
spin < 2 ms. Similar to redbacks, the neutron star masses in black widows appear on average significantly larger than the canonical 1.4 M
⊙, and many of the highest-mass neutron stars claimed to date are black widows with M
NS ≳ 2.1 M
⊙. Both of these observations are consistent with an evolutionary picture where spider millisecond pulsars emerge from short orbital period progenitors that had a lengthy period of mass transfer initiated while the companion was on the main sequence, leading to fast spins and high masses.
Deflection of O2
+ Ion Flow by Magnetic Fields in the Martian Ionosphere
Authors: Li Shibang , Lu Haoyu , Cao Jinbin , Cui Jun , Zhou Chenling , Wild James A. , Li Guokan , Li Yun
Published: December 2022

The effect of the Martian crustal magnetic field on ion escape is the focus of considerable interest. Directions of magnetic fields near Mars determined by the interaction between Mars’ crustal and interplanetary magnetic fields have been suggested to play a significant role on ion transport around Mars. In this study we investigate the physical mechanism of deflection of

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2

+

ion flow in two typical magnetic field orientations at the horizontal plane in the Martian ionosphere by performing 3D multifluid Hall magnetohydrodynamic simulations. Cross validation of the simulation results from two cases with the G110 crustal field model and equivalent source dipole model reveals that due to the Hall electric force,

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ion flow tends to be accelerated eastwards in the region occupied by outward magnetic fields, and westwards in the region with inward magnetic fields. These results are helpful for understanding the impact of magnetic fields on the deflection of ionospheric ions in the Martian space environment.
Quantum Chemical Computations of Gas-phase Glycolaldehyde Deuteration and Constraints on Its Formation Route
Authors: Vazart Fanny , Ceccarelli Cecilia , Balucani Nadia , Skouteris Dimitrios
Published: December 2022

Despite the detection of numerous interstellar complex organic molecules (iCOMs) for decades, it is still a matter of debate whether they are synthesized in the gas phase or on the icy surface of interstellar grains. In the past, molecular deuteration has been used to constrain the formation paths of small and abundant hydrogenated interstellar species. More recently, the deuteration degree of formamide, one of the most interesting iCOMs, has also been explained with the hypothesis that it is formed by the gas-phase reaction NH2 + H2CO. In this paper, we aim at using molecular deuteration to constrain the formation of another iCOM, glycolaldehyde, which is an important prebiotic species. More specifically, we have performed dedicated electronic structure and kinetic calculations to establish the glycolaldehyde deuteration degree in relation to that of ethanol, which is its possible parent species according to the suggestion of Skouteris et al. We found that the abundance ratio of the species containing one D atom over the all-protium counterpart depends on the produced D isotopomer and varies from 0.9 to 0.5. These theoretical predictions compare extremely well with the monodeuterated isotopomers of glycolaldehyde and that of ethanol measured toward the solar-like protostar IRAS 16293–2422, supporting the hypothesis that glycolaldehyde could be produced in the gas phase for this source. In addition, the present work confirms that the deuterium fractionation of iCOMs cannot be simply anticipated based on the deuterium fractionation of the parent species but necessitates a specific study, as already shown for the case of formamide.
Detection of the Extended γ-Ray Emission from the High Galactic Latitude Calvera’s SNR Candidate
Authors: Xin Yuliang , Guo Xiaolei
Published: December 2022

We report the extended GeV γ-ray emission that is spatially associated with the high Galactic latitude supernova remnant (SNR) candidate—Calvera’s SNR with the Pass 8 data recorded by the Fermi Large Area Telescope. The γ-ray spectrum of Calvera’s SNR between 100 MeV and 1 TeV shows an evident (∼3.4σ) spectral curvature at several tens of GeV. The multiwavelength data can be fitted with either a leptonic model or a hadronic one. However, the leptonic model exhibits inconsistency between the flat radio spectrum and the hard GeV γ-ray spectrum of Calvera’s SNR. For the hadronic model, the spectral index of protons should be harder than 1.6 and the total energy of protons is fitted to be more than one order of magnitude higher than the explosion energy of a typical supernova, which also challenges the hadronic model. The evident spectral curvature and the absence of nonthermal X-ray emission from Calvera’s SNR makes it to be an interesting source bridging young-aged SNRs with bright nonthermal X-ray emission and old-aged SNRs interacting with molecular clouds.
Observed Rate Variations in Superflaring G-type Stars
Authors: Crowley James , Wheatland Michael S. , Yang Kai
Published: December 2022

Flare occurrence on the Sun is highly variable, exhibiting both short-term variation due to the emergence and evolution of active regions, and long-term variation from the solar cycle. On solar-like stars, more energetic stellar flares (superflares) have been observed, and it is of interest to determine whether the observed rates of superflare occurrence exhibit similar variability to solar flares. We analyze 274 G-type stars using data from the Transiting Exoplanet Survey Satellite and identify seven stars which exhibit statistically significant changes in the rate of superflare occurrence by fitting a piecewise constant-rate model with the Bayesian blocks algorithm. We investigate the properties of these stars and their flaring rates, and discuss the possible reasons for the low number of stars with detectable rate variation.
RELICS: A Strong-lens Model of SMACS J0723.3-7327*
Authors: Sharon Keren , Chen Mandy C. , Mahler Guillaume , Coe Dan ,   (RELICS: Reionization Lensing Cluster Survey)
Published: December 2022

We present the details of a strong-lens model of SMACS J0723.3-7327, which was made public as part of the data and high-level science products (HLSP) release of the RELICS Hubble Space Telescope (HST) treasury program (Reionization Lensing Cluster Survey; GO-14096, PI: Coe). The model products were made available on the Mikulski Archive for Space Telescopes via 10.17909/T9SP45 in 2017. Here, we provide the list of constraints that were used in the HST-based RELICS lens model, as well as other information related to our modeling choices, which were not published with the data and HLSP release. This model was computed with Lenstool, used a total of 25 multiple images of eight sources, with no spectroscopic redshifts. The image-plane rms was 0.″58.
Antibacterial Activity of Gallic Acid from the Leaves of Altingia excelsa Noronha to Enterococcus faecalis
Authors: Anwar Risyandi , Hajardhini Puspita
Published: December 2022

AIM : The aim of this study was to determine the antibacterial compound of Altingia excelsa leaves to inhibit the growth of Entrococcus faecalis.
METHODS : The study was true experimental laboratory design. Separating the ethyl acetate extract via their compounds using various chromatographic techniques. Four extracts from A. excelsa leaves was obtained by the maceration method. The highest inhibitory effect was then continued to be isolated until one compound was obtained. Therefore, additional assay to determine chemical structure of compounds was done using UV spectra, infrared (IR), core magnetic resonance (NMR), and comparison with spectra data from the literature. The data were analyzed by ANACOVA assay.
RESULTS : The highest inhibitory effect was the ethyl acetate extract. The chemical structure of compound 1 was identified as an acidic compound 3,4,5 -trihydroxy benzoate, namely as the gallic acid which had inhibitory effect against Enterococcus faecalis. Antibacterial test against Enterococcus faecalis was done to determine inhibitory effect by its compound and MIC values showed of 12.25 µg/mL.
CONCLUSION : Gallic acid as the compound of Altingia excelsa leaves had a strong inhibitory effect to Enterococcus faecalis.
Effect of Secretome-Hypoxia Mesenchymal Stem Cells on Regulating SOD and MMP-1 mRNA Expressions in Skin Hyperpigmentation Rats
Authors: Zukhiroh Zukhiroh , Putra Agung , Chodidjah Chodidjah , Sumarawati Titiek , Subchan Prasetyowati , Trisnadi Setyo , Hidayah Nurul , Amalina Nur Dina
Published: December 2022

BACKGROUND: Ultraviolet B (UVB) radiation is the main factor causing hyperpigmentation. MSC secretome contains bioactive soluble molecules such as cytokines and growth factors that can accelerate skin regeneration. However, the molecular role of the secretome in hyperpigmentation is still unclear. AIM: This study aimed to determine the effect of secretome hypoxia mesenchymal stem cells (S-HMSC) gel on the expression of superoxide dismutase (SOD) and matrix metalloproteinases (MMP-1) genes in skin tissue of hyperpigmented rats induced by UVB light exposure. MATERIALS AND METHODS: Experimental research with post-test only control group. The control, base gel, T1 and T2 groups were UVB irradiated 6 times in 14 days at 302 nm with an minimal erythema dose of 390 mJ/cm2, respectively, while sham group did not receive UVB exposure. T1 was given 100 uL of S-HMSC gel and T2 was given 200 uL of S-HMSC gel every day for 14 days, while base gel received base gel. On day 15, skin tissue was isolated and analyzed for SOD and MMP-1 expression using qRT-PCR. RESULTS: The relative expression of the SOD gene in the treatment group (P1 = 0.47 ± 0.20, P2 = 1.22 ± 0.47) increased with increasing dose compared to the control group (UVB = 0.05 ± 0.01, Base gel = 0.05 ± 0.02). The relative expression of the MMP-1 gene in the treatment group (T1 = 5.82 ± 1.16, T2 = 2.86 ± 1.57) decreased with increasing dose compared to the control group (Control = 10.10 ± 2.31, and Base gel = 9.55 ± 1.29). CONCLUSION: Administration of S-HMSC gel can increase SOD gene expression and decrease MMP-1 gene expression in skin tissue of hyperpigmented rats model induced by UVB light.
The Relationship Between Environmental Taxes, Technological Innovation and Corporate Financial Performance: a Heterogeneous Analysis of Micro-Evidence from China
Authors: Xiaowei Ding , Petrovskaya Maria
Published: December 2022

As a formal environmental regulation, environmental tax is important for the green upgrading of industrial structure. In order to explore the impact mechanism of environmental tax on corporate financial performance, this paper constructs a difference-difference (DID) model with two-way fixed effects based on financial data of Chinese A-share manufacturing listed companies from 2015 to 2019. We have found that environmental taxes contribute directly and significantly to the improvement of financial performance and that technological innovation, in some degree, produces mediating effect. Financing constraints not only negatively moderate the relationship between environmental taxes and technological innovation; they also inhibit the impact of technological innovation on financial performance and have a moderate mediating effect as part of the indirect influence. In the heterogeneity analysis, the direct effect is more significant among State-owned enterprises (SOEs) and eastern enterprises, and the moderating effect of financing constraints is more significant among non-SOEs and eastern enterprises. This paper advances the understanding of economic consequences of environmental tax levies from the perspective of property and regional heterogeneity. It provides empirical evidence in support of the applicability of Porter’s hypothesis in China and makes suggestions for the optimization of environmental policy and improvement of financial performance of enterprises.