Shear Values Research Articles

Shear wave elastography values of thrombus in patients with lower extremity deep vein thrombosis for pulmonary embolism detection: the ROC analysis

Rationale: Thrombosis of the iliac (IV) and femoral veins (FV) is one of the most common causes of pulmonary embolism (PE). Modern ultrasound scanners are equipped with the technology of shear wave elastography, which gives a quantitative assessment of thrombus stiffness by Young's modulus reconstruction. However, the lack of convincing data on the role of thrombus stiffness for clinical manifestations of PE hinders the active use of shear wave elastography to diagnose the risk of embolism.
 Aim: To determine the threshold values of the venous thrombus Young’s modulus for deep venous thrombosis (DVT) of the lower extremities complicated by massive PE and/or PE with acute cor pulmonale (ACP).
 Materials and methods: This was a single center cross-sectional study in 101 patients who were hospitalized with the diagnosis of acute (duration of less than 2 weeks) or subacute (from 2 weeks to 3 months) IV and FV thrombosis. Doppler ultrasound of the lower extremity veins and echocardiography were done in all patients. Forty eight patients with clinical signs of PE had chest computed tomography. The venous thrombus stiffness was assessed by shear wave elastography with the Young's modulus reconstruction. We performed the ROC analysis for mean values of the Young's modulus for proximal segments of IV and FV thrombi in patients with DVT and massive PE and ACP.
 Results: PE was diagnosed in 40.6% (26/64) of the patients hospitalized with acute DVT and in 54.1% (20/37) of those with subacute DVT. Echocardiographic signs of ACP in massive PE were found in 47.4% (9/19) of the patients, in submassive and minor PE in 55.6% (15/27). In DVT complicated with PE, the ROC analysis of the shear wave elastography results gave the following threshold values of the mean Young’s modulus for the proximal thrombus segment: for acute IV thrombosis + PE and ACP, ≤ 16.7 kPa (AUC 0.714, sensitivity 100%, specificity 42.1%), in subacute IV thrombosis + PE and APC, ≤ 23.7 kPa (0.939, 100 and 90.9%, respectively), in acute FV thrombosis + massive PE, ≥ 9.5 kPa (0.706, 100 and 50%, respectively), in subacute FV thrombosis + massive PE, ≥ 24.4 kPa (0.550, 60.0 and 68.8%, respectively).
 Conclusion: Shear wave elastography of deep vein thrombi of the lower extremities makes it possible to identify patients with PE and ACP during acute and subacute IV thrombosis and to determine massive PE in acute FV thrombosis.

Estimating Max moment and shear exerted on contiguous piles subjected to earthquake using ANN.

Recently the usage of Contiguous piles in many different aspects of construction projects are become more common. Determination of the shear force and moment values exerted on the contiguous piles require extensive analysis and calculations especially when earthquake is to be encountered. ANN mathematical models for calculating this value combining 144 input sets that represent height of excavated (H), ratio of H to the depth of embedment (D), unit weight of retained soil ( ) and angle of internal friction ( ) is presented in this paper. The mathematical models obtained show acceptable regression and deviation. It was found that both shear and moment values subjected on the piles are decreases with the decrease of ( ) and increases with the increase of ( ). The height of excavation (H) was found as the most important input parameter that affects the output values of the models

Predicting the magnitude of technogenic earthquakes during underground mining of the Zhezkazgan ore field

Purpose. Determining a relationship between the shear/failure of the rock mass and the technogenic earthquakes caused by them during underground mining of ore deposits with the derivation of an equation for the dependence of the technogenic earthquake indicators for the conditions of the Zhezkazgan copper-ore field. Methods. The research methodology consists of studying and analyzing early research on technogenic earthquakes by the method of statistical data processing. Calculation of rock mass deformation distribution in the study area is based on numerical modeling in the Comsol Multiphysics 5.6 and MATLAB 2020 software package environment. Calculations are performed based on solving a plane problem using the Finite Element Method (FEM). Findings. Based on the transition from the failure area to subsidence and shear values of the overlying rock mass stratum, an equation for the dependence of the earthquake magnitude on the numerical values of the mass subsidence or shear has been obtained. Originality. For the first time, based on the physics and geomechanics of rock mass shear processes, empirical-analytical formulas have been obtained that make it possible to predict the technogenic earthquake magnitude during underground mining of ore deposits in the conditions of the Zhezkazgan copper-ore field. Practical implications. Preliminary predictive calculations made by the obtained formulas for the conditions of the active mine No. 31 of the East-Zhezkazgan mine, ТОО Kazakhmys Smelting, show acceptable results of magnitude value, comparable to in-situ measurements during field mining. This prediction makes it possible to pre-calculate the technogenic earthquake magnitude at the stage of designing mining operations and make appropriate scientifically sound decisions during further mining of the field.

Rheological Study on Blend Solutions of Non-mulberry Silk Fibroin and Gelatin Biopolymers

In current research work, we have studied the blending effect of non-mulberry silk fibroin (10% weight/volume basis) and gelatin (20% weight/volume basis) in formic acid. Several blends as SF10G0, SF2G8, SF3G7, SF5G5 and SF0G10 have been made and their rheological behaviour was investigated. The blend solutions were subjected to a steady shear rheological study in the variety of range of shear rates, namely 0.01–500 sec-1 and the viscosities of blend solutions were noticed to decrease in comparison to pure silk solution. The frequency sweep was employed in dynamic rheological tests to determine complex viscosity of these solutions from range of angular sweep 0.1–100 rad/sec. The consistent shear-thinning behaviour was noted for all the blends. The difference in numerical values of shear and complex viscosities indicated disobedience of Cox-Merz rule. Such analysis can be utilised for tailoring the properties of solution prior to processing them to create a versatile range of materials.

Comparative Analysis of Shear Strength Prediction Models for Reinforced Concrete Slab–Column Connections

This research focuses on a comprehensive comparative analysis of shear strength prediction in slab–column connections, integrating machine learning, design codes, and finite element analysis (FEA). The existing empirical models lack the influencing parameters that decrease their prediction accuracy. In this paper, current design codes of American Concrete Institute 318-19 (ACI 318-19) and Eurocode 2 (EC2), as well as innovative approaches like the compressive force path method and machine learning models are employed to predict the punching shear strength using a comprehensive database of 610 samples. The database consists of seven key parameters including slab depth (ds), column dimension (cs), shear span ratio (av/d), yield strength of longitudinal steel (fy), longitudinal reinforcement ratio (ρl), ultimate load-carrying capacity (Vu), and concrete compressive strength (fc). Compared with the design codes and other machine learning models, the particle swarm optimization-based feedforward neural network (PSOFNN) performed the best predictions. PSOFNN predicted the punching shear of flat slab with maximum accuracy with R2 value of 99.37% and least MSE and MAE values of 0.0275% and 1.214%, respectively. The findings of the study are validated through FEA of slabs to confirm experimental results and machine learning predictions that showed excellent agreement with PSOFNN predictions. The research also provides insight into the application of metaheuristic models along with ANN, revealing that not all metaheuristic models can outperform ANN as usually perceived. The study also highlights superior predictive capabilities of EC2 over ACI 318-19 for punching shear values.

Enhancing Structural Resilience: A Comparative Study of G+35 Storey Irregular Buildings with Bracing and Diagrid Systems

Abstract: The study presented herein delves into the structural performance and behavior of a building subjected to different configurations, namely, an Irregular Building, an Irregular Building with Steel Bracing, and an Irregular Building with Diagrid System. The focus of the investigation is on key structural parameters such as node displacements and storey shear values across various levels of the building. Understanding how these parameters vary in response to different design strategies is vital for assessing the overall stability, safety, and efficiency of the structure in the face of external forces. Structural engineers and designers are constantly striving to optimize building designs to meet safety standards and performance criteria. The incorporation of additional elements, such as steel bracing or a diagrid system, can significantly impact a structure's ability to withstand lateral forces, ensuring resilience in the face of dynamic loads such as wind or seismic events. By comparing the performance of the three configurations, this study aims to provide insights into the efficacy of these design strategies and their influence on key structural indicators. Through a comprehensive analysis of node displacements and storey shear values at various levels, this study seeks to contribute valuable information to the field of structural engineering. The findings may inform future design decisions, guide improvements in structural systems, and enhance the understanding of how different configurations influence the overall behavior of a building. Ultimately, the knowledge gained from this study can contribute to the advancement of resilient and efficient structural designs, with implications for the broader fields of architecture and civil engineering.

Seismic Response of Stiffness Irregularity at Ground Floor with and without Shear Walls

In today's scenario, one of the greatest challenges for structural engineers is designing and constructing seismic-resistant structures. Seismic activity, or earthquakes, poses a significant threat to civil engineering structures, and ensuring that buildings can withstand the forces generated during an earthquake is crucial for public safety and infrastructure resilience. Irregular configurations, whether in the building's floor plan or its elevation, are widely acknowledged as significant contributors to failure during seismic events. These irregularities can lead to uneven distribution of forces and stresses, compromising the building's ability to withstand the seismic forces and potentially resulting in structural failure. Soft storeys, typically located at ground levels for various functional purposes, pose challenges in seismic regions due to their lack of sufficient lateral load-resisting elements resulting in excessive lateral deformation and collapse during intensive earthquakes. Hence, the present study investigated the seismic response of irregular reinforced concrete structures possessing stiffness irregularity at ground floor with and without shear walls. A ten-storey regular frame is modified by incorporating vertical irregularity in elevation by increasing the height of the ground floor. The complete structural analysis and modeling are carried out by using the software ETABS 2020. The Time History method is applied, and the study is focused on seismic zones V in India. The performance of structures are compared based on criteria such as storey displacement, storey drift, storey shear and overturning moment. The results lead to the conclusion that a building structure exhibiting stiffness irregularity is prone to instability which is indicated by higher displacement and drift values. Structures incorporating shear walls have demonstrated greater stability compared to structures without shear wall as they exhibited higher base shear values and experienced a reduction in lateral displacement by more than 40%. The presence of shear walls also has enhanced the stability and strength of the structure, showing a linear response during critical earthquakes.

A New Optimization Approach for the Tallest Column Design

Motivated by the classical brachistochrone we present a new pattern of finding the shape of a vertical column that attains the maximum height if its material and volume are prescribed. It comprises the optimal control problem with a free end point. Besides, the constitutive equation of the column is such that it can suffer flexure, compression and shear. The critical load of a heavy compressed column for the finite values of shear and extensional rigidity and the novel use of the Pontryagin maximum principle with the corresponding first integral yielding the non-vanishing optimal cross section as a solution of a quadratic equation are main novelties of this work. The classical solution for the tallest column under selfweight is covered as a special case for infinite values of shear and extensional rigidity.

Seismic Evaluation of Retrofitting Technique Using Bracing Systems for Steel Multi-Story Building

A bracing system is the one of effective retrofitting methods for existing high buildings to support the lateral loads. Structural bracings increase the stiffness and stability of the building and the energy dissipation capacity. In this research, the numerical study of retrofitting a multi-story steel building near Imam Ali Holy Shrine in Najaf, Iraq has been conducted. The retrofitting mechanism includes a test of four different bracing systems such as X-bracing, V-bracing, Diagonal-bracing and IV-bracing located in the x and y-axis of the model. The seismic analysis using the elastic response spectrum method was performed for two types of earthquakes, weak and strong. The comparison among different parameters is discussed such as maximum lateral displacement, story drift ratio and base shear values. The seismic load was applied in two axes of the building model simultaneously and the results of the parameters in the x and y-axis were extracted. The results show that the retrofitting using four bracing system types increases the capacity of energy dissipation of the existing building model to seismic load by reducing the maximum lateral displacement in the x-axis by 55%, 44%, 41%, and 30% for X, IV, V and Diagonal-bracing, respectively. However, the X-bracing has a significant increase of the shear base value of the model by 39% and 49% in the x and y-axis, respectively, which means cost-effective compared with the other bracing types. Therefore, the IV-bracing type has an appropriate effect on the strength of the building against seismic load with reasonable cost-effectiveness.

Physico-Chemical and Sensory Assessment of Local and Imported Catfish Fillets

In this study, twenty fresh African catfish (Clarias gariepinus) and silver catfish (Bagrus bayad) fillets as well as twenty frozen pangasius catfish (Pangasianodon hypophthalmus) fillets were collected from Egyptian local markets and retailers during 2021. Pangasius catfish fillets can be divided into two grades: white basa fillets (grade I, white colour) and red basa fillets (grade II, pale pink to red colour). This study aimed to assess the physical (colour and shear force), chemical (pH, TVB-N and TBARS) and sensory parameters of catfish fillet samples. The sensory attributes of raw catfish fillets were measured using a 9-point hedonic scale and these attributes include colour and appearance, odor, texture, and overall acceptability. The results of the proximate composition showed that the African catfish and silver catfish fillets had significantly lower moisture (76.12-76.94) and higher crude protein (17.19-17.24) and fat levels (3.35-4.12) compared to the frozen Pangasius catfish fillets. The total volatile basic nitrogen (TVB-N) ranged from 6.83 to 16.38 mg/100g, thiobarbituric acid-reactive substances (TBARS) values ranged from 0.35 to 1.01 mg malonaldehyde/kg and pH ranged from 6.43 to 7.35. The TVB-N and TBARS values of examined catfish fillets were within acceptable limits. The African catfish fillets were darker and characterized by higher redness (a*) and lower yellowness (b*) values as well as higher shear force values (9.52 kgf/m3), while white basa fillet was the lowest darkness, less saturated with the red pigment (a*) and more saturated with the yellow component (b*) as well as lower shear values (2.17 kgf/m3) among the examined catfish fillets. African catfish and silver catfish fillets showed significantly higher sensory scores than the Pangasius catfish fillets. All the organoleptic properties of raw catfish fillets were above the rejection threshold score (≤4.0) In conclusion, catfish fillets were of superior quality and acceptable for human consumption.

DEFLECTION OF FLAT SLAB-DROP PANEL IN THE G2 BUILDING AT WARMADEWA UNIVERSITY

To conserve building height, flat slabs are concrete structures that do not employ beams as weight transfer to columns. The flat slab system structure is prone to shear collapse due to the lack of beams. A column head is made to forward the load from the plate to the column so that the shear value in the building is not too high. This is done by expansion at the end of the column or by thickening around the critical circumference of the column and plate meeting. The Warmadewa University G2 Building Planning Analysis is carried out during the planning stage, using a flat slab-drop panel structural system as one of the optional structural systems that can be used to obtain a building height that is in accordance with Bali Provincial Regulation Number 16 of 2009 concerning the regional spatial plan of the Province of Bali. Terompong street No. 24, Sumerta Kelod, East Denpasar sub-district, Denpasar City, Bali, is where the Warmadewa University G2 building will be built. According to the soil data, the building is constructed on a medium soil site class with a building structure risk level IV. The Warmadewa University G2 Building structure was studied using etabs v.18 software in accordance with SNI 2847-2019 requirements for structural concrete for building buildings and loading in accordance with SNI 1727-2020 criteria. The biggest deflection value occurs in the middle lane due to the load from the function room, as determined by the study for the dimensions of the 350mm thick drop panel and 250mm thick slab utilizing a column size of 600 x 600 mm with a span of 8000mm. The inner drop panel experiences the highest lateral loads due to shear failure.

Development of Topical Formulations Containing 20% of Coated and Uncoated Zinc Oxide Nanoparticles: Stability Assessment and Penetration Evaluation by Reflectance Confocal Laser Microscopy

The introduction of zinc oxide nanoparticles (ZnOn) in sunscreens solved the issue of poor spreadability of these formulations, which often left a white film on the skin. However, safety concerns have arisen regarding the topical application of ZnOn. Some studies employed commercial sunscreens to address the safety issues of the topical application of ZnOn; however, commercial formulations are often complex and contain a wide range of ingredients that could attenuate the potential damage caused by the ZnOn. Therefore, in this study we aimed to develop a simple stable formulation containing 20% of coated and uncoated ZnOn, characterize the formulations and the nanoparticles, and assess the skin penetration in a Franz diffusion cell. The Feret’s diameter for the uncoated and coated ZnOn was 137 nm and 134 nm, respectively. For the uncoated ZnOn the hydrodynamic size in water was 368 nm and for the coated ZnOn, the average hydrodynamic size in ethyl acetate was 135 nm. The incorporation of ZnOn led to formulations more consistent and easier to spread, as suggested by the lower work of shear and higher values of firmness, cohesiveness, consistency and index of viscosity compared with the vehicle. The stability assessment at 45 °C suggested that the formulations containing the ZnOn were stable for 30 days and the vehicle was stable for 90 days. The assessment of the skin penetration by reflectance confocal laser microscopy indicated that the ZnOn did not permeate into the deepest layers of the skin, but accumulated on the skin furrows, hair and hair follicles.

ЭФФЕКТИВНОСТЬ КВАДРАТНОГО АРМИРОВАННОГО ВОЛОКНОМ ЭЛАСТОМЕРНОГО ИЗОЛЯТОРА ДЛЯ ЖЕЛЕЗОБЕТОННОГО ЗДАНИЯ ПРИ ЗЕМЛЯТРЕСЕНИЯХ

Un-bonded fiber reinforced elastomeric isolator (U-FREI) is a relatively new type of multi-layer elastomeric isolator in which fiber layers are used as reinforcement to replace steel sheets in conventional steel reinforced elastomeric isolators. It is installed directly between the substructure and superstructure without any connection at the interfaces. Most of the previous studies on the U-FREIs supported to the base-isolated buildings are masonry or stone structures. In this study, the dynamic responses of a reinforced concrete (RC) building supported on square U-FREIs under the action of recorded real time-history ground motions of earthquakes are investigated by finite element analysis using SAP2000 software. A hypothetical 4-storey reinforced concrete building constructed in Vietnam is selected for the study. Comparison of the dynamic responses of the base-isolated building and corresponding fixed-base building is carried out to evaluate the seismic vulnerability of the base-isolated building under earthquakes. Finite element analysis results show that peak values of floor acceleration and inter-storey drifts at different floor levels, and peak value of base shear of the base-isolated building are lower than those of the corresponding fixed-base building. The U-FREIs are found to be very effective in reducing seismic vulnerability of low and mid-rise RC buildings.

Direct cohesive law measurement under mixed-mode loading using semi-circular bend (SCB) specimens

The present paper suggests a new method to obtain pure mode and mixed mode traction-separation laws of adhesives using semi-circular bend (SCB) specimen by employing the digital image correlation (DIC) technique. This specimen was recently proposed by the same authors for fracture energy assessment of adhesives. This test method doesn't require any special apparatus or loading jig for mixed mode fracture tests ranging from pure mode I to pure mode II. Lower cost and higher precision than conventional methods are the most advantages of using SCB fracture tests. The primary drawback of this test method lies in its data reduction process. To address this limitation, this paper introduces a direct approach for measuring fracture energy and cohesive law parameters of the adhesive. In this method, substrate strains at the interface are used to calculate the cohesive stress applied to the adhesive layer at each desired section. Shear and normal separation values are obtained directly from DIC displacement results. The proposed method was applied to the SCB specimen subjected to pure modes I and II and for mixed-mode I/II cohesive laws. Four different SCB specimens were manufactured and tested to cover different mode mixities between pure mode I and pure mode II. The experimentally obtained cohesive laws were evaluated using finite element analysis (FEA). Good agreement between the experimental and numerical results were observed.

Modulation of tropical cyclone rapid intensification by mesoscale asymmetries

AbstractComputer model simulations are one of the most important tools in current use for understanding tropical cyclone (TC) formation and rapid intensification (RI). These include “idealized” simulations in which a TC‐like vortex is placed in a hypothetical environment with predefined sea surface temperature and vertical profiles of temperature, humidity, and wind that are either constant or slowly varying across a large domain. The vast majority of such simulations begin with a perfectly circular vortex as the precursor to a TC. However, most real TCs form or intensify while interacting with asymmetric wind fields either within or external to the vortex circulation. This study introduces a method to initialize idealized TC simulations with asymmetries, and investigates the extent to which such asymmetries might delay RI in favorable environments. It is shown that mesoscale asymmetries can delay RI and reduce the fastest rates of intensification, and that these effects are statistically significantly increased when relatively low values of vertical shear of the horizontal wind are present. In some cases the asymmetries tilt the vortex directly through advection. In other cases, the wind asymmetries increase the disorganization of the convection or increase the size of the inner‐core wind field, and thus make the weaker TC more susceptible to environmental wind shear. The results suggest that mesoscale asymmetries of the wind field could be useful predictors for delay of RI in otherwise favorable environments.

Analysis of Sumatran Earthquake Coulomb Stress Changes in Geothermal Potential in Rianite, Samosir Regency

Increasing energy demand and high world oil prices are making countries turn to geothermal energy use. Indonesia is a country that has geothermal energy due to Indonesia's geographical location and geological conditions, which is located between three active earth plates so that Indonesia has 240 volcanoes and often experiences earthquakes. The 2003-2013 earthquake data obtained are coordinates, magnitude, depth, focal mechanism and all these data are analyzed in the coulomb stress method. Rianiate geothermal measurement data in March 2013 included geothermal location, hotspring and air temperature, pH, and geochemical measurements. The analysis results showed that the highest coulomb stress value was at a depth of 90 km of 0.56 bar while the shear and normal values were 0.452 bar and 0.251 bar. The result of the spread of coulomb stress is to the northeast, east and southeast. Then the results of the analysis of the direction of distribution of coulomb stress are compared to the location of the hotspring based on a decrease in temperature, the change in the potential of hotspring 1 leads to hotspring 2, 3, and 4 in the opposite direction, namely northwest or leads to the largest source of colulomb stress, so that Coulomb Stress Changes affect indirectly changes in the geothermal potential of Rianiate

Analysis and Application of Double Steel Plate Concrete Composite Shear Wall in the R&D Building of Zhanjiang Bay Laboratory

The R&D Building of Zhanjiang Bay Laboratory is a high-rise structure with multiple irregular items exceeding the specification limit, employing a steel frame-shear wall structural system. The outer frame consists of square steel tube concrete columns and solid-web steel beams, while the core shear wall uses a double steel plate concrete composite shear wall. This paper employs the architectural structural calculation software YJK-EP to perform a dynamic elastic-plastic time-history analysis under rare earthquake action. The shear and bending resistance of the shear wall at the maximum shear force and bending moment are checked to meet the requirements of the “Technical Specifications for Concrete Structures of High-rise Buildings”. The maximum inter-story displacement angle meets the requirements of the “Code for Seismic Design of Buildings”. The double steel plate concrete composite shear wall Wall-1, connected to a large-span and heavy-load transfer truss, was verified under significant seismic action using the ABAQUS software. The results indicate that Wall-1 can meet the design target requirements under major earthquake conditions. Finally, a dynamic nonlinear analysis method was employed using MIDAS-GEN software to study the structure’s anti-progressive collapse performance. The results show that under seven different scenarios, the maximum rotational angle of the remaining structural horizontal members is 2.02°, far less than the limit set by GSA, indicating that a progressive collapse did not occur. In the scenario where the corner column is removed, both the maximum shear and bending moment values for Wall-1 are far below its shear and bending resistance capacities, satisfying the load-bearing requirements. The removal of the corner column has a significant impact on the displacement of the columns on the same level nearby, with the peak displacement change rate reaching 702.65%.

On the Distribution of Convective and Stratiform Precipitation in Tropical Cyclones from Airborne Doppler Radar and Its Relationship to Intensity Change and Environmental Wind Shear Direction

Abstract Airborne Doppler radar reflectivity data collected in hurricanes on the NOAA P-3 aircraft between 1997 and 2021 were parsed into different modes of precipitation: stratiform precipitation, shallow convection, moderate convection, and deep convection. Stratiform precipitation was the most frequent precipitation mode with 82.6% of all observed precipitation while deep convection was the most infrequent at 1.3%. When stratified by 12-h intensity change, intensifying TCs had a greater areal coverage of total convection in the eyewall compared to weakening and steady-state TCs. The largest difference in the azimuthal distributions in the precipitation modes was in deep convection, which was mostly confined to the downshear-left quadrant in weakening and steady-state hurricanes and more symmetrically distributed in intensifying hurricanes. For all intensity change categories, the most symmetrically distributed precipitation mode was stratiform rain. To build upon the results of a recent thermodynamic study, the precipitation data were recategorized for hurricanes experiencing deep-layer wind shear with either a northerly component or southerly component. Like intensifying storms, hurricanes that experienced northerly component shear had a more symmetric distribution of deep convection than southerly component shear storms, which had a distribution of deep convection that resembled weakening storms. The greatest difference in the precipitation distributions between the shear direction groups were in major hurricanes experiencing moderate (4.5–11 m s−1) wind shear values. Consistent with previous airborne radar studies, the results suggest that considering the distribution of deep convection and the thermodynamic distributions associated with differing environmental wind shear direction could aid TC intensity forecasts. Significance Statement This research investigates how the distribution of different types of precipitation are related to tropical cyclone (TC) intensity change. Even though deep convection—the tallest clouds—is the least frequent type of precipitation, it has the strongest relationship to intensity change with uniform distributions around the eyewall associated with intensification. Less significant relationships were noticed for shallower clouds and stratiform (lighter) rain. The study also analyzed how change in direction of the large-scale winds with height (wind shear) influences intensity change. When wind shear is northerly, there is a more symmetric distribution of deep convection compared to when wind shear is southerly. These relationships illustrate how wind shear direction influences TC convective structure and, in turn, TC intensity change.

Seismic studies on energy dissipation device performance for irregular steel structure in different soil conditions using ETABS

Earthquakes are sudden loads that occur and cause low to severe damage to the structure. Based on the intensity of an earthquake, the zones are divided into II, III, IV and V as per IS code 1893:2016(Part-1). Regular, Stiffness Irregular and Mass Irregular G+7 steel building is designed for four zones in ETABS software. Linear Static and Linear Dynamic analyses are performed on all zones for different conditions of soils. In this work, a steel G+7 storeyed structure is developed in ETABS and subjected to seismic loading. For Energy dissipation, the dampers are installed in the building and the analysis process is done. In this research, seismic study is carried out on various models using energy dissipation devices such as fluid viscous damper. The different irregularities in a building in four zones are analyzed with and without using dampers. The study is concluded by comparing displacement and storey shear values for different models.

Severe convective outbreak in Siberia in May 2020: Event analysis and high-resolution simulation

Western Siberia is exposed to extreme wind events caused by severe convective storms. However, our knowledge on such storms in Siberia is still fragmentary compared to other parts of the world primarily due to the lack of weather radar data. These storms cause substantial damage, which signifies the need for comprehensive assessment of their characteristics and predictability even on the basis of existing data. In this paper, we present a case study analysis of a severe weather outbreak that occurred on 25–26 May 2020 in Western Siberia, during a record six-month heatwave that lasted in Siberia from January to June. The outbreak resulted in six fatalities and substantial economic losses. Using various satellite data and damage reports we found that two consecutive mesoscale convective systems (MCSs) developed within the outbreak having an exceptionally long total track about 2000 km and causing large-scale forest damage with a total area of 64.5 km2. Such an exceptionally long path was supported by a strong mid-tropospheric jet, which settled extremely high values of wind shear that fostered the development of the outbreak. To analyze the accuracy of the forecast of the MCS and three associated windstorms on 26 May, we performed a set of simulations with the COSMO and ICON numerical weather prediction models launched with convection-permitting resolution (2.2 km) with different forecast lead times. Both models successfully predicted the most severe windstorm with the <50 km spatial displacement and the <1.5 h time shift, but COSMO generally simulated more strong wind. However, two other windstorms of that day were predicted with lower accuracy. The simulation results revealed a limited sensitivity of the model to variations in initial soil temperature and moisture. Together with the better performance of the forecast with >24 h lead time, this emphasized the predominant role of large-scale dynamics and the minor role of local factors in the outbreak formation and development. In particular, the intrusion of the upper tropospheric high potential vorticity streamer along the blocking periphery induced strong deep convection and determined the severe character of the outbreak. Specifically, the studied outbreak had an exceptional longevity compared to other long-lived windstorms observed in Northern Eurasia at the blocking periphery.