Analysis Of Parameters Research Articles

Effects of Steviol Glycosides on Growth Performance, Ruminal Fermentation and Microbial Diversity of Hu Sheep.

The experiment was conducted to investigate the potential effects of steviol glycosides on growth performance, rumen fermentation processes, and microbial diversity in Hu sheep. A single-factor design was used for the trial. Twenty healthy weaned Hu lambs, possessing comparable body weights averaging 18.31 ± 1.24 kg, were randomly allocated into two distinct groups: the control group (CON) and the experimental group (STE), with each comprising 10 lambs. The CON was fed the basal diet, and the STE was supplemented with 0.07% steviol glycosides based on the basal diet. During the experimental period, variations in body weight and feed intake were closely monitored and recorded. After feeding for 90 d, blood was collected to determine blood biochemical indices, and rumen fluid samples were gathered for an in-depth analysis of rumen fermentation parameters and microbial diversity. The outcomes revealed no statistically significant differences in growth performance or serum biochemical indices between the two groups (p > 0.05). Rumen pH in STE and CON was within the normal range. The rumen ammonia nitrogen (NH3-N) and acetic acid (AA) content of STE decreased significantly compared with CON (p < 0.05). No significant variations were observed in the levels of other volatile fatty acids (VFAs) between the two groups (p > 0.05). The rumen microbial OTUs count, as well as the Shannon, Simpson, Chao1, and Ace indices, were notably lower in the STE group compared to the CON group (p < 0.05). Additionally, at the phylum level, the relative abundance of Firmicutes, Bacteroidetes, and Proteobacteria collectively accounted for over 97% of the total phylum composition. In comparison to the CON group, the STE group exhibited an increase in the relative abundance of Proteobacteria (p < 0.05), accompanied by a significant reduction in the relative abundance of Patescibacteria and Desulfobacteria (p < 0.05). At the genus level, there was a notable increase in the relative abundance of Prevotella_7 and Succinivibrionaceae_UCG_001 in the STE group, whereas the relative abundance of Rikenellaceae_RC9_gut_group significantly decreased (p < 0.05). According to the correlation analysis between rumen microflora and VFAs, the relative abundance of Succinivibrionaceae_UCG_001 displayed a significant negative correlation with AA (p < 0.05), whereas Lactobacillus exhibited a notable positive correlation with isobutyric acid (IBA) (p < 0.05). In summary, steviol glycosides had no significant effect on the production performance and blood biochemical indexes of Hu sheep. Steviol glycosides can improve rumen fermentation parameters and rumen microflora structure of Hu sheep and have a certain effect on rumen microbial diversity and composition.

A dynamic surge pricing model throughout product lifecycle

The shorter lifecycle and faster upgrading of the product make the potential demand change rapidly, thereby pricing based on market changes is critical to increasing profits. In response to changes in the potential demand, we present a dynamic surge pricing model that characterizes sales trajectories and gradient pricing. We introduce the Lotka–Volterra system to construct the sale-forecast system and prove its effectiveness in predicting the product lifecycle curve that reflects the change of the potential demand. In contrast to the linear demand function, we propose a gradient pricing mechanism based on marginal sales and total sales to describe the relationship between price and potential demand throughout the life cycle. Particularly, the dynamic surge pricing model degrades to Cournot model in the maturity phase of the market. We characterize the dynamic equilibrium and conduct the sensitivity analysis of parameters, showing that the dynamic surge pricing model outperforms Cournot model in terms of profit. A numerical example illustrates that the profit of the dynamic surge pricing model is nearly 21.82% higher than that of Cournot model.

Self-centering dual rocking core system with viscous dampers in additional rocking sections

To mitigate the high mode effects and reduce the force requirements of the structural members in the multi-story self-centering dual rocking core (SDRC) system, this paper proposes the multiple self-centering dual rocking core system with viscous dampers in additional rocking sections (MSDRCV system). The sketch and ideal working mechanisms of the MSDRCV system are interpreted. The additional rocking sections are set to decrease the force requirements of structural members and viscous dampers are included to mitigate high mode responses of the additional rocking sections, introducing seismic performance enhancement. Comparative analyses on a 9-story MSDRCV system with viscous dampers in rocking sections, a 9-story multiple self-centering dual rocking core system without viscous dampers in rocking sections (MSDRC system) and a 9-story SDRC system were carried out. The MSDRCV and MSDRC system can realize the reduction of the force demands in structural members in contrast to the SDRC system. Nevertheless, the high mode responses caused the uncontrollable displacement concentration in the MSDRC system and hence aggravated the seismic performance under rare seismic events. The analysis results in the frequency domain confirmed that the viscous dampers in the MSDRCV system can efficiently control the high-mode responses. The effects of the design parameters of the viscous dampers on the peak responses of the MSDRCV systems were comprehensively studied via parametric analyses. The results offer guidance for the viscous dampers design.

Fisetin ameliorates polycystic ovary syndrome in rats via a mechanistic modulation of AMP-activated protein kinase and SIRT1 molecular pathway.

Fisetin, a polyphenolic flavonoid, exhibits numerous pharmacological activities against metabolic syndromes. The present research aims to explore the therapeutic efficacy of fisetin in experimental polycystic ovary syndrome (PCOS). Female Sprague-Dawley rats were administered mifepristone (20mg/kg/day) to induce PCOS. PCOS rats were treated with fisetin (20mg/kg and 40mg/kg) and further compared with metformin HCl, the conventional drug for PCOS. The mechanism of fisetin was explored using dorsomorphin (an AMPK inhibitor). Then, rats were sacrificed for further analysis of biochemical and histological parameters. PCOS rats exhibited irregular estrous cycles, increased serum testosterone (4.72 ± 0.139ng/ml), estradiol (750.2 ± 16.56pg/ml), LH (30.33 ± 1.563 mIU/ml), HOMA-IR (1.115 ± 0.049), TNF-α (86.59 ± 3.93pg/ml), IL-6 (55.34 ± 4.432pg/ml), and TBARS (3.867 ± 0.193µmol/mg) along with declined progesterone (11.67 ± 1.54ng/ml), FSH (13.33 ± 1.256 mIU/ml), GSH (33.47 ± 1.348µmol/mg) levels, and SOD (2.163 ± 0.298 U/mg) activity as compared to normal control group. Fisetin high dose significantly lowers testosterone (3.014 ± 0.234ng/ml), estradiol (533.7 ± 15.39pg/ml), LH (16.67 ± 1.62 mIU/ml), HOMA-IR (0.339 ± 0.20), TNF-α (46.02 ± 2.66pg/ml), IL-6 (31.77 ± 3.47pg/ml), and TBARS (1.747 ± 0.185µmol/mg) and enhances progesterone (33.17 ± 1.447ng/ml), FSH (27.17 ± 1.42 mIU/ml), GSH (60.35 ± 1.1.102µmol/mg) levels, and SOD (4.513 ± 0.607 U/mg) activity. The histology of ovarian tissues shows a significant increase in cystic follicles in PCOS rats compared with the normal control group. These alterations were attenuated with fisetin treatment. Administration of dorsomorphin with fisetin can reverse the beneficial effects of fisetin in PCOS rats. Altogether, these present findings highlight the potential of fisetin as a promising therapeutic intervention for the management of PCOS by modulating AMPK/SIRT1 signaling in rats.

Development and research of diaphragm hydrolic diode for positive displacement pumps

On the analysis of literary sources and working processes of a positive displacement pump we established that a hydrolic diode in positive displacement pumps improves their reliability and their most efficient application is in pumps in which the process of reverse flow into the working cavity into the discharge line is insignificant in time, for example, in spur rotary pumps. We established on comparing the results of a numerical experiment on the flow of a viscous incompressible fluid in a hydrolic diode, that the k-w model most accurately describes the fluid flow in a diaphragm hydrolic diode both quantitatively and qualitatively. The performed parametric analysis of the influence of the main parameters on the fluid flow in the hydrolic diode and the diodicity proved that the distance between the hydrolic diode plates should be within 35–40 mm; the angle of inclination of the plates to the body of the hydrolic diode should be 20°−30°; the number of pairs of plates should be within 7–9 pcs.

Assessment of spatio-temporal characteristics of groundwater quality at Khordha District, India

Groundwater is the major basis for drinking in various parts of our country. However, it gets contaminated by the toxic materials found in rocks, because of which it becomes unfit for various domestic and irrigation purposes. In present study, the groundwater quality and its availability for various purposes were examined by the parameters such as pH, DO, EC, TDS, temperature, salinity, Alkalinity, Total hardness, calcium hardness, magnesium hardness, chloride, fluoride, nitrate and phosphate during the post monsoonseason of 2022 and pre monsoon season of 2023 from 49 sampling locations. The above mentioned parameters were used for assessing appropriateness of groundwater for irrigation and domestic purposes by comparing them with the Bureau of Indian standards (BIS). The results revealed that groundwater shows wide variations among various parameters between two seasons during 2022–23. Obtained results show that water used for potable purposes by people in various parts of study area doesn’t meet necessary standards.In some of the sampling locations, it is found that the water exhibits very poor quality or unfit maybe for one season or both seasons. Analysis of parameters is done for calculating correlation coefficient of specified parameters. Strong linear relationships, both positive and negative, were found between several pairs of water quality measures according to their research.

Dynamic response of girder bridges with corrugated steel webs subjected to moving loads

Girders with corrugated steel webs (CSWs), replacing traditional concrete webs in prestressed concrete box girders, exhibit a unique dynamic behavior due to the accordion effect and the thinner dimension of CSWs. The study aims to investigate the dynamic response of girder bridges with CSWs under moving loads. Utilizing the Timoshenko beam theory and modal analysis method, the analytical formula for the dynamic response, considering shear deformation and rotational inertia, was developed. The proposed analytical formula was validated through finite element simulation. Employing dimensionless parameters, a parametric analysis was conducted to examine the effects of multi-modes, loading position and shear deformation on the dynamic response of girders with CSWs. The results highlight the significant influence of the shear parameter αS and the speed parameter SE1 on the magnitude of the impact factor. Precise calculations for deflection and bending moment only require consideration of low-order modes, whereas accurate estimation of shear force requires attention to higher-order modes. In particular, a high-frequency resonance phenomenon is identified when the speed parameter SE1 and the shear parameter αS conform to the formula “πSE1αS = 1”. The suggested impact factor formulas for midpoint deflection, midpoint bending moment and end shear force have been developed and categorized into three groups based on the magnitude of the shear parameter αS.

Application of a folded nanostructure reinforcement for the pole vault curved shell

Foldability capacity is now introduced as a novel nanofiller reinforcement production procedure using some operation to control the mechanical, thermal and electrical properties in the sport equipment. Application of this type of nanofillers in the curved structures like pole vault shell leads to a novel engineering and sport shell shape structures. This article is organized to suggest a vibration-based formulation for analysis of folded reinforced curved shell sport structure subjected to thermal and mechanical loading. Using computation of kinetic, strain and external energies, one can arrive the motion’s equations using the minimization of total energy and Hamilton’s principle. Using solution of the motion’s equations through an analytical approach, the parametric analysis is presented. The verified test is presented for confirmation of the solution and trend of results.

Parametric analysis of nonstructural component acceleration response spectra considering interaction between structures and nonstructural components

AbstractThe nonstructural component–structure interaction (NSI) is a critical aspect in addressing the seismic design of structures and nonstructural components. However, the NSI is not considered in generating acceleration spectrum, which is the most commonly used tool for seismic design. To study the pattern of the NSI affecting acceleration response spectra of nonstructural components and floors, the acceleration response spectra of a benchmark steel frame structure with different parameters were calculated using a numerical method after the accuracy of the numerical method was verified by carrying out shaking table tests. These parameters are the damping ratio of the nonstructural component, the weight ratio of the nonstructural components to the floor, and the frequency ratio and height ratio of the nonstructural component to the structure. The influence of each parameter on acceleration response spectra was derived by comparing different spectra. The trend of acceleration response spectra of the nonstructural component with different combinations of parameters was compared to determine whether each parameter is relatively independent. This parametric analysis can be applied to calculating acceleration response spectra of the nonstructural component while considering the NSI.

USAGE OF TECHNICAL MEANS FOR ANNULAR GAS EXTRACTION TO INCREASE OIL WELL PRODUCTION

In recent years, the technology of annular gas extraction from wells has become increasingly widespread in the fields in order to improve the working conditions of the submersible pump due to increasing its filling and supply coefficients, as well as increasing depression on the formation. Some types of compressor designs have been developed and put into production, allowing the annular gas extraction from wells and forced injection into the pressure line of the well. One of the most well-known types of compressors is a piston pair driven by a piston from a rocking machine balancer. They were used at oil production facilities in the Orenburg, Ulyanovsk Regions, the Republics of Tatarstan and Bashkortostan, Udmurtia and other regions of the Russian Federation.In the fields of Sheshmaoil LLC, a complex for pumping gas from the annulus of a well and pumping it into the COGS product collection system has found mass usage, allowing gas to be taken from a group of wells and reducing pressure in the annulus to values close to 0.1 MPa. Hydraulic piston compressors, in which gas compression occurs using a high-pressure pump that drives the piston group of the compressor, have been tested.One of the main disadvantages of the developed types of compressors is the insufficient volume and pressure of the compressed gas. The article provides an analysis of the technological parameters of the compressors. As a result of research possible solutions to the problem are worked out.To achieve the largest pumping volumes of separated annular gas, the maximum permissible diameter of the compressor cylinder should not exceed 0.07 m in order to prevent significant resistance exerted by the piston rod on the balancer of the pumping machine.The most suitable region for the effective use of suspended compressors is the Ural-Volga Region at fairly depleted oil fields with at least 60–65 % water cut, oil well flow rate of no more than 10–15 tons/day and a gas factor of no more than 15–20 m3/t . At the fields of Western Siberia, suspended compressors cannot be used due to high flow rates and gas factors. Exceptions may be wells with a water cut of at least 80 % and flow rates of no more than 20–25 tons/day.The KOGS compressor unit, developed and widely implemented at Sheshmaoil Management Company LLC, showed positive results, consisting of an increase in flow rate and additional oil production. For further use of the unit in fields, especially for high-viscosity oil production, as well as operation in winter conditions, it is necessary to increase the maximum gas injection pressure.

O-261 Frozen gametes differ in post-insemination dynamics to their fresh sibling counterparts in cycles using testicular sperm

Abstract Study question Are there differences in post-insemination events between fresh and frozen-derived gametes when testicular sperm extraction (TESE) is used? Summary answer Frozen-TESE leads to decreased fertilization, but not blastocyst euploidy rates; 2PN-lag time is significantly longer when frozen gametes are utilized compared to their fresh counterparts What is known already Studies indicate that the origin of testicular sperm influences the development potential of cleavage-stage embryos into blastocysts. Recent morphokinetic analysis suggest that embryos from frozen-TESE exhibit prolonged pronuclear stages and more frequent uneven cleavage compared to those from ejaculated sperm. Notably, no comparison with fresh-TESE was performed. To date, no studies have explored analysis in embryo morphokinetic parameters comparing fresh and frozen-TESE, especially when derived from the same patient.Such comparisons could provide a more accurate understanding of potential differences. Given that TESE occasionally involves the use of vitrified oocytes, it is essential to thoroughly examine outcomes across all combinations. Study design, size, duration Retrospective cohort study in a tertiary referral IVF centre including 72 cycles of 30 couples between January 2017 to September 2023. Following insemination by TESE-sperm, embryos were cultured in time-lapse (TL) incubator. Blastocysts ≥BL3CC (Gardner’s) underwent trophectoderm (TE) biopsy for Preimplantation Genetic Testing for aneuploidy (PGT-A) by next generation sequency (NGS). Participants/materials, setting, methods Gamete sources were fresh (fresh-TESE) or frozen-thawed-TESE (frozen-TESE) from the same patients with non-obstructive azoospermia (NOA), and fresh or vitrified (frozen) oocytes from the same female partner. Fertilization, usable blastocysts, and euploidy rates were recorded. Morphokinetics were annotated for time (t) of PB2 (tPB2), tPNa (PN-appearance), tPNf (PN-fading), t2-t9, CP (compaction), tM (Morula), tSB (start blastulation), tB (blastocyst) and timings between each developmental event. Main results and the role of chance Among included 980 oocyte/TESE dyads, 253 (25.8%) used fresh oocyte/sperm, 141 (14.4%) frozen oocyte/fresh sperm, 558 (56.9%) fresh oocyte/frozen sperm and 28 (2.9%) frozen oocyte/sperm. In oocyte/sperm dyads using fresh-TESE, normal fertilization (2PN) (52.0% vs. 44.5%) were higher compared to dyads using frozen-TESE (P &amp;lt; 0.01). Mixed-effects logistic-regression accounting for dependency structure between oocytes/sperm dyads of the same couple, showed an association of frozen-TESE with lower fertilization (OR: 0.64, 95%CI: 0.45-0.89, P = 0.008) and lower blastulation (³BL3CC)/MII (OR: 0.53, 95%CI: 0.37-0.77, P = 0.001), but similar blastulation (³BL3CC)/2PN (OR: 0.69, 95%CI: 0.45-1.07, P = 0.09). After accounting for female age, euploidy per tested blastocyst was similar whether fresh or frozen sperm was used (OR: 0.91, 95% CI: 0.46-1.79, P = 0.788). Frozen oocyte use on the other hand was not significantly associated with these outcomes (P &amp;gt; 0.05 for all). Analysis of morphokinetic parameters revealed that use of frozen dyads was associated with longer duration of 2PN after tPNa to tPNf: in frozen-TESE, 2.10h longer (95%CI: 0.55-3.64, P = 0.008); and in frozen oocytes, 2.34h longer (95%CI: 0.31-4.36, P = 0.024). Among embryos reaching blastulation, frozen-TESE embryos reached 6-cell stage earlier (tPNf to t6, 2.4h earlier, P = 0.009) but they were somewhat delayed in reaching expansion from there on (t6 to tEB, 4.4 hours later, P = 0.059). Limitations, reasons for caution In certain oocytes, insemination was conducted using either fresh or frozen immotile sperm that showed unresponsiveness to activation methods. However, the samples size hinders a comprehensive comparison. Wider implications of the findings Use of frozen-thawed TESE from NOA-patients may decrease fertilization and consequently lower blastocyst yield, but not euploidy rates. Synchronizing fresh-TESE with oocyte retrieval appears safer to maximize fertilization. Regardless of the gamete type, frozen-sourced sperm or oocyte impact 2PN-lag time, possibly indicating nuclear repair mechanisms post-freezing, requiring further investigation. Trial registration number 2310-ABU-020-VF

Traumatic Brain Injury as an Independent Predictor of Futility in the Early Resuscitation of Patients in Hemorrhagic Shock.

This review explores the concept of futility timeouts and the use of traumatic brain injury (TBI) as an independent predictor of the futility of resuscitation efforts in severely bleeding trauma patients. The national blood supply shortage has been exacerbated by the lingering influence of the COVID-19 pandemic on the number of blood donors available, as well as by the adoption of balanced hemostatic resuscitation protocols (such as the increasing use of 1:1:1 packed red blood cells, plasma, and platelets) with and without early whole blood resuscitation. This has underscored the urgent need for reliable predictors of futile resuscitation (FR). As a result, clinical, radiologic, and laboratory bedside markers have emerged which can accurately predict FR in patients with severe trauma-induced hemorrhage, such as the Suspension of Transfusion and Other Procedures (STOP) criteria. However, the STOP criteria do not include markers for TBI severity or transfusion cut points despite these patients requiring large quantities of blood components in the STOP criteria validation cohort. Yet, guidelines for neuroprognosticating patients with TBI can require up to 72 h, which makes them less useful in the minutes and hours following initial presentation. We examine the impact of TBI on bleeding trauma patients, with a focus on those with coagulopathies associated with TBI. This review categorizes TBI into isolated TBI (iTBI), hemorrhagic isolated TBI (hiTBI), and polytraumatic TBI (ptTBI). Through an analysis of bedside parameters (such as the proposed STOP criteria), coagulation assays, markers for TBI severity, and transfusion cut points as markers of futilty, we suggest amendments to current guidelines and the development of more precise algorithms that incorporate prognostic indicators of severe TBI as an independent parameter for the early prediction of FR so as to optimize blood product allocation.

Integrated analytical, experimental, and numerical study of vibrational response in clamped circular plates with pressurised air cavities

This paper presents a comprehensive investigation, comprised of analytical, experimental and numerical approaches, into the interaction between the sound field produced within a pressurised air-filled back cavity and the vibration of a thin clamped circular plate subjected to its pressure. Previous investigations into the interaction of sound fields with vibrating boundaries have primarily been restricted to non-pressurised cavities. We extend the application of the weak modal coupling method to derive a solution for this unexplored physical problem by utilising classic plate theory, Fourier-Bessel series formulation and the uncoupled solutions for a pressurised cylindrical sound field and a thin clamped circular plate with uniform radial tension. We describe the vibration response of the coupled system in terms of the uncoupled cavity and plate modes. Using a set of geometric and physical properties for the system, the resonance frequencies and response functions are calculated and the coupling between the sound field and the plate is investigated as a function of cavity pressure, providing novel fundamental insights into the physical system. We construct an experimental rig to embody the conditions of the analytical investigation for the purpose of validation. Finite element analysis (FEA), employing modal analysis and transient dynamic analysis, is used to further validate and extend the analytical insights while more accurately mirroring the experimental conditions. The response functions, mode shapes, resonance frequencies and their dependence on the cavity pressure were experimentally measured and numerically simulated, with direct comparisons made with the analytical model. A high degree of accuracy for the analytical model is validated along with its ability to describe the underlying physical phenomena. The validated analytical model is then leveraged to perform fundamental explorations into the modal contributions as a function of cavity pressure and a parametric sensitivity analysis on the effects of plate radii and plate thickness on the coupled system resonance frequencies.

P-023 Gene expression in human sperm as biomarkers and tools for the assessment of male infertility

Abstract Study question Can gene expression as AURKA, HDAC4, and CARHSP1 be used for the diagnosis of sperm quality exploring male infertility? Summary answer The comprehensive outcome of gene expression involving AURKA, HDAC4, and CARHSP1 serves as a key to classifying sperm and predicting their functionality. What is known already Diagnostic male infertility is largely based on semen parameters according to the World Health Organization (WHO) reference values. While these parameters assess sperm quality, they do not provide insights into sperm quality and have a limited predictive value on natural fecundity, fertilization rates, and assisted reproductive technology (ART) outcomes. Study design, size, duration This prospective study investigates the gene expression involved in mitosis, epigenetic regulation, and early embryo development. From February to June 2023, we included all men aged from 20 to 60 years having sperm parameters analysis in our unit center. A total of 277 semen samples were collected, 129 (46.4%) exhibiting three normal sperm parameters according to WHO criteria. Among these, 32 samples showed oligo-astheno-teratozoospermia (OAT), while 116 samples had 1 or 2 abnormal parameters. Participants/materials, setting, methods The mRNA expression levels of three candidate genes (AURKA, HDAC4, and CARHSP1) were quantified in fresh ejaculate semen using real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The thresholds for the spermatozoa function index (SFI) were established by assessing the combined expression of these target genes, considering the morphology and the capability to reach a blastocyst stage. The sperm were ranked according to the concentration (million/ml), motility (%) and morphology (%). Main results and the role of chance We assess the quality of spermatozoa for three biomarkers by analyzing their mRNA expression levels. Receiver operator characteristics curves (ROC) indicate a combined index value expression. This model establishes an index threshold &amp;gt; 320 for an “over-index value,” distinguishing spermatozoa with a normal capacity, an index threshold &amp;lt; 290 for an “under-index value,” and 290 &amp;lt; index &amp;lt; 320 for an “intermediate-index value”. Among the 277, we find 112 (40.4%) have an over-expression index; 161 (58.1%) have an under-expressed index and 4 (1.4%) have an intermediate-index. Interestingly, among the 129 samples with the three normal WHO parameters, we show that 82 (63.5%) have an over-index value, 44 (34.1%) have an under-index value, and 3 (2.3%) display an intermediate-index value. In addition, all the 32 OAT samples have an under-index. These findings suggest that the OAT sperm population implies a potential epigenetic network connected with our three target genes. Furthermore, even in cases with normal sperm parameters, there may be an under-expressed index, indicating lower functionality in terms of fertilization and early embryo development. Limitations, reasons for caution The present method was validated only on ejaculate semen in men free of any chronic disease and any anti-oxidant treatment. This prospective study requires further validation in the largest population. Wider implications of the findings This study’s results could highlight understanding a chaotic early embryo development in ART and used to explore male infertility; particularly in unexplained infertility. Trial registration number not applicable

Dynamic examination of closed cylindrical shells utilizing the differential transform method

This article presents an innovative approach using the Differential Transform Method (DTM) to analyze the vibration characteristics of cylindrical shells, integrating Taylor's series with Sander's classical theory. It demonstrates DTM's efficiency, accuracy, and potential as an alternative method. The study introduces a novel application of the DTM in exploring the free vibration of cylindrical shells, detailing a technique to address challenges such as normalization, linear solution methodologies, and parameter derivative modifications. A dimensionless parameter analysis evaluates the impact of length, radius, thickness, and modulus of elasticity. Comparative analysis with Hybrid Finite Element Method (FEM) data and validation against existing literature highlights DTM's precision and reliability. In conclusion, DTM offers a robust solution for the eigenvalue problem in coupled differential equations, providing accurate vibration parameters. Additionally, an important relationship between the modulus of elasticity and frequency in the dimensionless state was obtained.

The Influence of the Delamination Location on the Bending Behavior of E-Glass Fiber EWR Flat Plates

The paper presents a study on the stresses and deformations induced by the transversal loading of some flat plates made of E Glass EWR Fiberglass Woven Roving type, having delamination type defects. The parametric analysis of the delamination influence on the stresses and displacements occurring in the plate material is performed. The results of the static calculation are compared with the experimental tests of the flat plates subjected to bending, highlighting the concordance of the variation of the stresses and displacements versus to the position of the delamination position.

A new salt-precipitation-based self-remediation model for CO2 leakage along fault during geological CO2 storage

Salt precipitation occurring in fault zone, due to CO2-brine co-leakage, would create an opportunity to prevent CO2 leakage along fault, i.e., salt-precipitation-based self-remediation model. To investigate the new model, the physical model on salt precipitation was proposed, considering co-leakage of CO2 and brine along fault. Theoretical model was given on salt precipitation, and the numerical model was established to validate the salt precipitation occurring in fault zone. The numerical results indicated that salt precipitation indeed occurred in fault zone, and CO2 leakage rate was obviously decreased after salt precipitation. Importantly, evolution of salt precipitation in fault was concluded, from viewpoint of co-leakage of CO2 and brine along fault, and degree of salt precipitation was characterized, using representative parameters such as the starting time, ending time, lasting time of salt precipitation, and solid saturation. Especially, the self-remediation model for CO2 leakage based on salt precipitation was confirmed feasibly. The self-remediation capacity was closely related to degree of salt precipitation (or lasting time of salt precipitation), and was directly evaluated by the decreasing in CO2 leakage rate before and after salt precipitation. Finally, the parametric analyses showed that: (1) the potential correlation was found among the lasting time of salt precipitation, solid saturation and self-remediation capacity; (2) the higher CO2 injection rate and fault permeability, the smaller fault width and permeability of lower saline aquifer were helpful for salt precipitation and self-remediation capacity; (3) no salt precipitation occurred for the smaller CO2 injection rate and fault permeability, the larger fault width and permeability of lower saline aquifer.

Assessment of resistance to crack propagation of asphalt mixtures using two parts digital image correlation

The use of recycled aggregates in the manufacturing of asphalt concrete is becoming increasingly widespread. This requires special attention to characterize their performance in terms of durability to reduce major maintenance and rehabilitation expenditures. To achieve this, it is necessary to use effective and easy-to-implement test procedures to observe and estimate the various damage and cracking processes that often lead to the structural failure of materials. Many studies have shown that the estimation of cracking energy depends on the extent of damage and cracking processes. In this context, the method of estimating the crack propagation path and the accompanying damage strongly influence the calculated value of the fracture energy. This can lead to an overestimation or underestimation of the material’s performance. Based on these considerations, our aim is to introduce a new approach for improving the estimation of cracking processes to assess resistance to crack propagation. A three-point bending test was conducted on recycled bituminous concrete samples with a single notch at two distinct temperatures, −5 °C and 10 °C. The extent of the cracking process and damage was estimated using 2PDIC, a two-part digital image correlation method. The parametric analysis of the measurements obtained by 2PDIC reveals that defining the pseudo-strain threshold enables the observation of different amplitudes and levels of strain associated with the various processes that accompany the cracking test. The results obtained for the two temperatures considered demonstrate a significant change in cracking energy, which is often overestimated and depends on the crack propagation path and the granular arrangement of the material through which the crack passes. The measurements obtained using 2PDIC also demonstrate the greater tortuosity of the crack propagation path at higher temperatures, which results in a reduction of the estimated cracking energy derived from more simplistic approaches.

Kinetic insights and pollution mitigation in waste tire pyrolysis: Targeting sulfur, nitrogen, and PAHs emissions

Waste tires have potential to be used for generation of fuel via thermal degradation because of their non-biodegradable nature. Nevertheless, the formation of various pollutants such as sulfur-based and nitrogen-based are inevitable due to presence of nitrogen and sulfur containing compounds during waste tires production. The main purpose was to examine the effect of variating heating rates on pollutants release because heating rate is an important parameter which influences the pollutants releasing profile. Moreover, Ar and CO2 as reaction medium were used to identify their behavior for restraining the PAHs in gas phase. The present study investigates the influence of heating rates and carrier gas environment (Argon and CO2) to reduce the pollutants emission. Thermogravimetry-Mass Spectrum coupled with Fourier transform infrared spectrometer was used to evaluate the thermal degradation and pollutants formation. The major degradation of waste tires occurred between 300 and 500 ℃. The sulfur-based (H2S, CS2, COS, SO2, and CH3SH), nitrogen-based (NH3, HNCO, NO, and HCN) and 9 series of PAHs pollutants were detected. The higher heating rates promoted the pollutants emission. The degradation of compounds having sulfur content formed -SH radials and -SH helped in further release of sulfur based-pollutants. The NH3 releasing profile started after 200 ℃ and released till around 800 ℃ for 30 ⁰C/min and 40 ⁰C/min but its emission was very low after 600 ⁰C for heating rates 5 ⁰C/min, 10 ⁰C/min, and 20 ⁰C/min. The aromatic compounds fraction was more at higher heating rate due to short residence time for pyrolytic products to go through secondary reaction. The 5 ℃/min and 10 ℃/min were considered favorable heating rates in terms of achieving lowest activation energy in both gas environments. The thermodynamic parameters analysis suggested that waste tires pyrolysis was non-spontaneous and endothermic reaction as well as feedstocks showed potential to be utilized for waste conversion.

Data-driven prediction on critical mechanical properties of engineered cementitious composites based on machine learning

The present study introduces a novel approach utilizing machine learning techniques to predict the crucial mechanical properties of engineered cementitious composites (ECCs), spanning from typical to exceptionally high strength levels. These properties, including compressive strength, flexural strength, tensile strength, and tensile strain capacity, can not only be predicted but also precisely estimated. The investigation encompassed a meticulous compilation and examination of 1532 datasets sourced from pertinent research. Four machine learning algorithms, linear regression (LR), K nearest neighbors (KNN), random forest (RF), and extreme gradient boosting (XGB), were used to establish the prediction model of ECC mechanical properties and determine the optimal model. The optimal model was utilized to employ SHapley Additive exPlanations (SHAP) for scrutinizing feature importance and conducting an in-depth parametric analysis. Subsequently, a comprehensive control strategy was devised for ECC mechanical properties. This strategy can provide actionable guidance for ECC design, equipping engineers and professionals in civil engineering and material science to make informed decisions throughout their design endeavors. The results show that the RF model demonstrated the highest prediction accuracy for compressive strength and flexural strength, with R2 values of 0.92 and 0.91 on the test set. The XGB model outperformed in predicting tensile strength and tensile strain capacity, with R2 values of 0.87 and 0.80 on the test set, respectively. The prediction of tensile strain capacity was the least accurate. Meanwhile, the MAE of the tensile strain capacity was a mere 0.84%, smaller than the variability (1.77%) of the test results in previous research. Compressive strength and tensile strength demonstrated high sensitivity to variations in both water-cement ratio (W) and water reducer (WR). In contrast, flexural strength exhibited high sensitivity solely to changes in W. Conversely, the sensitivity of tensile strain capacity to input features was moderate and consistent. The mechanical attributes of ECC emerged from the combined effects of multiple positive and negative features. Notably, WR exerted the most significant influence on compressive strength among all features, whereas polyethylene (PE) fiber emerged as the primary driver affecting flexural strength, tensile strength, and tensile strain capacity.