Maximum Decrease Research Articles

Improving the accuracy of vortex beam rotational velocity measurement based on phase recovery and polarization reference

In remote rotational velocity measurements, atmospheric turbulence-induced phase distortion of the vortex beam increases velocity measurement error (VME). Previous studies overlooked the reference to new dimensional information for measurement error analysis and accuracy enhancement. Our work proposes the Optimal Joint Reference VME (OJR-σ) method as a, to our knowledge, novel error optimization method; it references the measurement error information from the left- and right-handed polarized components (LP and RP) of the polarized vortex beam and optimizes the velocity measurements values weights of LP and RP in the result to minimize the VME. Combined with the GS phase recovery algorithm, this method effectively reduces system VME, enabling distortion compensation and optimal VME mode distribution evaluation. The results indicate that the OJR-σ method achieves a lower VME advantage across all modes compared to both the General Joint Reference VME (GJR-σ) and General VME (G-σ) methods, with maximum VME decreases of 29% and 71% for the High VME decline rate modes, respectively. Additionally, the OJR-σ method exhibits fewer High VME modes, resulting in an average VME of 83.6% and 71.0% compared to the other two methods. After GS compensation, the VME of High VME modes decreases by 6.12%, 4.7%, and 6.78% for the three error methods, respectively. Furthermore, the OJR-σ method proves more effective than GJR-σ in reducing the VME for high topological charge modes, achieving a decline reaching 69.9%. Our work combines the phase recovery algorithm with the reference of measurement error information from both polarization dimensions, significantly reducing VME and demonstrating the potential of polarized vortex beams in high-precision applications. This innovatively provides, to our knowledge, a novel method and theoretical support for further enhancing the accuracy of free-space rotational velocity measurements.

Impact of introducing electric vehicles on ground-level O3 and PM2.5 in the Greater Tokyo Area: yearly trends and the importance of changes in the urban heat island effect

Abstract. Battery electric vehicles (BEVs) are considered a solution for global warming and air pollution, and several countries have announced they will shift to BEVs in the 2030s. Even though previous studies have shown the effects of reducing vehicular emissions on the formation of tropospheric ozone (O3), no studies have evaluated the effect of decreasing anthropogenic heat, which is expected to mitigate urban heat island (UHI) effect, on air quality issues. We used a numerical weather prediction to estimate changes in the UHI effect in the Greater Tokyo Area (GTA) of Japan by introducing BEVs. The results indicated that the introduction of BEVs would lead to a maximum local temperature decrease of 0.25 °C in the GTA. The effects of introducing BEVs on O3 and fine particulate matter (PM2.5) were estimated using a regional chemical transport model. The results indicated that mitigating the UHI effect would lead to a reduction in ground-level O3 formation. This is due to the increased NO titration effect caused by the lowered planetary boundary layer height and due to the degradation of photochemistry related to O3 formation caused by a decrease in temperature and biogenic volatile organic compounds (BVOCs). The mitigation of UHI would result in enhanced particle coagulation, with an increase in ground-level PM2.5. Furthermore, a decrease in BVOC emissions would result in increased PM2.5 owing to enhancement of the OH + SO2 reaction. A total of 175 and 77 annual premature deaths would be prevented from changes in O3 and PM2.5, respectively.

Advanced parametric optimization of a nanofluid augmented PCM-based latent heat thermal energy storage system

With the increase in energy crises and consequently the rapid depletion of fossil fuels, harnessing solar energy is imperative and on the rise. However, the storage of solar energy for retention and later use demands the need for optimized and efficient storage systems. This study is concerned with the evaluation of various parameters affecting the performance of a packed bed latent heat storage system. Additionally, this work proposes utilizing four different types of paraffin PCMs as encapsulation fillings and five different types of novel heat transfer fluids (HTFs). Furthermore, an improved optimization was carried out to arrive at the best charging time. This analysis was carried out by discretizing the governing equations using a finite element scheme under suitable boundary conditions.The results suggest that the charging time depicts a distinct U-shaped curve between the considered porosity values of 0.15 and 0.7. The results show a maximum reduction of 9.37% in charging time when the bed porosity is 0.35. Additionally, increasing the water flow rate to 25 l/min causes the charging to complete in 10.125 h. Similarly, the reduction in encapsulation size shows maximum decrease at both 15 and 20 mm to be 6.10%. Cumulatively, at the optimized individual parameters, the charging time drops to just 9.25 h, thus showing the maximum decrement in charging time of 14.54% for the PCM storage medium RT56-58 in conjunction with the nanofluid designated as slurry(S).

Study on the Mechanical Properties of Modified Sludge Soil Based on an SM-C Modifier

The purpose of this study is to solve the problem of the harmless treatment of dredged silt and soil extraction during road construction in lake areas. The silt in the project area is used as the research material to evaluate its engineering applicability as an improved filling material for the roadbed of the lake’s surrounding road. Through indoor pretreatment and a series of mechanical performance tests, including compaction tests, unconfined compressive strength tests (UCS), bearing ratio tests (CBR), triaxial compression tests (CU consolidated undrained), and consolidation tests, we obtained key mechanical parameters of modified sludge soil, such as maximum dry density, optimal moisture content, unconfined compressive strength, bearing ratio, shear strength, and compression characteristics. The research results show that with the increase in modifier dosage, the optimal moisture content of modified sludge soil increases, the maximum dry density decreases, and its compressive strength and shear strength significantly improve. The CBR value also meets the technical requirements of each layer of the roadbed. Specifically, after 7 days of curing, the compaction degree of 10% modified sludge soil can exceed 96%, the unconfined compressive strength reaches 0.819 MPa, the CBR value reaches 17.5, the cohesion measured by triaxial tests is 78 kPa, the internal friction angle is 27°, and it exhibits low compressibility. These findings provide new solutions for environmentally friendly treatment, resource utilization, and road engineering in river and lake sediments.

Numerical Study on the Effect of Tunnel Slope on Smoke Exhaust Performance in Metro Tunnels

Utilizing the intermediate air shaft for smoke exhaust is one of the crucial emergency ventilation methods in metro tunnel fires. To study the impact of metro tunnel slope on smoke exhaust performance of intermediate air shaft, this paper employs numerical simulation to conduct research from the following aspects: the longitudinal distribution of ceiling smoke temperature, visibility distribution, smoke layer height, and the smoke exhaust efficiency of intermediate air shaft. The results demonstrate that as the tunnel slope increases, the maximum ceiling temperature decreases, and the visibility at dangerous height increases. The smoke layer height on the downhill side of a sloped tunnel is higher than that of a horizontal tunnel, while the smoke layer height on the uphill side is lower. Under single-side smoke exhaust mode, the smoke exhaust efficiency of the 2# intermediate air shaft rises as the tunnel slope increases. However, under air supply plus smoke exhaust mode, the smoke exhaust efficiency of the 2# intermediate air shaft decreases with the growing tunnel slope.

Thermal properties of Al2W3O12/epoxy composites at low filler volume loadings

AbstractThe open‐framework Al2W3O12 ceramic has been perceived as a candidate for controlling the coefficient of thermal expansion (CTE) of polymer matrices due to its low positive CTE and simple low‐cost soft‐chemistry synthesis. Hence, this work aims to study the effect of Al2W3O12 submicronic fillers at low loadings (0.46–1.43 vol%, i.e. 2.0–6.0 wt%) on thermal properties of epoxy‐based composites. The composites were prepared by ultrasonic filler dispersion followed by casting, and characterized through thermomechanical and thermogravimetric analyses. The maximum decrease (11.5%) on the composite CTE in the glassy region was attained with 0.94 vol% Al2W3O12 (4.0 wt%), the highest reported for these open‐framework fillers reinforcing epoxy at low volume fractions. Experimental CTE values contrasted with predictions from micromechanical models, revealed that elastic constants of both phases and filler agglomeration state, cannot be disregarded in predicting the composite CTE. The filler did not affect the onset and the maximum degradation rate temperatures of epoxy, while glass transition temperature was increased (2%–11%) for filler loadings <1.43 vol% (<6 wt%). A higher residue char in the composites suggested that Al2W3O12 can partially prevent the volatiles release from matrix to the atmosphere.Highlights Al2W3O12 is an excellent inexpensive filler for CTE controlling due to its low CTE. Incorporation of Al2W3O12 in an epoxy matrix reduces the CTE in the glassy state. The maximum CTE reduction (11.5%) was achieved for a filler content of 0.94 vol.%. The glass transition temperature of composites increased in the range of 2–11 %. Al2W3O12 can act as a barrier to prevent the transfer of volatiles from the matrix.

Semi-Active Suspension Design for an In-Wheel-Motor-Driven Electric Vehicle Using a Dynamic Vibration-Absorbing Structure and PID-Controlled Magnetorheological Damper

Abstract: The in-wheel motor (IWM) powertrain layout offers greater design flexibility and higher efficiency of an electric vehicle but has limited commercial success mainly due to the concerns of increased unsprung mass. This paper proposes a semi-active suspension system for in-wheel motors that combines both a dynamic vibration-absorbing structure (DVAS) and a PID-controlled MR damper, in order to achieve optimised comfort, handling and IWM vibration for a small car application. Whilst PID control and DVAS are not entirely new concepts, the usage of both optimisation techniques in a semi-active in-wheel motor suspension has seen limited implementation, which makes the current work novel and significant. The semi-active suspension operating both in passive fail-safe mode and full feedback control was compared to a conventional in-wheel motor passive suspension in terms of sprung mass acceleration, displacement, stator acceleration, tyre deflection and suspension travel for three different road profile inputs using MATLAB/Simulink. The implementation of a PID-controlled MR damper improved road comfort and road holding performance and decreased in-wheel motor vibration over the DVAS passive suspension mainly in terms of a maximum peak amplitude decrease of 40%, 35% and 32% for the sprung mass acceleration, tyre deflection and stator acceleration, respectively. The results are significant since they show that the use of a simple, easily implemented control scheme like PID control was able to significantly improve IWM suspension performance when paired with a DVAS. This study provides further confidence to manufacturers to commercially develop and implement the IWM layout as its major disadvantage can be reasonably addressed using a simple readily available control approach.

A Comparative Study on Drought Stress Response In Vitro and In Vivo Propagated Fragaria vesca Plants

The evaluation of plant responses to water deficit in the substrate, particularly in the context of intensifying climate change, represents a critical factor for ensuring stable agricultural production, economic resilience, and food security. The primary objective of this study was to compare the physiological and biochemical responses to water deficit in conventional cultivation of Fragaria vesca plants propagated both in vitro and in vivo. The research encompassed measurements of gas exchange parameters, chlorophyll “a” fluorescence, photosynthetic pigment and proline content in leaves, leaf relative water content index, total fruit yield, single fruit weight, fresh and dry mass of the root system, as well as the concentrations of K, Ca, Mg, Na, Cu, Zn, Mn, and Mo. Additionally, the ratio of monovalent to divalent cations in leaves, roots, and crowns was analyzed. The results revealed significant differences between the experimental variants under optimal conditions and their respective responses to drought stress. Plants derived from in vitro cultures, despite exhibiting initially lower physiological trait values, demonstrated higher yield potential (no significant difference in the yield of fresh fruit mass compared to a 78% reduction). However, a long-term lack of water caused greater damage to their photosynthetic system—a reduction in physiological traits to 80% was observed, compared to a maximum decrease of 40% in plants derived from seedlings. The results highlight that environmental conditions and the acclimatization process of plants derived from in vitro cultures can significantly influence their adaptive potential and productivity.

Partial discharge inception voltage in PCB defect samples under different frequencies of alternating sine wave voltage

Abstract As the application of power electronic components in renewable and green energy technologies continues to increase, there is an increasing trend in the utilization of higher voltage and frequency levels. This shift may result in more frequent partial discharge (PD) phenomena that can accelerate the degradation of insulation materials and shorten the lifespan of the components. Therefore, it is critical to ensure the reliability and durability of these components. This study investigated the effects of voltage magnitude and frequency on the PD and insulation degradation of printed circuit board (PCB) samples. Five different test samples were fabricated using a PCB as the substrate and an epoxy resin as the insulating coating. Two distinct testing configurations were employed: one for assessments based on a commercial frequency (60 Hz) and the other for assessments based on a high frequency (600 Hz). This study examined the behavior of PD within PCBs and the resulting insulation deterioration. The results demonstrated that all the samples exhibited significantly lower PD inception voltages (PDIV) at high frequencies compared with those at the commercial frequency. Specifically, the maximum decrease in the PDIV observed was 5 kV, while the minimum reduction was 3.3 kV. These findings highlight the critical impact of frequency on the PD behavior and underscore the importance of understanding these effects to enhance the reliability of electronic components in high-frequency applications.

43 G>T polymorphism in the sucrase-isomaltase gene in the Chinese population prevents the glucose-lowering effect of acarbose.

Acarbose is an α-glucosidase inhibitor widely used clinically for its significant hypoglycemic effect, albeit with inter-individual variations in response. The sucrase-isomaltase (SI) enzyme is the primary target of acarbose. This study aims to investigate the impact of genetic polymorphisms in the SI gene on the pharmacodynamics of acarbose. The Illumina sequencing platform and variation-related databases were employed to analyze probable gene polymorphism sites of SI. Based on the SI polymorphism sites, Chinese subjects (n=66) were categorized into the wild-type homozygous group (Group A) and the heterozygous variant group (Group B, SI 43 G>T). The validated hexokinase method was utilized to determine glucose concentrations in participants' serum samples. The differences in blood glucose concentration reduction and pharmacodynamic parameters peak concentration (Cmax) and area under the curve (AUC0-2h) after administering the same dose of acarbose were analyzed between the two groups of subjects. Our results showed that the mean changes in glucose Cmax, AUC0-2h, maximum increase, and maximum decrease in Group B were each lower by 67.66%, 63.05%, 53.17%, and 50% compared to Group A (all p<0.05). These data suggested that genetic polymorphism of the SI gene can significantly influence the hypoglycemic efficacy of acarbose, and the polymorphism of SI is associated with individual differences in clinical treatment outcomes.

Locomoting non-magnetic marbles through meniscus emerged on the water surface using a magnetically actuated ferrofluid marble under pulsating and steady magnetic fields.

Recent progress in digital microfluidics has revealed the distinct advantages of liquid marbles, such as minimal surface friction, reduced evaporation rates, and non-wettability compared to uncoated droplets. This study provides a comprehensive examination of an innovative technique for the precise, contamination-free manipulation of non-magnetic water liquid marbles (WLMs) carried by a ferrofluid liquid marble (FLM) under the control of direct current (DC) and pulse-width modulation (PWM) magnetic fields. The concept relies on the phenomenon in which an FLM and WLMs form a shared meniscus when placed together on a water surface, causing the WLMs to closely track the magnetically actuated FLM. The study also explores the dynamic behavior of the marbles by assessing several influencing parameters: magnetic coil current, the starting position of the marbles from the coil, the number of WLMs carried by the FLM, the volume ratio between the WLM and FLM, and the PWM magnetic field properties, including duty cycle and frequency. The results demonstrate that increasing the magnetic coil current or reducing the volume ratio decreases the travel time and enhances the velocity of the carrier FLM under both DC and PWM magnetic fields. Notably, the FLM exhibits significant capability to transport multiple WLMs, although its average and maximum velocity decrease with each additional WLM. Moreover, the travel time of the marbles varies proportionally with the PWM frequency while exhibiting an inverse relationship with the duty cycle.

The Association Between Surgeon Volume and Dislocation After Total Hip Arthroplasty: A Nationwide Evaluation of 5,106 Orthopaedic Surgeons.

The relationship between surgeon volume and risk of dislocation after total hip arthroplasty (THA) is debated. This study sought to characterize this association and assess patient outcomes using a nationwide patient and surgeon registry. The Premier Healthcare Database was queried for adult primary elective THA patients from January 1, 2016, to December 31, 2019. Annual surgeon volume and 90-day risk of dislocation were modeled using multivariable logistic regression with restricted cubic splines. Bootstrap analysis identified a threshold annual case volume, corresponding to the maximum decrease in dislocation risk. Surgeons with an annual volume greater than the threshold were deemed high volume, and those with an annual volume less than the threshold were low volume. Each surgeon within a given year was treated as a unique entity (surgeon-year unit). 90-day complications of patients treated by high-volume and low-volume surgeons were compared. From 2016 to 2019, 352,131 THAs were performed by 5,106 surgeons. The restricted cubic spline model demonstrated an inverse relationship between risk of dislocation and surgeon volume (threshold: 109 cases per year). A total of 9,967 (87.8%) low-volume surgeon-year units had individual dislocation rates lower than the average of the entire surgeon cohort. Patients treated by high-volume surgeons had decreased risk of dislocation (adjusted odds ratio [aOR], 0.60; 95% CI, 0.54 to 0.67), periprosthetic fracture (aOR, 0.87; 95% CI, 0.76 to 0.99), periprosthetic joint infection (aOR, 0.63; 95% CI, 0.56 to 0.69), readmission (aOR, 0.70; 95% CI, 0.67 to 0.73), and in-hospital death (aOR, 0.60; 95% CI, 0.46 to 0.80). While most of the low-volume surgeons had dislocation rates lower than the cohort average, increasing annual surgeon case volume was associated with a reduction in risk of dislocation after primary elective THA. Level IV.

EXAMINING THE ECO-FRIENDLY ASPECTS OF ETHANOL–METHANOL BLENDED GASOLINE ON ENGINE PERFORMANCE AND EMISSIONS

The increasing global demand for energy, environmental concerns, and the limited availability of energy resources have heightened interest in alternative fuels for internal combustion engines. In this context, internal combustion engines like gasoline engines play a significant role in the search for environmentally friendly and sustainable energy sources. Alcohols are among the most used alternative fuels in spark-ignition engines. This study examines the feasibility of using ethanol and methanol alcohols as fuels simultaneously in a gasoline engine. The research investigates the effects of blending 10% ethanol and 10&amp;#37; methanol alternative fuels with gasoline and using the resulting blended fuel as the engine's fuel source on motor performance and exhaust emissions. The study was conducted under throttle wide-open conditions at different engine speeds. The results revealed a maximum decrease of 1.3&amp;#37; in effective power. Significant reductions in hydrocarbon and nitrogen oxide emissions were observed at all engine speeds, with maximum reductions of 18&amp;#37; and 19&amp;#37;, respectively. Furthermore, a decrease in carbon monoxide emissions is evident across the entire spectrum of engine speeds, underscoring the potential of ethanol-methanol blended gasoline to contribute to a reduced carbon footprint in the transportation sector. As a result of the study, in the case of using ethanol and methanol in engines, both the higher oxygen content of alcohols and their high evaporation energy due to their cooling effect cause an improvement in the emission values emitted from the engine without significant deterioration in engine performance parameters.

Fatigue and fracture performance of sealing ring of hydraulic lifting system of dump truck under different working conditions

Mining dump truck is an important mining equipment. Hydraulic lifting system is important for the working efficiency and safety performance of mining dump truck. Seal ring is the key component in hydraulic lifting system, good sealing performance can better support the work of mining dump truck. ANSYS software was used to establish a finite-element analysis model of the bud-shaped seal, analyse the stress distribution of the seal under the actual working conditions without oil pressure and with oil pressure, and explore the influence of the working parameters such as the fit gap, friction coefficient and oil pressure on the sealing performance of the seal. The results show that the maximum Von-Mises stress and maximum shear stress of the seal increase linearly with the increase of the fit gap, and the maximum contact pressure decreases; when the fit gap is about 0.3 mm, the sealing performance is optimal. Increasing the friction coefficient, the seal contact pressure decreases, resulting in increased wear of the seal; when the friction coefficient is small, it is conducive to improving the sealing performance and reducing the risk of seal breakage. With the increase of oil pressure, the maximum contact pressure of the seal ring basically increases linearly, which is conducive to improving the sealing performance; the maximum Von-Mises stress and the maximum shear stress increase firstly and then remain stable. The orthogonal test method was used to optimise the combination of the structural parameters of the seal, and the optimal combination scheme was obtained; while ensuring the sealing performance, the risk of seal breakage was reduced and the reliability of the seal was improved. The results of the study can provide theoretical guidance for the design and optimisation of the combined bud-shaped seal.

Study of Influence of Various Methods of Intraoperative Keratoprotection in Phacoemulsification of Senile Cataract on Morphological and Functional State of Ocular Surface Structures in Late Postoperative Period

Purpose: to study the effect of various methods of intraoperative keratoprotection in phacoemulsification (PE) of senile cataract (SC) on morphological and functional state of the ocular surface structures (OSS) in the late postoperative period.Patients and methods. 240 patients (240 eyes) who applied for surgical treatment of SC. Age: 65 ± 4 years. 109 men, 131 women. All patients were divided into three observation groups according to the method of intraoperative keratoprotection: 1st group — 60 patients, corneal irrigation with balanced solution; 2nd group — 60 patients, ophthalmic viscosurgical device was applied to the cornea; 3rd group: 3a subgroup — 60 patients, soft contact lens (SCL) was applied to the cornea; subgroup 3b — 60 patients, SCL impregnated with riboflavin solution was applied to the cornea. In addition to the standard ophthalmological examination, Schirmer I test, OCT-scanning were performed, and tear breakup time (TBUT) was determined.Results. The lowest indicator of Schirmer I test was detected in the 1st group a month after the operation. The indicators did not change 2 months after the operation. There were no significant intergroup differences in the final observation period. The TBUT index in all groups decreased. 3 months after the operation, TBUT in the eyes of 3b subgroup was significantly higher in comparison to other groups. The best state of corneal epithelium thickness (CET) occurred in 3a and 3b subgroups. During the epithelium analysis according to OCT-mapping of the cornea, it was noted that the maximum decrease of CET and the number of defects was detected in the 1st and 2nd groups, and the minimum — in 3a and 3b subgroups at all follow-up periods after surgery. There were no significant intergroup differences in preoperative tear osmolarity. 3 months after surgery, tear osmolarity in patients of 3a and 3b subgroups was significantly lower than in patients of the 1st and 2nd groups. OSDI scores in all groups before surgery were comparable. 3 months after the operation, the minimum OSDI values were 3a and 3b in subgroups. Iatrogenic dry eye syndrome (DES) in patients of 3b subgroup was significantly lower than in patients of other groups.Conclusion. In all the studied groups, the standard postoperative dynamics of OSS and TBUT and changes in CET were revealed, with the least variability in 3b subgroup. The use of SCL saturated with riboflavin showed the highest keratoprotective efficacy in PE SC, as it allowed a statistically significant reduction in the incidence of DES in patients after PE in SC (p &lt; 0.05) in comparison with other methods. The developed method for predicting iatrogenic DES in patients after PE in SC is highly informative, because the number of patients in the 1st group with DES was within the expected range of error.

Three-Dimensional Structural Analysis of Sea Temperature During Typhoon Transit

This study uses the Finite-Volume Community Ocean Model (FVCOM) to simulate the hydrodynamic processes during typhoon “Saola”. The simulation results closely match observed data. Typhoon “Saola” was a major system in the Pacific typhoon season, highlighting the complexity and uncertainty of tropical cyclone dynamics. By analyzing historical sea surface temperature data and the typhoon’s trajectory, the three-dimensional response of sea temperature during typhoon “Saola” was explored. The key findings are as follows: 1. Typhoon passage affects both coastal and deep-sea warming and cooling. Temperature changes are more pronounced near the coast, with the highest warming and cooling occurring within five days after the typhoon. In deep-sea areas, the highest warming occurs within five days, while the lowest cooling occurs within two days. 2. The nearshore water layers respond quickly to the typhoon, while the deep-sea water layers primarily respond in the middle depths, with a delayed effect. 3. In coastal shallow waters, the response is intense, with the maximum temperature increase and decrease occurring near the bottom, reaching 5.26 °C and −5.17 °C, respectively. In deep-sea areas, the response is weaker, with the maximum temperature change occurring near the surface: an increase of 0.49 °C and a decrease of −0.98 °C. The deepest response in coastal waters reaches about 80 m, while in the deep-sea area, it only reaches 50 m due to the thicker mixed layer.

The impact of the COVID-19 pandemic on tobacco and alcohol use in the Russian Federation

Introduction. The study is devoted to the analysis of the dynamics of the tobacco and alcohol use prevalence among the adult population during the COVID-19 pandemic.The purpose of the study: to analyze the impact of the COVID-19 pandemic on the prevalence of tobacco and nicotine-containing products consumption among the adult population of the Russian Federation, men and women, as well as different age groups.Materials and methods. The data source for calculations was microdata from the Sample observation of the health status of the population conducted by Rosstat in 2019–2022. The indicators characterizing the prevalence and intensity of tobacco and alcohol use by adults of different age groups, men and women, as well as their relative changes in the pre-covid (2019), covid (2020–2021) and post-covid (2022) periods were calculated by the authors.Results. In 2019–2022, the prevalence of alcohol consumption among the adult population, men and women decreased annually. The largest relative decrease was noted in 2021 and amounted to –5.4% among the adult population, –4.3% among men and –6.1% among women. In 2022, the decline continued and amounted to –1.8%, –0.7% and –2.7%, respectively. In 2021, the maximum decrease in alcohol consumption was detected in the age groups of 15–24 years (–11.0% and –12.2%, respectively), which was replaced by significant growth in 2022. A similar trend was found in relation to the prevalence of tobacco/ nicotine use. During 2020–2021, a decrease in the intensity of alcohol and tobacco use was noted.Conclusion. In general, the COVID-19 pandemic did not affect the general trends in reducing tobacco and alcohol use among the adult population. The changes in the dynamics of their use (decrease) were temporary and were probably related to both health concerns and restrictions imposed during the pandemic period.

Efficacy of Different Doses of Intra-Articular Tranexamic Acid for Reducing Blood Loss and Lower Limb Swelling After Total Knee Arthroplasty: A Prospective, Randomized, Controlled Trial.

Both blood loss and lower extremity swelling after total knee arthroplasty (TKA) can affect a patient's postoperative recovery. The aim of this trial was to investigate whether different doses of intra-articular tranexamic acid (TXA) can reduce blood loss and postoperative lower limb swelling. In a prospective, randomized-controlled trial, a total of 225 patients were randomly assigned to three groups from September 2020 through January 2021: intra-articular injections of 3 g, 1 g of TXA, or placebo (saline solution). The primary outcome indicators were perioperative blood loss and decreased hemoglobin levels. The secondary outcome indicators were lower extremity swelling, functional recovery indicators (hospital for special surgery [HSS] scores, range of motion), visual analog scale [VAS] scores, and transfusion rates and safety outcomes, including thromboembolic events, incidence of wound-related complications, and length of hospital stay. One-way analysis of variance (ANOVA), post hoc Bonferroni correction, Pearson chi-square test and Fisher exact test were used for statistical analysis. Postoperative blood loss was lower in the 1 and 3 g TXA groups (754.00 ± 409.67 mL and 568.70 ± 408.27 mL, respectively) than in the placebo group (977.32 ± 418.69 mL) (p < 0.001). The maximum postoperative decrease in hemoglobin was lower in the 1 and 3 g TXA groups (2.4 ± 0.9 and 1.8 ± 0.9 g/dL, respectively) than in the placebo group (3.1 ± 1.2 g/dL) (p < 0.001). On postoperative Days 1, 2, and 3, the TXA group presented significantly reduced thigh, suprapatellar, and calf swelling and significantly reduced pain scores during exercise. Compared with that in the low-dose group, perioperative blood loss was further reduced in the high-dose TXA group (p = 0.006). However, while patients in the TXA group had improved pain scores, Hospital for Special Surgery scores, and joint range of motion at postoperative rest, these differences were not statistically significant. There were no significant differences in thromboembolic events or complication rates among the three groups. Topical TXA in total knee arthroplasty was effective in reducing postoperative blood loss by 24%-43% and in reducing postoperative lower extremity swelling and pain during exercise. Higher doses (3 g) of TXA further controlled perioperative blood loss without affecting postoperative lower extremity swelling, and there was no increase in the incidence of related complications during follow-up. This study was a single-center, prospective, randomized controlled trial (RCT). The trial was approved by the Clinical Trials and Biomedical Ethics Committee at our institution (number: 2018.676), all participants provided written informed consent, and the trial was prospectively registered in the Chinese Clinical Trial Registry (ChiCTR2000035271).

Study on the influence of guardrails on the mechanical properties of pre-stressed hollow plate beam bridges structure

In order to improve the design level of pre-stressed hollow slab bridge beams, the airport 1# bridge was taken as the research object to study on the influence of guardrails on the mechanical properties of pre-stressed hollow plate beam bridges. On the basis of conducting overall structural verification, a solid model was established to analyze the influence of bridge deck guardrails on the mechanical behavior of cast-in-place joints in hollow slab bridges. Research shows that the maximum deflection and the maximum bending moment internal force decreases by 40 % and 14.5 %, respectively when taking into account the stiffness of the guardrail. However, the maximum shear force of the hollow slab edge joint and middle joint increases by 75 % and 14.5 %, respectively. The maximum shear force increases by 35.62 % when the height of the guardrail increases from 0.5 m to 2 m. The results indicate that the influence of bridge deck guardrails on the shear performance of slab hinge joints should be considered during the preliminary design stage of such bridges. The research results can provide reference for such structures.

Dynamic characteristics of micro-perforated complex beam structures

This paper discusses research concerning the fluctuating dynamic characteristics of various micro-beams featuring intricate designs and perforated surfaces across their entire operational faces. The complex beam structures consist of different types: folded beam, V-shaped beam, and crab-shaped beam with different boundary conditions: fixed-free, fixed-fixed for the simple single beam, and fixed-guided for the rest. The types of holes on the body of the beams are choice in square and circle-shaped for common. In addition, the methodology to determine the dynamic characteristics of the perforated beam is also proposed based on using FEM simulation software. The results show that the dynamic characteristics of the beam in which the holes are distributed depend on the size and shape of perforated holes. As the size or quantity of holes on the surface of the beam in perforated micro-beams grows, the equivalent stiffness drops noticeably. Consequently, the fundamental frequencies of the MEMS systems that include these micro-beams also diminish. The damping coefficient also reduces thanks to the occurrence of these holes. The maximum decrease in damping coefficient reaches 84% in the ideal case for the crab-shaped beam with square holes. These results can be used to optimize the MEMS structures in future research.