Sharp Decrease Research Articles

VP8 Mosaic Nanoparticles Elicit Cross-Neutralizing Immune Responses and Provide Protection Against Heterotypic Rotavirus Challenge in Mice.

Group A rotaviruses (RVA) remain one of the dominant pathogens causing diarrhea in children under 5 years of age worldwide, despite a sharp decrease of RVA-associated diarrhea and mortality since the introduction of rotavirus vaccines. The decreased effectiveness of live attenuated rotavirus vaccines, coupled with the emergence of new rotavirus genotypes and the risk of cross-species virus transmission, underscores the necessity to develop more effective and broad-spectrum rotavirus vaccines. In this study, we utilized nanoparticles coupled with the SpyCatcher-SpyTag system to effectively display the truncated VP8-1 protein. The modular display of the monovalent VP8-1 proteins markedly increased the immunogenicity of VP8-1. Furthermore, the bivalent display of VP8-1 proteins from simian rotavirus SA11 and lamb rotavirus LLR on the same particle not only increased immunogenicity against homotypic antigens but also elicited robust heterotypic immune responses and conferred effective protection against a distant heterotypic rotavirus with sequence identities of only 62%-66% in an adult mouse model. Therefore, mosaic VP8 nanoparticles could be considered as a viable strategy for the development of the next-generation broad-spectrum rotavirus vaccine.

An innovative approach to study the influence of microstructure on thermal shock resistance of porous ceramics

AbstractPorosity is a critical microstructural factor in ceramic materials, influencing their mechanical and thermal properties. However, the detailed mechanisms through which porosity, grain size, and grain boundary fracture energy affect the thermal shock resistance of porous ceramics are still not fully understood. This study introduces a dual‐scale model that integrates these microstructural parameters to predict fracture toughness and thermal shock resistance. Using the single‐edge V‐notch fracture toughness testing principle, we calculate the thermal stress intensity factor and establish its relationship with temperature differentials. The critical temperature differential, which marks the onset of thermal shock damage, is determined when the thermal stress intensity factor reaches the fracture toughness threshold. The model reveals a significant interplay between porosity, grain size, and grain boundary fracture energy, with fine‐grained ceramics (grain size < 10 µm) showing a sharp decrease in fracture toughness as porosity increases, while coarser‐grained ceramics are less affected by porosity. These findings provide a deeper understanding of the microstructural optimization needed to enhance the thermal shock resistance of high‐performance porous ceramics.

Successful NH3 abatement policies and regulations in German agriculture

Anthropogenic ammonia (NH3) emissions, of which about 95 % are from agriculture, have led to environmental pollution, resulting in tremendous damage to human health and ecosystems. Thus, the NEC Directive 2016/2284/EU sets national reduction targets for NH3 emissions in individual EU countries. To implement the NEC Directive for NH3 emission targets, Germany amended the Fertilizer Application Ordinance in 2017 and 2020 (DüV_amended) and set the air pollution control regulation, Technical Instructions on Air Quality Control (TA_Luft). This study aimed to evaluate the impact of the DüV_amended on NH3 mitigation from applying livestock manure, digestates, synthetic nitrogen (N) fertilizers, and TA_Luft on housing and storage. This study showed that Germany reached the first national NH3 reduction target in 2020, as set by the NEC directive. The German DüV_amended, a significant policy change, has profoundly impacted NH3 emission mitigation from agriculture after 2017 by implementing measures aimed directly at NH3 reduction, reducing N surpluses, and improving N use efficiency. The reduction in NH3 emissions from synthetic N fertilizers between 2016 and 2022 contributed about 51 % to the decrease from the agricultural sector over the same period. Among the synthetic fertilizers, NH3 reduction from urea between 2016 and 2022 accounted for around 83 % of the total reduction from synthetic N, indicating that the NH3 emissions from urea fertilizer by reducing urea application and mandating urea to be incorporated immediately or to be stabilized with urease inhibitors played a crucial role in the sharp decrease in NH3 emissions over the last years in Germany. Achieving a high yield by lowering the synthetic N rate in this study strongly suggests that optimal reduction in N rate does not necessarily result in yield losses but rather in a pivotal relationship between the agronomic and environmental performance and indicates that the DüV_amended was an effective measure that can reduce the NH3 emissions.Over 80 % of Germany's annual agricultural NH3 emissions in 2021 and 2022 originated from livestock and digestates from energy crops. Mandatory close to the soil band application of slurry and digestates on cultivated cropland since 2020 reduced NH3 emissions. In addition, banning of broadcast application of slurry to grassland and manure incorporation within one hour on uncultivated soils will become mandatory in 2025 to comply with NEC 2030´s target of 29 % NH3 reduction relative to 2005. The recent German air pollution control regulation (TA_Luft) enforces abatement measures such as air purifiers in large poultry and pig housings and covered storage of slurry and digestate storages of large farms. The results of the German NH3 abatement strategy for synthetic N fertilizers may help reduce NH3 emissions worldwide, especially for countries consuming high amounts of urea fertilizers.

Ortholog of autism candidate gene RBM27 regulates mitoribosomal assembly factor MALS-1 to protect against mitochondrial dysfunction and axon degeneration during neurodevelopment.

Mitochondrial dysfunction is thought to be a key component of neurodevelopmental disorders such as autism, intellectual disability, and attention-deficit hyperactivity disorder (ADHD). However, little is known about the molecular mechanisms that protect against mitochondrial dysfunction during neurodevelopment. Here, we address this question through the investigation of rbm-26, the Caenorhabditis elegans ortholog of the RBM27 autism candidate gene, which encodes an RNA-binding protein whose role in neurons is unknown. We report that RBM-26 (RBM26/27) protects against axonal defects by negatively regulating expression of the MALS-1 (MALSU1) mitoribosomal assembly factor. Autism-associated missense variants in RBM-26 cause a sharp decrease in RBM-26 protein expression along with defects in axon overlap and axon degeneration that occurs during larval development. Using a biochemical screen, we identified the mRNA for the MALS-1 mitoribosomal assembly factor as a binding partner for RBM-26. Loss of RBM-26 function causes a dramatic overexpression of mals-1 mRNA and MALS-1 protein. Moreover, genetic analysis indicates that this overexpression of MALS-1 is responsible for the mitochondrial and axon degeneration defects in rbm-26 mutants. These observations reveal a mechanism that regulates expression of a mitoribosomal assembly factor to protect against axon degeneration during neurodevelopment.

Dust event identification and characterization with one-year online observations in Beijing.

Dust storms have a profound impact on air quality, atmospheric chemistry, and human well-being by carrying vast amounts of particles over distances of thousands of kilometers. However, the overall characteristics of these dust events and their influence on secondary pollution in the northern China region are not yet well understood, due to a lack of long-term, comprehensive observations and objective identification techniques. Based on principal component analysis combined with high-time-resolution observations of particulate matter components, here we developed a robust method to identify dust storm events and identified 14 dust events in Beijing in 2019. We further classified these 14 events into two distinct types using Lagrangian particle dispersion models and backward trajectory analysis. The first type (Type I, 9 cases) is characterized by synoptic patterns in Mongolia, originating from the north and directly impacting the Beijing area. The second type (Type II, 5 cases) involves air masses from the north or northwest that temporarily pass through polluted regions south of Beijing before being carried back into the city. Consistently, during Type I dust events, we observed a sharp decrease in secondary inorganic aerosols (SIA) from 65 % to 7 %, as well as in the sulfur oxidation ratio (SOR) and nitrogen oxidation ratio (NOR) (from 0.52 to 0.19, and 0.27 to 0.018 respectively). In contrast, during Type II dust events, SIA concentrations increased by 91 %, along with an increase in SOR (1.7 %), NOR (69 %), and f44/f43 (3.0 %), suggesting an enhancement of secondary aerosol formation resulting from the interaction between dust aerosols and gaseous anthropogenic pollutants. Our results demonstrate that dust events and the sub-type of dust events can be identified in an objective manner using the protocol developed in this study and the dynamics should be considered when discussing impacts of dust events on atmospheric chemistry.

Guandong-candy-inspired electrolessly welded composite polyvinylidene fluoride (PVDF) membranes with self-cleaning and recyclable properties for efficient oil-in-water emulsion separation

Recently, oily wastewater has become an urgent cross-regional problem. Membrane technology is considered a sound solution to this crisis. However, membrane fouling causes a sharp decrease in water permeance and service life, which greatly restricts membrane applications. In addition to a few degradable materials, the most severely polluted membranes are burned or buried in the soil, wasting resources and accelerating ecological damage. Inspired by Guandong candy, we reported a novel, facile, and green approach to construct composite polyvinylidene fluoride (PVDF) membranes with stable self-cleaning, anti-oil-fouling, and photocatalytic recovery properties for efficient oil-in-water emulsions separation. Due to the synergistic effect of the superhydrophilic tin dioxide/titanate nanotubes (SnO2/TNTs) and Guandong-candy-inspired electrolessly welding organic–inorganic hybrid colloids, the composite PVDF membrane showed remarkable stability and underwater oil-repellency properties. Accordingly, the composite PVDF membrane achieved excellent water permeance (>2600 L m−2 h−1 bar−1), superior separation efficiency (>99.6 %), and long-term antifouling performance during soybean oil-in-water emulsion separation. More importantly, the composite PVDF membrane exhibited highly efficient self-cleaning and recovery of the PVDF membrane and SnO2/TNTs under visible-light irradiation. Within the framework of green and sustainable concepts, this is a novel reusable idea for the recyclable utilization of commercial PVDF membranes and photocatalytic minerals in oily wastewater purification.

Nutrient limitation shortly before harvest promotes high accumulation of antioxidants in lettuce

AbstractPlants exposed to drought not only have to cope with a shortage of water, but also with a simultaneous decrease in nutrient availability. In this greenhouse experiment, the responses of antioxidants and key metabolites to 2 or 4 days of water limitation immediately prior to harvest were compared to the effect of nutrient limitation with continued water supply in lettuce leaves. Water limitation led to a faster increase in stress intensity than nutrient limitation. While moderate drought stress led to a slight increase in the antioxidant compounds studied, there was a concomitant sharp decrease in starch content. Under nutrient limitation, an increase in the content of ascorbic acid, the proportion of reduced ascorbic acid and the content of phenolic compounds, flavonoids, soluble sugars and starch was observed in the mild phase of stress. These results suggest that reducing nutrient availability shortly before harvest could be a suitable means of improving the nutritional value of crops through cultivation practices as opposed to breeding.

The impact of the tobacco law on tobacco-related hospitalizations in Portugal - a natural experiment

Abstract Introduction Tobacco is responsible for approximately 8 million deaths annually worldwide, with 1.2 million resulting from passive exposure to smoke, as reported by the WHO. Comprehensive tobacco control policies have been enacted across Europe, yet their impacts are seldom assessed. This study evaluates the effects of the anti-tobacco legislation enacted in Portugal in 2007 on tobacco-related hospitalizations between 2002 and 2018. Methods Data from all in-patient admissions in public hospitals throughout the 2002-2018 period were utilized. A quasi-experimental interrupted time series design was employed, treating 2008 as an exogenous shock. The dependent variables include the municipality-based incidence of hospitalizations by year for tobacco-related diseases, namely, Acute Myocardial Infarction, stroke, lower respiratory tract infections, chronic obstructive pulmonary disease, and asthma. The analysis was adjusted for the percentage of women, the percentage of individuals aged over 65, and purchasing power in the municipality. Time trend graphs for each variable were generated, followed by an adjustment using the Poisson regression model to forecast their trends. A comparison was conducted between observed post-law implementation data and projected values from the regression model to ascertain the percentage difference between the two. Expected Results The 2007 tobacco law led to significant reductions in tobacco-related disease incidence, with the most notable effects immediately post-implementation. The impact varies across age groups, with younger individuals (30-49 years) showing a sharper decrease. The effect diminished over time, as indicated by negative coefficients in time:law interactions, such as -0.03. Conclusions The anti-tobacco laws implemented in Portugal have effectively decreased hospitalizations related to tobacco use, suggesting potential increases in life expectancy and reduction in health system burden. Key messages • Public health policies are crucial for the long-term improvement of people’s health. • Non-exposure to tobacco can bring health gains on several levels.

Prescription of antibiotics for urinary tract infections in outpatient care in Bavaria: An analysis of routine data.

Patients with urinary tract infection (UTI) in German outpatient care are usually treated by general practitioners (GPs), as well as by other specialties. To prevent antibiotic resistances and side effects, German guidelines recommend fosfomycin, nitrofurantoin, pivmecillinam and nitroxoline as first-line treatments, and advice against broad-spectrum antibiotics such as fluoroquinolones and cephalosporins. However, data from the European Centre for Disease Prevention and Control indicates a significant proportion of second-line antibiotics in German outpatient care. Our aim was to analyze whether antibiotic prescription has changed over time in accordance with guidelines. In addition, we aimed to investigate whether specialties prescribe different antibiotics for UTIs and whether prescription varies according to patient age and sex. For patients receiving more than one antibiotic, we wanted to determine whether subsequent prescriptions show a change in substances and specialties involved. This retrospective study involved routine data (2013 to 2019) provided by the Bavarian Association of Statutory Health Insurance Physicians. Data on diagnoses and prescriptions were transmitted from outpatient care physicians on a quarterly basis. UTI patients ≥12 years were included. We analyzed 1.7 million UTI prescription cases. In females, shares of fluoroquinolones decreased sharply over time, while shares of first-line substances fosfomycin and pivmecillinam increased. Gynecologists showed the highest shares of first-line substances compared to GPs and urologists. Fluoroquinolone shares decreased in all three specialty groups. In females, older patients showed lower shares of first-line substances than younger patients. If a second or third antibiotic was prescribed, fosfomycin shares decreased, while shares of nitrofurantoin, nitroxoline and cephalosporins increased. Our findings show a trend towards a more guideline-adherent prescribing in the treatment of UTI, with a significant increase of shares of fosfomycin and pivmecillinam, especially in women, and a sharp decrease of shares of fluoroquinolones.

Ab initio molecular dynamics simulation reveals the influence of entropy effect on Co@BEA zeolite-catalyzed dehydrogenation of ethane

The C–H bond activation in alkane dehydrogenation reactions is a key step in determining the reaction rate. To understand the impact of entropy, we performed ab initio static and molecular dynamics free energy simulations of ethane dehydrogenation over Co@BEA zeolite at different temperatures. AIMD simulations showed that a sharp decrease in free energy barrier as temperature increased. Our analysis of the temperature dependence of activation free energies uncovered an unusual entropic effect accompanying the reaction. The unique spatial structures around the Co active site at different temperatures influenced both the extent of charge transfer in the transition state and the arrangement of 3d orbital energy levels. We provided explanations consistent with the principles of thermodynamics and statistical physics. The insights gained at the atomic level have offered a fresh interpretation of the intricate long-range interplay between local chemical reactions and extensive chemical environments.

The formation and ventilation of an oxygen minimum zone in a simple model for latitudinally alternating zonal jets

Abstract. An advection–diffusion model coupled to a simple dynamical ocean model is used to illustrate the formation and ventilation of an oxygen minimum zone. The advection–diffusion model carries a passive tracer with a source at the western boundary and a Newtonian damping term to mimic oxygen consumption. The dynamical model is a non-linear one-and-a-half-layer reduced-gravity model. The latter is forced by an annually oscillating mass flux confined to the near-equatorial band that, in turn, leads to the generation of mesoscale eddies and latitudinally alternating zonal jets at higher latitudes. The model uses North Atlantic geometry and develops a tracer minimum zone remarkably similar in location to the observed oxygen minimum zone in the eastern tropical North Atlantic (ETNA). This is despite the absence of wind forcing for a subtropical gyre and the shadow zone predicted by the ventilated thermocline theory. Although the model is forced only at the annual period, the model nevertheless exhibits decadal and multidecadal variability in its spun-up state. The associated trends are comparable to observed trends in oxygen within the ETNA oxygen minimum zone. Notable exceptions are the multi-decadal decrease in oxygen in the lower-oxygen minimum zone and the sharp decrease in oxygen in the upper-oxygen minimum zone between 2006 and 2013.

Part-load performance analysis of a modular biomass boiler with a combined heat and power industrial Rankine cycle and supplementary sCO2 Brayton cycle

Abstract The addition of a supplementary high efficiency cycle integrated with an existing steam power cycle may increase energy efficiency and net generation. In this paper, part load performance and operation of a modular biomass boiler with an existing industrial Rankine steam heat and power cycle and supplementary supercritical CO2 (sCO2) Brayton cycle is analysed. The aim is to leverage the high efficiency of the sCO2 cycle by retrofitting sCO2 heaters in the existing biomass boiler, increasing net power output and thermal efficiency. With nominal load performance previously investigated, understanding part-load performance and operation is vital to determine cycle feasibility. A quasi-steady-state one dimensional thermofluid network model was used to simulate the integrated cycle performance for loads ranging from 100% to 60%. The model solves the mass, energy, momentum, and species balance equations, capturing detailed component characteristics. Two control methodologies are explored for the sCO2 Brayton cycle, namely inventory control and inventory control combined with throttling valve control. Inventory control is selected as the better performing control strategy for load following, maintaining high thermal efficiency across partial loads. At 60% load, the sCO2 compressor operates near the pseudo-critical point, leading to a sharp decrease in sCO2 cycle capacity, which requires careful management of inventory control. Two sCO2 heater configurations are investigated, namely a single convective-dominant heater, and a dual heater configuration with a radiative and a convective heater. The single heater configuration is preferred to minimise adverse impacts on the Rankine cycle superheaters.

Mathematical model of molten iron and slag flow in the hearth

The stable hearth discharge is crucial for the operation of a blast furnace (BF). This study established a mathematical model for hearth discharge based on Bernoulli's principle, which considers the blast pressure, kinetic energy of molten iron and slag, gravitational potential energy, the pressure loss of molten iron and slag flowing through the deadman and taphole. It is found that the sharp increase of molten iron and slag flow is probably due to the fracture of the mud, while the sharp decrease of molten iron and slag flow is probably due to the blockage of the taphole by coke. This paper also studies the effect of operating parameters on the hearth discharge. With the increase of taphole plug time, the production rate and slag viscosity, the tap-end time will increase. With the increase of deadman voidage, the tap-end time will be shortened. The correctness of the mathematical model was verified by the actual flow rate of slag and molten iron.

Effects of Ca contents on microstructures and mechanical properties of friction stir processed Mg alloys

Ca alloying is beneficial for improving the uniform elongation for friction stir processed (FSPed) Mg-4Al-2Sn-xCa (0, 0.5, 1.0 and 1.5 wt.%) (AT42-xCa) alloys. Coarse CaMgSn and Al2Ca particles in as-cast AT42-xCa alloys lead to a sharp decrease in elongation. Friction stir processing (FSP) is effective in improving strength and elongation by refining grain structure along with CaMgSn and Al2Ca particles, and inducing grain orientations with high Schmid factors for basal slip. Consequently, FSPed AT42-0.5Ca alloy exhibits simultaneously enhanced ultimate tensile strength (∼224 MPa) and elongation (∼30.9%). Compared to the Ca-free alloy, 0.5 wt.% Ca alloying increases the heat input and promotes the dislocation recovery, reducing residual dislocations. Nano-sized CaMgSn precipitates in grain interiors inhibit the dynamic recovery of dislocations during tensile, facilitating the work-hardening ability. Besides, high Schmid factors facilitate basal dislocation slips. Therefore, high EL is primarily due to the dislocation-free fine grain (∼2.7 μm), refined CaMgSn particles (micron-sized particles (∼1.3 μm) and nano-sized precipitates (∼55 nm)) and high Schmid factors (∼0.446) for basal slips.

The blood leukocytes and platelets of little ground squirrels (<i>Spermophilus pygmaeus</i> Pall.) during hibernation and arousal

During hibernation, mammals periodically go through cold (torpor) and warm (awakening) phases. Previously, a sharp decrease in the levels of leukocytes and blood platelets in the torpid state was found, but the dynamics of their changes during arousal remains unknown. We have studied the content and composition of the circulating cells of the little ground squirrel during arousal. The number of all types of leukocytes and platelets in the torpid state is significantly reduced. Restoration of the level of leukocytes in the blood during arousal occurs in two phases: fast (Tb 10—20°C) and slow (Tb 20—37°C). Unlike other cell types, the content of neutrophils remains below euthermal condition after body temperature recovery. During arousal in the Tb range of 10—30°C, the level of platelets increases linearly, while the normalization of the P-LCR parameter does not occur.

Decoupling Sources of Anthropogenic Influences on Sediments of the Visovac Lake (Krka National Park, Croatia) Using Multiparametric Approach.

Historical changes of sediment characteristics and levels of inorganic and organic contaminants were studied in dated sediment cores from the Visovac Lake, situated in the Krka National Park, Croatia, to identify the main sources of anthropogenic pressures on this highly protected system. Depth distributions of lithogenic elements showed a steady decrease of terrigenous inputs due to the reduction in agricultural activities in the area, which was particularly pronounced during the 1991-1995 war in Croatia. Vertical and longitudinal distributions of Cd and Zn indicated that they are predominately of anthropogenic origin. The historical profiles of these toxic metals coincide well with the recorded production of metal industry in the upper reach of the Krka River with a sharp decrease reflecting the interruption by the war and slow recovery afterwards. By contrast, the recovery of the tourist industry in Krka NP after the war was accompanied by increasing contamination by elements characteristic of boat and car traffic (Sn, Cu, Pb) as well as oil pollution. The contamination with polycyclic aromatic hydrocarbons and polychlorinated biphenyls was only moderate. Although levels of metallic and organic contamination can be considered relatively low, the observed shift from industrial to tourism-related sources indicated that touristic activities should also be regarded as a possible threat for this vulnerable karst aquatic ecosystem.

Trusted microelectronics: reverse engineering chip die using U-Net convolutional network

In the field of integrated circuits (IC) reverse engineering, accurate IC die image segmentation is critical for ensuring trust and detecting counterfeits. This study introduces a deep learning-based methodology utilizing a U-Net Convolutional Neural Network (CNN) tailored for IC image segmentation. Our model excels in processing complex IC images with noise, achieving superior segmentation accuracy. The model was evaluated on a dataset of 512 × 512 pixel IC die images, achieving a mean Intersection over Union (IoU) of 81.2%, which is a significant improvement over traditional image processing techniques that achieve an IoU around 65.3%. During training, the model’s Dice Loss showed a sharp decrease, as depicted in the provided graph, highlighting the model’s ability to effectively learn and refine segmentation boundaries. Simultaneously, the training accuracy, as illustrated in the accompanying accuracy graph, improved steadily, reaching approximately 60% but still rising. This convergence of Dice Loss and the upward trend in accuracy demonstrate the model’s robust performance across varying noise levels and its effectiveness in producing precise segmentation outputs. This work underscores the effectiveness of CNNs, particularly the U-Net architecture, in enhancing the accuracy and reliability of IC die image analysis, paving the way for improved IC manufacturing quality assurance.

Characterization of Microstructure of Fe-TiC and Fe-B4C Composites Using Ultrasonic Measurements

In this paper, an iron (Fe) matrix reinforced with boron carbide (B4C) and titanium carbide (TiC) was produced by conventional furnace sintering at the same compositions and temperatures. Experimental data on the change in ultrasonic velocity parameter, densities and porosity of these two different microstructure composites during microstructure development are reported. The microstructural phases were characterized by metallographic studies and hardness measurements. The velocities of ultrasonic longitudinal waves were measured by the pulse- echo method using the transmit/receive probe. In the Fe-TiC composite sample, ultrasound longitudinal wave velocity, hardness and porosity increased linearly depending on the increasing amount of TiC. In the Fe-B4C composite sample, on the other hand, there is a linear increase in general depending on the increasing amount of B4C, and there is a sharp decrease in the amount of 8,33% B4C. The reason for this decrease and other results are explained by taking into account SEM and XRD analyzes.

The Effectiveness of Dry Carbon Dioxide Baths in Menopausal Syndrome: a Randomized Clinical Study

INTRODUCTION. Climacteric syndrome is characterized by significant disorders in the nervous, musculoskeletal, urinary and cardiovascular systems in women of the perimenopausal and postmenopausal periods. The main reason is a sharp decrease in estrogen levels. Menopausal hormone therapy is often used for treatment, but due to contraindications and complications, it does not always completely solve the problem. This has sparked interest in alternative treatments such as dry carbon dioxide baths. AIM. To study the effectiveness of using dry carbon dioxide baths in women with menopausal syndrome and evaluate their impact on the neurovegetative, metabolic and psycho-emotional state of these patients. MATERIALS AND METHODS. A prospective randomized study was conducted involving 70 patients with moderate climacteric syndrome aged from 48 to 60 years. Using a simple randomization method, the women were divided into 2 groups: 35 patients of the main group received 10 procedures of dry carbon dioxide baths with a CO2 concentration of 15–20 %, temperature 28–32 °C, lasting 15–20 minutes, 35 patients of the control group did not receive any treatment. To assess the effectiveness of treatment, a modified Kupperman-Uvarova menopausal index, an assessment of the effect of “hot flashes” on daily life on the HFRDIS scale, as well as daily blood pressure monitoring (SMAD) were used. RESULTS AND DISCUSSION. After treatment, patients in the main group observed a significantly significant (p 0.05) improvement in the patients’ condition in the form of a decrease in integral indicators of the modified menopausal index and an assessment of the impact of hot flashes on daily activity on the HFRDIS scale by 28.2 and 43.1 %, respectively, as well as in the form of a decrease in average daily systolic blood pressure by 13.7 %. CONCLUSION. The use of dry carbon dioxide baths is recommended for use in women with moderate climacteric syndrome, since this method significantly improves the quality of life of patients and is an effective non-drug that can reduce the drug load on the body of a woman suffering from neurovegetative disorders.

Effect of SF6 circuit breaker parameters on switching overvoltages evaluated based on nominal modes of converter transformers

In this work, we set out to investigate the influence of operating currents of SF6 circuit breakers on the magnitude of overvoltages during switching of converter transformers. The experience of electrical equipment operation is analyzed with a focus on the problems associated with the natural aging of insulation, overloads, and switching overvoltages. The methods of equipment diagnostics were used. According to statistical data, at present, about 37% of short circuits between phases and 42% of single-phase earth faults in electrical networks of industrial enterprises occur due to switching overvoltages. The conducted tests showed that the overvoltages emerging during switching by SF6 circuit breakers of converter transformers, which are used in aluminum smelters, may reach a three-fold rated voltage of the network. This threatens the insulation of transformer windings, cable line, and the switch itself. It was established that an increase in operating currents of an LF2 circuit breaker, not exceeding 27.8% of the rated current of the switch, leads to an increase in overvoltages during switching of converter transformers. At a further increase in the operating currents of the circuit breaker by more than 27.8% of the rated current of the circuit breaker, a sharp decrease in the value of switching overvoltages is observed. Therefore, the operating currents of SF6 circuit breakers were established to affect the level of switching overvoltages of converter transformers. The underlying mechanism of this phenomenon was determined, which should be taken into account when improving the reliability of power supply of converter transformers and, consequently, the reliability of aluminum production. The feasibly of resistive-capacitive dampers as the most effective means for limiting overvoltages during switching of converter transformers was confirmed.