Maximum Increase Research Articles

How the window of visibility varies around polar angle.

Contrast sensitivity, the amount of contrast required to discriminate an object, depends on spatial frequency (SF). The contrast sensitivity function (CSF) peaks at intermediate SFs and drops at other SFs. The CSF varies from foveal to peripheral vision, but only a couple of studies have assessed how the CSF changes with polar angle of the visual field. For many visual dimensions, sensitivity is better along the horizontal than the vertical meridian and at the lower than the upper vertical meridian, yielding polar angle asymmetries. Here, for the first time, to our knowledge, we investigate CSF attributes around polar angle at both group and individual levels and examine the relations in CSFs across locations and individual observers. To do so, we used hierarchical Bayesian modeling, which enables precise estimation of CSF parameters. At the group level, maximum contrast sensitivity and the SF at which the sensitivity peaks are higher at the horizontal than vertical meridian and at the lower than the upper vertical meridian. By analyzing the covariance across observers (n = 28), we found that, at the individual level, CSF attributes (e.g., maximum sensitivity) across locations are highly correlated. This correlation indicates that, although the CSFs differ across locations, the CSF at one location is predictive of that at another location. Within each location, the CSF attributes covary, indicating that CSFs across individuals vary in a consistent manner (e.g., as maximum sensitivity increases, so does the corresponding SF), but more so at the horizontal than the vertical meridian locations. These results show similarities and uncover some critical polar angle differences across locations and individuals, suggesting that the CSF should not be generalized across isoeccentric locations around the visual field.

Rigid-Flexible Coupled Dendritic Molecule Doping: General Approach to Activate Commercial Polymers into Harsh Condition-Tolerant Multi-Reusable Strong Supramolecular Adhesives.

Developing functional adhesives combining strong adhesion, good recyclability and diverse harsh-condition adaptability is a grand challenge. Here, we introduce a general dendritic molecule doping strategy to activate commercial polymers into a new family of supramolecular adhesives integrating high adhesion strength, ultralow temperature, water resistant and multi-reusable properties. Our method involves rational design of a new rigid-flexible coupled dendritic molecule-M4C8OH as a versatile dopant, while simple M4C8OH doping into commercial polymers can modulate internal and external non-covalent interaction to enable H-bonding enhanced interchain cross-linking for tough cohesion along with enhanced interphase interaction. This endows 20 wt % M4C8OH-doped polycaprolactone (PCL) adhesives (PCL-M4C8OH) with improved adhesion strength on various substrates with the maximum increase up to 2.87 times that of PCL. In particular, the adhesion strengths of PCL-M4C8OH on polymethyl methacrylate at 25 °C and -196 °C reach 4.67 and 3.58 MPa-1.9 and 2.3 times those of PCL and superior to diverse commercial adhesives and most reported adhesives. PCL-M4C8OH also displays markedly-improved multi-usability and tolerance against ultralow temperature and diverse wet environments. Mechanism studies reveal the crucial role of M4C8OH molecular structures toward superior adhesion. Our method can be expanded to other polymer matrices, yielding diverse new supramolecular adhesives.

SeFi-CD: A Semantic First Change Detection Paradigm That Can Detect Any Change You Want

The existing change detection (CD) methods can be summarized as the visual-first change detection (ViFi-CD) paradigm, which first extracts change features from visual differences and then assigns them specific semantic information. However, CD is essentially dependent on change regions of interest (CRoIs), meaning that the CD results are directly determined by the semantics changes in interest, making its primary image factor semantic of interest rather than visual. The ViFi-CD paradigm can only assign specific semantics of interest to specific change features extracted from visual differences, leading to the inevitable omission of potential CRoIs and the inability to adapt to different CRoI CD tasks. In other words, changes in other CRoIs cannot be detected by the ViFi-CD method without retraining the model or significantly modifying the method. This paper introduces a new CD paradigm, the semantic-first CD (SeFi-CD) paradigm. The core idea of SeFi-CD is to first perceive the dynamic semantics of interest and then visually search for change features related to the semantics. Based on the SeFi-CD paradigm, we designed Anything You Want Change Detection (AUWCD). Experiments on public datasets demonstrate that the AUWCD outperforms the current state-of-the-art CD methods, achieving an average F1 score 5.01% higher than that of these advanced supervised baselines on the SECOND dataset, with a maximum increase of 13.17%. The proposed SeFi-CD offers a novel CD perspective and approach.

Variation of magnetic properties by heat treatment of dispersed oriented sheets using plate-shaped strontium ferrite particles

Abstract Plate-shaped hexagonal SrFe12O19 particles synthesized using the molten salt method were dispersed in a resin, and oriented sheets were prepared by coating the dispersion onto quartz substrates. The oriented sheets on quartz substrates were heat treated at 300–900 ℃. The variations in the coercive force and squareness of the oriented sheets before and after heat treatment were examined. The coercive force remarkably increased with increasing heat treatment temperature, exhibiting a maximum increase rate of approximately 16 % in the heat treatment at 800 ℃. The increase in coercive force suggests a reduced effect of shape anisotropy due to the stacking of the plate surfaces, caused by the removal of resin between the particles; this highlights the influence of crystalline anisotropy.

Studying the Constitutive Model of Damage for a Stainless Steel Argon–Oxygen Decarburization Slag Mixture

The purpose of this study was to fully explore the mechanical properties of five different doses of an Argon–Oxygen Decarburization slag mixture in an unconfined compressive strength test. The peak stress, elastic modulus, and stress–strain curve of the mixture were studied for 90 days. Based on the experimental data and according to the theory of damage mechanics, the concept of damage threshold (t) was introduced to construct a damage constitutive model. Referring to the damage threshold of concrete, that of the mixture was determined to be 0.7 times higher than the peak strain, and the correlation coefficient between the established model and the test curve was above 0.85. These results indicate that the addition of AOD slag and fly ash can cause hydration reactions, increase the quantity of hydration products, and enhance the peak stress and elastic modulus of the mixture. The maximum increases were 94.9% and 43.1%, respectively. Parameters a and b reflect the peak stress and brittleness of the mixture, respectively. The incorporation of Argon–Oxygen Decarburization slag can make the mixture less brittle and improve its properties. The incorporation of Argon–Oxygen Decarburization slag can protect the mixture from damage. The maximum decrease is 40.2%.

Three-dimensional elastic Rayleigh–Taylor instability at the cylindrical interface

This paper presents a linear analysis of elastic Rayleigh–Taylor instability at both cylindrical column and cylindrical shell interfaces. By considering the rotational part of the disturbance flow field, an exact solution is derived, revealing that the most unstable mode is two-dimensional in the cross section. As the column radius decreases, the maximum growth rate increases, while the corresponding azimuthal wave number decreases incrementally until it reaches 1. Thinning the cylindrical shell is found to be a destabilizing effect, leading to an increase in both the cutoff wave number and the most unstable azimuthal wave number. The maximum growth rate usually increases as the shell becomes thinner, except in cases with small radii where feedthrough effects occur. For thin shells with small radii, the cutoff axial wave number is determined by the radius rather than the shell thickness. Comparisons between the growth rates derived from the potential flow theory and the exact solution show significant discrepancies in cylindrical shells, mainly due to substantial deviations in the cutoff wave number.

Dynamic responses of non-isolated and isolated liquid storage tanks under mainshock-aftershock sequences

After the mainshock earthquake, aftershocks often occur frequently, and the destructive effect of aftershocks on structures cannot be ignored. Based on the potential flow theory, the mechanical behavior of liquid is simulated. Considering liquid-solid coupling, material nonlinearity, and liquid sloshing, a three-dimensional numerical calculation model of liquid storage tank is established. No pulse-like and pulse-like mainshock-aftershock sequences are selected, and the seismic responses of non-isolated and isolated liquid storage tanks is compared and studied. The results show that the mainshock-aftershock sequence has a significant impact on the dynamic responses of the liquid storage tank, and the maximum increase rate reaches to 195.4 %. The effect of the mainshock-aftershock sequence on the dynamic responses of non-isolated liquid storage tanks is greater than on the dynamic response of isolated liquid storage tanks. Compared with the pulse-like mainshock-aftershock sequences, the no pulse-like mainshock-aftershock sequences generally have a greater impact on the dynamic responses of the liquid storage tanks. Overall, isolation significantly reduce the impact of mainshock-aftershock sequences on the dynamic responses of liquid storage tanks, and effectively enhance the seismic performance of liquid storage tanks under mainshock-aftershock sequences.

Effects of speech tracking method using hearing aids for hearing disorder in older people.

Speech tracking is defined as a complex act or task of listening in which the learner tracks the speech heard and repeats it as accurately as possible while paying attention to incoming contextual information. This ability involves auditory input, speech output, repetition, and divided attention. In this small-scale study, we aimed to use a speech-tracking method to train older adults with hearing loss and examine its effects on hearing loss from multiple perspectives, including hearing handicap, frailty, and neuropsychological testing. Auditory rehabilitation was provided to older patients who purchased hearing aids at the clinic and wanted to engage in rehabilitation. The Hearing Handicap Inventory for the Elderly, Nursing Home Hearing Handicap Index, speech-tracking rate, Token Test, Communication Activities of Daily Living, Kihon Checklist, Mini-Mental State Examination, Digit Symbol Substitution Test, symbol search, and word recall were used for assessments before and after rehabilitation using the speech-tracking method. Changes in scores of each assessment item and sub-item were examined using Wilcoxon's signed-rank test, and changes per question were examined using the sign test. The speech tracking rate (p<0.001), Token Test score (p<0.001), and Mini-Mental State Examination score (p=0.035) improved significantly after the training. Notably, the speech-tracking rate improved for 31 of the 33 participants, with a maximum increase of 19.6 phrases per minute. The combination of a hearing aid and the speech-tracking method improved auditory comprehension.

A New Method for Compression Testing of Reinforced Polymers

Compressive testing of specimens taken from relatively thin composite plates is difficult, especially due to the occurrence of buckling. To prevent buckling, the central portion of the specimens used for the compression test has smaller dimensions, and the specimens can be guided along their entire length. For these reasons, optical methods, such as digital image correlation (DIC), cannot be used for the compression test and strain rosettes cannot be glued onto the samples to determine Poisson’s ratio. In this study, compression tests of a glass fiber-reinforced polymer (GFRP) were conducted using both the ASTM D695 (Boeing version) and a newly proposed method. The new method involves using special specimens that allow T-type rosettes to be bonded to determine Poisson’s ratio, whose value of 0.14 was thus determined. SEM images of the failure surfaces were presented and interpreted. A finite element analysis (FEA) of the specimens tested in compression is also presented. The first analyzed case considers the homogeneous and orthotropic composite, loaded with a uniformly distributed force. The normal stress in the central section of the specimen, determined with FEA, has an error of 6.52% compared to that determined experimentally. Additionally, the strain in the center of the strain gauge, determined with FEA, has an error of 4.76% compared to the measured one. In the second case studied with FEA, the sample is loaded with a quasi-concentrated force, which can move in the direction of the symmetry axes of the cross-section, to study the effect of the eccentricity of the compression force on the state of stress. It was shown that the eccentricity of the force has a great influence: the stress distribution in the section of the specimen becomes strongly non-uniform. For a force eccentricity of 0.4 mm in the direction of the OX axis, the minimum stress decreases by 53.7%, and the maximum stress increases by 55.4%. In order to analyze the influence of some manufacturing defects, two other cases were analyzed by FEA, in which it was assumed that the thicknesses of the outer resin layers were modified, making them asymmetrical. For this final FEA, the specimen was considered to be composed of laminates. These results demonstrate the special attention that must be paid to the centric application of force in compression testing.

Characterization of Stages of CO2-Enhanced Oil Recovery Process in Low-Permeability Oil Reservoirs Based on Core Flooding Experiments

Understanding the CO2 displacement mechanism in ultra-low-permeability reservoirs is essential for improving oil recovery. In this research, a series of displacement experiments were conducted on sandstone core samples from the Chang 6 reservoir in the Huaziping area using a multifunctional core displacement apparatus and Nuclear Magnetic Resonance (NMR) technology. The experiments were designed under conditions of constant pressure, variable pressure, and constant effective confining stress to simulate various reservoir scenarios. The results indicated that the distribution characteristics of the pore structure in the rock samples significantly influenced the CO2 displacement efficiency. Specifically, under identical conditions, rock cores with a higher macropore ratio exhibited a significantly enhanced recovery rate, reaching 68.21%, which represents a maximum increase of 31.97% compared to cores with a lower macropore ratio. Though fractures can facilitate CO2 flowing through pores, the confining pressure applied during displacement caused a partial closure of fractures, resulting in reduced rock permeability. Based on the oil-to-gas ratio and oil recovery in the outlet section of the fractured rock samples, the CO2 displacement process exhibited five stages of no gas, a small amount of gas, gas breakthrough, large gas channeling, and gas fluctuation. Although the displacement stage of different cores varies, the breakthrough stage consistently occurs within the range of 2 PV. These insights not only enhance our understanding of CO2 displacement mechanisms in low-permeability reservoirs but also provide actionable data to inform the development of more effective CO2-EOR strategies, significantly impacting industrial practices.

Allelopathic interactions of Carthamus oxyacantha, Macrophomina phaseolina and maize: Implications for the use of Carthamus oxyacantha as a natural disease management strategy in maize.

Fungicides are used to control phytopathogens but all these fungicides have deleterious effects. Allelopathic interactions can be harnessed as a natural way to control the pathogens but there are no reports that show the allelopathic interactions of donor plant, recipient crop, as well as the target plant pathogen and the material used for inoculum production. So, in the present study, the suitability of Carthamus oxyacantha M. Bieb. was assessed against Macrophomina phaseolina, the cause of charcoal rot in maize. Among the various treatments in pot experiment, a negative control, 3 concentrations of inoculum (1.2×105, 2.4×105, and 3.6×105 colony forming units (CFU) mL-1, 3 concentrations (0.5, 1.0, and 1.5% w/w) of C. oxyacantha along with an autoclaved M. phaseolina (Mp) and C. oxyacantha alone were included to investigate their allelopathic effects on maize, not investigated earlier. Maximum suppression of the disease was observed by 1.5% (w/w) concentration of C. oxyacantha. Soil amendment with C. oxyacantha significantly suppressed the disease incidence (DI) and disease severity index (DSI) in charcoal rot of maize up to 40 and 55%, respectively over the strongest level of inoculum (Mp3). C. oxyacantha not only reduced area under disease incidence progress curve (AUDIPC) and area under disease severity progress curve (AUDSPC), but also improved the morphological, biochemical and physiological parameters of maize. The maximum increase of 48, 65, and 75% in values of shoot length (SL), shoot dry mass (SDM), and root dry mass (RDM), respectively was observed by application of the highest concentration of C. oxyacantha in the treatment Mp1+Co3, over infested control (Mp1). Photosynthetic pigments, such as chlorophyll a, chlorophyll b and carotenoids were increased to 58, 64, and 46%, respectively over Mp1, by the application of C. oxyacantha. Carbon assimilation rate (A), stomatal conductance (gs), rate of transpiration (E), and internal carbon dioxide concentration (Ci) were significantly increased to 58, 48, 48, and 20%, respectively over infested control (Mp3), by application of C. oxyacantha concentration 1.5 (w/w). Moreover, defense enzymes like superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities were boosted up to 27, 28, and 28% over Mp3, respectively. Positive allelopathy of C. oxyacantha towards maize and negative allelopathy towards M. phaseolina makes C. oxyacantha a suitable candidate for charcoal rot disease control in maize.

Experimental Study on the Influence of Sidewall Excavation Width and Rock Wall Slope on the Stability of the Surrounding Rock in Hanging Tunnels

Hanging tunnels are a unique type of highway constructed on hard cliffs and towering mountains, renowned for their steep and distinctive characteristics. Compared to traditional full tunnels or open excavations, hanging tunnels offer significant advantages in terms of cost and construction time. However, the engineering design and construction cases of such tunnels are rarely reported, and concerns about construction safety and surrounding rock stability have become focal points. Taking the Shibanhe hanging tunnel as a case study, this paper focuses on the stability of the surrounding rock during the excavation of limestone hanging tunnels using physical analog model (PAM) experiments and numerical calculation. Firstly, based on the similarity principle and orthogonal experiments, river sand, bentonite, gypsum and P.O42.5 ordinary Portland cement were selected as the raw materials to configure similar materials from limestone. Secondly, according to the characteristics of hanging tunnels, geological models were designed, and excavation experiments with three different sidewall excavation widths and rock wall slopes were carried out. The effects of these variables on the stress and displacement behavior of the surrounding rock were analyzed, and the laws of their influence on the stability of the surrounding rock were explored. Finally, numerical simulations were employed to simulate the tunnel excavation, and the results of the numerical simulations and PAM experiments were compared and analyzed to verify the reliability of the PAM experiment. The results showed that the vertical stress on the rock pillars was significantly affected by the sidewall excavation widths, with a maximum increase rate of 53.8%. The displacement of the sidewall opening top was greatly influenced by the sidewall excavation widths, while the displacement of the sidewalls was more influenced by the rock wall slope. The experimental results of the PAM are consistent with the displacement and stress trends observed in the numerical simulation results, verifying their reliability. These findings can provide valuable guidance and reference for the design and construction of hanging tunnels.

Determination of rational parameters of chemical transesterification technology of sunflower oil

The object of the study is the process of chemical transesterification of sunflower oil. Liquid vegetable oils are an important component in the products of chemical, cosmetic, paint, food and other industries. Among other oils, sunflower oil is of exceptional industrial importance. Chemical transesterification technology is used to obtain oils, fats and their mixtures with specified properties required for various industries. An important task is to develop rational conditions for the oil transesterification process using a highly efficient and safe catalyst. The process of chemical transesterification of refined deodorized frozen sunflower oil according to DSTU 4492 (CAS Number 8001-21-6) using potassium glyceroxide was studied. The original oil has the following parameters: peroxide value 0.2 ½ O mmol/kg, acid value 0.1 mg KOH/g, moisture mass fraction 0.03 %, crystallization temperature –18.38 °С. The effect of transesterification parameters on the oil crystallization temperature was examined. The catalyst concentration in all experiments was 0.45 % by weight of the oil. The oil crystallization temperature was determined by differential scanning calorimetry. Rational parameters of oil transesterification were defined: temperature 110 °C, duration 1.5 hours. Under these conditions, there is a maximum increase in the oil crystallization temperature (up to –4.1 °С). The effectiveness of the rational oil transesterification parameters was confirmed by changes in the triglyceride composition by chromatography analysis. The obtained rational conditions for the chemical transesterification of sunflower oil in the presence of the potassium glyceroxide catalyst can also be used in the processes of oil transesterification with other raw materials using this catalyst.

Dosimetric Evaluation of Beam-specific PTV and Worst-case Optimization Methods for Liver Proton Therapy.

In spot-scanning proton therapy, intra-fractional anatomical changes by organ movement can lead to deterioration in dose distribution due to beam range variation. To explore a more robust treatment planning method, this study evaluated the dosimetric characteristics and robustness of two proton therapy planning methods for liver cancer. Two- or three-field treatment plans were created for 11 patients with hepatocellular carcinoma or metastatic liver cancer using a single-field uniform dose (SFUD) technique. The plans were optimized using either beam-specific planning target volume (BSPTV) or worst-case optimization (WCO). The target coverage for the gross tumor volume (GTV), planning target volume (PTV), and organs at risk (OAR) parameters related to toxicity were calculated from the perturbed dose distributions, considering setup and range uncertainties. Statistical analyses of the BSPTV and WCO plans were performed using the Wilcoxon signed-rank sum test (p<0.05). The calculation times for a single optimization process were also recorded and compared. The robustness of the WCO plans in the worst-case scenario was significantly higher than that of the BSPTV plan in terms of GTV target coverage, prevention of maximum dose increase to the gastrointestinal tract, and the dose received by normal liver regions. However, there were no significant differences in PTV, and the calculation time required to create the WCO plan was considerably longer. In SFUD proton therapy for liver cancer, the WCO plans required a longer optimization time but exhibited superior robustness in GTV coverage and sparing of OARs.

Preparation and Mechanical Properties Analysis of Rare Earth Filling Ethylene‐Allene Monomer Rubber Composite

AbstractEthylene propylene diene monomer (EPDM) rubber is used in critical sectors such as national defense, military, and aerospace. However, it has performance limitations under high temperatures, affecting its dynamic mechanical properties, creep, and stress relaxation. To overcome these limitations, rare earth cerium oxide (CeO2) was incorporated as a filler into EPDM in this study, which enhances its properties and makes it suitable for the demanding applications. It could be seen that the CeO2‐enriched EPDM has significantly improved mechanical characteristics at elevated temperatures. The Young's modulus of CeO2‐enriched EPDM increased by about 100 %, while the energy storage modulus reaches a maximum increase of around 140 % at 165 °C. The addition of CeO2 improves its damping properties, provides better creep and stress relaxation resistance, and results in greater residual strain recovery. At room temperature, the impact on the stress relaxation rate at 50 % strain is minimal for the material EPDM, and it is almost negligible for the material EPDM/CeO2.These findings demonstrate that CeO2‐enriched EPDM has enhanced performance under high‐temperature conditions. Under elevated temperature conditions, EPDM enriched with CeO2 exhibits enhanced mechanical properties, superior creep resistance, and stable stress relaxation behavior, rendering it more adept at withstanding the rigorous conditions encountered in aerospace applications.

Silver Nanoparticles (AgNPs) Act as Nanoelicitors in Melissa officinalis to Enhance the Production of Some Important Phenolic Compounds and Essential Oils

ABSTRACTNanoparticles (NPs) are well‐known biostimulants in plant biotechnology, utilised to enhance the physical properties of plants and exhibit positive effects on them. The important key role is the most suitable type, effective dose and size of NP to be used in plant tissue culture systems. In this study, various concentrations of silver nanoparticles (AgNPs; 0, 25, 50, 75 and 100 μg L−1) were tested as elicitors in callus culture with the aim of enhancing secondary metabolite production in lemon balm (Melissa officinalis L.). According to the results obtained, callus formation rates have shown an increase in all applications compared to the control group. The highest callus formation, weight and diameter were observed in 50 μg L−1 application. In this application, the callus structure was compact and its colour was green. However, the aromatic compounds, neral and geranial increased significantly in 25 μg L−1 application. The maximum increase in phenolic compounds such as caffeic acid, chlorogenic acid, proto‐catechic acid, hesperidin and p‐coumaric acid was observed in the 75 μg L−1 AgNP and the highest increase in rosmarinic acid compound was determined in the 50 μg L−1 application. The study found that AgNP applications are an effective method for increasing the production of secondary metabolites in medicinal and aromatic plants, such as lemon balm, in vitro.

Fluctuation of Bone Marrow Lesions and Inflammatory MRI Markers over 2 Years and Concurrent Associations with Quantitative Cartilage Loss.

To assess whether change of semiquantitatively magnetic resonance imaging (MRI)-defined bone marrow lesions (BMLs) and inflammatory markers is associated with change in quantitatively-assessed cartilage loss in the femorotibial joint (FTJ) in knees with radiographic osteoarthritis (OA) over 24 months. Participants were included from the IMI-APPROACH and the Osteoarthritis Initiative FNIH studies. Semiquantitative MRI assessment was performed for BMLs, Hoffa- and effusion-synovitis. Quantitative cartilage thickness measurements were performed manually. Definitions of change included number of subregions with BMLs, change in sum and change in maximum increase in size. Change in Hoffa-synovitis and effusion-synovitis was categorized in addition. Between-group comparisons regarding cartilage loss in the FTJ, medial and lateral compartments were performed using analysis of variance (ANOVA). A total of 629 participants were included. Knees without any BMLs at baseline (BL) and follow-up (FU) had significantly less cartilage loss compared to the other subgroups. Change in both directions in the sum score of BMLs was associated with increased rates of cartilage loss. Maximum increase in size of BMLs was associated with increased rates of cartilage loss (FTJ increase by 2 grades -0.183 mm, 95% CI [-0.335, -0.031], by 3 grades -0.306 mm, [-0.511, -0.101]). Worsening of Hoffa-synovitis was associated with increased rates of cartilage loss. Knees without BMLs at BL and FU showed lowest rates of cartilage loss. Knees with an increase in BML size showed increased rates of concurrent cartilage loss. Approaches with the aim to inhibit BML development, avoidance of increase in size and avoidance of Hoffa-synovitis worsening may have beneficial effects on cartilage loss.

Comprehensive Statistical Analysis of ISSN Records

The history of the origin and transformation of the ISSN Register is considered, and all publications available through Google Scholar and Semantic Scholar on the number of ISSN records and their dynamics are collected together. Data on the number of entries in the ISSN Register by country for 2014 and 2021 is presented, along with the seven-year increase in these entries in comparison with similar data for 1991 through 1998. From these data, the top ten countries were analyzed based on the maximum increase in records over these two seven-year periods. It is shown that the first list of countries with the maximum increase in the number of ISSN records for 2014 through 2021 included exclusively developing countries, and the second list (1991–1998) included mainly developed countries. Similar increases in the number of ISSN records were analyzed for the languages of serial publications and it was shown that in both language lists there was only the Turkish language and the leading European languages were absent. It is shown that the total contributions of ISSN records of leading countries and languages to the total number of ISSN records satisfy the Pareto principle for all years studied. The calculations were made on the indices of linguistic liberalization of the information space of states and information and linguistic influence (or language expansion) according to ISSN indicators. It is shown that aggregating countries by language has made it possible to significantly reduce the discrepancy between the total ISSN records for countries in which a particular language predominates and the ISSN records for a given language. These differences for calculations for 2014 and 2021 levels did not exceed 9% for English, Spanish and Portuguese, and 14% for French, which corresponds to the languages of former colonial empires. In conclusion, a linear regression relationship between ISSN/10 thousand people and GDP per capita with moderate values of the correlation coefficient was obtained in two versions, which indirectly confirms the Constancy Hypothesis.

Size effect modellings of axial compressive failure of RC columns at low temperatures

This paper applied a thermal-mechanical sequential coupled mesoscopic simulation method to explore the axial compression performance and the corresponding size effect of Reinforced Concrete Columns confined by Stirrups (i.e., RCCS) at low temperatures, with considering the interaction between concrete meso-components and steel bars as well as the low-temperature effect of mechanical parameters. Based on the heat conduction analysis, the axial compression mechanical failure behavior of RCCS with four structural sizes (i.e., 267 × 267 × 801, 400 × 400 × 1200, 600 × 600 × 1800 and 800 × 800 × 2400 mm) and two stirrup ratios (i.e., 1.26% and 2.89%) at different temperatures (i.e., T = 20, −30, −60 and −90°C) was subsequently simulated. The effects of temperature, structural size and volume stirrup ratio on axial compression properties were quantitatively discussed. The results showed that the peak strength of RCCS increased with the decreasing temperature, and the smaller-sized RCCS showed a stronger effect of low-temperature enhancement. Both the residual strength and displacement ductility coefficient decreased with the decreasing temperature. The peak strength, residual strength and displacement ductility coefficient of RCCS decreased with the increasing structural size, showing obvious size effects. The size effect on peak strength increased with the decreasing temperature, (the maximum increase was nearly 140%), but the size effect on displacement ductility coefficient decreased (the maximum decrease was nearly 70%). The peak strength, residual strength and ductility were enhanced with the increasing volume stirrup ratio, which was helpful to reduce the influence of size effect. Finally, an improved size effect theoretical model was proposed, which can effectively predict the axial compressive strength of RCCS with different structural sizes and stirrup ratios at room and low temperatures. The present research results can provide reference for the large-scale engineering application of RCCS in low-temperature environments.

The analysis of Gurney flap applications for autonomous underwater gliders

ABSTRACT In this paper, the Gurney flap structure (GF) from aeronautical research was applied to underwater gliders for improving the lift-to-drag ratio. Firstly, the numerical simulation method was used to verify the lift enhancement principle of the GF structure and the feasibility of its application to autonomous underwater gliders (AUG). Secondly, the performance of different GF was simulated and analysed, and a variable GF structure was proposed with the requirements of the operating modes. The GF parameters were optimised by a genetic algorithm. The results show that the performance of GF in water is similar to that in air, so it is feasible to apply GF to AUG. When the height of GF is close to the turbulent boundary layer of the trailing edge of the wing, the lift-to-drag ratio is significantly improved, especially in the range of small angle of attack and the maximum increase is up to 30%.