Effect Size Research Articles

Size Effect on Shear Behaviors of 3D-Printed Soft Rock-like Materials Under Different Shear Velocities

The shear failure of rock masses is one of the primary causes of underground engineering instability. The shear mechanical behavior of rocks at different sizes is of great significance for studying the shear failure pattern of engineering rock masses. However, due to the presence of various joints and defects in natural rocks, the obtained rock specimens exhibit significant discreteness, making it difficult to customize specimen sizes for size effect studies. In recent years, 3D printing (3DP) technology has gained widespread application in rock mechanics tests due to its high printing precision and ability to form specimens in a single step with minimal discreteness. Among these, specimens prepared using sand-powder 3DP exhibit elastoplastic mechanical characteristics similar to those of natural rocks. Therefore, this study utilized sand-powder 3DP to prepare rock-like specimens of four different sizes and conducted compression shear tests under three different shear velocities. The shear strength, shear strain, and wear of the shear surfaces were analyzed as functions of specimen size and shear velocities. The results indicate that under the same shear velocity, the shear strength of the specimens is negatively correlated with specimen size. The peak shear strain is generally unaffected by shear velocities, but it increases initially and then decreases with increasing specimen size. As specimen size increases, the degree of specimen damage intensifies, and larger specimens are more prone to developing derived fractures. This study broadens the application of sand-powder 3DP technology in investigating the shear mechanical properties of soft rocks, offering novel insights into the study of size effects in rock mechanics. However, the current research does not encompass tests on 3D-printed rock specimens with varying printing directions, nor does it delve into the role of fractures in size effect analyses. Future investigations will aim to address these limitations, thereby advancing the applicability of 3D printing technology in rock mechanics research and enhancing its contributions to the field.

Effect of Firm Size, Profitability and Leverage on Voluntary Disclosure of Insurance Companies in Nigeria

The level at which listed firms in Nigeria disclose voluntary information is at an increasing rate yearly. This therefore, led to this research as to what factors influence this voluntary disclosure by insurance companies. This study primarily tries to determine the effects of firm size, profitability, and leverage on the content and degree of voluntary disclosure by insurance companies in Nigeria. All 15 insurance companies listed on the Nigerian Stock Exchange were used as the study's population, and a census sampling technique was applied to arrive at a sample size of ten (10) insurance companies. Data were collected from the insurance companies’ annual reports and accounts. Multiple regression analysis was used to investigate the effects of firm size, leverage, and profitability on voluntary disclosure. The results indicated that leverage and company size have a positive but insignificant effect on voluntary disclosure. Indeed, profitability has a negative but significant effect on voluntary disclosure. It is, therefore, recommended that insurance companies should embark on good corporate governance practices such as the voluntary disclosure of information in order to attract investors and improve their performance.

Hybrid Nanofluids in Solar Thermal Collectors: Size and Cost Reduction Opportunities

Solar thermal collector, an alternative way to harvest renewable solar energy, requires high heat transfer area. Hybrid nanofluid has potential to reduce the size of the collector due to its high thermal conductivity and low specific heat capacity. This study investigates the effects of Multi-Walled Carbon Nanotubes (MWCNT) combine with metal oxides, including Al2O3, CeO2, TiO2, ZnO at the volume ratio of 1:4 between MWCNT and metal oxides with a total of 1 vol.% in water. The investigation focuses on assessing this nanofluids with 1 kg/min mass flow rate for its effect in size and cost reduction. Following the validation of nanofluids properties predictor and the numerical model of flat plate solar collector with experimental data, the effects in terms of size and cost reduction is evaluated. In best case scenario, the use of MWCNT-TiO2 can reduce the size of flat plate solar thermal collector by up to 8.54% and cost by 5.15% compared to using water as the heat transfer fluid.

Kinetic research and optimized particle size for high-performance of CdS NP photocatalyst.

Metal semiconductors are important materials for photocatalytic technology, and their morphology and size have the great influence on photocatalytic performance. Therefore, the detailed exploration of the size effect is significant for the photocatalytic reaction. Herein, CdS nanoparticles (NPs) with different particle sizes were prepared for photodegradation of methylene blue, and the effects of particle size on photodegradation were studied using CdS NPs as a catalyst. The rate-determining step of photodegradation is determined theoretically by deriving the kinetic order of the photodegradation reaction, and the relationships of size and performance are explored. The results show that the particle size of the CdS NP catalyst has an obvious influence on the photodegradation rate and the rate constant, and the size effects show a "volcano" trend, implying that the catalyst activity is best when the particle size of the catalyst is moderate. The size influences on the adsorption/desorption, light utilization, and carrier efficiency of the catalyst originate from the influence of size on the surface properties and energy band. This study provides a new understanding on the effect of catalyst size on its properties, and this finding of optimum sizes of catalyst possessing better activity is valuable, which has a significant guidance for developing high-performance catalytic materials.

Aerodynamic Drag Coefficient Analysis of Heavy-Duty Vehicle Platoons: A Hybrid Approach Integrating Wind Tunnel Experiments and CFD Simulations

Heavy-duty vehicle (HDV) platooning, facilitated by vehicle-to-vehicle communication, plays a crucial role in transforming logistics and transportation. It reduces fuel consumption and emissions while enhancing road safety, supporting sustainable freight strategies and the integration of autonomous vehicles. This study employs a hybrid approach combining wind tunnel experiments and Computational Fluid Dynamics (CFD) simulations to analyze HDV platoon aerodynamics. The approach has two sequential phases: single-HDV simulation validation and multi-HDV platooning simulation. In the first phase, a single HDV CFD simulation is validated against NASA’s benchmarks, with optimized mesh generation, proper models, and conditions, and errors minimized below 1%. In the second phase, the validated model is used for multi-HDV platooning simulations, maintaining consistent mesh structures, physical models, and boundary conditions. Various platoon configurations are explored to assess the effects of speed, inter-vehicle spacing, and platoon size and position on aerodynamic drag, with virtual wind tunnel simulations evaluating drag coefficients. Our findings reveal that inter-vehicle spacing critically influences drag. An optimal range of 0.25 to 0.5-times the HDV length is identified to achieve an effective balance between safety and fuel efficiency, reducing platoon aerodynamic drag by 13–44% compared to single HDVs. While platoon speed is generally limited to impacting drag, it becomes more pronounced when an HDV platoon has very small inter-vehicle spacings, or in platoons exceeding five HDVs. Moreover, as the platoon size increases, the overall aerodynamic drag coefficient diminishes, particularly benefiting the rear HDV in larger platoons with smaller inter-vehicle spacing. These insights offer a comprehensive understanding of HDV platoon aerodynamics, enabling logistics enterprises to optimize platoon configurations for fuel savings, improved traffic flow, larger platoon formation, and enhanced transportation safety.

Ratio Analyses Estimating Financial Risk: Econometric Study Retail Companies the Indonesia Stock Exchange 2020-2023

Aims: This study analyses the effect of activity ratios, sales growth, profitability, and company size on the financial distress of retail companies on the Indonesia Stock Exchange from 2020 to 2023. Study Design: The study uses data on activity ratios, sales growth, profitability, and company size as independent variables and financial distress as the dependent variable. Place and Duration of Study: The research was conducted in retail companies listed on the Indonesia Stock Exchange with a population of retail company subsectors and using purposive sampling criteria. The research data used financial reports published in 2020-2023. Methodology: This type of research is quantitative. The research was tested with SPSS 25 using logistic regression. The total population in the study was 32 types of companies in the retail subsector with several types of companies such as drug retail & distributors, food retail & distributors, supermarkets & convenience stores (minimarkets), department stores, apparel & textile, automotive retail, and electronic retail. Purposive sampling obtained 108 unbalance data for 4 years of observation listed on the Indonesia Stock Exchange in 2020-2023 financial distress was tested with the Altman Z-Score method through logistic regression test. Result: Utilizing logistic regression and the Altman Z-Score, the study reveals that activity ratios and profitability significantly negatively affect financial distress, while sales growth and company size do not have a significant impact. Conclusion: These findings provide valuable insights for stakeholders, emphasizing the importance of optimizing asset efficiency and profitability to mitigate financial distress.

Environmental drivers of seed persistence and seedling trait variation in two Neltuma species (Fabaceae)

Abstract The endemic tree Neltuma caldenia Burk. and the shrub Neltuma flexuosa var depressa F.A. Roig (Fabaceae; subfam: Mimosoideae) are two promising species from the central region of Argentina, with high potential for use in the restoration of disturbed environments, for extensive livestock grazing and apiculture. Both species have seeds with physical dormancy. Ecological study of native species is important from the point of view of rehabilitation of degraded areas by natural regeneration or via seed-based programmes. The objective of this study was to evaluate soil seed bank persistence and seedling traits to understand variation among different populations of each of the study species growing along an ecological gradient and to identify potential components driving this variation. Home environments influenced seed bank persistence, which was higher in populations originating from more arid and unpredictable environments where it could act as a bet-hedging strategy between years and seasons. We also observed differences associated with seedling growth traits between the species and populations. Populations with higher seed persistence were associated with greater seedling growth in N. caldenia. The rapid elongation rate of N. caldenia seedlings growing in large populations and unstable environments could help their ability to escape drought by accessing deeper soil moisture and would confer a high relative competitive ability. In contrast, N. f. var depressa displayed higher seed persistence, which was associated with more arid and unstable conditions and correlated with lower seedling growth, possibly due to an inbreeding depression effect, resulting from the presence of mother plants in low-densities or being isolated from other individuals. There was no effect of population size on seed persistence. To better understand seed persistence and associated seedling trait variation, future studies need to consider the genotype, environment and landscape conditions.

The risk status, signatures of adaptation, and environmental suitability of village-based indigenous chickens from certain regions of Limpopo and KwaZulu-Natal provinces of South Africa

Indigenous chickens are an important Farm Animal Genetic Resource (FAnGR) in South Africa as they alleviate poverty and are a source of protein. Climate change and market demand for high-performing exotic breeds threaten and undermine locally adapted village chickens. The current study explored the risk status and signatures of adaptation of village-based indigenous chickens from two provinces and mapped their environmental suitability across the country. A total of 244 village chickens from rural areas of the Capricorn (n = 85) and Sekhukhune (n = 113) districts of Limpopo province; the Harry Gwala (n = 21) and uMzinyathi (n = 25) districts of KwaZulu-Natal province were genotyped using the Illumina 60K BeadChip. The conservation flock comprised Ovambo (OV; n = 10), Potchefstroom KoeKoek (PK; n = 20), and Venda (VD; n = 20). Naked Neck (NN; n = 20), New Hampshire (NH; n = 10), White Leghorn (WL; n = 10), and White Plymouth Rock (WR; n = 10) from the Agricultural Research Council Poultry Breeding Unit were used as reference populations and representative of flocks under conservation. The effective population size (Ne) in village chickens and conserved flocks ranged from 18 to 53 and 26 to 38 at 12 generations ago, respectively. PC1 and PC2 explained 5.64% of the total variation, which resulted in five clusters with the Venda, Naked Neck, and White Leghorn being separated from village chickens. The first three redundancy analysis (RDA) axes capture 46.8% of the total genetic variation used to detect significant outlier SNPs. A total of 386 outlier SNPs associated with all 10 environmental variables were detected. Using ecological niche modeling, chickens from Dipakakeng, Mgababa, and Podu villages, Limpopo, had a localized predicted suitability probability, while chickens originating from Nhlonga village, KwaZulu-Natal, had a broader distribution of predicted suitability habitats with elevation and BIO6 being important variables. The results of this study provide insight into the risk status, geographic suitability, and contributing environmental factors of indigenous chickens that can be used to influence conservation and improvement decisions.

The Impact of Dexamphetamine Treatment for Obesity on Executive Function: A Double-Blind Randomised Controlled Pilot Study

Background: Amphetamines increase dopamine levels in mid-brain regions which, in turn, impact top-down executive function. Repeated exposure is linked to substance use disorders. Nonetheless, amphetamines are used to manage attention-deficit/hyperactivity disorder (ADHD) and eating-related disorders. In ADHD, amphetamines upregulate a system characterised by low dopaminergic tone, assisting to improve executive function. A similar process might be at play with eating disorders; however, the effect of amphetamine treatment on executive function in this case has not been thoroughly considered. Methods: Participants (N = 52, Mage = 47.06, SD = 12.29) with a body mass index of 25–60 were randomised to treatment (6-week dexamphetamine titration) or control (placebo) groups. They completed an executive function measure—Barkley Deficits in Executive Functioning Scale (BDEFS-SF)—and response inhibition task—Stop-Signal Task (SST)—at Baseline, throughout titration, at Maintenance, and at Follow-up. Mixed effects models examined whether BDEFS-SF score or the SST variable, stop-signal reaction time (SSRT), changed across sessions as a function of treatment. Results: There was no effect of group (p = 0.440), but an effect of session (p = 0.024) on BDEFS-SF, with scores at Time 2 (p = 0.011, 95% CI [0.47, 3.49]) and Maintenance (p = 0.022, 95% CI [−4.89, −0.39]), respectively, higher and lower than other timepoints. There was no group by session interaction (p = 0.659). R2 (conditional) = 0.74; ICC = 0.73. There was an effect of group (p = 0.039) and session (p < 0.001) on SSRT, but no interaction (p = 0.707). Baseline SSRT was significantly longer than the mean of all subsequent timepoints (p < 0.001, 95% CI [16.29, 33.84]). R2 (conditional) = 0.47; ICC = 0.39. Conclusions: There was no discernible impact of amphetamine treatment for obesity on executive function. Our results suggest some variation related to sample size and/or practice effects. Thus, while treatment appears unlikely to render individuals susceptible to substance use disorders, parallels with ADHD might be overstated.

Numerical Study on Fire Suppression by Water Mist in Aircraft Cargo Compartments: Effects of Spray Pattern, Droplet Size, and Nozzle Layout

Aircraft cargo compartment fires are one of the main threats to the safety of civil aircraft. In this study, a series of numerical simulations on the fire suppression performance of water mist in cargo compartments was carried out to examine the effects of the spray pattern, droplet size, and nozzle layout. The fire dynamics simulator (FDS) code was used to construct a fire suppression scenario in a full-scale aircraft cargo compartment. The results show that the extinguishment time of a corner fire was longer compared with center and sidewall fires due to the relatively larger distance from the nozzle and, therefore, a lower effective number of droplets reaching the flame area. Solid and hollow spray patterns showed significant differences in the spray coverage area. For a fixed flow rate, the hollow spray showed better fire suppression performance than solid spray. When the droplet size varied from 50 to 400 µm, the fire extinguishment time first increased and then decreased, corresponding to the dominant mechanism of the smothering effect of small droplets and the cooling effect of large droplets. In addition, the nozzle layout affected the water coverage on the ground of the cargo compartment. With an increase in nozzle number, the water mist flux was more evenly distributed and the fire extinguishment effect also increased.

Effect of Indenter Load on Vickers Microhardness and Indentation Depth of One Resin Composite

The load and size of the indentation may affect the hardness value. This study investigated the effect of the indentation size on the microhardness of one resin-based composite (RBC). Metal molds 4 mm deep and 12 mm in diameter were filled with Tetric EvoCeram Bulk Fill (Ivoclar) and light-cured for 10 s using a broad-spectrum LED curing light. The Vickers microhardness and the degree of conversion (DC) at the top and bottom surfaces were measured 24 h later before and after polishing the RBC. The microhardness measurements were made using 50, 100, 300 and 1000-gf loads with the same 8 s dwell time. The DC was measured in the same region using mid FT-IR spectroscopy. Repeated measures analysis of variance tests were used to determine if the surface (top vs. bottom) or the indenter loads had a significant effect on the VH, or if polishing affected the VH and the DC (alpha = 0.05). It was found that the indenter load did not affect the Vickers hardness of the unpolished top surface (p = 0.759), the polished top surface (p = 0.374), or the polished bottom surface (p = 0.083) of the Tetric EvoCeram Bulk Fill. Increasing the indenter load did increase the VH of the unpolished surface at the bottom (p < 0.0001). Polishing increased the DC by 13.5% at the top and by 46.7% at the bottom surface.

Fast Design Space Exploration for Always-On Neural Networks

An analytical model can quickly predict performance and energy efficiency based on information about the neural network model and neural accelerator architecture, making it ideal for rapid pre-synthesis design space exploration. This paper proposes a new analytical model specifically targeted for convolutional neural networks used in always-on applications. To validate the proposed model, the performance and energy efficiency estimated by the model were compared with actual hardware and post-synthesis gate-level simulations of hardware synthesized with a state-of-the-art electronic design automation (EDA) synthesis tool. Comparisons with hardware created for the Eyeriss neural accelerator showed average execution time and energy consumption error rates of 3.33% and 13.54%, respectively. Comparisons with hardware synthesis results showed an error of 3.18% to 9.44% for two example neural accelerator configurations used to execute MobileNet, EfficientNet, and DarkNet neural network models. Finally, the utility of the proposed model was demonstrated by using it to evaluate the effects of different channel sizes, pruning rates, and batch sizes in several neural network designs for always-on vision, text, and audio processing.

Genetic Structural Changes While Maintaining Effective Population Size of Bighead Catfish in Nong Han Lake: Implications of Metapopulation Dynamics or Release Activities

ABSTRACTThe Bighead Catfish (Clarias macrocephalus) plays crucial roles in the ecosystem and as a protein source for humans in Nong Han Lake, Thailand, but their ecological and population dynamics, along with their genetic diversity and structure, are poorly understood. Therefore, the dynamics of genetic diversity and differentiation of bighead catfish populations in Nong Han Lake were investigated during 2018–2023 to provide essential insights into preserving biodiversity and maintaining ecological balance. Microsatellite genotyping was used to assess the genetic diversity of one bighead catfish population in 2018, two populations in 2023, and one hatchery population. Potentially stable, effective population sizes and distinct genetic clusters of these populations were identified, which represented the resilience of populations and the complexity of their genetic dynamics. Genetic differentiation between sample dates and among populations suggested that limited recent and historical genetic exchanges could potentially influence genetic structure. The impact of ecological factors, including flooding, metapopulation dynamics, and human interventions, was indicated by unique and shared gene pools among populations and subpopulations in different years. Ongoing assessment of genetic diversity and structure of bighead populations is essential for developing conservation strategies and ensuring sustainable management.

THE IMPACT OF CAPITAL STRUCTURE ON BANK PERFORMANCE IN TURKIYE

The aim of this study is to examine the impact of capital structure on Turkish banking performance by using panel regression model for the period between 2012 and 2023. The ratio of return on assets (ROA) and return on equity (ROE) are used as a dependent variable which are one of the important indicators of the banking performance. There are 9 bank-spesific and 2 macroeconomic (inflation and economic growth) independent variables in the analysis. Panel data analysis results reveal that the capital structure [Debt ratio (DTA) and Debt to equity ratio (DTE)] negatively impacts business performance (ROA) of Turkish private deposit banks. The financial performance, which is measured by ROA, is significantly and negatively associated with variables such as Non-Performing loan ratio (NPL), credit risk (CIR) and cost management (OA), whereas effect of bank size (BS), economic growt (GDP) and inflation (INF) have positive impact. On the other hand, the effects of DTA, DTE, BS, NPL, CIR, OA and GDP on ROE are significant. Besides, the effects of DTA, BS and GDP are positive, whereas the effect of DTE, NPL, CIR and OA are negative. The study concludes that the capital structure proxies have impact on financial performance of Turkish private deposit banks measured both by return on assets and return on equity.

Effect of DNA target size on the efficiency of chimerism measurement in circulating free plasma DNA

Introduction. The analysis of free circulating DNA (cfDNA) holds promise for molecular diagnostics, but its fragmentation and low concentration can complicate PCR analysis.Objective. To investigate the effect of target length on the amplification efficiency of Y-chromosome markers from cfDNA.Material and methods. Fifty cfDNA samples were obtained from 39 patients: patients after liver transplantation (n=19), patients with acute leukemia after allogeneic hematopoietic stem cell transplantation (n=10), and pregnant women (n=10). In addition, we prepared 16 chimeric samples by sequential dilution of male cfDNA into female cfDNA from healthy donors. We determined the proportion of male cfDNA using the Y-chromosome marker S02, which is 211 bp in length as suggested by M. Alizadeh et al. We also modified Alizadeh's primer design to obtain a DNA target with a length of 138 bp. The proportion of male cfDNA was also determined by fragment analysis using the amelogenin Y marker (84 bp) from the COrDIS Plus kit (Gordiz LLC, Russia).Results. In the three groups of patients, amplification of male cfDNA was more efficient when shorter DNA targets were used (p<0.05). In artificially created ‘chimeras’ with a known ratio of male to female cfDNA, analysis of a marker of 84 bp in length gave values closest to the real ones.Conclusions. In the quantitative models tested so far, shorter PCR targets are preferred for the analysis of cfDNA.

The impact of sidewall copper grain condition on thermo-mechanical behaviors of TSVs during the annealing process

With the drastic reduction of the TSV diameter leading to a critical dimension comparable to the Cu-filled grain size, the grain condition strongly influences the thermo-mechanical behavior of the TSV. In this work, the TSV-Cu cross-section with different grain sizes is characterized by EBSD, confirming that the sidewall grain size (0.638–1.580 μm) is smaller compared to other regions (1.022–2.134 μm). A finite element model (FEM) considering copper grains is constructed by using Voronoi diagrams to investigate the effect of sidewall grain size as well as area on the thermo-mechanical behavior during annealing. The material parameters in the FEM are optimized through nanoindentation inversion and considering the mechanical property anisotropy of copper grains. The yield strength σy and hardening exponent n of TSV-Cu are 74.6 MPa and 0.514. The simulation results indicate that the protrusion of TSV-Cu after annealing tends to increase initially and then decrease with smaller sidewall grain size and area. The maximum increase in protrusion caused by the two variables can reach 6.74% and 14.6%, respectively, relative to the average grain condition. Additionally, the simulation results were validated by quantifying grain boundaries in TSV-Cu samples with varying grain sizes.

Effects of Fine Particle Size on the Characteristics of Coal Bottom Ash as an Environmentally Friendly Material in Concrete Production

In the current era, concern about the responsible disposal of industrial waste and its reuse has increased in all societies from the industry. Therefore, the researchers’ institution is focusing its efforts on developing more environmentally friendly products from recycled waste, particularly in the area of sustainable construction. For instance, one of recycled waste is Coal Bottom Ash (CBA), a by-product of coal combustion that is produced in large quantities from thermal power plants. The aims of this study to investigate the physical, chemical and element characteristics of CBA obtained from thermal power plant in Malaysia. Also, CBA compared with cement characteristics to be used as cement replacement in the concrete mixture. Therefore, numerous tests have been performed to investigate CBA’s physical and chemical characteristics. For physical properties such as specific gravity, particle size analysis, fineness modulus, bulk density and loss on ignition. For chemical properties such as X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) in an effort to obtain sustainable materials from thermal power plant waste. Based on the findings in this study, it can be concluded that CBA can be utilized as cement substitute in the production of concrete mixtures.

Physico-Mechanical Properties of Cellulose Fibers Reinforced Thermoplastic Natural Rubber Composites: Effects of Fiber Size and Fiber Content

Physico-Mechanical Properties of Cellulose Fibers Reinforced Thermoplastic Natural Rubber Composites: Effects of Fiber Size and Fiber Content

The effect of heritage tourism interpretation media type on tourists’ eWOM: the moderating role of travel group size

This study explored the impact of different forms of tourism interpretation (personal vs. nonpersonal) on the electronic word-of-mouth (eWOM) of heritage tourists through the moderating role of travel group size (small vs. large), the mediating role of embodied experience and perceived interpretation quality. A mixed-method approach, including two scenario-based experiments and a heritage tourist attraction-site survey, was applied. The results revealed that there is a significant difference in the impact of personal interpretation and nonpersonal interpretation on tourists’ eWOM, and the mediating effects of embodied experience and perceived interpretation quality and the moderating effect of travel group size were established. For smaller travel groups, personal interpretation had a more significant effect on tourists’ eWOM, perceived interpretation quality, and embodied experience than did nonpersonal interpretation, whereas the opposite was true for larger travel groups. Our findings provide theoretical value and meaningful practical information regarding how to improve tourists’ eWOM and promote the sustainable development of heritage tourism.

Assessment of spray characteristics by studying the effect of nozzle sizes, air-assisted speed and their interaction

Assessment of spray characteristics by studying the effect of nozzle sizes, air-assisted speed and their interaction