Effect Size Research Articles

Mechanical strength analysis of bio composite made by using micro powder made of Prosopis cineraria wood

The Present study examines the mechanical strength of bio-composites fabricated from wood powder of Prosopis cineraria (Khejri) and jute fiber as reinforcement inside an epoxy resin matrix. The mechanical performance of these bio-composites was assessed by altering filler content percentages (0%, 4%, 8%, 12%, 16%, and 20%) and filler particle sizes (250 microns and 500 microns) under standard and carbonate conditions. Tensile strength and impact energy assessments were performed to evaluate the effects of filler content, particle size, and filler type on the mechanical characteristics of the composites. The tensile strength tests reveal that composites with 12% filler and a particle size of 250 microns had the maximum tensile strength, measuring 33.4 MPa under normal settings and 34.8 MPa under carbonate conditions. An increase in filler content over 12% resulted in a reduction in mechanical strength due to filler agglomeration, which decreased stress transfer efficiency. The composites with 250-micron particles consistently demonstrated superior tensile and impact strengths compared to those with 500-micron particles, due to the increased surface area of the smaller particles. Comparative analysis of normal and carbonate conditions demonstrated that carbonate fillers offered superior reinforcement owing to their increased density and enhanced matrix-filler interaction, leading to augmented tensile and impact strength. These findings provide significant insights into the development of bio-composites for structural applications, namely in improving their mechanical strength and durability.

Exploring the Impact of Architectural Variations in ResNet on CIFAR-100 Performance: An Investigation on Fully Connected Layers, Residual Blocks, and Kernel Size

ResNet is one of the leading neutral networks that has been widely applied in image classification. This study built a simple baseline network based on the concept of ResNet and then examines how variations in ResNet’s architecture affect its model performance to provide insights for optimizing network design. Firstly, this study investigates the number of fully connected layers, the results show that by reducing the number of fully connected layers significantly decreases the total number of trainable parameters, which in turn reduces the training time. However, this reduction does not lead to a noticeable improvement in the accuracy after convergence. In addition, increasing the number of fully connected layers not only greatly increases the training time but also leads to overfitting on the CIFAR-100 dataset, slightly reducing the training performance. Secondly, this study also analyzes the influence of reducing number of residual basic block. Analysis suggests that reducing the use of Residual Blocks has significantly negatively impacted both accuracy and training time. This may be because the use of Residual Blocks positively affects the network’s ability to learn features from the CIFAR-100 dataset. Finally, this study explores the effect of bigger kernel size of convolution layer in Residual Basic Block. The outcome demonstrates increasing the kernel size in the Residual Blocks significantly improves both training time and accuracy. Additionally, it was observed that in this variant experiment, a definitive convergence has not yet been clearly established, leaving the possibility that accuracy might continue to improve with more training epochs.

Influence of pH on the synthesis of carbon spheres and the application of carbon sphere-based solid catalysts in esterification

Abstract Size uniformity is a key challenge in the preparation of hydrothermal carbon spheres and a prerequisite for size effect research and many applications of carbon spheres. To solve the scientific problem of low uniformity due to the slow carbonization in traditional preparation of glucose carbon spheres, we propose to add acid/base catalysts to accelerate nucleation, shorten the nucleation time, and improve the size uniformity of carbon spheres. The carbon spheres prepared under base conditions versus acid conditions have higher uniformity and smaller particle size (particle size = 503 nm). This result is due to the faster accumulation of aromatic clusters, shorter nucleation time, and larger number of carbon spheres in alkaline systems. The NaOH-HCSs-based solid acid catalyst as-prepared exhibits excellent catalytic activity, and the esterification rates of levulinic acid and n-butanol maximize to 96.36%.

A meta-analysis of the effects of sacubitril-valsartan on surrogate markers of systemic right ventricular dysfunction in congenital heart disease

Abstract Introduction Dysfunction of systemic right ventricle (sRV) in adult congenital heart disease (ACHD) patients is expectable and often associated with heart failure and other dismal cardiovascular events. Despite limited evidence, several neurohormonal modulators approved for heart failure with reduced ejection fraction (HFrEF) have been used off-label in patients with RV dysfunction1. Sacubitril-valsartan (ARNI) effects on sRV remains poorly studied, with current evidence being limited to small cohorts. Purpose Review and summarize current evidence about the effects of ARNI in ACHD patients with sRV. Methods We performed a systematic review on MEDLINE, EMBASE, COCHRANE, and SCOPUS for articles that included "systemic right ventricle" and "sacubitril valsartan" until January 2024. Two investigators screened the literature and extracted data. Treatment effects were measured by Cohen's d effect-size (EZ) pre and post-ARNI, with a 95% confidence interval (CI), using a restricted maximum likelihood model. Results From 197 publications screened, five studies fulfilled our criteria, comprising a total of 135 patients. Follow-up after ARNI therapy ranged from 12 to 27 months. No randomized clinical trials were found, and only two studies had a prospective design. Dextro-transposition of the great arteries (D-TGA) after atrial switch operation was the most common type of congenital heart disease with sRV (n=95; 70%). Meta-analysis demonstrates that ARNI reduced NT-proBNP levels during follow-up (EZ= -0.34, CI -0.59 to 0.08; p=0.01; I2=4.0%). Regarding RV function, ARNI improved RV fractional area change (RVFAC) (EZ= 0.75, CI 0.01 to 1.50; p= 0.048; I2=85.0%). A trend for RV global longitudinal strain improvement was also observed with ARNI (EZ= 1.74, CI -0.05 to 3.54; p=0.06; I2=95.9%) but not for tricuspid annular plane systolic excursion (EZ= -0.07, CI -0.33 to 0.20; p=0.62; I2=0.0%). RV diastolic diameter did not change significantly with ARNI (EZ= 0.07, CI -0.43 to 0.56; p=0.79; I2=68.2%). A trend for improvement on the 6-minute walk test was observed (EZ= 1.89, CI -0.13 to 3.91; p=0.07; I2=96.3%), but no effect on exercise oxygen consumption (VO2) (EZ= -0.09, CI -1.32 to 1.15; p=0.89; I2=91.4%). During follow-up ARNI did not change significantly systolic blood pressure (EZ= -0.32, CI -0.74 to 0.11; p=0.15; I2=58.4%) or serum creatinine (EZ= 0.23, CI -0.04 to 0.49; p=0.09; I2=0.0%). Conclusions Despite heterogeneity among these studies, this meta-analysis demonstrates that ARNI might improve NT-proBNP levels and RV function. ARNI seems safe and well tolerated, with no significant effect on blood pressure and renal function. More well-powered studies are needed to confirm the beneficial effects of ARNI in ACHD with sRV.

The impact of major infectious disease events and government relief packages on the film industry: evidence from Taiwan

This study focuses on the impact of COVID-19 on the film industry and the effectiveness of government relief policies. Taiwan was a region with a low level of infection at the beginning of the COVID-19 pandemic (2020), and the film industry could be maintained under government policies; therefore, this case study was conducted. Multiple regression models were used to explore the explanatory factors for movie box offices based on running size, production studios and countries, vacations, and the COVID-19 pandemic. The analysis covered a period from September 30, 2019, to September 27, 2020, encompassing a 52-week sample of 5686 films. The results indicated that weekly box office receipts (number of tickets sold) experienced a steep decline of more than 50% despite the implementation of various relief measures. While the number of locally produced films screened diminished significantly, the number of theatres, films, and rerun films and their market share increased substantially. This suggests that although the quantity of films remained stable during the pandemic, their quality or novelty did not correspondingly improve. Key findings from the regression models included the following: (1) there is a size effect (number of theaters screening the film) on the box office; (2) box offices decrease with the number of weeks since the opening week, and films from well-known producers and major studios, as well as products from the US, Japan, and Taiwan, can have positive effects on the box office; (3) student vacations have had a positive effect; and (4) the COVID-19 pandemic has had a negative effect.

Detection of biventricular volume increase in overweight and obese by using a novel index of the ideal human - a single center non-contrast-enhanced cardiac CT study

Abstract The bi-ventricular volume (BVV) can be measured from non-contrast-enhanced CT images in patients referred for coronary artery calcium (CAC) scoring. Such determined BVV has been found to correlate with left ventricular mass and to predict increased risk of all-cause and CV mortality in patients with type 2 diabetes mellitus. Currently, no data are available that quantifying the effect of body size on BVV using NCE-CT. We used a new indexing parameter that consisted of two parts: height and the difference between numerical values of height and body surface area (BSA). In the "ideal human", the difference is zero. Any deviation from this value determines the share of body mass regardless of height. Aim We hypothesize that a novel indexation way allows for better discrimination of the increased bi-ventricular volume in overweight and obese patients. Method We retrospectively analyzed the CT data from 2466 patients with CAC scoring over the last 15 years. Among them 1606 women and 860 men with an average age of 64 ± 11 years (range 21-93). The fatless bi-ventricular volume was measured manually using commercial software on a dedicated workstation (Vitrea2). Values of the raw (measured, ml) BVV and BVV normalized for height, BSA, and the novel parameter i.e. [h+ (h-BSA)], were compared in patients taking into account body mass index (BMI) categories of normal weight (25% of patients), overweight (40%) and obese (35%). Results Overall, the measured BVV [ml] was significantly greater in males (414±97) than in females (297±66) (p<0.001). BVV decreased non-linearly from before 40ties to mid-60ties, and then remained nearly stable. In normal-weight males, the measured BVV (370±80ml) was greater than in normal-weight females (279±61ml) (p<0.001). In overweight males, the BVV was 411±89ml; in overweight females, the BVV reached 290±59ml (p<0.001). These differences were non-significantly different from the sample of patients with normal BMI. In obese patients, mean values significantly differed between males and females (442±106 vs 321±71 ml, p<0.001). As the absolute value of the BVV should be interpreted in the context of body habitus, normalization for height, BSA, and the novel index were used. The results of these examinations are given in the figure. Conclusions Commonly used methods of indexing the volumetric parameters of the ventricles, as well as the novel indexing approach showed similar results in patients with normal body weight. The proposed indexation allowed for discriminating the increase in BVV that is easy to overlook in overweight. The use of body surface area for volumetric normalization is misleading as it provides similar values in normal, overweight, and obese patients, and should therefore be avoided. We should consider whether ventricular size standards based on a study population under 50 years of age create reliable conditions for detecting ventricular enlargement at an older age.

Efficacies of different treatment strategies for infants hospitalized with acute bronchiolitis.

: Acute bronchiolitis is a common cause of hospitalization during infancy that carries significant morbidity and mortality rates. : This study compared the efficacy of different treatment modalities for infants with bronchiolitis in terms of hospital stay and clinical severity scores. : The PubMed database was searched for re- levant studies. Eligibility criteria included double-blind randomized controlled trial design, assessment of the effect of treatment on bronchiolitis in infants under 2 years of age, and publication in English from inception through July 31, 2020. The primary efficacy outcome was the length of hospital stay, while the secondary outcome was the clinical severity score. The standardized treatment effect and standard error of the effect size were calculated. : We identified 45 randomized controlled trials of 24 pairwise comparisons. These 45 trials included 5,061 participants and investigated 13 types of interventions (12 active, 1 placebo). Inhalation therapy with epinephrine (standard mean difference [SMD], -0.41; 95% confidence interval [CI], -0.8 to -0.03) and hypertonic saline (SMD, -0.29; 95% CI, -0.55 to -0.03) reduced the length of hospital stay compared with normal saline. Hypertonic saline was the most effective at improving the clinical severity score (SMD, -0.52; 95% CI, -0.95 to -0.10). : Inhalation therapy with epinephrine and hypertonic saline reduced the length of hospital stay and the clinical severity of bronchiolitis among infants under 2 years of age.

Shining light on the shadows: The role of corruption control in the relationship between board composition and SDG disclosure

AbstractThis paper investigates how corruption control moderates the relationship between board composition and Sustainable Development Goals (SDG) disclosure. We analyze a sample of 269 companies from Mediterranean capitalism countries (Portugal, Greece, Italy, Spain, Malta, and Cyprus) combining a symmetric method (panel data analysis) and an asymmetric approach (fuzzy‐set qualitative comparative analysis). Our findings show that larger boards enhance SDG disclosure and female presence negatively impacts SDG disclosure. Corruption control is a driver of SDG disclosure, and the effect of board size on SDG disclosure is greater when companies are operating in countries with low rates of corruption. This the first paper that investigates the relationship between board composition and SDG disclosure, highlighting the moderating effect of controlling corruption at the country level. Managers should be aware that some board characteristics drive greater SDG disclosure. Additionally, governments can support SDG disclosure by combating corrupt practices in their countries, and by creating support mechanisms for companies to incorporate SDGs into business strategies.

Evaluation of the Applicability of Waste Rubber in Insulation Panels with Regard to Its Grain Size and Panel Thickness

This paper explores the effect of waste rubber grain size on the porosity, modulus of elasticity, thermal properties, and soundproofing performance of polymer composites with different thicknesses (10, 15, and 20 mm). All properties were tested in accordance with European standards, with the exception of porosity, which was measured using Archimedes’ principle. The findings indicate that with a consistent amount of polyurethane glue, finer rubber grains result in composites with higher porosity, leading to a lower modulus of elasticity but enhanced thermal and sound insulation. In contrast, coarser rubber grains produced composites with lower porosity and a higher modulus of elasticity, though with slightly reduced thermal insulation and significantly worse soundproofing. A combination of fine and coarse rubber grains provided a balanced performance, offering both good thermal and sound insulation while maintaining a high modulus of elasticity. Among the thicknesses tested, 15 mm was identified as optimal, combining a relatively high modulus of elasticity, low thermal conductivity, and better airborne sound insulation index. Future research will focus on applying this composite in concrete building products that meet noise protection and energy efficiency standards.

A systematic review and meta-analysis of health-related quality of life (HRQoL) outcomes in randomised controlled trials for pulmonary arterial hypertension (PAH)

Abstract Introduction ESC guidelines recognise the under use of disease-specific health-related quality of life (HRQoL) instruments. These include CAMPHOR, PAH-SYMPACT, Emphasis-10 and Living with Pulmonary Hypertension (LPH). Patients highly value HRQoL as a treatment outcome in PAH. This is the first meta-analysis to evaluate HRQoL instruments and outcomes in RCTs in pulmonary arterial hypertension (PAH). Purpose To evaluate which PAH-RCT interventions improve HRQoL outcomes and compare the suitability of HRQoL instruments used. Method We searched MEDLINE (Jan 1970 to Dec 2023) and Cochrane Library from Jan 1990 to Dec 2023 (EMBASE, CT.gov, ICTRP, CINAHL) for RCTs in PAH. Abstracts and unpublished studies were excluded and PRISMA reporting structure followed. Trials meeting final selection criteria included HRQoL instruments sufficiently powered to detect a minimal clinically important difference (MCID). Effective sample sizes were calculated in GPower3.1 from a two independent means model for 80% power, 5% significance, one-tailed test. Meta-analysis was performed in SPSSv28.1. Full search criteria are registered on PROSPERO (ID: CRD42024484021). Results After removal of duplicates, 896 records were screened, 43 studies included a HRQoL endpoint. 8 studies were included in the meta-analysis after exclusion for insufficient data (n=10) or power (n=25). 3 of these did not meet the MCID (>33m) for six-minute walk distance (6MWD) and evaluated separately to discriminate accuracy of HRQoL instrument. Instruments available for comparison were Short Form-36(SF-36), EuroQol (EQ-5D-5L) and Living with Pulmonary Hypertension (LPH). Studies not reaching MCID for 6MWD also showed no change in HRQoL (figure 1). Ambrisentan and exercise training demonstrate a significant improvement (p<0.05) in SF-36 physical(P) component (figure 2). This component was anchored to determine 6MWD MCID; other HRQoL values responded variably. Utility weighting to account for geographical variation was not reported with EQ-5D-5L and SF-36 in multicentre studies however AIR 2002 (Iloprost) was significant for both EQ-5D-5L instruments. The total component score of the disease-specific LPH was more sensitive to functional improvements and overall change in HRQoL compared to EQ-5D-5L (p<0.05). Conclusion Fewer than 10% of all RCTs in PAH have adequately considered a HRQoL outcome measure. 8 RCTs were powered to assess HRQoL. Iloprost, ambrisentan, riociguat and exercise training interventions demonstrate significant improvement in HRQoL. LPH was the only PAH-instrument powered to detect change. LPH was more sensitive to HRQoL than generic instruments and is multidimensional. Geographical indexing should be considered for generic instruments such as EQ-5D-5L and SF-36 in multicentre trials. As a highly valued outcome for patients, future studies should prioritise HRQoL as an endpoint.Figure 1Figure 2

Assessing magnetization and magnetic susceptibility of inverted core/shell spherical one-electron quantum dots: size and off-center displacement effects

Assessing magnetization and magnetic susceptibility of inverted core/shell spherical one-electron quantum dots: size and off-center displacement effects

Size effect of ZIF-8 based nanocarrier pesticide delivery system on targeted release and insecticidal activity.

Traditional chemical pesticides are easily lost by surface runoff and only small quantities reach the target, thus causing serious environmental pollution. In this work, dinotefuran@zeolitic imidazolate framework-8@polydopamine@zein (DNF@ZIF-8@PDA@zein), was constructed to deliver DNF with pH and enzyme double response of release, thereby achieving targeted release and efficient long-term pest control. DNF@ZIF-8@PDA@zein was synthesized with three hydrated diameters (249.73 ± 9.99 nm, 142.94 ± 5.63 nm and 75.16 ± 4.66 nm, respectively). The release of DNF from DNF@ZIF-8@PDA@zein after 28 h was significantly higher at pH 5.0 (89.22 ± 7.18%) compared to that at pH 8 (81.8 ± 6.11%). Protease-assisted release of DNF was notably higher than that without protease (pH 5: 89.22 ± 5.55% versus 27.19 ± 3.22%; pH 8: 81.8 ± 6.11% versus 25.39 ± 3.87%). The stimuli-responsive release of DNF from DNF@ZIF-8@PDA@zein increased with decreased particle size due to increased pore size, reduced binding forces (i.e., weaker π-π stacking, hydrogen bonding, and Zn-N covalent bonding), and the shortening of diffusion path, leading to faster disintegration and drug release. Additionally, the anti-photolysis ability of DNF@ZIF-8@PDA@zein was 3.2 times that of pure DNF. The insecticidal activity improved with smaller nanoparticles due to higher drug release rate and greater inhibition of detoxification enzyme activity by more zinc ion (Zn2+) dissolution. The pH and enzyme dual-responsive release as well as insecticidal activity of DNF@ZIF-8@PDA@zein increase with decreased nanoparticle size, showing effective pest management in long-term and potential application prospects in sustainable agriculture. © 2024 Society of Chemical Industry.

Anisotropic Fracture Evolution and Size Effect of the Fracture Process Zone in Laminated Shales Derived from Digital Image Correlation

Anisotropic Fracture Evolution and Size Effect of the Fracture Process Zone in Laminated Shales Derived from Digital Image Correlation

Fracture Analysis of 316L Specimens Fabricated via Material Extrusion Additive Manufacturing: Influence of Building Orientation and Notch Acuity

ABSTRACTThree‐point bending tests were performed on notched specimens extracted from cuboids of 316L stainless steel produced via material extrusion additive manufacturing. The cuboids were printed vertically and horizontally on the printing platform to account for the building orientation effect on the mechanical performance. For each orientation, three notch sizes were considered. Overall, the specimens printed with building direction parallel to the loading direction outperformed the others. A significant notch size effect was observed in these specimens since the sharpest notch provoked a decrease in the peak load reached by the specimens in comparison with larger notches. On the contrary, this effect was less relevant among the other specimens, which presented a conspicuous amount of residual porosity that contributed to the premature failure. Further investigations were carried out to correlate the building orientation to the density of the parts and, ultimately, to the investigated mechanical properties. The ASED and TCD criteria were also applied to assess their accuracy in the failure prediction of the tested specimens.

Response tests on the effects of particle size of waste glass sand and glass powder on the mechanical and durability performance of concrete

To investigate the effect of waste glass material particle sizes on the mechanical and durability properties of concrete, a two-phase experimental approach was conducted. First, comprehensive tests were performed to examine the effects of glass sand and glass powder of different particle sizes on concrete performance. Subsequently, based on the experimental results, an orthogonal test was designed to optimize the replacement amounts of composite particle sizes. The results indicated that an appropriate amount of glass sand can enhance the mechanical properties and durability of concrete, while excessive amounts or larger particle sizes may have adverse effects. The pozzolanic effect of glass powder also contributes to performance improvement, but the replacement rate should be limited to 20%. Under composite particle size conditions, the compressive, tensile, and shear strengths of concrete increased by 35.56%, 21.74%, and 13.79%, respectively, while durability significantly improved, with water absorption reduced by 20.73% and chloride ion permeability decreased by 63.10%. At a total replacement rate of 20%, the optimal proportions were determined to be 2.86% for 0.6 mm glass sand, 1.43% for 1.18 mm glass sand, 8.57% for 50–60 μm glass powder, and 7.14% for 60–70 μm glass powder. The incorporation of composite particle sizes improved the microstructure of concrete, thereby enhancing its mechanical and durability properties.

Characterizing local pig breeds as reservoirs for the domestic pig genetic variability worldwide via contributions to gene diversity and allelic richness.

Contributions to gene diversity and allelic richness were computed in a total of 2,260 domestic pig genotypes, sharing 53,626 autosomal SNPs, belonging to 98 pig subpopulations worldwide (41 Asian, 696 genotypes; 20 American, 262 genotypes; and 37 European, 686 genotypes), using 616 pig samples belonging to six different Cosmopolitan pig breeds as an outgroup, to ascertain if local pig subpopulation can be considered reservoirs of genetic diversity for the whole domestic pig species worldwide. Assessments were carried out for the whole dataset and separately for the American-European and Asian subsets. Effective population size was computed at the subpopulation level using molecular coancestry and linkage disequilibrium information to ensure that estimates of contributions to diversity were not affected by demographic issues. Most American and European pig subpopulations tended to have favorable contributions to both gene diversity and allelic richness. However, contributions to allelic richness were more consistent than those obtained for gene diversity, whether the computations are performed using either the whole dataset or the American-Asian subset, suggesting that allelic richness can be a key parameter to identify putative reservoirs for the species. The Asian pig subpopulations never contributed favorably to the allelic richness of the domestic pig metapopulation. Although these results can partially be explained by the highly divergent origins of the American-European and the Asian pig subpopulations, it cannot be discarded that the results obtained for the Asian subpopulations are biased due to a worse calling performance of the pig SNP arrays used for genotyping. The use of other potentially less biased sources of genotypic information is advisable to compare the Asian and American-European pig subpopulations genetic diversity.

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.

Influence of polypropylene fiber length and geometric shape on the compressive strength of cemented lepidolite tailings backfill

Lepidolite ore contains abundant lithium resources; however, the extraction process generates a large number of tailings, which are environmentally hazardous solid waste. Currently, cemented fiber reinforcement and tailings filling technologies are commonly used methods for tailings treatment. The fiber length and geometric shape significantly affect the performance of fiber-reinforced cemented lepidolite tailing backfill (CLTB). However, there is limited research on the impact of these two factors on the performance of CLTB. Consequently, Polypropylene fiber-reinforced CLTB of four sizes and four fiber lengths were prepared and used for uniaxial compressive strength (UCS) tests. The max UCS of fiber-reinforced CLTB was 2.84 MPa, and the maximum increase percent was 83.7% compared with the non-fiber-reinforced CLTB. The experimental results show that when the fiber length was 12 mm the CLTB had the maximum UCS, longer fibers did not necessarily result in a higher UCS. The end effect was significant when the difference in cross-sectional area was small. The UCS of the L-40 sample was higher than that of the Y-50 sample under the same fiber length. The differences in the size effect and geometric shape were the main factors influencing their mechanical performance. When the fiber length was from 0 mm to 6 mm, the size effect was obvious, the UCS values gradually decreased with an increase in the volume ratio and cross-sectional area. However, the fiber length was the primary factor influencing the fitting curve of the UCS when the fiber length was from 12 mm to 19 mm. Additionally, the addition of fibers enhanced the integrity of CLTB. In other words, fiber-reinforced CLTB exhibited improving structural integrity. This study can provide theoretical references for the research and practical applications of fiber-reinforced fillers and size effects, as well as the treatment of lepidolite tailings, while also reflecting the CLTB performance under the action of different sizes and different fiber lengths, improving the filling efficiency, mining, and backfill safety.

A Modified Debiased Inverse-Variance Weighted Estimator in Two-Sample Summary-Data Mendelian Randomization.

Mendelian randomization uses genetic variants as instrumental variables to estimate the causal effect of exposure on outcome from observational data. A common challenge in Mendelian randomization is that many genetic variants are only modestly or even weakly associated with the exposure of interest, a setting known as many weak instruments. Conventional methods, such as the popular inverse-variance weighted (IVW) estimator, could be heavily biased toward zero when the instrument strength is weak. To address this issue, the debiased IVW (dIVW) estimator and the penalized IVW (pIVW) estimator, which are shown to be robust to many weak instruments, were recently proposed. However, we find that the dIVW estimator tends to produce an exaggerated estimate of the causal effect, especially when the effective sample size is small. Although the pIVW estimator has better statistical properties, it is slightly more complex, and the idea behind this method is also a bit less intuitive. Therefore, we propose a modified debiased IVW (mdIVW) estimator that directly multiplies a shrinkage factor with the original dIVW estimator. After this simple modification, we prove that the mdIVW estimator not only has second-order bias with respect to the effective sample size, but also has smaller variance and mean squared error than the preceding two estimators. We then extend the proposed method to account for the presence of instrumental variable selection and balanced horizontal pleiotropy. We demonstrate the improvement of the mdIVW estimator over the competing ones through extensive simulation studies and real data analysis.

Study on the uniaxial tensile mechanical behavior of two-dimensional single-crystal aluminum nitride

Abstract To investigate the tensile behavior and mechanical properties of single-crystal aluminum nitride (AlN) at the microscopic level, molecular dynamics simulations were used to study the effects of crystal orientation, strain rate, environmental temperature, and hole defect size on fracture strength, fracture mechanism, and potential energy during uniaxial tensile. The results show that the tensile strength of AlN in the [100] crystal direction is stronger. The anisotropic behavior characteristics of Al-N bonds fracture mechanism, crack growth rate, and cracking degree are significant when stretched along the [100], [010], and [110] crystal directions. Under high temperature condition, the lattice structure undergoes changes, causing grain boundaries to move and slip. This facilitates the breaking of bonds, leading to a decrease in tensile strength and a reduction in stored potential energy. Hole defects cause more lattice damage, reducing the energy required for Al-N bonds breakage and facilitating the propagation of microcracks. Additionally, it was found that the strain rate affects the stress-strain behavior of the model. An increase in strain rate leads to an increase in breaking stress, and the rapid deformation of AlN results in more energy being stored in the lattice in the form of potential energy. Therefore, the tensile strength and potential energy are improved.