Optimizing Binding Site Spacing in Fluidic Self-Assembly for Enhanced Microchip Integration Density.

This manuscript presents a comprehensive study on the assembly of microchips using fluidic self-assembly (FSA) technology, with a focus on optimizing the spacing between binding sites to improve yield and assembly. Through a series of experiments, we explored the assembly of microchips on substrates with varying binding site spacings, revealing the impact of spacing on the rate of undesired chip assembly across multiple sites. Our findings indicate a significant reduction in incorrect assembly rates as the spacing increases beyond a critical threshold of 140 µm. This study delves into the mechanics of chip alignment within the fluid medium, hypothesizing that the extent of the alloy's grip on the chips at different spacings influences assembly outcomes. By analyzing cases of undesired assembly, we identified the relationship between binding site spacing and the area of chip contact, demonstrating a decrease in the combined left and right areas of chips as the spacing increases. The results highlight a critical spacing threshold, which, when optimized, could significantly enhance the efficiency and precision of microchip assembly processes using FSA technology. This research contributes to the field of microcomponent assembly, offering insights into achieving higher integration densities and precision in applications, such as microLED displays and augmented reality (AR) devices.

Predicting the Presence of Active Schools: A National Survey of School Principals in the United States.

BACKGROUND: Principals are key to the promotion of physical activity (PA) in schools. The purpose of this study was to understand how school principals' PA values, behaviors, and individual and school characteristics were associated with the presence of an active school. METHODS: A representative sample of 1019 school principals in the United States was surveyed. Survey items addressed principals' values and behaviors associated with PA, individual and school demographic factors, such as years of experience and school level, and a single item asking whether principals perceived their school to be an active school (ie, provides students with opportunities to be physically active before, during, and after the school day). Significant variables from a cross-tabulation and chi-square analysis were added to a hierarchical logistic regression model to assess the predictive properties of principal values and behaviors as they relate to the presence of an active school. RESULTS: Approximately half of principals (47%) reported having an active school. The model significantly predicted the presence of an active school but accounted for only 6.6% of the total variance. Although values toward PA and more frequent personal PA behaviors were associated with the presence of an active school within the cross-tabulation and chi-square analysis, neither variable emerged as a significant predictor in the regression model. CONCLUSIONS: Principals' personal PA values and behaviors contribute to the presence of an active school, but other variables, including years of experience and school contextual factors, are more powerful predictors.

Health-Related Fitness Levels among Title I Elementary School Students.

Over the past few decades, studies have emphasized improving children's health by increasing health-related fitness levels. Despite the known benefits of health-related fitness in youth, studies have also highlighted a lack of physical activity opportunities for children living in low-income households. The purpose of this study was to investigate the health-related fitness levels of students attending Title I (low-income) elementary schools. A total of 77 elementary students (50.6% female; Mage = 10.0, SD = 0.827) from two Title I elementary schools in the western United States completed the FitnessGram assessments of aerobic capacity, muscular strength and endurance, and flexibility. Descriptive statistics were used to identify the number of students in the Healthy Fitness Zone (HFZ) based upon the FitnessGram HFZ Performance Standards. Less than 17% of students achieved the HFZ for aerobic capacity and only 31.2% achieved the HFZ for upper body strength and endurance. Students performed better for abdominal strength and endurance and flexibility with 55.8% and 68.8% achieving the HFZ, respectively. The results of this study offer insights into the health-related fitness levels of a unique population, students attending Title I schools. School health professionals, including physical education teachers, need to be aware of existing disparities and make efforts to systematically intervene.

Numerical study on tsunami hazard mitigation using a submerged breakwater.

Most coastal structures have been built in surf zones to protect coastal areas. In general, the transformation of waves in the surf zone is quite complicated and numerous hazards to coastal communities may be associated with such phenomena. Therefore, the behavior of waves in the surf zone should be carefully analyzed and predicted. Furthermore, an accurate analysis of deformed waves around coastal structures is directly related to the construction of economically sound and safe coastal structures because wave height plays an important role in determining the weight and shape of a levee body or armoring material. In this study, a numerical model using a large eddy simulation is employed to predict the runup heights of nonlinear waves that passed a submerged structure in the surf zone. Reduced runup heights are also predicted, and their characteristics in terms of wave reflection, transmission, and dissipation coefficients are investigated.