Optical phase conjugation with less than a photon per degree of freedom

We demonstrate experimentally that optical phase conjugation can be used to focus light through strongly scattering media even when far less than a photon per optical degree of freedom is detected. We found that the best achievable intensity contrast is equal to the total number of detected photons, as long as the resolution of the system is high enough. Our results demonstrate that phase conjugation can be used even when the photon budget is extremely low, such as in high-speed focusing through dynamic media, or imaging deep inside tissue

Prediction of vertical bearing capacity of waveform micropile

This study proposes a predictive equation for bearing capacity considering the behaviour characteristics of a waveform micropile that can enhance the bearing capacity of a conventional micropile. The bearing capacity of the waveform micropile was analysed by a three-dimensional numerical model with soil and pile conditions obtained from the field and centrifuge tests. The load-transfer mechanism of the waveform micropile was revealed by the numerical analyses, and a new predictive equation for the bearing capacity was proposed. The bearing capacities of the waveform micropile calculated by the new equation were comparable with those measured from the field and centrifuge tests. This validated a prediction potential of the new equation for bearing capacity of waveform micropiles

Being Prepared and Staying Connected: Scouting’s Influence on Social Capital and Community Involvement

Objectives In recent years, scholars have become concerned about the effects that declining levels of social capital are having on community life in the United States. Data suggest that Americans are less likely to interact with neighbors and less likely to participate in community groups than they were in the past. Nevertheless, researchers have found that participation in some types of organizations has a positive impact on social capital and civic involvement. Each year, millions of American youth participate in programs designed to promote positive youth development. Here, we examine the effect that participation in one of the largest youth organizations, the Boy Scouts of America (BSA), has on adult social capital and community involvement. Methods Utilizing a national survey of adult males, we compare measures of social capital and community involvement for former Scouts and non‐Scouts. Results Our findings suggest that level of involvement in the Boy Scouts is significantly related to measures of adult social capital and community engagement. Conclusion Scouting tends to have a significant impact on the lives of its most committed members. Future research must continue to explore the long‐term effects of participation in youth organizations

Study on the global well-posedness for the two-dimensional Boussinesq and Lans-alpha magnetohydrodynamics equations

We investigate the global (in time) regularity problem for two different models; generalized two-dimensional Boussinesq and Lans-alpha magnetohydrodynamics system. First, the global regularity of 2D incompressible generalized Euler-Boussinesq equations has been studied. We establish the global existence and uniqueness of solutions to the initial-value problem when the velocity field is "double logarithmically" more singular than the one given by the Biot-Savart law. This global regularity result goes beyond the critical case. Secondly, we consider the two-dimensional Navier-Stokes-Boussinesq equations with logarithmically super-critical dissipation. By implementing Besov space technique, the global well-posedness of initial value problem is established. These results improve the existing results of super-critical Boussinesq system of equations. Finally, we study the two-dimensional generalized Lans-alpha magnetohydrodynamics system. We mainly focus on Lans-alpha magnetohydrodynamics system of equations with logarithmically weaker dissipation than full dissipation together with zero diffusion or zero dissipation and logarithmically weaker diffusion than full diffusion. In both cases, we are successful to resolve global regularity issues