An investigation of practices to address the disproportionate representation of African American students in special education programs in Virginia

The purpose of this study was to determine the extent to which practices to address disproportionality suggested by the professional literature are being implemented in Virginia public schools. It also sought to understand the perceptions of special education directors regarding the effectiveness of these practices in addressing disproportionality. Mixed methods were employed through the use of a survey instrument which was developed for this study and a content analysis of school division action plans.;There were two overarching research focus questions as well as six corresponding sub-questions investigated in this study. This study included 111 directors of special education who represent each of the eight regional study groups.;The findings from this study indicate that practices suggested in the professional literature are being widely used in Virginia public schools. as well, all of the practices stated in the survey are largely perceived to be effective in addressing the issue of disproportionality.;Through the content analysis of eleven school division actions plans and the analysis of the open-ended survey question, additional practices being used to address disproportionality emerged. The results of the study also indicated a significant positive relationship between division size, proportion of African American students enrolled, and proportion of African American students with disabilities and implementation of the practices and perceived effectiveness. Recommendations for future research as well as implications for general and special education leaders are discussed

Fibrillar Elastomeric Micropatterns Create Tunable Adhesion Even to Rough Surfaces

Acknowledgements V.B., N.K.G., and E.A. contributed with conception and experimental design. V.B. performed the experiments. V.B., R.H., A.G., and R.M.M. carried out analysis and interpretation of data. V.B., R.H., A.G., and E.A. wrote the manuscript. V.B. and R.H. contributed equally to this work. V.B. acknowledges funding by SPP 1420 of the German Science Foundation DFG. E.A., N.K.G., and R.H. acknowledge funding from the European Research Council under the European Union/ERC Advanced Grant “Switch2Stick,” Agreement No. 340929.Peer reviewedPublisher PD

Efficient table-top dual-wavelength beamline for ultrafast transient absorption spectroscopy in the soft X-ray region.

We present a table-top beamline providing a soft X-ray supercontinuum extending up to 370 eV from high-order harmonic generation with sub-13 fs 1300 nm driving pulses and simultaneous production of sub-5 fs pulses centered at 800 nm. Optimization of high harmonic generation in a long and dense gas medium yields a photon flux of  ~ 1.4 × 106 photons/s/1% bandwidth at 300 eV. The temporal resolution of X-ray transient absorption experiments with this beamline is measured to be 11 fs for 800 nm excitation. This dual-wavelength approach, combined with high flux and high spectral and temporal resolution soft X-ray absorption spectroscopy, is a new route to the study of ultrafast electronic dynamics in carbon-containing molecules and materials at the carbon K-edge

Experimental Aspects of Highly Accelerated Life Tests

Experimental aspects of High Accelerated Life Tests (HALT) are presented. A statistical analysis of test results which allows to define the different characteristic areas of a product (operating and destruction limits) is given. In particular, some tests on electronic board using thermal and vibration stresses have been investigated

Multi-Response Optimization For Industrial Processes

Process optimization is a very important point in modern industry. There are many classical optimization methods, which can be applied when some mathematical conditions are verified. Real situations are not very simple so that classical methods may not succeed in optimizing; as in cases when the optimization has several contradictory objectives (Collette, 2002). The purpose of this work is to propose an optimization method for industrial processes with multiple inputs and multiple outputs (MIMO), for which the optimization objectives are generally contradictory and for which some objectives are not maximum or minimum but performance criteria. The first step of this method is modeling each process response by a quadratic model. After establishing the model, we use a simplified numerical optimization algorithm in order to determine values of the parameters allowing optimizing the different responses, for MIMO processes. This method will also allow finding optimum target values for multiple inputs single output processes

Composition-Dependent Passivation Efficiency at the CdS/CuIn1-xGaxSe2 Interface

International audienc

Evaluating the predicted reliability of mechatronic systems: state of the art

Reliability analysis of mechatronic systems is a recent field and a dynamic branch of research. It is addressed whenever there is a need for reliable, available, and safe systems. The studies of reliability must be conducted earlier during the design phase, in order to reduce costs and the number of prototypes required in the validation of the system. The process of reliability is then deployed throughout the full cycle of development. This process is broken down into three major phases: the predictive reliability, the experimental reliability and operational reliability. The main objective of this article is a kind of portrayal of the various studies enabling a noteworthy mastery of the predictive reliability. The weak points are highlighted. Presenting an overview of all the quantitative and qualitative approaches concerned with modelling and evaluating the prediction of reliability is so important for future reliability studies and for academic research to come up with new methods and tools. The mechatronic system is a hybrid system, it is dynamic, reconfigurable, and interactive. The modeling carried out of reliability prediction must take into account these criteria. Several methodologies have been developed in this track of research. In this regard, the aforementioned methodologies will be analytically sketched in this paper.Comment: 13 page, Mechanical Engineering: An International Journal (MEIJ), Vol. 3, No. 2, May 201

Prise en compte des interactions multi-domaines lors de l’évaluation de la fiabilité prévisionnelle des systèmes mécatroniques

The mechatronic systems are hybrid, dynamic, interactive and reconfigurable. Therefore their dysfunctional modeling is very difficult. Multi-physical interactions between components have impacts on the degradation or on system failures, leading thus to more uncertainty in reliability evaluation. The work presented in this paper aims to improve the integration of multi-domain interactions in the reliability assessment of mechatronic systems. After a presentation of the state of the art of mechatronic systems reliability estimation methods, we propose to represent multi domain interactions by influential factors in the dysfunctional model. We generally use proportional hazard models; in the case of an interaction represented by a temperature stress, Arrhenius model is used