Fabrication of GaN-Based White Light-Emitting Diodes on Yttrium Aluminum Garnet-Polydimethylsiloxane Flexible Substrates

This study concerns the characteristics of white GaN-based light-emitting diode (LED) on flexible substrates. The thin film GaN-based blue LEDs were directly transferred from sapphire onto the flexible polydimethylsiloxane (PDMS) substrates by laser lift-off (LLO) process. The PDMS substrates were incorporated 10–40% cerium doped yttrium aluminum garnet phosphor, YAG:Ce3+, and formed the GaN-based white LEDs. The white LEDs prepared by the GaN-based LEDs on the YAG-PDMS substrates reveal one peak at 470 nm corresponding to the emission of the GaN-based LED and a broadband included five weak peaks caused by YAG:Ce3+ phosphors

Multistage Infrastructure System Design: An Integrated Biofuel Supply Chain against Feedstock Seasonality and Uncertainty

A biofuel supply chain consists of various interdependent components from feedstock resources all the way to energy demand sites. This study focuses on the design of an efficient biofuel supply chain system against seasonal variations and uncertainties of feedstock supply in an integrative manner. By integrating planning and operational decisions in a stochastic programming framework, we aim at finding an effective design strategy for biofuel supply chain that is economically viable and hedges well against a wide range of future uncertainties. A solution algorithm based on scenario decomposition is designed to overcome computational challenges involved in large-scale applications. A California case study is implemented to demonstrate the applicability of the proposed methods in evaluating the economic potential, the infrastructure needs, and the risk of wastes-based bioethanol production

A Comparative Study on Spin-Orbit Torque Efficiencies from W/ferromagnetic and W/ferrimagnetic Heterostructures

It has been shown that W in its resistive form possesses the largest spin-Hall ratio among all heavy transition metals, which makes it a good candidate for generating efficient dampinglike spin-orbit torque (DL-SOT) acting upon adjacent ferromagnetic or ferrimagnetic (FM) layer. Here we provide a systematic study on the spin transport properties of W/FM magnetic heterostructures with the FM layer being ferromagnetic Co$_{20}$Fe$_{60}$B$_{20}$ or ferrimagnetic Co$_{63}$Tb$_{37}$ with perpendicular magnetic anisotropy. The DL-SOT efficiency $|\xi_{DL}|$, which is characterized by a current-induced hysteresis loop shift method, is found to be correlated to the microstructure of W buffer layer in both W/Co$_{20}$Fe$_{60}$B$_{20}$ and W/Co$_{63}$Tb$_{37}$ systems. Maximum values of $|\xi_{DL}|\approx 0.144$ and $|\xi_{DL}|\approx 0.116$ are achieved when the W layer is partially amorphous in the W/Co$_{20}$Fe$_{60}$B$_{20}$ and W/Co$_{63}$Tb$_{37}$ heterostructures, respectively. Our results suggest that the spin Hall effect from resistive phase of W can be utilized to effectively control both ferromagnetic and ferrimagnetic layers through a DL-SOT mechanism

Correlation between Pineal Activation and Religious Meditation Observed by Functional Magnetic Resonance Imaging

The human brain possesses plenty of functions but little is known about its scientific relationship with mind and spirit. Conferences^1,2^ focused on the connection between science and religion were held very recently in which neuroscientists, Buddhist scholars and Dalai Lama discussed attention, mental imagery, emotion, mind, brain functions and meditation, suggesting religious meditation offers an effective means to investigate the mystery of mind and spirit. In the past decade, scientists struggled to obtain brain mappings for various meditation styles using different brain imaging techniques and stimulating results have been observed^3-17^. In this letter we report that, together with other brain regions, pineal body exhibit significant activation during meditation process, supporting the long lasting speculation that pineal plays an important role in the intrinsic awareness which might concern spirit or soul. Pineal is known as an endocrine organ which produces substrates including melatonin and has been ascribed numerous even mysterious functions but its activation during meditation has never been observed by brain imaging technique. In seventeenth century, based on anatomic observation, Descartes ventured to suggest that pineal serves as the principal seat of the soul^18-20^. Inspired by its geometric center in the brain, physiologists, psychologists, philosophers and religionists have been speculating for centuries about pineal's function relevant to spirit and soul. In this study, we chose Chinese Original Quiet Sitting, one style of meditation, to explore this long lasting speculation by functional magnetic resonance imaging technique. Our results demonstrate a correlation between pineal activation and religious meditation which might have profound implications in physiological understanding of the intrinsic awareness

Speech Dereverberation Based on Integrated Deep and Ensemble Learning Algorithm

Reverberation, which is generally caused by sound reflections from walls, ceilings, and floors, can result in severe performance degradation of acoustic applications. Due to a complicated combination of attenuation and time-delay effects, the reverberation property is difficult to characterize, and it remains a challenging task to effectively retrieve the anechoic speech signals from reverberation ones. In the present study, we proposed a novel integrated deep and ensemble learning algorithm (IDEA) for speech dereverberation. The IDEA consists of offline and online phases. In the offline phase, we train multiple dereverberation models, each aiming to precisely dereverb speech signals in a particular acoustic environment; then a unified fusion function is estimated that aims to integrate the information of multiple dereverberation models. In the online phase, an input utterance is first processed by each of the dereverberation models. The outputs of all models are integrated accordingly to generate the final anechoic signal. We evaluated the IDEA on designed acoustic environments, including both matched and mismatched conditions of the training and testing data. Experimental results confirm that the proposed IDEA outperforms single deep-neural-network-based dereverberation model with the same model architecture and training data

Densification Behavior, Microstructure, and Property of ZnO with Multi-Oxides Glass Addition at Different Sintering Temperatures

Zinc Oxide (ZnO) mixed with various amount of glasses were sintered at different temperatures. The densification behavior of zinc oxide with glass addition and its microstructure and dielectric constant sintered from 900° to 1200°C have been investigated. A unique glass composition contained GeO2, MoO3, and V2O5 (GMV) was designed to act as the sintering aid to enhance the densification and to adjust the dielectric constant of ZnO. The effect of sintering temperature on the densification behavior and dielectrics properties of ZnO was investigated by dilatometer, x-ray diffractometer, scanning electron microscopy and LCR meter.  The glass additive formed a thin continuous liquid phase and rearranged ZnO particles into a dense microstructure at relatively low temperature. The dielectric constants of glass added ZnO ceramics were found to vary with the glass concentration and sintering temperature