Results 61 to 70 of about 10,276,216 (240)

Remembrance and Reconciliation: Understanding the Little Rock Crisis of 1957 video recordings, 1997

, 1997
Collection contains nine videocassette tapes recording the public symposium, "Remembrance and Reconciliation: Understanding the Little Rock Crisis of 1957," held on 1997 September 26-27, at the University of Arkansas at Little Rock. Participants included:
University of Arkansas at Little Rock.
core  

Research the Surrounding Rock Pressure and Temperature Effect on the Rock‐Breaking Efficiency of TBM Cutter

In the process of rock breaking, the surrounding rock pressures exert a remarkable influence on the rock‐breaking efficiency of disc cutters. This study focuses on the rock‐breaking efficiency of tunnel breaking machine (TBM) disc cutters under varying ...
Tianyu Zhang, Peng Zhou, Zinan Wang, Xiaotong Ma, Jiacan Xu, Jianxu Shang   +5 more
core   +1 more source

Wood‐Derived Nanocellulose‐Biocarbon Fresnel‐Zone Plate Lenses for Sub‐THz Frequency Applications

Advanced Materials Technologies, EarlyView.
Wood‐derived nanocellulose and lignin‐based biocarbon were combined to fabricate fully bio‐based Fresnel zone plate (FZP) lenses for sub‐terahertz frequencies. These sustainable FZP lenses exhibit low dielectric loss and high directivity, achieving performance comparable to that of metallic references, and remain functional under environmental stress ...
Riikka Haataja, Mikko Kokkonen, Niina Halonen, Sami Myllymäki, Umair Rafique, Mandeep Singh, Ossi Laitinen, Heli Jantunen, Kristiina Oksman, Henrikki Liimatainen   +9 more
wiley   +1 more source

Numerical Simulation of Rock Breaking Mechanism for Compound Percussion Drilling

, 2019
: The ABAQUS dynamic impact module is used to establish the numerical calculation model for PDC single tooth-rock impact. The effects of PDC cutting teeth on the dynamic rock breaking mode and rock breaking effect under the combined action of rotating ...
Zhong, Su, Li, Yumei, Tao, Zhang, Yu, Liwei, Liu, Jianming   +4 more
core   +1 more source

O Radical‐Induced n‐to‐p Transition in PbS Quantum Dots Enabling Enhanced and Stable Photogating in QD/IGZO SWIR Phototransistors

Advanced Materials Technologies, EarlyView.
An O radical‐induced n‐to‐p transition in PbS quantum dots (QDs) is achieved via atmospheric Ar/O2 treatment, enabling favorable band alignment and stable photogating in PbS QD/IGZO phototransistors. Interfacial defect passivation and Fermi‐level modulation, confirmed by XPS and UPS analyses, effectively suppress dark current, induce a positive VTH ...
MD Redowan Mahmud Arnob, Solbee Lee, Hansol Jeong, Sabiqun Nahar, Jin Jang   +4 more
wiley   +1 more source

Collision‐Resilient Winged Drones Enabled by Tensegrity Structures

Advanced Robotics Research, EarlyView.
Based on structures of birds such as the woodpeck, this article presents the collision‐resilient aerial robot, SWIFT. SWIFT leverages tensegrity structures in the fuselage and wings which allow it to undergo large deformations in a crash, without sustaining damage. Experiments show that SWIFT can reduce impact forces by 70% over conventional structures.
Omar Aloui, Raphael Zufferey, William Stewart, Mohammad Askari, Simon Jeger, Dario Floreano   +5 more
wiley   +1 more source

Muscle Control of an Extra Robotic Digit

Advanced Robotics Research, EarlyView.
This study compares muscle‐ and movement‐based control for operating a supernumerary robotic thumb. While movement control performs better in the proposed tasks, muscle‐based (EMG) control promotes broader motor learning. The results highlight the promise and challenges of using biosignals for human augmentation, offering new insights into intuitive ...
Julien Russ, Lucy Dowdall, Francesco Cenciarelli, Kitty Goodridge, Mabel Ziman, Hristo Dimitrov, Danielle Clode, Tamar R. Makin   +7 more
wiley   +1 more source

Cross‐Scale Hierarchical Targeted Delivery System Based on Small‐Scale Magnetic Robots

Advanced Robotics Research, EarlyView.
This article reviews a cross‐scale hierarchical targeted delivery system that integrates magnetic continuum robots and magnetic microrobots. By combining rapid long‐range navigation with precise microscale targeting, the system overcomes key limitations of single‐scale approaches.
Junjian Zhou, Zhiqiang Chen, Yuanbiao Ma, Zhiqiang Tang, Qianqian Wang   +4 more
wiley   +1 more source

Analysis of Rock-Breaking Load Characteristics and Efficiency Optimization of Conical Cutterhead Hobs in Urban Hard-Rock SBM

Eng
To investigate the load characteristics and rock-breaking efficiency of the hobs on the conical cutterhead, a theoretical model of the hob’s rock-breaking load was established based on the plastic-brittle characteristics of rock, with a verification ...
Geqiang Li, Yunpeng Chen, Zhichong Qi, Dan Lyu, Shuai Wang, Zhenle Dong   +5 more
doaj   +1 more source

Rock-Breaking Mechanism of Special-shaped PDC Cutter in Heterogeneous Granite

Shiyou jixie, 2022
In order to clarify the rock-breaking mechanism of special-shaped PDC cutter in the difficult-to-drill formations(e.g. granite), the finite element method was used to establish a mesoscopic heterogeneous granite model with different mineral components ...
Liu Hexing, Luo Yunxu, Liu Weiji, Ma Chuanhua, Wu Yanhui, Zhu Xiaohua, Liu Yaya   +6 more
doaj