Local structure and medium-range ordering in relaxor ferroelectric Pb(Zn <inf>1/3</inf>Nb <inf>2/3</inf>)O <inf>3</inf> studied using neutron pair distribution function analysis

We studied an evolution of local structure and medium-range ordering in relaxor ferroelectric Pb(Zn 1/3Nb 2/3)O 3 (PZN) from 550 to 15 K using neutron pair distribution function analysis. We show that the local structure of PZN is distorted at all temperatures studied. With decreasing temperature, a medium-range ordering of local polarizations develops with no global rhombohedral phase transition below T M. Instead, the crystal structure can be described as a mixture of polar nanoregions in a disordered lattice, similar to the case of Pb(Mg 1/3Nb 2/3)O 3. © 2006 American Institute of Physics

Measurement of diffusion in articular cartilage using fluorescence correlation spectroscopy

<p>Abstract</p> <p>Background</p> <p>Fluorescence correlation spectroscopy (FCS) provides information about translational diffusion of fluorescent molecules in tiny detection volumes at the single-molecule level. In normal states, cartilage tissue lacks vascularity, so chondrocyte metabolism depends on diffusion for molecular exchanges. The abundant extracellular matrix (ECM) of cartilage is maintained by a limited number of chondrocytes. ECM plays an important role in the regulation of chondrocyte functions. In this study, FCS was used to measure diffusion behaviors of albumin, the major protein of the intra-articular space, using normal and degenerated cartilage. Preliminary investigation of fluorescence dyes including Alexa 488, Rhodamine 6G and Rhodamine 123 was conducted to evaluate their properties in cartilage.</p> <p>Results</p> <p>The results indicate that the diffusion behaviors of fluorescently lableded albumin can be observed using FCS in both normal and chemically degenerated cartilage.</p> <p>Conclusions</p> <p>This work demonstrates the capability of FCS for direct measurement of diffusion in cartilaginous ECM. When the diffusion characteristics of fluorescent probes in ECM are clarified using FCS evaluation, FCS will be applicable as a method for early diagnosis of osteoarthritis, which is accompanied by increased abnormalities of ECM and also as tool for evaluating bio-engineered artificial cartilage for autologous chondrocyte implantation.</p

Dynamic and Super-Personalized Media Ecosystem Driven by Generative AI: Unpredictable Plays Never Repeating The Same

This paper introduces a media service model that exploits artificial intelligence (AI) video generators at the receive end. This proposal deviates from the traditional multimedia ecosystem, completely relying on in-house production, by shifting part of the content creation onto the receiver. We bring a semantic process into the framework, allowing the distribution network to provide service elements that prompt the content generator, rather than distributing encoded data of fully finished programs. The service elements include fine-tailored text descriptions, lightweight image data of some objects, or application programming interfaces, comprehensively referred to as semantic sources, and the user terminal translates the received semantic data into video frames. Empowered by the random nature of generative AI, the users could then experience super-personalized services accordingly. The proposed idea incorporates the situations in which the user receives different service providers' element packages; a sequence of packages over time, or multiple packages at the same time. Given promised in-context coherence and content integrity, the combinatory dynamics will amplify the service diversity, allowing the users to always chance upon new experiences. This work particularly aims at short-form videos and advertisements, which the users would easily feel fatigued by seeing the same frame sequence every time. In those use cases, the content provider's role will be recast as scripting semantic sources, transformed from a thorough producer. Overall, this work explores a new form of media ecosystem facilitated by receiver-embedded generative models, featuring both random content dynamics and enhanced delivery efficiency simultaneously.Comment: 13 pages, 7 figure

Charge ordering, ferroelectric, and magnetic domains in LuFe2O4 observed by scanning probe microscopy

LuFe2O4 is a multiferroic system which exhibits charge order, ferroelectricity, and ferrimagnetism simultaneously below similar to 230 K. The ferroelectric/charge order domains of LuFe2O4 are imaged with both piezoresponse force microscopy (PFM) and electrostatic force microscopy (EFM), while the magnetic domains are characterized by magnetic force microscopy (MFM). Comparison of PFM and EFM results suggests that the proposed ferroelectricity in LuFe2O4 is not of usual displacive type but of electronic origin. Simultaneous characterization of ferroelectric/charge order and magnetic domains by EFM and MFM, respectively, on the same surface of LuFe2O4 reveals that both domains have irregular patterns of similar shape, but the length scales are quite different. The domain size is approximately 100 nm for the ferroelectric domains, while the magnetic domain size is much larger and gets as large as 1 mu m. We also demonstrate that the origin of the formation of irregular domains in LuFe2O4 is not extrinsic but intrinsic. (c) 2015 AIP Publishing LLC.open11116sciescopu

Adaptive Fuzzy Dynamic Surface Sliding Mode Position Control for a Robot Manipulator with Friction and Deadzone

Precise tracking positioning performance in the presence of both the deadzone and friction of a robot manipulator actuator is difficult to achieve by traditional control methodology without proper nonlinear compensation schemes. In this paper, we present a dynamic surface sliding mode control scheme combined with an adaptive fuzzy system, state observer, and parameter estimator to estimate the uncertainty, friction, and deadzone nonlinearities of a robot manipulator system. We design a dynamic surface sliding mode basic controller by systematic recursive design steps that yields several adaptive laws for the compensation of nonlinear friction, deadzone, and other unknown nonlinear dynamics. The boundedness and convergence of this closed-loop system are guaranteed by the Lyapunov stability theorem. Experiments on the Scorbot robot manipulator demonstrate the validity and effectiveness of the proposed control scheme