gebhart/patrepeval huggingface dataset:
Temperature-Dependent Properties of a 1–3 Connectivity Piezoelectric Ceramic–Polymer Composite (2015)

Abstract In this work, the 1–3 connectivity piezoelectric ceramic–polymer composites have been fabricated by a viscous-polymer processing, where 0.90Pb(Zr 0.52 Ti 0.48 )O 3 –0.05Pb(Mn 1/3 Sb 2/3 )O 3 –0.05Pb(Zn 1/3 Nb 2/3 )O 3 (PZT–PMS–PZN) fibers with 0.5 volume fraction were aligned in epoxy matrix. The sintered PZT fibers, with average diameter of 300 μm and aspect ratio (height/diameter) higher than 3, all showed a pure perovskite phase structure and highly dense morphology. The dielectric, piezoelectric, ferroelectric properties and the vibration modes of the 1–3 composites were measured and demonstrated in comparison with that of the monolithic piezoelectric ceramics. The results confirmed that the 1–3 composites possessed a low acoustic impedance ( Z ) of 13 MRayl and a high thickness coupling coefficient ( k t ) of 0.59, in addition, only single thickness vibration mode with the resonance frequency over 1.5 MHz was observed. With temperature elevation, the properties including dielectric constant ε r , k t , the ratio of k t to k p ( k t / k p ) and the acoustic impedance ( Z ) increase, while the planar electromechanical coupling coefficient ( k p ) show opposite temperature dependence. Under test temperature of 100°C, the 1–3 composites still present excellent temperature stability with increased k t / k p ratio up to 3.6. The researches on temperature-dependent properties of the 1–3 composites are critical for improving its applications in various environments.
Further studies on the prognostic importance of barr body frequency in human breast cancer: With discussion on its probable mechanism (1980)

Based on the Barr body frequency, a total of 285 unselected breast cancer tissues were categorised as negative and positive tumours; incidence of these two groups in our series was 2:1, respectively. When 2-years' disease-free interval and 10-years' survival were considered, it was seen that patients harbouring negative tumours had significantly early recurrence and shorter duration of survival as compared to those having positive tumours. As vascular spread is the prerequisite of early recurrence, the shorter survival in the patients having negative tumours could be explained on the basis of blood vessel invasion, in that 73% of the negative tumours had blood vessel invasion, in contrast to only 24% in the positive tumours.
The Role of miR-29a in the Regulation, Function, and Signaling of Liver Fibrosis (2018)

Both fibrosis and cirrhosis of the liver are the end results of most kinds of chronic liver damage and represent a common but difficult clinical challenge throughout the world. The inhibition of the fibrogenic, proliferative, and migratory effects of hepatic stellate cells (HSCs) has become an experimental therapy for preventing and even reversing hepatic fibrosis. Furthermore, a complete understanding of the function of non-coding RNA-mediated epigenetic mechanisms in HSC activation may improve our perception of liver fibrosis pathogenesis. This review focuses on the evolving view of the molecular mechanisms by which HSC activation by miR-29a signaling may moderate the profibrogenic phenotype of these cells, thus supporting the use of miR-29a agonists as a potential therapy for treating liver fibrosis in the future.
Large scale molecular simulations with application to polymers and nano-scale materials (2009)

There remain practical problems to predicting structures and properties of materials from first principles, though the foundation, quantum mechanics, has been established for many years. The goals of this research are to develop methods and tools that are accurate and practical, and apply them to important problems. Two aspects of the methodology are focused. 1. The development of accurate force fields based on ab initio quantum mechanical calculations on prototype systems. Procedures were developed on polyvinyl chloride (PVC) and successfully applied on other types of polymers. They are very important to studying of amorphous polymers materials, for which current methods have not been useful in predicting important properties (e.g. moduli and glass temperature). 2. The development of Massive Parallel Simulation (MPSim) Software. MPSim is suitable for large systems (millions of atoms). It has the ability of including environmental variables (temperature, pressure, tension, and shear) and extracting physical properties (moduli and glass temperatures). The theories and algorithms implemented are summarized in the Appendix. These methods and tools are applied to the accurate simulation of structures and properties of amorphous polymer materials and nano-materials. Molecular dynamics (MD) simulation on polyethylene (chapter 6) was used to develop a general strategy for predicting glass transition temperatures which is expected to be very important in polymer industry. In chapter 7, these strategies were successfully applied to three important fluoro polymers. Single-walled carbon nanotubes (SWNT), recently discovered but not very well characterized, is an interesting new class of materials. Using an accurate force field, structures and mechanical properties of these systems are studied. Chapter 2 shows that the dominating factor for deciding stable structures and mechanical properties is the tube size, not chirality. The behavior of (10, 10) nano-tube under bending are studied (chapter 3) based on energy of hypothetical toroids with different radii. Yielding curvature of 1/R_s (R_s = 183.3 (Å)) where elastic bending becomes plastic response is found. In chapter 4, closest packing of K_5C_(80) with the distribution of K atoms along tube surface similar to the stacking of stage one K_1C_8 is established as the optimum structure of K-doped SWNT crystal.
Substituent effects on the physical properties and p<i>K</i><sub><i>a</i></sub> of phenol (2001)

Abstract Substituent effects on the physical properties and p K a of phenol were studied using density functional theory [B3LYP/6‐311G(d,p)] calculations. Substituents alter the physical properties of phenol such as the hydroxyl‐group CO and OH bond lengths, the C OH bond angle, and the energy barrier to rotation about the C O bond, and also influence the hydroxyl‐group p K a . Except for the rotational barrier, Hammett σ constants showed strong correlation with these property changes. Several quantum chemical parameters, including the natural charge on the phenolic hydrogen Q n (H) and the natural charge on the phenoxide oxygen Q n (O − ), the HF/6‐311G(d,p) HOMO energy E homo , and the proton‐transfer energy Δ E prot , outperformed the empirical Hammett constants in modeling changes in the p K a . All of these latter parameters yielded correlation coefficients ∣ r ∣>0.94 for the p K a . © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001
A multimedia storage system for on-demand playback (1995)

This paper presents the design of a multimedia storage system for on-demand playback. The design stresses effective utilization of disk bandwidth with minimal data buffer to minimize overall system costs. The design procedure is most distinctive in the following two aspects: it bases on a tight upper bound of the lumped disk seek time for the Scan disk scheduling algorithm to achieve effective utilization of the disk bandwidth; and it starts with a general two-level hierarchical disk array structure to derive the optimal configuration for specific requirements.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Wear and corrosion properties of low-cost eggshell-reinforced green AZ91 matrix composites (2022)

The present work deals with the production of economical, recyclable and low-weight magnesium matrix composites with waste eggshell (ES). AZ91 magnesium matrix eggshell reinforced composites were fabricated by the powder metallurgy method, and their tribological and corrosion performances were investigated under different test conditions. Results showed that ES enhanced the microhardness value of unreinforced alloy up to 20.4%. Uniform distribution of eggshell particles in the matrix was achieved according to the microstructural investigations. Eggshell reinforcement exhibited a good lubricant effect and developed wear behaviour in almost all test conditions. When 5 wt-% eggshell was added to the alloy, 36.4 wt-% improvement of wear performance was achieved under the load of 20 N at 100 mm s−1 sliding speed. When the reinforcement content was increased, the corrosion rate began to accelerate. The corrosion rate increased almost four times as the reinforcement ratio increased at low pH values. The design of test conditions and the analysis of output responses were studied by the statistical analysis of Taguchi and analysis of variance (ANOVA). ANOVA indicated that the wear rate and corrosion rate were mainly affected by load (52.7%) and pH (21.7%), respectively.
How does the G protein, G<sub>i2</sub>, transduce mitogenic signals? (1994)

Serpentine receptors coupled to the heterotrimeric G protein, Gi2, are capable of stimulating DNA synthesis in a variety of cell types. A common feature of the Gi2-coupled stimulation of DNA synthesis is the activation of the mitogen-activated protein kinases (MAPKs). The regulation of MAPK activation by the Gi2-coupled thrombin and acetylcholine muscarinic M2 receptors occurs by a sequential activation of a network of protein kinases. The MAPK kinase (MEK) which phosphorylates and activates MAPK is also activated by phosphorylation. MEK is phosphorylated and activated by either Raf or MEK kinase (MEKK). Thus, Raf and MEKK converge at MEK to regulate MAPK. Gi2-coupled receptors are capable of activating MEK and MAPK by Raf-dependent and Raf-independent mechanisms. Pertussis toxin catalyzed ADP-ribosylation of alpha i2 inhibits both the Raf-dependent and -independent pathways activated by Gi2-coupled receptors. The Raf-dependent pathway involves Ras activation, while the Raf-independent activation of MEK and MAPK does not involve Ras. The Raf-independent activation of MEK and MAPK most likely involves the activation of MEKK. The vertebrate MEKK is homologous to the Ste11 and Byr2 protein kinases in the yeast Saccharomyces cerevisiae and Schizosaccharomyces pombe, respectively. The yeast Ste11 and Byr2 protein kinases are involved in signal transduction cascades initiated by pheromone receptors having a 7 membrane spanning serpentine structure coupled to G proteins. MEKK appears to be conserved in the regulation of G protein-coupled signal pathways in yeast and vertebrates. Raf represents a divergence in vertebrates from the yeast pheromone-responsive protein kinase system.(ABSTRACT TRUNCATED AT 250 WORDS)
Application of mobile vehicle lidar for urban air pollution monitoring (2016)

A mobile vehicle lidar system has been developed and applied to detect urban air quality. On September 21 and 22, 2015, particulate matter observation with mobile vehicle lidar was carried out in the Binhai New Area of Tianjin. Combined with the latitude and longitude information acquired by a GPS, the three-dimensional distribution of the aerosol extinction coefficient was presented in the experimental area. Furthermore, the source, distribution, and the transportation path of the aerosols in the area were investigated based on lidar data, local meteorological data, and backward trajectory analysis. The results show that mobile vehicle lidar can detect the atmospheric aerosols and reflect the stereoscopic distribution properties of aerosols. The potential of this vehicle lidar system provides a new scientific basis for the study of the source, distribution, and transportation of atmospheric particles.
Fog-Driven Context-Aware Architecture for Node Discovery and Energy Saving Strategy for Internet of Things Environments (2019)

The consolidation of the Fog Computing paradigm and the ever-increasing diffusion of Internet of Things (IoT) and smart objects are paving the way toward new integrated solutions to efficiently provide services via short-mid range wireless connectivity. Being the most of the nodes mobile, the node discovery process assumes a crucial role for service seekers and providers, especially in IoT-fog environments where most of the devices run on battery. This paper proposes an original model and a fog-driven architecture for efficient node discovery in IoT environments. Our novel architecture exploits the location awareness provided by the fog paradigm to significantly reduce the power drain of the default baseline IoT discovery process. To this purpose, we propose a deterministic and competitive adaptive strategy to dynamically adjust our energy-saving techniques by deciding when to switch BLE interfaces ON/OFF based on the expected frequency of node approaching. Finally, the paper presents a thorough performance assessment that confirms the applicability of the proposed solution in several different applications scenarios. This evaluation aims also to highlight the impact of the nodes' dynamic arrival on discovery process performance.
Control of crystallographic texture and surface morphology of Pt/Tio<sub>2</sub> templates for enhanced PZT thin film texture (2015)

Optimized processing conditions for Pt/TiO2/SiO2/Si templating electrodes were investigated. These electrodes are used to obtain [111] textured thin film lead zirconate titanate (Pb[ZrxTi1-x ]O3 0 ≤ x ≤ 1) (PZT). Titanium deposited by dc magnetron sputtering yields [0001] texture on a thermally oxidized Si wafer. It was found that by optimizing deposition time, pressure, power, and the chamber pre-conditioning, the Ti texture could be maximized while maintaining low surface roughness. When oxidized, titanium yields [100]-oriented rutile. This seed layer has as low as a 4.6% lattice mismatch with [111] Pt; thus, it is possible to achieve strongly oriented [111] Pt. The quality of the orientation and surface roughness of the TiO2 and the Ti directly affect the achievable Pt texture and surface morphology. A transition between optimal crystallographic texture and the smoothest templating surface occurs at approximately 30 nm of original Ti thickness (45 nm TiO2). This corresponds to 0.5 nm (2 nm for TiO2) rms roughness as determined by atomic force microscopy and a full-width at half-maximum (FWHM) of the rocking curve 0002 (200) peak of 5.5/spl degrees/ (3.1/spl degrees/ for TiO2). A Pb[Zr0.52Ti 0.48]O3 layer was deposited and shown to template from the textured Pt electrode, with a maximum [111] Lotgering factor of 87% and a minimum 111 FWHM of 2.4/spl degrees/ at approximately 30 nm of original Ti.
Precise Onboard Orbit Determination for LEO Satellites with Real-Time Orbit and Clock Corrections (2016)

Precise Point Positing (PPP) with real-time orbit and clock correction streams has become an established technique over the last decade for land, air and sea applications. The use of real-time corrections for precise positioning has not extended into orbit yet, although a number of low-Earth orbit (LEO) satellite missions have a demand for precise orbit determination (POD). Future satellites with altimeter and radio-occultation payloads may require real-time POD to enable onboard processing of science data for forecasting or nowcasting of meteorology data, open-loop instrument operations of radar payloads, or quick-look onboard science data generation. Also, precise real-time orbit information may be utilized for constellation maintenance of satellite formations. A POD accuracy of a few decimeters or better with precise GPS real-time corrections has repeatedly been demonstrated in the past. For these studies it was assumed that the corrections are continuously available. This is, however, not guaranteed to be the case in a realistic on-orbit scenario, in which the corrections are disseminated via a network of geostationary (GEO) satellites to the LEO satellite. The data link to the GEO constellation may not be available over the polar regions, thus outdated corrections must be used until up-to-date data is received again. These correction data gaps will have an adverse effect on the POD accuracy, especially since the satellite visibility is typically also reduced as well over the North and South pole. To assess the effect of outdated correction data on onboard POD, a Kalman-filter-based navigation algorithm has been used to process real-world GPS observations of a representative LEO satellite mission together with corrections based on real-time orbit and clock products from Fugro. Data gaps of different length have been simulated, during which the corrections must be extrapolated. The magnitude of orbit and clock extrapolation errors is assessed. Clock extrapolation errors are evaluated depending on the satellite block type and clock model. Real-time on-board POD results for the different scenarios are compared to a precise reference solution.
[Fast segmentation algorithm of high resolution remote sensing image based on multiscale mean shift]. (2011)

Mean Shift algorithm is a robust approach toward feature space analysis and it has been used wildly for natural scene image and medical image segmentation. However, high computational complexity of the algorithm has constrained its application in remote sensing images with massive information. A fast image segmentation algorithm is presented by extending traditional mean shift method to wavelet domain. In order to evaluate the effectiveness of the proposed algorithm, multispectral remote sensing image and synthetic image are utilized. The results show that the proposed algorithm can improve the speed 5-7 times compared to the traditional MS method in the premise of segmentation quality assurance.
Covalent Electron Transfer Chemistry of Graphene with Diazonium Salts (2012)

Graphene is an atomically thin, two-dimensional allotrope of carbon with exceptionally high carrier mobilities, thermal conductivity, and mechanical strength. From a chemist's perspective, graphene can be regarded as a large polycyclic aromatic molecule and as a surface without a bulk contribution. Consequently, chemistries typically performed on organic molecules and surfaces have been used as starting points for the chemical functionalization of graphene. The motivations for chemical modification of graphene include changing its doping level, opening an electronic band gap, charge storage, chemical and biological sensing, making new composite materials, and the scale-up of solution-processable graphene. In this Account, we focus on graphene functionalization via electron transfer chemistries, in particular via reactions with aryl diazonium salts. Because electron transfer chemistries depend on the Fermi energy of graphene and the density of states of the reagents, the resulting reaction rate depends on the number of graphene layers, edge states, defects, atomic structure, and the electrostatic environment. We limit our Account to focus on pristine graphene over graphene oxide, because free electrons in the latter are already bound to oxygen-containing functionalities and the resulting chemistries are dominated by localized reactivity and defects. We describe the reaction mechanism of diazonium functionalization of graphene and show that the reaction conditions determine the relative degrees of chemisorption and physisorption, which allows for controlled modulation of the electronic properties of graphene. Finally we discuss different applications for graphene modified by this chemistry, including as an additive in polymer matrices, as biosensors when coupled with cells and biomolecules, and as catalysts when combined with nanoparticles.
Handbook of Auditory Evoked Responses (1991)

1. Overview of AERs: Past, Present, and Future. 2. Anatomy and Physiology. 3. Effect of Nonpathologic Subject Characteristics. 4. Effect of Stimulus Factors. 5. Effect of Acquisition Factors. 6. Waveform Analysis. 7. Calibration, Standards, and Normative Data. 8. Test Protocols and Procedures. 9. Measurement Problems and Solutions. 10. Basic Audiometry. 11. Peripheral Auditory Assessment. 12. Neurodiagnosis: Eighth Cranial Nerve. 13. Neurodiagnosis: Central Nervous System. 14. Newborn Auditory Screening. 15. Intraoperative Monitoring. 16. Intensive Care Unit Monitoring. 17. Nonauditory Evoked Responses. 18. Adults. 19. Children.
Extraction of apoplastic sap from plant roots by centrifugation (1999)

A centrifugal method for extracting apoplastic sap from roots of lupin ( Lupinus angustifolius ) and pea ( Pisum sativum ) plants, and a method to analyse malic dehydrogenase in the sap using capillary electrophoresis, are described. Osmolality of apoplastic sap was relatively constant at relative centrifugal forces (RCFs) between 600 and 3000 g for lupin, and between 600 and 4000 g for pea. Electropherograms of a marker enzyme (malic dehydrogenase) and other components in apoplastic and symplastic saps revealed that contamination occurred at 7000 g . It is suggested that apoplastic sap expelled from plant roots at RCF between 600 and 3000 g is free from symplastic contamination, and is regarded as being of apoplastic origin. The proposed method was used to measure apoplastic pH changes in the plant roots in response to external pH, ammonium, nitrate and vanadate.
Emerging nondestructive inspection methods for aging aircraft (1994)

This report identifies and describes emerging nondestructive inspection (NDI) methods that can potentially be used to inspect commercial transport and commuter aircraft for structural damage. The nine categories of emerging NDI techniques are: acoustic emission, x-ray computed tomography, backscatter radiation, reverse geometry x-ray, advanced electromagnetics, including magnetooptic imaging and advanced eddy current techniques, coherent optics, advanced ultrasonics, advanced visual, and infrared thermography. The physical principles, generalized performance characteristics, and typical applications associated with each method are described. In addition, aircraft inspection applications are discussed along with the associated technical considerations. Finally, the status of each technique is presented, with a discussion on when it may be available for use in actual aircraft maintenance programs. It should be noted that this is a companion document to DOT/FAA/CT-91/5, Current Nondestructive Inspection Methods for Aging Aircraft.
Design and evaluation of data access strategies in a high performance multimedia-on-demand server (2002)

One of the key components of a multi user multimedia on demand system is the data server. Digitization of traditionally analog data such as video and audio, and the feasibility of obtaining network bandwidths above the gigabit per second range are two important advances that have made possible the realization, in the near future, of interactive distributed multimedia systems. Secondary-to-main memory I/O technology has not kept pace with advances in networking, main memory and CPU processing power. Consequently, the performance of the server has a direct bearing on the overall performance of such a system. We develop a model for the architecture of a server for such a system. Parallelism of data retrieval is achieved by striping the data across multiple disks. The performance of any server ultimately depends on the data access patterns. Two modifications of the basic retrieval algorithm are presented to exploit data access patterns in order to improve system throughput and response time. A complementary information caching optimization is discussed. Finally, we present performance results of these algorithms on the IBM SP1 and Intel Paragon parallel computers.