gebhart/patrepeval huggingface dataset:
Advancement on Lead-Free Organic-Inorganic Halide Perovskite Solar Cells: A Review (2018)

Remarkable attention has been committed to the recently discovered cost effective and solution processable lead-free organic-inorganic halide perovskite solar cells. Recent studies have reported that, within five years, the reported efficiency has reached 9.0%, which makes them an extremely promising and fast developing candidate to compete with conventional lead-based perovskite solar cells. The major challenge associated with the conventional perovskite solar cells is the toxic nature of lead (Pb) used in the active layer of perovskite material. If lead continues to be used in fabricating solar cells, negative health impacts will result in the environment due to the toxicity of lead. Alternatively, lead free perovskite solar cells could give a safe way by substituting low-cost, abundant and non toxic material. This review focuses on formability of lead-free organic-inorganic halide perovskite, alternative metal cations candidates to replace lead (Pb), and possible substitutions of organic cations, as well as halide anions in the lead-free organic-inorganic halide perovskite architecture. Furthermore, the review gives highlights on the impact of organic cations, metal cations and inorganic anions on stability and the overall performance of lead free perovskite solar cells.
Improved Tag-based Indoor Localization of UAVs Using Extended Kalman Filter (2019)

Improved Tag-based Indoor Localization of UAVs Using Extended Kalman Filter Navid Kayhani, Adam Heins, Wenda Zhao, Mohammad Nahangi, Brenda McCabe and Angela Schoellig Pages 624-631 (2019 Proceedings of the 36th ISARC, Banff, Canada, ISBN 978-952-69524-0-6, ISSN 2413-5844) Abstract: Indoor localization and navigation of unmanned aerial vehicles (UAVs) is a critical function for autonomous flight and automated visual inspection of construction elements in continuously changing construction environments. The key challenge for indoor localization and navigation is that the global positioning system (GPS) signal is not sufficiently reliable for state estimation. Having used the AprilTag markers for indoor localization, we showed a proof-of-concept that a camera-equipped UAV can be localized in a GPS-denied environment; however, the accuracy of the localization was inadequate in some situations. This study presents the implementation and performance assessment of an Extended Kalman Filter (EKF) for improving the estimation process of a previously developed indoor localization framework using AprilTag markers. An experimental set up is used to assess the performance of the updated estimation process in comparison to the previous state estimation method and the ground truth data. Results show that the state estimation and indoor localization are improved substantially using the EKF. To have a more robust estimation, we extract and fuse data from multiple tags. The framework can now be tested in real-world environments given that our continuous localization is sufficiently robust and reliable. Keywords: Unmanned aerial vehicles (UAV); Building Information model (BIM); Indoor navigation; Autonomous flight; Visual inspection; Construction automation; Extended Kalman filter (EKF) DOI: https://doi.org/10.22260/ISARC2019/0083 Download fulltext Download BibTex Download Endnote (RIS) TeX Import to Mendeley
An inhomogeneous reference catalogue of identified intervening heavy element systems in spectra of QSOs (1991)

Identifications of heavy element line systems, observed in spectra of quasi-stellar objects between 1965 and 1989 inclusive, are collected and tabulated with references. Each system is assigned a quality grade based on the apparent reliability of the data. The highest quality systems are used to characterize the absorbers as a sample. We confirm a decrease in C IV line strength with redshift (z), and the corresponding decrease in line density per unit z with z. The weakest C IV systems, at high z, are accompanied by relatively stronger Si IV lines, compared to the relative line strengths at low z. The space density of systems with strong lines of first ions is nearly independent of z below z = 3, though it drops at z > 3. Preliminary tests for quasar lensing by intervening systems and for clustering of absorbers on large scales are presented.
The Computation of Saturation Vapor Pressure (1974)

The physical rationale of the concept of saturation vapor pressure is briefly discussed. Several procedures for the computation of saturation vapor pressure and its derivatives with respect to temperature are examined and evaluated with reference to accuracy relative to currently accepted standards and with reference to computational speed. It is demonstrated that it is possible to devise a set of 6th order polynomial approximations with better than satisfactory accuracy and, further, that these formulas require considerably less computation time than other currently used procedures. Polynomials are derived for various temperature ranges for both ice and water references.
Corrosion properties of stainless steel coatings made by different methods of thermal spraying (1994)

The corrosion protection ability of thermally sprayed stainless steel coatings in aggressive environments is considerably limited as compared to bulk materials of the same composition. The two main reasons for the decrease in corrosion resistance are the porosity in the coatings and the oxidation of elements, particularly chromium, during spraying process. The corrosion resistance and structure of stainless steel coatings, ANVAL 254 SMO, made by different methods of thermal spraying were evaluated in this work. The coatings were produced by atmospheric plasma spraying (APS), atmospheric plasma spraying using gas shielding around the plasma (APS/S), low pressure plasma spraying (LPPS), detonation gun spraying (DGS) and high velocity oxyfuel spraying (HVOF). Electrochemical methods were used for determining the corrosion protection ability of coatings in 3.5% NaCl-solution and in sulfur acid solution (pH 3 and 1). The structure and composition of coatings were studied by optical microscopy and scanning electron microscopy/energy dispersive analysator (SEM/EDS). The porosity of the coatings was determined by water impregnation method, optical microscopy and mercury porosimeter. The results showed that the best coating quality can be achieved by LPPS- and HVOF-coatings. Oxidation and porosity restrict the use of APS-coatings in corrosive environments. The oxidation can be avoided by usingmore » argon gas shield around the plasma flame during spraying. Due to porosity all studied coatings suffered crevice corrosion in chloride solution. Despite high Mo-alloying the best coatings reached only the corrosion resistance of AISI 316.« less
Bioprinting-Based High-Throughput Fabrication of Three-Dimensional MCF-7 Human Breast Cancer Cellular Spheroids (2015)

Cellular spheroids serving as three-dimensional (3D) in vitro tissue models have attracted increasing interest for pathological study and drug-screening applications. Various methods, including microwells in particular, have been developed for engineering cellular spheroids. However, these methods usually suffer from either destructive molding operations or cell loss and non-uniform cell distribution among the wells due to two-step molding and cell seeding. We have developed a facile method that utilizes cell-embedded hydrogel arrays as templates for concave well fabrication and in situ MCF-7 cellular spheroid formation on a chip. A custom-built bioprinting system was applied for the fabrication of sacrificial gelatin arrays and sequentially concave wells in a high-throughput, flexible, and controlled manner. The ability to achieve in situ cell seeding for cellular spheroid construction was demonstrated with the advantage of uniform cell seeding and the potential for programmed fabrication of tissue models on chips. The developed method holds great potential for applications in tissue engineering, regenerative medicine, and drug screening.
Protein Phosphatase 2A and DNA-dependent Protein Kinase Are Involved in Mediating Rapamycin-induced Akt Phosphorylation (2013)

A previously unknown mechanism underlying rapamycin-induced Akt phosphorylation and a novel strategy to enhance mTOR-targeted cancer therapy may be suggested. Inhibition of mammalian target of rapamycin complex 1 (mTORC1), for example with rapamycin, increases Akt phosphorylation while inhibiting mTORC1 signaling. However, the underlying mechanisms have not been fully elucidated. The current study has uncovered a previously unknown mechanism underlying rapamycin-induced Akt phosphorylation involving protein phosphatase 2A (PP2A)-dependent DNA protein kinase (DNA-PK) activation. In several cancer cell lines, inhibition of PP2A with okadaic acid, fostriecin, small T antigen, or PP2A knockdown abrogated rapamycin-induced Akt phosphorylation, and rapamycin increased PP2A activity. Chemical inhibition of DNA-PK, knockdown or deficiency of DNA-PK catalytic subunit (DNA-PKcs), or knock-out of the DNA-PK component Ku86 inhibited rapamycin-induced Akt phosphorylation. Exposure of cancer cells to rapamycin increased DNA-PK activity, and gene silencing-mediated PP2A inhibition attenuated rapamycin-induced DNA-PK activity. Collectively these results suggest that rapamycin induces PP2A-dependent and DNA-PK-mediated Akt phosphorylation. Accordingly, simultaneous inhibition of mTOR and DNA-PK did not stimulate Akt activity and synergistically inhibited the growth of cancer cells both in vitro and in vivo. Thus, our findings also suggest a novel strategy to enhance mTOR-targeted cancer therapy by co-targeting DNA-PK.
A new face down bonding technique using a low melting point metal (1990)

A description is given of a face-down bonding technique, the low-melting-point metal connection (LMC) technique, for use in manufacturing liquid-crystal display (LCD) panels. By using a low melting point metal, such as an indium alloy, it is possible to connect the integrated circuit (IC) electrodes and bonding pads on a glass substrate at a temperature lower than 150 degrees C. First, using the dipping method, low-melting-point metal bumps were formed on the IC bonding pads with gold bumps. Shallow-bowl-shaped bumps, 10-20 mu m high, were the result. Next, the IC and the glass substrate were connected at a pressure of 30 gf/bump or less and a temperature of 150 degrees C or less. Two kinds of reliability tests were performed on this sample. One was a thermal shock test (TST): a repetition of -40 and 100 degrees C for 30 min each, for 300 cycles. The other was a high-temperature and high-humidity test: 70 degrees C, 90% relative humidity (RH) for 500 h. In both tests, stable results were obtained. Finally, dot matrix LCD panels, with 640*400 dots, were assembled with 20 driver IC chips. The panels displayed test patterns perfectly. The LMC technique makes it easy to test and repair the IC bonds. The results of the trial manufacturing and testing show that the LMC technique can be readily applied in manufacturing LCD panels and many other kinds of electronic equipment.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Uncalibrated Near-Light Photometric Stereo (2015)

In this work we solve the uncalibrated photometric stereo problem with lights placed near the scene. We investigate different image formation models and find the one that best fits our observations. Although the devised model is more complex than its far-light counterpart, we show that under a global linear ambiguity the reconstruction is possible up to a rotation and scaling, which can be easily fixed. We also propose a solution for reconstructing the normal map, the albedo, the light positions and the light intensities of a scene given only a sequence of near-light images. This is done in an alternating minimization framework which first estimates both the normals and the albedo, and then the light positions and intensities. We validate our method on real world experiments and show that a near-light model leads to a significant improvement in the surface reconstruction compared to the classic distant illumination case.
Digital Augmentation of RF Component Performance in Software-Defined Radio (2009)

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper presents two tools for feedforward correction in transmitter chains in software-defined radio. The methods presume that the radio configuration already has a gate array and a mixer juxtaposed with one another. Programming is added in the gate array to affect preconditioning of the signals presented to in-phase and quadrature channels of a hybrid mixer so as to correct and enhance the analog RF performance of the mixer. The first of the methods comprises a realization with off-the-shelf components of feedback of the RF output of the mixer. Spectrum analysis in the gate array allows separation and cancellation of the unwanted difference-frequency sideband in the mixer's output. The second tool is a feedforward correction of imperfect performance of a hybrid mixer. The correction parameters are determined through sideband reduction via the feedback scheme in the first method. It is shown that the correction scheme performs well even for very large deviations from the ideal in the mixer parameters. As a consequence, the scheme may be used to extend the operating band of the gate-array/mixer combination to extreme bandwidths—approaching 200%. </para>
Quantity and Potential Biological Activity of Caffeic Acid in Sweet Potato [<i>Ipomoea</i> <i>batatas</i> (L.) Lam.] Storage Root Periderm (2003)

The caffeic acid content of storage root periderm and cortex tissues of genetically diverse sweet potato [Ipomoea batatas (L.) Lam.] cultivars and breeding clones was quantified by high-performance liquid chromatography. Periderm caffeic acid content of the clones ranged from 0.008 to 7.97 mg/g dry weight, whereas the highest cortex content was 0.047 mg/g. Clones varied greatly in periderm caffeic acid content in all experiments, but there were also differences between experiments in content averaged for all clones. This indicates that periderm caffeic acid content is subject to genetic and environmental influences. Caffeic acid inhibited the growth of four sweet potato pathogenic fungi and germination of proso millet seeds in bioassays. Inhibitory activity in the bioassays suggests that high periderm caffeic acid levels contribute to the storage root defense chemistry of some sweet potato genotypes.
The architecture of a heterogeneous distributed database management system (1992)

This paper describes the architecture of a heterogeneous distributed database management system called the Distributed Access View Integrated Database (DAVID). The DAVID system allows uniform access to distributed data stored in different DBMSs that support various data models. The system presents the users with a unified cluster data model and with a uniform high level query language (GSQL). Database heterogeneity issues such as external-to-conceptual view translation, view integration, query processing and the definition of a uniform data access language are presented in the context of the DAVID development.
The Cellulosome: A Natural Bacterial Strategy to Combat Biomass Recalcitrance (2008)

This chapter contains sections titled: Introduction The cellulosome concept Cellulosomal carbohydrate-active enzymes The cellulosome–cellulose interaction Cell-surface disposition of cellulosomes Cellulosome assault on recalcitrant cellulose substrates Degradation of cellulose by the C. thermocellum cellulosome The cellulosome rationale Acknowledgments References
Analysis and modeling of a single-phase brushless DC motor drive system (1989)

A single-phase brushless DC motor drive system with a bifilar stator winding and asymmetrical stator pole faces is investigated. The form of the permanent-magnet component of the stator winding flux linkage is analyzed considering the asymmetry of the stator pole faces. Equations describing the electromechanical dynamics of the motor are then derived along with an expression for the electromagnetic torque. These equations are expressed in state-model form, and a mathematical model of the inverter is developed for use in a computer simulations. The computer simulation is used to demonstrate steady-state and dynamic operation of the motor. Comparison of simulation results with measurements of an actual motor-inverter system indicate that the computer model is reasonably accurate.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Health Recommender Systems: A State-of-the-Art Review (2019)

The use of information technologies in the health domain started decades ago, nevertheless there are still many issues that need to be addressed. Health Recommender Systems (HRSs) constitute a promising alternative when it comes to providing tools to assist doctors in the diagnosis of diseases, as well as to help patients with recommendations in regards of how to keep their wellness. This work provides insights about methods and techniques used in the design and development of HRSs, focusing on the areas or types of the recommendations these systems provide and the data representations they employ to build their knowledge base. For this effect, a number of articles published between January 2006 and August 2018, from five different scientific databases, were retrieved. After an examination and selection of publications, 249 articles were categorized by means of a classification framework which was built upon related works and the content of the studies analyzed. Furthermore, the results of the classification are presented and major findings are outlined and discussed.
Monte Carlo Simulation of Nanoparticle Encapsulation in Flames (1999)

Gas-phase combustion (flame) synthesis has been an essential industrial process for producing large quantities of powder materials such as carbon black, titanium dioxide, and silicon dioxide. Flames typically produce simple oxides, with carbon black being the noted exception because the oxides of carbon are gaseous and are easily separated from the particulate matter that is formed during fuel pyrolysis. Furthermore, the powders produced in flames are usually agglomerated, nanometer-sized particles (nanoparticles). This composition and morphology is acceptable for many applications. However, the present interest in nanoparticles for advanced materials application has led to efforts to employ flames for the synthesis of unagglomerated nanoparticles (2 to 100 nm) of metals and non-oxide ceramics. Sodium-halide chemistry has proven to be viable for producing metals and non-oxide ceramics in flames. Materials that have been produced to date include Si (Calcote and Felder, 1993), TiN, TiB2, TiC, TiSi2, SiC, B4C (Glassman et al, 1993) Al, W, Ti, TiB2, AlN, and W-Ti and Al-AlN composites (DuFaux and Axelbaum, 1995, Axelbaum et al 1996,1997). Many more materials are possible. The main challenge that faces application of flame synthesis for advanced materials is overcoming formation of agglomerates in flames (Brezinsky, 1997). The high temperatures and high number densities in the flame environment favor the formation of agglomerates. Agglomerates must be avoided for many reasons. For example, when nanopowders are consolidated, agglomerates have a deleterious effect on compaction density, leading to voids in the final part. Efforts to avoid agglomeration in flames without substantially reducing particle number density and, consequently, production rate, have had limited success. Another critical challenge that faces all synthesis routes for nanopowders is ensuring that the powders are high purity and that the process is scaleable. Though the containerless, high temperature environment of a flame is excellent for producing high-purity simple compounds, ultrafine metals and non-oxide ceramic powders are inherently reactive in the presence of oxygen and/or moisture. Thus, the handling of these powders after synthesis poses a challenging problem. Impurities acquired during handling of nanoparticles have plagued the advancement of nanostructured materials technology.
Ultra‐stable phosphoglucose isomerase through immobilization of cellulose‐binding module‐tagged thermophilic enzyme on low‐cost high‐capacity cellulosic adsorbent (2011)

One-step enzyme purification and immobilization were developed based on simple adsorption of a family 3 cellulose-binding module (CBM)-tagged protein on the external surface of high-capacity regenerated amorphous cellulose (RAC). An open reading frame (ORF) Cthe0217 encoding a putative phosphoglucose isomerase (PGI, EC 5.3.1.9) from a thermophilic bacterium Clostridium thermocellum was cloned and the recombinant proteins with or without CBM were over-expressed in Escherichia coli. The rate constant (kcat ) and Michaelis-Menten constant (Km ) of CBM-free PGI at 60°C were 2,765 s(-1) and 2.89 mM, respectively. PGI was stable at a high protein concentration of 0.1 g/L but deactivated rapidly at low concentrations. Immobilized CBM (iCBM)-PGI on RAC was extremely stable at ∼60°C, nearly independent of its mass concentration in bulk solution, because its local concentration on the solid support was constant. iCBM-PGI at a low concentration of 0.001 g/L had a half-life time of 190 h, approximately 80-fold of that of free PGI. Total turn-over number of iCBM-PGI was as high as 1.1×10(9) mole of product per mole of enzyme at 60°C. These results suggest that a combination of low-cost enzyme immobilization and thermoenzyme led to an ultra-stable enzyme building block suitable for cell-free synthetic pathway biotransformation that can implement complicated biochemical reactions in vitro.
Reactive ion etching of quartz and glasses for microfabrication (1999)

The reactive ion etching (RIE) of quartz and of silica-based glasses has been examined in CF<SUB>4</SUB>/CHF<SUB>3</SUB> plasmas. The etch rate was shown to reduce strongly with an increasing percentage of non-volatile elements in the glass. The etching of the quartz and the Suprasil 2 and Herasil 2 glasses was consistent with a process of ion-enhanced chemical reaction as identified by Steinbruchel. For these substrates, the etch rate was directly dependent on the square root of bias voltage in the RIE and increased with the ratio of CF<SUB>4</SUB>:CHF<SUB>3</SUB> in the gas mixture. The comparatively low etch rates of the LE, soda-lime and NA glasses were equivalent in both the CHF<SUB>3</SUB>/CF<SUB>4</SUB> and Ar plasmas, indicating a process of sputter etching. The BK7 glass has shown intermediate characteristics with a higher etch rate in CF<SUB>4</SUB>/CHF<SUB>3</SUB> than in Ar plasma, indicating ion enhanced chemical etching but with little dependence on the CF<SUB>4</SUB>:CHF<SUB>3</SUB> gas ratio. These results have been applied in the fabrication of grating patterns.
Emergency Landing Planning for Damaged Aircraft (2008)

Considerable progress has been made over the last 15 years on building adaptive control systems to assist pilots in flying damaged aircraft. Once a pilot has regained control of a damaged aircraft, the next problem is to determine the best site for an emergency landing. In general, the decision depends on many factors including the actual control envelope of the aircraft, distance to the site, weather en route, characteristics of the approach path, characteristics of the runway or landing site, and emergency facilities at the site. All of these influence the risk to the aircraft, to the passengers and crew, and to people and property on the ground. We describe an ongoing project to build and demonstrate an emergency landing planner that takes these various factors into consideration and proposes possible routes and landing sites to the pilot, ordering them according to estimated risk. We give an overview of the system architecture and input data, describe our preliminary modeling of risk, and describe how we search the space of landing sites and routes.