gebhart/patrepeval huggingface dataset:
A Unified Treatment of Partial Stragglers and Sparse Matrices in Coded Matrix Computation (2021)

The overall execution time of distributed matrix computations is often dominated by slow worker nodes (stragglers) within the clusters. Recently, different coding techniques have been utilized to mitigate the effect of stragglers where worker nodes are assigned the job of processing encoded submatrices of the original matrices. In many machine learning or optimization problems the relevant matrices are often sparse. Several prior coded computation methods operate with dense linear combinations of the original submatrices; this can significantly increase the worker node computation times and consequently the overall job execution time. Moreover, several existing techniques treat the stragglers as failures (erasures) and discard their computations. In this work, we present a coding approach which operates with limited encoding of the original submatrices and utilizes the partial computations done by the slower workers. While our scheme can continue to have the optimal threshold of prior work, it also allows us to trade off the straggler resilience with the worker computation speed for sparse input matrices. Extensive numerical experiments done in AWS (Amazon Web Services) cluster confirm that the proposed approach enhances the speed of the worker computations (and thus the whole process) significantly.
Dataset Evolver: An Interactive Feature Engineering Notebook (2018)

We present DATASET EVOLVER, an interactive Jupyter notebook-based tool to support data scientists perform feature engineering for classification tasks. It provides users with suggestions on new features to construct, based on automated feature engineering algorithms. Users can navigate the given choices in different ways, validate the impact, and selectively accept the suggestions. DATASET EVOLVER is a pluggable feature engineering framework where several exploration strategies could be added. It currently includes meta-learning based exploration and reinforcement learning based exploration. The suggested features are constructed using well-defined mathematical functions and are easily interpretable. Our system provides a mixed-initiative system of a user being assisted by an automated agent to efficiently and effectively solve the complex problem of feature engineering. It reduces the effort of a data scientist from hours to minutes.
Erosion and Redeposition of Graphite by Hydrogen Plasmas (1989)

The results of erosion and redeposition studies of graphite by hydrogen plasma bombardment in the PISCES facility are reviewed. The total erosion yields of several types of graphites have been measured during plasma exposure with ion fluxes of up to 2 × 1018 cm−2·s−1, ion energies of 50 to 200 eV, and sample temperatures of 50 to 950°C. Hydrogen and deuterium plasmas have been used to bombard Poco, ATJ, and pyrolytic graphites, and a “four-directional” carbon-carbon (C-C) composite weave. The erosion rates of all the graphites tested are about equal, suggesting that surface damage by the ion bombardment results in similar erosion yields. The C-C composite weave material showed an increased weight loss during initial exposure, and then equal or lower erosion yields compared to the other graphites. Graphite has a strong ion energy dependence in the maximum chemical erosion yield at a temperature of 500 to 600°C and no energy dependence for the erosion at room temperature. At temperatures above 800°C, the chemical erosion is suppressed and the erosion yield reaches values expected for physical sputtering with thresholds of ∼40 eV for both hydrogen and deuterium. The measured erosion rates demonstrate that chemical sputtering is not significantly suppressed by high-ion fluxes. The net erosion is also reduced by reionization in the plasma and redeposition of hydrocarbons and physically sputtered carbon.
Theory and simulation of viscous damped reflection phase gratings (1999)

Micromachined reflection phase gratings operate via the electrostatic deflection of reflective microbeams. We develop a lumped parameter model for predicting the transient motion of these microbeams, taking into account electrostatic and tensile forces and viscous air damping via squeeze-film theory. We use this model to determine the time required for a deflected microbeam to return to its undeflected state. Our analysis shows that this re-set time is approximately one order of magnitude greater than the activation time.
Ferroelectric nematic phase at and below room temperature (2021)

We report a liquid crystal 1 that shows ferroelectricity at room temperature. 1 directly enters the ferroelectric nematic phase from the isotropic phase upon cooling, without the formation of a conventional nematic phase. The synthesis, microscopic texture observations and dielectric spectroscopy measurement results of 1 are presented. A relative permittivity of over 20000 is observed in the ferroelectric nematic phase. Together with its low melting point the new liquid crystal will accelerate application research and device prototyping in various directions.
Development of PDT/PET Theranostics: Synthesis and Biological Evaluation of an 18F-Radiolabeled Water-Soluble Porphyrin (2015)

Synthesis of the first water-soluble porphyrin radiolabeled with fluorine-18 is described: a new molecular theranostic agent which integrates the therapeutic selectivity of photodynamic therapy (PDT) with the imaging efficacy of positron emission tomography (PET). Generation of the theranostic was carried out through the conjugation of a cationic water-soluble porphyrin bearing an azide functionality to a fluorine-18 radiolabeled prosthetic bearing an alkyne functionality through click conjugation, with excellent yields obtained in both cold and hot synthesis. Biological evaluation of the synthesized structures shows the first example of an (18)F-radiolabeled porphyrin retaining photocytotoxicity following radiolabeling and demonstrable conjugate uptake and potential application as a radiotracer in vivo. The promising results gained from biological evaluation demonstrate the potential of this structure as a clinically relevant theranostic agent, offering exciting possibilities for the simultaneous imaging and photodynamic treatment of tumors.
CAPSULE-BASED SELF-HEALING EPOXY SYSTEMS USING DIELS- ALDER REACTIONS (2013)

We present recent results on the use of Diels-Alder reversible reactions for the design of self-healing polymer systems. Previous work has shown that solutions of maleimide functional monomers can be used to heal cracks of furan functionalized epoxy networks. Two topics will be discussed. First, the results of an investigation regarding the influence of solvent selection and maleimide type as well as concentration on healing efficiency, and second, our progress encapsulating solutions containing maleimide-based healing agents to create capsule-based selfhealing systems that rely on Diels-Alder chemistry. The effects of maleimide healing agent structure, concentration, and solvent type on the effectiveness of solution-based healing agents for a furan-functionalized epoxyamine thermoset were investigated. These factors were found to influence healing behavior by affecting two mechanisms: (1) Diels-Alder bonding across the crack surfaces and (2) mechanical interlocking promoted by solvent-induced swelling. Aliphatic and aromatic maleimides with varying functionality were studied. The solvents evaluated were toluene, dimethyl formamide (DMF), and phenyl acetate. The maleimide healing agent structure and concentration were found to affect the degree of Diels-Alder interfacial bodnding, while solvent selection was found to influence both healing mechanisms. A urea-formaldehyde (UF) encapsulation technique was used to encapsulate phenyl acetate – maleimide solutions. The resulting capsules were found to be thermally stable up to 90°C. It was not possible to encapsulate DMF solutions, and solutions using toluene resulted in low capsule yield. Phenyl acetate – maleimide capsules were incorporated into a furan functional epoxy creating a material system that heals autonomously. Compact tension specimens prepared with 10 wt.% capsules showed 75% strength recovery 24 hours after first fracture at ambient temperature. This compares favorably with the direct injection of healing solution into the crack. The new capsule healing system based on Diels-Alder chemistry also provides the opportunity for repeated healing cycles.
Localization of One-Dimensional Thermoelastic Waves in Layered Structures (1999)

Abstract Including the second sound effect, a transfer matrix formulation based on the generalized dynamical theory of thermoelasticity is developed for longitudinal wave component propagation in a thermoelastic layer. The attenuation and propagation properties of one-dimensional thermoelastic wave in both continuum and layered structures are studied using this formulation and the periodic systems framework. Localization of thermal waves is demonstrated in the time-spacial domain by an FFT-based transient analysis. A perturbation analysis tor identifying leading terms in thermal attenuation is performed, and the role of the thermal elastic coupling term in attenuation is determined. The reflection and transmission coefficients between half-spaces are calculated to evaluate the potential practical use of the approach in laser-based nondestructive testing.
In Situ Performance Analysis of a High Temperature PEM Fuel Cell Stack at Loads (2013)

A high temperature PEM fuel cell stack, consisting of 65 planar single cells, was operated in a commercial power module with pure hydrogen and ambient air. AC impedance tests were conducted on the stack module after it reached a steady operating status. The equivalent circuit diagram with three time constants was derived to simulate the measured impedance data. The impedance measurement and simulation were performed to the stack module at different operation settings of stack temperature and load current in order to validate the derived equivalent circuit diagram. In this way, the kinetic and mass transfer processes occurring inside the stack were mechanistically discriminated and identified.
Prenatal exposure to polybrominated diphenylether 99 enhances the function of the glutamate–nitric oxide–cGMP pathway in brain in vivo and in cultured neurons (2007)

Polybrominated diphenylethers (PBDEs) are widely used as flame retardants. Significant amounts of PBDEs are present in the milk of lactating women. The possible neurotoxic effects of PBDEs are not well known. Perinatal exposure to PBDEs affects both motor and cognitive functions by mechanisms that remain unclear. Some types of learning depend on N-methyl-D-aspartate receptor activation, which increases intracellular calcium that binds to calmodulin and activates nitric oxide synthase, increasing nitric oxide formation that activates guanylate cyclase, increasing cGMP formation. Part of this cGMP is released to the extracellular fluid. We studied whether prenatal exposure of rats to PBDE99 alters the function of this glutamate-nitric oxide-cGMP pathway in rat brain in vivo. At 10 weeks of age, rats treated with PBDE99 showed increased function of the glutamate-nitric oxide-cGMP pathway in brain in vivo, as assessed by microdialysis in freely moving rats. The increased function of the pathway was reproduced in primary cultures of cerebellar neurons prepared from rats prenatally exposed to PBDE99 as well as in neurons cultured from normal rats and treated in vitro with PBDE99. Increased calmodulin content and activation of soluble guanylate cyclase by nitric oxide contributed to the increased function of the pathway.
Soft Magnetic Properties of FeSi/FeSiO Multilayered Films Prepared by PRS Method. (1999)

The soft magnetic properties of Fe(Si)/Fe(Si)O multilayered films were investigated. The films were prepared by the pulse-reactive sputtering (PRS) method, which enables multilayered films to be deposited as fast as single films. The soft magnetic properties of the as-prepared films were improved by adding Si. The films show Bs of 1.82-1.87 T and μi' of around 1000 at 300 MHz. A film with Bs of 1.82 T shows μi' of around 1000 at 350 MHz, even after patterning into 18.5 μm-wide stripes.
Water-soluble hemicelluloses for high humidity applications – enzymatic modification of xyloglucan for mechanical and oxygen barrier properties (2013)

Bio-based polymers are of increasing interest in packaging applications as alternatives to petroleum-based polymers. Xyloglucan (XG) derived from tamarind seed waste was recently explored as a high performance biopolymer for packaging applications. Xyloglucan films have high strength, stiffness and oxygen barrier performance, but suffer from limitations in properties under high humidity conditions. This aspect is addressed in the present work using XG modification by enzymatic removal of side chain galactose residues. The modified XG was characterized using carbohydrate analysis and MALDI-TOF MS analysis for sugar and oligosaccharide compositions respectively. The consequence of galactose removal for XG chain packing was theoretically predicted using a group contribution method and the estimation of Hansen's solubility parameters. The properties of films made from modified XG in terms of tensile, oxygen transmission rate, and thermo-mechanical behaviour were measured and related to the structure of modified XGs. Modified XG films preserved the Young's modulus at high humidity at a level of 4.3 GPa at 92% relative humidity. Moreover, the oxygen permeability of modified XG samples was very low and was about 1.5 cc μm [m2 day]−1 kPa−1 at 80% relative humidity, more than 80% lower than that for native XG. The main reason is that modified XG absorbs less moisture, due to a decreased solubility. Decreased free volume may also contribute, as galactose residues are removed and XG branches become shorter.
Electric Characteristics of Si3N4 Films Formed by Directly Radical Nitridation on Si(110) and Si(100) Surfaces (2007)

High quality Si3N4 film was formed by the nitridation of Si(110) surface using radical NH. It was found that the gate leakage current through the Si3N4 film is three orders of magnitude smaller than that through the conventional SiO2 film, and the interface states density at midgap for Si3N4/Si interface is less than 5×1010 eV-1 cm-2. High-resolution soft-X-ray-excited Si 2 p spectra were measured for the Si3N4 films formed on Si(100), Si(110) and Si(111). It was found that the crystal orientation of the Si substrate affects the amount of intermediate nitridation states of Si at the Si3N4/Si interface.
Feeding Systems and Host Breeds Influence Ruminal Fermentation, Methane Production, Microbial Diversity and Metagenomic Gene Abundance (2021)

Our previous research revealed the advantages of separate feeding (SF) systems compared to total mixed ration (TMR) in terms of ruminal methane (CH<sub>4</sub>) production. The purpose of this experiment was to confirm the advantage of SF as a nutritional strategy for CH<sub>4</sub> mitigation, and to determine the effects of different feeding systems (TMR and SF) on the rumen microbiome and associated metagenome of two different breeds and on CH<sub>4</sub> emissions. We randomly allocated four Holstein (305 ± 29 kg) and four Hanwoo steers (292 ± 24 kg) to two groups; the steers were fed a commercial concentrate with tall fescue (75:25) as TMR or SF, in a crossover design (two successive 22-day periods). Neither feeding systems nor cattle breeds had an effect on the total tract digestibility of nutrients. The TMR feeding system and Hanwoo steers generated significantly more CH<sub>4</sub> (<i>P</i> < 0.05) and had a higher yield [g/d and g/kg dry matter intake (DMI)] compared to the SF system and Holstein steers. A larger rumen acetate:propionate ratio was observed for the TMR than the SF diet (<i>P</i> < 0.05), and for Hanwoo than Holstein steers (<i>P</i> < 0.001), clearly reflecting a shift in the ruminal H<sub>2</sub> sink toward CH<sub>4</sub> production. The linear discriminant analysis (LDA) effect size (LEfSe) revealed a greater abundance (α < 0.05 and LDA > 2.0) of operational taxonomic units (OTUs) related to methanogenesis for Hanwoo steers compared to Holstein steers. Kendall's correlation analysis revealed wide variation of microbial co-occurrence patterns between feeding systems, indicating differential H<sub>2</sub> thermodynamics in the rumen. A metagenome analysis of rumen microbes revealed the presence of 430 differentially expressed genes, among which 17 and 27 genes exhibited positive and negative associations with CH<sub>4</sub> production, respectively (<i>P</i> < 0.001). A strong interaction between feeding system and breed was observed for microbial and metagenomic abundance. Overall, these results suggest that the TMR feeding system produces more CH<sub>4</sub>, and that Hanwoo cattle are higher CH<sub>4</sub> emitters than SF diet and Holstein cattle, respectively. Interestingly, host-associated microbial interactions differed within each breed depending on the feeding system, which indicated that breed-specific feeding systems should be taken into account for farm management.
Complexation of phthalate oxygens in poly(ethylene phthalate) with silver ions and its effect on the formation of silver nanoparticles (2004)

Abstract The interaction of a phthalate group in poly(ethylene phthalate) (PEP) with silver ion has been elaborated in detail to understand the reduction behavior of silver ions to silver nanoparticles. Previously, the polymer electrolytes consisting of silver ions dissolved in PEP have shown highly stable separation performance for propylene/propane mixtures primarily due to the retardation of the reduction reaction of silver ions to silver nanoparticles, which is possible by means of the chelating bonds between phthalate groups and silver ions. Thus, in this study, the interaction was systematically investigated by both the theoretical ab initio calculation and the experimental Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy. The results show that the interaction of silver ion with phthalate group in PEP is approximately two times stronger than that with other functional groups such as amide, ketone, and ester in various polymers, in which the latter ones show the rapid reduction reaction and consequently lose their olefin carrier activity with time. Therefore, it is concluded that the reduction reaction of silver ions to silver nanoparticles is retarded remarkably in PEP/silver salts systems primarily because of the strong interaction between the phthalate group in PEP and silver ion, and consequently the formation of silver nanoparticles would be effectively prohibited, as confirmed by transmission electron microscopy and ultraviolet–visible spectroscopy. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3344–3350, 2004
Mechanisms of Deformation and Failure in Carbon‐Matrix Composites Subject to Tensile and Shear Loading (1995)

The operative damage mechanisms in a series of C‐matrix composites loaded in tension and shear have been investigated. The composites contained either C fibers or Nicalon fibers, both with and without a carbon coating. The matrix consisted primarily of ex‐phenolic carbon with a final carbon layer introduced by chemical vapor infiltration. Some composites have a high fiber/matrix sliding stress. In these composites, failure is characterized by localized fiber pullout. Other composites have a low. Failure of these materials is characterized by stochastic fiber failure with a diffuse fracture surface. The operative damage mechanisms have been identified and used in conjunction with available models to rationalize composite performance in terms of constituent properties (fiber, matrix, interface). The properties emphasized include the inelastic strain, as well as the ultimate tensile and shear strengths.
High Temperature High Performance Liquid Chromatography of Substituted Anilines using a C18 Hybrid Stationary Phase (2006)

Abstract Separation of twelve substituted anilines in less than ten minutes is reported. A C18 hybrid stationary phase and a mobile phase consisting of pure water was used for separation. To separate the analytes a temperature program between 160°C and 200°C with 5°C/min was used. Under isothermal conditions van't Hoff plots were constructed between 150°C and 200°C. All the plots were straight lines indicating only one type of interaction between the analytes and the stationary phase. The compounds were detected using either UV or simultaneous UV and FID detection.
Adaptive Blind Channel Equalization (2012)

Shafayat Abrar1, Azzedine Zerguine2 and Asoke Kumar Nandi3 1Department of Electrical Engineering, COMSATS Institute of Information Technology, Islamabad 44000 2Department of Electrical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 3Department of Electrical Engineering and Electronics, The University of Liverpool, Liverpool L69 3BX 1Pakistan 2Saudi Arabia 3United Kingdom
Ultra-compact switchable SLO/OCT handheld probe design (2015)

Handheld scanning laser ophthalmoscopy (SLO) and optical coherence tomography (OCT) systems facilitate imaging of young children and subjects that have difficulty fixating. More compact and lightweight probes allow for better portability and increased comfort for the operator of the handheld probe. We describe a very compact, novel SLO and OCT handheld probe design. A single 2D microelectromechanical systems (MEMS) scanner and a custom optical design using a converging beam prior to the scanner permitted significant reduction in the system size. Our design utilized a combination of commercial and custom optics that were optimized in Zemax to achieve near diffraction-limited resolution of 8 μm over a 7° field of view. The handheld probe has a form factor of 7 x 6 x 2.5 cm and a weight of only 94 g, which is over an order of magnitude lighter than prior SLO-OCT handheld probes. Images were acquired from a normal subject with an incident power on the eye under the ANSI limit. With this device, which is the world’s lightest and smallest SLO-OCT system, we were able to visualize parafoveal cone photoreceptors and nerve fiber bundles without the use of adaptive optics.
Analytical Calculation of the Residual ZVS Losses of TCM-Operated Single-Phase PFC Rectifiers (2021)

Triangular-current-mode (TCM) modulation guarantees zero-voltage-switching across the mains cycle in AC-DC power converters, eliminating hard-switching with a minor ≈ 30% penalty in conduction losses over the conventional continuous current mode (CCM) modulation scheme. TCM-operated converters, however, include a wide variation in both switching frequency and switched current across the mains cycle, complicating an analytical description of the key operating parameters to date. In this work, we derive an analytical description for the semiconductor bridge-leg losses in a TCM AC-DC converter, including the rms current and/or conduction losses, switching frequency, and switching losses. For SiC mosfets, we introduce a new loss model for switching losses under zero-voltage-switching, which we call “residual ZVS losses”. These losses include the constant C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">oss</sub> losses found in previous literature but must also add, we find, turn-off losses that occur at high switched currents. The existence and modeling of these turn-off losses, which are due to currents flowing through the Miller capacitance and raise the inner gate source voltage to the threshold level and accordingly limit the voltage slew rate, are validated on the IMZA65R027M1H 650V SiC mosfet. The complete loss model - and the promise of TCM for high power density and high efficiency - is validated on a 2.2 kW hardware bridge-leg demonstrator, which achieves a peak 99.6% semiconductor efficiency at full load. The proposed, fully-analytical model predicts bridge-leg losses with only 12% deviation at the nominal load, accurately including residual ZVS losses across load, modulation index, and external gate resistance.