gebhart/patrepeval huggingface dataset:
Reducing spacecraft state uncertainty through indirect trajectory optimization (2005)

This chapter presents a method to transfer a spacecraft with continuous thrust while minimizing a combination of fuel consumption and the uncertainty of the spacecraft state in a frame other than the one in which the spacecraft equations of motion and covariance are expressed.The technique allows one to minimize the uncertainty in the spacecraft semimajor axis, flight path angle, range, or any other function of the spacecraft state without developing the equations of motion for the spacecraft or covariance in a non-Cartesian frame.An example problem demonstrates that this technique yields the same optimal trajectory as formulating the entire problem in the state space of the covariance term that is minimized.Another example demonstrates that the covariance associated with the semimajor axis at the end of a LEO to near GEO transfer can be reduced significantly with only a slight increase in fuel consumption. Superscripts* nominal perturbed backward + perturbed forward & denotes a partial derivative mapped to a common time
PoWER-BERT: Accelerating BERT Inference via Progressive Word-vector Elimination (2020)

We develop a novel method, called PoWER-BERT, for improving the inference time of the popular BERT model, while maintaining the accuracy. It works by: a) exploiting redundancy pertaining to word-vectors (intermediate encoder outputs) and eliminating the redundant vectors. b) determining which word-vectors to eliminate by developing a strategy for measuring their significance, based on the self-attention mechanism. c) learning how many word-vectors to eliminate by augmenting the BERT model and the loss function. Experiments on the standard GLUE benchmark shows that PoWER-BERT achieves up to 4.5x reduction in inference time over BERT with <1% loss in accuracy. We show that PoWER-BERT offers significantly better trade-off between accuracy and inference time compared to prior methods. We demonstrate that our method attains up to 6.8x reduction in inference time with <1% loss in accuracy when applied over ALBERT, a highly compressed version of BERT. The code for PoWER-BERT is publicly available at https://github.com/IBM/PoWER-BERT.
Accuracy of Analytical Treatments for Resonance Absorption in Doppler Resonance Regions (1970)

Resonance shielding factors based on the assumption of constant collision density have been compared with those obtained by solving rigorously the slowing down equation. The results obtained by calculating numerically the flux for this assumption have been thoroughly examined for several compositions and temperatures. This detailed investigation has been based on consideration of the interaction effects between neighboring resonances in both the same and different nuclear species. The results obtained have permitted determination of the limits of accuracy obtained with conventional analytical methods. The accuracy of two typical methods of approximation based on the above basic assumption has also been investigated for important Doppler resonance regions in large fast reactor. The study has covered the resonance regions below 21.5 keV for 238U, and below lOkeV for 235U and 239Pu. It has been found that the results obtained numerically from the assumption of constant collision density are fairly good at higher energies, but the errors become large with decreasing neutron energy and the increasing concentration of fuel. Furthermore the shielding factor and the temperature coefficient of 239Pu are affected considerably by superposition of the resonances of 238U, and the errors are thereby accentuated by a factor of more than two. And the errors resulting from the analytical methods have been found larger than those incurred by the assumption of constant collision density.
Radiation power of NbN-based flux-flow oscillators for THz-band integrated SIS receivers (2003)

To develop an efficient local oscillator (LO) integrated with a SIS mixer operating above the gap frequency of Nb, we have investigated the radiation power P of NbN-based flux-flow-type Josephson oscillators (FFO's). The designed and fabricated chip incorporates FFO's, SIS power detectors (DET's), and their coupling circuits. Both FFO's and DET's consist of epitaxial NbN/AlN/NbN junctions with high critical current density J/sub C/ (15<J/sub C/<78 kA/cm/sup 2/). The most part of the coupling circuit consists of NbN/SiO/sub 2//Al microstrip lines whose rf-loss is approximately 3 dB. It has been found P>200 nW, enough for the optimum pumping of a SIS mixer with rf-resistance of 50 /spl Omega/, is coupled to DET's for 0.5-0.9 THz. The coupling bandwidth is larger than 20% of its central frequency. In the band, the radiation frequency is tuned by the control current through the FFO of 10-100 mA. The maximum coupling frequency of the present experiment is quantitatively agreed with the theoretical one. The peak power of 1.3 /spl mu/W is detected at 0.76 THz. The dissipated power in a FFO is smaller than 500 /spl mu/W, which is 10/sup -4/ times less than that of semiconductor sources. These results indicate the feasibility of NbN-based FFO's for a practical on-chip LO.
Characterization of the AIN–W Interface in a Cofired Multilayer AIN Substrate (1989)

The AIN–W Interfaces in a cofired multilayer AIN substrate were observed using an optical microscope, scanning electron microscope (SEM) and transmission electron microscope (TEM). Optical and SEM observations showed an intricate intricatelocking AIN‐W grain structure at the interface. After the W pad was removed from the substrate with a NaOH etchant, the surface morphology of the W metal at the interface side was found to be very rough, with a small‐grain microstructure compared with that at the free surface side. Electron microprobe analyses using SEM revealed that there was no diffusion of either W or Al at the interface at the order of a few micrometer's resolution. Bright‐field images, dark‐field images and selected area electron diffraction (SAD) patterns using TEM indicated there was no secondary phase between AIN and W. However, scanning transmission electron microscopy using an energy dispersive X‐ray detector revealed that there was a 200‐nm thick W diffusion layer from the interface into the AIN ceramics. It was concluded that the high adhesion strength between the W conductor and the AIN substrate (>20 MPa) was not due to any secondary phase but to mechanical interlocking of AIN and W during cofiring.
Anamorphic lenses for laser diode circularization (2000)

The design, fabrication, and testing of a new anamorphic microlens for laser diode circularization is presented. The microlens is fabricated using photolithography, gray scale masks, and reactive ion etching. A front-to-back mask aligner is used to precisely align two anamorphic aspheric microlenses on opposite sides of a single wafer, creating the ability to circularize or collimate a laser diode with only a single monolithic element. The entire fabrication process is highly nonlinear. This requires that accurate surface metrology methods be incorporated into the process as a feedback loop for iterative corrections to the gray scale mask. We discuss the measurement process and the effects of surface errors for circularizers and circularizer/collimators. This device has been under development for about two years at MEMS Optical. The most recent fabrication and test results of an actual device are presented.
Electron Accumulation Induces Efficiency Bottleneck for Hydrogen Production in Carbon Nitride Photocatalysts (2019)

This study addresses the light intensity dependence of charge accumulation in a photocatalyst suspension, and its impact on both charge recombination kinetics and steady-state H<sub>2</sub> evolution efficiency. Cyanamide surface functionalized melon-type carbon nitride (<sup>NCN</sup>CN<sub><i>x</i></sub>) has been selected as an example of emerging carbon nitrides photocatalysts because of its excellent charge storage ability. Transient spectroscopic studies (from ps to s) show that the bimolecular recombination of photogenerated electrons and holes in <sup>NCN</sup>CN<sub><i>x</i></sub> can be well described by a random walk model. Remarkably, the addition of hole scavengers such as 4-methylbenzyl alcohol can lead to ∼400-fold faster recombination kinetics (lifetime shortening to ∼10 ps). We show that this acceleration is not the direct result of ultrafast hole extraction by the scavenger, but is rather caused by long-lived electron accumulation in <sup>NCN</sup>CN<sub><i>x</i></sub> after hole extraction. The dispersive pseudo-first order recombination kinetics become controlled by the density of accumulated electrons. H<sub>2</sub> production and steady-state spectroscopic measurements indicate that the accelerated recombination caused by electron accumulation limits the H<sub>2</sub> generation efficiency. The addition of a reversible electron acceptor and mediator, methyl viologen (MV<sup>2+</sup>), accelerates the extraction of electrons from the <sup>NCN</sup>CN<sub><i>x</i></sub> and increases the H<sub>2</sub> production efficiency under one sun irradiation by more than 30%. These results demonstrate quantitatively that while long-lived electrons are essential to drive photoinduced H<sub>2</sub> generation in many photocatalysts, excessive electron accumulation may result in accelerated recombination losses and lower performance, and thus highlight the importance of efficient electron and hole extraction in enabling efficient water splitting photocatalysts.
Iron-Catalyzed <i>Ortho</i> C–H Methylation of Aromatics Bearing a Simple Carbonyl Group with Methylaluminum and Tridentate Phosphine Ligand (2016)

Iron-catalyzed C-H functionalization of aromatics has attracted widespread attention from chemists in recent years, while the requirement of an elaborate directing group on the substrate has so far hampered the use of simple aromatic carbonyl compounds such as benzoic acid and ketones, much reducing its synthetic utility. We describe here a combination of a mildly reactive methylaluminum reagent and a new tridentate phosphine ligand for metal catalysis, 4-(bis(2-(diphenylphosphanyl)phenyl)phosphanyl)-N,N-dimethylaniline (Me2N-TP), that allows us to convert an ortho C-H bond to a C-CH3 bond in aromatics and heteroaromatics bearing simple carbonyl groups under mild oxidative conditions. The reaction is powerful enough to methylate all four ortho C-H bonds in benzophenone. The reaction tolerates a variety of functional groups, such as boronic ester, halide, sulfide, heterocycles, and enolizable ketones.
Are <i>N</i>,<i>N</i>-Dihydrodiazatetracene Derivatives Antiaromatic? (2008)

The synthesis and X-ray characterization of two new dialkynylated diazatetracenes and the corresponding N, N-dihydrodiazatetracenes are reported. The dialkynylated heteroacenes are packed in a brick-wall motif that enforces significant overlap of their pi-faces. Cyclic voltammetry indicates that the dehydrogenated forms are easily reduced to their radical anions in solution. The planarity of these species validates the discussion of their aromaticity. Nucleus Independent Chemical Shift (NICS) computations demonstrate that both of these 20 pi and 24 pi electron systems are aromatic. Both experimental and computational results suggest that the aromaticity of the dihydroheteroacenes is reduced.
Portfolio selection with higher moments (2010)

We propose a method for optimal portfolio selection using a Bayesian decision theoretic framework that addresses two major shortcomings of the traditional Markowitz approach: the ability to handle higher moments and parameter uncertainty. We employ the skew normal distribution which has many attractive features for modeling multivariate returns. Our results suggest that it is important to incorporate higher order moments in portfolio selection. Further, our comparison to other methods where parameter uncertainty is either ignored or accommodated in an ad hoc way, shows that our approach leads to higher expected utility than competing methods, such as the resampling methods that are common in the practice of finance.
The antimalarial action of desferal involves a direct access route to erythrocytic (Plasmodium falciparum) parasites. (1993)

We designed the N-methylanthranilic-desferrioxamine (MA-DFO) as a fluorescent iron (III) chelator with improved membrane permeation properties. Upon binding of iron (III), MA-DFO fluorescence is quenched, thus allowing traceability of drug-iron (III) interactions. MA-DFO is well tolerated by mammalian cells in culture. Its antimalarial activity is pronounced: IC50 values on in vitro (24-h) growth of Plasmodium falciparum were 3 +/- 1 microM for MA-DFO compared with 30 +/- 8 for DFO. The onset of growth inhibition of rings or trophozoites occurs 2-4 h after exposure to 13 microM MA-DFO. This effect is commensurate with MA-DFO permeation into infected cells. In a 24-h exposure to MA-DFO or DFO, trophozoites take up either compound to approximately 10% of the external concentration, rings to 5%, and noninfected cells to < 1%. Red cells encapsulated with millimolar concentrations of DFO or MA-DFO fully support parasite invasion and growth. We conclude that extracellular MA-DFO and DFO gain selective access into parasites by bypassing the host. The rate-limiting step is permeation through the parasite membrane, which MA-DFO accomplishes faster than DFO, in accordance with its higher hydrophobicity. These views are consistent with the proposed duct, which apparently provides parasitized cells with a window to the external medium.
Active actuator fault detection and diagnostics in HVAC systems (2012)

This paper introduces a new method for performing actuator fault detection and diagnostics (FDD) in heating ventilation and air conditioning (HVAC) systems. The proposed actuator FDD strategy, for testing whether an actuator is stuck in a single position, uses a two-tier approach that includes a dynamic model-based detector and a fast-deciding steady-state detector. The model-based detector is formulated to provide detection performance that asymptotically bounds both the probability of miss and probability of false alarm. To provide a quick confirmation the actuator is working, the steady-state detector utilizes a goodness-of-fit detection strategy to decide if the measurements could be described by an actuator failure. An architecture is introduced that requires multiple steady-state detection experiments to decide that the measurements could be explained by an actuator failure before performing model-based detection. An experimental test bed using a the KTH Royal Institute of Technology campus HVAC system is described and used to evaluate the steady-state and model-based detectors. The experimental test bed is utilized to identify a building dynamics model, that is employed through monte carlo analysis, to characterize the detection performance of both the model-based detector and the steady-state detector.
Biological stability of polyurethane modified with covalent attachment of di‐<i>tert</i>‐butyl‐phenol (2007)

Polyurethane cardiovascular implants are subject to oxidation initiated surface degradation, which is mediated by monocyte-derived macrophages (MDM); this often leads to surface cracking and device failure. The present studies examined the hypothesis that covalently attaching antioxidant, di-tert-butylphenol (DBP), to the urethane nitrogens of a polyether polyurethane (PU) via bromo-alkylation reactions could prevent this problem. PU was configured with two dosages of DBP, 0.14 mM DBP/g PU of DBP (PU-DBP) and a more highly modified (HM) 0.40 mM DBP/g PU (PU-DBP-HM). THP-1 cells, a human MDM cell line, stimulated with phorbol ester and seeded on PU, PU-DBP, and PU-DBP-HM films were assessed for reactive oxygen species (ROS) production via a fluorescent based dihydrorhodamine-123 assay. Results from these studies showed a significant dose-dependent reduction of ROS levels for THP-1 cells seeded on PU-DBP versus unmodified PU. PU, PU-DBP, or PU-DBP-HM films were implanted into subdermal pouches of Sprague-Dawley rats. Films were explanted after 10 weeks and assessed for oxidative degradation via light and scanning electron microscopy (SEM) and Fourier transformation infrared spectroscopy (FTIR). Light microscopy showed extensive surface cracking, which was confirmed via SEM, on unmodified PU surfaces that was absent in both PU-DBP and PU-DBP-HM explanted films. FTIR analysis showed reduction in oxidation-induced ether crosslinking that was directly related to DBP dosages. It is concluded that modifying PU with the covalent attachment of an antioxidant confers biodegradation resistance in vivo in a dose dependent manner; this effect is likely due to quenching of the ROS generated by the adherent macrophages.
[Prokaryotic expression, purification and preparation of polyclonal antibody for wheat grain peroxidase WP1 gene]. (2011)

Wheat peroxidases 1 (WP1) is the major cationic peroxidase of wheat (Triticum aestivum) grain, which is involved in the development of seeds and an important factor to affect the final processing quality of flour. We constructed a prokaryotic expression vector pET28a-WP1, and transformed it into E. coli host strain T7 Expression. His-tag fused WP1 existed as inclusion body, and the recombinant protein was purified by Ni-NTA resin affinity chromatography under denatured condition. The purity of target protein reached 98%. The recombinant WP1 was refolded by gradient urea dialysis, then used as antigen to immune rabbit to prepare polyclonal antibody. The result of ELISA showed that the titer of rabbit anti-WP1 antiserum was higher than 1:625 000. The result of Western blotting demonstrated that the prepared WP1 polyclonal antibody could be used to detect WP1 with high specificity.
On the Luminescent Properties of the Rare Earth Vanadates (1965)

X‐ray examination of several systems indicated that compounds of the type are the only ones formed by the rare earth sesquioxides and vanadium pentoxide. On the basis of this finding, we developed a flux‐growing technique employing a melt for the preparation of all rare earth vanadates in single crystalline form. With such monocrystals as well as with polycrystalline material we studied the fluorescent emission of the rare earth vanadates, and these data are reported and discussed.
Analysis of sampling algorithms for twitter (2015)

The daily volume of Tweets in Twitter is around 500 million, and the impact of this data on applications ranging from public safety, opinion mining, news broadcast, etc., is increasing day by day. Analyzing large volumes of Tweets for various applications would require techniques that scale well with the number of Tweets. In this work we come up with a theoretical formulation for sampling Twitter data. We introduce novel statistical metrics to quantify the statistical representativeness of the Tweet sample, and derive sufficient conditions on the number of samples needed for obtaining highly representative Tweet samples. These new statistical metrics quantify the representativeness or goodness of the sample in terms of frequent keyword identification and in terms of restoring public sentiments associated with these keywords. We use uniform random sampling with replacement as our algorithm, and sampling could serve as a first step before using other sophisticated summarization methods to generate summaries for human use. We show that experiments conducted on real Twitter data agree with our bounds. In these experiments, we also compare different kinds of random sampling algorithms. Our bounds are attractive since they do not depend on the total number of Tweets in the universe. Although our ideas and techniques are specific to Twitter, they could find applications in other areas as well.
Microbial hydroxylation of steroids. 8. Incubation of Cn halo- and other substituted steroids with Cn hydroxylating fungi (1982)

A series of C-21 substituted progesterone derivatives (R = F, Cl, Br, CH 3 ) has been prepared, and incubated the C-21 hydroxylating fungus A. niger. No biotransformation was observed where R = Cl, Br, or CH 3 , but a minor amount of hydroxylation occurred at an unidentified site where R = F. Two C-11β substituted progesterone derivatives (R = F, OH) were converted to the corresponding C-11 ketone by the C-11α hydroxylator R. stolonifer, but a C-11β hydroxylator (C. lunata) was unable to perform a similar transformation with a C-11α hydroxy substrate. C. lunata hydroxylated a C-11β fluoro substrate at C-14α and C-21 in low yield. C-7α and -7β-hydroxy androst-4-ene-3,17-diones were prepared and incubated with C-7β hydroxylating (R. stolonifer) and C-7α hydroxylating (M. griseocyanus) fungi respectively. No ketone formation was observed. Similarly, the C-6β hydroxylator R. arrhizus was unable to transform a C-6α-hydroxy substrate or C-6α- or C-6β-hydroxy-B-norsteroids. No oxidation at halogen was observed for any of the substrates used. 13 C– 19 F coupling constants for 11β-fluoroprogesterone suggest the presence of through space interactions between fluorine and both C-18 and C-19.
Progress in large-area CIGS-based modules with sputtered-GZO window (2003)

An objective of this study is to reduce the efficiency gap of 30 cm/spl times/ 30 cm-sized CIGS-based thin-film modules with MOCVD-ZnO:B or sputtered-5.7GZO (ZnO:5.7wt%Ga) window. Based upon a growth model of MOCVD-ZnO:B window, a thin intrinsic-ZnO layer with the thickness of 50 nm is prepared on a CBD-Zn(O,S,OH)/sub x/ buffer by RIF sputtering in the case of sputtered-5.7GZO window. This approach contributes to maintain the reproducibility of our current baseline process and leads to the achievement of the module efficiency of 12.2 % with this window, which has been measured by NREL. It is emphasized that 1) this gap is reduced up to 1 % by making a module, and 2) low-cost packaging technologies without any J/sub sc/ loss and suitable to CIGS-based thin-film circuits should be developed promptly.
Study of the demolding process—implications for thermal stress, adhesion and friction control (2006)

With the improvements of large-scale parallel replication and automation for hot embossing machines, hot embossing has become not only popular in laboratories but also possible and attractive in industry. Most difficulties in polymer micro-molding are caused by the demolding of molds rather than the filling of them. Due to the lack of accurate analysis tools and simulation tools for demolding, it is difficult to improve the process or give design rules for the molds, which could harm the further applications of hot embossing. This paper gives our studies of the demolding process using LIGA mold inserts. The demolding forces mainly consist of thermal shrinkage stress and adhesive forces. First, a finite elements method (FEM) is applied to analyze thermal stress caused by the shrinkage differences between the mold and polymer using ABAQUS/Standard, and a thermal stress barrier is proposed as an auxiliary structure to protect against the converging stress at the bottom corner of microstructures. Then, regarding the adhesion and friction forces, the nanotribology of PMMA is studied by AFM with nickel and PTFE-coated Si3N4 tips. And based on the measurements, the adhesion and friction forces in a demolding cycle are also simulated by FEM using ABAQUS/Standard. At last Ni-PTFE is recommended as the mold material for achieving a lower surface energy and lower friction force. This work proposes several methods that can optimize the demolding process and introduces some good suggestions for mold tool design.
Chemistry of tropan-3-yl ethers. Part I. Synthesis of tropan-3-yl ethers (1971)

Tropan-3α-yl methanesulphonate reacts with sodium alcoxides or phenoxides to form tropan-3β-yl ethers with inversion at C-3. The reaction of 3α-chlorotropane with sodium phenoxides or benzyl oxide leads to tropan-3α-yl ethers. The configuration at C-3 of the alkyl and benzyl tropan-3-yl ethers has been established by chemical methods.