gebhart/patrepeval huggingface dataset:
Lead-free and halogen free solder flip chips on board using SMT processes and materials for miniaturization and lower cost (2013)

Miniaturization and the integration of a growing number of functions in portable electronic devices require an extremely high packaging density for the active and passive components. There are many ways to increase the packaging density and a few examples would be to stack them such as with Package on Package (PoP), fine pitch CSP's or solder flipchip on board. This means that the size and pitch of solder balls or pads in the electronic component packages will continue to shrink and that component stacking with so called Package on Package (PoP) and fine-pitch CSP's will continue to be heavily used. Another important factor is that not only is the area density increasing and the drive to make portable electronics thinner also drives thinner components and thereby warpage becomes one of the key challenges. The use of fine pitch CSP and PoP component's, equal and below 0.40mm pitch, poses a number of challenges for PCB Design, SMT Assembly process and Reliability and since the assembly methods and requirements of these are very similar to lead-free solder flipchips this means lead-free solder flipchip on board can be implemented into high volume consumer products at minimal extra cost of process or materials such as flux underfill and last but not least the cost of printed circuit boards. First, a feasible assembly process must be achieved. The assembly process ranges all the way from screen-printing, dipping in flux or paste, reflow soldering in air or nitrogen and underfill. Many factors influence the quality of the assembly process and with the reduced pitch, the process capabilities for both assembly and PCB fabrication will be tested to its limit and beyond. The basic processes to control are screen-printing, pick & place, reflow soldering with the aid of Nitrogen and underfill and by using solder flipchip some of the challenges can actually be eliminated but there will also be some extra challenges such as known good die, wafer feeding and others. Second, the correct incoming materials such as PCB material, PCB surface finish, solder paste, dipping flux, underfill and PCB design need to be selected to ensure a high yielding, cost effective and reliable interconnects. Of course, the mechanics of the products makes a big difference as well but it is very product dependent and many of today's products leave little room for designing the mechanics in the most reliable way due to total cost and overall look and size of the products This paper will discuss different design & layout alternatives and assembly & material selection alternatives for using 0.18mm pitch solder flipchips instead of 0.30-0.40mm pitch CSP's and their corresponding challenges. Different flux and underfill materials are evaluated for compatibility with the lead-free solder and halogen free materials and processes. Results from assembly and reliability testing will be presented, in comparison with 0.30mm pitch CSP's on halogen free FR4 substrates with and without underfill.
Magnetic Dipole Inflation with Cascaded Arc and Applications to Mini-Magnetospheric Plasma Propulsion (2003)

Mini-Magnetospheric Plasma Propulsion (M2P2) seeks to create a plasma-inflated magnetic bubble capable of intercepting significant thrust from the solar wind for the purposes of high speed, high efficiency spacecraft propulsion. Previous laboratory experiments into the M2P2 concept have primarily used helicon plasma sources to inflate the dipole magnetic field. The work presented here uses an alternative plasma source, the cascaded arc, in a geometry similar to that used in previous helicon experiments. Time resolved measurements of the equatorial plasma density have been conducted and the results are discussed. The equatorial plasma density transitions from an initially asymmetric configuration early in the shot to a quasisymmetric configuration during plasma production, and then returns to an asymmetric configuration when the source is shut off. The exact reasons for these changes in configuration are unknown, but convection of the loaded flux tube is suspected. The diffusion time was found to be an order of magnitude longer than the Bohm diffusion time for the period of time after the plasma source was shut off. The data collected indicate the plasma has an electron temperature of approximately 11 eV, an order of magnitude hotter than plasmas generated by cascaded arcs operating under different conditions. In addition, indirect evidence suggests that the plasma has a beta of order unity in the source region.
<title>MPEG-4 low-delay general audio coding</title> (2001)

Traditionally, speech coding for communication purposes and perceptual audio coding have been separate worlds. On one hand, speech coders provide acceptable speech quality at very low data rates and low delays which are suitable for two-way communication applications, such as Voice over IP (VoIP) or teleconferencing. Due to the underlying coding paradigm, however, such coders do not perform well for non-speech signals (e.g.~music and environmental noise). Furthermore, the sound quality and naturalness is severely limited by the fact that most coders are working in narrow-band mode, i.e. with a bandwidth below 4 kHz. On the other hand, perceptual audio codecs provide excellent subjective audio quality for a broad range of signals including speech at bit rates down to 16 kbit/s. The delay of such a coder/decoder chain, however, usually exceeds 200 ms at very low data rates and in this way is not acceptable for interactive two-way communication. This paper describes a coding scheme which is designed to combine the advantages of perceptual audio coding with the low delay necessary for two-way communication. The codec was standardized within MPEG-4 Version 2 Audio under the work item ``Low Delay Audio Coding'' and is derived from the ISO/MPEG-2/4 Advanced Audio Coding (AAC) algorithm. The algorithm provides modes operating at algorithmic delay as low as 20 ms and is equipped to handle all full-bandwidth high-quality audio signals, both in monophonic, stereophonic and even multi-channel format. Despite of the low algorithmic delay, the codec delivers better audio quality than MPEG-1 Layer-3 (MP3) at the same bit rate. The paper also addresses issues pertaining to the integration of the coder into H.32x and SDP applications.
Kinetics and Mechanism of Turanite Reduction by Hydrogen (2020)

Turanite, Cu5(VO4)2(OH)4, is a naturally occurring mineral whose physical and chemical properties are of interest for magnetic data storage, battery applications, and catalysis. In this study, the reduction of nanostructured Cu5(VO4)2(OH)4 by H2 is investigated using a combination of scanning transmission electron microscopy–electron energy-loss spectroscopy, X-ray photoelectron spectroscopy, in situ diffuse reflectance infrared Fourier transform spectroscopy, in situ X-ray absorption spectroscopy, first-principles calculations, and kinetic analysis based on thermogravimetry. A two-step mechanism is proposed, in which Cu5(VO4)2(OH)4 is first reduced, following exponential growth kinetics, to form a stable intermediate consisting of a mix of Cu3VO4, Cu2O, and CuV2O5. The intermediate phase is then subsequently reduced in a 3-D diffusion-limited process to form two segregated phases consisting of Cu metal and V2O3 particles. The apparent energy barriers for these two steps, obtained from the kinetic analysis, were found to be 52.5 and 71.2 kJ mol–1 for Stages 1 and 2 of the reduction, respectively. These results highlight the importance of developing a rigorous understanding of the reduction processes involved in metal oxide catalyst preparation.
Multilayer Nb&lt;inf&gt;3&lt;/inf&gt;Sn superconducting shields (1985)

Multilayer Nb <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> Sn shields have been designed, fabricated, and tested for use in low field, e.g. superconducting electronics, applications. Magnetic field profiles, shielding factors, and thermal effects are reported for these shields. The quality of the shields depends strongly on the reaction temperature used to form the Nb <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> Sn layers with lower reaction temperatures forming better quality shields. Nearly ideal behavior was observed with a reaction temperature of 750°C.
Complexity Reduction Techniques for the Compression of High-Definition Video (2009)

The state-of-the-art video compression standard, the hybrid predictive-transform H.264/AVC codec, has lead to substantial performance improvement compared to other existing standards. Performing predictions is a computational demanding task and optimizing this stage may result in substantial encoding speedup. In this paper, we propose more efficient approaches to implement the H.264/AVC prediction stage. The first idea is to use original data rather than reconstructed ones to perform prediction tests before choosing the best mode. The residue, however, is evaluated using previously decoded data in order to avoid drifting. The second approach is to employ a subset of dominant prediction modes instead of testing all modes recommended by the H.264/AVC standard. The subset is updated frame-by-frame using macroblock sampling. Results for high definition sequences show that the quality loss is negligible allowing us not only to parallelize the inter-prediction stage but also to reduce total complexity.
Cloning and DNA sequence analysis of an aac(3)-Vb gene from Serratia marcescens (1992)

The AAC(3)-V resistance mechanism is characterized by high-level resistance to the aminoglycosides gentamicin, netilmicin, 2'-N-ethylnetilmicin, and 6'-N-ethylnetilmicin and moderate resistance levels to tobramycin. Serratia marcescens 82041944 contains an AA(3)-V resistance mechanism as determined from aminoglycoside resistance profiles. This strain, however, does not exhibit hybridization with a probe derived from the previously cloned aac(3)-Va gene, (R. Allmansberger, B. Bräu, and W. Piepersberg, Mol. Gen. Genet. 198:514-520, 1985). High-pressure liquid chromatography analysis of the acetylation products of sisomicin carried out by extracts of S. marcescens 82041944 have demonstrated the presence of an AAC(3) enzyme. We have cloned the gene encoding this acetyltransferase and have designated it aac(3)-Vb. Nucleotide sequence comparisons show that the aac(3)-Va and aac(3)-Vb genes are 72% identical. The predicted AAC(3)-Vb protein is 28,782 Da. Comparisons of the deduced amino acid sequences show 75% identity and 84% similarity between the AAC(3)-Va and AAC(3)-Vb proteins. The use of a DNA fragment internal to the aac(3)-Vb as a hybridization probe demonstrated that the aac(3)-Vb gene is very rare in clinical isolates possessing an AAC(3)-V mechanism.
Critical slowing down and hyperuniformity on approach to jamming (2016)

Hyperuniformity characterizes a state of matter that is poised at a critical point at which density or volume-fraction fluctuations are anomalously suppressed at infinite wavelengths. Recently, much attention has been given to the link between strict jamming (mechanical rigidity) and (effective or exact) hyperuniformity in frictionless hard-particle packings. However, in doing so, one must necessarily study very large packings in order to access the long-ranged behavior and to ensure that the packings are truly jammed. We modify the rigorous linear programming method of Donev et al. [J. Comput. Phys. 197, 139 (2004)JCTPAH0021-999110.1016/j.jcp.2003.11.022] in order to test for jamming in putatively collectively and strictly jammed packings of hard disks in two dimensions. We show that this rigorous jamming test is superior to standard ways to ascertain jamming, including the so-called "pressure-leak" test. We find that various standard packing protocols struggle to reliably create packings that are jammed for even modest system sizes of N≈10^{3} bidisperse disks in two dimensions; importantly, these packings have a high reduced pressure that persists over extended amounts of time, meaning that they appear to be jammed by conventional tests, though rigorous jamming tests reveal that they are not. We present evidence that suggests that deviations from hyperuniformity in putative maximally random jammed (MRJ) packings can in part be explained by a shortcoming of the numerical protocols to generate exactly jammed configurations as a result of a type of "critical slowing down" as the packing's collective rearrangements in configuration space become locally confined by high-dimensional "bottlenecks" from which escape is a rare event. Additionally, various protocols are able to produce packings exhibiting hyperuniformity to different extents, but this is because certain protocols are better able to approach exactly jammed configurations. Nonetheless, while one should not generally expect exact hyperuniformity for disordered packings with rattlers, we find that when jamming is ensured, our packings are very nearly hyperuniform, and deviations from hyperuniformity correlate with an inability to ensure jamming, suggesting that strict jamming and hyperuniformity are indeed linked. This raises the possibility that the ideal MRJ packings have no rattlers. Our work provides the impetus for the development of packing algorithms that produce large disordered strictly jammed packings that are rattler free, which is an outstanding, challenging task.
Energy Transfer between Conjugated Polyelectrolytes in Layer-by-Layer Assembled Films (2011)

We present a study of Förster resonance energy transfer (FRET) between two emissive conjugated polyelectrolytes (CPEs) in layer-by-layer (LbL) self-assembled films as a means of examining their organization and architecture. The two CPEs are a carboxylic acid functionalized polyfluorene (PFl-CO(2)) and thienylene linked poly(phenylene ethynylene) (PPE-Th-CO(2)). The PFl-CO(2) presents a maximum emission at 418 nm, while the PPE-Th-CO(2) has an absorption λ(max) centered at 431 nm, in sufficient proximity for effective FRET. Several LbL films have been constructed using varied concentrations of the deposition solutions and identity of the buffer layers separating the two emissive layers, using a system of either weak polyelectrolytes, poly(allylamine hydrochloride) (PAH)/poly(sodium methacrylate) (PMA), or strong polyelectrolytes, poly(diallylammonium chloride) (PDDA)/poly(styrene sulfonate) sodium (PSS). The efficiency of FRET has been monitored using fluorescence spectroscopy. Initially, the fluorescence of the PFl-CO(2) (E(g) ∼ 3.0 eV), which emits at 420 nm, is quenched by the lower band gap PPE-Th-CO(2) (E(g) ∼ 2.5 eV). For films using the PAH/PMA system as buffer bilayers and deposited from 1 mM solutions, the PFl-CO(2) fluorescence is progressively recovered as the number of intervening buffer bilayers is increased. Ellipsometry measurements indicate that energy transfer between the two emissive layers is efficient to a distance of ca. 7 nm.
Functionalized Ruthenium Dialkynyl Complexes with High Second-Order Nonlinear Optical Properties and Good Potential as Dye Sensitizers for Solar Cells (2014)

Various dipolar π-delocalized Ru(II) dialkynyl complexes were prepared and characterized. Their second-order nonlinear optical (NLO) properties were investigated by the electric-field-induced second harmonic generation (EFISH) technique working in CH2Cl2 solution with an incident wavelength of 1907 nm, whereas the dipole moments were determined by density functional theory (DFT) calculations. All the investigated complexes are characterized by a negative value of μβ1.907 EFISH, in agreement with a negative value of Δμeg (difference of the dipole moment in the excited and ground state) upon excitation. Their second-order NLO response can be easily modulated by the nature of the alkynyl substituents. Besides, the most promising “push–pull” ruthenium diacetylide complex, adequately functionalized for anchoring to TiO2, was tested as photosensitizer in dye-sensitized solar cells (DSSCs).
Review of Current Strategies for Delivering Alzheimer's Disease Drugs Across the Blood-Brain Barrier (2022)

(Appeared originally in the International Journal of Molecular Sciences 2019; 20:381) Reprinted under Creative Commons CC-BY license.
Grid Search Optimization (2015)

From the Washington University Undergraduate Research Digest: WUURD, Volume 10, 2014-2015. Published by the Office of Undergraduate Research, Joy Zalis Kiefer Director of Undergraduate Research and Assistant Dean in the College of Arts & Sciences; Stacy Ross, Editor; Kristin Sobotka, Editor; Jennifer Kohl. Mentor: Zachary Feinstein
Nanowire decorated, ultra-thin, single crystalline silicon for photovoltaic devices (2017)

Reducing silicon (Si) wafer thickness in the photovoltaic industry has always been demanded for lowering the overall cost. Further benefits such as short collection lengths and improved open circuit voltages can also be achieved by Si thickness reduction. However, the problem with thin films is poor light absorption. One way to decrease optical losses in photovoltaic devices is to minimize the front side reflection. This approach can be applied to front contacted ultra-thin crystalline Si solar cells to increase the light absorption. In this work, homojunction solar cells were fabricated using ultra-thin and flexible single crystal Si wafers. A metal assisted chemical etching method was used for the nanowire (NW) texturization of ultra-thin Si wafers to compensate weak light absorption. A relative improvement of 56% in the reflectivity was observed for ultra-thin Si wafers with the thickness of 20 ± 0.2 μm upon NW texturization. NW length and top contact optimization resulted in a relative enhancement of 23% ± 5% in photovoltaic conversion efficiency.
Harnessing Plasmon-Induced Ionic Noise in Metallic Nanopores (2013)

The ionic properties of a metal-coated silicon nanopore were examined in a nanofluidic system. We observed a strong increase of the ionic noise upon laser light illumination. The effect appeared to be strongly mediated by the resonant excitation of surface plasmons in the nanopore as was demonstrated by means of ionic mapping of the plasmonic electromagnetic field. Evidence from both simulations and experiments ruled out plasmonic heating as the main source of the noise, and point toward photoinduced electrochemical catalysis at the semiconductor-electrolyte interface. This ionic mapping technique described is opening up new opportunities on noninvasive applications ranging from biosensing to energy conversion.
Morphological Disambiguation by Voting Constraints (1997)

We present a constraint-based morphological disambiguation system in which individual constraints vote on matching morphological parses, and disambiguation of all the tokens in a sentence is performed at the end by selecting parses that receive the highest votes. This constraint application paradigm makes the outcome of the disambiguation independent of the rule sequence, and hence relieves the rule developer from worrying about potentially conflicting rule sequencing. Our results for disambiguating Turkish indicate that using about 500 constraint rules and some additional simple statistics, we can attain a recall of 95-96% and a precision of 94-95% with about 1.01 parses per token. Our system is implemented in Prolog and we are currently investigating an efficient implementation based on finite state transducers.
Atomic Force Microscopy Observations of Si Surfaces after Rinsing in Ultrapure Water with Low Dissolved Oxygen Concentration (1997)

Contact‐mode and tapping‐mode atomic force microscopy have been used to observe hydrogen‐terminated (111) and (001) Si surfaces. The surfaces were prepared by rinsing in ultrapure water with very low dissolved oxygen after removal of the native oxide using 1% HF acid at room temperature. With the tapping‐mode atomic force microscopy, clear steps and triangular‐shaped holes were observed on the (111) Si surface. The step shape varied according to the misorientation angle of the sample. The (001) Si surface consisted of round‐shaped "mountains." The roughness of the (001) surface increased with longer rinsing in ultrapure water. This type of Si surface etching is very similar to that observed in the case of etching with solution (pH 8).
Etude de la croissance des nanotubes de Carbone par PECVD en fonction du temps selon différents paramètres expérimentaux (2014)

International audience
Angiotensin II stimulates T-type Ca2+ channel currents via activation of a G protein, Gi (1996)

Angiotensin II (ANG II) is the most potent and the most physiologically important stimulator of aldosterone synthesis and secretion from the adrenal zona glomerulosa. Because steroidogenesis by adrenal glomerulosa (AG) cells is mediated in part by Ca2+ influx through T- and L-type Ca2+ channels, we evaluated whether T-type Ca2+ channels are regulated by ANG II. We observe that ANG II enhances T-type Ca2+ current by shifting the voltage dependence of channel activation to more negative potentials. This shift is transduced by the ANG II type 1 receptor. The effect of the hormone is not mediated by Ca2+/calmodulin-dependent protein kinase II (CaMKII) as it is not prevented by CaMKII(281-302), a peptide inhibitor of the catalytic region of the kinase. Rather, this shift is mediated by the activation of a G protein, Gi, because it is abolished by cell pretreatment with pertussis toxin and by cell dialysis with a monoclonal antibody generated against recombinant Gi alpha. This effect of ANG II on T-type Ca2+ channels should increase Ca2+ entry in AG cells at physiologically relevant voltages and result in a sustained increase in aldosterone secretion.
Spatial distribution of meteorological parameters around 900 hPa level over the Arabian Sea and Indian Ocean regions during the Intensive Field Phase - 99 of the INDOEX programme (2001)

During the IFP-99 of the INDOEX programme, an Indo-French joint scientific team conducted 17 constant
balloon flights from Goa mainly to study the various features of the continental air mass flow from
the Indian subcontinent towards the ITCZ induced by the NE winter circulation and thereby to derive the
transportation of the continental aerosols and trace gases to the Indian Ocean regions. Out of the 17
flights, 15 were successful. Data obtained from the Constant Altitude Balloon Experiment are analysed
to study the features of the wind fields and thermodynamic parameters of the marine boundary layer at
~ 900 hPa level over the oceanic regions adjoining west-coast of Peninsular India. From the balloon
co-ordinates, the instantaneous vector wind as well as its zonal and meridional components are estimated.
Also estimated are the ambient air temperature and relative humidity at 30 min interval. These data are examined for the spatial features. Mean wind showed presence of three broad flow channels, from India, Africa and West Asia, that are important in influencing the Arabian Sea environment and provide potential pathways for transport of continental pollutants. Variations associated with the M.) oscillations
are present in the zonal wind, close to the equator. On several occasions wind showed occurrence of eddies with anticyclonic circulation having temporal scales of one to five days. Temperature and humidity structure showed large dry areas over the Arabian Sea associated with the flow channels. Rather humid regions occur over coastal India and near the ITCZ.
Enzymatic incorporation of an unnatural base pair between 4-propynyl-pyrrole-2-carbaldehyde and 9-methyl-imidazo[(4,5)-b]pyridine into nucleic acids (2002)

A hydrophobic unnatural nucleoside of 4-propynylpyrrole-2-carbaldehyde (designated as Pa') was synthesized to improve its affinity with a pairing partner, 9-methyl-imidazo[(4,5)-b]pyridine (Q), in enzymatic incorporation. In single-nucleotide insertion experiments using the Klenow fragment, the substrate of Pa' (dPa'TP) was efficiently incorporated opposite Q in the template strand, as compared to the incorporation of pyrrole-2-carbaldehyde (dPaTP), which was previously developed.