gebhart/patrepeval huggingface dataset:
Morphology, structure and electrical properties of iron nanochains (2006)

Iron nanoparticles with a diameter of 35 nm are synthesized by the thermal decomposition of iron pentacarbonyl in a hot wall reactor. The particles are ferromagnetic and single magnetic domain. The magnetic forces between the particles cause the formation of iron nanowires of up to 300 µm in length. Morphological characterization using high resolution transmission electron microscopy indicates an oxidic shell with a thickness of 3–4 nm. The electrical properties of single chains are investigated under air using impedance spectroscopy (IS). It is found that the conductivity of the iron is in the same range as that of the bulk material. Temperature dependent measurements on iron nanochain powders performed under H2-atmosphere reveal strong sintering effects and a transition into iron.
A 4 GHz phase locked loop design in 65 nm CMOS for the Jiangmen Underground Neutrino Observatory detector (2018)

This paper presents a 4 GHz phase locked loop (PLL), which is implemented in a 65 nm standard CMOS process to provide low noise and high frequency sampling clocks for readout electronics to be used in the Jiangmen Underground Neutrino Observatory (JUNO) experiment. Based on the application requirements the target of the design is to find the best compromise between power consumption, area and phase noise for a highly reliable topology. The design implements a novel method for the charge pump that suppresses current mismatch when the PLL is locked. This reduces static phase offset at the inputs of the phase-frequency detector (PFD) that otherwise would introduce spurs at the PLL output. In addition, a technique of amplitude regulation for the voltage controlled oscillator (VCO) is presented to provide low noise and reliable operation. The combination of thin and thick oxide varactor transistors ensures optimum tuning range and linearity over process as well as temperature changes for the VCO without additional calibration steps. The current mismatch at the output of the charge pump for the control voltage at about half the 1 V supply voltage is below 0.3% and static phase offset down to 0.25% is reached. The total PLL consumes 18.5 mW power at 1.8 V supply for the VCO and 1 V supply for the other parts.
Lifetime extension of a multi-die SiC power module using selective gate driving with temperature feedforward compensation (2017)

Owing to the high current density but smaller die area of SiC components, high current SiC power modules typically feature a large number of parallel connected dies. Due to the faster electrical dynamics of these power modules, and the inherent mismatch of properties between the dies, certain dies can be poorly utilized - requiring either more dies to achieve a given current rating or a de-rating of the current handling capability of that module. This paper investigates the use of integrated per-die buffers with selective gate driving to minimize the thermal differences within a high current SiC power module. The predetermined selective gate driving pattern is based on the steady-state temperature distribution of the power module, and hence is used as a feed-forward term to compensate the thermal unbalance. The experimental results demonstrate a drop of 15°C in the hottest die using selective gate driving, corresponding to a lifetime increase of up to 3 times, according to the case study presented.
Power Amplifier Design Considerations for RF and mmW Embedded Systems (2010)

International audience
Microstructural Effects on Hydrogen – Assisted Fracture of Austenitic Stainless Steel Welds (2004)

Abstract A multiple-pass gas tungsten arc weld in 22Cr - 13Ni - 5Mn austenitic stainless steel with matching filler exhibited dramatically reduced fracture toughness relative to the base material. This reduction in toughness was exacerbated by 6500 appm of thermally charged hydrogen. Optical and scanning electron microscopy revealed that significant amounts of the ferrite present in the weld deposit had transformed to the brittle intermetallic sigma phase as a result of the heat input of successive weld passes. Examination of the fracture surfaces and sub-surface regions showed that the lower fracture toughness of the uncharged weld could be attributed primarily to microvoid nucleation, growth, and coalescence associated with both manganese sulfide inclusions and cracking of the sigma phase particles. The presence of hydrogen increased the propensity for low-plasticity fracture, and it is proposed that this increase may be due to enhanced fracture along austenite – ferrite interfaces and through the ferrite dendritic structure, followed by linking of damage sites ahead of the crack tip by hydrogen-enhanced shear failure.
The State of the Art in Single-Column Ion Chromatography (1986)

Journal Article The State of the Art in Single-Column Ion Chromatography Get access Thomas H. Jupille, Thomas H. Jupille Wescan Instruments, Inc., 3018 Scott Blvd., Santa Clara, California 95054 Search for other works by this author on: Oxford Academic PubMed Google Scholar Douglas T. Gjerde Douglas T. Gjerde Wescan Instruments, Inc., 3018 Scott Blvd., Santa Clara, California 95054 Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Chromatographic Science, Volume 24, Issue 10, October 1986, Pages 427–433, https://doi.org/10.1093/chromsci/24.10.427 Published: 01 October 1986 Article history Received: 30 September 1985 Revision received: 24 June 1986 Published: 01 October 1986
Therapeutic Arteriogenesis by Ultrasound-Mediated VEGF 165 Plasmid Gene Delivery to Chronically Ischemic Skeletal Muscle (2007)

Current methods of gene delivery for therapeutic angiogenesis are invasive, requiring either intraarterial or intramuscular administration. A noninvasive method of gene delivery has been developed using ultrasound-mediated destruction of intravenously administered DNA-bearing carrier microbubbles during their microcirculatory transit. Here we show that chronic ischemia could be markedly improved by ultrasound-mediated destruction of microbubbles bearing vascular endothelial growth factor-165 (VEGF(165)) plasmid DNA. Using a model of severe chronic hindlimb ischemia in rats, we demonstrated that ultrasound mediated VEGF(165)/green fluorescent protein (GFP) plasmid delivery resulted in a significant improvement in microvascular blood flow by contrast-enhanced ultrasound, and an increased vessel density by fluorescent microangiography, with minimal changes in control groups. The improvement in tissue perfusion was attributed predominantly to increases in noncapillary blood volume or arteriogenesis, with perfusion peaking at 14 days after delivery, followed by a partial regression of neovascularization at 6 weeks. Transfection was localized predominantly to the vascular endothelium of arterioles in treated ischemic muscle. RT-PCR confirmed the presence of VEGF(165)/GFP mRNA within treated ischemic muscle, being highest at day 3 postdelivery, and subsequently decreasing, becoming almost undetectable by 6 weeks. We found a modulation of endogenous growth factor expression in VEGF-treated ischemic muscle, consistent with a biologic effect of ultrasound mediated gene delivery. The results of our study demonstrate the utility of ultrasonic destruction of plasmid-bearing microbubbles to induce therapeutic arteriogenesis in the setting of severe chronic ischemia.
Modulation of Insulin Secretion by Insulin and Glucose in Type II Diabetes Mellitus* (1985)

We studied the dose-response characteristics of insulin's ability to modulate its own secretion in normal and type II diabetic (NIDDM) subjects by measuring suppression of serum C-peptide levels during insulin infusions with the plasma glucose level held constant. In normal subjects at euglycemia, primed continuous insulin infusion rates of 15, 40, 120, and 240 mU/M2 X min acutely raised serum insulin to steady state levels of 37 +/- 2 (+/- SE), 96 +/- 6, 286 +/- 17, and 871 +/- 93 microU/ml, respectively. During each infusion, maximal suppression of C-peptide to 30% of basal levels occurred by 130 min. At the higher insulin levels (greater than or equal to 100 microU/ml), C-peptide levels fell rapidly, with an apparent t1/2 of 13 min, which approximates estimates for the t1/2 of circulating C-peptide in man. This is consistent with an immediate 70% inhibition of the basal rate of insulin secretion. At the lower insulin level (37 +/- 2 microU/ml), C-peptide levels fell to 30% of basal values less rapidly (apparent t1/2, 33 min), suggesting that 70% inhibition of basal insulin secretion rates was achieved more slowly. In NIDDM subjects, primed continuous insulin infusion rates of 15, 40, 120, and 1200 mU/M2 X min acutely raised serum insulin to steady state levels of 49 +/- 7, 93 +/- 11,364 +/- 31, and 10,003 +/- 988 microU/ml. During studies at basal hyperglycemia, only minimal C-peptide suppression was found, even at pharmacological insulin levels (10,003 +/- 988 microU/ml). However, if plasma glucose was allowed to fall during the insulin infusions, there was a rapid decrease in serum C-peptide to 30% of basal levels, analogous to that in normal subjects. Three weeks of intensive insulin therapy did not alter C-peptide suppression under conditions of hyperinsulinemia and falling plasma glucose. The following conclusions were reached. 1) In normal subjects, insulin (40-1000 microU/ml) inhibits its own secretion in a dose-responsive manner; more time is required to achieve maximal 70% suppression at the lower insulin level (40 microU/ml). 2) In NIDDM studied at basal hyperglycemia, insulin has minimal ability to suppress its own secretion. Thus, impaired feedback inhibition could contribute to basal hyperinsulinemia. 3) Under conditions of hyperinsulinemia and falling plasma glucose, insulin secretion is rapidly suppressed in NIDDM (analogous to that in normal subjects studied during euglycemia.
Improved Photocatalytic Hydrogen Evolution on Tantalate Perovskites CsTaO3 and LiTaO3 by Strain-Induced Vacancies (2020)

Tantalate perovskites are potential candidates for photocatalytic hydrogen production without cocatalyst addition; however, these oxides have large bandgaps, which result in their low photocatalytic activity. In this study, to enhance the photocatalytic activity, CsTaO3 as a potential photocatalyst and LiTaO3 as a well-known photocatalyst are subjected to severe plastic strain using the high-pressure torsion (HPT) method. Both superstrained tantalates exhibit optical bandgap narrowing and ∼2.5 times enhancement of photocatalytic hydrogen production. Such bandgap narrowing is mainly due to the formation of oxygen vacancies, although nanocrystal formation and partial amorphization also occur by straining. These findings not only introduce CsTaO3 as a photocatalyst but also confirm the significance of strain-induced vacancies on the photocatalytic activity of perovskites.
Patience Alone is not Enough – A Guide for the Preparation of Low-Defect Sections from Pure Copper (2021)

Abstract The preparation of metallographic sections from soft metals such as pure copper constitutes a particular challenge: the high degree of ductility promotes the formation of preparation artifacts and complicates the preparation of homogeneous, low-deformation surfaces. A metallographic preparation routine is therefore presented which has proven effective for pure copper and which can also be applied to additionally soft annealed samples. The subsequent removal of fine crystalline deformation layers is discussed and different setups for electropolishing and its optimization are presented.
On anisotropic tensile mechanical behavior of Al–Cu–Li AA2198 alloy under different ageing conditions (2023)

The anisotropic mechanical behavior of Al–Cu–Li (AA2198) alloy under different artificial ageing conditions as well as for different thicknesses of the material was examined in the present investigation. Material characterization was performed for three different sheet directions, namely, longitudinal (0°), diagonal (45°) and transverse (90°) to the rolling direction. The results showed that the grain structure did not have significant changes by applying different artificial ageing times. In T3 heat treatment condition, only δ′ (Al3Li) phase was observed, while with increasing the ageing time, the major precipitates were T1 (Al2CuLi) phases. The latter was found to increase in size with artificial aging time. Almost similar yield strength values were observed for all investigated thicknesses, while the higher thickness specimens showed higher elongation at fracture values. Anisotropy was slightly higher at T3 condition, while the lowest anisotropy degree was noticed at the peak-aged condition. The specimens extracted in the diagonal direction showed high variation in mechanical properties, when compared with the respective results at the other two investigated directions, independently from the thickness of the specimens as well as from heat treatment condition. The smaller thickness specimens presented lower elongation at fracture values and for all investigated sheet directions, since they undergo plane stress conditions. Analysis of work hardening behavior showed that Bauschinger effect, which was not observed in T3 condition, became increasingly more prominent with artificial ageing time in all directions investigated.
Thermal shape morphing of membrane-type electronics based on plastic-elastomer frameworks for 3D electronics with various Gaussian curvatures (2023)

This study demonstrates a means of shape morphing planar membrane-type electronic devices into three-dimensional (3D) structures with various Gaussian curvatures using a plastic-elastomer supportive framework consisting of acrylonitrile–butadienestyrene (ABS) lines with tensile stress inside an Ecoflex film. The plastic part, created by extrusion shear printing (ESP), provides the driving force for shape morphing upon thermal annealing, whereas the elastomer part provides a base to mount membrane-type electronic devices and allows a comparably large degree of deformation. To ensure reliable interfacial adhesion in the plastic-elastomer framework, the ABS lines are treated with an allyl-terminated self-assembled monolayer (SAM) for chemical bonding to the Ecoflex layer. To determine control parameters for reliable shape morphing, the annealing conditions (e.g., temperature and time), the printing conditions (e.g., shear rate and pitch), and relative thicknesses of the ABS/Ecoflex are examined. Based on these findings, various 3D structures, including bent, cone, saddle, and dome shapes, can be generated from planar forms using ABS-Ecoflex frameworks, which are also predicted by a mechanical finite element method (FEM) simulation. Furthermore, a metal electrode and a membrane-type indium gallium zinc oxide (IGZO) transistor array are successfully mounted on ABS-Ecoflex frameworks and transformed into curvilinear structures without electrical failure.
Use of Time‐Domain Induced Polarization for Lithology Identification: A Case Study from the Hanford 300‐Area (2011)

Use of the induced polarization (IP) method, as being applied to determine the hydro stratigraphic framework at the Hanford 300‐Area, Washington, offers advantages over electrical resistivity (ER) in yielding information about the physicochemical characteristics of the subsurface. The IP response in soils results from surface polarization that is largely determined by lithology. For non‐metallic soils, IP typically shows a weak dependence on fluid conductivity, but strong near‐linear relationships to textural parameters (surface area, grain size, etc.). Compared to the ER method, IP has smaller signal‐to‐noise ratio, requiring additional care during data acquisition and processing. In particular, appropriate data weight needs to be considered for successful inversion of IP datasets.
ChemInform Abstract: A Three‐Component Coupling Approach to Cyclopentanoids. (2002)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Gene Delivery to the Airway (1999)

This unit describes generation of and gene transfer to several commonly used airway models. Isolation and transduction of primary airway epithelial cells are first described. Next, the preparation of polarized airway epithelial monolayers is outlined. Transduction of these polarized cells is also described. Methods are presented for generation of human bronchial xenografts as well as both ex vivo and in vivo gene transfer to these xenografts. Finally, a method for in vivo gene delivery to the lungs of rodents is included. Methods for evaluating transgene expression are given in the support protocols.
Multifunctional electroelastomer roll actuators and their application for biomimetic walking robots (2003)

Dielectric elastomer artificial muscles (electroelastomers) have been shown to exhibit excellent performance in a variety of actuator configurations. By rolling highly prestrained electroelastomer films onto a central compression spring, we have demonstrated multifunctional electroelastomer rolls (MERs) that combine load bearing, actuation, and sensing functions. The rolls are compact, have a potentially high electroelastomer-to-structure weight ratio, and can be configured to actuate in several ways including axial extension and bending, and as multiple degree-of-freedom (DOF) actuators that combine both extension and bending. 1-DOF, 2-DOF, and 3-DOF MERs have all been demonstrated through suitable electrode patterning on a single monolithic substrate. The bending MER actuators can act as leg and knee joints to produce biomimetic walking that is adaptable to many environments. Results of animation and the fabrications of a robot model of a synthetic bug or animal based on the MERs are presented. A new concept for an antagonist actuator for more precise control is introduced.
Wear Characteristics of Various Diamond Tools in Cutting of Tungsten Carbide (2011)

Face cutting of tungsten carbide was conducted using two monocrystalline diamond tools and three polycrystalline diamond tools to investigate the wear characteristics in terms of the crystal structure and composition of the diamond. It was found that the wear of the monocrystalline diamond tool depends on the crystal planes that form the rake face and flank face of the cutting tool, and a cleavage fracture occurs when the cutting force acts as a shear force on the (111) crystal plane. The binderless nano-polycrystalline diamond tool exhibits excellent wear resistance beyond those of the sintered polycrystalline diamond tool and chemical vapour deposition polycrystalline diamond tool, as well as better wear resistance than the monocrystalline diamond tool.
Enhanced Scattered Light Imaging of Nanoparticles by Controlling the Polarization Distribution with Photonic Crystals (2013)

An optical microscopy with a high sensitivity and resolution is required for observing semiconductor wafers and biological cells for nanotechnology and biotechnology applications. However, it is difficult to observe samples that are small compared with the optical wavelength since the signal is swamped by background noise such as dark noise and electrical noise and other signals besides that from the sample. Furthermore, light scattered from the sample cannot be focused into a spot in the image plane due to interference of polarized light, resulting in a blurred image that has a low resolution. This study proposes a method for removing the background noise and for improving the image resolution of nanoparticles by controlling the polarization direction. This method can be used to perform optical microscopy with a high sensitivity and resolution. We verify the effectiveness of this method by performing simulations and experiments. Simulations predict that the peak intensity obtained using this method will be 3.4 times higher than that obtained using a conventional microscope and that the resolution of this technique will be 0.43 times smaller than that of conventional microscopy. Experiments show that this method with a photonic crystal utilized as a radial polarization converter is capable of detecting 23-nm-diameter PSLs on a silicon wafer.
Learning to Quantify Emphysema Extent: What Labels Do We Need? (2019)

Accurate assessment of pulmonary emphysema is crucial to assess disease severity and subtype, to monitor disease progression, and to predict lung cancer risk. However, visual assessment is time-consuming and subject to substantial inter-rater variability while standard densitometry approaches to quantify emphysema remain inferior to visual scoring. We explore if machine learning methods that learn from a large dataset of visually assessed CT scans can provide accurate estimates of emphysema extent and if methods that learn from emphysema extent scoring can outperform algorithms that learn only from emphysema presence scoring. Four Multiple Instance Learning classifiers, trained on emphysema presence labels, and five Learning with Label Proportions classifiers, trained on emphysema extent labels, are compared. Performance is evaluated on 600 low-dose CT scans from the Danish Lung Cancer Screening Trial and we find that learning from emphysema presence labels, which are much easier to obtain, gives equally good performance to learning from emphysema extent labels. The best performing Multiple Instance Learning and Learning with Label Proportions classifiers, achieve intra-class correlation coefficients around 0.90 and average overall agreement with raters of 78% and 79% compared to an inter-rater agreement of 83%.
Gilbert-Varshamov bound for Euclidean space codes over distance-uniform signal sets (2002)

In this correspondence, in an extension of Piret's bound for codes over phase-shift keying (PSK) signal sets, we investigate the application of the Gilbert-Varshamov (GV) bound to a variety of distance-uniform (DU) signal sets in Euclidean space. It is shown that four-dimensional signal sets matched to binary tetrahedral, binary octahedral, and binary icosahedral groups lead to better bounds compared to the bounds for signal sets matched to dicyclic groups with the same number of signal points and comparable symmetric PSK signal sets.
Multilocus Sequence Typing of Streptococcus pneumoniae by Use of Mass Spectrometry (2011)

Multilocus sequence typing (MLST) is an important tool for the global surveillance of bacterial pathogens that is performed by comparing the sequences of designated housekeeping genes. We developed and tested a novel mass spectrometry-based method for MLST of Streptococcus pneumoniae. PCR amplicons were subjected to in vitro transcription and base-specific cleavage, followed by analysis of the resultant fragments by using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Comparison of the cleavage fragment peak patterns to a reference sequence set permitted automated identification of alleles. Validation experiments using 29 isolates of S. pneumoniae revealed that the results of MALDI-TOF MS MLST matched those obtained by traditional sequence-based MLST for 99% of alleles and that the MALDI-TOF MS method accurately identified two single-nucleotide variations. The MADLI-TOF MS method was then used for MLST analysis of 43 S. pneumoniae isolates from Papua New Guinean children. The majority of the isolates present in this population were not clonal and contained seven new alleles and 30 previously unreported sequence types.