gebhart/patrepeval huggingface dataset:
Low-complexity blind synchronization and demodulation for (ultra-)wideband multi-user ad hoc access (2006)

Synchronization is a performance-critical factor in most communication systems: from classical narrowband and emerging (ultra) wideband (UWB) point-to-point links to cooperative or ad hoc networking, where access must deal with multi-user interference (MUI) and possibly severe intersymbol interference (ISI). For universal applicability to all these scenarios, we develop a blind synchronization and demodulation scheme which relies on intermittent transmission of nonzero mean symbols. These enable MUI- and ISI-resilient timing acquisition via energy detection and low-complexity demodulation by matching to a synchronized aggregate template (SAT). The resultant SAT receiver offers distinct advantages over RAKE, has low-complexity and lends itself naturally to decision-directed enhancements. Its blind operation nicely fits the requirements of multi-user ad hoc access and its ability to handle ISI is particularly attractive for UWB communications. Analytical performance evaluation and simulations testing our novel scheme in UWB settings confirm its high potential for deployment
Plasma assisted chemical vapor deposition of diamond and applications: from large-grain polycrystalline diamond to nanocrystalline diamond (2004)

Summary form only given. Growth of diamond with extreme physical and chemical properties can be achieved in electrical discharges under properly controlled plasma chemistry at temperatures and pressures where graphite, instead of diamond, is thermodynamically stable. This discovery led us to wide open opportunities for applying the extreme hardness, thermal conductivity, optical and microwave transparency, chemical inertness, wear resistance, coefficient of thermal expansion, dielectric strength, carrier saturation velocities, and many other interesting properties of diamond crystals and coatings to industrial and scientific applications. Plasma density, plasma chemistry, as well as physical processes in plasmas such as ion bombardment of substrates and/or the growing diamond surfaces all play important roles in the nucleation and the growth of diamond on various substrates. Plasmas generated in gaseous mixtures such as methane and hydrogen with controlled dilution by argon as well as plasmas generated in vapor mixtures formed from properly mixed liquid solutions alone have been developed and optimized for the nucleation and growth of diamond of selected crystal orientations, grain sizes, and doping levels. A systematic experimental project has also been conducted to explore diamond nucleation and growth by plasmas generated in gas mixtures of methane and hydrogen that are highly diluted by more than 90% argon. Growth of well-faceted microcrystalline diamond films with preferred (100) or (111) crystal orientation as well as nanocrystalline diamond films could be tailored by controlling plasma parameters such as microwave power density, gas pressures and compositions, and substrate temperatures.
An electronic transition chemical laser (1978)

cw laser action was achieved on the 2P1/2→2P3/2 transition of the iodine atom by energy transfer from the 1Δ metastable state of O2. The excited oxygen was generated chemically by flowing chlorine gas through a basic solution of 90% H2O2. The effluent from the oxygen generator was mixed with molecular iodine at the entrance of a longitudinal flow laser cavity where the I2 was dissociated by a small amount of O2(1Σ) that was present in the flow due to energy pooling processes. The measured output power was greater than 4 mW.
Scanrom, a novel non-volatile memory cell storing 9 bits (2004)

We present a novel non-volatile memory cell based on a dual-gate transistor with an ONO charge-trapping dielectric underneath the drain-side gate. Multiple bits are stored along the width of the device. By contacting the gates from both sides and applying an appropriate bias difference to each, the individual bits are addressed for both reading and writing. We experimentally demonstrate reading and writing of 9 bits in a prototype cell and discuss to possibility of storing an even higher number of bits.
Bismuth pyrochlore thin films for dielectric energy storage (2015)

Thin films of cubic pyrochlore bismuth zinc niobate, bismuth zinc tantalate, and bismuth zinc niobate tantalate were fabricated using chemical solution deposition. This family of materials exhibited moderate relative permittivities between 55 ± 2 and 145 ± 5 for bismuth zinc tantalate and bismuth zinc niobate, respectively, and low loss tangents on the order of 0.0008 ± 0.0001. Increases in the concentration of the tantalum end member increased the dielectric breakdown strength. For example, at 10 kHz, the room temperature breakdown strength of bismuth zinc niobate was 5.1 MV/cm, while that of bismuth zinc tantalate was 6.1 MV/cm. This combination of a high breakdown strength and a moderate permittivity led to a high discharged energy storage density for all film compositions. For example, at a measurement frequency of 10 kHz, bismuth zinc niobate exhibited a maximum recoverable energy storage density of 60.8 ± 2.0 J/cm3, while bismuth zinc tantalate exhibited a recoverable energy storage density of 60.7 ± 2.0 J/cm3. Intermediate compositions of bismuth zinc niobate tantalate offered higher energy storage densities; at 10 mol. % tantalum, the maximum recoverable energy storage density was ∼66.9 ± 2.4 J/cm3.
ChemInform Abstract: SYNTHESIS OF 1,3‐DIAZEPIN‐2‐ONE NUCLEOSIDES AS TRANSITION‐STATE INHIBITORS OF CYTIDINE DEAMINASE. 2 (1981)

Abstract Aus dem Diazepinon (I) erhält man mit dem N‐Phenylselenyl‐phthalimid (II) stereoisomere Substitutionsprodukte (III), die oxidativ unter Eliminierung des Phenylselenyl‐Restes zum ungesättigten Carbinol (IV) führen.
Optical Testing with the Digital Heterodyne Interferometer (1981)

In the digital heterodyne interferometer, the single frequency output of a laser is split, and each component is frequency shifted by separate Bragg cells. The difference of the frequency shifts can be 0 Hz for conventional "see the fringe" operation, or 1 MHz for accurate phase measurement. One of these components then has its polarization rotated by 90°, and the two are combined without loss by a polarization selective beam combiner cube. The composite beam is expanded to 2 cm, and injected into a polarization selective Twyman-Green interferometer. Each arm has a quarter-wave plate oriented such that the return radiation has its polarization rotated 90°, and the two beams then exit the interferometer. Thus, at the interference plane there exists light of orthogonal polarizations with one polarization having traveled the reference path and one the test path; and the polarizations have a 1 MHz frequency difference. A linear polarizer oriented at a 45° angle to these polarizations causes the beams to mix.
Oxidized cellulose esters: I. Preparation and characterization of oxidized cellulose acetates — a new class of biodegradable polymers (2002)

Oxidized cellulose acetates (OCA), with a degree of substitution (DS) value ranging between 1.1 and 2.3 and a free carboxylic acid group content of 20% (w/w), have been prepared by reacting oxidized cellulose (OC, COOH content 20% w/w) with a mixture of acetic acid and acetic anhydride in the presence of sulfuric acid as a catalyst. The DS of OCA, in general, increased with increasing reaction temperature, reaction time, and concentration of acetic anhydride in the reaction mixture. The yield of OCA, in contrast, increased with increasing concentration of acetic anhydride and decreased with increasing reaction time and temperature. The intrinsic viscosity of OCA varied between 0.100 and 0.275, depending on the reaction conditions used during its preparation. In general, an increase in reaction temperature and the use of a prolonged reaction time decreased the intrinsic viscosity of OCA. No correlation was found between DS and intrinsic viscosity of OCA. The apparent pKa of OCA is 3.7-3.9. The new OCA polymers are practically insoluble in water and slowly dissolve in pH 7.4 phosphate buffer solution. They are, however, soluble in a range of organic solvents (e.g. ethyl acetate, acetone, acetone/water, chloroform/methylene chloride, dimethylsulfoxide, dimethylformamide, and/or chloroform/methanol).
High-accuracy alignment based on subspace decomposition (1998)

One of the most crucial emerging challenges in Lithography is achieving rapid and accurate alignment under a wide variety of conditions brought about by different overlying films occluding the marks. The problem is exacerbated by planarizing processes such as Chemical Mechanical Polishing (CMP) and asymmetric processes such as metal deposition and photoresist coating. These processes give rise to displacement of the perceived position of the alignment mark. Thus, any effective algorithm must be based on the history of such displacements. A new approach based on subspace decomposition of the alignment signals is described. The method only applies to imaging and/or scanning based alignment signals. The main assumption is that the process-induced asymmetries are small enough such that only linear effects need to be considered. We first find the subspace of alignment signals using a set of alignment signals with pre-known positions. The positions of the new signals are measured based on the fact that, if shifted correctly, they will lie in the same subspace as the previous signals. Current alignment algorithms assume symmetric alignment signals. Since this method exploits the structure of the signals, it results in more accurate measurement of the position than the current algorithms. Simulation results show that the alignment error is about an order of magnitude smaller than that achieved with conventional Maximum Likelihood or phase-fitting approaches. The computational complexity also increases linearly with the dimension of the subspace and is linearly proportional to signal bandwidth.
Rubber-Thermoplastic Compositions. Part IV. Thermoplastic Vulcanizates from Various Rubber-Plastic Combinations (1981)

Abstract The ultimate mechanical properties ( σ B and ε B ) and elastic recovery (inversely measured by tension set) of dynamically vulcanized melt mixed rubber-plastic blends increase with the similarity of the rubber and plastic in respect to the critical surface tension for melting γ c . They also increase with the crystallinity W c of the plastic (resin) phase. Stiffness, as measured by Young's modulus E , increases with the differences in surface energy between the two phases.
Development of heat transfer method for non-intrusive pressure measurement in natural gas pipelines (1994)

A method for non-intrusive measurement of internal pressures in flowing and non-flowing natural gas distribution pipelines has been developed. The method is based on temperature changes observed at various locations on the outside wall of the pipe in response to a circumferential band of heat applied to it. Because of the complex flow patterns in the pipe, the pressure-related phenomena induce second-order effects on the heat transfer to the gas or liquid in the pipeline. Experimental results from both laboratory and field measurements have been compared with predictions from TEMPEST, a computation fluid dynamics (CFD) model, to aid in understanding the flow characteristics. In this method, a 2.5-in. band or ring heater device placed around the outer circumference of the pipe is used to apply that to the outer wall of the pipe. The effect of heat input ranging from 250 to 1,000 watts has been evaluated for pipe diameters ranging from 4 in. to 12 in. The expected range of Reynolds numbers spans the laminar, transitional, and turbulent flow regimes, thus adding significant complexity to the problem. Results have shown that a heater power of about 1,000 watts for flowing gas and 250 watts for non-flowing gas enables anmore » acceptable estimate of pressures for most cases. The method can be used to effectively determine whether a pipe is filled with gas or liquid. It can also indicate whether the gas is flowing or static. For flowing gas, upstream-to-downstream and top-to-bottom temperature differences at the surface of the pipe are jointly used to determine gas flow rate and pressure. For no-flow conditions, the upstream-to-downstream temperature difference is zero, and pressures ranging from 0 to 150 psig can be differentiated solely by the temperatures along the outside wall of the pipe.« less
Magnetic alignment of Ni-coated single wall carbon nanotubes in heat transfer nanofluids (2010)

Thermal conductivity (TC) of heat transfer nanofluids containing magnetic-metal-coated carbon nanotubes can be significantly enhanced (&gt;60%) by applied magnetic field. In this paper, we report the observed real images of Ni-coated single wall carbon nanotubes in water and oils (polyalphaolefin, polyol ester) under magnetic field by high speed microscopy, and correlate them with TC measurements. Initially, the nanotubes are randomly dispersed in the fluid, however, on longer holding in magnetic field the nanotubes gradually stretch and are finally aligned. The chain length in the images is found to be around 30∼150 μm, which is much longer than the real length of individual nanotubes (5∼40 μm), indicating that nanotubes are aligned and form some chains and clusters. Because of the semicontinuous nature of Ni magnetic nanoparticles, as well as the viscosity resistance of the fluid itself, it takes some time for the Ni-coated nanotubes to respond to the applied magnetic field and align. Time dependent TC experiments indicate that alignment process dominates the TC enhancement rather than microconvection. Finally, scanning electron microscopy images also show that the Ni coated nanotubes are aligned well under the influence of a magnetic field. Transmission electron microscopy images indicate that nickel remains stable and attached onto the nanotubes after the magnetic field exposure and movements.
Improved Calibration Of Acoustic Plethysmographic Sensors (1993)

Improved method of calibration of acoustic plethysmographic sensors involves acoustic-impedance test conditions like those encountered in use. Clamped aluminum tube holds source of sound (hydrophone) inside balloon. Test and reference sensors attached to outside of balloon. Sensors used to measure blood flow, blood pressure, heart rate, breathing sounds, and other vital signs from surfaces of human bodies. Attached to torsos or limbs by straps or adhesives.
Easy approach to N-(aminoacyl)taurine derivatives (1988)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEasy approach to N-(aminoacyl)taurine derivativesMaria Altamura and Giovanni AgnesCite this: J. Org. Chem. 1988, 53, 6, 1307–1309Publication Date (Print):March 1, 1988Publication History Published online1 May 2002Published inissue 1 March 1988https://pubs.acs.org/doi/10.1021/jo00241a034https://doi.org/10.1021/jo00241a034research-articleACS PublicationsRequest reuse permissionsArticle Views261Altmetric-Citations4LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Design and Optimization of Benzimidazole-Containing Transient Receptor Potential Melastatin 8 (TRPM8) Antagonists (2010)

Transient receptor potential melastatin 8 (TRPM8) is a nonselective cation channel that is thermoresponsive to cool to cold temperatures (8-28 °C) and also may be activated by chemical agonists such as menthol and icilin. Antagonism of TRPM8 activation is currently under investigation for the treatment of painful conditions related to cold, such as cold allodynia and cold hyperalgesia. The design, synthesis, and optimization of a class of selective TRPM8 antagonists based on a benzimidazole scaffold is described, leading to the identification of compounds that exhibited potent antagonism of TRPM8 in cell-based functional assays for human, rat, and canine TRPM8 channels. Numerous compounds in the series demonstrated excellent in vivo activity in the TRPM8-selective "wet-dog shakes" (WDS) pharmacodynamic model and in the rat chronic constriction injury (CCI)-induced model of neuropathic pain. Taken together, the present results suggest that the in vivo antagonism of TRPM8 constitutes a viable new strategy for treating a variety of disorders associated with cold hypersensitivity, including certain types of neuropathic pain.
Inhibition of ruminant feed enzyme polysaccharidase activities by extracts from silages (2000)

Extracts from 14 barley silages inhibited endo-1, 4-β-xylanase and α-amylase activities of a ruminant feed enzyme additive from Trichoderma longibrachiatum by 23 to 50% but had little effect on cellulase activity. The inhibitory factor(s) were <10 kDa in size and were stable to autoclaving. These observations may explain why feed enzymes are generally less effective when applied to silages than when applied to dry feeds. Key words: Silage, fibrolytic enzymes, Trichoderma, xylanase, inhibitors
Genetically Targeted Adenovirus Vector Directed to CD40-Expressing Cells (2003)

The success of gene therapy depends on the specificity of transgene delivery by therapeutic vectors. The present study describes the use of an adenovirus (Ad) fiber replacement strategy for genetic targeting of the virus to human CD40, which is expressed by a variety of diseased tissues. The tropism of the virus was modified by the incorporation into its capsid of a protein chimera comprising structural domains of three different proteins: the Ad serotype 5 fiber, phage T4 fibritin, and the human CD40 ligand (CD40L). The tumor necrosis factor-like domain of CD40L retains its functional tertiary structure upon incorporation into this chimera and allows the virus to use CD40 as a surrogate receptor for cell entry. The ability of the modified Ad vector to infect CD40-positive dendritic cells and tumor cells with a high efficiency makes this virus a prototype of choice for the derivation of therapeutic vectors for the genetic immunization and targeted destruction of tumors.
Improving GRAPPA reconstruction using joint nonlinear kernel mapped and phase conjugated virtual coils (2019)

To improve the reconstruction condition and alleviate the noise amplification of GRAPPA reconstruction by aggregating the phase conjugated and nonlinear kernel mapped coils with the original physical coil. Nonlinear GRAPPA (NL-GRAPPA) is a kernel-based non-iterative approach which can reduce noise-induced error in GRAPPA reconstruction. And virtual conjugate coil (VCC) embeds the conjugate symmetric property of k-space into GRAPPA data synthesis to improve reconstruction condition. This work proposed NL-VCC-GRAPPA to jointly utilize the nonlinear mapped virtual coil and phase conjugated virtual coil to further reduce noise amplification in parallel imaging. In vivo static and dynamic 2D imaging accelerated by uniform undersampling schemes were performed to evaluate the proposed method in terms of visual image quality, root-mean-square-error (RMSE), and geometry factor (g-factor). The effects of acceleration factors, calibration data size and kernel shape on the proposed model were also separately analyzed and discussed. The proposed method illustrated improved visual image quality evidenced by reduced retrospective RMSE and prospective g-factor comparing with conventional GRAPPA and the recently proposed iterative SENSE-LORAKS reconstructions. Although a larger amount of calibration data and smaller kernel size were required to stabilize the calibration of fourfold extended kernel for the proposed method, it was non-iterative and relatively insensitive to parameter adjustment in the applications. The proposed NL-VCC-extension to conventional GRAPPA brings visible improvements for imaging scenarios accelerated by the widely available uniform undersampling schemes in a practically efficient manner without iteration.
Squeeze Deployed Sulfide Inhibitor Successfully Averts Challenging Sulfide Scale Deposition in Permian and Williston Unconventional Basins (2022)

Abstract Sulfide scales (zinc, lead and iron sulfide) are currently causing considerable production challenges as mature fields are kept operational, and as deeper-hotter reservoirs are being developed. An effective way to combat conventional scaling is to inject "squeeze" scale inhibitors into the formation which are then lowly released as production resumes, providing scale protection. This option has not been the case for sulfide scales due to formation kinetics and lack of suitable products. In this study we present two field cases where new generation squeezable sulfide inhibitors were deployed with clear success in inhibiting sulfide deposition and establishing stable production. Also presented are the development methods and chemical synthesis details for the development of a squeezable product. A novel fast screening technique is detailed as well as a new type of residual monitoring method for the polymeric species that inhibit the sulfide scales. In the Permian Basin, newly completed long horizontal wells in the Sprayberry Formation were on a constant rotation of work overs (every 3 to 5 days) due to severe zinc and iron sulfide deposition. Early squeezes performed with known phosphonate/ester scale inhibitors, and end-capped polymer were unsuccessful. A new generation of squeezable sulfide inhibitor was deployed and stabilized production as well as the scaling ion data. A unique and fast residual analysis methodology (using a specialized HPLC column) was developed as part of the squeezable sulfide inhibitor development project capable of providing a unique selectivity in a high TDS brine without interferences increasing residual monitoring and squeeze confidence. In the Williston basin many fields are known for their troubled history with iron sulfide. To date, the preferred option has been continuous well cleanout that impacts production, next generation squeezable sulfide inhibitor was deployed and it successfully increased productivity and eliminated well clean outs for the trialed wells. This technology summarized in the paper offers a substantial step change in the ability to protect against sulfide scale via squeeze application. These field treatments show that next generation squeezable inhibitors were successful in inhibiting sulfide scales with no observed formation damage, upset to process facilities during flow back, or decline in productivity.