gebhart/patrepeval huggingface dataset:
Revisiting Markovnikov Addition to Alkenes via Molecular Electrostatic Potential (2001)

Molecular electrostatic potentials (MESP) surrounding the pi-region of several substituted ethylenes (CH(2)CHR) have been characterized by locating the most negative-valued point (V(min)) in that region. The substituents have been classified as electron donating and withdrawing on the basis of the increase or decrease in the negative character of V(min) in these systems as compared to ethylene. The values of V(min) show a good linear correlation with the Hammett sigma(p) constants, suggesting that the substituent electronic effects in substituted ethylenes and substituted benzenes are basically similar. With electron-donating substituents, the position of MESP minimum is closer to the unsubstituted carbon facilitating the pi-complex formation of it with HCl at this site. Such a regiospecific pi-complex formation is found to favor the formation of Markovnikov-type transition state for the addition of HCl to CH(2)CHR. For the electron-withdrawing substituents, the V(min) location is almost equidistant and farther from the ethylenic carbon atoms. This and the less negative V(min) values account for the less regiospecific CH(2)CHR...HCl pi-complexes as well as the transition states for the HCl addition to CH(2)CHR when R is an electron-withdrawing group. The interaction energy (E(int)) between CH(2)CHR and HCl for the formation of the CH(2)CHR...HCl pi-complex shows a good linear correlation with the corresponding V(min) value.
General Active Position Detectors Protect VANET Security (2011)

Vehicle position is one of the most valuable pieces of information in a Vehicular Ad-hoc Network (VANET). The main contribution of this work is a novel approach to enhancing position security in VANETs. We propose a general active detection architecture including two components: eye-devices and ear-devices. Eye-devices include radar, infrared, camera, etc. Ear-device is the wireless transceiver. We achieve local security by enlisting the help of several on-board eye-devices to detect neighboring vehicles and to confirm their announced position coordinates heard by ear-device. We apply cosine similarity to these data to reach an agreed-location. Our solution is predicated on the widely accepted assumption that the vast majorities of vehicles are honest and behave responsively.
Catalytic fast pyrolysis of wood and alcohol mixtures in a fluidized bed reactor (2011)

Catalytic fast pyrolysis (CFP) of pine wood, alcohols (methanol, 1-propanol, 1-butanol and 2-butanol) and their mixtures with ZSM-5 catalyst were conducted in a bubbling fluidized bed reactor. The effects of temperature and weight hourly space velocity (WHSV) on the product carbon yields and selectivities of CFP of pure pine wood and methanol were investigated. A maximum carbon yield of petrochemicals (aromatics + C2–C4olefins + C5 compounds) from pine wood of 23.7% was obtained at a temperature of 600 °C and WHSV of 0.35 h−1. A maximum petrochemical yield from methanol of 80.7% was obtained at a temperature of 400 °C and WHSV of 0.35 h−1. Thus, the optimal conditions for conversion of pine wood and methanol are different. The CFP of pine wood and methanol mixtures was conducted at 450 °C and 500 °C. The hydrogen to carbon effective (H/Ceff) ratio of the feed was adjusted by changing the relative amount of methanol and wood. The petrochemical yield was a function of the H/Ceff ratio and more petrochemicals are produced from biomass when methanol is added to the CFP process. Co-feeding of 12C pine wood and 13C methanol was carried out at 450 °C. The isotopic study showed that all the hydrocarbon products contained mixtures of 12C and 13C, indicating that the carbon is mixed within the zeolite. However, the distribution of carbon was skewed depending on the product. The toluene, xylene, propylene and butenes contained more 13C. The naphthalene and ethylene contain more 12C. Wood was also co-processed with 1-propanol, 1-butanol, and 2-butanol, which showed a similar effect as methanol with an increasing petrochemical yield with an increasing H/Ceff ratio of the feed. This paper demonstrates that CFP can selectively produce a mixture of compounds where the overall yield is a function of the H/Ceff ratio of the feed.
Design and calibration of an electrostatic energy analyzer-time-of-flight mass spectrometer for measurement of laser-desorbed ion kinetic energies (1995)

The design of a hybrid electrostatic energy analyzer-time-of-flight mass spectrometer for measurement of ion kinetic energies produced by laser desorption ionization is presented. The need for experimental evaluation of the calibration and performance of the instrument is discussed and a novel laser multiphoton ionization technique, which allows experimental calibration of the energy bandpass of the electrostatic energy analyzer, is described. Laser multiphoton ionization at varying electric field strengths also allows the effects of electric field distortions on energy resolution of the instrument to be probed. Measurement of the translational energies of ions produced by 266-nm laser desorption ionization at 48 mJ/cm2 of material adsorbed to a stainless steel probe by using this instrument also is presented. Ion translational energies of +19±5, +10±5, and +10±5 eV are found for adsorbed Na+, K+, and m-xylene M+, respectively.
Ionization energy reductions in small 2,5‐dihydroxybenzoic acid–proline clusters (2002)

The photoionization of (pro)(n)DHB (pro = proline, DHB = 2,5-dihydroxybenzoic acid, n = 0, 1, 2 or 4) clusters was studied both experimentally and computationally. Experimentally the (pro)(n)DHB clusters are generated in the gas phase by laser desorption and supersonic jet entrainment. The photoionization thresholds are then determined by the mass-selective measurement of both one- and two-color photoionization efficiency curves. These experiments demonstrate that the ionization energies (IEs) of the (pro)(n)DHB clusters are substantially reduced in comparison with the IE of free DHB. Computational studies of the (pro)(n)DHB clusters provide insights into the mechanism of IE reduction. For the (pro)DHB system the IE reduction results from spin delocalization in the ion state of the cluster. In contrast, for the (pro)(2)DHB and (pro)(4)DHB clusters the IE reduction results from an inductive delocalization of electron density from pro to DHB in the ground state of the cluster. This latter effect, which is a result of the specific hydrogen-bonding interactions occurring in the mixed clusters, leads to IE reductions of >1 eV. Finally, determination of the energetics of the (pro)(2)DHB radical cation demonstrate that the DHB-to-proline proton transfer reaction is a barrierless, exoergic process in the ion state and that energetic demands for cluster dissociation to protonated (pro)(2) plus a deprotonated DHB radical are substantially lower than those for cluster dissociation to (pro)(2) plus DHB(+*). Cumulatively, these studies provide new energetic and mechanistic insights into both primary and secondary MALDI ionization processes.
Fast handoff scheme based on mobility prediction in public wireless LAN systems (2004)

Recently, wireless LAN systems have been widely deployed for public mobile Internet services. Public wireless LAN systems can provide high speed Internet connectivity using portable devices such as laptop computers, personal digital assistants (PDAs), etc. In public wireless LAN systems, reliable user authentication and mobility support are essential issues. However, re-authentication during handoff procedures causes long handoff latency and this affects the quality of service in real-time multimedia applications. A fast handoff scheme based on mobility prediction is proposed. In this scheme, a mobile host entering the area covered by an access point (AP) performs authentication procedures for multiple APs, rather than just the current AP. These multiple APs are selected by a prediction method called the frequent handoff region (FHR) selection algorithm, which takes into account users' mobility patterns, service classes, etc. Since a mobile host is registered and authenticated for an FHR in advance, handoff latency resulting from re-authentication can be significantly reduced. Simulation results show that the proposed scheme is more efficient than other schemes in terms of handoff delay and buffer requirements.
Spectroscopic Determination of Electron and Hole Effective Masses in a Nanocrystalline Semiconductor Film (1996)

Spectroelectrochemical techniques may be used to determine the absolute energy of the valence and conduction band edges of a transparent nanocrystalline semiconductor electrode. Such determinations have been made for ZnO (wurtzite) and TiO2 (anatase) electrodes constituted from nanocrystallites possessing average radii close to, and substantially larger than, the radius of a bound exciton in the corresponding bulk semiconductor. Electrodes constituted from crystallites whose radii are close to that of a bound exciton exhibit an onset for band gap absorption that is significantly blue-shifted. Those constituted from crystallites whose radii are substantially larger than that of a bound exciton exhibit an absorption onset characteristic of the bulk material. Knowing the absolute energies of band edges, the observed increase in band gap energy for electrodes constituted from confined nanocrystallites may be partitioned between the conduction and valence bands. A subsequent analysis permits determination of the effective electron and hole mass in a nanocrystalline film. Most notably, it has proved possible to determine, for the first time, a value for the effective hole mass in TiO2 (anatase) of (0.8 ± 0.2)me.
Microscopic and elemental analysis of deposits on extended wear soft contact lenses. (1986)

Les auteurs ont examine 30 lentilles avec depots nodulaires multiples en microscopie optique, microscopie electronique a balayage et par analyse elementaire. Les resultats ont montre que les lipides et le calcium sont les constituants majeurs de ce type nodulaire de depots sur les lentilles souples
The performance of a piezoelectric-sensor-based SHM system under a combined cryogenic temperature and vibration environment (2008)

A series of tests have been conducted to determine the survivability and functionality of a piezoelectric-sensor-based active structural health monitoring (SHM) SMART Tape system under the operating conditions of typical liquid rocket engines such as cryogenic temperature and vibration loads. The performance of different piezoelectric sensors and a low temperature adhesive under cryogenic temperature was first investigated. The active SHM system for liquid rocket engines was exposed to flight vibration and shock environments on a simulated large booster LOX-H2 engine propellant duct conditioned to cryogenic temperatures to evaluate the physical robustness of the built-in sensor network as well as operational survivability and functionality. Test results demonstrated that the developed SMART Tape system can withstand operational levels of vibration and shock energy on a representative rocket engine duct assembly, and is functional under the combined cryogenic temperature and vibration environment.
Adaptive Visual Servoing Controller with Feedforward Compensator without Knowledge of True Jacobian. (1996)

This paper describes an adaptive visual servoing controller consisting of an on-line estimator and a feedback/feedforward controller for uncalibrated camera-manipulator systems. The estimator does not need a priori knowledge on the kinematic structure nor parameters of the camera-manipulator system, such as camera and link parameters. The controller consists of feedforward and feedback terms to make the image features converge to the desired trajectories, by using the estimated results. Some experimental results demonstrate the validity of the proposed estimator and controller.
Novel polydiacetylenes for optical materials: beyond the conventional polydiacetylenes (2000)

Polydiacetylenes (PDAs) are of great interest due to their π-conjugated backbone related properties, such as linear and nonlinear optical properties. As a consequence, design and preparation of PDAs assume enormous importance today. This review deals with one aspect of PDA, that is, design and preparation of the diacetylene monomers and their polymers, PDAs having conjugated side groups. The aim of such an investigation is to produce materials which exhibit large third-order nonlinear optical susceptibilities and which consequently, can be obtained in a form to be customised for optical devices.
Control of the supercurrent in a mesoscopic four-terminal Josephson junction (2000)

We study the control of the supercurrent in a mesoscopic four-terminal superconductor--normal-metal--superconductor (SNS) junction, in which the N region is a quantum dot connected via tunneling barriers to two superconducting electrodes and two normal electrodes, respectively. By using the nonequilibrium Green's function method, the current flowing into the quantum dot from each electrode is derived. We find that the supercurrent between two superconducting electrodes can be suppressed and even reversed by changing the dc voltage applied across the two normal terminals, similar to recent experiments of diffusive SNS junctions and previous theories for both the ballistic and diffusive SNS junctions. Then we investigate a three-terminal SNS junction, reduced from the four-terminal junction by decoupling the dot from one normal terminal. We find that even at zero bias of the normal terminal, the supercurrent still can be controlled by changing the coupling strength between the dot and the normal terminal. In addition, both the Andreev reflection current and Andreev quasibound states depend on the phase difference of two superconductors and the coupling strength between the dot and superconducting electrodes. Finally, the behavior of the supercurrent is discussed in the limit when the normal terminals are decoupled from the system.
NMR spectroscopy in drug development and analysis (1999)

Regulatory remarks on drug analysis (in international pharmacopeiae) analysis of drugs pH-dependent NMR measurements complexation of drugs with small molecules determination of the isomeric composition of drugs NMR of body fluids solid-state NMR in drug analysis complexation of drug with large molecules NMR imaging concluding remarks.
Stimulation of EBV-activated human B cells by monocytes and monocyte products. Role of IFN- <i>beta</i>  2/B cell stimulatory factor 2/IL-6. (1988)

EBV infects human B lymphocytes and induces them to proliferate, to produce Ig, and to give rise to immortal cell lines. Although the mechanisms of B cell activation by EBV are largely unknown, the continuous proliferation of EBV-immortalized B cells is dependent, at least in part, upon autocrine growth factors produced by the same EBV-infected B cells. In the present studies we have examined the influence of monocytes on B cell activation by EBV and found that unlike peripheral blood T cells and B cells, monocytes enhance by as much as 30- to 50-fold virus-induced B cell proliferation and Ig production. Upon activation with LPS, monocytes secrete a growth factor activity that promotes both proliferation and Ig secretion in EBV-infected B cells and thus reproduces the effects of monocytes in these cultures. Unlike a number of other factors, rIFN-beta 2/B cell stimulatory factor 2 (BSF-2)/IL-6 stimulates the growth of human B cells activated by EBV in a manner similar to that induced by activated monocyte supernatants. In addition, an antiserum to IFN-beta that recognizes both IFN-beta 1 and IFN-beta 2 completely neutralizes the B cell growth factor activity of activated monocyte supernatants. These findings demonstrate that IFN-beta 2/BSF-2/IL-6 is a growth factor for human B cells activated by EBV and suggest that this molecule is responsible for B cell growth stimulation induced by activated monocyte supernatants. We have examined the possibility that IFN-beta 2/BSF-2/IL-6 might also be responsible for B cell growth stimulation by supernatants of EBV-immortalized B cells and thus may function as an autocrine growth factor. However, IFN-beta 2/BSF-2/IL-6 is not detectable in supernatants of EBV-immortalized B cells by immunoprecipitation. Also, an antiserum to IFN-beta that neutralizes IFN-beta 2/BSF-2/IL-6 fails to neutralize autocrine growth factor activity. This suggests that autocrine growth factors produced by EBV-immortalized B cells are distinct from IFN-beta 2/BSF-2/IL-6. Thus, the continuous proliferation of EBV-immortalized B cells is enhanced by either autocrine or paracrine growth factors. One of the mediators with paracrine growth factor activity is IFN-beta 2/BSF-2/IL-6.
Block-oriented random access MNOS memory (1974)

MNOS storage elements have been used to realize a block-oriented all electronic secondary memory module. This nonvolatile storage unit offers 10-microsecond data access and reliable error free operation. BORAM modules provide an immediately available cost effective alternative to electromechanical storage in severe environment applications. The text below describes an 18-million-bit advanced development model of a BORAM module and briefly outlines the growth potential of MNOS BORAM systems.
Chemically‐Specific Probes for the Atomic Force Microscope (1996)

Abstract The atomic force microscope (AFM) measures force and displacement with high sensitivity and submillisecond temporal resolution. By functionalizing the AFM probe with specific chemical groups or macromolecules it is possible to characterize the chemical and physical properties of single molecules on the nanometer scale. In this paper we discuss the key issues that must be addressed when designing and characterizing a successful immobilization chemistry, and describe the chemistry we developed to covalently immobilize oligonucleotides in a specific orientation.
Maternal cocaine use during breastfeeding. (2012)

Given the substantial benefits of breastfeeding for infant health and development, there is no reason for mothers who previously abused cocaine to avoid breastfeeding. It is important for the health care team to counsel patients both on the serious potential risks of cocaine exposure for babies and on the benefits of breastfeeding, to allow for an informed choice. Additionally, attempts should be made to estimate maternal commitment to breastfeeding and discontinuation of cocaine use, and to offer addiction counseling to mitigate the potential risks of infant cocaine exposure. It is paramount to minimize the risk to the infant, which would certainly include mothers ceasing use of cocaine while breastfeeding. For mothers who elect to breastfeed and use cocaine intermittently, breastfeeding should be delayed sufficiently after cocaine use to allow for drug elimination (approximately 24 hours).
Mouse testis cell sorting according to DNA and mitochondrial changes during spermatogenesis (1995)

Flow cytometry can measure variations in DNA content and chromatin structure as well as dramatic changes in the mitochondria of germ cells during maturation from spermatogonia to elongated spermatids. Using 10-N nonyl acridine orange (NAO), an inner mitochondrial membrane dye, it is easy to follow mitochondria rearrangements. Mouse testis cells stained with the DNA fluorescent probe propidium iodide (PI) and analyzed by flow cytometry can be discriminated on the basis of their ploidy levels into five main regions corresponding to elongated spermatids, round spermatids, diploid, S-phase, and tetraploid cells. The simultaneous use of PI and NAO demonstrated the presence of cells having low and high mitochondrial content in the haploid, diploid, and tetraploid compartments. Eleven sorting windows were selected from the bivariate analysis (PI/NAO) and the corresponding cells were identified by microscopic observation. Cells were also discriminated by two parameter analysis of DNA content vs. cell diameter. The definition of seven different regions allowed us to determine NAO or rhodamine 123 (Rh 123) uptakes in each compartment. We observed that the ratio (Rh 123/NAO) dramatically changed according to the progression of cell differentiation which occurs during spermatogenesis.
Impact of essential oils on growth rate, zearalenone and deoxynivalenol production by Fusarium graminearum under different temperature and water activity conditions in maize grain (2004)

It is apparent that essential oils should be considered as alternative preharvest natural fungicides. Further investigation on natural maize grain might be useful to study the effectiveness of these essential oils in the presence of natural mycoflora of maize grain.
Immunolocalization of integrins in the human retina. (1994)

Nine integrin subunits have been found to have unique distributions in adult human retina. An understanding of the distribution in normal retina can serve as a useful contrast to patterns of staining associated with retinal diseases.
OBSERVATION AND MODELLING OF FLUID TRANSPORT INTO POROUS PAPER COATING STRUCTURES (2002)

In paper printing, one of the most important aspects for consideration is the control of ink setting rate. Ink setting, depending on ink and press type, is a function of evaporation, curing and removal of the liquid phase by capillary mechanisms steered by the porous substrate. In most cases, absorption by the substrate is the dominating mechanism. Many paper or board substrates are coated with a layer of pigment panicles and binders. It is recognised that the void network between these panicles has the most important influence on the absorption dynamics. Many aspects of liquid absorption into porous networks are poorly understood. It is shown that it is necessary to characterise both the pore-level structure and the permeability of the network simultaneously. To remove indeterminate effects caused by the usually uneven thin layers of coatings adopted in practice, a novel methodology was developed in this work comprising of a range of unique techniques such as the formation of porous tablet-like blocks of CaC03. By applying variable compression forces to a compact of line-ground mineral, a wide range of usable porosities were obtained whilst keeping the surface chemistry and skeletal-defined pore geometry constant. The samples were characterised using mercury porosimetry. The methodology included techniques to study interactions of the structures with industrially and environmentally relevant liquids. An Ink-Surface Interaction Tester (ISIT) was used to analyse ink setting behaviour as a dynamic measure of ink rheology and solids content. This device was modified to provide a measure of the time-dependent extensional strain that is applied to the ink layer in addition to the normally obtained ink tack force values. The importance of the inertial flow regime beyond that of pure viscous flow and its impact in an interconnected network structure, where liquid does not imbibe continuously in a steady laminar flow behaviour at the wetting front, are demonstrated. Mechanisms are proposed which account for the uneven wetting line and its action in leaving parts of the pore network unfilled. Along with other findings, deviations from Lucas-Washburn (LW) scaling are elucidated. These findings are discussed in the context of paper printing and give direction for developing beyond the current limits encountered using environmentally friendly minerals and ink constituents.