Miracle-dz/UniFAR-FTUs huggingface dataset:
Influence of electronic transport properties of polymer-fullerene blends on the performance of bulk heterojunction photovoltaic devices

The photovoltaic properties of polymer-fullerene bulk-heterojunction solar cells with light absorbers based on the conjugated polymers poly (2-methoxy-5-(3-,7-dimethyl-octyloxy)-1,4-phenylene vinylene (OC1C10-PPV) and regioregular poly(3-hexyl thiophene) (P3HT), each blended with the acceptor-type methanofullerene [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), are discussed. Although devices with both material combinations demonstrate good performance in terms of power conversion efficiency, they are very different in their electronic transport behavior. The profiling of the photocurrent in solar cells based on OC1C10-PPV shows a strong temperature dependence reflecting that the current is limited by the recombination of photogenerated charge carriers in the absorber layer. In contrast, devices with P3HT:PCBM active layers display a temperature independent photocurrent above some temperature, indicating that the transport and extraction of charge carriers are not significantly attenuated by losses, i.e., the mean drift length of photogenerated charge carriers exceeds the active layer thickness under device operating conditions. Therefore the active layer thickness could be increased resulting in high values of short-circuit current due to improved light absorption. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Communication. Liquid nitrogen cooling in microwave digestion

In an attempt to minimize the delay in opening Teflon pressure vessels following microwave acid digestion, and thus significantly reduce sample preparation time, various approaches to vessel cooling have been investigated. These include the feasibility of carrying out digestions with the pressure vessels immersed in liquid nitrogen and the use of liquid nitrogen as a pre- and post-digestion coolant. Liquid nitrogen cooling in the microwave unit was found to decrease digestion rates considerably, although the prevention of rapid and uncontrollable increases in pressure during digestion of organic material could be useful in some cases. Liquid nitrogen cooling subsequent to or between heating cycles was found to be very effective, especially where several heating, cooling and venting cycles were required. As well as enabling the vessels to be cooled rapidly and opened, it stopped any continuing increase in pressure which could otherwise cause the hot vessels to vent with potential loss of sample. Pre-digestion cooling also helped to delay the onset of rapid increases in pressure.
The OptiTopo Technique for Fast Assessment of Paper Topography — Limitations, Applications and Improvements

The printability of paper in flexography is largely dependent on the topographical characteristics of the substrate. Topography imaging instruments make it possible to obtain three-dimensional scans of paper surfaces that can be further used to calculate valuable quality parameters. The primary aim of the work described in this thesis has been to identify and isolate structural properties of the paper surface which significantly influence the ink distribution during printing and limit the subsequently attainable print quality.OptiTopo is an optical imaging technique which provides precise and fast topographic scans of both printed and unprinted paper surfaces. The potential and limitations of the technique have been evaluated. The optical requirements on the substrate for an accurate and precise topographic scan were determined. Detail-rendering was substantially improved using a custom-designed restoring filter, and a new enhanced spatial resolution range was established. A combination of further algorithm improvements made it possible also to obtain reflectance-factor-calibrated intensity images of scanned printed surfaces.Serious deficiencies affecting the quality of flexographic prints may appear in the form of local unprinted areas (UCA) in a full-tone print, generally caused by incomplete ink transfer. An algorithm detecting and quantifying local uncovered area was developed, tested and successfully integrated with the OptiTopo instrument. A UCA occurrence frequency distribution, indicating the percentage of the uncovered area at a certain topographical elevation, was calculated for different prints. The topographic characteristics of the uncovered areas clearly indicate that surface depressions are the primary cause of uncovered areas in flexographic printing.Four different predictive models based on topography thresholding were proposed and tested using two independent quality judgement criteria. These quality indices took into account both the amount and location of the predictions. A deeper understanding of the topographical features governing UCA occurrence was established with a proposed ink bridging effect. The total risk of non-ink-covered areas in flexography printing due to topographical features was estimated.The overall influence of paper topography on the flexography printability of full-tone areas was studied and its importance for the ink distribution assessed. The impacts of printing plate hardness, printing pressure, anilox cylinder volume and substrate roughness were quantified. Two typical flexography patterns were identified and their origin discussed: sub-millimetre elongated structures and millimetre-scale blotches.
Chemical Effects on Crude Oil Pipeline Pressure Problems

In the surface transportation of crude oils, high flowline pressures are encountered for a number of reasons. Basically these are a function of the rheological and depositional properties of the crude oil under the temperature-profile and shear-rate conditions developed in the system. These problems can be categorized into these areas: paraffin deposition, asphaltene deposition, thixotropic crude oil, turbulent flow transmission, and low-gravity asphaltic-based crude oils. Various laboratory and field tests are used to identify the key features of these problem crudes for identification and chemical treatment purposes.
One-step synthesis of robust nitrogen-doped carbon dots: acid-evoked fluorescence enhancement and their application in Fe3+ detection

Robust and highly fluorescent N-doped carbon dots (CDs) are obtained from a hybrid source, alginic acid and ethanediamine. During a hydrothermal process, the raw materials are propelled to form nano-sized particles; these resultant CDs possess desirable functional groups on the particle surface. We have further investigated their optical performance under various pH conditions as well as their capacity for sensing metal ions. The N-doped CDs especially exhibit remarkable acid-evoked fluorescence enhancement under acidic conditions. Finally, the as-prepared CDs are tested for their ability to detect Fe3+ in acidic pure water and urban river water media, and the fluorescence-quenching mechanism and recovery properties of the CD/Fe3+ mixture are also investigated.
Covalent organic frameworks for extremely high reversible CO2 uptake capacity: a theoretical approach

We report that the novel covalent organic frameworks (COFs) are capable of reversibly providing an extremely high uptake capacity of carbon dioxide at room temperature. These COFs are designed via the combination of ab initio calculations and force-field calculations. For this goal, we explore the adsorption sites of carbon dioxide on COFs, their porosity, as well as carbon dioxide adsorption isotherms. We identify the binding sites and energies of CO2 on COFs using ab initio calculations and obtain the carbon dioxide adsorption isotherms using grand canonical ensemble Monte Carlo calculations. Moreover, the calculated adsorption isotherms are compared with the experimental values in order to build the reference model in describing the interactions between the CO2 and the COFs and in predicting the CO2 adsorption isotherms of COFs. Finally, we design three new COFs, 2D COF-05, 3D COF-05 (ctn), and 3D COF-05 (bor), for the high capacity CO2 storage. The carbon dioxide adsorption values of the new 3D COFs are about six times larger than that of MOF-177. This suggests that 3D COFs are very promising candidates for high capacity CO2 storage.
The staff observation aggression scale-revised (SOAS-R): Erratum

Proper assessment of aggressive behavior is essential for an understanding of its causes. In 1987, Palmstierna and Wistedt [Acta Psychiatr Scand 76:657-663] introduced the Staff Observation Aggression Scale (SOAS), an instrument for monitoring the frequency, nature, and severity of aggressive incidents. In the present study, the validity of the SOAS severity scoring system was examined, and the severity scores were refined. The SOAS was used to record aggression on six closed wards of three psychiatric hospitals. The SOAS severity scores of 556 aggressive incidents were compared with severity estimates given on Visual Analogue Scales (VASs) by staff members. The original SOAS scores were found to be moderately correlated with the estimates of severity given by staff on the VAS. The SOAS severity scoring system was refined on the basis of the staff severity estimates. The revised scoring method and other refinements in the contents of the instrument led to the construction of the SOAS-R. The SOAS-R seems to be a promising tool for monitoring a wide range of (self-) destructive acts on psychiatric wards.
PROCEEDINGS OF THE 3RD INTERNATIONAL CONFERENCE ON MOLECULAR SIMULATION Analytical expressions on harmonic oscillators for variational path integrals

In this study, we derive analytical expressions for one-dimensional harmonic oscillators for variational path integrals (VPIs). A Gaussian-type trial wavefunction is adopted. Total and potential energies of the system are analytically expressed both for the continuous time and an approximate discretised VPIs. Obtained expressions are numerically verified using molecular dynamics calculations. Convergence properties regarding the projection time and the Trotter number are discussed.
EVALUATING THE ROLE OF A CaV2.2 SPLICE VARIANT IN BEHAVIORAL RESPONSES TO STRESS, NOVELTY, AND OTHER MONOAMINE-LINKED FUNCTIONS

iv BACKGROUND . 1 EVALUATING THE ROLE OF A CaV2.2 SPLICE VARIANT IN BEHAVIORAL RESPONSES TO STRESS, NOVELTY, AND OTHER MONOAMINE-LINKED FUNCTIONS . 13 INTRODUCTION . 13 EXPERIMENTAL PROCEDURES . 18 RESULTS . 30 DISCUSSION . 53 ACKNOWLEDGEMENTS . 57 REFERENCES . 58
Novel Application of Partially Positively Charged Silver Nanoparticles for Facilitated Transport in Olefin/Paraffin Separation Membranes

The interactions between BF4− ions (from the ionic liquid BMIM+BF4−) and the surfaces of silver nanoparticles caused the Ag surfaces to be partially positively charged, resulting in increased activity in silver−olefin complexation. The surface positive charge was confirmed by the increase in binding energy of the d5/2 orbital of the silver nanoparticles from 368.26 to 369.12 eV as the silver content increased. The surface positive charge and consequent enhancement in olefin complexation ability were exploited through the use of silver nanoparticles as a new type of olefin carrier for facilitated transport. As a result, membranes containing BMIM+BF4−/Ag nanoparticles demonstrated a mixed-gas selectivity of 17 for a 50/50 (vol %) propylene/propane mixture and showed stable performance for 100 h.
Synthesis of Some New Isoxazolidines by 1,3-Dipolar Cycloaddition Reaction of Nitrones and Olefins

A series of new isoxazolidines 5a-j were synthesized by 1,3-dipolar cycloaddition reaction of different nitrones with substituted olefins under reflux condition. The yields of products following recrystallization from absolute ethanol were of the order of 40%-66%. IR, NMR and mass spectroscopies were used for identification of these compounds.
Electrosynthesis and Characterization of Copper Oxalate Nanoparticles

Electrosynthesis has been proposed to preparation of copper oxalate nanoparticles in different sizes by electrolysis of copper plate as anode in sodium oxalate solution. The results showed that particle size of product could be tuned by reaction parameters such as electrolysis voltage and oxalate concentration. Detailed particle size of compound as a function of electrolysis voltage shows that increasing voltage from 8 to 20 V decreases particle size of CuC2O4. Also, particle size of produced copper oxalate at a constant voltage depended on concentration of oxalate solution. Under optimum condition the average particle size of product is about 22 nm.
Glycerol as a promoting and recyclable medium for catalyst-free synthesis of linear thioethers: new antioxidants from eugenol

We describe herein the use of glycerol as an efficient and recyclable solvent for the addition of thiols to nonactivated alkenes. The catalyst-free reactions take place easily using glycerol at room temperature or heating and the corresponding linear thioethers were obtained in good to excellent yields. The method was used to synthesize new sulfur-containing eugenols, which were tested for their antioxidant activities. The semisynthetic thio-derivatives were more effective in inhibition of induced lipid peroxidation compared to the precursor eugenol and the synthetic antioxidant butylated hydroxyanisole.
Interactions in undersaturated and supersaturated lysozyme solutions: Static and dynamic light scattering results

We have performed multiangle static and dynamic light scattering studies of lysozyme solutions at pH=4.7. The Rayleigh ratio Rθ and the collective diffusion coefficient Dc were determined as function of both protein concentration cp and salt concentration cs with two different salts. At low salt concentrations, the scattering ratio Kcp/Rθ and diffusivity increased with protein concentration above the values for a monomeric, ideal solution. With increasing salt concentration this trend was eventually reversed. The hydrodynamic interactions of lysozyme in solution, extracted from the combination of static and dynamic scattering data, decreased significantly with increasing salt concentration. These observations reflect changes in protein interactions, in response to increased salt screening, from net repulsion to net attraction. Both salts had the same qualitative effect, but the quantitative behavior did not scale with the ionic strength of the solution. This indicates the presence of salt specific effects.
RESPONSE OF BARLEY AND VETCH MIXTURE TO PHOSPHORUS FERTILIZER LEVELS UNDER RAINFED CONDITIONS AT RAS EL-HEKMA, MATROUH, EGYPT

Two field experiments were conducted at South of Ras El-Hekma (56 km east of Marsa Matrouh city) under rainfed conditions during 2005/ 2006 and 2006/ 2007 winter seasons, to show the response of pure stands of barley ( Hordeum vulgare L.), vetch ( Vicia sativa L.) and their mixture (75 % barley and 25 % vetch) to P-fertilizer levels (0, 7.5, 15 and 22.5 Kg P 2 O 5 / fad) to study the effect of cropping systems and P-fertilization on grain and straw yields, as well as, field stubble and water use efficiency. The obtained results scribed that, barley- vetch mixture (75 % barley + 25 % vetch) at different growth stages; i.e., booting, 50% heading and physiological stages, was superior to mono-cropping system of barley and vetch in fresh forage, dry matter and field stubble yields, as well as, crude protein yield in both seasons. Also, at harvesting time; i.e., full maturity stage, B-V mixture gave the highest grain and straw yields with higher total crude protein yield. Mixed cropping system was efficiently in water-use compared to pure stands of barley and vetch. The land equivalent ratio (LER) was more than one for mixed cropping system, which also, led to the highest LER in respect to dry matter yield, crude protein yield at different growth stages and harvesting at full maturity. Applying of higher P-fertilizer level; i.e., 22.5 Kg P 2 O 5 / fad gave the highest of studied traits. Economically, barley-vetch mixture with P-fertilizer level of 22.5 Kg P 2 O 5 / fad gave the highest values of gross and net returns, while, B-V mixture with application of 15 Kg P 2 O 5 / fad achieved the highest values of average rate of return (ARR). Ultimately, these results ascertained the importance of entering some of contingent forage crops, such as vetch to associate with barley in mixed-cropping system particularly, with P-fertilization, also to improve the crop/ livestock farming system, which might be contribute in sustainable development of rainfed conditions at Ras El-Hekma, Matrouh, Northwestern coast of Egypt.
Measuring conversions in dehydrogenation reactions with the aid of a Pd-Ag membrane

A useful method is introduced for the determination of H{sub 2} partial pressure in a gas mixture to estimate conversions in selective dehydrogenation reactions by applying a palladium-silver (Pd-23 wt% Ag) membrane. The membrane is connected downstream of the dehydrogenation reactor and operated at the same temperature and pressure as the reactor. In this method, the tubular membrane outlet is closed, allowing H{sub 2} to diffuse through the membrane wall until an equilibrium is established between the H{sub 2} pressure and the H{sub 2} partial pressure in a gas mixture inside and outside the membrane, respectively. Dehydrogenation conversions of methylcyclohexane to toluene in a packed-bed reactor calculated from the observed H{sub 2} pressures inside the closed membrane were very close to those obtained by gas chromatographic analysis at 593--643 K, 15 bar, and liquid hourly space velocities of 1.9--5.2 h{sup {minus}1}. Additional measurements with gas mixtures of H{sub 2}-N{sub 2} confirmed the reliability of the method.
Operating Proton Exchange Membrane Fuel Cells Without External Humidification of the Reactant Gases Fundamental Aspects

Operation of proton exchange membrane fuel cells (PEMFC) without external humidification of the reactant gases is advantageous for the PEMFC system, because it eliminates the need of a gas-humidification subsystem. The gas-humidification subsystem is a burden in the fuel cell system with respect to weight, complexity, cost, and parasitic power. A model for the operation of PEMFC with internal humidification of the gases is presented and the range of operating conditions for a PEMFC using dry H 2 /air was investigated. The model predicts that dry air, entering at the cathode, can be fully internally humidified by the water produced by the electrochemical reaction at temperatures up to 70°C. This model was experimentally verified for cell temperatures up to 60°C by long-term operation of a PEMFC with dry gases for up to 1800 h. The current densities, obtained at 0.6 V, were 20 to 40% lower than those measured when both gases were humidified. The water distribution in the cell, while operating with dry gases, was investigated by measuring the amount of product water on the anode and cathode sides. It was found that the back-diffusion of product water to the anode is the dominant process for water management in the cell over a wide range of operating conditions. The dominating water back-diffusion also allows internal humidification of the hydrogen reactant and prevents drying out of the anode.
A method for merging of ultra-small-angle X-ray scattering and smeared small-angle X-ray scattering patterns of fibers

A method for collimation correction and combination of anisotropic scattering patterns recorded in tandem experiments is proposed. It includes both an advanced two-dimensional extrapolation procedure for the center of the pattern and (compared with the `blind deconvolution' method) a more justified procedure for desmearing from an unknown broad primary beam profile. This semi-blind deconvolution rests on the availability of unsmeared data in a region of the smeared image. Materials exhibiting both ultra-small-angle X-ray scattering (USAXS) and small-angle X-ray scattering (SAXS) must be studied in both angular bands (tandem experiment), in order to collect the complete range of discrete scattering for nanostructure analysis. Merging of the patterns requires desmearing of at least the SAXS pattern from its point-spread function, i.e. the primary beam profile. The distorting effect of single-band experiments on the reconstructed nanostructure of polymer materials is demonstrated.
Kinetics of the Gas-Phase Reaction of Some Unsaturated Alcohols with the Nitrate Radical

Rate coefficients for the gas-phase reaction between nitrate radicals and the unsaturated alcohols 2-buten-1-ol (crotyl alcohol, a mixture of cis and trans), 3-methyl-2-buten-1-ol (MBO321), and 3-methyl-3-buten-1-ol (MBO331) and the alkenes 2-methyl-1-butene and 3-methyl-1-butene have been determined. The values that are found are (4.1 ± 0.4) × 10-13, (1.0 ± 0.1) × 10-12, (2.7 ± 0.2) × 10-13, (5 ± 1) × 10-13, and (1.4 ± 0.2) × 10-14 cm3 molecule-1 s-1, respectively. In addition, the rate coefficients for 2-propen-1-ol (allyl alcohol), 3-buten-2-ol, 2-methyl-3-buten-2-ol (MBO232), and 2-methyl-2-butene were redetermined. The experiments were performed using the relative rate technique. One set of experiments was carried out using a glass reactor and long-path FTIR spectroscopy. A second set of experiments was carried out with a collapsible sampling bag as the reaction chamber, employing solid-phase micro extraction (SPME) for sampling and gas chromatography/flame ionization detection for analysis of the re.
Thermal conductivity of high polymers

The thermal conductivities of linear high polymers were studied experimentally and theoretically. A theory of thermal conductivity in linear amorphous high polymers was derived based on a simple model of molecular structure. Predictions on the effects of molecular weight and molecular orientation on thermal conductivity taken from the theory agree with available experimental data. New data on the thermal conductivity of linear polyethylene and some polyethylene–wax blends are presented. Temperature dependence of the thermal conductivity in polyethylene was analyzed by the per cent crystallinity concept to obtain results which are in accord with the phonon theory of thermal conductivity in dielectric crystals.
Development of a Partial Least Squares–Based Integrated Addition Model for Predicting Mixture Toxicity

ABSTRACT Concentration addition (CA) and independent action (IA) models are often applied to estimate the mixture toxicity of similarly and dissimilarly acting chemicals, respectively. An integrated addition model (IAM), called the “integrated CA with IA based on a multiple linear regression (ICIM) model” was recently proposed for predicting additive toxicity of non-interactive mixtures regardless of whether mixture components produce similar, dissimilar, or both similar and dissimilar modes of action. In the ICIM, the effective concentrations of mixtures experimentally tested were regarded as the response variable, and the results estimated by CA and IA were considered as the predictor variable. However, it can be highlighted that the multicollinearity problem (i.e., a linear relationship between predictor variables), which may be caused in the existing ICIM model employing ordinary least squares regression. Therefore, the objectives of this study were to develop and evaluate a Partial Least Squares-based IAM (PLS-IAM) not only to overcome the multicollinearity problem, but also to combine the CA and IA into an IAM using the latent variable that accounts for most of the variation in the response. Through four test datasets, this study showed that the PLS-IAM overall outperformed the other reference models, including the CA, IA, and ICIM models.