Miracle-dz/UniFAR-FTUs huggingface dataset:
GaAs photocathode cleaning by atomic hydrogen from a plasma source

A clean GaAs surface is required in order to fabricate negative-electron-affinity photocathodes. Surface preparation is routinely performed by chemical cleaning and heating in ultra-high vacuum. These processes could damage the surface and produce photocathodes with low quantum efficiencies. Here an alternative technique which overcomes these problems, namely chemical cleaning and heating in ultra-high vacuum, is used. A helical resonator discharge produces hydrogen plasma which is used in a down-flow configuration to clean the GaAs(100) surface of a bulk crystal and strained layer GaAs prior to activation to negative electron affinity. Atomic hydrogen reacts with the oxides and hydrocarbons on the surface, forming volatile compounds. The photocathodes are prepared by depositing caesium onto the clean semiconductor surface. The photoemission current increases with surface cleaning. The reflection high-energy electron-diffraction pattern after atomic hydrogen cleaning reveals a clean 2×4 reconstructed GaAs(100) surface compared with a halo before cleaning.
Vegetation development on upland and marginal land treated with herbicide, for bracken (Pteridium aquilinum) control, in Great Britain

A chronosequence, or space-for-time substitution, survey was carried out to investigate the impact on associated vegetation of spraying with asulam for the control of Pteridium aquilinum. The survey covered 117 sites in upland and marginal areas of Great Britain. A series of environmental variables were measured including those defining or relating to regional spread, mesoclimate, microclimate and site condition. The vegetation showed high β-diversity with a considerable number of sites representative of upland grassland, heath and woodland. Species α-diversity increased after spraying. However regional differences were found. Indirect gradient analysis (unconstrained ordination using detrended correspondence analysis) suggested strong spatial, slope and sea distance gradients in determining species composition. Site conditions and time since spraying were also correlated. There was a high degree of collinearity between environmental variables. A hybrid ordination (using canonical correspondence analysis) was employed to investigate further the role of time (the only constrained variable) since spraying. The ordination showed a trend of species in time-after-spraying, starting with those lost early (Oxalis acetosella) and ending with stress-tolerant species (Juncus squarrosus). This ordination also revealed a second gradient almost parallel to axis 2 spanning the dichotomy between species rich grassland and degraded or invaded heath. Though control procedures appear to be reducing bracken successfully, there are strong regional variations in vegetation development. Thus, policy changes are suggested whereby either, improved cost-effectiveness, or, more effective treatment may be available.
Rapid Chemiluminescent Determination of Enrofloxacin in Eggs and Veterinary Drugs

The present work describes the development of a simple chemiluminometric method for the determination of enrofloxacin, based on the chemical generation of . In order to achieve CL conditions, two streams containing solutions of and acidic Ce(IV) were mixed. Optima chemical conditions for the CL emission were: 12.5 mM Ce(IV) in 50 mM H2SO4 and 3.0 mM of . The present method was applied to the determination of this antibacterial agent in commercial preparation, with excellent recovery, as the analysis is free from interference from common excipients in the formulation. This antibacterial is not an authorized veterinary drug for use in animals from which eggs are produced for human consumption. This method can be very useful for illegal use testing. It is capable of confirming the presence of this quinolone for concentrations above 125 ng/g. When applied to egg, it is necessary to extract the residues by acidic aqueous solution followed by centrifugation and evaporation to dryness.
Innovation in acid pickling treatments of copper by characterizations of a new series of Schiff bases as corrosion inhibitors

Purpose – Aims to investigate the inhibitive effect of the new series of Schiff base molecules, namely, N, N′‐ethylen‐bis(salicylidenimine) [S1], N, N′‐isopropylen‐bis(salicylidenimine) [S2] and N, N′‐Ortho‐phenylen acetyl acetone imine, (2‐hydroxy Benzophenone imine) [S3] on corrosion of copper during acid pickling treatment in 1 M HCl solution. Effects of concentration and temperature on the inhibition efficiencies of the selected Schiff bases have been studied systematically.Design/methodology/approach – All inhibition experiments were conducted on copper sample in 1 M HCl solution. Weight loss measurements were carried out according to the ASTM standard procedure. Polarization curves and impedance spectra were carried out in a three‐electrode cell assembly connected to an EG&G potentiostat M273 and frequency response analyzer M1025.Findings – Results obtained revealed that the studied Schiff bases act predominantly as cathodic inhibitors. The variations in inhibition efficiencies mainly depend on the .
Magnetic Nanoparticles Grafted with Cyclodextrin for Hydrophobic Drug Delivery

A novel magnetic nanocarrier, cyclodextrin (CD)-citrate-gum arabic modified magnetic nanoparticles (GAMNPs), for hydrophobic drug delivery was fabricated by grafting the citrate-modified CD onto the GAMNPs via carbodiimide activation. The analyses of the transmission electron microscopy and the dynamic light scattering revealed that the product had a mean diameter of 14.6 nm and a mean hydrodynamic diameter of 26.2 nm. The CD grafting was confirmed by Fourier transform infrared spectroscopy, and the amount of CD grafted on the GAMNPs was determined to be 28.7 mg/g by the thermogravimetric analysis. The feasibility of using CD-citrate-GAMNPs as a carrier for hydrophobic drug delivery was demonstrated by investigating the formation of the inclusion complex and the in vitro release profile using ketoprofen as a model hydrophobic drug. It was found that CD-citrate-GAMNPs exhibited a considerable adsorption capability for ketoprofen as compared to GAMNPs. The complexation of CD-citrate-GAMNPs with ketoprofen was found to be exothermic and follow the Langmuir adsorption isotherm. Also, the presence of surfactant (sodium dodecyl sulfate, SDS) led to a decrease in the inclusion of ketoprofen because the linear structure of SDS made it easier to enter the cavity of CD as compared with the less linear ketoprofen. The results of the ketoprofen inclusion and the release experiments indicate that this system seems to be a very promising vehicle for the administration of hydrophobic drugs.
Principles of Soil and Plant Water Relations

Introducing a new hobby for other people may inspire them to join with you. Reading, as one of mutual hobby, is considered as the very easy hobby to do. But, many people are not interested in this hobby. Why? Boring is the reason of why. However, this feel actually can deal with the book and time of you reading. Yeah, one that we will refer to break the boredom in reading is choosing principles of soil and plant water relations as the reading material.
Gold Nanoparticle Modified Electrodes Show a Reduced Interference by Cu(II) in the Detection of As(III) Using Anodic Stripping Voltammetry

Interference by Cu(II) causes serious problems in the detection of As(III) using anodic stripping voltammetry at gold electrodes. The behavior of Cu(II) and As(III) were examined at both a gold macro electrode and two kinds of gold nanoparticle modified electrodes, one where gold particles are deposited on glassy carbon (GC) and the other where basal plane pyrolytic graphite (BPPG) is the substrate. The sensitivity of As(III) detection was higher on gold nanoparticle modified electrodes than those on a macro gold electrode by up to an order of magnitude. In addition, the stripping peak of As(III) was narrower and more symmetric on a gold nanoparticle-modified GC electrode, leading to analytical data with a lower limit of detection. At a macro gold electrode, the peak currents of Cu(II) were higher than those on gold nanoparticle modified electrodes. Accordingly, through the use of gold nanoparticle modified electrodes, the effect of copper interference to the arsenic detection can be reduced.
Crystal structure of dichlorotetrakis(cyclohexylisocyanide)dioxo-μ2-oxodirhenium( V), C28H44Cl4N4O3Re2

C28H44Cl4N4O3Re2, monoclinic, P21/n (no. 14), a = 12.1765(6) Å, b = 9.8302(5) Å, c = 14.3784(7) Å, $ = 99.695(2)°, V = 1696.5 Å, Z = 2, Rgt(F) = 0.0221, wRref(F ) = 0.0642, T = 200 K.
A quick‐test procedure for soil and plant tissue nitrates using test strips and a hand‐held reflectometer

Abstract Development of a nitrate quick‐test for use by fanners or field consultants would likely encourage the use of plant tissue and soil nitrate tests as a means to improve nitrogen management. To evaluate a quick‐test method, nitrate concentrations in plant tissue and soils were measured using commercially available nitrate test strips and a hand‐held reflectometer. The results were compared with those obtained with standard laboratory methods. Test strip accuracy and precision and reflectometer precision were determined over a 10 day period using standard KNO3solutions and colored paper strips. Coefficients of variation ranged from 22.4 to 9.5 percent for the test strips and from 3.5 to 1.6 percent for the reflectometer. Quick‐test results were highly correlated with laboratory results for both plant tissue nitrate (r=0.87) and soil nitrate (r=0.98) concentrations. Results indicated that test strips provide a rapid, reasonably accurate and precise method to determine nitrate concentrations in both s.
Ozonation of activated sludge in the recycle stream

Intermittent ozonation of a part of the recycle sludge was performed two times a week for a laboratory-scale reactor at an average ozone dose of 0.019 g O3(gSSozonated)−1. Under these conditions a decrease of about 50% in sludge growth was obtained for the ozone-treated system, in comparison with the control. As a consequence less sludge had to be removed from the test reactor. Only a slight decrease in quality of effluent was noticed. A comparative cost calculation was made, based on these results, between an ozone-treated activated sludge system and a traditional activated sludge system. © 2001 Society of Chemical Industry
Performance Evaluation of the Brechtel Mfg. Humidified Tandem Differential Mobility Analyzer (BMI HTDMA) for Studying Hygroscopic Properties of Aerosol Particles

The Tandem Differential Mobility Analyzer (TDMA) technique coupled with aerosol humidification has been widely used for studying aerosol hygroscopicity. In this study, we evaluate the performance of a commercial Humidified TDMA (BMI HTDMA, Model 3002) with respect to DMA sizing, relative humidity (RH) control, and growth factor (GF) measurements. Unique features of this particular HTDMA include a diffusion-based particle humidifier, a DMA design allowing selection of particles up to 2 μm diameter at only 5600 volts, and the ability to study the complete deliquescence and efflorescence cycle. The sizing agreement between DMA 1 and 2 was within 2% over the 35 to 500 nm diameter range. The measured TDMA responses agreed well with theoretical calculations. The RH control and stability were tested at a suburban field site in Hong Kong. The system achieved RH equilibrium in less than 4 min when changing the RH set point. With indoor temperature changes of less than 1°C per hour, the RH control of the system was very stable at 90%, within 1% RH deviation, as confirmed by GF measurements on ammonium sulfate (AS) aerosols performed on separate days. The hygroscopic properties of various pure aerosols were examined and the results agreed well with model predictions. The application of the BMI HTDMA for field measurements was also demonstrated. Two modes were resolved from the GF distributions at 90% RH and variable hygroscopic growth with changing RH was observed. Copyright 2014 American Association for Aerosol Research
Non‐Ionic Homo‐ and Copolymers with H‐Donor and H‐Acceptor Units with an UCST in Water

A well-studied example of a thermoresponsive polymer is PNiPAAm, which exhibits a sharp coil-to-globule transition in water at its LCST. A study relating to the missing counterpart of LCST polymers is presented: N-acryloylglycinamide (NAGA) homopolymer and copolymers from NAGA and N-acetylacrylamide (NAcAAm) that show a sharp UCST (where the sharpness depends on the composition). The polymers were synthesized by free-radical copolymerization and the copolymerization parameters were determined by the method of Kelen-Tudos. The UCST was investigated by turbidimetry, regarding the influence of the copolymer composition, the polymer concentration and the addition of electrolytes.
NOx diesel exhaust treatment using a pulsed corona discharge: the pulse repetition rate effect

The pulsed corona offers real promise for degradation of pollutants in gas and water streams. This paper presents a study of NOx removal from diesel exhaust. Special emphasis is laid on the investigation of the dependence of the NO removal rate and efficiency on the pulse repetition rate (PRR). A nanosecond solid state power supply (45 kV, 60 ns, up to 1 kHz) was used for driving the corona reactor. A Mitsubishi 10 kW 3-cylinder diesel-generator engine with a total volume of 1300 cm3 was used as a source of exhaust gas. At an NO removal rate of 35% the NO removal efficiency was 53 g kW−1h−1 for PRR = 500 Hz and the initial NO concentration was 375 ppm. A semi-empirical expression for the corona reactor removal efficiency related both to PRR and to the residence time is presented. The removal efficiency decreases with increasing PRR at constant flow rate or constant residence time. This expression demonstrates reasonable agreement between the calculation results and the experimental data.
Quantum Chemical Studies on Energetic Azo-Bridged Azoles

Azo-bridged azole derivatives were designed and investigated in order to find comprehensive relationship between the structure and performance of nitrogen-rich energetic compounds. Density functional theory (DFT) was used to predict the optimized structures, heat of formation, and detonation properties. Introduction of the azido group greatly enhances the heat of formation of these derivatives due to the high energy contribution from the -N3 group. The crystal density was predicted by using the DREIDING force field. The nitroazoles show higher densities than amino and azido derivatives and hence better detonation performance. Thermal stability was analyzed using bond dissociation energies of C-NO2, C-NH2, and C-N3 bonds. Nucleus-independent chemical shifts (NICS) were calculated at the ring centers to find the stability via aromaticity. The sensitivity of the designed compounds were predicted on the basis of band gap between the highest occupied molecular orbital and lowest unoccupied molecular orbital. The amino derivatives were found to be more stable and less sensitive than the designed compounds.
Preparation and characterization of magnetic TiO2/ZnFe2O4 photocatalysts by a sol–gel method

A magnetic TiO2/ZnFe2O4 photocatalyst was prepared by a sol-gel method, and X-ray diffraction (XRD), magnetic and photocatalytic properties analysis were employed to characterize this photocatalyst. The XRD results show that ZnFe2O4 can prevent the transformation of titania from anatase to rutile. The magnetic properties analysis indicates that TiO2/ZnFe2O4 is of large saturation magnetization value and low coercivity. The photocatalytic experimental results show that TiO2/ZnFe2O4=3 and 4 are superior in photocatalytic reactivity to other proportions. TEM shows that TiO2/ZnFe2O4 has a fine core-shell fabric. After being used for four times during the photocatalytic reaction, the TiO2/ZnFe2O4 nanoparticles have good photocatalytic stability.
Development of nano-crosslinked polyacrylonitrile ions exchanger particles for dyes removal

AbstractPoly(acrylonitrile-co-divinylbenzene) nanoparticles, approximately 41 nm mean size, were prepared by precipitation polymerization technique in water:ethanol phase. Influence of the various polymerization parameters (e.g. temperature and time of polymerization, concentration of monomers and initiator, monomers composition, and cosolvent ratio) on the properties (e.g. size and conversion yield) of the particles have been investigated. Poly(acrylonitrile-co-divinylbenzene) nanoparticles were functionalized with amidoxime groups through chemical modification using hydroxyl amine to acquire ions exchanger characters. As a result, the particle size of the copolymer was increased from 41 up to 46 nm. The verification of the hydroximation process was obtained from thermogravimetric and infrared spectrometer analyses. The influence of various parameters, such as the concentration of hydroxyle amine, the temperature and the time of amidooximation, and the monomers composition, on the ion exchange capacity h.
APPLICATION OF OZONE FOR INACTIVATION OF ESCHERICHIA COLI 0157:H7 ON INOCULATED ALFALFA SPROUTS1

Chemical treatments to eliminate pathogens on inoculated seed sprouts have shown little success. This study investigated the effectiveness of aqueous ozone in killing Escherichia coli 0157:H7on alfalfa sprouts. Alfalfa sprouts inoculated with a five strain cocktail ofE. coli 0157:H7were immersed in water containing 21 ppm ozone for 2, 4, 8, 16, 32, 64 min at 4C. To increase availability and accessibility of ozone into sprout crevices, alternative treatments with continuous ozone sparging with and without pressurization were evaluated. Ozone treated sprouts were subjected to 12 psi hydrostatic pressure with pressurized ozone gas for 5 min to aid introduction of aqueous ozone into areas where pathogens may be hidden. Immersion of inoculated alfalfa sprouts (∼10 7 CFU/g) in water containing 21 ppm ozone reduced the population of E. coli 0157:H7 by 0.85 log 10 CFU/g after 64 min. There were no significant differences in log 10 reductions between the ozone treatments and control or between treatment times. With the exception of 2 min treatments, continuous ozone sparging resulted in reductions of 0.83 - 2.20 logo CFU/g, significantly higher (P ≤ 0.05) than reductions obtained by sparging with air (0.83 -1.29 logo CFU/g). Application of low hydrostatic pressure (12 psi) for 5 min subsequent to continuous ozone sparging for 2 to 64 min reduced E. coli 0157:H7 populations by 2 logo 10 CFU/g. Reductions resulting from pressurized ozone treatments did not differ significantly from those resulting from unpressurized ozone treatments, except at 32 min. Ozone treatments did not exhibit a visible detrimental effect on sprout quality. Further investigation is required to develop methods applying ozone for the purpose of decontaminating sprouts and reducing health risks. Ozone exhibits the potential for successful post harvest treatment of sprouts and also to replace other chemical treatments currently being used in the seed sprout industry.
Open source software: intellectual challenges to the status quo

Open source software is making a large impact on many aspects of society including the business community, the computing industry, the entertainment industry and higher education. The computer science education community has been quiet about issues of open source versus closed source and the role of open source code in the advancement of information technology. A survey of recent issues of SIGCSE Bulletin and SIGCSE conference proceedings shows little attention to the role open source software should play in computer science education. We are here to raise the question: "What are the social and ethical responsibilities of computer science faculty regarding open source software? "One set of issues concerns the use of open source software in teaching and the use of open source development models in the teaching of software development. Some basic questions that arise include "Should analysis of open source (and possible contributions to it) be the subject of class assignments? " and "Should open source software development models be taught? "A second set of issues concerns the use of open source software in support of teaching (e.g., using Linux as your standard platform). Some basic questions that arise include "Should we use open source software to support teaching? " and "Are these faculty ethically obligated to make contributions to the open source software base? "In this panel we will identify many of the parties involved in the ethical and social issues surrounding the use of open source in teaching and in the support of teaching, and we will identify the rights and responsibilities we, as faculty, have to the various parties. This panel will initiate a discussion that will identify additional parties and our further professional obligations.
X-ray Bragg-Surface Diffraction: A Tool to Study In-Plane Strain Anisotropy Due to Ion-Beam-Induced Epitaxial Crystallization in Fe+-Implanted Si(001)

In-plane strain anisotropy was clearly observed by the X-ray Bragg-surface diffraction technique in the silicon lattice surrounded by nanoparticles that were synthesized by an ion-beam-induced epitaxial recrystallization process of Fe-implanted amorphous Si layer. High resolution transmission electron microscopy images have shown the occurrence of metallic spherical and plate-like γ-FeSi 2 nanoparticles in the implanted/recrystallized region. These were found in different orientations within the sample, being responsible for the strain anisotropy detected. The striking anisotropy effect, due to mainly the plate-like nanoparticles in the recrystallized region, appears when comparing two (-6.04° and 83.96°) (002) rocking curves at Bragg-surface diffraction exact condition. Furthermore, the mappings of the (111) Bragg-surface diffraction reflections show an evident anisotropy between φ -6.04° and 83.96° mappings and also a marked broadening of the implanted sample profile as compared to that of the Si (matrix). Reciprocal space maps obtained for both perpendicular directions clearly exhibit this anisotropic effect in the q x direction, thus confirming the Bragg-surface diffraction results.
Evaluation of the nitrogen isotope-pairing method for measuring benthic denitrification: A simulation analysis

The nitrogen isotope-pairing method to measure sedimentary denitrification is evaluated by means of a general diagenetic model that describes the depth distribution of O-2, NH4+, (NO3- )-N-14, and (NO3-)-N-15, among others. The model simulations demonstrate that isotope fractionation effects during denitrification can be neglected, but that nonuniform mixing of added (NO3-)-N-15 with locally produced (NO3-)-N-14 causes underestimation of in situ rates of denitrification. Enrichment of bottom water with (NO3-)-N-15 concentrations above ambient levels not only results in enhanced rates of denitrification, but may also change in situ rates of coupled nitrification- denitrification. However, the resulting rates usually deviate
CIE94‐a new colour‐difference formula*

The Commission Internationale de I'Eclairage (CIE) has recently published a new colour-difference formula, called CIE94, for use in industrial pass/fail colour-difference work. It is based in CIELAB colour space but on the CMC(l:c) colour-difference formula. In this paper the history behind the development of the new formula is outlined, before the formula itself is described and compared with the CMC(l:c) formula. The role of future work in this area is briefly reviewed and the attitude of the Society's Colour Measurement Committee to CIE94 is outlined.