Miracle-dz/UniFAR-FTUs huggingface dataset:
Sensing NO3-N and K Ions in Hydroponic Solution Using Ion-Selective Membranes

Rapid on-site sensing of nitrate-nitrogen and potassium ions in hydroponic solution would increase the efficiency of nutrient use for greenhouse crops cultivated in closed hydroponic systems while reducing the potential for environmental pollution in water and soil. Ion-selective electrodes (ISEs) are a promising approach because of their small size, rapid response, and the ability to directly measure the analyte. The capabilities of the ISEs for sensing nitrate and potassium in hydroponic solution can be affected by the presence of other ions such as calcium, magnesium, sulfate, sodium, and chloride in the solution itself. This study was conducted to investigate the applicability of two ISEs consisting of TDDA-NPOE and valinomycin-DOS PVC membranes for quantitative determinations of -N and K in hydroponic solution. Nine hydroponic solutions were prepared by diluting highly concentrated paprika hydroponic solution to provide a concentration range of 3 to 400 mg/L for -N and K. Two of the calibration curves relating membrane response and nutrient concentration provided coefficients of determination () > 0.98 and standard errors of calibration (SEC) of -N and K in paprika hydroponic solution due to almost 1:1 relationships and high coefficients of determination ( > 0.97) between the levels of -N and K obtained with the ion-selective electrodes and standard instruments. However, even though there were strong linear relationships ( > 0.94) between the -N and K concentrations determined by the Gran`s plot-based multiple standard addition method and by standard instruments, hydroponic -N concentrations measured with the ISEs, on average, were about 10% higher than those obtained with the automated analyzer whereas the K ISE predicted about 59% lower K than did the ICP spectrometer, probably due to no compensation for a difference between actual and expected concentrations of standard solutions directly prepared.
Architektura systemu wielorobotowego w oparciu o paradygmat SOA

W pracy przedstawiono nowe podejście do agenta softwarowego oraz systemów wieloagentowych oparte na paradygmacie Service Oriented Architecture. Na tej podstawie zaproponowano nowe podejście do architektury robota i systemów wielorobotowych. Te architektury mają służyć do współdziałania heterogenicznych robotów w wykonywaniu złożonych zadań. Podstawowym założeniem jest traktowanie poszczególnych możliwości robota jako indywidualnych usług, które mogą być dynamicznie komponowane, synchronizowane i wywoływane w celu realizacji złożonego zadania.
Volatile constituents of the essential oil leaf of Lantana salvifolia Jacq. (Verbenaceae)

The essential oils from the leaves of Lantana salvifolia Jacq. (Verbenaceae) growing in Brazzaville, Congo, were analysed by GC and GC-MS. They were characterized by the predominance of neral (15-20%) and geranial (26-34%); the more representative sesquiterpenes were β-caryophyllene and its oxide (11-18%). This essential oil is compared with that of Lantana camara L. and other species.
Microbial Degradation of Volatile Anthropogenic Organic Chemicals.

Abstract : Experiments were conducted to study the degradation of trichloroethylene (TCE) by bacteria able to grow on methane (methanotrophs) and to consider specific aspects relative to the ultimate design of a bioreactor to purify air streams contaminated with TCE that could originate from air stripping of contaminated aquifers. A procedure was investigated that consisted of initially sorbing TCE from the gas phase to granular activated carbon (GAC). The GAC then was treated by first extracting TCE from the GAC by using methanol and then providing the methanol containing TCE to methanotrophs. The experiments indicated that neither TCE nor methane could be significantly degraded by methanotrophs in the presence of a high but nontoxic concentration of methanol in water. A study was conducted to determine whether there is a concentration of TCE (a threshold) below which methanotrophs growing on methane would not be able to degrade TCE. TCE was degraded below a concentration of about 2 parts per trillion, and thus no threshold was found. The degradation of TCE by methanotrophs in the presence of different packing materials was assessed. The results showed that some packing materials inhibited TCE degradation unless they were first washed with an aqueous solution of ethylenediaminetetraacetic acid (EDTA).
Mild synthesis of benzylated bamboo in LiCl/DMSO solution

Benzylated bamboo was mildly synthesized in nonaqueous medium without mercerization pretreatment. The ball-milled bamboo was firstly preswelled in lithium chloride/dimethyl sulfoxide (LiCl/DMSO) solution and then reacted with benzyl chloride in the presence of solid NaOH with varying molar ratios of benzyl chloride to OH groups of bamboo (1–4), reaction times (1–8 h), and temperatures (60–90°C). Benzylated bamboo products with yields from 51.1 to 106.9% and with degrees of substitution [DS, apparent value evaluated by Fourier transform infrared (FTIR) spectra] between 0.2 and 1.2 were synthesized. FTIR and 13C cross polarization/magic angle spinning nuclear magnetic resonance (CP/MAS NMR) spectroscopy confirmed the incorporation of benzyl groups into bamboo; SEM observations of the highly benzylated bamboo showed porous surface with small irregular slices ascribed to the disruption of intermolecular and intramolecular hydrogen bonds between cellulose. Because of the degradation of amorphous components, the crystallinity decreased negligibly after modification and the thermal stability increased slightly but was lower than that of cellulose. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Understanding amyloidogenesis through computer simulations: Tackling the sampling problem by using replica exchange umbrella sampling and hydrogen bond biasing potentials

In this chapter the computer simulation methods and principles are discussed, that are the basis for the development of the advanced simulation methods in part II and III of this thesis. The subjects that are reviewed include molecular dynamics, expression of the interactions between atoms into equations, free energy calculation using umbrella sampling and replica exchange molecular dynamics. The first non-military computer became available in the 1950s, allowing the first computer simulation studies [1]. Pioneering work was performed by Metropolis in his effort to study as many different problems as possible, in order to test the logical structure and demonstrate the capability of computer simulations [1]. The work of Metropolis lead to a famous publication, together with Rosenbluth, Rosenbluth, Teller and Teller, describing the Metropolis Monte Carlo (MC) method [2]. Shortly after this paper, Fermi, Pasta and Ulam described a radically different approach in their paper on the investigation of the dynamics of an anharmonic, one-dimensional crystal [3]. Almost simultaneously, Alder and Wainwright reported the first proper molecular dynamics (MD) simulation on a cluster of hard spheres [4]. The common but erroneous assumption that continuous potentials would result in a more complicated and demanding simulation around that time [5, 6] delayed the examination of a real liquid to the mid 60s. Then Rahman performed an MD simulation of liquid argon [7], although a real crystal system was already simulated in the late 50s by Vineyard, on radiation damage of copper crystals [8]. The success of computer simulations originates from the capability to evaluate methematical equations to any desired accuracy at great speed. As the basic laws of nature are generally expressed in equations that, apart from a few very simple cases, cannot be solved analytically, systems governed by these laws are amenable to evalu-
Applicability of nitrogen‐doped ZnO single crystals for photoconductive type UV sensors

Nitrogen-doped (N-doped) ZnO single crystals were prepared by the hydrothermal method. Resistivity of the N-doped ZnO single crystal was 107–108 Ωcm, which was about 104-times higher than that of the non-doped ZnO single crystal. Photocurrent of the O-face was larger than that of the Zn-face and maximum photoresponsivity was about 4×103 A/W. Photosensitivity (light/dark current ratio) of the Zn-face of the N-doped single crystal was 4×104 under illumination of 15 µW/cm2, but that of the O-face was about 7×104. The visible rejection ratio (UV/visible photocurrent ratio) was over 104 for the Zn-face of the N-doped ZnO single crystal. Time response of the photocurrent of the N-doped ZnO single crystal was remarkably improved compared to that of the non-doped ZnO single crystal. An N-doped ZnO single crystal is useful as a material for photoconductive type UV sensors. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of Low Turbidity and Algae on UV Disinfection Performance

It is well‐recognized that changes in ultraviolet (UV) absorbance or significant concentrations of amorphous biological wastewater solids in a water matrix can affect UV disinfection performance. However, the effects of low concentrations of drinking water particulates (turbidity) and algae on UV disinfection effectiveness are more poorly understood. This article presents the results of continuing studies at the University of New Hampshire (Durham) on the effects of particles on UV disinfection. The research was conducted in two phases of medium‐pressure UV collimated beam tests. The first phase compared the dose–response of seeded MS2 bacteriophage in waters with montmorillonite clay turbidity up to 12 ntu and algal content up to 42 μg/L as chlorophyll a (~42,000 cells/mL) to the dose–response of seeded MS2 in deionized water. The second phase compared phase 1 results with the inactivation of MS2 in the presence of naturally occurring turbidity in reservoir waters. Results indicated UV light was effective for inactivating MS2 in the presence of montmorillonite clay, algae, and naturally occurring turbidity in collimated‐beam testing.
Nanolithography using wet etched silicon nitride phase masks

A new technique for performing chromeless phase shift optical nanolithography is presented. Phase masks have been wet etched into silicon nitride membranes, using either hot H3PO4 or HF. Contact exposure through these masks results in developed photoresist features as small as 90 nm, even for masks with shallow sidewall slopes. The observed effect is attributed to the presence of an abrupt phase step at some point on the wet etch profile, although this does not need to correspond to a π phase shift in order to obtain good contrast exposures. Simulations have been performed for typical wet-etching profiles, and it is found that good contrast is expected for a very wide range of etch depths. In addition, the width of the null in the near-field intensity profile varies with etch depth, indicating that control of feature size is possible. This technique is simple and inexpensive, making it an attractive candidate for nanopatterning a wide variety of substrates.
Preparation and characterization of single- and double-shelled cyhalothrin microcapsules based on the copolymer matrix of silica–N-isopropyl acrylamide–bis-acrylamide

Silica, as a controlled release material, has been applied widely in many fields owing to its high thermal and mechanical stability, corrosion resistance, biocompatibility and low cost. We herein synthesized pesticide cyhalothrin/SiO2 microcapsules and cyhalothrin/silica–N-isopropyl acrylamide (NIPAM)–bis-acrylamide (MBA) microcapsules. A silica shell was formed through the hydrolysis and polycondensation of tetraethyl orthosilicate under alkaline conditions, and then the single-shelled silica microcapsules were modified by triethoxyvinylsilane and cross-linked with NIPAM and MBA through free radical polymerization. The microcapsules were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis, and their release kinetics and biological activity were also detected. The single- and double-shelled microcapsules had excellent loading abilities for cyhalothrin (about 50.0% and 25.0%, respectively). The release curves showed that the double-shelled microcapsules allowed better controlled release, probably through a combination of diffusion and erosion. The microcapsules showed longer persistence than that of cyhalothrin emulsifiable concentrate. This study provides a novel material for fabricating pesticides with controlled release.
Structure of Aqueous Mixtures of N,N-Dimethylacetamide Studied by Infrared Spectroscopy, X-ray Diffraction, and Mass Spectrometry

Infrared (IR) spectroscopy and X-ray diffraction measurements have been performed at 298 K on mixtures of N,N-dimethylacetamide (DMA) and water over the entire range of DMA mole fractions (xDMA). Mass spectra have also been measured on the clusters that have been isolated by the adiabatic expansion of liquid droplets of the mixtures. The IR overtone band of the CO stretching vibration for the DMA−D2O mixtures and the O−D stretching band of HDO for the DMA−H2O mixtures containing 5% D2O both shifted to lower frequencies as the water content increased, accompanied by two inflection points, at xDMA = 0.1 and 0.6. These results suggested that hydrogen bonding between the CO group and the water molecules and structural changes of predominant solvent clusters were taking place at these specific mole fractions. The X-ray radial distribution functions have indicated that the structure of the predominant solvent clusters in the mixtures could be classified into four regimes: (1) 0 < xDMA ≤ 0.1, where the water cl.
NMR Spin‐Echo Trains for a Coupled Two‐Spin System

Abstract : The effect of pulse separation on NMR CarrPurcell spin echo trains is considered for pulse experiments on coupled pairs of spin-1/2 nuclei in the liquid phase. Previous discussions have assumed that in the homonuclear weakly coupled AX limit the modulation of the echo amplitude envelope depends only on the magnitude of the spin coupling and is independent of the pulse separation. Theoretical and experimental results are presented which show that in both AB and AX systems the modulation decreases in frequency and effectively disappears as the rf pulse separation decreases. (Author)
The Roles of Molten Salts in the Treatment of Aluminum

Abstract Fluxes based on a mixture of molten salts play an important role in the processing of molten aluminum. They are used in a passive role to cover the metal from oxidation and sometimes in an active role to remove inclusions, alkali metals and magnesium. Salt fluxes can also be used to improve metal recovery from drosses as well as during the melting of recycled scrap. Most salt fluxes are based on either the KCl-NaCl or the KCl-MgCl2 binary systems. Additives include other chlorides, fluorides, nitrates, carbonates or sulphates. The physical and chemical properties of these various molten salts are reviewed and analysed in terms of their applications to the aluminum industry. Les flux basés sur un mélange de sels fondus jouent un rôle important dans le traitement de l'aluminium fondu. On les utilise dans un rôle passif pour couvrir le métal contre l'oxydation et, quelque fois, dans un rôle actif pour enlever les inclusions, les métaux alcalins et le magnésium. On peut aussi utiliser les flux salins pour améliorer la récupération du métal de la crasse ainsi que lors de fonte du métal recyclé. La plupart des flux salins sont basés soit sur le système binaire KCl-NaCl ou soit sur le système binaire KCl-MgCl2. Les additifs incluent d'autres chlorures, des fluorures, des nitrates, des carbonates ou des sulfates. Les propriétés physiques et chimiques de ces divers sels fondus sont revues et analysées en rapport avec leur application dans l'industrie de l'aluminium.
The Dynamics of Nucleic‐Acid Single‐Strand Conformation Changes

1 The dynamics of the single-strand conformation changes of oligo- and polyriboadenylic acids has been investigated by a fast temperature-jump technique. Chemical rexalation processes have been observed in the range of 0.1 to 1 μs. The relaxation times are independent of the nucleotide concentration and also do not depend upon the pH within the range 6.9 to 9.2. The amplitudes correspond to those expected from thermal melting curves. According to these results the relaxation is assigned to the “single-strand helix-to-coil” transition. 2 Measurements af different wavelengths show that the relaxation times observed in the spectral range 240 nm to 270 nm are different from those observed around 285 nm by a factor of 2 to 3. This result demonstrates that the “helix-coil” transition of adenylic acid chains cannot be described by a simple all-or-none model with two reaction states. 3 As expected for a single-strand helix-coil transition there is a relatively small ionic strength dependence: a decrease of the salt concentration leads to an increase of the relaxation time. At high ionic strengths of monovalent ions (1 M and more) the appearance of relaxation times at 5 to 10 μs and in the ms range seem to indicate aggregation. 4 The presence of Mg2+ leads to a strong decrease of the amplitude around 285 nm, whereas the amplitude around 245 nm remains almost unchanged; the time constant of the 245-nm relaxation increases with increasing Mg2+ concentration. Apparently Mg2+ ions induce a specific shift of the riboadenylic acid chain conformation. 5 Measurements of the temperature dependence in the range of 0 to 50°C revealed an increasing rate of the conformation change with increasing temperature. The relaxation process measured around 245 nm is characterised by a higher apparent activation enthalpy than that measured around 285 nm. 6 The relaxation behaviour found for the polymer is also shown by oligoriboadenylic acids. The chain length dependence of the relaxation times is relatively small. The difference of the relaxation behaviour observed around 245 nm and around 285 nm extends to the dimer. Thus the observation of two different relaxation times cannot be explained by a cooperative effect. The relaxation time constants observed for oligo- and polyriboadenylic acids indicate the existence of energy barriers in the conformational transition. Similar time constants have been observed previously for the elementary process of base pairing in adenylic-uridylic acid double helices. The observation of two relaxation time constants for the conformation change of riboadenylic acid chains demonstrates the existence of more than two different conformation states.
Limiting Laws and Counterion Condensation in Polyelectrolyte Solutions II. Self‐Diffusion of the Small Ions

The concepts developed in Part I of this series are applied to the self‐diffusion of counterions and co‐ions. The condensed counterions are assumed to have no mobility, while the uncondensed counterions and all co‐ions execute Brownian motion subject to the locally inhomogeneous electric field created by the polyelectrolyte molecules. The polyelectrolyte field is assumed to have small amplitude, in analogy to the Debye–Huckel treatment of uncondensed mobile ions in Part I. The self‐diffusion coefficients of the counterion and the co‐ion are both less than the coresponding values in the absence of polyelectrolyte, but the coefficient for the counterion is much less than that for the co‐ion. The results for the self‐diffusion coefficient of the counterion in a salt‐free polyelectrolyte solution are in good agreement with experimental data.
Laboratory investigations of the interaction between benzene and bare silicate grain surfaces

Experimental results on the thermal desorption of benzene (C 6 H 6 ) from amorphous silica (SiO 2 ) are presented. The amorphous SiO 2 substrate was imaged using atomic force microscopy, revealing a surface morphology reminiscent of that of interplanetary dust particles (IDPs). Temperature-programmed desorption (TPD) experiments were conducted for a wide range of C 6 H 6 exposures, yielding information on both C 6 H 6 -SiO 2 interactions and the C 6 H 6 -C 6 H 6 interactions present in the bulk C 6 H 6 ice. The low-coverage experiments reveal complicated desorption behaviour that results from both porosity and roughness in the SiO 2 substrate, and repulsive interactions between C 6 H 6 molecules. Kinetic parameters were obtained through a combination of direct analysis of the TPD traces and kinetic modelling, demonstrating the coverage dependence of both desorption energy and pre-exponential factor. Experiments were also performed whereby the pores were blocked by pre-exposure of the SiO 2 to water vapour. C 6 H 6 was observed to be adsorbed preferentially on the SiO 2 film not covered by H 2 O at the temperature at which these experiments were performed. This observation means that intermolecular repulsion likely becomes important at smaller C 6 H 6 exposures on grains with a H 2 O mantle. Kinetic modelling of C 6 H 6 multilayer desorption yields kinetic parameters in good agreement with previous studies, with the SiO 2 having little impact on the desorption beyond the first few layers.
Cyberbullying Among Adolescents and Children: A Comprehensive Review of the Global Situation, Risk Factors, and Preventive Measures

Background: Cyberbullying is well-recognized as a severe public health issue which affects both adolescents and children. Most extant studies have focused on national and regional effects of cyberbullying, with few examining the global perspective of cyberbullying. This systematic review comprehensively examines the global situation, risk factors, and preventive measures taken worldwide to fight cyberbullying among adolescents and children. Methods: A systematic review of available literature was completed following PRISMA guidelines using the search themes “cyberbullying” and “adolescent or children”; the time frame was from January 1st, 2015 to December 31st, 2019. Eight academic databases pertaining to public health, and communication and psychology were consulted, namely: Web of Science, Science Direct, PubMed, Google Scholar, ProQuest, Communication & Mass Media Complete, CINAHL, and PsycArticles. Additional records identified through other sources included the references of reviews and two websites, Cyberbullying Research Center and United Nations Children's Fund. A total of 63 studies out of 2070 were included in our final review focusing on cyberbullying prevalence and risk factors. Results: The prevalence rates of cyberbullying preparation ranged from 6.0 to 46.3%, while the rates of cyberbullying victimization ranged from 13.99 to 57.5%, based on 63 references. Verbal violence was the most common type of cyberbullying. Fourteen risk factors and three protective factors were revealed in this study. At the personal level, variables associated with cyberbullying including age, gender, online behavior, race, health condition, past experience of victimization, and impulsiveness were reviewed as risk factors. Likewise, at the situational level, parent-child relationship, interpersonal relationships, and geographical location were also reviewed in relation to cyberbullying. As for protective factors, empathy and emotional intelligence, parent-child relationship, and school climate were frequently mentioned. Conclusion: The prevalence rate of cyberbullying has increased significantly in the observed 5-year period, and it is imperative that researchers from low and middle income countries focus sufficient attention on cyberbullying of children and adolescents. Despite a lack of scientific intervention research on cyberbullying, the review also identified several promising strategies for its prevention from the perspectives of youths, parents and schools. More research on cyberbullying is needed, especially on the issue of cross-national cyberbullying. International cooperation, multi-pronged and systematic approaches are highly encouraged to deal with cyberbullying.