Miracle-dz/UniFAR-FTUs huggingface dataset:
Antibacterial Activity of CNT-Ag and GO-Ag Nanocomposites Against Gram-negative and Gram-positive Bacteria

E-mail: chc12@chonnam.ac. kr (H. C. Choi); cwlee@jnu.ac. kr (C. W. Lee)Received July 4, 2013, Accepted August 9, 2013Carbon nanocomposites composed of carbon nanostructures and metal nanoparticles have become one ofuseful materials for various applications. Here we present the preparation and antibacterial activity of CNT-Agand GO-Ag nanocomposites. Their physical properties were characterized by TEM, XPS, and Ramanmeasurements, revealing that size-similar and quasi-spherical Ag nanoparticles were anchored to the surfaceof the CNT and GO. The antibacterial activities of CNT-Ag and GO-Ag were investigated using the growthcurve method and minimal inhibitory concentrations against Gram-negative and Gram-positive bacteria. Theantibacterial activities of the carbon nanocomposites were slightly different against Gram-positive and Gram-negative bacteria. The proposed mechanism was discussed.Key Words : Carbon nanostructures, Ag nanoparticles, Antibacterial activity, Gram-negative, Gram-positiveIntroductionAntibiotic resistance is a serious and growing phen-omenon in public health and a big task in the field ofpharmaceutical and medicine. Resistant pathogenic strainsare emerging at a rate that far exceeds the speed of newantibiotic development. Therefore, the novel class of anti-biotics having different mechanism of action in comparisonto existing antibiotics is urgently needed. In the research areaof antibiotics, development or searching of the antimicrobialcompounds having improved or distinct antibacterial activityagainst multidrug-resistant (MDR) human pathogenic micro-bes is a primary intention.
Vapor-liquid equilibrium in binary systems of chlorotrifluoromethane with n-butane and isobutane

La composition de la phase de l'equilibre liquide-vapeur du fluide de frigorigene avec le butane ou l'isobutane est determinee a 310,93; 350 et 400 K. Les donnees experimentales sont ajustees avec l'equation d'etat de Peng-Robinson et comparees avec le nouveau modele pour correler la constante de Henry a la constante de partage a dilution infinie pres du point critique du solvant
The effect of field parameters, nanoparticle properties and immobilization on the specific heating power in magnetic particle hyperthermia

Magnetic nanoparticles (MNP) are intended for utilization in cancer therapy as they produce damaging heat in the presence of AC magnetic fields. In order to reach the required temperature with minimum particle concentration in tissue the specific heating power (SHP) of MNP should be as high as possible. The aim was to clarify the influence of magnetic field parameters and nanoparticle properties on the SHP. As usual ferrofluids exhibit broad size distributions, a magnetic fractionation of a commercial iron oxide nanoparticle suspension was performed in order to obtain particles with varying properties. The fractions obtained were characterized by means of atomic force microscopy and magnetometry, among other techniques. Frequency spectra of the susceptibility show clear peaks at low frequencies related to the Brown relaxation. This effect vanishes after particle immobilization. Theoretical spectra considering experimentally determined size distributions are in agreement with experimental data. The SHP derived from AC susceptometry is in accordance with that directly determined by calorimetry. A maximum SHP of 160 W g−1 (400 kHz, 8 kA m−1) was detected for the largest particles, showing a behaviour in the transitional regime between superparamagnetic and stable ferromagnetic.
ZnO superstructures via oriented aggregation initiated in a block copolymer melt

A fast and simple one pot synthesis of ZnO nano- and microparticles initiated and driven by an amino block copolymer O,O′-bis(2-aminopropyl)polypropylene glycol-block-polyethylene glycol-block-polypropylene glycol (Jeffamine®) is reported. The specific building mechanism of ZnO mesocrystals is investigated in detail using electron microscopy and diffraction methods. Mesocrystals with a complex superstructure are formed as a result of a consecutive and oriented multiple stage aggregation process: first a 0D → 1D aggregation process is observed, then a 1D → 3D aggregation process occurs in which secondary particles form cones and multiple cone symmetries. Dots, rods, cones, and multiple cones have been isolated within a time resolved study which clearly supports the growth model. To control the morphology of the product particles, the influence of relevant synthesis parameters including stirring and sonication of the intermediate were investigated. Extensive surface characterization of the resulting mesocrystals is presented using infrared and photoluminescence spectroscopies as well as thermogravimetric analysis. Even after multiple washing steps, the particles exhibit a Jeffamine® coated surface that allows for easy dispersion in both polar and nonpolar solvents. The obtained mesocrystals efficiently scatter in the whole range of visible light.
Vaporisation of a Pyrophoric Substance: Borane Triethyl

A flow-through system is proposed for studying the evaporation rate of a pyrophoric liquid, borane triethyl (BTE), under various conditions of pressure and volume flow of inert (nitrogen). First, some basic aspects of the problem are presented. It is shown that the BTE partial pressure tends to a limit ing value that is lower than the saturated vapor pressure that can be obtained in closed box system, and that is a function of pressure and volume flow of inert. When this limiting pressure is reached, the mass flow rate of BTE vapor leaving the flow-through system is constant and equal to the evaporation rate. Therefore, such a procedure can be used for generation of controlled and stabilized BTE vapor-inert mixtures. Next, some experiments, conducted using strict precau tions, are presented. They allow for the determination of an evaporation constant for different initial masses of BTE liquid, and for different pressures and volume flows of inert.
Synthesis and Characterization of Thermochromic La0.75Ca0.25MnO3 Perovskite Manganites Nano-powders by Microwave-assisted Solution Combustion Synthesis

The microwave-assisted solution combustion synthesis was developed for application with initially synthesized thermochromic perovskite manganese oxide La0.75Ca0. 25MnO3 nano-powders. Dry and very fine powders were obtained after one-step combustion reaction for less than 10 min in a modified domestic microwave oven. The thermal behavior, phase formation and purity of the precursor, and as-synthesized and calcined powders, were investigated by TGA/DTA, X-ray diffraction (XRD) and FT-IR techniques. The morphology of the powder obtained was characterized using a scanning electron microscope (SEM). The XRD pattern and FT-IR results showed that as-synthesized La0.75Ca0. 25MnO3 powders were crystalline, and the monophasic perovskite phase occurred with an average crystallite size of 30.46 ± 5.54 nm for 6 h at a relatively low calcination temperature of 900°C. The small particle size obtained by SEM suggested a high specific surface area and high sinterability. This method was found to be simple, rapid and cheap, and an effective way to prepare nano-size perovskite powders.
Trap Density Determination by Space‐Charge‐Limited Currents

Trap depths and densities can be determined from the analysis of the dependence of space‐charge‐limited currents on applied electric field in insulators. Values obtained from space‐charge‐limited current measurements are compared with those obtained from thermally stimulated currents and from photocurrent decay on the same crystal of cadmium sulfide. The results indicate that gross errors in trap depth and density can be made if it is simply assumed that the rapid rise in current toward the trap‐free curve with increasing applied voltage always occurs when the traps are filled. Although this may sometimes be true, it is also possible for such a rapid rise to result from field ionization of the traps, or even in certain cases from the onset of double injection. Even if the latter effects occur, however, proper analysis of the space‐charge‐limited current data permits an evaluation of trap depth and density which is completely consistent with independent measurements of thermally stimulated current and photocurrent decay.
Lamellar-to-gyroid transition in a poly(oxyethylene)–poly(oxybutylene) diblock copolymer melt

The transition from the lamellar (lam) to the gyroid (gyr) phase in the melt of a poly(oxyethylene)–poly(oxybutylene) (EB) diblock copolymer was shown to proceed via an intermediate perforated lamellar (pl) structure. The transition was studied starting from a shear-oriented lamellar phase using synchrotron small-angle X-ray scattering (SAXS) with simultaneous rheology. The transition occurred with a continuous variation of q*, the position of the principal peak position, although the slope of q* as a function of temperature increased in the region of the transition (pl state). In the intermediate state, the variation of q* with T was shown to be much stronger than that of the radius of gyration of EB diblocks. It was observed that the gyr phase developed from an oriented pl phase precursor as an isotropic distribution of grains. This indicates that growth of this structure did not occur epitaxially on a macroscopic scale. Finally, density images corresponding to lam, hexagonal perforated lamellar and gyr structures were generated using a single wavenumber approximation, based on the SAXS evidence that diffraction patterns are dominated by the first Fourier component.
WAP (version 2.0): an updated computing and visualization server for water molecules

By exploiting the fast-growing Internet technology, the interactive computing server Water Analysis Package (WAP, version 2.0) has been updated with more flexible options to better understand the role of the water O atoms present in three-dimensional macromolecular (protein or nucleic acid) structures. The updated robust server facilitates the computation and visualization of water molecules from various hydration shells, interfacial water molecules and those water molecules that stabilize various secondary structural elements. It is also possible to detect the interactions of water molecules with various parts (polar atoms, nonpolar atoms, main-chain and side-chain atoms) of the protein molecule. Furthermore, a molecular graphics visualization program is interfaced to display the nature of the interactions of the water molecules. The Protein Data Bank archive interfaced with the server is updated every week; hence users get to analyse the latest structures. The computing server can be obtained from http://dicsoft2.physics. iisc.ernet. in/wap/.
Evaluation of environmental impact of the raised-bed-dike (Rong Chin) system along the Tha Chin river in Suphan Buri-Nakhon Pathom Provinces, Thailand

Abstract Vegetable cultivation on an embankment surrounded by water (raised-bed-dike system, Thai name rong chin) along the Tha Chin (Suphan Buri) river in the Suphan Buri and Nakhon Pathom Provinces was surveyed. The system was introduced by Chinese immigrants to produce vegetables in the river delta. The rong chin system in this area produced mainly Chinese kale, chili, bitter gourd, yard-long bean, taro, and sweet potato, while fruit trees and flowers were seldom cultivated, because of the flooding of the river in the rainy season. The amounts of nitrogen and phosphorus applied into field soils as fertilizers were far higher than those recovered in the harvested vegetables, indicating that only a limited portion of the nutrients was taken up by the crops and that part of the nutrients remained in the soils and in the dike water. Periodical flooding promoted leaching of the accumulated nutrients in the fields. Analyses of the soils and river waters revealed that phosphorus had started to accumulate in the environment, whereas only a small amount of nitrogen was detected in the river, canal, and dike waters, presumably because of the active uptake of nitrogen by biomass and denitrification.
Continuous Amonia and Hydrogen Sulfide Emission Measurements Over A Period of Four Seasons From A Central Missouri Swine Lagoon

The purpose of this research was to determine the influence of seasonal periods and environmental parameters including effluent temperature, air temperature, relative humidity, wind speed, and effluent concentration of hydrogen sulfide (H2S) and ammonia (NH3) on emission of H2S and NH3 from a central Missouri swine lagoon with a total surface area of 7,800 m2. The flux rate of H2S and NH3 was monitored semicontinuously for a period of four seasons using a nonintrusive, micrometeorological method. Emission rate of NH3 and H2S from the lagoon followed a predictable gaussian line shape with maximum emissions occurring in late July to early August. The maximum emission of NH3 from the lagoon was measured at 125.6 kg * day-1 (277 lbs * day-1), while maximum H2S emissions were 14.1 kg * day-1 (31 lbs * day-1). Emission models based on effluent temperature, pH, wind speed, and relative humidity were tested for their ability to predict the variability in emission rate of NH3, H2S, and the sparingly soluble gases, methane (CH4) and carbon dioxide (CO2). Effluent analysis data (NH3-N and H2S-SH) for NH3 and H2S was used to select an emission testing period when effluent concentration of NH3 and H2S remained essentially constant in the lagoon. Multi-component models based on effluent temperature, wind speed, and relative humidity for this sampling period could predict up to 91% of the variability in emission of the sparingly soluble gases, CH4 and CO2. However, under the same conditions, these models could only predict up to 64% of the variability in H2S emissions and up to 54% of the variability in NH3 emissions. These results indicate that there are considerable mechanistic differences that drive emission rate of sparingly soluble (CH4 and CO2) and polar, soluble (NH3 and H2S) gases from the animal effluent environment.
Association analysis of grain yield and its component traits in backcross inbred lines (BILs) of rice (Oryza sativa L.) under low phosphorus conditions

A set of twenty six backcross inbred lines of rice (Oryza sativa L.) were assessed to study inter-relationships of phosphorus stress tolerance related traits and yield related traits under low phosphorus stress conditions. Correlation analysis revealed that grain yield per plant exhibited highly significant positive association with harvest index (0.90), spikelet fertility (0.66), number of tillers per plant (0.38), filled grains per panicle (0.29), number of panicles per plant (0.28) and leaf P (0.27).
Soft X-ray Charging Method for a Silicon Electret Condenser Microphone

A novel charging method using soft X-ray irradiation for forming an electret of a silicon condenser microphone was developed. Soft X-rays can penetrate through the microphone diaphragm and are suitable for ionizing gas inside the microphone element. The surface potential of a positively biased SiO2/Si3N4 dielectric film negatively increased with irradiation time, since induced anions and electrons are dragged toward the film by an applied electric field. The charging rate is inversely proportional to the bias voltage and electrode-gap distance. Charged electrets have excellent retention properties; therefore, the method is promising for the realization of silicon-electret condenser microphones.
Crystal structure of 4-phenyl-5-(trifluoromethyl)-thiophene-2-carboxylic acid, C12H7F3O2S

Abstract C12H7F3O2S, triclinic, P1̅ (no. 2), a = 11.092(2) Å, b = 12.928(2) Å, c = 14.071(2) Å, α = 114.708(2)°, β = 104.991(2)°, γ = 90.827(2)°, V = 1753.2 Å3, Z = 6, Rgt(F) = 0.0374, wRref(F2) = 0.1101, T = 296 K.
Segregation Growth of Graphene on Cu–Ni Alloy for Precise Layer Control

A facile way to segregate wafer-size graphene with controllable layer number using Cu–Ni binary alloy under vacuum annealing condition is presented here. Increasing atomic percentage of Ni in Cu–Ni alloy was found to segregate thicker uniform graphene. To date, over 95% monolayer and 91% bilayer graphene films have been prepared by only changing atomic percentage of Ni in Cu–Ni alloy, respectively. The synergetic combination of the distinct carbon solubilities of Cu and Ni and the well-known segregation phenomenon is believed to be responsible for the formation of high-quality uniform few layer graphene. Together with the easy detachment from growth substrates, we believe this facile segregation technique will offer a great driving force for graphene research.
Controlled Permeability Polymer Membranes

The complex and interacting issues involved in effectively separating com­ mercially important gas mixtures using membranes are summarized in Figure 1. Oxygen and nitrogen separation from air are both important goals; however, nitrogen enrichment of air is much easier to achieve than oxygen enrichment of air with the current generation of membranes ( 1 ) . Nitrogen-enriched air streams can be produced at purities above 98-99% with ease, and higher purities can be achieved with the addition of catalytic units to remove traces of oxygen (2). Based on a recent analysis by Stern, no materials are currently satisfactory for economical large scale oxygen enrichment to greater than 30 mol% (3, 4), in spite of significant strides in this area of materials science over the past decade. Hydrogen separation from various supercritical gases is important in both refinery and chemical processing. With the emphasis on cleaner air, requiring hydrotreating of oil, the concept of hydrogen management has renewed interest in opportunities for hydrogen separation from waste and other marginal streams. Good membranes for this type of application exist; however, materials with improved thermal and chemical stability are still desirable for the demanding refinery and petrochemical industrial environments where such separations are practiced. The third major type of gas separation applications (Figure 1) pertains to the removal of acid gases such as CO2 and H 2S or simple water vapor contaminants from natural gases to meet pipeline specifications. Within this group of applications, carbon dioxide recovery is especially attractive
FIRST-PRINCIPLES ION-WATER INTERACTION POTENTIALS FOR HIGHLY CHARGED MONATOMIC CATIONS. COMPUTER SIMULATIONS OF AL3+, MG2+, AND BE2+ IN WATER

The concept of hydrated ion [M(H2O)m ]n+ has been used to describe interactions of highly charged monatomic cations in water. Ab initio interaction potentials for Al3+, Mg2+, and Be2+ have been developed on the basis of that previously applied to the Cr3+ hydration study (Martinez et al. J. Chem. Phys. 1998, 109, 1445). Transferability of the different contributions to the intermolecular potentials that describe the interactions between the central cation and the first hydration shell, Mn+−(H2O)I, and the hydrate with bulk water molecules, [M(H2O)m ]n+−(H2O)bulk, have been examined. Results indicate that a reduced number of points (∼40 quantum chemical computations) are enough to get the basic and differential features of each cation. MD simulations (200 ps) for the hydrate of each cation plus 512 TIP4P H2O have been performed. Structural properties such as RDFs among different pairs of atoms in the system and orientational parameter are presented. Likewise, dynamical properties such as self-diffusion coe.
Use of zincon to study uptake and accumulation of zinc by zinc tolerant and hyperaccumulating plants

Abstract A quick and cheap method to digest plant material using 2% sulphosalicylic acid and to analyze the extract for zinc (Zn) using the colorimetric agent zincon is described. It is shown that the recovery of Zn is excellent, within 90% of that determined by nitric acid digestion and atomic absorption spectrophotometry(AAS). The sensitivity is similar to the AAS. Its usefulness for investigating Zn uptake by the Zn hyperaccumulator Cardaminopsis halleri is investigated. Almost 50% of the variation between samples is due to between‐plant variance, with between‐leaf variation making up a further 37%. Some of the between‐leaf variance is due to age: young leaves contain less Zn than old leaves. In roots, root tips contain about twice as much Zn as root bases.
Role of singlet oxygen in photo‐oxidative degradation and photostabilization of polymers

Evidence is presented that singlet oxygen may have an important role in the photo-oxidation of polymers. Increased attention is being paid to singlet oxygen as a possible reactive intermediate in the initiation step of the photodegradation of polymers. Singlet oxygen may be produced by energy transfer either from impurities or internal groups after excitation, e.g. carbonyl groups, which are present in commercial polymers. As a consequence, reactions of singlet oxygen may also be important in the stabilization of polymers, e.g. leading to search for new and more effective antioxidants.
Speciation mapping of environmental samples using XANES imaging

Environmental context Recently developed fast fluorescence detectors have opened the way to the development of element speciation mapping, i.e. X-ray absorption near edge spectroscopy (XANES) imaging, of environmental samples. This technique is potentially very informative but is also highly data intensive. Here, we used XANES imaging to explore the distribution of Cu species in biosolid materials, destined for agricultural use, as this is of importance in relation to the bioavailability and potential toxicity of this metal. Abstract Fast X-ray detectors with large solid angles and high dynamic ranges open the door to XANES imaging, in which millions of spectra are collected to image the speciation of metals at micrometre resolution, over areas up to several square centimetres. This paper explores how such multispectral datasets can be analysed in order to provide further insights into the distribution of Cu species in fresh and stockpiled biosolids. The approach demonstrated uses Principal Components Analysis to extract the ‘significant’ spectral information from the XANES maps, followed by cluster analysis to locate regions of contrasting spectral signatures. Following this model-free analysis, pixel-by-pixel linear combination fits are used to provide a direct link between bulk and imaging XANES spectroscopy. The results indicate that both the speciation and distribution of Cu species are significantly affected by ageing. The majority of heterogeneously distributed micrometre-sized Cu sulfide particles present in fresh biosolids disappear during the oxidative stockpiling process. In aged biosolids most of the Cu is homogeneously redistributed on organic matter suggesting that Cu mobility is temporarily increased during this redistribution process. This manuscript demonstrates how large XANES imaging datasets could be analysed and used to gain a deep understanding of metal speciation in environmental samples.