Miracle-dz/UniFAR-FTUs huggingface dataset:
Mixture reactivity in explosions of stratified fuel/air layers

The paper addresses one aspect of the definition of the explosion hazard from flammable liquid spills or slow heavy vapor releases in enclosures. In this type of accidents, the explosive mixture is typically confined to a layer near the floor. No methods are currently available for the sizing of explosion vents in these partial‐volume deflagrations. Resolution of the issue was sought through tests carried out in a 63.7 m3 (2250 ft3) chamber with stratified mixtures of propane in air. The layers were formed by slowly injecting propane at the chamber floor through diffusers, at a rate of the order of the estimated rate of vaporization of a typical solvent such as acetone. The layer composition was carefully characterized through gas concentration measurements at twelve locations, using a single continuous analyzer connected to a multiplexed sampling system. Following ignition of the layers, data were obtained on the propagation velocity of the flame and on the pressure developed by the explosion in the room both with and without venting.
Annual balances of CH4 and N2O from a managed fen meadow using eddy covariance flux measurements

Annual terrestrial balances of methane (CH4) and nitrous oxide (N2O) are presented for a managed fen meadow in the Netherlands for 2006, 2007 and 2008, using eddy covariance (EC) flux measurements. Annual emissions derived from different methods are compared. The most accurate annual CH4 flux is achieved by gap filling EC fluxes with an empirical multivariate regression model, with soil temperature and mean wind velocity as driving variables. This model explains about 60% of the variability in observed daily CH4 fluxes. Annual N2O emissions can be separated into background emissions and event emissions due to fertilization. The background emission is estimated using a multivariate regression model also based on EC flux data, with soil temperature and mean wind velocity as driving variables. The event emissions are estimated using emission factors. The minimum direct emission factor is derived for six fertilization events by subtracting the background emission, and the IPCC default emission factor of 1% is used for the other events. In addition, the maximum direct emission factors are determined for the six events without subtracting the background emission. The average direct emission factor ranges from 1.2 to 2.8%, which is larger than the IPCC default value. Finally, the total terrestrial greenhouse gas balance is estimated at 16 Mg ha−1 year−1 in CO2‐equivalents with contributions of 30, 25 and 45% by CO2, CH4 and N2O, respectively.
Experimental study of particulate products for aging of 1,3,5–trimethylbenzene secondary organic aerosol

Secondary organic aerosol (SOA) from the photooxidation of aromatic compounds is a very complex mixture containing products with a different chemical nature that are dependent on aging processes. In this study, we focus on the chemical characterization of major products that are formed from the OH–initiated oxidation of 1,3,5–trimethylbenzene and subsequent aging through OH–initiated reactions in the presence of NOx.The chemical composition of aged particles were measured in real–time by an aerosol laser time of flight mass spectrometer (ALTOFMS) coupled with Fuzzy C–Means (FCM) clustering algorithm. Experimental results demonstrated that methyl glyoxylic acid, 2–methyl–4–oxo–2–pentenoic acid, 3,5–dimethylbenzoic acid, 2–methyl–2,3–dihydroxyl–4–oxo–pentanoic acid, dimethyl–nitrophenol, 3,4–dimethyl–2–hydroxy–3–oxo–pentandioic acid, 2,4–dimethyl–2,3–dihydroxy–6–oxo–4–heptenoic acid, 2,4–dimethyl–4–hydroxy–2,3–epoxy– heptylic acid, 2,4–dimethyl–2,3,4–trihydroxy–5,6–dioxo–heptylic acid, and oligomer components were the predominant products in the aging particles. The possible reaction mechanisms leading to these aged products were also discussed and proposed.
Effects of Pb and Cu additives on microstructure and wear corrosion resistance behaviour of PM Al–Si alloys

The wear and wear corrosion resistance of Al–20Si–XPb–YCu (X=0–10 wt-%, Y=0–3 wt-%) alloys fabricated using powder metallurgy technique and subsequent heat treatments were evaluated using a block on ring tribotest. The microstructures of all aluminium alloys were observed using an optical microscope, a scanning electron microscope and an X-ray energy dispersive spectroscope. The evaluation studied the effects of applied potential and environments of dry air and 3·5 wt-%NaCl aqueous solution. The microstructural analysis showed that Pb was bimodally distributed in Pb containing alloys, and Cu particles formed the intermetallic phase CuAl2. Additionally, the hardness of both Pb and Cu containing alloys increased significantly. The wear and corrosion results showed that the addition of both lead (Pb) and copper (Cu) increased the wear resistance and the corrosion rate, while heat treatments reduced the corrosion rate of most alloys except the Al–Si alloy. Furthermore, comparison of all alloys following heat treatment shows that the wear corrosion resistance of Al–Si alloy is inferior to that of the other alloys. Therefore, addition of Pb and Cu further improved the wear corrosion resistance. Additionally, at anodic potential, the wear corrosion rate and current density of both Al–Si and Al–Si–Cu alloys containing particle Pb were significantly lower than those of alloys containing no Pb, because the layer produced by corrosion comprised Al, O and Pb elements.
Solid phase microextraction coupled to capillary electrophoresis

An on-column interface, coupling the solid phase microextraction (SPME) sampling technique with capillary electrophoresis (CE), has been constructed. This interface facilitates the direct insertion of a thin silica fiber into the inlet end of a separation capillary and, therefore, the zero-dead volume connection requirement for hyphenation between SPME and CE is fully realized. The performance of the interface was evaluated by SPME–CE analysis of the priority pollutant phenols using a laboratory-made 40 µm od poly(acrylate) (PA)-coated silica fiber connected to a 75 µm id separation capillary. The results clearly demonstrate that the interface is effective for on-line coupling SPME with CE.
Preparation of Alumina Nanowires by Etched Method in Acid Solution

Porous alumina films are obtained on aluminum piece by electrochemical method. In this work, we ues a kind of method for alumina nanowires by the alumina films. The result is showed with SEM. We study the effects of etching action in the dilute HF solution, and deduce the reason. We study catalyzed formaldehyde by the alumina nanowire supported titanium dioxide, results show that, the catalytic effect is better than activated carbon supported.
Electrochemical Characterization of Fluid Vesicles in Natural Waters

Abstract The electrochemical method of polarographic maximum based on the interfacial instability of a positively charged interface dropping mercury electrode/sea-water, allows a direct characterization of single events of coalescence and transformation of aggregates of fluid surfactants into adsorbed monolayers at the interface (relaxation times 10 – 500 ms, aggregation numbers > 109). Highly surface active aggregates, resembling those of unsaturated lipids, were detected in the sea surface microlayer samples and in the mixing layers in the estuaries, although the unsaturated lipids represent only a minor fraction (<10%) of the aquatic organic matter. Products of flocculation of dissolved organic matter during estuarine mixing resemble closely fluid vesicles released by marine microflagellate, such as Dunaliella tertiolecta, that was studied in a greater detail. The analysis of complex electrochemical responses in natural heterodispersion is developed using artificial dispersions of oleate and methyl ole.
Preparation of Radioactive Gibberellins A20, A5 and A8

Radioactive gibberellin A20 (GA20, I) was prepared by hydrogenation of GA5 methyl ester-16,17-epoxide with tritium gas followed by removal of epoxide oxygen and hydrolysis. Radioactive GA5(V) was obtained by hydrogenation of GA3 methyl ester monomesylate with tritium gas followed by hydrolysis and radioactive GA8 (XV) was obtained by oxidation of radioactive GA5 with osmium tetroxide.
Potassium-Containing Coal Chars as Catalysts for NOx Reduction in the Presence of Oxygen

The use of inexpensive potassium-containing coal chars for NOx reduction in a fuel-lean (oxygen-rich) environment has been investigated. Coals of different rank have been used as char precursors. Two types of experiments were performed to study the kinetics of the NOx/carbon reaction: (i) temperature-programmed reaction in a 15NO(0.5%)/O2(5%)/He mixture and (ii) isothermal reaction at 300 and 350 °C. NOx adsorption at room temperature was also carried out using an identical mixture. Two characteristic temperature regimes were identified: (i) At temperatures below 200 °C, NOx adsorption on the char surface is the more important phenomenon. (ii) At temperatures above 200 °C, the true NOx reduction by carbons starts with N2 and CO2 being the main reaction products. A very active potassium-containing coal char has been prepared by using the following char preparation conditions: pyrolysis at 900 °C and a KOH/coal ratio of 0.5/1.
COPPER–MANGANESE INTERACTION IN CAULIFLOWER

ABSTRACT Cauliflower (Brassica oleracea L. var. Botrytis) cv. Maghi was grown in refined sand supplied with complete nutrient solution with normal copper (Cu) and manganese (Mn) (1 ÂμM Cu; 10 ÂμM Mn) and in solutions deficient in either Cu (0.01 ÂμM) or Mn (0.1 ÂμM) or both Cu and Mn together to study the interactive effects of Cu and Mn. The effects of Cu deficiency at deficient Cu-normal Mn treatment, i.e., intensity of visible copper deficiency symptoms, reduced biomass, concentrations of Cu, DNA, RNA and decrease in activities of cytochrome c oxidase, acid phosphatase, and ribonuclease and increase in DNAse activity and phenol content in leaves were reversed in combined deficiency of both Cu and Mn reflecting an antagonism between Cu and Mn. Negative interaction was further observed when the effects of Mn deficiency at normal Cu-deficient Mn treatment, i.e., severity in Mn deficiency symptoms, decrease in biomass, Hill reaction, and acid phosphatase activity, concentrations of DNA, RNA, and increase in phenols and activities of cytochrome c oxidase and ascorbic acid oxidase were reversed when both Cu and Mn were in low supply together.
Etude des oxydes mixtes de lanthanides et de vanadium(V)

This work presents a study of the mixed oxides of vanadium(V) and lanthanides by dry methods. The study includes all elements of the rare earth group except cerium and promethium.All orthovanadates of the formula TVO4 were prepared and their lattice parameters redetermined for all lanthanides. New materials were synthesized: lanthanides 4T2O3•V2O5, for elements from samarium to ytterbium the compounds 5T2O3•V2O5• and for praseodymium and neodymium the compounds 6T2O3•V2O5. Identification of these materials was carried out by X-ray diffraction.
Hologram-based refractive index detector for capillary electrophoresis: separation of metal ions

A novel refractive index detector suitable for capillary separations is presented and demonstrate& in the capillary electrophoretic separation of metal cations in 10-μm-i.d. tubes. The principle of the detector is interferometric; it features a laser diode and, as the main optical element, a holographic optical element which performs several optical functions allowing the use of capillaries with inner diameters as small as 5 μm. In contrast to the «off-axis» method, the use of holographic plates permits probing of the capillary through its center, where the optical path is larger and diffraction effects are smaller. With ani.d. =10 μm capillary the detector resolves 2 μRIU and covers a linear dynamic range of three to four decades
A STUDY OF THE RECIPROCAL SALT PAIR: [K2, (NH4)2]–[SO4, CrO4] AT 25°C

The equilibrium of the reciprocal salt pair [K2, (NH4)2]–[SO4, CrO4] was studied at 25°. There exist two complete series of solid solutions in equilibrium with liquid solutions. The compositions of the solid solutions have been determined by a special method. The equilibrium of the system has been graphically represented using Janeck’s square diagram.
Confirmation of the new technique for measuring the linear thermal expansion of silicon

This paper further confirms that the direct measurement of diffraction angles at different temperatures by using the X-ray diffractometer is better than measurement of the lattice parameters for the rapid and accurate determination of the linear thermal expansion of silicon. High purity silicon has the linear expansion coefficient, α= (2.45±0.05) × 10−6/°C at room temperature. This value does not change for doped P-type and N-type silicon.
Fourier transform far infrared spectroscopy of a C4 bending mode

A study of the Fourier transform far infrared spectrum of the C4 radical produced by trapping the products of the vacuum ultraviolet photolysis of 1,3‐butadiene and acetylene in Ar at 10 K has resulted in the identification for the first time of a bending vibration at 172.4 cm−1. The assignment is confirmed by 13C isotopic data; is consistent with the earlier identification of the antisymmetric C=C stretching mode at 1543.4 cm−1; and is in agreement with the predictions of ab initio calculations for linear C4.
An Automated Dual-Wavelength Spectrophotometer Optimized for Phytochrome Assay

ABSTRACT A microcomputer-controlled dual-wavelength spectrophotometer suitable for automated phytochrome assay is described. The optomechanical unit provides for sequential irradiation of the sample by the two measuring wavelengths with intervening dark intervals and for actinic irradiation to inter-convert phytochrome between its two forms. Photomultiplier current is amplified, converted to a digital value and transferred into the computer using a custom-designed IEEE-488 bus interface. The microcomputer calculates mathematically both absorbance and absorbance difference values with dynamic correction for photomultiplier dark current. In addition, the computer controls the operating parameters of the spectrophotometer via a separate interface. These parameters include control of the durations of measuring and actinic irradiation intervals and their sequence. Because the data are processed solely within the microcomputer, except for the initial linear amplification, any output desired can be obtained, inc.
Energy relaxation by hot electrons in n-GaN epilayers

The energy relaxation rate for hot electrons in n-type GaN epilayers has been measured over the temperature range 1.5–300 K. Several samples grown by molecular-beam epitaxy and having different electron concentrations have been studied. At low electron temperatures (Te<20 K), the energy relaxation is via acoustic phonon emission. The magnitude and temperature dependence of the energy relaxation are found to be in good agreement with theoretical calculations using appropriate values of the deformation potential and piezoelectric coupling constants and ignoring screening. For Te⩾70 K, the dominant mechanism of energy loss is optic phonon emission. For the several samples studied, consistent values of the optic phonon energy and electron-optic phonon relaxation time, 90±4 meV and 5–10 fs, respectively, are measured. The energy agrees well with values obtained by other methods and the relaxation time is consistent with theoretical calculations of the Frohlich interaction and indicate that hot phonon effects a.
Investigations of nanocrystalline SnS films' surface morphology modification during inductively coupled argon plasma sputtering

In this work the investigations of the morphology, structure and chemical composition of nanocrystalline SnS films grown by hot wall deposition method on glass substrates before and after high-density low-pressure inductively coupled argon plasma sputtering were performed using scanning electron microscopy, x-ray diffraction analysis, Raman spectroscopy, and energy-dispersive x-ray spectroscopy. The phenomenon of the surface smoothing for the SnS films with petal-like nanocrystallites during plasma treatment is described and the low sputtering rate for the studied films is discussed.
The lytE Gene of Bacillus subtilis 168 Encodes a Cell Wall Hydrolase

ABSTRACT Bacillus subtilis cell wall-bound protein CWBP33 is encoded by lytE, a gene expressed during the exponential growth phase. Sequence analysis of LytE, a 33-kDa protein, reveals two domains. The N-terminal domain contains a threefold-repeated motif common to several peptidoglycan binding proteins, while the C-terminal domain, probably carrying the catalytic activity, has homology with certain exoproteins. Zymographs unambiguously reveal that the absence of CWBP33, due to inactivation of lytE, is accompanied by the loss of a lytic activity. In lytE mutants, the cell autolysis rate is significantly decreased, although autolysis of corresponding, purified cell walls does not seem to be affected.
Equilibrium Analysis of Thermochemical Cycles for Hydrogen Production

Abstract: Thermochemical cycles for production of hydrogen from water can be constructed by appropriate combination of hydrogen- and oxygen-producing reactions carried out at different temperatures. While hundreds of specific reaction schemes are possible, the individual reactions can be regarded as belonging to relatively few general types. On the basis of published thermochemical data, we describe a procedure whereby an equilibrium analysis of these reaction types can be carried out systematically for a large number of specific sets of reactants. This provides quantitative criteria for assessing the inherent thermodynamic viability of possible reaction cycles, which may be of use when coupled with the more practical considerations that have traditionally formed the basis for the design of thermochemical hydrogen-production schemes. Results of applying this thermodynamic screening process systematically to hydrogen production reactions involving a large number of metal-metal oxide and metal-metal oxide-carbon systems show that polythermal reaction schemes involving the latter systems are highly efficient in generating hydrogen from coal, in comparison with usual coal gasification processes.
Polymer‐Based Magnetoelectric Materials

Polymer‐based magnetoelectric (ME) materials are an interesting, challenging and innovative research field, that will bridge the gap between fundamental research and applications in the near future. Here, the current state of the art on the different materials, the used configurations for the development of sensors and actuators, as well as the main values of the ME coupling obtained for the different polymer‐based systems are summarized. Further, some of the specific applications that are being developed for those polymer‐based ME materials are addressed as well as the main advantages and remaining challenges in this research field.
Light stress provokes plastic and elastic modifications in structure and function of photosystem II in camellia leaves

Adaptation of plants to a continuously changing environment may be approached in terms of an optimisation strategy that is dictated by the thermodynamic demand for minimal entropy production. Any change in environmental input is a stressor in the sense that it disturbs optimality. Stress is defined by this disturbance and is therefore relative, with non-stress serving as the reference condition. Because of the thermodynamic demand for optimality, suboptimality forces the system to undergo a state change to a new optimal state. These state changes bring about the adaptation of the system. Any physical or chemical change that occurs during the adaptation processes is denoted as strain. In the present study, the polyphasic rise in chlorophyll (Chl) a fluorescence (OJIP) is used to investigate the behaviour of photosystem II in camellia leaves under different physiological steady states established by adaptation to different light regimes at both room temperature and 10°C. Analysis of the fast fluorescence rise according to the JIP-test allows establishment of structural and functional parameters, providing a quantification of the system's behaviour. The calculated functional parameters are the specific (per reaction center, RC) and phenomenological (per cross section of the sample, CS) energy fluxes for absorption (ABS), trapping (TR) and electron transport (ET). The flux ratios or the yields (the maximum quantum yield of primary photochemistry, φ p0 , the efficiency with which a trapped exciton can move an electron into the electron transport chain, ψ 0 , or the probability that an absorbed photon will move an electron into the electron transport chain, φ E0 ) are structural parameters provided by this test, as well as an expression of the concentration of the reaction centers (RC/CS). The photochemical (k P ) and nonphotochemical (k N ) de-excitation rate constants are also calculated. The present study focuses mainly on the response of photosystem II to cyclic environmental changes, denoted as the residual strain. The study investigates the adaptive processes in relation to the regulation of the different functional and structural parameters, as well as reversibility (elasticity) and irreversibility (plasticity). Having screened camellia leaves for several environmental changes, we observed that the various structural parameters undergo modification that differ in both their extent and degree of elasticity, which indicates that different survival strategies are employed in response to stress.