Miracle-dz/UniFAR-FTUs huggingface dataset:
NO x formation pathways in lean-premixed-prevapourized combustion of fuels with carbon-to-hydrogen ratio between 0.25 and 0.88

Abstract NO x measurements in jet-stirred reactor (JSR) combustion of seven fuels are modelled using three complete chemical kinetic mechanisms. The two JSRs are operated at 1790 K, 1 atm, 2–4 ms, and the fuel-air equivalence ratio of 0.61. The modelled fuels are methanol, methane, ethane, ethene, propane, n-butane, and toluene. The experimental database also includes C1-C4 alkane mixtures, two light naphtas, four number two diesel oils, and benzene. The fuels and air are premixed, prevapourized, and preheated with a temperature-staged prevapourizer-premixer and an air-heater. Experiments show NO x and CO increase when burning fuels with increasing carbon-to-hydrogen ratio (from 0.25 to 0.88). The data are analysed using three complete chemical kinetic mechanisms: GRI 3.0 Mech. , CNRS' C1-C4 hydrocarbon oxidation mechanism, and CNRS' toluene oxidation mechanism. The modelling shows that the increase in NO x with the fuel carbon-to-hydrogen ratio is because of the increase in the NO formation via NNH, Zeldovich, and nitrous oxide pathways. The NNH pathway produces between 25 and 45 per cent of the NO formed. GRI 3.0 Mech. tends to favour this pathway since it forms more O, H, and NNH reactive species than the CNRS' C1-C4 hydrocarbon mechanism. Several rate constants for NNH + O → NH + NO are considered and best agreement using two and three perfectly stirred reactor schemes is found with the rate constant k = 7 × 1013 cm3/mol/s.
Population dynamics of molecular hydrogen and formation of negative hydrogen ions in a magnetically confined low temperature plasma

An attempt is made to unravel the influence of vibrational population distributions of molecular hydrogen in the electronic ground state on the formation of negative hydrogen ions in the volume of a magnetically confined low temperature plasma. The densities of rovibronically excited molecules are determined by laser-induced fluorescence spectroscopy and optical emission spectroscopy. Energy distributions of electrons are measured with a Langmuir probe and densities of negative ions are found by laser-induced photodetachment. A global model is presented that describes the stationary state of the molecular plasma. An overall view of the discharge is obtained on the basis of this model. This allows us to cross-check the obtained results for coherence. It also allows us to assess the relevance of specific processes and their dependences on the rovibronic molecular states and the discharge current. The influence of associative recombination of a hydrogen atom of the plasma bulk with a hydrogen atom adsorbed at the wall is discussed with respect to the influence of this process on the densities of other plasma particles, in particular the density of the negative ions.
Cellophane Membranes: Effect of their Treatment on the Permeability of Salts and the Membrane Potential

Membrane potential and diffusion of NaCl through treated and annealed Cellophane membranes have been studied. Some characteristic parameters of the different membranes such as salt permeability, fixed charge density and mobility ratio of the ions in the membranes were estimated. Salt permeability changes due to the treatment of the membranes have been obtained for the temperatures studied (25 and 55 °C). Results also show some differences in the fixed charge density values between treated and untreated membranes at 25 °C but very similar values have been found at 55 °C.
Mechanism of dc Electrical Breakdown between Extended Electrodes in Vacuum

A description is given of vacuum breakdown between extended copper electrodes in dc electric fields in terms of the relevant atomic‐collision processes. The theory is based on a model involving avalanche amplification of current in electrode vapor generated by the evaporation of an anode macroparticle during its transit to the cathode. Calculations are presented of the dynamics, heating, and evaporation of the macroparticle leading to the production of the vapor medium in the interelectrode gap. The inferred copper vapor density distribution accounts quantitatively for the absorption of resonance radiation measured just prior to current amplification in the gap. Calculations of electron avalanche multiplication in the vapor lead to predictions of breakdown conditions in agreement with our observations. The predicted size of the anode macroparticle which initiates breakdown is, on the average, of the order of 1 μ in diameter.
Particle Deposition in a Cast of Human Tracheobronchial Airways

Abstract Regional particle deposition efficiency and deposition patterns were studied experimentally in a human airway replica made from an adult cadaver. The replica includes the oral cavity, pharynx, larynx, trachea, and four generations of bronchi. This study reports deposition results in the tracheobronchial (TB) region. Nine different sizes of monodispersed, polystyrene latex fluorescent particles in the size range of 0.93–30 μm were delivered into the lung cast with the flow rates of 15, 30, and 60 l min− 1. Deposition in the TB region appeared to increase with the increasing flow rate and particle size. Comparison of deposition data obtained from physical casts showed agreement with results obtained from realistic airway replicas that included the larynx. Deposition data obtained from idealized airway models or replicas showed lower deposition efficiency. We also compared experimental data with theoretical models based on a simplified bend and bifurcation model. A deposition equation derived from these models was used in a lung dosimetry model for inhaled particles, and we demonstrated that there was general agreement with theoretical models. However, the agreement was not consistent over the large range of Stokes number. The deposition efficiency was found as a function of the Stokes number, bifurcation angle, and the diameters of parent and daughter tubes. An empirical model was developed for the particle deposition efficiency in the TB region based on the experimental data. This model, combined with the oral deposition model developed previously, can be used to predict the particle deposition for inertial effects with improved accuracy.
Increased Proton Relative Biological Effectiveness at the Very End of a Spread-Out Bragg Peak for Jejunum Irradiated Ex Vivo

Abstract Purpose: Currently, it is unclear if the variation in proton relative biological effectiveness (RBE) at different positions in the spread-out Bragg peak (SOBP) should be taken into account for medical applications. To date, the majority of studies have examined cells irradiated in vitro. In this work RBE estimates have been made for intact tissue irradiated ex vivo. Materials and Methods: Irradiations were performed in the 200 MeV clinical proton beam produced at iThemba LABS (Cape Town, South Africa). The beam was modulated to produce either a 3-cm or a 7-cm SOBP. The number of intestinal crypts regenerated in jejunum sections of mice after single doses of protons was used as the biological end point. For this, a novel ex vivo irradiation technique was implemented to allow measurements at the very end of the SOBP where most variations in proton RBE can be expected. Results: The proton RBE at the very end of the 7-cm SOBP increases by 10% compared with the middle of the SOBP; the same 10% increas.
Propriedades de solos sob vegetação nativa em Minas Gerais: distribuição por fitofisionomia, hidrografia e variabilidade espacial

One of the factors affecting the distribution of native vegetation is soil formation. Therefore, soils under native vegetation can be highly informative with regard to a region and the original soil fertility, as records of conditions found before agricultural reclamation (agrosilvopasture). The purpose of this study was to assess soil fertility and texture under native vegetation fragments sampled during the Forest Survey of the State of Minas Gerais, Brazil. In general, the variability in all soil properties was high, except for Al3+. In soils under grassy savanna (Campo Cerrado), the concentrations of soil organic matter were higher than in savanna woodlands (Cerradao and Cerrado Stricto Sensu). In general, seasonal forests were found on soils with higher fertility than Cerrado formations, whereas rainforests (Floresta Ombrofila) occurred on the most acidic and organic matter-rich soils. Linear regression analyses showed that the importance of soil organic matter for cation exchange capacity at pH 7.0 varied among the different vegetation types, and was irrelevant for seasonal deciduous forest (Decidual Seasonal Forest), but significant for the other phytophysiognomies. Data stratification by hydrographic basins, interpreted in combination with stratification by vegetation, allowed inferences about the probable effect of parent material on soil properties, especially on soil texture. By means of geostatistical analysis and based on ordinary kriging, maps of soil pH, organic carbon and clay contents, but not of cation exchange capacity at pH 7.0, were drawn for the state of Minas Gerais. Data of soils under native vegetation fragments could be used as reference standards of natural soil fertility, not only in Minas, but in other states of Brazil as well.
Determination of Selected Metals in Niger Delta Oils by Graphite Furnace Atomic Absorption Spectrometry

Abstract Graphite furnace atomic absorption spectroscopic (GFAAS) analysis of oil samples from the onshore and offshore fields in the Niger Delta was carried out in order to determine their trace element contents. The concentrations of the elements (Cr, Co, Cu, Fe, Mn, Ni, Pb, and V) determined ranged from 0.151–941.199 ppb with an average of 30.190 ppb (% RSD<5) for the oil samples analyzed. The pattern of occurrence of each element was in agreement with studies conducted employing neutron activation analysis and flame atomic absorption spectroscopy. From the cluster analysis of the data, two groups of oils were evident. The groups are correlated with each other, indicating common or similar genetic origin. Trace metal parameters indicate that the oils were generated from organic matter of strong terrestrial input. GFAAS proved to be a good method for the analysis of elemental composition and classification of Niger Delta oils. A. Akinlua is on a postdoctoral research visit from the Department of Chemistry, Obafemi Awolowo University, Ile‐Ife, Nigeria.
Chemical composition and antimicrobial activities of essential oil and its components from Lebanese Origanum syriacum L.

The chemical composition of essential oils isolated by hydrodistillation from the aerial parts of cultivated and wild Origanum syriacum were analyzed by gas chromatograph (GC) and GC/mass spectrometry (GC/MS). Regardless of growing habitat, both oils were characterized as carvacrol/γ-terpinene chemotypes. High in vitro antimicrobial activities of essential oil were attributed to the high content of phenolic derivative such as carvacrol. Total inhibition of fungal growth was achieved at 0.25–0.50 μL/mL of essential oil. Bacteria on the other hand, were slightly more susceptible to the essential oil with minimal inhibitory concentration (MIC) ranging from 0.15 μL/mL to 0.50 μL/mL. Carvacrol and thymol were the most detrimental compounds towards both bacterial and fungal microorganisms with inhibition concentration at 50% (IC50) ranging between 0.01 and 0.18 μL/mL for bacteria and with total inhibition of fungal growth at a range of concentrations between 0.25 and 0.75 μL/mL. Antimicrobial activities of α-terpinene, p-cymene and β-caryophyllene were comparable with the activities of crude oil extract against almost all microorganisms. p-cymene, however, stimulated mycelial growth of Metarhizium anisopliae.
EFFECTS OF NITRATE CONCENTRATION AND IONIC STRENGTH ON NITRATE ANION EXCLUSION UNDER UNSATURATED FLOW CONDITIONS

Transient unsaturated horizontal column experiments were conducted with a computer-controlled syringe pump to assess the impacts of nitrate (NO3−) concentration and solution ionic strength on anion exclusion processes that affect NO3− transport through soil. A loam soil was used in all the column experiments. Duplicate tests were conducted with seven different injection solutions applied at the inlets of relatively dry soil columns (initial volumetric water content averaged 0.018). The injection solutions contained either dissolved potassium nitrate (KNO3) alone or a combination of dissolved KNO3 and calcium chloride (KNO3 + CaCl2). These seven solutions allowed for the evaluation of the anion exclusion effects of four different NO3−-N concentrations (50, 200, 1000, and 2690 mg L−1) and four different solution ionic strengths (0.0036, 0.0142, 0.0714, and 0.1929 M) applied at the column inlet to be evaluated. Soil water content and soil solution NO3−-N concentration profiles were compared between tests with different injection solutions to quantify the effects of NO3− concentration and ionic strength on NO3− anion exclusion. Anion exclusion was exhibited in the NO3−-N concentration profiles for all experiments carried out in this investigation. Specifically, NO3−-N concentrations at the column inlet were 5% to 26% less than the injected NO3−-N concentrations, and NO3−-N concentrations at the wetting front were greater than injected NO3−-N concentrations by factors of 1.1 to 2.6. Considering results from tests conducted with both the KNO3 and KNO3 + CaCl2 injection solutions, it is apparent that ionic strength governs the magnitude of the NO3− anion exclusion effect to a far greater extent than the NO3−-N concentration. A strong logarithmic relationship (R2 ranged from 0.9474 to 0.9850) was found to exist between the injection solution ionic strength and various column inlet or wetting front parameters used to quantify the anion exclusion effect. Consequently, under unsaturated conditions, the anion exclusion process influencing NO3− mobility in the soil profile will be more affected by the valences and amounts of all anions and cations present in the soil solution and not so much by just the NO3− concentration.
An easy and fast test to compare total free radical scavenger capacity of foodstuffs

An easy and fast test has been designed to compare the total free radical scavenging capacity (RSC) of various food samples. Black and green teas from different countries, and wines of different brands were studied and compared as examples of coloured liquids (water- and methanol-soluble); oils from different sources were used as examples of lipidic foodstuffs; apples of different varieties and spinach were analysed as solid foods. Dilutions of extracts of the described foodstuffs were prepared and aliquots of each dilution were spotted onto TLC silica gel layers in the form of a dot-blot test: layers were stained with a methanolic solution of the 2,2-diphenyl-1-picrylhydrazyl radical. Dots of extracts of foodstuffs with RSC turned yellow, with a colour intensity depending on the RSC compounds present in the dilutions. After 1 h staining, the intensity of the yellow colour was measured with a chromameter (b* parameter) at one of the dilutions at which the colour value was linearly correlated to the concentration of the sample. According to these readings the different samples were organised in decreasing order of b* values, an order which corresponded to the decreasing order of RSC as determined by spectrophotometric methods. The dot-blot test was sensitive enough to detect differences of RSC between varieties and brands of water- or methanolsoluble products, but was not adequate for lipid-based compounds. The test was also able to follow the variation of RSC during food processing as in, for example, the heat-treatment of spinach. Copyright (C) 2000 John Wiley and Sons, Ltd.
Environmental fate of ceftiofur sodium, a cephalosporin antibiotic. Role of animal excreta in its decomposition

The degradation of ceftiofur sodium, a wide-spectrum cephalosporin antibiotic, was studied in the urine and feces of cattle, in three soils, and in buffers of pH 5, 7, and 9. Photodegradation was also studied. Fortification of cattle feces with [14C]ceftiofur showed that it was quickly degraded to microbiologically inactive metabolites. Sterilization of the cattle feces inhibited the degradation of ceftiofur, which suggests that microorganisms or heat-labile substances may be responsible for the degradation. The t1/2 values of aerobic degradation of ceftiofur sodium in California, Florida, and Wisconsin soil were found to be 22.2, 49.0, and 41.4 days, respectively. Hydrolysis of ceftiofur, as measured by either HPLC or microbiological methods, was accelerated by increasing pH. The t1/2 values at pH 5, 7, and 9 were 100.3, 8.0, and 4.2 days, respectively, at 22 degrees C and dramatically increased at 47 degrees C. The photodegradation of ceftiofur, as determined by HPLC and a microbiological method, showed that after initial degradation for several days the rate of degradation was minimal, probably due to a protective film formed from degradation products. A major role for feces in the degradation of ceftiofur was observed, although other pathways of degradation such as soil, light, and water were also important.
Fabrication and Properties of Porous Collagen/Hyaluronic Composite Scaffolds Containing Nano-Bioactive Glass for Tissue Engineering

In this work, nano-structured scaffolds were designed for tissue engineering using collagen, hyaluronic acid (HA) and nano-bioactive glass (NBAG) as their main components. The scaffold was prepared via freeze-drying method and the properties including morphology, porosity, compressive strength, swelling ratio and cytotoxicity in-vitro, were also evaluated. The composite scaffolds showed well interconnected macropores with the pore size of ranging from 100 to 500 μm. The porosity percent and swelling ability were decreased with the introduction of NBAG into the collagen/HA hydrogel; however, the compressive strength was enhanced. The cytotoxicity in-vitro study shows that the collagen-HA/NBAG scaffolds have good biocompatibility with improving effect on fibroblastic cells growth. It could be concluded that this scaffold fulfills the main requirements to be considered as a bone substitute.
Critical Link between Materials Chemistry and Cell-Level Design for High Energy Density and Low Cost Lithium-Sulfur Transportation Battery

A materials-to-system analysis for the lithium-sulfur (Li-S) electric vehicle battery is presented that identifies the key electrode and cell design considerations from reports of materials chemistry. The resulting systems-level energy density, specific energy and battery price as a function of these parameters is projected. Excess lithium metal amount at the anode and useable specific capacity, electrolyte volume fraction, sulfur to carbon ratio and reaction kinetics at the cathode are all shown to be critical for the high energy density and low cost requirements. Electrode loading is determined as a key parameter to relate the battery price for useable energy to the investigated design considerations. The presented analysis proposes that electrode loadings higher than 8 mAh/cm2 (∼7 mg S/cm2) are necessary for Li-S systems to exhibit the high energy density and low cost required for transportation applications. Stabilizing the interface of lithium metal at the required current densities and areal capacities while simultaneously maintaining cell capacity with high sulfur loading in an electrolyte starved cathode are identified as the key barriers for ongoing research and development efforts to address. © The Author(s) 2015. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND, http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is not changed in any way and is properly cited. For permission for commercial reuse, please email: oa@electrochem.org. [DOI: 10.1149/2.0611506jes] All rights reserved.
On the relationship between the dissociation of indicators in non-ideal acid solution and the dissociation of the acid itself

The study of the equilibria of weak bases in concentrated solutions of univalent acids has brought to light that, within experimental uncertainties, the Mc function is able to describe the dissociation of the acid itself; this allows the confident evaluation of thermodynamic equilibrium constants and leads to a new point of view in the field of concentrated ionic solutions.
Quality and dynamics of soil organic matter in a typical Chernozem of Ukraine under different long-term tillage systems

Kravchenko, Y. , Rogovska, N. , Petrenko, L. , Zhang, X. , Song, C. and Chen, Y. 2012. Quality and dynamics of soil organic matter in a typical Chernozem of Ukraine under different long-term tillage systems. Can. J. Soil Sci. 92: 429–438. Tillage has been reported to induce changes in soil organic matter (SOM) concentrations and quality. Conversion of plow-tillage to minimum till and no-till (NT) farming enhances the SOM pool. Enrichment of the SOM pool is essential for maintaining fertility of Chernozems, advancing food security, and improving the environment. The main objective of this study was to examine the effect of different tillage systems on the SOM concentration, its quality and dynamics including CO2 assimilation by heterotrophic bacteria and humus characteristics – the carbon (C) concentration in humic substances and the labile soil organic C fraction (SOCL) extracted with 0.1 N NaOH – as well as the molecular masses, spectroscopic parameters and physiological effects of humic acids on germinating.
Identification of Odorous Compounds in Fresh and Rotten Swine Manure

In order to elucidate the nature of malodor from piggery wastes, volatile compounds in fresh faeces, fresh urine, rotten urine, and rotten mixtures of faeces and urine were isolated by freeze vacuum distillation and continuous extraction and identified by gas chromatography-mass spectrometry. Many alcohols were detected not in fresh urine, but in faeces. Various fatty acids were determined at high concentrations in all samples, but their abundance was different in faeces and urine. Large amounts of phenols came from urine. Aromatic carboxylic acids were detected only in urine and decreased rapidly during digestion. Indole and 3-methylindole which were present only in faeces showed a reverse change of concentration during digestion.