Miracle-dz/UniFAR-FTUs huggingface dataset:
Fractal Dimension of Particle Aggregates in Magnetic Fields

ABSTRACT Particle flocculation plays a major role in water treatment processes. In flocculation kinetics models it is usually assumed that spherical particles collide and form spherical aggregates. Real aggregates, however, are of irregular shapes and can be considered as fractal objects. The structure of fractal objects can be described by a fractal dimension number that plays an important role in aggregation kinetics. Two-dimensional computer simulations of particle aggregation are carried out in this work to directly observe the evolution of floc size and to determine their fractal dimension. The computer program developed in this study simulates random particle motion as well as cluster growth. The simulation results are visualized using Java programming language. The fractal dimension of the simulated clusters is determined based on the linear relationship between log-(mass of clusters) and log-(radius of clusters). Primary forces acting on individual particles, including van der Waals, electrostatic, magnetic dipole, and hydrodynamic interparticle forces, are examined to determine the collision efficiency at different collision angles, as well as the structure of the aggregates. The effect of magnetic dipole forces on the fractal dimension and chain formation is examined. It is shown that when the magnetic dipole force is of the same magnitude as the double-layer force within a narrow range of zeta potential values, one-dimensional or two-dimensional clusters may be obtained.
Air separation by a small-scale two-bed medical O2 pressure swing adsorption

A small-scale two-bed six-step pressure swing adsorption (PSA) process using zeolite 13X was performed to provide oxygen-enriched air in the medical system. The binary mixture N2/O2 (79/21 vol %) was used for PSA experiments. Cyclic behaviors of the PSA process were investigated from unsteady- to steady-state conditions. Also, effects of various operating parameters on the PSA performance such as the P/F ratio, adsorption pressure, feed flow rate, and adsorption step time were investigated experimentally under the nonisothermal condition. The effect of the P/F ratio was noticeably changed according to the adsorption pressure and feed flow rate conditions. The higher the adsorption pressure, the slower the increasing rate of purity and the higher the decreasing rate of recovery. However, as the adsorption pressure became higher, the effect of the P/F ratio on the O2 purity became smaller. Furthermore, the effect of adsorption pressure on the O2 purity and recovery was diminished gradually to the increase o.
Study on the kinetics of lignin methylolation

The kinetics of lignin (ammonium-based lignosulfonate and sodium-based lignosulfonate) methylolation were studied in solution by monitoring the rate of disappearance of form-aldehyde and by using differential scanning calorimetry (DSC) techniques under an iso-thermal program, at 20, 40, 50, and 60°C, respectively. The kinetic parameters obtained from these two methods agree with each other. The results show that the degree of lignin methylolation depends on the number and availability of reactive sites per C9 unit of lignin. Lignin methylolation has a lower activation energy and a lower preexponential factor than that of phenol methylolation. Lignins took a shorter time to reach complete methylolation than did phenol at the low temperatures used here. © 1993 John Wiley & Sons, Inc.
Knowledge-Based B-Factor Restraints for the Refinement of Proteins

A new type of restraint for the B factors of atoms in low- to-moderate resolution models of proteins is proposed. This restraint incorporates the knowledge that the B factors of two atoms bonded to each other may be systemically different. In addition, some bonded pairs of atoms will be more consistent from structure to structure than others. With the use of B-factor restraints of this type, it is possible to construct models whose B factors are consistent with accurately known protein structures, even though only low-resolution crystallographic data are available.
Influence of foliar fertilisation with calcium fertilisers on the firmness and chemical composition of two highbush blueberry cultivars

Maintaining the high quality of fruits after harvest, which amongst other things is determined by firmness, is the aim producers strive after. Calcium, which fruits can be enriched with also in an extraradicular manner, is mostly responsible for the mechanical resistance of fruits. In the research conducted at the Laboratory of Orcharding, West Pomeranian University of Technology in Szczecin, the influence of foliar calcium fertilisers on the quality of fruits from two cultivars of highbush blueberry was studied. The firmness, size and chemical composition of fruits were examined (the content of mineral and organic compounds, especially polyphenols). At the fruit growth stage, bushes were sprayed 4 times with calcium solutions every 10 days, starting from the first decade of June. All fertilisers caused an increase in calcium concentrations in fruits (0.12-0.15 g 100 g-1), as compared with the control (0.09 g 100 g-1). The weight of 100 fruits collected from bushes sprayed with the Lebosol, Folanx and Calcinit fertilisers was the highest and it ranged from 327 to 365 g, and the Sunrise cultivar fruits were larger. The firmest (391 and 415 G mm) and the most resistant to mechanical damage (132 and 114 G mm) were the fruits sprayed with the calcium chloride and Folanx fertilisers, while fruits sprayed with Folanx and Calcinit were characterised by the highest polyphenol content (300 and 313 mg 100 g-1), and anthocyanins, among which delphinidin-3-galactoside predominated, constituted the largest group of compounds (77-80%). The Calcinit and Lebosol Calcium Forte fertilisers had the greatest influence on the change of chemical composition of the fruits, while the Folanx fertiliser had the greatest influence on the increase in fruit firmness. All calcium-based fertilisers decreased the acidity of fruits and, except for calcium chloride, they increased the nitrite level.
Heavy metal content in soil and plants from a pyrite mining area in Southwest Spain

Abstract Mineral content was measured in soils and leaves of eight woody plant species growing in a pyrite mining area in southwest Spain. The concentration of copper, manganese, zinc and aluminium in leaf tissues varied between species. The results are related to contrasting mechanisms, “excluders”; vs. “accumulators,”; of plant response to heavy metal stress. The lasting effects of pyrite melting activities on surrounding soil and plants were evaluated and compared with heavy metal values in a nearby forest.
Ellipsometric, Electrogravimetric, and Spectroelectrochemical Studies of the Redox Process of Sulfonated Polyaniline

Sulfonated polyaniline (SPAN) films were studied using simultaneous potentiodynamic, ellipsometric, spectroelectrochemical, and quartz crystal microbalance experiments. Ellipsometric experiments show that there is a small variation of film thickness (∼2%) between the reduced and oxidized states. The role of ionic transport during the redox reaction is emphasized in order to obtain information about all chemical species involved in the process occurring in the conducting polymer film. Quartz crystal microbalance results show the relevant participation of cations in the charge compensation process. The spectroelectrochemical study shows spectral changes accompanying the oxidation/reduction process of SPAN as the increase/diminution of the polaron band at 400 nm and another band at higher wavelengths as a function of potential. These changes were shown to be reversible.
Aging of a Commercial Graphite/LiFePO4 Cell

The aging behavior of a commercial 2.3 Ah graphite/LFP cell during a year of cycling or storage at either 25 or 45 � C is investigated. The performance decline of the cells during the aging period is monitored by non-destructive electrochemical techniques and is discussed in detail. An in-depth analysis of the aging results reveals that aging manifests itself more in terms of capacity loss rather than in terms of impedance increase, regardless of the cycling or storage conditions and of the temperature. The capacity fade is larger at 45 � C than at 25 � C, regardless of the cycling or storage conditions, and at a same temperature, cycling conditions are always more detrimental to capacity fade than storage conditions. The loss of cyclable lithium is identified as the main source of capacity fade in all cases, and for the cells aged at 45 � C, a partial loss of graphite active material is suspected as
ROUND BALE SILAGE STORAGE LOSSES OF RYEGRASS AND LEGUME-GRASS FORAGES

Round bales of ryegrass and legume-grass silages were wrapped with stretch film. Initial bale moisture contents ranged from 25 to over 65% (wet basis). After six months in storage, apparent dry matter losses were not affected by initial moisture content. Significant changes were measured in crude protein, acid detergent fiber, and total digestible nutrients for all forages. However, changes in quality were not significantly affected by initial moisture content. Final moisture content of samples bored from 0 to 100 mm (0-4 in.) and 100 to 230 mm (4 to 9 in.) depths ranged from 14.0% to 71.7%. Moisture content had a significant effect on fermentation. Ryegrass silage samples above 50% moisture content averaged 2.5% of DM lactic acid and 0.5% of DM acetic acid while legume-grass silages averaged 1.0% of DM lactic acid and less than 0.4% of DM acetic acid. Of the 312 samples analyzed, 17.9% had pH values above 6.5; a proportion that was relatively constant for samples having moisture contents less than 65%.
Convective instability by active stress

Composition-dependent stress fields in continuous and mechanically isolated material can, it is shown, initiate and maintain conversion of chemical to kinetic energy. Though the process is analogous to natural convection, neither the body force of the well-known buoyancy mechanism nor the singular inhomogeneity and anisotropy of the interfacial tension mechanism is required. In the cases examined, the material is represented by the constitutive relation for incompressible Newtonian fluid augmented by an active stress which must be anisotropic or nonlinear in concentration gradients (or other, equivalent gradients) in accordance with the oft-misquoted Curie principle. The concentration gradients are supposed to be sustained by steady chemical reaction (or an equivalent transformation process) throughout the material and by exchange with surroundings. Conventional linear analysis of asymptotic stability is used to identify types of stress/concentration-gradient coupling that can render a quiescent state of reaction and diffusion unstable when concentration gradients exceed critical values. It is found that both deviatoric (pure shear) and antisymmetric active stress can support two-dimensional convective instability in a cylinder of material in which the quiescent state is circularly symmetric. Certain cases of stationary instability are solved exactly. Others involving both stationary and oscillatory instability are treated by a new version of the Galerkin method. The results establish the possibility of generating fluid motion by mechanochemical means in continuous material having appropriate subcontinuum structure. Whatever their relevance to protoplasmic movement in biological systems they do contain challenges for experimental and theoretical fluid mechanics and related areas of rheology and chemistry.
Polyamides – Still Strong After Seventy Years†

Polyamides are a subject of enduring interest because of their variety, their complex internal structures, their commercial importance and versatility, and their various chemistries of preparation and of long-term use. The present review introduces these polymers and then discusses the first of the above aspects, namely the variety of the polyamides. Here, together, the full family is presented, classified conveniently according to the types and combinations of monomers from which they are constructed.
Lean and Rich Premixed Dimethoxymethane/Oxygen/Argon Flames: Experimental and Modeling

Experimental structures of two dimethoxymethane/oxygen/argon flames at equivalence ratios of φ = 0.24 and 1.72 have been studied by mass spectrometry. The detected species throughout the flame thickness were H2, CH3, CH4, H2O, C2H2, CO, CH2O, CH3O, O2, Ar, CO2, C2H4O2, and C3H8O2. The aim of this work was to extend an original model for ethylene combustion by building a sub-mechanism taking into account the formation and the consumption of oxygenated species involved in dimethoxymethane oxidation. By using kinetic data from the literature, the authors elaborated a new mechanism containing 480 reactions involving 90 chemical species in order to simulate these dimethoxymethane flames. The mechanism provides numerical results, which are in good agreement with experimental data for all species detected in both flames. Whatever the equivalence ratio of the flame, the two main degradation pathways of dimethoxymethane are the same: CH3OCH2OCH3 → CH3OCH2OCH2 → CH3OCH2 → CH2O and CH3OCH2OCH3 → CH3OCHOCH3 → CH3OCHO → CH3OCO → CH3O → CH2O, with the first being the fastest.
Chemical compositions of the leaf essential oils of some Annonaceae from Vietnam

The leaf oils of some genus of Annonaceae collected from Vietnam in December 2009 were analyzed by capillary gas chromatography (GC) and GC coupled with mass spectrometry (GC/MS). The major compounds identified in the oil of Artabotrys pallens Ast. were α-gurjunene (21.9%), α-phellandrene (20.1%) and bicycloelemene (9.6%). The oil of Goniothalamus tamirensis Pierre ex Finet & Gagnep. contained β-selinene (12.3%), bicyclogermacrene (10.9%), caryophyllene oxide (10.4%) and bicycloelemene (5.6%) in abundance. However, β-pinene (33.4%), α-pinene (32.3%) and β-caryophyllene (10.5%) were the most quantitative significant constituents of Dasymaschalon rostratum Merr. & Chun. From the oil of Uvaria pierrei Finet & Gagnep. we could identified bicycloelemene (18.3%), germacrene D (30.2%), bicyclogermacrene (26.4%) and β-bisabolene (7.7%) as the major compounds, while γ-elemene (54.0%) was the most singly abundant constituent of Uvaria dac Pierre ex Finet & Gagnep oil. All the other compounds were identified in amount less than 5% with the most prominent ones being myrcene (3.8%) and limonene (3.8%). In addition, the oil of Melodorum vietnamensis Ban. , had an abundance of α-pinene (15.4%), bicyclogermacrene (13.9%), bicycloelemene (10.8%) and β-caryophyllene (9.9%). The chemotaxonomic importance of the results was also discussed.
Evaluation of iron oxidation rate of Acidithiobacillus ferrooxidans in presence of heavy metal ions

The present study deals with the determination of the iron oxidation rate (IOR) of Acidithiobacillus ferrooxidans in the presence of various heavy metal ions. Initially, the IOR of this particular strain was enhanced to 718 mg L–1 h–1 by several sets of subculturing of the whole biomass in fresh medium. In the process, the bacterial regeneration time was determined to be 3˙7 h. The effect of various heavy metal ions (Hg, Ag and Pb) on IOR of this active strain was studied and the reaction kinetics in the presence of various concentrations of heavy metal ions in the solution has been determined. The tolerance index of the active culture to various heavy metals has also been established. The tolerance index in the presence of 700 mg L–1 Pb, 50 mg L–1 Ag and 0˙1 mg L–1 Hg was 5˙1, 5˙1 and 11˙9 respectively. Therefore, it was concluded that Hg ion rendered maximum toxicity to the bacterial strains followed by Ag and Pb. By statistical interpretation of the observed data, it was possible to formulate a very significant correlation between all the sets of experiments that were conducted in the presence and absence of metal ions.
Manganese dioxide-anchored three-dimensional nitrogen-doped graphene hybrid aerogels as excellent anode materials for lithium ion batteries

The capacity of manganese dioxide (MnO2) deteriorates with cycling due to the irreversible changes induced by the repeated lithiation and delithiation processes. To overcome this drawback, MnO2/nitrogen-doped graphene hybrid aerogels (MNGAs) were prepared via a facile redox process between KMnO4 and carbon within nitrogen-doped graphene hydrogels. The three-dimensional nitrogen-doped graphene hydrogels were prepared and utilized as matrices for MnO2 deposition. The MNGAs-120 obtained after a deposition time of 120 min delivered a very high discharge capacity of 909 mA h g−1 after 200 cycles at a current density of 400 mA g−1, in sharp contrast to only 280 and 70 mA h g−1 delivered from nitrogen-doped graphene aerogels and MnO2. This discharge capacity is superior to that of the previously reported MnO2/carbon based hybrid materials. This material also exhibited an excellent rate capability and cycling performance. Its superior electrochemical performance can be ascribed to the synergistic interaction between uniformly dispersed MnO2 particles with high capacity and the conductive three-dimensional nitrogen-doped graphene network with a large surface area and an interconnected porous structure.
De la hantise : le Marx de Derrida

Derrida intimide, comme si toute lecture etait d'emblee en defaut, ne rendant pas justice. Il faudrait tant d'attention et d'oreille et d'attention a tant de lieux et de jeux, d'effets, de resonances qui se repercutent, comme des echos en montagne, que l'eblouissement tourne en aveuglement ; la lettre s'echappe de la prise. La lecture s'affole. Sorte de deroute de la perception, peut-etre provoquee pour mieux ramener le regard precisement sur la lettre qui n'est pas une chose, mais son esprit, son fantome, son revenant.
Children's Health Deficits due to Diarrhoea: Effects of Water Supply and Sanitation Systems in Slums with Different Water Logging Conditions

This population-based epidemiologic study investigated the associations of individuals' socio-demographic statuses, sanitary systems and habits, water supply and drainage conditions with diarrhoea incidences among 707 children younger than 5 years who were living in slum communities with various water logging patterns in Dhaka, Bangladesh. We conducted a home-visiting survey during the pre-monsoon period from December 2006 to April 2007. Nine slum communities were selected that had been experiencing five different water logging conditions. One non-water logging community was selected as a control. The Disability Adjusted Life Years (DALYs) were calculated using data on diarrhoea morbidity and mortality. Although DALYs lost because of diarrhoea were very small in a non-inundation type community, but were the highest in persistent drainage inundation type communities. Among the factors correlated with DALYs, control variables for mother's illiteracy and household income strongly attenuated most of these correlations to statistical null, except for mother's age (less than 15 years-old), using hanging latrine and not washing hands before eating, and after defecation. In conclusion, water logging conditions and socio-economic statuses may strongly contribute to diarrhoea incidence in the city's slum communities. In such communities, interventions to address both water logging and socio-economic conditions may be critical for reducing diarrhoea incidences.
Magnetic Resonance In Situ Study of Tricalcium Aluminate Hydration in the Presence of Gypsum

The hydration of tricalcium aluminate, in the presence of gypsum, is investigated using in situ“real-time”1H NMR spin–spin relaxation, X-ray diffraction, and scanning electron microscope experiments. Aside from rapid ettringite formation within the first 45 min, it is shown that a re-distribution of water within the first 2 h contributes significantly to the retardation of the rate of hydration. From the 1H NMR component with T2 of approximately 20 μs, the continual disappearance of ettringite and the production of the layered monosulfate structure is monitored. In addition, the technique makes possible the monitoring of the change in the quantity of interlayer water in monosulfate, as well as the time scale associated with the decrease in the effective interlayer spacing, resulting from the ionic substitution of SO42− for OH−. The ionic substitution within monosulfate starts after approximately 9 h. Although it has been believed that the time scale for this reaction is fast, we have shown that it can take days to reach completion.
Intrinsic n-type Defect Formation in TiO2: A Comparison of Rutile and Anatase from GGA+U Calculations

The formations of intrinsic n-type defects, that is, oxygen vacancies and titanium interstitials, in rutile and anatase TiO2 have been compared using GGA+U calculations. In both crystal structures, these defects give rise to states in the band gap, corresponding to electrons localized at Ti3+ centers. O vacancy formation in rutile results in two excess electrons occupying 3d orbitals on Ti atoms neighboring the vacancy. Similarly, for anatase, two Ti 3d orbitals are occupied by the excess electrons, with one of these Ti sites neighboring the vacancy, and the second at a next-nearest Ti position. This localization is accompanied by one oxygen moving toward the vacancy site to give a “split vacancy” geometry. A second fully localized solution is also found for anatase, with both occupied Ti sites neighboring the vacancy site. This minimum is 0.05 eV less stable than the split vacancy and is thus expected to be present in experimental samples. A partially delocalized solution corresponding to the split vacan.
Hydrothermal Synthesis of MoS2 and Its Pressure-Related Crystallization

Abstract Crystalline, poorly crystalline, and single-layer MoS 2 were synthesized using a hydrothermal method at low temperature (170–200°C) through changing pressure and time. XPS, XRD, and TEM were used to study the products. It was found that the stacking of the single layers was closely related to the pressure in the autoclave. A model was presented to explain this phenomenon.
A reducing-difference IR-spectral study of 4-aminopyridine

The IR-spectra of 4-aminopyridine (4-AP) in solution and in the solid state have been analyzed, using the reducing-difference procedure. Defining a more precise band assignment of a part of the characteristic frequencies of 4-AP, the data obtained proved in particular a Fermi-resonance splitting of the symmetric NH2-stretch.
Toward a systematic determination of complex reaction mechanisms

Given a complex chemical reaction with an unknown or a partially known mechanism, we examine the possibility of determining the essential parts of the mechanism by a number of experimental methods, all of which rely upon the experimental evaluation of the stationary-state Jacobian matrix elements (JMEs). If the response by all species to a pulse perturbation of one of the species can be measured, then it is possible to determine all of the JMEs. A different experimental method, a concentration shift experiment, relies on measuring the change of steady-state concentrations in a chemical reactor after the inflow of each species has been altered. Another technique employs the induction (or cessation) of oscillations caused by a delayed feedback imposed on an inflow species