Miracle-dz/UniFAR-FTUs huggingface dataset:
Phosphate sorption by red mediterranean soils from Greece

Abstract In nineteen surface horizons of red Mediterranean soils from various locations of Greece, phosphorus (P) sorption experiments were conducted and the sorption characteristics were studied in relation to soil properties. Phosphate sorption data were fitted both to the Langmuir and Freundlich equations. From these equations, the following P sorption parameters were determined from the Freundlich equation, X = ACn, the parameters A (the phosphate sorbed at C = 1 mg P/L), n (the P sorption intensity), the P sorption index (PS = X/log C) and maximum P sorption (Xmfr). From the Langmuir equation, C/X = 1/KXm + C/Xm, the parameters K (showing the bonding energy), maximum P sorption (Xmla), the quantity of P adsorbed at a standard concentration of 0.2 mg P/L (P0.2), and P maximum buffering capacity (PMBC). The Freundlich parameter A was strongly correlated to the clay and sesquioxides ("free”; iron and aluminum oxides and amorphous iron oxides) content. Seventy‐four percent of the variance of this paramet.
Towards novel wood-based materials: Chemical bonds between lignin-like model molecules and poly(furfuryl alcohol) studied by NMR

Abstract Wood modification with furfuryl alcohol is a non-toxic alternative to conventional preservation treatments. A process in which furfuryl alcohol polymerises in situ was previously proposed for chemical modification of wood. In the present work, liquid model systems were investigated using compounds that resemble repeating units of lignin to verify whether chemical bonds form between the furfuryl alcohol polymer and wood. Using different NMR spectroscopic techniques we confirmed that these model compounds do form covalent bonds with the polymerising polymer. The results indicate that the furan polymer grafts to lignin, supporting observations in similar studies performed with genuine wood materials.
Chiroptical studies. Part 101. An empirical analysis of circular dichroism data for steroidal and related transoidαβ-unsaturated ketones

An empirical analysis of c.d. data for steroidal and related transoidαβ-unsaturated ketones substantially confirms existing helicity ‘rules’ for the n→π* and π→π* Cotton effects, and shows that the signs and magnitudes of ΔIµ depend essentially upon the structural class of the bicyclic component containing the chromophore. The third c.d. band, in the region 200–220 nm, has the characteristics expected for the olefinic πx→πy* transition, and is relatively insensitive to the immediate environment of the carbonyl group.
Alkyloximes and Imines via Silyl Carbamates

Abstract The reactions between different N,O-bis-trimethylsilyl-carbamates and oxo compounds were studied. The N,O-bis-trimethylsilyl-N-methoxy-carbamate converts ketones to the corresponding O-methyl oximes. The product is usually a mixture of syn and anti isomers. If the carbonyl compound bears a hydroxyl group, the oxime formation and the O-silylation take place simultaneously. In the case of α-haloketones, the undesired substitution of halogen was not observed. The reactions between N,O-bis-trimethylsilyl-N-methyl-carbamate and oxo compounds resulted in the corresponding imines, although the yield are moderate in some cases. Analoguos reaction of ferrocenylated oxo derivatives gave similar results.
Temperature dependence of MOS transistor characteristics below saturation

The temperature dependence of MOS transistor characteristics in the region below saturation is studied theoretically and experimentally. The variation of channel conductance with temperature is shown to be due to the variation of the threshold voltage and of the inversion layer mobility. Both variations can be predicted in reasonable agreement with experimental observations. It is shown that the role of fast surface states in determining the temperature dependence is negligible.
Characterization of a Cation-Exchange/Polyaniline Composite Membrane

A composite membrane was prepared by chemical polymerization of a thin layer of polyaniline (PANI) in the presence of high oxidant concentration on a single face of a sulfonated cation-exchange membrane (Neosepta CMX from Tokuyama Soda Inc.). The CMX−PANI composite membrane was characterized as a function of the polymerization time by cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), and ion-exchange capacity (IEC) measurements. CV and XPS results demonstrate that, under our experimental conditions, the maximum PANI loading is attained after 1 h of polymerization. This is accompanied by a decrease in membrane ion-exchange capacity due to the presence of the cationic PANI acting as counterions for the sulfonate groups of the membrane. The optimal membrane permselectivity for protons against bivalent metallic cations (Zn2+ and Cu2+) was also found at a polymerization time of 1 h. In fact, at longer polymerization times, XPS data indicate the occurrence of PANI degradation. UV−visible spectros.
The effects of treatment with polyamines on dry matter and some metabolites in salinity - stressed chamomile and sweet majoram seedlings

The seeds of two medicinal plants, namely Chamomilla recutita (Babong) and Origanum majorana (Bardaqoush) were subjected to germination in different NaCl concentrations, polyamines (putrescine, spermidine, spermine) and to combination of both. The results revealed that the growth alterations induced by NaCl were alleviated by various levels of polyamines. The organic solutes of both plant seedlings exhibited somewhat variable responses to various salinity levels or polyamines treatments and in combination of both treatments. Putrescine in Ch. recutita seedlings was more effective in alleviating the stress effects of salinization than spermidine and spermine, while in O. majorana seedlings spermidine was more effective. Generally, the degree of stimulation differed according to the type, concentration of the additive used and the type of the plant tested.
ULTRAFAST STUDIES OF EXCITED-STATE DYNAMICS OF PHTHALOCYANINE AND ZINC PHTHALOCYANINE TETRASULFONATE IN SOLUTION

Femtosecond measurements of transient absorption, bleach, and stimulated emission are used to study the excited-state dynamics of phthalocyanine tetrasulfonate (PcS4) and zinc phthalocyanine tetrasulfonate (ZnPcS4) in solution. In water the excited-state decay process is fast and dominated by energy relaxation due to intermolecular aggregation. In dimethyl sulfoxide (DMSO) both PcS4 and ZnPcS4 exist predominantly in the monomeric form and exhibit very different dynamics from that of the aggregates. The decays are much slower and the observed processes are strongly dependent on the probe wavelength. For PcS4 in DMSO, when probed at 790 nm, the dynamics are dominated by stimulated emission which is observed for the first time in solution. At other wavelengths either transient absorption or bleach dominates the signal. All the observed dynamics can be well fit using a double-exponential function with a fast and slow component. The fast decay has a time constant of 10 ± 4 ps for both phthalocyanines while the.
Chemistry of adamantane. Part IX. 1,2-Difunctional adamantanes; synthesis and reactions of protoadamantane-4-spiro-oxiran

The synthesis of protoadamantane-4-spiro-oxiran {octahydrospiro[2,5-methano-1H-indene-7,2′-oxiran]} and its isomerisation to protoadamantane-4-carbaldehyde are described. Electrophilic cleavage of the oxiran ring with simultaneous rearrangement gives 1,2-difunctional adamantane derivatives. Reactions of lithium carbenoids, from benzylidyne chloride and benzylidene bromide, with protoadamantan-4-one mainly lead to protoadamantan-4-yl phenyl ketone. 4-Phenylprotoadamantan-4-ols on treatment with acid preferentially undergo elimination to give 4-phenylprotoadamantene.
Antimicrobial activity of chitosan nanofibers obtained by electrospinning

Chitosan is a natural polymer with both antimicrobial activity and nanofiber-forming capability. The electrospinning technique allows the production of chitosan nanofibers but still faces several problems such as the small number of suitable solvents for the process and the large number of factors affecting quality and production of the nanofibers, among others. The antimicrobial properties of chitosan nanofibers have been little studied; therefore, the most probable mechanism of action and the effect of the conformation or arrangement of the molecules in the nanofibers remain unknown. The presence of residual solvent in the materials is one factor that has complicated the assessment of the antimicrobial activity of chitosan nanofibers. The research in this area will be very important for the future of these materials. Copyright © 2011 Society of Chemical Industry
Updating soil information with digital soil mapping

De Bodemkaart van Nederland, schaal 1:50.000, is de belangrijkste bron van bodeminformatie in Nederland. Deze kaart raakt echter in gebieden met veengronden verouderd. Door intensief gebruik van deze gronden verdwijnt het veen. Actualisatie van de bodemkaart is daarom noodzakelijk. Bas Kempen promoveerde op zijn onderzoek hiernaar.
Intercomparison of Experimental Regional Aerosol Deposition Data

ABSTRACT A critical review is presented of the available experimental data on regional aerosol deposition in man. The data agree well for nasal and extrathoracic deposition. For the fast and slow cleared components of thoracic deposition, however, agreement is less satisfactory. The different experimental techniques are critically evaluated, and possible reasons for the observed discrepancies are discussed. Additionally, a semi-empirical model is presented which takes this evaluation into account, and which enables regional deposition to be calculated as function of particle size and respiratory parameters without lengthy computer models. The proposed equations explain and eliminate some of the intra- and inter-individual scatter of the data, and some of the discrepancies between the data from different laboratories. Where these discrepancies could not be eliminated, an additional 'conservative' model for dose estimations is offered which takes account of the uncertainty inherent to the data. A summary of.
Trace Metal Concentration in Crops and Soils Collected from Intensively Cultivated Areas of Sri Lanka

Intensification of agriculture is likely to result in the accumulation of trace metals due to the excessive use of agrochemicals and amendments. Although agricultural soils can be a long-term sink for trace metals, data on trace metal concentrations are not available for Sri Lankan soils and crops. The objectives of this study were to determine the concentrations of Cd, Cu, Ni, Pb and Zn in soils and vegetable crops in locations where intensive agriculture has been practiced for more than 10 years and to establish relationships between trace metal accumulation and soil properties. Soils were collected at depths of 0–20 cm under vegetable crops from 40 agricultural soils of low country ( 300 m elevation) wet zones (1700–3300 mm of annual rainfall) of Sri Lanka. Soil pH, CEC, organic matter % and available P and K were determined to establish the relationship between soil trace metal accumulation in soils and soil properties. Crops that were grown in the fields where the soils were collected were analyzed for trace metals. The mean concentrations (mg kg-1) of the trace metals in the soils ascended as follows: Cd (1.18±0.26) < Ni (21±5) < Cu (51±26) < Pb (54±49) < Zn (173±62). Among the tested soil properties, pH, CEC and available P showed significant positive correlations with some trace metals. Mean values (mg kg -1 dry weight) of the trace metals in the plants were 0.59±0.44 for Cd, 11±6 for Cu, 13±9 for Ni, 8±3 for Pb and 40±20 for Zn. Elevated levels of Cd, Cu, Ni, Pb and Zn were observed in both the up country and low country wet zone soils, compared with uncultivated soils. Measured mean values of Cd in a few soils exceeded the maximum allowable limits imposed by the CEC 1986 standard; however, Cd concentrations in the tested vegetable crops were below the maximum permissible levels given by the WHO/FAO in 2009. The Cd to Zn ratio in the studied soils indicated safer limits for Cd in more than 95% of the studied soils. These results provided initial evidence of accumulation of trace metals in Sri Lankan soils and leafy vegetables, emphasizing the importance for further investigations.
Oscillatory burning of solid propellants including gas phase time lag.

Abstract An analysis has been performed for oscillatory burning of solid propellants including gas phase time lag. The gaseous flame is assumed to be premixed and laminar with a one-step overall chemical reaction. The propellant is assumed to decompose according to the Arrenhius Law, with no condensed phase reaction. With this model, strong gas phase resonance has been found in certain cases at the characteristic gas-phase frequencies, but the peaking of the acoustic admittance is in the direction favoring the damping of pressure waves. At still higher frequencies, moderate wave-amplifying ability was found. The limit of low frequency response obtained previously by Denison and Baum was recovered, and the limitations of the quasi-steady theory were investigated.
Flow Injection Spectrophotometric and Chromatographic Determination of Ciprofloxacin and Norfloxacin in Pharmaceutical Formulations

Methods based on flow injection analysis (FIA) and high-performance liquid chromatography (HPLC) have been developed for the determination of ciprofloxacin (CIP) and norfloxacin (NOR) in pharmaceutical dosage forms. The FIA method is based on the measurement of absorbances of the red complexes formed between iron (III) and the studied drugs at 440 nm. Optimization of chemical and FI variables has been made. Under the optimized conditions, the sampling rate was over 80 h -1 . For the chromatographic method, a reverse phase Suplico LC8 column (7.5 cm * 4.6 mm i.d, 3μm dp) was used at ambient temperature. The mobile phase finally selected was prepared by using ACN: 0.005 M H3PO4 (30:70) adjusted to pH = 4.98 by TEA. The developed methods have been successfully applied for the determination of ciprofloxacin and norfloxacin in pharmaceutical formulations. The common excipients and additives did not interfere in their determinations. The results obtained by the proposed methods have been statistically compared by means of Student t-test and by the variance ratio F-test.
Changes in the Properties of a Montmorillonite-Water System during the Adsorption and Desorption of Water: Hysteresis

Samples of Na-saturated, Upton montmorillonite were prepared with different contents of water (H2O or D2O) by: (1) adsorption of water from the vapor phase at a specific value of p/p°, the relative humidity, (2) adsorption of water from the vapor phase at p/p° = 1.0 followed by desorption of the water into the vapor phase at a specific p/p° < 1.0, and (3) adsorption of water from the liquid phase followed by desorption of the water into the vapor phase at a specific p/p° < 1.0. Water adsorbed initially from the vapor phase was called V-adsorbed water, and water adsorbed initially from the liquid phase was called L-adsorbed water. The water contents of these samples were determined by gravimetric analysis, the c-axis spacings by X-ray powder diffraction, the O-D stretching frequencies by IR spectroscopy, and the heats of immersion by differential microcalorimetry. No difference was found between V-adsorbed and L-adsorbed water; however, if the final water content was established by adsorption, the system was in a different state than if the final water content was established by desorption. In particular, hysteresis was observed in the following properties: the relative humidity of the adsorbed water, the O-D stretching frequency in this water, and the degree of order in the stacking of the clay layers. The only property that did not exhibit hysteresis was the heat of immersion. Apparently, hysteresis occurred because the orderliness of the system was not reversible, and, thus, any property that depended on orderliness was hysteretic.
Capacitated Shortest Path Tour Problem-Based Integer Linear Programming for Service Chaining and Function Placement in NFV Networks

Network functions virtualization (NFV) is a new paradigm to achieve flexible and agile network services by decoupling network functions from proprietary hardware and running them on generic hardware as virtual network functions (VNFs). In the NFV network, a network service can be modeled as a sequence of VNFs, called a service chain. Given a connection request (e.g., origin, destination, and a sequence of required functions), we have to solve both the service chaining and function placement problems to find an appropriate service path that optimizes the objective (e.g., minimization of the total path delay) while satisfying the service chain requirements. In this article, focusing on the similarity between the service chaining problem and the shortest path tour problem (SPTP) and developing the novel network model called augmented network, we formulate capacitated SPTP-based integer linear programs (ILPs) for the service chaining and function placement. Through numerical results obtained by the existing solver, we show the proposed ILP for the service chaining can support 1.22–1.90 times as large-scale systems as the existing ILP. Furthermore, we also demonstrate that the proposed ILP for both the service chaining and function placement can shorten the total delay by 15.8% compared with that only for the service chaining. For further scalability, we propose a shortest-path-based heuristic algorithm to solve the ILPs and show the heuristic for service chaining and function placement can calculate the optimal solution with high accuracy in strongly polynomial time.
Succession and phylogenetic composition of eubacterial communities in rice straw during decomposition on the surface of paddy field soil

Abstract To estimate the bacterial communities in rice straw left on the soil surface of paddy fields, polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis was conducted. Rice straw samples were placed on the soil surface in a Japanese paddy field under drained conditions after harvest and under flooded conditions after the transplanting of rice. The residual samples on the soil surface under upland conditions were collected just before spring plowing and were replaced again on the soil surface after transplanting, under flooded conditions. The DGGE patterns of the bacterial communities in rice straw on the surface of paddy field soil were divided into three groups, namely rice straw samples before placement, under drained conditions and under flooded conditions. Sequence analysis of DGGE bands indicated that most of the bacterial members in rice straw during decomposition on the soil surface in the paddy field belonged to Gram-negative bacteria. The bands that commonly existed throughout the periods under flooded and upland conditions were closely related to α-Proteobacteria. The groups of Spirochaetes and δ-Proteobacteria were often observed during flooded periods, although the members of Bacteroidetes, α-Proteobacteria, Gemmatimonadetes and Actinobacteria were also detected under flooded conditions. In contrast, the bands characteristic to the rice straw left on the soil surface of the paddy field under drained conditions belonged to Bacteroidetes and γ-Proteobacteria. This finding clearly indicates that the bacterial communities responsible for rice straw decomposition were determined by the water regime in the paddy field, and various members of Gram-negative bacteria have contributed to the decomposition of rice straw left on the soil surface in a paddy field.
A coupled population balance model and CFD approach for the simulation of mixing issues in lab-scale and industrial bioreactors

Lab-scale (70 L) and industrial scale (70 m3) aerated fermenters are simulated using a commercial computational fluid dynamics code. The model combines an Euler-Euler approach for the two-phase flow, a population balance model for biological adaptation to concentration gradients, and a kinetic model for biological reactions. Scale-up at constant volumetric mass transfer coefficient is performed, leading to concentration gradients at the large scale. The results show that for a given concentration field and a given circulation time tc, the population (physiological) state depends on the characteristic time of biological adaptation Ta. The population specific growth rate (Ta≫tc) is found independent of the spatial location and closely related to the volume average concentration. Oppositely, the population specific uptake rate (Ta∼tc) is spatially heterogeneous. The resulting local disequilibria between the uptake rate and the growth rate provide an explanation for the decreased performances of poorly macromixed industrial bioreactors. © 2013 American Institute of Chemical Engineers AIChE J, 60: 27–40, 2014
Silicon nanocrystal formation in annealed silicon-rich silicon oxide films prepared by plasma enhanced chemical vapor deposition

Silicon-rich silicon oxide films deposited by plasma enhanced chemical vapor deposition with different total Si contents (from 39to46at.%) have been annealed at increasing temperature (up to 1250°C) in order to study the Si nanocrystal (Si-nc) nucleation as well as the structural changes induced in the amorphous embedding matrix. The comparison between x-ray absorption measurements in total electron yield mode, Raman spectroscopy, and photoluminescence spectra allowed us to gain insight about the Si nanocrystal formation, while the chemical composition and the nature of chemical bonds into the oxidized matrix was studied by Fourier transform infrared spectroscopy. A comprehensive picture of the nucleation process has been obtained, demonstrating the active role played by the hydrogen and nitrogen atoms in the formation of Si-nc and in the thermally induced evolution of the deposited films.
Why is Dawsonite Absent in CO2 Charged Reservoirs

Growth of the sodiumaluminium-hydroxy carbonate dawsonite (NaAl(OH)2 CO3 ) after charging saline aquifers with CO2 has been assumed in a plethora of numerical simulations at different mineralogies, aqueous solutions, pressures and temperatures. It appears however that dawsonite is less abundant than expected in natural CO2 storage analogues if we take into account the thermodynamic stability alone. We have mapped the thermodynamic stability of dawsonite relative to mineral phases like albite, kaolinite and analcime from 37° to 200°C and performed closed-system batch kinetic simulations using a new kinetic expression including a nucleation term based on classical nucleation theory, and a growth term that was based on BCF growth theory. Using this rate equation, we have performed a sensitivity study on dawsonite growth on mineralogy, temperature, CO2 pressure, nucleation rate and its dependencies on temperature and affinity, and on the dawsonite precipitation rate coefficient. Simulations with dawsonite growth disabled showed that the maximum oversaturation reached for dawsonite for seawater-like solutions never exceeded 3-4 times oversaturation. The positive effect on dawsonite growth of increasing the CO2 pressure was mostly neutralized by higher acidity. Decreasing the precipitation rate coefficient by 5 orders of magnitude had a limited effect on the onset of significant growth, but the amount of dawsonite formed at the end of the 1 000 years simulated time was only 37% below the high-rate case. Reducing the nucleation rates had similar effects leading to postponed dawsonite growth. Finally, based on thermodynamic considerations and numerical simulations, we suggest that the potential of dawsonite growth is limited to a medium-temperature window framed by a high thermodynamic stability relative to competing mineral phases at low temperatures, but with rapidly diminishing nucleation and growth rates at lower temperatures constrained by energy barriers.