Miracle-dz/UniFAR-FTUs huggingface dataset:
Online Measurements of Individual Alkali-Containing Particles Formed in Biomass and Coal Combustion: Demonstration of an Instrument Based on Surface Ionization Technique

Online measurements of individual alkali-containing submicrometer particles in a circulating fluidized bed (CFB) combustion facility are presented. A recently developed particle beam mass spectrometer based on surface ionization technique is demonstrated and its performance during a field campaign in a 12 MW CFB reactor operating under atmospheric conditions is discussed. The boiler was fired with a biomass fuel consisting of a mixture of wood chips and pellets. During part of the campaign K 2 CO 3 , HCl, and SO 2 were also added to the fuel to investigate their influence on alkali-related processes. Size-selected particles with diameters of 50-300 nm in general had high potassium content, while sodium, rubidium, and cesium were present as minor constituents. Particles formed by recondensation of compounds evaporated during the combustion process could be distinguished from fly ash particles on the basis of their potassium and sodium contents. The number of alkali-containing particles increased when the K, Cl, and S fluxes into the boiler increased, and the trend was confirmed by independent measurements of the total particle concentrations in the flue gas. The concentration of potassium bound to submicrometer particles was found to be in the range 0.8-13 mg/m 3 under the studied operating conditions. When the facility was instead fired with bituminous coal as a fuel, the relative concentration of sodium compared with potassium was higher, and a larger fraction of the alkali compounds were found in fly ash particles. The particle beam mass spectrometer is concluded to accurately provide online information on particle-bound alkali concentrations under the conditions typically prevailing at a commercial-size boiler, and the possibilities for future research and technical development are discussed.
Effect of infrared radiation on the drying kinetics of osmosed papaya cubes

In osmotic dehydration, papaya cubes were immersed in the sugar syrup having concentration 60%, constant temperature 37oC and immersion time 4.25 h. A laboratory scale infrared- convective dryer was used for drying osmosed papaya cubes. The drying was carried out at infrared power levels of 300, 400 and 500 W, drying air temperature of 40, 50 and 60oC and air velocities of 1.0, 1.5 and 2.0 m/s. The infrared convective drying of osmosed papaya cubes exhibited drying having taken place in falling drying rate period. The drying rate was significantly influenced by infrared power, air temperature and air velocity. The drying time increased with increased in air velocity at all infrared power and air temperature.
Study of Chemical Structure Changes of Chinese Lignite upon Drying in Superheated Steam, Microwave, and Hot Air

Chemical changes of Chinese lignite upon drying in superheated steam, microwave, and hot air have been studied in this paper using the Fourier transform infrared (FTIR) spectroscopy technique. The infrared (IR) spectra of raw and dried samples were curve-fitted to a series of bands in aliphatic hydrogen (3000–2800 cm–1) and carbonyl absorption (1850–1500 cm–1) zones. It has been found that aliphatic hydrogen absorbance decreased slightly with an increasing temperature during superheated steam drying, while absorption of carboxyl (COOH) and carbonyl (C═O) groups decreased drastically, indicative of the loss of oxygen functionalities with an increasing drying temperature. During steam drying, aromatic carbon and aromatic ring stretch absorption remained relatively unchanged up to 250 °C and decreased significantly thereafter because of some pyrolysis reactions that took place at higher drying temperatures. Microwave heating of lignite resulted in a significant decrease in the concentration of oxygen-contain.
Effects of Anions on the Formation of Aluminosilicate Gel in Geopolymers

This work demonstrates that an increase in soluble silicate concentration over ∼200 mM in an aqueous alkaline solution (pH = ∼13.95) can significantly increase the reactivity of a Class F fly ash at room temperature. The greatly increased dissolution of the fly ash primary phase(s) and the subsequent secondary precipitation are responsible for the formation of an aluminosilicate gel similar to the major binding phase of a geopolymer. On the basis of this observation, a reaction model was developed to simulate aluminosilicate gel formation in a real geopolymeric system. In this work, potassium salts of chloride, carbonate, oxalate, and phosphate (KCl, K2CO3, K2C2O4·H2O, and K2HPO4) were used as solution contaminants. It was found that the anions (Cl-, CO32-, C2O42-, and PO43-) significantly affected the formation kinetics as well as the nature of the aluminosilicate gel formed in the reaction model. This observation could be successfully used to mechanistically explain the retardation effects of the variou.
High precision calcium isotope ratio measurements using a magnetic sector multiple collector inductively coupled plasma mass spectrometer

Calcium isotope abundances were measured using a Finnigan Neptune magnetic sector multiple collector inductively coupled plasma mass spectrometer capable of resolving all molecular isobaric interferences from 42Ca, 43Ca, 44Ca, 46Ca and 48Ca. Scattering events caused by the intense 40Ar+ ion beam did not contribute to the uncertainty in the baseline of the calcium mass spectrum. Quantitative separation of the calcium from the sample matrix was carried out to ensure that the measurements were independent of the sample type. In addition, thorough desolvation of the aerosol was found to have a significant effect on the stability and sensitivity of the method. The stable mass bias of the instrument enabled normalization of the measured isotope abundance ratios relative to standard reference materials. Delta values including δ44Ca/43Ca, δ44Ca/42Ca and δ48Ca/42Ca were measured with external reproducibilities better than ±0.2‰ (2s) from 10 ppm solutions of calcium-containing materials, including sea-water and biogenic and non-biogenic marine carbonates.
Adsorción de arsénico en zeolita natural pretratada con óxidos de magnesio

A methodology was developed to modify a natural zeolite (chabazite) with magnesium oxide in order to remove arsenic (As +5 ) from water for human consumption. It is proposed a magnesium oxide while regarded as an efficient adsorbent for removing metals in water. X-ray diffraction analyses show significant changes in the chabazite due to the presence of oxides and amorphous hydroxides incorporated during the pretreatment. Experimental design results show an efficiency greater than 90 % of As +5 adsorbed in five minutes. The results indicate that the most significant variables affecting the adsorption of As +5 are the initial concentration of As and the solid/liquid (S/L) ratio. Experimental data fitted better to Freundlich isotherm with a 20.17 mg/g adsorption capability.
Potassium reserves in a forested, acid upland soil and the effect on them of clear-felling versus whole-tree harvesting.

The experiment conducted jointly by the Forestry Commission (FC) and the Institute of Terrestrial Ecology (ITE) at Beddgelert Forest, North Wales, studies the effect of conventional clear-felling (CF) and whole-tree harvesting (WTH) of Sitka spruce (Picea sitchensis) on the local ecosystem and on the future productivity of forestry at the site. Bulked soil samples were taken from Block 2 of the experiment just before felling in 1984 and two years later in 1986. Sub-samples from the horizons Ah, E and B+C were analysed for exchangeable and short- and long-term reserves of K using Ca-resin and strong acid extraction procedures. The flux of K through the soil profile after both CF and WTH resulted in a small increase in exchangeable K throughout the profile after both treatments, but in a loss of short-term reserves from the surface Ah horizons of both and an overall loss of these after WTH. The nutrient flux down-slope through the Ah horizon could result in differential nutrient deficiency in future. The data suggest that exchangeable and short-term reserves of K will support about two further cycles of conifers, with either CF or WTH, but that long-term reserves are likely to be released quickly enough to meet the needs of such a slow-growing crop; these would support about 30 cycles. Other nutrients, such as Ca or P, may prove to be more limiting than K.
Investigation of structural stability and electronic properties of group III nitrides: a first principles study

The high-pressure structural phase transition, electronic, superconducting and elastic properties of group III nitrides (ScN, YN and LaN) are investigated by first principles calculation with the density functional theory. The calculated lattice parameters are in good agreement with the experimental and other theoretical values. Electronic structure reveals that these materials are semiconductors with an indirect band gap of 1.4, 0.87 and 0.65 eV for ScN, YN and LaN, respectively. The obtained cubic NaCl structure is energetically the most stable structure at ambient pressure. A pressure-induced structural phase transition from NaCl to CsCl structure is predicted. The structural phase transition of ScN, YN and LaN occurs at a pressure of 158, 132 and 26.5 GPa, respectively. On further increase in the pressure, semiconductor-to-metallic transition and superconductivity is observed in these nitrides. The estimated T c values as a function of pressure for ScN, YN and LaN are 31.79, 15.50 and 12.84 K, respectively.
N-[(3-Methyl-5-oxo-1-phenyl-4,5-di­hydro-1H-pyrazol-4-yl­idene)(phenyl)­methyl]­glycine ethyl ester

In the title compound, C21H21N3O3, the pyrazolone and the N atom of the glycine ethyl ester group are essentially coplanar. The compound is a neutral tridentate ligand in an en­amine–keto form, stabilized by two strong intramolecular N—H⋯O hydrogen bonds.
Phosphorus fractionation in biosolids-amended soils: relationship to soluble and desorbable phosphorus.

Phosphorus has been identified as a major factor involved in decreasing water quality through its role in eutrophication, and there is now a focus on controlling nonpoint agricultural P sources. This work was conducted to identify how biosolids applications under current regulations have affected the forms and release potential of P in agricultural soils. We collected samples from eight farms with a history of biosolids amendments, selecting fields that had setback areas (where biosolids applications were not permitted) to allow comparison of amended and unamended soils. We analyzed these soils for P fractions (soluble P, Al-P, Fe-P, reductant soluble P, and Ca-P; their sum equals total P), sequentially desorbable P (Fe-strip), oxalate P, Al and Fe, Mehlich-1 P, and the degree of P saturation. Our results show that following a N-based biosolids nutrient management plan can significantly increase total P (from 403 to 738 mg kg -1 ) and initially desorbable P (from 32 to 61 mg kg -1 ). The main soil components associated with P retention (Al 0x and Fe 0x ) also tended to be increased by biosolids amendment and this may help mitigate P release. Biosolids amendment significantly increased Fe-P (from 137 to 311 mg kg -1 ), probably due to Fe added to biosolids during production, and there was also a strong trend for higher Al-P where biosolids had been applied. Desorbable P was initially greatest from biosolids sites, but with increasing extractions, the release converged towards that from the setback areas. Mehlich-1 P and P ox , were good predictors of desorbable P release, as measured by one and five sequential extractions with Fe-strips. Desorbable P, by both one and five Fe-strip extractions, was more closely correlated with Al-P than Fe-P, especially in setback areas, indicating that Al-P is probably the most important source of desorbable P independent of biosolids amendment. This work indicates the importance of considering P availability at agricultural biosolids application sites and of maintaining setback areas near water bodies, where no biosolids may be applied, to reduce the risk of P losses.
Removal of near-interface traps at SiO2/4H–SiC (0001) interfaces by phosphorus incorporation

Effective removal of near-interface traps (NITs) in SiO2/4H–SiC (0001) structures through phosphorus incorporation is demonstrated in this paper. Low-temperature capacitance-voltage and thermal dielectric relaxation current measurements were employed to investigate NITs in oxides prepared by dry oxidation, NO annealing, and POCl3 annealing. Both the measurements revealed that the density of electrons trapped in NITs in POCl3-annealed oxide is smaller than that in dry and NO-annealed oxides. The drastic elimination of NITs lowers the interface state density and increases the channel mobility in 4H–SiC metal-oxide-semiconductor field-effect transistors.
Metallic Nanostructure Formation Using Self-Assembled Chemically Anchored Gold Nanoparticles

In the present work, the formation of silver nano- and mesopourous structures on highly oriented pyrolytic graphite (HOPG) modified with self-assembled gold nanoparticles (Au NPs) is demonstrated. To illustrate the patterning effect with nanometer resolution of Au NPs, a comparison between silver electrodeposition on bare HOPG (0001) substrate and Au NP-modified HOPG (0001) surface is performed. On bare HOPG substrate the electrodeposition occurs on terraces, steps, and surface defects according to the well known Volmer-Weber island growth mechanism. Whereas on the Au NP-modified HOPG substrate, silver deposition results in a very different morphology: nanostructures (mesoporous films for longer deposition time) are formed on the entire electrode surface. Field emission gun scanning electron microscopy, energy dispersive spectrometry and X-ray photoelectron spectroscopy are used to reveal the selective deposition of silver on Au NPs during the first stage of the electrodeposition process. At the later stage due to coalescence, mesoporous silver film is formed. The possible mechanism for silver ions penetration and reduction on single Au NP with n-dodecanethiol shell is discussed.
Soil Fertility Status and Disorders in Arecanut (Areca Catechu L.) Grown on Clay and Laterite Soils of India

In arecanut, disorders like crown choking and crown bending lead to death of palms within a short span. Spatial and temporal variability in soil and leaf nutrient status was used as a tool to find out the causes for disorders in clay and laterite soils. Availability of nutrients in soils was sufficient to excess. Deviation from optimum percentage index was negative for nitrogen (N), phosphorus (P), and zinc (Zn) in both soils. Zinc deficits of –26 to –63 in higher number of palms (84–97%) indicate the reduction in Zn uptake. Regression between leaf Zn and soil fertility parameters indicated negative relation with soil Zn and calcium (Ca) in clay and soil organic carbon, soil P, and soil boron (B) in laterite soils. Multiple regression indicated negative relation of diethylenetriaminepentaacetic acid (DTPA)-extractable Zn with nutrients like Ca, magnesium (Mg), potassium (K), and iron (Fe) in soil in different years. The grouping of soil nutrients in opposite directions in first two components of principal component analysis supports negative nutrient interactions in both soil types. The results reveal that nutrient interactions in soil affect the uptake of nutrients despite sufficient nutrient availability. Zinc deficiency in arecanut may be the result of complex interactions between DTPA-extractable Zn and other nutrients in soil.
Liquid−Liquid Equilibrium of Aqueous Two-Phase Systems Containing Some Synthetic Polyelectrolytes and Polyethylene Glycol†

Experimental results are presented for the liquid−liquid equilibrium of aqueous two-phase systems containing a synthetic polyelectrolyte (polysodium acrylate, polysodium methacrylate, and polysodium ethylene sulfonate) and polyethylene glycol at (298.2 and 323.2) K. A total of 40 phase diagrams were obtained, comprising data both of the binodal curve (obtained through cloud-point measurements) and of equilibrium compositions. The influences of temperature, the nature of the polyelectrolyte monomer unit, and the chain length of both types of polymers are analyzed and discussed.
Defect structure of Pb-doped Bi2Te3 single crystals

Pb-doped Bi2Te3 single crystals with a Pb concentration of c Pb = 0−9.4 × 1025 m−3 were prepared from the elements Bi, Pb and Te of 99.999% purity by means of the Bridgman method. Samples of these crystals were characterized by measurements of the Hall coefficient R H(B∥c), electrical conductivity σ⊥c and Seebeck coefficient α(c⊥ΔT) over the temperature range 90–420 K. It was found that Pb impurities in Bi2Te3 behave as acceptors; some (40%) of the incorporated Pb atoms are electrically inactive. This effect is explained by the model of crystal lattice defects based on the assumption that the Pb atoms interact with native defects in the crystal lattice of undoped Bi2Te3, that is with antisite defects and vacancies in the Te sublattice.
Comparative Crystallography. 5. Crystal Structures, Electronic Properties, and Structural Pathways of Five [Cu(phen)2Br][Y] Complexes, Y = [Br]-·H2O, [ClO4]-, [NO3]-·H2O, [PF6]-, and [BPh4]-

The crystal structures of [Cu(phen)2Br][Br]·H2O (1, phen = 1,10-phenanthroline), [Cu(phen)2Br][ClO4] (2), [Cu(phen)2Br][NO3]·H2O (3), [Cu(phen)2Br][PF6] (4), and [Cu(phen)2Br][BPh4] (5) have been determined by X-ray diffraction. Four of the complexes, 1−4, have a CuN4Br chromophore with a square based pyramidal distorted trigonal bipyramidal (SBPDTB) stereochemistry, while 5 involves an extreme trigonal bipyramidal distorted square based pyramidal (TBDSBP) stereochemistry. The geometries of the CuN4Br chromophores in 1−5 are compared by scatter plot analysis with a single [Cu(phen)2Br][ClO4] complex, 6, of known crystal structure involving a crystallographic 2-fold axis of symmetry. The distortion isomers of 2 and 6 are significantly different. The scatter plots of the six cation distortion isomers of the [Cu(phen)2Br][Y] series of complexes suggest that all six complexes lie on a common structural pathway, involving a mixture of the symmetric, νsym, C2 mode and the asymmetric, νasym, non-C2 mode of vibra.
Oxygen transfer in a model hydrocarbon bioprocess in a bubble column reactor

The expansion of the global fuels industry has caused an increase in the quantity of hydrocarbons produced as a by-product of refinery gas-to-liquid processes. Conversion of hydrocarbons to higher value products is possible using bioprocesses, which are sustainable and environmentally benign. Due to the deficiency of oxygen in the alkane molecule, the supply of sufficient oxygen through aeration is a major obstacle for the optimization of hydrocarbon bioprocesses. While the oxygen solubility is increased in the presence of hydrocarbons, under certain process conditions, the enhanced solubility is outweighed by an increase in viscosity, causing a depression in overall volumetric oxygen transfer coefficient (KLa). The rate at which oxygen is transferred is defined in terms of a concentration driving force (oxygen solubility) and the overall volumetric oxygen transfer coefficient (KLa). The KLa term comprises an oxygen transfer coefficient (KL) and the gas-liquid interfacial area (a), which are dependent on the fluid properties and system hydrodynamics. This behaviour is not well understood for hydrocarbon bioprocesses and in a bubble column reactor (BCR). To provide an understanding of oxygen transfer behaviour, a model hydrocarbon bioprocess was developed using a BCR with a porous sparger. To evaluate the interfacial area, the Sauter mean bubble diameter (D32) was measured using an image analysis algorithm and gas holdup ( G) was measured by the change in liquid height in the column. Together the D32 and G were used in the calculation of interfacial area in the column. The KLa was evaluated with incorporation of the probe response lag, allowing more accurate representation of the KLa behaviour. The probe response lag was measured at all experimental conditions to ensure accuracy and reliability of data. The model hydrocarbon bioprocess employed C14−20 alkane-aqueous dispersions (2.5 20 vol% hydrocarbon) with suspended solids (0.5 6 g/l) at discrete superficial gas velocity (uG) (1 3 cm/s). For systems with inert solids (corn flour, dp = 13.36 μm), the interfacial area and KLa were measured and the behaviour of KLa was described by separation of the influences of interfacial area and oxygen transfer coefficient (KL). To further the understanding of oxygen transfer behaviour, non-viable yeast cells (dp = 5.059 μm) were used as the dispersed solid phase and interfacial area behaviour was determined. This interfacial area behaviour was compared with the behaviour of systems with inert solids to understand the differences with change in solids type. In systems using inert solids, a linear relationship was found between G and uG. An empirical correlation fo rthe prediction of this behaviour showed an accuracy of 83.34% across the experimental range. The interfacial area showed a similar Stellenbosch University https://scholar.sun.ac.za
Consumer discrimination of Chemlali and Arbequina olive oil cultivars according to their cultivar, geographical origin, and processing system

The chemical composition and consumer preferences according to consumer characteristics of virgin olive oils (VOOs) from “Chemlali” and “Arbequina” cultivars were studied in relation to processing system and geographical origin. Statistical analyses revealed significant differences (p < 0.05) among cultivars in % free acidity, K270, and OSI values, pigments, and antioxidant content and in some FAME content. Significant differences were also found according to the processing system in terms of some quality indices, pigments, antioxidant compounds, and OSI values. The effect of processing system on fatty acid composition was almost not significant except for some of them. The effect of the geographical origin was different in relation to the cultivars: For “Chemlali” cultivar, it was significant (p < 0.05) in all studied parameters except for acidity and total polar phenol content. However, for “Arbequina”, the effect was significant (p < 0.05) for K232, pigments, antioxidant compounds and fatty acid composition except for margaric, margaroleic, linolenic, arachidic, and behenic fatty acids. Consumers were able to discriminate between cultivars with more preference for “Arbequina” oil, but only in case of “Chemlali” they could discriminate between the oils from different locations, with significantly more consumer liking for oils from Sidi Bouzid and Sawef. However, they were not able to discriminate between the processing systems. A session of sensory analysis that shows consumer preferences according to consumer characteristics. Consumer preferences are defined as the subjective (individual) tastes and flavors, as measured by the satisfaction that a consumer derives from the consumption of different goods, in this study, the Virgin Olive Oil (VOO). VOO sensory analysis permits the consumer to rank the different oils according to the levels of satisfaction they give the consumer.