Miracle-dz/UniFAR-FTUs huggingface dataset:
Caracterização físico-química de variedades de amora-preta da região sul do Brasil

Blackberry (Rubus sp.) is a fruit whose commercial exploitation is starting in Brazil. Its cultivation began in the 70's and is increasing with the introduction and adaptation of new cultivars. However, little is known about the disparities in the composition and characteristics of the fruit from these new plants. The objective of this study was to evaluate the physicochemical characteristics of different cultivars ('Tupy', 'Guarani' and 'Cherokee') and selections (02/96, 07/001 and 03/001) of blackberries, which are being studied to generate cultivars adapted to Southern Region of Brazil. The objective color, soluble solids (SS), pH, titratable acidity, proximate composition and fatty acids of blackberries were evaluated. The fruit humidity ranged between 84.8 and 90.3%; protein between 0.09 and 0.14%, dietary fiber between 5.5 and 5.8% and ash between 0.27 and 0.49%. Selection 02/96 had the lowest ash content. SS ranged from 7.3 to 10.2°Brix, titratable acidity ranged between 1.30 and 1.58% citric acid and pH between 2.8 and 3.1. Selection 03/001 had the lowest SS value and it also had lower redness, but higher color saturation than 'Tupy' cultivar. The fatty acids found at higher concentration were palmitic (22-29%), oleic (13-32%) and linoleic acid (15-33%), with differences in the concentration among blackberry genotypes. The varieties of blackberry evaluated showed good nutritional value with sugar and acidity levels suitable for industrialization. It also contained fatty acids important for maintaining health.
Tamanho ótimo de parcela para avaliação do rendimento de grãos do girassol

The aim of this study was to determine the appropriate size of plot for evaluation of grain yield of sunflower. An experiment in randomized complete block design with 14 cultivars of sunflower and 10 replications was conducted in the period of May to July 2011. The plots consisted of four rows of 6 m in length, spaced 0.7 m and 0.3 m between plants. The useful area of the plot, consisting of the two central rows was divided into 12 basic units (UBs), each consisting of three plants in the row, the yield of sunflower per basic unit was determined. Grain yield of adjacent UBs were grouped to form 7 types of plots of five different pre-established sizes. The optimum plot size was estimated by the methods of modified maximum curvature (3.74 m2) and the segmented linear model with plateau (2.48 m2), with the size of 3.74 m2 of floor area considered suitable for assessment of grain yield of sunflower and less than the size generally used in research with sunflower.
Predicting the incidence of iron chlorosis in calcareous soils of Southern Spain

Abstract Iron chlorosis is a serious crop production problem in many calcareous soils of Southern Spain. The objective of this study was to determine which indigenous soil properties (i.e., those which are essentially permanent) were related to Fe chlorosis. Experiments, using two chickpea (Cicer ariethinum L.) cultivars and a sunflower (Helianthus annuuus L.) cultivar, were carried out in a growth chamber with 25 calcareous soils representing widespread Xerofluvents, Xerorthents, Xerochrepts, Haploxeralfs, Rodoxeralfs, Chromoxererts, and Pelloxererts of Southern Spain. The average chlorophyll contents for the three cultivars were significantly correlated with several properties of the carbonate and Fe oxide phases, such as calcium carbonate equivalent (r = 0.69∗∗∗), “active lime”; (r = 0.58∗∗), acid NH4‐oxalate extractable Fe (r = 0.68∗∗∗), Tiron‐extractable Fe (r = 0.61∗∗), and DTPA‐extractable Fe (r = 0.55∗∗). The present and other studies indicate that the soil property most consistently related to Fe.
Moisture Sorption Hysteresis in Kudzu Starch and Sweet Potato Starch

Moisture sorption hysteresis loops of kudzu starch and sweet potato starch were investigated to help understand the nature of the adsorption-desorption process. The second adsorption isotherms were above the first adsorption isotherms for kudzu starch and sweet potato starch preheated to 110°C. This was explained as an increase in the number of hydrophilic sites due to rupturing of hydrogen bonds. The hysteresis loop for kudzu starch was greater than that for sweet potato starch. This was interpreted as a difference in mesopore volume.
In-Vivo Evaluation of Different Types of Commercial Aspirin Tablets

AbstractIn-vivo evaluation of four different types of aspirin tablets namely effervescent, soluble, buffered and aluminium derivative of aspirin was assessed in six healthy subjects. The bioavailability parameters of the studied aspirin types were calculated. Effervescent aspirin showed the best results, while buffered aspirin showed the worst.The pharmacokinetic parameters of the six subjects for the different types of aspirin tablets were also computed. Out of all the different types of aspirin tablets studied, effervescent aspirin exhibited the highest absorption rate constant, while aluminium derivative of aspirin showed the lowest absorption rate constant. Sex was found to greatly affect the absorption of aspirin from the different types of tablets studied, where in all cases male subjects gave higher absorption rate constants and greater bioavail ability parameters than females.
Chemical and optical properties of small metal particles in aqueous solution

Although colloidal metals are systems with a huge amount of interface, relatively few surface chemistry studies of these systems have been made. A number of surface reactions on metallic silver particles (4-nm diameter) are described in the present article and the accompanying changes in the optical properties are discussed. The reactions include the deposition of excess electrons and positive holes, changes in the Fermi level position and reactivity upon adsorption of various molecules, and photochemical reactions. The preparation and properties of oligomeric silver clusters in aqueous solution are also described. The clusters have strong absorption bands, undergo electron transfer with many acceptors, photoemit electrons with large quantum yields, and react eagerly with nucleophiles. The cluster Ag42+, a special form of dimeric silver, is stable towards oxygen, whereas larger clusters are readily oxidized. The chemical changes associated with the colloid atom transition are demonstrated by discussing various properties such as the electrochemical potential of silver aggregates as a function of size. Cluster formation in the reduction of other metals (Pd, Cu, Au, Pb) in aqueous solution is also discussed briefly.
Speciation of phytate ion in aqueous solution. Non covalent interactions with biogenic polyamines

Abstract The noncovalent interactions of phytate (Phy6-) with biogenic amines were studied potentiometrically in aqueous solution, at t= 25°C. Several species are formed in the different H+-Phy6--amine (A) systems, which have the general formula Ap(Phy)Hq(12-q)-, with p ≤ 3 and 6 ≤ q ≤ 10. The stability of these species is strictly dependent on the charges involved in the formation equilibria. For the equilibrium pHiAi+ + Hj(Phy)(12-j)- = Ap(Phy)Hq(12q)-, (q = pi + j)we found the relationship logK= aζ (ζ is the charge product of reactants), where a= 0.35(0.03, valid for all the amines; this roughly indicates an average free energy contribution per bond -ΔG0 = 4.0 ± 0.2 kJ mol-1. A slightly more sophisticated equation is also proposed for predicting the stability of these species. Owing to the quite high (partially protonated) phytate charge, the stability of Ap(Phy)Hq(12-q)- species is quite high, making phytate a strong amine sequestering agent in a wide pH range.
Modeling and Simulation of Moving Bed Reactor for Catalytic Naphtha Reforming

Abstract A lumped kinetic model for catalytic naphtha reforming with 27 lumps is developed in order to predict aromatic compositions in more detail. The 8-carbon aromatics are subdivided into ethylbenzene and xylene, and 9-carbon aromatics are subdivided into trimethylbenzene, methylethylbenzene, and propylbenzene, respectively. The simulation of a Universal Oil Products (UOP) commercial continuous reforming unit is carried out to validate the model. The results show that perfect agreement of compositions at the exit of the fourth reactor is obtained between simulated values and reported values and the mass contents of benzene, toluene, ethylbenzene, xylene, trimethylbenzene, methylethylbenzene, and propylbenzene are predicted accurately. The calculated temperature at the exit of each reactor is consistent with the actual value. The composition and temperature profiles are calculated, and the two-dimensional distributions of coke content of catalyst bed are simulated.
Selective Oxidation of Hydrocarbons with O2 over Chromium Aluminophosphate-5 Molecular-Sieve

Chromium-substituted aluminophosphate-5 (CrAPO-5) is a heterogeneous, recyclable catalyst for the liquid phase autoxidation of hydrocarbons. CrAPO-5 catalyzed the autoxidation of cyclohexane at 115-130°C and 5 bar O2, 20 bar air in the presence of a small amount of an alkyl hydroperoxide initiator, to afford cyclohexanone as the major product. Similarly, tetralin and indane were selectively oxidized to 1-tetralone and 1-indanone, respectively, at 100°C and 1 bar O2. Ethylbenzene was selectively converted to acetophenone, in the presence of sodium-exchanged CrAPO-5, at 130°C and 1 bar O2. The CrAPO-5 catalyst was recycled four times without loss of activity or selectivity in the decomposition of cyclohexyl hydroperoxide. Evidence is presented to support a mechanism involving initial free radical autoxidation of the hydrocarbons followed by selective CrAPO-5-catalyzed intramolecular, heterolytic decomposition of the secondary alkyl hydroperoxide intermediate to the corresponding ketone and water.
Laser beam induced current imaging of surface nonuniformity at the HgCdTe/ZnS interface

Laser beam induced current has been utilized to obtain maps of the electrical nonuniformities at the ZnS‐passivated liquid phase epitaxy HgCdTe surface under a metal–insulator–semiconductor (MIS) capacitor. Features are observed that are not indicated in the C–V profile for the MIS structure. This technique represents a convenient way of spatially mapping the electrical characteristics of semiconductor surfaces and offers the potential for assessing and optimizing the quality and uniformity of the passivating layer.
CHEMISTRY, PROPERTIES, AND PHYLOGENETIC IMPLICATIONS OF THE METHYLATED CARRAGEENANS FROM RED ALGAE OF THE GENUS ARESCHOUGIA (ARESCHOUGIACEAE, GIGARTINALES, RHODOPHYTA)

The three Australian‐endemic species comprising the genus Areschougia have been examined to determine the structure of their nonfibrillar wall components. The polysaccharide extracted from the most widely distributed species, A. congesta (Turner) J. Agardh, was shown by compositional analyses, Fourier transform infrared (FTIR) spectroscopy, linkage analysis, and 13C‐NMR spectroscopy to be a carrageenan composed predominantly of the repeating disaccharides 6′‐O‐meth‐ ylcarrabiose 2,4′‐disulfate, carrabiose 2,4′‐disulfate (the repeating unit of ι‐carrageenan), 4′,6′‐O‐(1‐carboxyethylidene)carrabiose 2‐sulfate, and 6′‐O‐methylcarrabiose 2‐sulfate. The carrageenan also contained small amounts of 4‐linked Galp residues, some bearing methyl ether substitution at O‐3 and some possibly bearing sulfate ester and/or glycosyl substitutions at O‐3. The A. congesta carrageenan had unique rheological properties, its gels having some similarities to those of commercial ι‐carrageenan but with the viscosity of commercial λ‐carrageenan. Polysaccharides from A. ligulata Harvey ex J. Agardh and A. stuartii Harvey were shown by constituent sugar and FTIR analyses to be sulfated galactans rich in mono‐O‐methylgalactose. The carrageenan structures of Areschougia spp. were consistent with those of the genera Rhabdonia, Erythroclonium, and Austroclonium, the other genera constituting the family Areschougiaceae.
Structure of sesquiterpenic lactones of some species of subtribe Centaureinae dumort

The authors describe in full the elucidation of complete structures of guaianolide and germacranolide lactones, isolated from some species of genera Centaurea L. , Chartolepis CASS. and others belonging to subtribe Centaureinae DUMORT. The structures were determined mainly on the basis of detailed analysis of 1 H NMR and CD spectra. The structure of linichlorin B ( XV ) was determined by X-ray diffraction analysis.
Tautomerism in Schiff bases derived from 3-hydroxysalicylaldehyde. Combined X-ray diffraction, solution and solid state NMR study

The crystal structure of six Schiff bases derived from 3-hydroxysalicylaldehyde has been determined by single crystal X-ray diffraction. In the solid state, these compounds form dimers linked by two strong intermolecular O–H⋯O bridges resulting in ten-membered pseudocycles. From the observed geometrical parameters together with previous results obtained for N-(3-hydroxysalicylidene)isopropylamine, it can be concluded that these compounds undergo a fast proton exchange between two forms, phenol–imine and keto-amine. The tautomeric equilibrium mixture is greatly influenced by the physical state of the examined compounds. This is clearly seen when comparing results obtained from liquid and solid-state 13C NMR. For derivatives derived from aliphatic amines the keto-amine tautomer is always predominant; for compounds obtained from substituted anilines the tautomeric concentration is variable depending on the nature of the substituent. An excellent correlation between C–O bond lengths and 13C chemical shifts is observed.
A THERMODYNAMIC MODEL TO PREDICT WAX FORMATION IN PETROLEUM FLUIDS

Some years ago the authors proposed a model for the non-ideality of the solid phase, based on the Predictive Local Composition concept. This was first applied to the Wilson equation and latter extended to NRTL and UNIQUAC models. Predictive UNIQUAC proved to be extraordinarily successful in predicting the behaviour of both model and real hydrocarbon fluids at low temperatures. This work illustrates the ability of Predictive UNIQUAC in the description of the low temperature behaviour of petroleum fluids. It will be shown that using Predictive UNIQUAC in the description of the solid phase non-ideality a complete prediction of the low temperature behaviour of synthetic paraffin solutions, fuels and crude oils is achieved. The composition of both liquid and solid phases, the amount of crystals formed and the cloud points are predicted within the accuracy of the experimental data. The extension of Predictive UNIQUAC to high pressures, by coupling it with an EOS/GE model based on the SRK EOS used with the LCVM mixing rule, is proposed and predictions of phase envelopes for live oils are compared with experimental data.
One-step synthesis of solid sulfonic acid catalyst and its application in the acetalization of glycerol: crystal structure of cis-5-hydroxy-2-phenyl-1,3-dioxane trimer

A one-pot method was employed to immobilize sulfonic acid onto silica obtained from rice husk ash using 3-(mercaptopropyl)trimethoxysilane to form a solid catalyst denoted as RHASO3H. BET measurements of the catalyst showed the surface area to be 340 m2 g−1 with the average pore volume of 0.24 mL g−1 and the pore diameter of 2.9 nm. Acidity test of cation exchange capacity and pyridine adsorption studies revealed the presence of Brønsted acid sites on the catalyst surface. The catalyst was used in the acetalization reaction of glycerol with benzaldehyde. Under optimized conditions, the reaction showed the maximum conversion of 78 % after 8 h with 67 % selectivity towards the five membered ring isomer. Variation in the glycerol concentration had a significant effect on the reactants conversion. A single crystal X-ray study of one of the products proved the existence of a unique trimer formed by hydrogen bonding by the six-membered cis-isomer. The catalyst was several times recycled without any loss of its catalytic activity.
Adsorptive removal of fluoride from water using nanoscale aluminium oxide hydroxide (AlOOH)

In this study the fluoride removal potential of nanoscale aluminium oxide hydroxide (nano-AlOOH) has been investigated. The material was produced using aluminium nitrate (Al(NO 3 ) 3 . 9H 2 O, 95%), and ammonium bicarbonate (NH 4 HCO 3 , 98%) and its density and mineralogy were investigated. A series of batch adsorption experiments were carried out to assess parameters that influence the adsorption process. The parameters considered were contact time and adsorbent dose, initial fluoride concentration, and pH. Results showed that most of the adsorption took place during the first 30 min; and equilibrium was reached at one hour contact time with an optimum adsorbent dose of 1.6 g L -1 for initial fluorideconcentration of 20 mg L -1 . The removal efficiency of fluorideincreased with increase in adsorbent dosage. The fluoride removal efficiency was increased as the pH of the solution increases from pH 3 to 8, but any further increase in pH led to a decrease in fluoride removal efficiency. Maximum adsorption occurred at around pH 7 with initial fluoride concentration of 20 mg L -1 . The adsorption data were well fitted to the Langmuir isotherm model with a maximum adsorption capacity of 62.5 mg F - g -1 . The kinetic studies showed that the adsorption of fluoride by nano-AlOOH obeys a pseudo-second order rate equation. The intraparticle diffusion was not a rate-controlling step for the adsorption process. Thus, the overall study indicates that nano-AlOOH is an efficient defluoridating material. KEY WORDS : Nanoscale AlOOH, Defluoridation, Fluoride removal efficiency, Adsorption capacity, Adsorption kinetics, Adsorption mechanism Bull. Chem. Soc. Ethiop. 2014 , 28(2), 215-227. DOI: http://dx.doi. org/10.4314/bcse.v28i2. 6
High-current long-duration uniform electron beam generation in a diode with multicapillary carbon-epoxy cathode

The results of reproducibly generating an electron beam with a current density of up to 5 kA/cm2, without the cathode-anode gap being shorted by the plasma formed inside the cathode carbon-epoxy capillaries, in a ∼350 kV, ∼600 ns diode, with and without an external guiding magnetic field, are presented. The cathode sustained hundreds of pulses without degradation of its emission properties. Time- and space-resolved emissions of the plasma and spectroscopy analyses were used to determine the cathode plasma's density, temperature, and expansion velocity.
Photodegradative wavelength dependence of thermally resistant organic polymers

The wavelength dependence of photodegradation of three “high temperature” aromatic polyamide polymers has been very accurately determined by means of a fast grating spectrograph used in conjunction with a high pressure xenon arc. One of these polymers, the poly-(isophthalamide) of 4,4′-bis(p-aminophenyl)-2,2′bithiazole, was found to be degraded significantly by visible light, especially that of 4140 A, wavelength. Both the poly-terephthalamide of 1,3-bis(3-aminobenzamide) benzene and Du Pont Nomex, also an aromatic polyamide, were damaged primarily by radiation in the near ultraviolet region. Degradation band maxima for these polymers were observed at 3700 A, and 3600 A, respectively. All three thermally resistant polymers were thus found to be degraded by light of much longer wavelength than that which is harmful to other common polymers.
Fischer–Tropsch Synthesis in Slurry Bubble Column Reactors: Experimental Investigations and Modeling – A Review

Abstract This paper presents an extensive review of the kinetics, hydrodynamics, mass transfer, heat transfer and mathematical as well as computational fluid dynamics (CFD) modeling of Low-Temperature Tropsch Synthesis (LTFT) synthesis in Slurry Bubble Column Reactors (SBCRs), with the aim of identifying potential research and development areas in this particular field. The kinetic expressions developed for F-T synthesis over iron and cobalt catalysts along with the water gas shift (WGS) reactions are summarized and compared. The experimental data and empirical correlations to predict the hydrodynamics (gas holdup, Sauter mean bubble diameter, and bubble rise velocity), mass transfer coefficients and heat transfer coefficients are presented. The effects of various operating variables, including pressure, temperature, gas velocity, catalyst concentration, reactor geometry, and reactor internals on the hydrodynamic and transport parameters as well as the performance of SBCRs are discussed. Additionally, modeling efforts of SBCRs, using axial dispersion models (ADM), multiple cell recirculation models (MCCM) and computational fluid dynamics (CFD), are addressed. This review revealed the following: (1) Numerous F-T and WGS kinetic rate expressions are available for cobalt and iron catalysts and one must be careful in selecting the appropriate expressions for LTFT. Iron catalyst suffers from severe attrition and subsequent deactivation in SBCRs and accordingly building a costly catalyst manufacturing facility onsite is required to maintain a steady operation of the F-T reactor; (2) Experimental data on the hydrodynamic and transport parameters at high pressures and temperatures, typical to those of actual F-T synthesis, remain scanty when compared with the plethora of studies conducted using air–water systems in small reactors at ambient conditions; (3) Several empirical correlations for predicting the hydrodynamic and mass as well heat transfer parameters are available and one should select those which consider the reactor diameter, gas mixtures and the potential foamability of the F-T liquids; (4) The effect of cooling internals configuration and sparger design on the hydrodynamic and transport parameters, local turbulence, mixing and catalyst attrition are yet to be seriously addressed; (5) The impact of operating variables on the hydrodynamic and transport parameters as well as the overall performance of the SBCRs should be investigated using actual F-T fluid–solid systems under typical pressures and temperatures using a large-scale reactor (>0.15 m ID) in the presence of gas spargers and cooling internals; (6) Significant efforts are still required in order to advance CFD modeling of SBCRs, particularly those pertaining to the relevant closure models, such as drag, lift and turbulence. Also, cooling internals configuration and the design as well as orientation of gas spargers should be accounted for in the CFD modeling; and (7) Proper validations of the CFD formulations using actual systems for F-T SBCR are needed.
Modeling of Water Sorption Isotherms Characteristics of Spray-Dried Cherimoya (Annona cherimola) Purée

Spray drying is a solution to preserve food products from spoiling and moisture adsorption isotherms of dry products can be used to predict their shelf life during storage and distribution. Sorption isotherms of spray-dried cherimoya purée were determined using a gravimetric method between 10°C and 50°C and water activities from 0.05 to 0.96. The data obtained were fitted to Guggenheim, Anderson, and De Boer (GAB), GAB modified, Henderson modified, Oswin modified, Chung–Pfost modified, and Hasley isotherms and the Henderson model best fitted experimental data. The net isosteric heat of sorption values determined using Clausius–Clapeyron ranged from 3.04 and 0.92 kJ/mol between 5% and 30% moisture content in dry basis, respectively. Differential entropy also decreased with moisture content. The compensation theory was applied to sorption isotherms and higher value of isokinetic temperature than harmonic mean temperature denotes that adsorption process was enthalpy controlled and a negative value of Gibbs free energy reflected a spontaneous process.