Miracle-dz/UniFAR-FTUs huggingface dataset:
Analysis of Heterogeneously Catalyzed Ester Hydrolysis Performed in a Chromatographic Reactor and in a Reaction Calorimeter

A discontinuously operated chromatographic reactor and a reaction calorimeter were used to study experimentally and theoretically the heterogeneously catalyzed hydrolysis reactions of four esters (methyl formate, methyl acetate, ethyl formate, and ethyl acetate). Two different batches of an acidic ion-exchange resin were used as catalyst and adsorbent. The relevant distribution equilibria were quantified using pulse chromatographic experiments. The reaction rates were quantified from (a) the shape of the elution profiles and (b) the course of the heat fluxes. To this end, systematic experiments were carried out using fixed beds packed with the catalysts and a reaction calorimeter containing catalyst suspensions. Advantages and disadvantages of these two types of experimental approaches in terms of their potential to extract reliable kinetic parameters were evaluated. A simplified pseudohomogeneous model and the determined parameters were found to be capable of describing the concentration profiles in the .
Molecular Modelling of Ground- and Excited-States Vibrations in Organic Conducting Devices: Hexakis(n-hexyloxy)triphenylene (HAT6) as Case Study

In order to gain insight into fundamental aspects of organic photocell materials, we have calculated ground and excited electronic-state structures and molecular vibrations for an isolated HAT6 molecule (hexakis(n-hexyloxy)triphenylene). Excited-state calculations are carried out using time-dependent density functional theory and frequencies are evaluated analytically using coupled perturbed Kohn–Sham equations. These model calculations have been validated against new infrared and ultraviolet data on HAT6 in solution. The main allowed valence excitation, having the largest oscillator strength, is chosen for the structural and vibrational investigations. Comparison with the ground-state vibrational dynamics reveals surprisingly large spectral differences. In addition, the alkoxy tails, which are usually considered to play only a structural role, are clearly involved in the molecular vibrations and the structural distortion of the excited electronic state compared with the ground state. The tails may play a more important role in charge separation, transport and excited-state relaxation than was previously thought. In this case, chemical modification of the tails would allow vibrational and related properties of organic photocell materials to be tailored.
On the phase composition changes during high temperature oxidation of Pt-modified β-NiAl at 1150°C

Abstract The phase composition of the scales growing during oxidation at 1150°C on Pt-free and Pt-containing (0, 5, 10 and 15 at.%) β-NiAl intermetallic compounds were studied for exposure periods of up to 6 hours using photoluminescence spectroscopy with spatial resolution down to ca 1 μm. Scanning electron microscopy was used to observe the evolution of the surface morphology of the growing scales. It was found that initially unstable polymorphs of Al2O3 oxide (γ, δ and/or θ) developed, which subsequently transformed into α-Al2O3. The transformation occurred relatively early, and after 1 h oxidation essentially α-Al2O3 was detected on all the materials. After 15 min reaction, different regions were found in all cases, and both types of phases, transient aluminas and α-Al2O3 were detected. However, the rate of the phase composition depended on the region: in some regions, the transient aluminas co-existed with a-phase, while in others only transient or only α-Al2O3 were found. Regions composed of only α-Al2O3 were observed on materials containing higher amounts of Pt-additions, i.e. 10 and 15 at. %. This indicates that Pt additions accelerated the phase transformation of alumina polymorphs into α-Al2O3. In the early scales, comprising different regions, α-Al2O3 development was favoured in patches, and only this phase was always detected in ridges growing in cracks formed in patches. Conclusions are inferred concerning the scale evolution on the materials studied as well as on the effect of Pt additions.
Phosphorus sorption in soils of the Mekong delta (Vietnam) as described by the binary Langmuir equation

Phosphate adsorption isotherms were determined for 20, mostly very acidic, soils from the Mekong Delta. The experimental data were well described by a binary Langmuir equation which considers two groups of sorption sites that differ in their P bonding energies. The maximum P-sorption capacities of these sites were related to the soil properties by simple linear correlation and by stepwise multiple regression. Results suggest that high energy sites are on Al-oxihydroxides or small Al-substituted Fe-oxides and, to a lesser extent, on poorly ordered Fe-oxihydroxides. On the other band, the P-sorption capacity of low energy sites is mainly related to clay content, and it increases as pH decreases. These sites are also positively correlated with organic carbon and poorly crystalline Fe-oxihydroxides. However, as these two variables are closely correlated with each other, organic matter is likely to be considered as an indirect factor of P fixation through its association with Fe-oxihydroxides and not as an important source of P-sorption sites. The maximum sorption capacity, i.e. the sum of sorption capacities of the two groups of sites, is well described (r(2) = 0.88) by an equation that takes into account the four variables identified above: Al-bearing oxihydroxides, poorly ordered Fe-oxihydroxides, clay content and pH. Grouping the soils according to the orders of Soil Taxonomy, the P-sorption capacity increases in the following sequence: ultisols < entisols < inceptisols. A P concentration often considered adequate for plant nutrition is 0.2 mg P l(-1) solution, and only the high energy sites are involved in sorption at that concentration. Thus an equation including only Al- and Fe-oxihydroxides could be used to fix P norms in these soils.
Effect of ascorbic acid supplementation on corticosterone levels and production parameters of white leghorn exposed to heat stress

Meteorological factors such as high ambient temperature and high relative humidity exert adverse effects on poultry production. Stressful stimuli, such as environmental, pathological and nutritional disturbances, to mention a few, can cause stress like impairing poultry performance and evoking the behavioural and physiological chain reactions. Thermal stress not only reduces production but also causes higher mortality in poultry thus, inflict considerable economic losses. In the present research investigation a possibility was explored to investigate the effect of ascorbic acid on corticosterone level and production parameters during heat stress in White Leghorn birds.A total of 96 White Leghorn birds were randomly divided and maintained in comfort (26±1.0 °C) and heat stressed (40±5.0 °C) conditions. Layers were divided into 4 groups and each group consisting of 12 birds in 2 replicates. G1 group was kept as control. G2, G3 and G4 group was supplemented with 100, 200 and 300 mg ascorbic acid (AA) respectively. The overall mean concentration of plasma HSP70 concentration showed non-significant difference between comfort and heat stressed birds. The overall mean concentration of corticosterone between comfort and heat stressed condition in egg type grower showed significant difference (p
CO2 Adsorption on Modified Mg–Al-Layered Double Hydroxides

Because of increases in the burning of fossil fuels, there is an increased emission of pollutant gases (e.g. CO2) into the atmosphere. An alternative to minimize these emissions is to capture these gases using porous materials, such as layered double hydroxides (LDHs). In this study, LDHs were synthesized by co-precipitation of ion salts of Mg2+ and Al3+. After the synthesis, the materials were treated with a template to expand the layers. The samples were then characterized by X-ray diffraction, thermogravimetric analysis/derivative thermogravimetry, adsorption/desorption of nitrogen, scanning electron microscopy/energy-dispersive X-ray spectroscopy and transmission electron microscopy. A CO2 adsorption study was then performed to determine the adsorption capacity of the material in accordance with the contact time between the gas and the adsorbent. The adsorption capacities of LDHs and LDHs-P123 for CO2 were 0.72 and 1.36 mmol/g, respectively, showing satisfactory results post-treatment.
Rapid Analysis of the Main Components of Glycyrrhizae Uralensis Fisch by UPLC/Q-TOF-MS

A rapid method for analysis of the main components of Radix Glycyrrhizae (RG) was developed using ultra-performanceliquid chromatography with quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF-MS). Previous study demonstrated that RG had antivirus, antioxidant，anti-tumor and other bioactivities. The separation analysis was performed on Waters Acquity UPLC system and the accurate mass of molecules and their fragment ions were determined by Q-TOF MS. Fourty compounds including triterpenoid saponins, flavonoid glycosides and flavonoid aglycones,coumarins, were identified and tentatively deduced on the basis of their element compositions, MS/MS data and relevant literatures. The results demonstrated that triterpenoid saponins, flavonoid glycosides and flavonoid aglycones were the main constituents of RG. Furthermore, an effective and rapid pattern was established allowing for comprehensive and systematic characterization of the complex samples.
Estimation of the phosphorus sorption capacity of acidic soils in Ireland

The test for the degree of phosphorus (P) saturation (DPS) of soils is used in northwest Europe to estimate the potential of P loss from soil to water. It expresses the historic sorption of P by soil as a percentage of the soil's P sorption capacity (PSC), which is taken to be α (Alox + Feox), where Alox and Feox are the amounts of aluminium and iron extracted by a single extraction of oxalate. All quantities are measured as mmol kg soil−1, and a value of 0.5 is commonly used for the scaling factor α in this equation. Historic or previously sorbed P is taken to be the quantity of P extracted by oxalate (Pox) so that DPS = Pox/PSC.
Curing kinetics of liquid-crystalline epoxy resins

Abstract By endcapping mesogenic rigid rod molecules with reactive epoxy groups a novel class of liquid-crystalline thermoset has been obtained. In fact is has been shown that the nematic molecular arrangement is sustained over the crosslinking reaction of liquid-crystalline epoxy resins when the curing reaction is carried out in the thermal stability range of the liquid-crystalline phase. Calorimetric analysis was used in characterizing the isothermal cure. An unsophisticated model is proposed for evaluating the activation energies of the crosslinking reaction. For liquid-crystalline epoxy resins lower activation energies result with respect to the cure reactions for non liquid-crystalline epoxy resins.
Calcium oxide sintering in atmospheres containing water and carbon dioxide

Etude de la cinetique du frittage de CaO en fonction de la temperature et de la pression partielle, influence de l'addition de vapeur d'eau et de dioxyde de carbone.On etudie l'evolution de la porosite et de l'aire superficielle au cours du processus
Study of the effect of Al, Cr and Sn additions on the microstructure and properties of Nb silicide based alloys

The effects of Al, Cr and Sn on segregation, microstructure, phase stability and hardness of Nb-24Ti-18Si-5X (X = Al, Cr, Sn, at%) alloys were studied. The microstructure of the as cast alloys with Cr, Al and Sn respectively contained (Nb,Ti) ss , Nb 3 Si, αNb 5 Si 3 and C14-NbCr 2 Laves, (Nb,Ti) ss and βNb 5 Si 3 and (Nb,Ti) ss , Nb 3 Sn and Nb 5 Si 3 . The microstructures of the heat treated alloys with Al and Cr (1500 o C/100 h) contained (Nb,Ti) ss and αNb 5 Si 3 and the alloy with Sn (1200 o C/100 h) contained (Nb,Ti) ss , Nb 3 Sn and αNb 5 Si 3 . Compared with Al and Cr, alloying with Sn enhanced the stability of the as cast microstructure, caused strong macrosegregation of Si and Ti, suppressed the segregation of Ti in the (Nb,Ti) ss that was promoted by Al and Cr, had the strongest effect on the macrohardness of the cast and heat treated alloys and on the vol% of the Nb ss . All three alloying additions promoted the transformation of βNb 5 Si 3 to αNb 5 Si 3 during heat treatment and decreased the hardness of Nb 5 Si 3 in the as cast alloys with Sn having the strongest effect and Al the weakest. After the heat treatment the hardness of Nb 5 Si 3 increased in the alloys containing Cr and Sn and decreased in the Al containing alloy with Cr having the strongest effect.
Solution Growth and Characterisation of L‐alanine Single Crystals

Single crystals of L-alanine have been grown from buffered aqueous solutions and characterised as to their optical quality via wavefront distortion analysis, electrooptical response and harmonic generation efficiency. Refraction indices as well as phase matching loci were found in satisfactory agreement with previously published data for crystals grown in non buffered solution. Estimates for the electro-optical response are reported for the first time. The experimentally observed crystal habit is discussed in terms of morphological importance (M.I.), which was found to be in disagreement with the predictions of crystallographic criteria based on the interplanar distance d hkl , on the periodic bond chains (PBC) and the attachment energy E att . This disagreement is tentatively attributed to the presence of impurities and non-appropriate supersaturation conditions.
15N‐NMR spectroscopy 32. Synthesis and characterization of polyelectrolytes based on polyaminamides

The titrations of the polyammamides prepared from adipic acid and diethylenetriamine or di(3-aminopropyl)methylamine were monitored by means of natural-abundance 15N-(NMR) nuclear magnetic resonance spectra. Opposite shift effects were found for amine and amide nitrogens upon protonation of the amino groups. These shift effects allow one to distinguish substitutions involving exchange of electric charges from other substitutions without isolation of the polymers. Reactions of the polyaminamides with β-propiolactone, γ-butyroslution, methyl-methane sulfonate, prolyleneoxide, epichlorohydrine, maleic acid anhydride, succinic acid anhydride, carbon dioxide, ethylchloroformate, and methyne sulfonylchloride were carried out in water, and the resulting polyelectrolytes were characterized by means of 15N-NMR spectra.
Contact electrification of silica and soda glass

Charge transfer from metals to silica (and SiO2 grown on silicon) is predominantly negative and significantly dependent on the workfunction of the contacting metal. Charge transfer to soda glass, on the other hand, is strongly positive and does not vary much with metal workfunction; these features are unchanged by a wide range of surface treatments and are clearly intrinsic to the material itself, not an accidental result of some particular surface condition. The authors present strong evidence indicating that the positive charging of glass is a consequence of the presence of sodium (that is, in ordinary glass; other metals such as silver can be similarly effective). One consequence of this is that the charging of glass can be strongly modified by exposure to water, which leaches out the metallic ions. The presence of mobile sodium ions also causes pronounced charge accumulation when contacts are repeated to the same spot, an effect which is virtually absent from silica. Their observations suggest that the amount of charge transfer to glass must be limited by some factor other than the density of electron donor sites, e.g. by transfer of electrons or ions during separation.
Rehydration properties of dried onion

Abstract The effect of pretreatment preceding convective drying and the mode of drying on reconstitution properties of dried onion was investigated. Soaking in water, dipping in starch solution and osmotic dewatering were used as pre‐drying treatments. Convective drying at 60, 70, and 80°C, infrared drying and convective drying assisted with microwaves were applied to remove water from raw onion. Rehydration was done in water at room temperature and in boiling water. In general amount of absorbed water and increase in mass during rehydration, both were higher for pretreated material than those observed with dried raw onion. The mode of drying seemed to affect the course of rehydration of dried onion, and to improve its reconstitution properties. However, this was observed at room temperature rehydration only. Pre‐drying treatment followed by convection drying affected much stronger reconstitution properties of dried onion than the mode of drying.
Synthesis, characterization and band gap energy of poly(ε-caprolactone)/Sr-MSA nano-composite

A mercaptosuccinic acid (MSA) decorated Sr nano-particle (NP) was prepared and characterized by using various analytical techniques and was used as a chemical initiator for the ring opening polymerization (ROP) of ε-caprolactone (CL). The ROP of CL was carried out at various experimental conditions under N2 atmosphere with mild stirring. The initiating efficiency of MSA-decorated Sr NP was tested in terms of Fourier transform infrared-relative intensity, melting temperature (Tm), degradation temperature (Td) and molecular weight (Mw) of poly(ε-caprolactone) (PCL), differential scanning calorimetry, UV–visible spectroscopy, field emission scanning electron microscopy, thermogravimetric analysis and gel permeation chromatography analytical techniques. The nuclear magnetic resonance spectrum confirms the chemical structure of PCL. While increasing the [M/I] ratio, the Mw of PCL was linearly increased. The band gap energy of Sr was determined from the UV–visible spectrum. The reflectance study proves the hydrophobic nature of the Sr-hybrid and its nano-composite formation with PCL.
Analysis of KLa Measurement Methods in Stirred Vessels: The Role of Experimental Techniques and Fluid Dynamic Models

Several dynamic and steady-state methods have been proposed in the literature for measuring the mass transfer coefficient in gas-liquid stirred vessels. Analysis has also been developed about the fundamentals of the most interesting techniques. Similarly, the flow behaviour of the gas and the liquid phases has been modelled in various waysthe different models often resulting in different coefficient estimates. Cross checking of a number of techniques and of various models has already been performed for a number of cases. However, not all the implications are clear and have been retained, especially for high-aspect-ratio equipment stirred with multiple impellers.In this paper, the main problems in KLa characterisation are analysed: the most promising techniques and flow models are reviewed critically and several combinations of experimental methods and models have been tested with the purpose of providing information regarding their choice. Vessels stirred with sets of multiple impellers of different types as well as coalescing and non-coalescing gas-liquid systems have been considered. Recommendations about the use of some of the mentioned tools are also given in relation to the final use of the coefficient.
The 3D structure of the penumbra at high resolution from the bottom of the photosphere to the middle chromosphere

Abstract Sunspots are the most prominent feature of the solar magnetism in the photosphere. Although they have been widely investigated in the past, their structure remains poorly understood. Indeed, due to limitations in observations and the complexity of the magnetic field estimation at chromospheric heights, the magnetic field structure of sunspot above the photosphere is still uncertain. Improving the present knowledge of sunspot is important in solar and stellar physics, since spot generation is seen not only on the Sun, but also on other solar-type stars. In this regard, we studied a large, isolated sunspot with spectro-polarimeteric measurements that were acquired at the Fe I 6173 nm and Ca II 8542 nm lines by the spectropolarimeter IBIS/DST under excellent seeing conditions lasting more than three hours. Using the Non-LTE inversion code NICOLE, we inverted both line measurements simultaneously, to retrieve the three-dimensional magnetic and thermal structure of the penumbral region from the bottom of the photosphere to the middle chromosphere. Our analysis of data acquired at spectral ranges unexplored in previous studies shows clear spine and intra-spine structure of the penumbral magnetic field at chromopheric heights. Our investigation of the magnetic field gradient in the penumbra along the vertical and azimuthal directions confirms results reported in the literature from analysis of data taken at the spectral region of the He I 1083 nm triplet.
High Performance Liquid Chromatographic Analysis of Soybean Phospholipids

An HPLC method was optimized to analyze soybean phospholipids. It uses a silica column with UV detection at 210 nm, and a mobile phase consisting of hexane, isopropanol and water. Separation is achieved by keeping the hexane to isopropanol ratio constant and varying the water concentration in a gradient elution program. Components in the HPLC chromatogram were identified by comparison with retention times of authentic compounds. The method was quantitative for phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), and lyso-phosphatidylcholine (LPC). To determine these components quantitatively, standard curves of authentic compounds were prepared. The peak area of the compound in the mixture was converted into weight percent with the standard curves. Unsaturation was the functional group measured by the detector, therefore, the accuracy of the quantitative results depended upon the degree of unsaturation in the standard compounds. Unsaturation in triglycerides and phospholipids may vary depending upon the season of harvest and the climate of location and production. Two commercial samples of granular soybean lecithin were analyzed. Soybean lecithin was extracted with alcohol and the alcohol-soluble and alcohol-insoluble fractions were analyzed. The results differed both qualitatively and quantitatively.
In Vitro Screening of Blood-Brain Barrier Penetration of Monoquaternary Acetylcholinesterase Reactivators

The HPLC method for prediction of drug penetration into the CNS was examined in our study. In this in vitro study, we determined the ability of monoquaternary AChE reactivators to penetrate through blood-brain barrier (BBB). Three reactivators varying in the position of oxime group on the pyridinium ring (2-PAM, 3-PAM and 4-PAM) were evaluated. As a result, the position of the oxime group on the pyridine ring plays a role for penetration of oximes into brain. The best position of oxime group seems to be position four. The location on the position two and three is not favorable for penetrating through BBB.
Copper complexation in English Rivers

Abstract Data for copper complexation capacity (CC), determined by cathodic stripping voltammetry, are presented for 36 English rivers. Values for CC were between 40 and 500 nM. No predictive relationship between major water quality parameters and CC was found. A comparison of determinations made on the same water bodies over several years points towards consistency of CC with time. It is concluded that, in river waters of a wide range of types, forms of copper complexed by organic matter predominate substantially over free or inorganic forms of the metal.