Miracle-dz/UniFAR-FTUs huggingface dataset:
Lignin and cellulose fractionation in decomposition studies using acid‐detergent fibre methods

Abstract Lignin methods based on an acid‐detergent fibre pre‐extraction were evaluated for grass, straw, heather and spruce litter. Quantification following oxidative attack to destroy the lignin by permanganate proved to be unreliable for the woody heather material and spruce litter. In contrast the method of isolation involving hydrolysis of the cellulose component with 72% sulphuric acid (H2SO4) was precise and robust. The acid detergent reagent dissolves most of the hemi‐cellulose and offers the opportunity to quantify the residual alpha‐cellulose fraction.
Photocatalytic degradation of methylene blue in ZIF-8

Metal–organic frameworks (MOFs), a new class of porous crystalline materials, have attracted great interest as a promising candidate for sustainable energy and environmental remediation. In this study, ZIF-8, a versatile MOF based on imidazolate ligands, was selected as a photocatalyst to decompose methylene blue (MB) under UV light irradiation. The influence factors, kinetics, and mechanism of photocatalytic MB degradation and stability of ZIF-8, were also studied. The results revealed that the ZIF-8 photocatalyst exhibited efficiently photocatalytic activity for MB degradation under UV irradiation, which was confirmed through the detection of hydroxyl radicals (˙OH) by a fluorescence method. The MB degradation over the ZIF-8 photocatalyst followed a pseudo-first-order kinetics model. ZIF-8 worked effectively over a wide pH range from 4.0 to 12.0, and showed both high adsorption capacity and degradation efficiency for MB in a strong alkaline environment. The enhanced efficiency in a strong alkaline environment resulted from the higher charged ZIF-8 (pH > pHpzc) and the elevated yield of ˙OH facilitated by increased OH− concentration. The possible pathway of photocatalytic degradation of MB in ZIF-8 was proposed. The results indicated that ZIF-8 can be used as a highly efficient photocatalyst to decompose organic pollutants.
Influence of soil calcium, potassium, and pH on development of leaf tipburn of cabbage in eastern North Carolina

Abstract Three hypotheses that involved manipulation of soil calcium (Ca), potassium (K), and pH in relation to the occurrence of leaf tipburn of cabbage in eastern North Carolina (NC) were formulated and tested: 1) adding K to soil will increase (induce) leaf tipburn; 2) adding Ca and K together to soil will block K‐related tipburn induction, and 3) raising soil pH to levels of 6.0 to 6.5 will decrease leaf tipburn. Six experiments were conducted in commercial cabbage production fields in eastern NC in 1996 and 1997 to test these hypotheses. Hypothesis 1 was accepted since higher rates of K significantly (p<0.05) increased leaf K concentration, soil K content and leaf tipburn incidence compared with the control. Total cabbage yield increased as K rates increased, however, significant differences were only observed between the control and the highest rate (365 kg K ha‐1) in 1996. Hypothesis 2 was accepted since adding increased amounts of Ca and K. did not significantly increase leaf tipburn incidence. Hypothesis 3 was rejected since a range of soil pH from 5.3 to 6.6 did not increase or decrease leaf tipburn incidence, nutrient uptake or total yield. These data suggest that leaf tipburn of cabbage can be increased (induced) with excessive K fertilization and that this practice may be associated with the disorder observed in NC. Also, the addition of Ca with K may potentially reduce the risk associated with K‐related leaf tipburn of cabbage.
Direct Imaging of Cl‐ and Cu‐Induced Short‐Circuit Efficiency Changes in CdTe Solar Cells

To achieve high‐efficiency polycrystalline CdTe‐based thin‐film solar cells, the CdTe absorbers must go through a post‐deposition CdCl2 heat treatment followed by a Cu diffusion step. To better understand the roles of each treatment with regard to improving grains, grain boundaries, and interfaces, CdTe solar cells with and without Cu diffusion and CdCl2 heat treatments are investigated using cross‐sectional electron beam induced current, electron backscatter diffraction, and scanning transmission electron microscope techniques. The evolution of the cross‐sectional carrier collection profile due to these treatments that cause an increase in short‐circuit current and higher open‐circuit voltage are identified. Additionally, an increased carrier collection in grain boundaries after either/both of these treatments is revealed. The increased current at the grain boundaries is shown to be due to the presence of a space charge region with an intrinsic carrier collection profile width of ≈350 nm. Scanning transmission electron microscope electron‐energy loss spectroscopy shows a decreased Te and increased Cl concentration in grain boundaries after treatment, which causes the inversion. Each treatment improves the overall carrier collection efficiency of the cell separately, and, therefore, the benefits realized by each treatment are shown to be independent of each other.
Step Coverage Characteristics of Pb(Zr, Ti)O3 Thin Films on Various Electrode Materials by Metalorganic Chemical Vapor Deposition

The step coverage characteristics of Pb(Zr, Ti)O3 (PZT) thin films on steps with various electrode materials, such as Pt/SiO2, Ir/SiO2 and IrO2/SiO2, by metalorganic chemical vapor deposition (MOCVD) were investigated. The step coverage of PZT films deposited on Pt/SiO2 at 500 and 550° C was 80–87%. Deformation of Pt/SiO2 steps was observed when PZT films were deposited at 600° C. The cause of this deformation of steps was mainly the diffusion of Pb into the steps. When PZT thin films were deposited on Ir/SiO2 at 500–600° C and IrO2/SiO2 at 500 and 550° C, good step coverage of 76–93% and 70–85% was obtained, respectively.
Design of a novel calcium-selective optode membrane based on neutral ionophores

A large variety of new optical ion-sensor constructions (optodes) can now be realized by using a poly(vinyl chloride) (PVC) membrane that incorporates a cation-selective neutral ionophore, a specially tailored H + -selective neutral chromoionophore, and lipophilic anionic sites in the same plasticized PVC membrane. Such membranes generally combined the advantages of a highly selective and reversible recognition of given ionic substrates and of a straightforward optical transduction of the recognition process
DESIGNED SYNTHESIS OF NANOPOROUS ORGANIC POLYMERS FOR SELECTIVE GAS UPTAKE AND CATALYTIC APPLICATIONS

IV Chapter 1Introduction 1.1 Porous Organic Polymers as a New Class of Porous Materials. 1 1.2 Synthesis of Porous Organic Polymers via a Topology-Directed Approach . 3 1.3 Carbon Dioxide Separation. 6 1.4 Current Sorbents for CO2.10 1.4. 1 Amine Solutions. 10 1.4. 2 Porous Adsorbents. 11 1.4. 2.1 Zeolites . 13 1.4. 2.2 Porous Carbons.14 1.4. 2.3 Metal-Organic Frameworks.14 1.4. 2.4 Porous Organic Polymers . 15 1.4. 2.4. 1 Synthesis of Nitrogen-Rich Porous Organic Polymers for Selective CO2 Capture . 18 1.5 Regeneration Processes for Solid CO2 Sorbents . 20 1.6 Porous Organic Polymers in Heterogeneous Catalysis. 21 1.7 Porosity and Gas Uptake Measurements . 22 List of References. 25
Interfacial spin order in exchange biased systems

The phenomenon of exchange bias in which a ferromagnet is grown in intimate contact with an antiferromagnet leads to a shifted hysteresis loop. All analytical theories developed to explain this effect predict values of the shift of the loop that are too large, often by an order of magnitude. In many numerical models an interface exchange coupling constant C∗ is introduced to account for these discrepancies. In this work we describe a series of experiments, which reveals the temperature and field dependence of this interfacial spin order that account for the weakened coupling between the layers. We also show that this order has a marked temperature dependence at temperatures down to ∼50 K. At temperatures below 50 K we observe a sudden marked increase in the observed exchange bias of up to a factor of 2, which we attribute to a spontaneous spin ordering of the interfacial spins analogous to that which occurs in spin-glass systems.
Microwave, Air and Combined Microwave-Air Drying of Grape Leaves (Vitis vinifera L.) and the Determination of Some Quality Parameters

Abstract Grape leaves (Vitis vinifera L.) weighing 50 g (±0.08) with a moisture of 4.08 kg(moisture) kg−1(dry matter) (75.35% wb) were dried using three different drying methods: microwave, air and combined microwave-air. Drying continued until the leaf moisture decreased to 0.14 (±0.01) kg(moisture) kg−1(dry matter) (9.07% (±0.20) wb). Drying periods lasted 5–11, 30–70 and 1.5–6 min for microwave, air and combined microwave-air drying, respectively, depending on the drying level. In this study, measured values of moisture were compared with values of predicted obtained from several thin-layer equations; the Alibas Model was found to have the best fit. The optimum drying period, color and ascorbic acid content were obtained by using the combined microwave-air drying method with the optimum combination of 500 W of microwave power at a temperature of 75°C.
Orientation control of rhomboedral PZT thin films on Pt/Ti/SiO2/Si substrates

Highly (111)- and (001)-oriented rhomboedral PZT thin films have been grown at 500 °C on platinized silicon substrates by in situ RF magnetron sputtering. Crystallization of the perovskite phase was possible provided that a thin TiO x buffer layer was deposited prior to the PZT. Control of PZT films orientation is demonstrated by changing the O 2 /(Ar + O 2 ) ratio in the plasma gas during the TiO x sputtering and its consequences on electrical properties of the ferroelectric samples are presented. The structural properties of the TiO x buffer layer were studied by means of transmission electronic microscopy in order to understand the relation between the TiO x seeding and the orientation control of the PZT film.
Preparation and characterization of Cu(In1−xGax)3Se5 thin films

Polycrystalline Cu(In1−xGax)3Se5 thin films were prepared by four source evaporation with controlling and shielding of the molecular beams from elemental sources. Ga content x, can be controlled by deposition times of CuIn3Se5 and CuGa3Se5 layers, which form Cu(In1−xGax)3Se5 films through the interdiffusion. X‐ray diffraction analyses showed that the films with x≲0.5 have an ordered vacancy chalcopyrite and the films with x≳0.5 have a zinc blende structure. The optical band gap of the films linearly increased from 1.23 eV (x=0) to 1.85 eV (x=1) with increasing Ga content. The conductivity of the films was about 10−6/Ω cm and about 10−7/Ω cm under and above x=0.3, respectively.
Preparation and characterization of starch/polycaprolactone blend

To make starch/polycaprolactone (PCL) blend with high miscibility, starch was chlorinated (starch-Cl) by using methanesulfonylchloride (CH3SO2Cl) in dimethylformamide (DMF) prior to blending. Starch-Cl/PCL blends were prepared by the mixing between starch-Cl and PCL solutions under various conditions. To study the change of structure, thermal and physical characteristics of starch-Cl/PCL blend, FTIR, DSC, SEM, and solvent resistance were measured. By blending starch-Cl and PCL, a chemical reaction occurred partially in blend (FTIR result); thereby, the miscibility (DSC and SEM results) and solvent resistance were increased. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1716–1723, 2004
Differential response of corn inbreds to calcium

Abstract Differential responses were noted among several corn (Zea mays L.) inbreds for Ca when grown in nutrient solutions at varied Ca stresses. Properties of one of the more “Ca‐efficient”; inbreds (Oh43) compared to one of the more “Ca‐inefficient”; inbreds (A251) are reported. Oh43 produced more dry matter and developed fewer Ca stress symptoms when grown at both low and high Ca or with high Mg and K than A251. Comparable dry matter was produced by Oh43 at 4 times less Ca than A251. Oh43 also produced more dry matter per unit Ca than A251. Oh43 leaves and roots had lower Ca concentrations than A251 leaves and roots. With added Ca to solutions, Mg, K, Mn, Zn, and Cu concentrations decreased more in A251 than in Oh43. A251 contained higher P concentrations than Oh43. Functional and critical Ca concentrations appeared to be lower in Oh43 than in A251. Oh43 should grow and adapt better to Ca stress conditions than A251.
Rheological behaviors of hydroxypropylated sweet potato starches influenced by guar, locust bean, and xanthan gums.

This study examined the steady flow and dynamic rheological behaviors of hydroxypropylated sweet potato starch (HPSPS) pastes mixed with guar gum (GG), locust bean gum (LBG), and xanthan gum (XG) at different concentrations (0, 0.3, and 0.6%). The HPSPS-gum mixtures had higher shear-thinning fluid characteristics than the control (0% gum) at 25°C. The addition of the gums resulted in an increase in the consistency index (K) and apparent viscosity (η a , 100 ). The dynamic moduli (G', G") and complex viscosity (η*) values of the HPSPS-gum mixtures were higher than those of the control, and they increased with an increase in gum concentration. In particular, the presence of XG at 0.6% in the HPSPS-gum mixture systems gave rise to the greatest viscoelastic properties among the gums examined at different concentrations. The tan 8 (ratio of G"/G') values (0.35-0.57) of the HPSPS-GG and HPSPS-XG mixtures were much lower than those of the control (0.82) and HPSPS-LBG (0.88-1.06), indicating that the elastic properties in the HPSPS-gum mixture systems were strongly affected by the additions of GG and XG. These steady flow and dynamic rheological parameters indicated there were synergistic interactions between the HPSPS and gums. The synergistic effects of the gums and modified starch were hypothesized by considering the molecular incompatibility and molecular interactions between the gums and HPSPS.
Breakdown characteristics in air gaps with artificial floating metals under DC voltage

The DC breakdown characteristics of a sphere-to-sphere gap with conducting objects supported by an insulator rod in atmospheric air are investigated experimentally to provide fundamental parameters determining the breakdown voltage in the presence of floating objects around DC power apparatus by an air insulation. The shape of tested floating objects made of metal is plate, needle or sphere. Experimental results show that the main factors affecting the breakdown voltage are the shape and size of floating objects, the object location and the gap length. If the object is placed at the location giving the lowest breakdown voltage, any object lowers the breakdown voltage below that without the relevant objects. >
Influence of Cation Structure on Physicochemical and Antiwear Properties of Hydroxyl-Functionalized Imidazolium Bis(trifluoromethylsulfonyl)imide Ionic Liquids

A series of hydroxyl-functionalized imidazolium bis (trifluoromethylsulfonyl)imide ionic liquids (ILs) with alkyl chain lengths ranging from C1 to C10 were successfully synthesized and systematically investigated as lubricants for steel–steel contacts at room temperature and three different lubricating conditions. The effect of either hydroxyethyl group or alkyl chain length on physicochemical and tribological properties of the ILs was discussed at length, and the optimum chemical structure was also obtained. It was found that incorporation of a hydroxyethyl group to the imidazolin cation had a great impact on thermal stability, frictional coefficient, and wear but less impact on viscosity and corrosivity. It is also found that increasing alkyl chain length in the imidazolin cation had a significant influence on corrosion, the frictional coefficient, and wear but the effect dropped rapidly from C1 to C6 and progressively recovered as it increased from C6 to C10. To a much lesser extent, a similar effect was seen on thermal stability. As expected, increasing alkyl chain length monotonically increased viscosity. Furthermore, the lubrication mechanism in the friction process was explored in depth by means of scanning electron microscopy (SEM) and X-ray photoelectron spectrometry (XPS), and a proposed interaction model between the ILs and the friction surfaces was provided.
Mechanisms of Palygorskite and Sepiolite Alteration as Deduced from Solid-State 27A1 and 29Si Nuclear Magnetic Resonance Spectroscopy

The mechanisms of palygorskite and sepiolite alteration to smectite under mild hydrothermal conditions were investigated by solid-state 27Al and 29Si magic-angle spinning-nuclear magnetic resonance (MAS-NMR) spectroscopy, X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). Palygorskite altered to smectite in the presence of NaOH at 150°C. 27Al MAS-NMR spectroscopy showed that the Al coordination changed from chiefly octahedral in palygorskite to chiefly tetrahedral in the smectite product. 29Si MAS-NMR spectroscopy showed that the nearest neighbor environment of Si also changed when palygorskite altered to smectite. The XRD data showed that the synthetic smectite is trioctahedral in nature with tetrahedral charge. The TEM results revealed that the needle-like morphology of palygorskite was preserved in the product smectite. The MAS-NMR results in conjunction with the above XRD and TEM studies suggest that the mechanism of palygorskite alteration was a dissolution and recrystallization process rather than a solid-state reorganization to form 2:1 layer silicate units from the preexisting chain structure. Sepiolite altered to smectite in the presence of 2 N salt solutions at 300°C. The trioctahedral nature of the product smectite as detected by XRD and the foil-like morphology of product smectite as shown by TEM suggest that the mechanism of sepiolite transformation to smectite was also a dissolution and recrystallization process. The tetrahedral Al coordination detected by 27Al MAS-NMR in the smectite altered from sepiolite corroborated the XRD and TEM results.
Calcium uptake and distribution in plants

Abstract Calcium uptake and distribution in plants are influenced by many factors. Root uptake seems to be independent of metabolic inhibitors but transfer to shoots is drastically reduced by such inhibitors. K uptake increases with root temperature which in turn results in depressed Ca uptake. Plant species differences in the proportion of K vs Ca uptake are often related to root cation exchange capacity. The cations K, Mg, Na, NH4+, and H+ directly and indirectly depress Ca uptake and distribution. Their effects are more pronounced at low Ca concentrations than at high. Lime‐induced chloros.is is associated with depressed Ca levels in leaves and tests under controlled conditions indicate that bicarbonate results in root retention of Ca and a decrease of Ca in leaves. Nitrate as a complementary ion promotes Ca uptake by plants. Trace metals in excess inhibit calcium uptake. Aluminum in particular greatly depresses Ca retention by roots as well as Ca uptake and transport to shoots. Leaves generally increa.
Critical state soil mechanics analysis of the constant cell volume triaxial test

We have developed a critical state, stress‐strain analysis that predicts the entire sequence of states from start to the end of a constant cell volume triaxial test in p‐q‐v‐ɛz, space, where p is the spherical stress, q is the deviator stress, v is the specific volume and ɛz is the axial strain. The analysis requires five soil properties to be specified, these being the critical state properties (M, λ and κ) and two elastic properties (any two of E, η, G and K—all four can be found from any two).
Prenylated flavonoids from the fruits of Sinopodophyllum emodi and their cytotoxic activities

Thirteen new prenylated flavonoids, sinoflavonoids C–O (1–13), were isolated from the fruits of Sinopodophyllum emodi together with eleven known analogues (14–24). Their structures were elucidated on the basis of spectroscopic evidence. The cytotoxic activities of all isolated compounds were evaluated against MCF-7 and HepG2 cell lines. By the preliminary structure–activity relationships, it was first discovered that the simple, non-prenylated 5,7,3′,4′-tetrahydroxyflavonol analogues (22 and 23) showed higher cytotoxic activities than the corresponding prenylated ones (1–2, 4–21, and 3 and 24). Compound 22 exhibited the most potent cytotoxicity against MCF-7 and HepG2 cell lines with IC50 values of 3.14 and 2.08 μM, respectively.
Scaling Model of Low-Temperature Transport Properties for Molecular and Ionic Liquids

The universal scaling concept is applied to the low-temperature range of any liquid states and substances located between the melting () and normal boiling () points far away from the critical region. The physical reason to develop such approach is the revealed collapse of all low-temperature isotherms onto the single universal one argued by the model of fluctuational thermodynamics (FT) proposed recently by author. The pressure reduced by the molecular parameters of the effective short-range Lennard-Jones (LJ) potential depends here only on the reduced density. To demonstrate the extraordinary predictive abilities of the developed low-temperature scaling model it has been applied to the prediction of equilibrium and transport (kinetic and dynamic viscosity, self-diffusion, and thermal conductivity) properties not only for molecular liquids but also for molten organic salts termed ionic liquids (ILs). The best argument in favor of the proposed methodology is the appropriate consistency with the scarce experiments prediction of transport coefficients for ILs on the base of universal scaling function constructed for the simplest LJ-like liquid argon. The only input data of any substance for prediction are the linear approximations of -dependent density and isobaric heat capacity taken from the standard measurements at atmospheric pressure.
Manejo da adubação nitrogenada e utilização do nitrogênio (15N) pelo milho em Latossolo Vermelho

Nitrogen is the nutrient that is most absorbed by corn crop, influences grain yield most, and requires the most complex management. The objective of this work was to evaluate the effect of nitrogen (urea 15N) rate and split-applications, on grain yield, N fertilizer utilization and amount of soil native N absorbed by corn crop in a Red Latosol. The experiment was arranged in a randomized complete block design, with nine treatments and four replications, represented by five N rates: 0, 55, 95, 135 and 175 kg ha-1 N, 15 kg of N applied at sowing, and the remaining amount in different split-applications: 40 and 80 kg ha-1 applied in single rates in the 8-leaf stage or half in the 4-leaf stage + half in the 8-leaf stage; 120 kg ha-1 split in 1/2 + 1/2 or 1/3 + 1/3 + 1/3 in the 4, 8 or 12-leaf stage; 160 kg ha-1 split in 1/4 + 3/8 + 3/8 or 1/4 + 1/4 + 1/4 + 1/4 in the 4, 8, 12-leaf stages or at flowering and pollination. The N fertilizer use by corn was, on average, 39 %, and the soil was the main source of the nutrient for the crop. With three split applications of 135 kg ha-1 N, until 8 leaves, the N fertilizer use is most efficient (52 %) and the grain yield highest.