Miracle-dz/UniFAR-FTUs huggingface dataset:
Nitrogen mineralization in sub‐tropical paddy soils in relation to soil mineralogy, management, pH, carbon, nitrogen and iron contents

The nitrogen (N) requirement for paddy rice cultivated in Bangladesh amounts to approximately 80 kg N ha−1. Lack of knowledge on N mineralization from soil organic matter leads farmers to meet this N requirement exclusively by costly mineral fertilizers, which have typically an efficiency of less than 40%. We assessed to what extent routinely analysed soil properties (N and carbon (C), texture, pH, extractable iron (Fe), aluminium (Al) and manganese (Mn), soil mineralogy and length of the annual inundation period) are able to predict net aerobic and anaerobic N mineralization in paddy soils. Both soil N and C correlated positively with the aerobic but not with the anaerobic N mineralization rate. Instead, relative anaerobic N mineralization showed a significant negative correlation with soil N content. We observed no significant influence of clay mineralogy on soil N mineralization. Aerobic but not anaerobic N mineralization increased with length of the annual inundation period while the proportion of the soil N that was mineralized during 120 days decreased. The large clay content of fields that are inundated for 9–10 months annually explains the co‐occurrence of large soil N contents and relatively small N mineralization rates in these fields. However, variation in texture did not explain variation in N mineralization of soils with inundation periods of 3–8 months. Instead, the anaerobic N mineralization correlated positively with Na pyrophosphate‐extractable Fe and negatively with pH (both at P < 0.01). Thus, pH and Fe content, rather than soil N content, clay mineralogy or texture, explained the substantial variation in anaerobic N mineralization of paddy soils in Bangladesh inundated for 3–8 months. It is not known if these relationships between net evolution of ammonium in soil and pH and Fe content are causal or indirect. Elucidation of these mechanisms would greatly further our comprehension of the biochemistry of the young ‘floodplain soils' with relatively low content of pedogenic oxides throughout southeast Asia.
Dissolving, trapping and detrapping mechanisms of hydrogen in bcc and fcc transition metals

First-principles calculations are performed to investigate the dissolving, trapping and detrapping of H in six bcc (V, Nb, Ta, Cr, Mo, W) and six fcc (Ni, Pd, Pt, Cu, Ag, Au) metals. We find that the zero-point vibrations do not change the site-preference order of H at interstitial sites in these metals except Pt. One vacancy could trap a maximum of 4 H atoms in Au and Pt, 6 H atoms in V, Nb, Ta, Cr, Ni, Pd, Cu and Ag, and 12 H atoms in Mo and W. The zero-point vibrations never change the maximum number of H atoms trapped in a single vacancy in these metals. By calculating the formation energy of vacancy-H (Vac-Hn) complex, the superabundant vacancy in V, Nb, Ta, Pd and Ni is demonstrated to be much more easily formed than in the other metals, which has been found in many metals including Pd, Ni and Nb experimentally. Besides, we find that it is most energetically favorable to form Vac-H1 complex in Pt, Cu, Ag and Au, Vac-H4 in Cr, Mo and W, and Vac-H6 in V, Nb, Ta, Pd and Ni. At last, we examine the detr.
Liquid‐like ordered colloidal suspensions: The influence of the particle concentration

The density of dependence of the static structure factor S(Q) of liquid‐like ordered colloidal suspensions is investigated by light scattering techniques. We found that variation of the particle number density even by a factor of 8 produced only a modest change of the height of the first peak of S(Q). In order to obtain a consistent theoretical description of S(Q) at various particle number densities, the effective charge Z*p of the particles and the Debye screening parameter κ* were calculated on the basis of the Poisson–Boltzmann–Cell (PBC) model and the Poisson–Boltzmann–Jellium (PBJ) model, respectively. The resulting Z*p and κ* values were used to calculate S(Q) via the rescaled mean spherical approximation (RMSA). It is found that a consistent description of the density dependence of S(Q) is possible with the PBC model. By contrast, the PBJ model predicts too weak a liquid‐like order than observed experimentally.
Mixed organic waste composting using rotary drum composter

A combination of vegetable waste, cattle manure and saw dust was utilised for high rate composting in a household rotary drum composter. It was found that temperature remained above 55? C for a period of two days, Faecal Coliforms and Faecal Streptococci decrease from 7.5 ? 108 to 5 ? 102 and 1.5 ? 107 to 5 ? 103 bacteria/g, respectively. Negligible VFAs production indicated full aerobic conditions. Nitrification occurred after sixth day i.e., when temperature dropped below 40? C. BOD/COD ratio decreased up to 12 days and remained stable thereafter, indicating the stability of compost in terms of biodegradation.
Impact of Alternative Farm Management Practices on Nitrogen Pollution of Groundwater: Evaluation and Application of CENTURY Model

An important environmental issue for Canadian agriculture is groundwater-N pollution. Addressing this issue requires understanding the impact of farm management practices on nitrate leaching, but empirical studies are limited by resource and time constraints. The CENTURY model was adapted to southwestern Ontario agricultural conditions and then used to predict short- to medium-term effects of crop choice and crop rotation pattern, fertilizer management, and tillage practice on N leaching. CENTURY model evaluation suggests that aboveground C production (translated into grain yield) and N leaching predicted by CENTURY provide good representation of results from actual field-measured data. Results suggest that relative reduction in groundwater-N leached is markedly greater at higher rates of fertilizer application than at lower (below the maximum economic rate of N fertilization) rates. Although tillage may not dramatically affect N leaching, other farm management practices such as crop type and crop rotation choice, along with the carry-over effects of these management activities on mineralization of soil organic matter, may have a significant effect on N leaching from the root zone.
Hysteresis in Crystalline Swelling of Smectites

Abstract Hysteresis in crystalline swelling of smectites was investigated with respect to the surface properties of five reference smectites. First, the samples were Na saturated and equilibrated with either 3 M NaCl or distilled water to establish initial basal spacings of 15.5 and >40 A, respectively. Then the samples were equilibrated with NaCl solutions ranging from 0.35 to 3 M, to establish osmotic control of crystalline swelling. Basal spacings of the equilibrated clays were measured by X ray diffraction, and hysteresis was quantified as the difference in weighted-average H2O activities in the equilibration solutions for the adsorption (15.5 to 19 A) and desorption (19 to 15.5 A) transitions. The magnitude of hysteresis was similar for all five smectites and was not significantly correlated with surface charge density, percentage of tetrahedral charge, or surface area. The cause of hysteresis in crystalline swelling is attributed to both intrinsic and extrinsic processes. Intrinsic hysteresis is an inherent consequence of changes in the expansion and attraction energy levels during swelling and is believed to be caused by rigidity of the clay-water system. Extrinsic hysteresis is caused by factors that contribute additional rigidity to smectite quasicrystals, primarily thick quasicrystals. Sample history influences the magnitude of the extrinsic hysteresis.
Evaluating the impact of Hazelwood mine fire event on students’ educational development with Bayesian interrupted time-series hierarchical meta-regression

Background: Disasters and other community-wide events can introduce significant interruptions and trauma to impacted communities. Children and young people can be disproportionately affected with additional educational disruptions. With the increasing threat of climate change, establishing a timely and adaptable framework to evaluate the impact of disasters on academic achievement is needed. However, analytical challenges are posed by the availability issue of individual-level data. Methods: A new method, Bayesian hierarchical meta-regression, was developed to evaluate the impact of the 2014 Hazelwood mine fire (a six-week fire event in Australia) using only aggregated school-level data from the standardised National Assessment Program-Literacy and Numeracy (NAPLAN) test. NAPLAN results and school characteristics (2008-2018) from 69 primary/secondary schools with different levels of mine fire-related smoke exposure were used to estimate the impact of the event. Using an interrupted time-series design, the model estimated immediate effects and post-interruption trend differences with full Bayesian statistical inference. Results: Major academic interruptions across NAPLAN domains were evident in high exposure schools in the year post-mine fire (highest in Writing: 11.09 [95%CI: 3.16-18.93], lowest in Reading: 8.34 [95%CI: 1.07-15.51]). The interruption was comparable to a three to four-month delay in educational attainment and had not fully recovered after several years. Conclusions: Considerable academic delays were found as a result of a mine fire, highlighting the need to provide educational and community-based supports in response to future events. Importantly, this work provides a statistical method using readily available aggregated data to assess the educational impacts in response to other disasters
High Performance Liquid Chromatographic Determination of Free Amino Acids in Shrimp

Abstract A reverse phase high performance liquid chromatographic method for the analysis of total free amino acids in shrimp, utilizing pre column fluorescence derivatization is described. The primary amino acids were treated with o-phthalaldehyde (OPA). The reaction products were separated on a Microsorb Short-ones 3-μm reversed-phase column with gradient elution development. 15-OPA amino acids were separated in 21 min. Secondary amino acids were reacted with 4-chloro-7-nitrobenzofurazan (NBD). The separation was carried out on a Lichrosorb RP-C18, 5μm column. Wild and cultured Mexican shrimp species (Penaeus vannamei) were analyzed. Free amino acid contents of glycine, alanine and proline were higher than those of other amino acids. Total Free amino acid content was significantly higher in cultured than wild shrimp. The OPA-retention time could be measured within ±0.1 relative standard deviation and the relative peak areas, based on the internal standard calculation methodology, were within ±3% or less.
HPLC-DAD Quantification of Phenolic Compounds Contributing to the Antioxidant Activity of Maclura pomifera, Ficus carica and Ficus elastica Extracts

Abstract The concentration and antioxidant activity of the known phenolics macluraxanthone, rutin, chlorogenic acid, and psoralen present in M. pomifera, F. carica, and F. elastica extracts were determined to evaluate the plant extracts potency as new antioxidant suppliers. The quantification of the compounds was obtained by HPLC-DAD. The antioxidant activity of plant extracts and compounds was evaluated using DPPH and ABTS methods. The results seem to indicate that these extracts can be promising as new antioxidant suppliers, particularly F. carica and F. elastica leaves because only about 30% and about 50%, respectively, of the total activity was due to the phenolics determined.
Polyacetylenverbindungen, 174. Über neue Spiroketalenolätherpolyine aus Arten des Tribus Anthemideae

Die Untersuchung einiger weiterer Arten des Tribus Anthemideae ergibt mehrere neue Acetylenverbindungen (6, 8, 17, 21, 22, 26, 27 und 28), die mit bereits bekannten Substanzen eng verwandt sind. Die biogenetischen Beziehungen werden diskutiert. Polyacetylenic Compounds, 174. New Spiro Ketal Enol Ether Polyynes from Species of the Tribe Anthemideae The investigation of some further species of the tribe Anthemideae gives several new acetylenic compounds (6, 8, 17, 21, 22, 26, 27 und 28) closely related to already known substances. Biogenetic relationships are discussed.
Instrumental Textural and Rheological Properties of Raw, Dried, and Cooked Noodles with Transglutaminase

Textural and rheological properties of raw, dried, and cooked noodles with microbial transglutaminase were evaluated by an instrumental texture analyser. Generally, the strength of the noodles significantly increased with microbial transglutaminase concentration from 0 to 1.0%. The cutting force of raw noodle is a good indicator to predict the strength of dried and cooked noodle products. Mechanical stress relaxation data of cooked noodles were fitted well by both Maxwell and Peleg-Normand models. The fitted parameters, λ1 and k2, were more sensitive to the changes in viscoelastic properties than k1 and %SR. Significant correlations were found between textural characteristics and stress relaxation parameters. Results of this study suggest that dried or cooked noodle with good quality can be produced by incubating with 0.5–1.0% microbial transglutaminase for 30 min at 30 °C.
Formation of Cagelike Intermediates from Nonrandom Cyclization during Acid-Catalyzed Sol-Gel Polymerization of Tetraethyl Orthosilicate

In the sol-gel synthesis of silica by the acid-catalyzed hydrolysis and condensation of tetraethyl orthosilicate (TEOS), the fractal dimension, density, and homogeneity of the gel depend strongly on reaction conditions such as the acid and water concentrations. However, 29 Si nuclear magnetic resonance shows that gel conversions of at least 80% are observed over a wide range of initial acid (10 -5 -10 -1 mol/L), water (4-22 mol/L), and TEOS (1.3-2.5 mol/L) concentrations. This is very high compared to the value predicted by random branching theory even under the worst possible negative first-shell substitution effect. Moreover, nonrandom cyclization is commonly evidenced in these systems by 29 Si NMR, Raman spectroscopy, and gas chromatography with mass spectroscopy. The gel conversions suggest that nonrandom cyclization reactions are strongly favored, and the development of conversions with time is consistent with the formation of compact three-dimensional cagelike intermediates. These are probably the same nanometer-scale objects shown by recent scattering and microscopy observations.
Mutual Diffusion Coefficient of Aqueous Sugar Solutions

The mutual diffusion coefficient of aqueous solutions with sugars of various molecular weight, obtained by drying experiment of the solution, was investigated for the effects of concentration, temperature and molecular weight of sugar.The mutual diffusion coefficient of dilute solution was correlated using Wilke’s diffusion factor. The concentration dependence was presented by linear relation of the logarithm of the diffusion coefficient vs. the sugar mole fraction regardless of temperature. The slopes of the linear relations were expressed by a power function of the molecular weight. From the linear relation, the activation energy was expressed also by linear relation of the sugar mole fraction, in which the slopes were expressed by the other power function of the molecular weight. The resultant estimation equation covers well for the temperature range 298–323 K and for the molecular weight range of sugars, from 180 for glucose to 6100 for maltodextrin.
Effects of Acidity on the Hydrothermal Synthesis of Kaolinite from Silica-Gel and Gibbsite

A comparative study is reported in which kaolinite has been hydrothermally synthesized at several pH conditions. The syntheses were carried out at 220 °C for 3 to 10 d with distilled water or acidic solutions using a mixture of silica-gel derived from alkoxide and gibbsite with a Si/Al ratio of 1:1 as the starting material. Use of acidic solution for the synthesis promotes the dissolution of the starting materials and leads to kaolinitization at an earlier stage of the reaction. However, the rate of kaolinitization is found to be rather slow, in comparison to the reaction with distilled water. The synthetic kaolinite was characterized by X-ray powder diffraction pattern. Kaolinite synthesized with distilled water was poorly grown for direction of the stacking. For example, crystallite size along the c*-axis = 155 Å, whereas kaolinite synthesized with acidic solution gave a higher crystallite size along the c*-axis, such as 253 Å in the case of the synthesis with 0.1 N HCl. Hinckley index of the synthetic kaolinite was varied from 0.35 to 0.80 by the acidity of the reaction. Different kaolinitization processes are implied by differences observed in the rate of kaolinitization, which has an influence on the nature of the stacking faults of the kaolinite.
Effect of polymorphic phase transformations in alumina layer on ignition of aluminium particles

The mechanism of aluminium oxidation is quantified and a simplified ignition model is developed. The model describes ignition of an aluminium particle inserted in a hot oxygenated gas environment: a scenario similar to the particle ignition in a reflected shock in a shock tube experiment. The model treats heterogeneous oxidation as an exothermic process leading to ignition. The ignition is assumed to occur when the particle's temperature exceeds the alumina melting point. The model analyses processes of simultaneous growth and phase transformations in the oxide scale. Kinetic parameters for both direct oxidative growth and phase transformations are determined from thermal analysis. Additional assumptions about oxidation rates are made to account for discontinuities produced in the oxide scale as a result of increase in its density caused by the polymorphic phase changes. The model predicts that particles of different sizes ignite at different environment temperatures. Generally, finer particles ignite at lower temperatures. The model consistently interprets a wide range of the previously published experimental data describing aluminium ignition.
Modification of phenol–formaldehyde resol resins by lignin, starch, and urea

Lignin-based chemicals, starch, and urea were used as modifiers for phenol–formaldehyde resol resins. The effects of the addition stage of the modifiers used in the synthesis of the resins and the type of modification reagent on the structures of the resins and their molar masses and reactivities were investigated. The modifications with corn starch and lignin promoted condensation; this was verified by increased molar masses and high ratios of methylene bridges to the sum of free ortho and para aromatic groups with respect to the corresponding reference resin without a modification reagent. The later the modifier was added to the resin condensation mixture, the more methylene bridges were formed with respect to the amounts of free ortho and para aromatic groups. In addition, when urea or wheat starch was added in the later condensation stage, the final condensation also reached high stages. The modifications with lignosulfonate and starch, as well as the early addition of urea, enhanced p–p′ bridge structures. The lowest condensation stage and, therefore, the highest reactivity were found when wheat starch was added with the starting reagents. The curing heat of the wheat-starch-modified resins decreased according to the deferred addition point of starch. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 582–588, 2003
Hydrogen Peroxide, Hydroxyl Ammonium Nitrate, and Other Storable Oxidizers

A liquid oxygen is in many respects the ideal oxidizer, its cryogenic nature makes it unsuitable for many applications. The plumbing and feed systems are complicated dramatically when using this fluid because provisions for boiloff and potential geysering must be included and cryogenic valves and pumps must be used for fluid control. In many military and space applications, oxidizer storability is desired, if not required, under mission constraints. For these reasons, there has always been ample motivation for study and development of hybrid rockets using storable oxidizers. Efforts dating back over the past 40 years have included study of such liquids/fluids as nitrogen tetroxide, nitric acid [and its variants red-fuming nitric acid (RFNA) and inhibited RFNA (IRFNA)], hydrogen peroxide (HP), hydroxyl ammonium nitrate (HAN), nitrous oxide, and other energetic liquids. Whereas there have been limited efforts on reverse hybrids using solid oxidizers and storable liquid fuels, these configurations are generally undesirable due to reduced safety and performance as compared to the traditional scheme. Gaseous oxygen is another storable oxidizer of note, but its poor density relegates it mainly to use in laboratory and ground demonstrations [1–6]. Table 1 summarizes some of the physical properties of these storable oxidizers. Nitric acid is particularly attractive for applications demanding low temperatures within the operating range due to its very low freezing point. Nitrogen tetroxide
Synthesis and properties of poly(acrylamide-aniline)-grafted gum ghatti based nanospikes

In this work, we have synthesized poly(acrylamide-aniline)-grafted gum ghatti based crosslinked conducting hydrogel via a two-step synthesis method. The first step involved the microwave assisted synthesis of a semi-interpenetrating polymer network (semi-IPN) based on acrylamide and gum ghatti using N,N′-methylene-bis-acrylamide and ammonium persulfate as a crosslinker-initiator system. The semi-IPN has been observed to exhibit as much as 2183% swelling in aqueous solution. The effect of several variables such as time, solvent, pH, microwave power, crosslinker amount, aniline concentration, initiator concentration and monomer concentration on the swelling capacity was explored. In the final step, polyaniline was entrapped within a semi-IPN (optimized reaction condition) followed by doping with hydrochloric acid, which leads to the formation of conducting IPN. The synthesized hydrogels, as monitored by the swelling behaviour were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. Finally, the synthesized crosslinked networks have been used in malachite green (MG) adsorption. The result indicates that IPN of poly(acrylamide-aniline)-grafted gum ghatti are potential candidates for dye removal from water.
Thermal oxidation kinetics for a poly(bismaleimide)

The thermal oxidation of poly(bismaleimide) of the F655-2 type, supplied by Hexcel-Genin, was studied by isothermal gravimetry at 180, 210, and 240°C and various oxygen pressures ranging from 0 to 1.2 bar. Comparison of various sample thicknesses and visible microscopy observations on bulk aged samples shows that the whole oxidized layer has a depth of about 75 μm at 240°C, 138 μm at 210°C, and 229 μm at 180°C. An attempt was made to build a kinetic model to predict this depth. It is based on a differential equation in which O 2 diffusion and its consumption rate, r(C), are coupled, C being the O 2 concentration. Its resolution needs two sets of experiments: the first one to determine the O 2 diffusivity and solubility in the polymer, and the second one to determine r(C). The mathematical form of r(C) is derived from a mechanistic scheme of radical chain oxidation in which initiation is mainly due to POOH decomposition. This expression contains two kinetic parameters, α and β, the values of which are determined from the experimental curves of mass loss rate against O 2 pressure (in the stationary state). The theoretical predictions, at each temperature under consideration, are in excellent agreement with experimental results.