Miracle-dz/UniFAR-FTUs huggingface dataset:
The annual net flux of carbon to the atmosphere from changes in land use 1850–1990*

Rates of land-use change, including clearing for agriculture and harvest of wood, were reconstructed from statistical and historic documents for 9 world regions and used, along with the per ha changes in vegetation and soil that result from land management, to calculate the annual flux of carbon between land and atmosphere. Between 1850 and 1990, changes in land use are calculated to have added 124 PgC to the atmosphere, about half as much as released from combustion of fossil fuels over this period. About 108 PgC are estimated to have been transferred from forests to the atmosphere as a result of human activity, 2/3 from tropical forests and 1/3 from temperate zone and boreal forests. Another 16 PgC were lost from non-forests, largely as a result of cultivation of mid-latitude grassland soils. About 800 × 10 6 ha of forest were cleared for agricultural purposes, and approximately 2000 × 10 6 ha were harvested. Conversion of forests to agricultural lands released 105 PgC; harvest of wood released about 20 PgC. These estimates of release include the accumulations of carbon in wood products (17 PgC) and woody debris (4 PgC), the losses of carbon from oxidation of wood products, woody debris, and soil organic matter (373 PgC in total), and the accumulations of carbon in forests recovering from harvest and in the fallows of shifting cultivation (249 PgC). Over the decade of the 1980s the annual net flux of carbon from changes in land use averaged about 2.0 PgC yr −1 , higher than the 1.6 PgC yr −1 estimated previously. Almost all of this flux was from tropical regions, where rates of deforestation averaged approximately 15 × 10 6 ha yr −1 . Outside the tropics, regrowth of forests logged in earlier years largely balanced the losses of carbon from oxidation of wood products. DOI: 10.1034/j.1600-0889.1999. 00013.x
Advocating Science for All: An Interview with Peter J. Fensham.

After providing some glimpses of his private life, Peter Fensham, a leading figure of the prestigious Faculty of Education, Monash University (and now emeritus professor at Queensland University, Brisbane, Australia), gives some suggestions about the conditions that help students to learn meaningfully. He began his career in the field of physical chemistry and then became an international authority in science education. His dedication to students and commitment to teaching a learner-centered science is palpable in many of his comments. This interview touches on many of the themes he addressed in numerous studies and research: the curriculum, the qualities of the expert teacher, and the decline of standards in schools. Although he is a supporter of a constructivist approach to teaching chemistry, he criticizes the extreme views of constructivism and explains the origin of his inner strength that made him a champion of 'science for all'.
PHOSPHORUS AVAILABILITY AND SORPTION IN AN ATLANTIC COASTAL PLAIN WATERSHED DOMINATED BY ANIMAL‐BASED AGRICULTURE

The Inland Bays watershed in southern Delaware is dominated by a large and growing poultry industry that uses land application as the primary means for disposal of manure. Runoff and drainage waters from an extensive ditch drainage system in the area eventually enter the Inland Bays. Phosphorus in these waters has been suggested as a contributing factor to eutrophication of the Inland Bays. Soil test P (STP, Mehlich 1, 0.05N HCI + 0.025N H2SO4) levels in cultivated and field border areas and P sorption maxima (PSM) were determined for selected profiles of agricultural fields and non-cultivated field borders. Relationships between PSM and soil properties and a rapidly determined p sorption index (PSI) were also investigated. STP in cultivated topsoils from 48 sites ranged from 43 to 632 mg/kg and from 42 to 568 mg/kg at 0–5 and 5–20 cm, respectively, relative to a high value for STP for agronomic crops of 35 mg/kg. STP levels were consistently greater in cultivated profiles than in field borders. Downward movement of P in some cultivated profiles occurred to a depth of 40 cm. PSM ranged from 95 to 2564 mg/kg in cultivated soils and from 200 to 2000 mg/kg in field borders. PSM was highly correlated (r = 90) with clay content and was consistently higher in subsoil horizons. When clay contents were similar, P sorption was usually greater in field borders than in cultivated fields. PSI was highly correlated with PSM (r† = 0.94) except when PSI exceeded 1400 mg/kg. This study suggests that past and current P management practices in the Inland Bays have increased soil P levels in this watershed to levels that may require much more intensive management of manure and fertilizer P in the future. Although subsoil horizons may prevent direct P leaching into groundwater, the high P values noted at the 0 to 5-cm depth and in some subsoils point to the need to assess the potential for soluble P losses in runoff and drainage waters.
Synthesis and Characterization of Some Monomeric and Dimeric Silver(I)-Phosphine Complexes With N-Donor Bridging Ligands

The monomeric complexes [Ag(PPh3)2]X (X = ClO4 − or NO3) was synthesized by a metathesis reaction of [Ag2(PPh3)4(μ-SO4)] with BaX2 (where X = ClO4 − or NO3 −) in ethanol. The reactivity of [Ag(PPh3)2]X (where X = ClO4 − or NO3 −) with some potential N-donor bridging ligands viz. 4,4′ bipyridine and pyrazine yielded dimeric complexes of the type [Ag2(PPh3)4(μ-L-L)]X2 (where L-L = 4,4′-bipyridine or pyrazine, and X = ClO4 − or NO3 −). All these complexes were characterized by infrared spectroscopy, conductivity measurements, cyclic voltammetry, 1H NMR, and electronic spectroscopy.
Effects of oxygen on diamond growth

In situ mass spectral measurements of gas composition at the substrate surface were made during filament‐assisted diamond growth. The input gases were various mixtures of CH4, O2, and H2 chosen in order to discern the effects of oxygen addition on diamond formation and growth. The gas phase chemistry was modeled as a one‐dimensional flow reactor, and the measured and calculated species mole fractions were in good agreement. The model was then used to estimate mole fractions of several atomic and radical species which could not be measured. We find that addition of O2 has only a small effect on the radical mole fractions. However, O2 can reduce the effective initial hydrocarbon mole fraction, which is important because higher quality diamond is grown at a lower initial hydrocarbon mole fraction. Most important, perhaps is that O2 addition leads to the formation of sufficient gas phase OH to remove nondiamond (pyrolytic) carbon from the film. Thus, O2 addition allows diamond films to be grown under composit.
Homogeneous Catalysis of Ethyl tert-Butyl Ether Formation from tert-Butyl Alcohol in Hot, Compressed Liquid Ethanol

Ethyl tert-butyl ether (ETBE) and isobutene are the only significant products of the sulfuric acid ({le} 0.001 M) catalyzed reactions of tert-butyl alcohol in water/ethanol mixtures at 3 MPa and 170 C. Equilibrium is established after a few minutes or less. A 10 parameter kinetic model which embodies a first order elimination reaction and a first order nucleophilic substitution reaction adequately describes the influences of reactant (ethanol, water, and tert-butyl alcohol) concentrations, acid concentration, and residence time on product yields. The fit of the model to the data improves when the influence of water on the solvent`s dielectric constant is included by the addition of two more parameters. One finding of the simulation effort is that protonated isobutene (the key ingredient in ETBE formation) forms only from tert-butyl alcohol (not isobutene) under the conditions employed in this work. Thus tert-butyl alcohol should be preferred over isobutene as a reactant for ETBE synthesis at elevated pressures and temperatures.
Dependence of Sulfadiazine Oxidative Degradation on Physicochemical Properties of Manganese Dioxides

Manganese dioxides as active oxidants are the common minerals in environment, and different types of manganese dioxides may exhibit varied oxidative activity. In this study, eight manganese dioxides were used to conduct sulfadiazine (SD) oxidative degradation. SD can be oxidatively degraded and even mineralized by these manganese dioxides, and the toxicity of the SD sample can also be reduced significantly. The experiments in this study demonstrated that the kinetic reaction rate constant k values of SD degradation strongly depended on the physicochemical properties of different manganese dioxides, including average oxidation state (AOS), reductive potential (Eh), pH at the point of zero charge (pHPZC), and apparent activation energy (Ea). The k values were positively correlated with the AOS and Eh, while negatively correlated with pHPZC and Ea. The values of these physicochemical properties can be used to quantitatively estimate the oxidative activity of a manganese dioxide to some extent for better unde.
Micromechanical observation of the kinetics of biomolecular interactions

Resonant microcantilevers have recently enabled the label-free detection of biomolecules. Here, we observed the kinetics of biomolecular interactions such as antigen-antibody interactions and/or DNA hybridization based on a resonant frequency shift, obeying Langmuir kinetics, measured in a buffer solution. It is shown that the kinetics of DNA adsorptions on the surface is governed by intermolecular interactions between adsorbed DNA molecules. It is also shown that the kinetics of DNA hybridization is determined by the intermolecular interaction. It is implied that resonant microcantilever in buffer solution may allow for gaining insights into the kinetics of various molecular interactions.
Synthesis of Ni Nanoparticles by Hydrolysis of MgNi2

MgNi2 has been shown to exhibit a hydrolysis behavior similar to that previously found for Mg2Ni. The Ni nanoparticles prepared by hydrolysis of MgNi2 were spherical in shape with a mean diameter of about 16 nm. Utilizing the hydrolysis behavior of MgNi2 to produce Ni nanoparticles offers a higher efficiency than by using Mg2Ni, saves raw material and reduces any pollution resulting from the dissolution of the hydrolysis byproduct (Mg(OH)2) by using an acid.
IR Observation of Selective Oxidation of Cyclohexene with H2O2 over Mesoporous Nb2O5

Liquid-phase catalytic oxidation of cyclohexene by H2O2 (35 wt %) over mesoporous Nb2O5 showed considerable conversion and high selectivity for both cis- and trans-1,2-cyclohexanediols in acetonitrile solvent. The mesoporous structure of the catalyst, in addition to its high surface area, was considered to be advantageous for the reaction due to more frequent interaction of molecules with active sites inside pores. Gradual formation of 1,2-cyclohexanediol from the reaction of adsorbed cyclohexene with diluted (10 wt %) H2O2 was observed at room temperature by an in situ infrared (IR) method. The absence of observation of an IR spectrum of 1,2-epoxycyclohexane confirmed that the hydrolysis of the oxidation product occurred immediately. In addition to the conventional stepwise oxidation and hydrolysis to produce 1,2-cyclohexanediol, a direct hydroxylation of cyclohexene was proposed: the production of cis-1,2-cyclohexanediol with about a half amount of trans-1,2-cyclohexanediol suggests the activation of H2.
Emissions of N2O and NO associated with nitrogen fertilization in intensive agriculture, and the potential for mitigation

Abstract. Increases in the atmospheric concentrations of nitrous oxide (N2O) contribute to global warming and to ozone depletion in the stratosphere. Nitric oxide (NO) is a cause of acid rain and tropospheric ozone. The use of N fertilizers in agriculture has direct and indirect effects on the emissions of both these gases, which are the result of microbial nitrification and denitrification in the soil, and which are controlled principally by soil water and mineral N contents, temperature and labile organic matter.
A new approach for measuring the effect of a monolayer on molecular transfer across an air/water interface using scanning electrochemical microscopy

A new approach is described for the quantitative study of the effect of a monolayer on solute transfer rates across an air/water interface. The technique is illustrated through measurements of oxygen transfer across a monolayer of 1-octadecanol as a function of compression. The experimental approach uses an inverted ultramicroelectrode (UME), positioned in the water phase in a Langmuir trough close to the air/water interface to induce the transfer of oxygen from air to water via the reduction (and depletion) of oxygen. The steady-state current response, measured as a function of UME−interface separation at various monolayer compressions, demonstrates that the rate of oxygen transfer is governed primarily by the accessible free area of the interface.
Photocatalytic Oxidation of 2-Chloroethyl Ethyl Sulfide on TiO2−SiO2 Powders

The photocatalytic oxidation of 2-chloroethyl ethyl sulfide (2-CEES, a simulant for mustard gas) on high area TiO2−SiO2 powder has been studied by transmission infrared spectroscopy. It has been found that the photocatalytic oxidation of 2-CEES occurs on the surface of TiO2−SiO2 at 200 K with an appreciable rate, causing 40−50% depletion of the initial surface coverage before the photoreaction slows down appreciably. In addition to 2-CEES, we have also studied the photooxidation of diethyl sulfide (DES), as a comparison, to test the role of Cl substitution in the 2-CEES molecule. With both 2-CEES and DES, partially and fully oxidized products are observed. By comparison of the spectral developments during the photooxidation of 2-CEES and DES, it appears that the presence of the chlorine substituent in 2-CEES is not strongly influential in the photooxidation sequences for this molecule. The 2-CEES molecule is hydrogen-bonded to the Si−OH groups by both the Cl and the S moieties, and photooxidation leads to.
Composition of the Essential Oil of Syzygium cordatum Hochst. ex Krauss

Abstract The hydrodistilled oil of Syzygium cordatum Hochst. ex Krauss was analyzed by GC and GC/MS. The analysis revealed the presence of 22 compounds (83% of the oil) of which limonene (21.8%) and globulol (16.0%) were the major components. The identified components comprised of 8 monoterpenes and 12 sesquiterpenes. The other two compounds identified were hexanol and (Z)-3-hexenol.
MIGRATION OF STYRENE MONOMER FROM POLYSTYRENE PACKAGING MATERIALS INTO FOOD SIMULANTS

Migration studies of residual styrene from Impact Polystyrene cups into soybean oil were carried out at several temperatures. Experimental migration curves were compared to theoretical ones calculated from diffusion-type equations; the former showed higher (by approximately 20%) migration rates and equilibrium styrene concentrations in the oil. Even though the residual styrene was in most cases below 0.1% (far below the levels allowed by the FDA), significant migration occurred, and the resulting styrene concentrations in the oil exceeded the previously determined organoleptic threshold by more than an order of magnitude. The diffusion coefficient of styrene in polystyrene was found to decrease and the partition coefficient to increase with the decrease of residual styrene indicating an increase in monomer-polymer interaction.
Molecular Growth of Polyoxometalate Architectures Based on [−Ag{Mo8}Ag−] Synthons: Toward Designed Cluster Assemblies

The interaction of silver(I) cations with octamolybdate [Mo8O26]4− has been investigated by applying the principles of the building-block concept to the well established silver−octamolybdate reaction system. The self-assembly of dimeric {Ag2} linkers allows the formation and isolation of chains and networks where [Mo8O26]4− clusters are cross-linked by silver(I) cations. The influence of the solvent on the overall topology has been studied, and the role of the counterion on the resulting structure has been highlighted in each assembly. Fine-tuning of the metal−metal distances of the dimeric {Ag2} linking units has been achieved by using different coordinating solvents which act as bridges. Five compounds based on silver octamolybdate building blocks have been isolated, including an uncommon intermediate ((Ph4P)2[Ag2(CH3CN)2(Mo8O26)]), three one-dimensional polymeric chains ([Ag(C7H12O2N)(CH3CN)]2n[Ag2(CH3CN)2(Mo8O26)]n·2CH3CN, (Ph4P)2n[Ag2(DMF)2(Mo8O26)]n·2DMF, and (H2NMe2)2n[Ag2(DMF)2(Mo8O26)]n·2DMF), an.
The Study of an Inorganic Gel for Profile Modification in High-Temperature and Low-Permeability Sandstone Reservoirs

Chemical water control technique has been successfully used to improve oil recovery of mature waterflooding reservoirs. However, for high-temperature and low-permeability sandstone reservoirs, not many options are available. An inorganic gel composed of aluminum chloride hexahydrate as gelling agent and urea as an activator was developed. Based on the proper gelation time and degree of syneresis, the optimum mass ratio of aluminum chloride and urea was 1:0.625. According to the gel strength and economical cost, the reasonable concentration of aluminum chloride should range from 3.0% to 6.0%. Gel compatibility with various formation brines showed that the gel could tolerate sodium chloride concentrations up to 80 g·L −1 and calcium chloride concentrations up to 40 g·L −1. Long-term thermal stability and sandpack flow results showed that after aging for 60 days at 110°C, the gel showed approximately 82% permeability reduction when about 16% syneresis was observed in bulk samples.
Sulfonation reactions of (β-carbolines

The homogeneous sulfonations of (β-carboline derivatives norharmane 2, harmane 3, harmine 4, harmol 5, -N,N′-dimethyl-harmane 6, and harmaline 7 have been studied in 80–90% w/w sulfuric acid solutions at 25 °C. Ultraviolet–visible and 13C nuclear magnetic resonance spectra and chemical analysis of the reaction mixtures show that for all the substrates studied only C-6 sulfonated products are obtained. The sulfonation reactions of the benzene unsubstituted substrates 2, 3, and 6 and the partially aromatic substrate 7 proceed by direct electrophilic attack of the H3SO4+ cation on the benzene ring of the (β-carboline skeleton. Sulfonation of 4 and 5 at the lower sulfuric acid concentrations is effected by the H3SO4+ entity. With increasing sulfuric acid concentration there is a gradual changeover of the sulfonating entity from H3SO4+ to H2S2O7. The different mechanisms of sulfonation are discussed. Keywords: β-carbolines, sulfonation, kinetics.
The Melting Behaviors of the Bimetallic Cluster ConCu55-n(n=0~55)

The melting behaviors of ConCu55-n(n=0~55) bimetallic cluster were studied by using semi-empirical Gupta potential combined with molecular dynamics simulations. The melting point of the ConCu55-n(n=0~55) cluster shows itself the trend of going up, accompanied by the increasing of the Cobalt atomicity. However, it is between Co55 and Cu55 elementary cluster for melting point overall. Meanwhile the variation in the width of pre-melting temperature is greater, if around n0 or n55, but it is lesser nearly n55/2(namely Co and Cu at the same atomicity). In addition, the saturation point of specific heat capacity can be determined corresponding to the peak of Lindemann index.
Magnetic anisotropic properties of Pd/Co/Pd trilayer films studied by X-ray absorption spectroscopy and magnetic circular dichroism

We study the magnetic anisotropic properties of as-grown and annealed Pd/Co/Pd trilayer films based on their atomic and electronic structures using extended X-ray absorption fine structure (EXAFS), X-ray absorption near edge structure (XANES) spectroscopy and magnetic circular dichroism (XMCD) measurements. The annealed film exhibits interesting perpendicular magnetic anisotropy (PMA) whereas the as-grown film exhibits in-plane anisotropy. Cross-sectional transmission electron microscopic analysis together with the Co K-edge EXAFS results confirm the formation of an ordered-alloy CoPd phase in the annealed film, whereas the as-grown film has an hcp Co-like phase. Co L3,2-edge XMCD measurements reveal an enhanced ratio of the Co 3d orbital to spin moments of the annealed film providing evidence of the observed PMA upon annealing.
An Investigation of Electrostatic Assist in Dynamic Wetting

Electrostatic assist is widely used in liquid coating processes to promote high coating speeds by postponing the onset of air entrainment. However, very little research has been published on the interaction of electrostatic forces with coating flows. The present work seeks to address this deficiency and to show the way in which an electrostatic field can promote dynamic wetting. A simple theory is developed in which the electrostatic field and the resultant forces are treated independently of the liquid flow. Electrostatic equations are derived and incorporated within the molecular kinetic theory of dynamic wetting. Experimental evidence is presented which demonstrates the utility of this approach.
Toward Perfect Control of End Groups and Polydispersity in Poly(3-hexylthiophene) via Catalyst Transfer Polymerization

We report the influence of the active Grignard monomer formation on the end groups and polydispersity of poly(3-hexylthiophene) (P3HT) for the catalyst transfer polymerization. The rate of the active Grignard monomer formation of 2,5-dibromo-3-hexylthiophene using t-BuMgCl was studied using 1H NMR. Only in the absence of unreacted/excess t-BuMgCl, polymers with 100% H/Br end groups were formed. If the active Grignard monomer formation was incomplete and thus unreacted t-BuMgCl remained, the end groups depended on the polymerization time; the ratio of H/Br to H/H end groups decreased with increasing time. LiCl was shown to accelerate the active Grignard monomer formation but negatively affects the regioregularity to a small extent. It also increases the molecular weight of P3HT when used in combination with Ni(dppp)Cl2 as a catalyst. Further, MeOH as a quenching reagent was identified to cause chain−chain coupling and hence an increase in the polydispersity. Thus, important parameters influencing the kinet.
Caching and Forwarding in Named Data Networking based MANETs

Named Data Networking (NDN) is a newly proposed future Internet paradigm in which communication is based on content names irrespective of their locations. In NDN-based mobile ad hoc networks (MANETs), the status of nodes is extremely unstable because of attenuation of the signal, channel error, and channel fading. Such instability can cause various issues (e.g., packet collisions, flooding, data redundancy, packet retransmissions). In this paper, to cope with these issues, we have proposed a novel protocol, named location-aware on-demand multipath caching and forwarding (LOMCF) for NDN-based MANETs. Simulation results show that the proposed protocol performs better as comparing to the other protocols in terms of content retrieval time and Interest retransmissions.
Effect of temperature gradients on the efficiency of capillary zone electrophoresis separations

Influence de la chaleur generee dans les tubes sur l'efficacite du systeme electrophoretique. Il semblerait que seul les profils paraboliques de temperatures decrivent les gradients de temperatures de maniere correcte. Optimisation des conditions operatoires pour minimiser les effets indesirables des gradients thermiques